Bladder, Urethra, and Cloacal Exstrophy Flashcards
What anomalies make up the spectrum of the Exstrophy-Epispadias complex?
- Epispadias: The urethra is a partial or complete open plate on the dorsal penis. There is always severe dorsal chordee and it can be associated with vesico-ureteric reflux (VUR) and urinary incontinence.
- Classic bladder exstrophy (CBE): There is pubic diastasis with subsequent diastasis of the anterior abdominal wall. The bladder is an open plate often associated with congenital pseudo-polyps and it is incarcerated within the abdominal defect in an extraperitoneal position. The umbilical cord is usually lower in the abdomen compared to normal children. It is always associated with epispadias and the length of the urethral plate represents a critical factor in the reconstruction.
- Cloacal exstrophy (CE): It is one of the most severe congenital malformations compatible with life. Over 70% of the patients have severe associated anomalies including spinal dysmorphism and limbs abnormalities. There is extreme pubic diastasis and an omphalocele which both contribute to a large anterior abdominal wall defect. Two hemi-bladders are incarcerated in the abdominal defect and between them there is the cecum which is opened, and the ileum prolapses through the defect like an elephant trunk.
- Exstrophy variants: Partial manifestations of the above anomalies, which may lack symmetry in the sagittal plane.
There is significant variability of clinical manifestations and it is imperative to rule out associated anomalies.
Which embryological structure is commonly implicated in the pathogenesis of exstrophic anomalies?
• The cloacal membrane.
By the 4th week of gestation, the cloacal membrane forms the ventral wall of the urogenital sinus.
With further development, mesoderm fuses in the midline to form the lower abdominal wall with simultaneous caudal progression of the urorectal septum to separate the cloaca into the urogenital canal and rectum.
The Marshall and Muecke’s theory states that rupture of the cloacal membrane after complete separation of the GU and GI tracts results in CBE and prior to descent of the urorectal septum results in CE.
Epispadias occurs when there is failure of midline mesodermal fusion of the most distal part of the anterior cloacal membrane.
Normally the bladder forms around the 4th–8th week of gestation and represents the most anterior lower abdominal organ.
The two hemi-bony-pelvises form laterally to the sacrum and subsequently start to internally rotate which completes around the 10th week of gestation with the formation of the pubic symphysis.
The Cervellione’s theory speculates that the bladder remains trapped between the two pubic bones during their migration to the midline and the detrusor fuses to the pubic bones and the lower abdominal wall leading to perforation of the bladder.
The positive intra-abdominal pressure inverts the bladder ‘inside- out’.
The corpora cavernosa remain attached to the pubic bones and cannot externally rotate as normally happens with the consequent dorsal chordee.
What is the risk of recurrence of exstrophy in the family of a known index case?
Current counselling recommendations:
• 1% sibling recurrence
• 1:70 chance of transmission from parent to child.
What is the prevalence of CBE, CE, and epispadias?
The following figures are according to a recent European prospective trial [5]:
• Male epispadias ~1 in 101,000
- Female epispadias ~1 in 1,300,000
- CBE ~1 in 46,000. M:F 3:1
- CE ~1 in 317,000. M:F 6:1.
What is the rate of associated anomalies in CBE, CE, and epispadias?
- Epispadias ~3%: renal, chromosomal [5]
- CBE ~5%: renal, chromosomal, cardiac, anorectal malformation[5]
- CE ~71%: Gastrointestinal 65% (malrotation, short gut, duodenal atresia), Sacral agenesis 60%, spinal dysraphism 50%, orthopaedic 40% (club foot, hip dysplasia), cardiovascular <10%, and renal anomalies 7% (ectopic kidney, agenesis).
What antenatal ultrasound findings suggest a diagnosis of an exstrophy- epispadias complex?
- Failure to visualize the bladder (usually visible at ~14 weeks gestation)
- Lower abdominal wall mass
- Low-set umbilical cord
- Abnormal genitalia
- Widening of the iliac crests.
Data suggests that approximately 25% of bladder and cloacal exstrophy patients are detected antenatally [5].
What are the key external characteristics of CBE in male and female patients?
The bladder is open on the lower abdominal wall and the urothelium fully exposed. In males, the penis is short and wide with a short urethral plate and a dorsal chordee.
In females, the clitoris is bifid with the labia displaced laterally.
The vagina is displaced anteriorly and the mons pubis is absent.
In both sexes, the pubic symphysis is widely separated with divergent recti muscles.
What is the rate of inguinal hernias in patients with bladder exstrophy?
> 80% males >10% females.
Indirect inguinal hernias are commonly associated with bladder exstrophy [1, 2].
The wide pubic diastasis and external rotation of the anterior pelvis means that the internal and external rings lie in an anterior-posterior plane rather than the usual oblique plane seen in non-exstrophy children.
In addition to ligation of the patent processus vaginalis (PPV), what additional step must be undertaken during inguinal hernia repair in exstrophy patients?
• Narrowing of the internal ring.
This operative step, incorporating simple absorbable sutures, reduces the hernia recurrence rate.
Care must be taken to not strangulate the spermatic cord.
A term baby is born with CBE and is awaiting operative repair. What pre-operative measures must be taken during this period?
A hydrated gel dressing or plastic wrap is secured over the bladder and changed daily with normal saline irrigation.
Parents must be warned about the possibility for the baby to develop an inguinal hernia and occasionally rectal prolapse.
Patients with CBE often have no life-threatening anomalies and should be encouraged to remain with their recovering mothers until surgical repair is planned.
Feeding need not be restricted and breast-feeding encouraged.
Antibiotic prophylaxis is usually not required.
Pre-operative renal ultrasound is necessary to rule out upper tract dilatation and as a baseline for future ultrasound studies.
Spinal ultrasounds are necessary to rule out spinal cord anomalies.
In CE, an echocardiogram is always needed due to the higher rate of cyanotic heart disease (<10%) [1].
Antibiotics are also needed peri-operatively.
What are the pathological hallmarks of exstrophic bladders?
Exstrophic bladders demonstrate a similar amount of type 1 collagen but a 3-fold increase in type 3 collagen compared to controls [6].
Patients with adequate bladder capacity post closure demonstrate a significant decrease in the ratio of collagen to smooth muscle, provided the bladder remained infection free [6].
Based on experimental studies, exstrophy patients have similar cholinergic receptor density and binding affinity, but a significant decrease of myelinated nerves per field [6].
What are the key external characteristics of CE?
There is a central hind-gut plate with two separated bladder halves.
The ileum intussuscepts through the ileocaecal valve and into the hindgut creating an elephant trunk appearance.
One or two appendices may be seen on either side of the ileum.
Pubic diastasis is almost twice that seen in children with classic exstrophy and the two phallic halves may be completely separated and asymmetrical with a dominant hemiphallus or hemiscrotum.
Patients with CE almost always required pelvic osteotomies for proper pelvic closure.
The anus is imperforate, sacrum short, and spinal dysraphism may be evident. There is usually an associated omphalocele (>88%) [1].
What are the main operative approaches to anatomic reconstruction?
a. Primary versus staged
b. Early versus delayed.
The author’s surgical preference is the Manchester delayed exstrophy closure technique.
This staged approach involves initial bladder closure with ureteric re-implantation at 3–9 months followed by epispadias repair at 12–18 months.
In this approach, further bladder neck surgery or bladder augmentation may or may not be necessary at 5–6 years depending on continence outcomes and only after vigorous biofeedback training.
The complete primary repair (Mitchell technique) includes bladder closure, urethroplasty, and genital reconstruction. Due to penile ischaemic complications, this technique should be considered obsolete.
However, a modification of the technique with a less aggressive penile dissection is still adopted in some centres in North America.
What are the main components of the staged closure technique?
a. Bladder closure with ureteric re-implantation and tubularisation of the proximal urethra at 3–9 months of age with pelvic osteotomies and insertion of a pelvic external fixator
b. Epispadias repair (12–18 months)
c. Potty training and biofeedback between the age of 3 and 5 years
d. ± Bladder neck reconstruction (~6 years) if continence not attained after bio- feedback training
e. ± Bladder augmentation if small non-compliant high pressure bladder.
What is the sequence of reconstruction in CE patients?
- Initial management of the associated anomalies and prematurity when appro- priate. Severe lung hypoplasia may require prolonged ventilation after birth and occasionally can be fatal.
- If a large omphalocele is present, gradual reduction of the omphalocele is performed in the NICU suspending the umbilical cord to the roof of the incubator to facilitate the descend of the liver into the abdominal wall.
- First stage of reconstruction is performed when the baby is stable, usually in the first few weeks of life:
a. Insertion of central line for parenteral nutrition (PN)
b. Laparotomy with Ladd’s procedure if required
c. Separation of the cecum from the hemi-bladders, tubularisation of the cecum
after washout of the atretic colon and formation of an ileostomy
d. The two hemi-bladders are sutured together
e. The omphalocele is reduced when possible. - Bladder closure with para-exstrophy skin flaps to reconstruct the absent urethra with pelvic osteotomies is performed when the patients is about 6–7 kg.
What are the advantages of performing pelvic osteotomies at the time of initial bladder closure?
• Facilitates closure of the pubic symphysis
• Decreased abdominal wall tension and reduced risk of wound dehiscence
• Placement of bladder and urethra deep within the pelvis
• Increased pelvic floor support around the bladder neck which may improve
future continence.
Studies have shown that exstrophy patients tend to have shorter pubic bones than controls [7].
Although this was originally been thought to be a congenital phenomenon, recent evidence shows that this is an acquired condition resulting from the lack of tension across epiphyseal plates in an incomplete pelvic ring and epiphyseal plate damage following osteotomy [7].
Tension across epiphyseal plates has been shown to increase bone growth [7].
Incision of what anatomic structure is essential to move the bladder and urethra posteriorly in the pelvis?
• The intersymphyseal bands: This structure represents part of the anterior detrusor abnormally attached to the medial portion of the pubic bones.
Failure to divide the intersympheseal bands does not allow positioning of the bladder deep in the pelvis and appropriate securement of the pubic bones in the midline.
What is the most common complication following exstrophy closure?
The most commonly reported complication is a urethrocutaneous fistula (5–40%), commonly in the peno-pubic angle in males [2].
Since they may close spontaneously, they can initially be managed conservatively via catheter drainage.
If the fistula does not close, cystoscopy must be performed to evaluate for possible bladder neck obstruction.
Wound dehiscence is associated with increased tension on the wound and may be reduced with pelvic osteotomies.
Complete breakdown of the repair is rare and usually associated with severe infection or technical errors.
What is the incidence of vesico-ureteric reflux (VUR) following exstrophy closure?
Small bladder size, increased detrusor pressures, and increased outlet resistance following closure results in VUR in almost all patients.
Moreover, the ureters often enter the bladder with a short submucosal tunnel predisposing to reflux.
For this reason, the authors prefer to perform ureteric reimplantations in all patients at the time of primary bladder closure.
Following closure, patients must be followed closely with 3–6 monthly ultrasound scans to look for any signs of upper tract deterioration.
Progressive dilatation, especially when associated with urinary tract infections, may require a period of anticholinergics, intermittent catheterization and eventual bladder augmentation to reduce bladder pressures and protect the upper tracts.
A 35-year old woman born with classic bladder exstrophy underwent a ureterosigmoidostomy in childhood for urinary diversion. What are the long-term complications of this procedure?
Continent and incontinent urinary diversion techniques (i.e. Indiana pouch, uret- erosigmoidostomy, ileal conduit) have largely been abandoned in favour of anatomic reconstruction.
However, these procedures may be useful to achieve dryness in patients who have failed multiple attempts at anatomic reconstruction.
Long-term complications associated with ureterosigmoidostomy [2]:
- Hyperchloremic metabolic acidosis
- Chronic pyelonephritis
- Bladder calculi
- 250–300-fold increased risk of adenocarcinoma at the anastomosis.
Any attempt at reversal of a ureterosigmoidostomy must include excision of a cuff of normal colonic tissue at the site of the implanted ureters to prevent future malignancy [2].
A concerned mother asks you about her daughter’s fertility poten- tial after undergoing a successful staged exstrophy closure. How do you respond?
In contrast to males, most females have normal fertility [8].
Women must have an elective caesarean section to avoid injury to the reconstructed urinary tract.
In addition, females often have normal sexual desire, are adequately sexually active, and have normal menstruations [8].
However, the vagina is often short and verti- cally lying, which may require an introitoplasty or vaginoplasty in adulthood to allow normal sexual intercourse.
Uterine prolapse is a common occurrence (30– 60%) and may be precipitated by pregnancy [8].
In cases of refractory prolapse, complex uro-gyne reconstruction may be required.
In males, fertility potential is significantly reduced and normal sperm counts are reported in 16–63% of patients [8].
The volume of ejaculate of often low and up to 50% experience retrograde ejaculation [8].
The effect on fertility potential is likely attributed to previous bladder neck surgery.
Although the penile length is short, most male patients have normal libido and erections adequate for sexual function [8].
What are the psychosocial outcomes following exstrophy closure?
Both males and females suffer from psychosocial disturbances due to body image and genital perception.
Exstrophy patients have higher rates of anxiety, depression, and suicidal ideation than controls [8].
Therefore, early psychiatric assessment and parental education is warranted.
What is the exstrophy-epispadias complex (EEC)?
The exstrophy–epispadias complex (EEC) is a spectrum of embryologic abnormalities.
Diagnoses within the EEC range in severity from those involving only one organ to others that are a part of a larger complex of defects. The spectrum includes:
□ Epispadias—the urethra is a partial or completely open “plate” dorsally on the penis or between the clitoral halves in a girl.
□ Classic bladder exstrophy (BE)—the urinary bladder is an open plate on the lower abdomen, always associated with epispadias.
□ Cloacal exstrophy (CE)—in which the bladder and the ileocecal junction of the bowel are an open plate on the lower abdomen, and the hindgut is truncated and terminates in the perineum. This condition is also known as the omphalocele/exstrophy/imperforate anus/spinal defect (OEIS) complex.
□ Exstrophy variants—in which partial manifestations of the above anomalies are seen and commonly lack symmetry in the sagittal plane.
H&A
What are common alterations in the anatomy of patients with bladder exstrophy?
Classic BE occurs in approximately one per 50,000 live births, with about an equal incidence in males and females.
CE is rarer with an incidence of 1 in 300,000.
Since the 19th century, various efforts to manage BE have been described.
Because the condition is rare, these approaches were empiric and usually unsuccessful. Until the 20th century, there was no effective surgical approach.
Even now, optimal management is elusive and surgical reconstruction may require multiple operations.
Children with BE typically have an anteriorly located anus.
Also, the female genital anatomy is altered with a more vertically oriented vaginal opening following repair, and a wider and shorter vagina than normal.
The anterior component of the penis is also foreshortened in males compared with the general population.
Classic BE, however, is rarely associated with other organ system malformation.
H&A
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In general infants with bladder exstrophy are born full term, without coexisting anatomic anomalies.
At birth, an everted posterior bladder plate of varying size is seen in the midline of the lower abdomen. The mucosa of the exposed bladder in the newborn is typically smooth and pink.
The umbilical cord exits from the superior-most border of the bladder plate, and a small umbilical hernia may be present.
In addition, there is significant widening of the pubic symphysis and the anus is anteriorly displaced.
The levator ani complex is also divergent, leading to an inherent weakness in the pelvic floor and a tendency toward rectal prolapse and varying degrees of fecal incontinence.
Associated inguinal hernias are common and have been reported in 82% of boys and 10% of girls.
The upper urinary tract is usually normal, though renal anomalies including ectopic, horseshoe, hypoplastic, dysplastic kidneys, and megaureters may be observed.
Vesicoureteral reflux occurs in the vast majority of children after bladder closure, secondary to an exaggerated lateral course of the ureters within the pelvis and lack of adequate submucosal tunnel in the bladder wall.
With continued exposure and chronic inflammation, the exstrophied bladder becomes thickened and polypoid. Long-term exposure may eventually result in a fibrotic, rigid bladder plate that is ultimately unsuitable for closure.
GENITAL DEFECTS—MALE
In the male infant, the open and everted urethral plate can be seen joining the exposed bladder.
The penis is characteristically short with a flattened, everted glans.
The prepuce is located on the penile ventrum.
The ejaculatory ducts are typically normal and exit at the exposed verumontanum in the posterior urethra.
The base of the penis and scrotum are widely separated, with lateral displacement of the corporal bodies and neurovascular bundles.
Historically it was believed that the individual corpora were of normal caliber and appeared shortened because of their attachment to the widened pubic diastasis and associated dorsal chordee.
More recently, an MRI-based study by Silver and colleagues of adult men with exstrophy and age-matched controls found that although the length of the posterior corporal bodies was the same between groups, anterior corporal length in men with exstrophy was nearly 50% shorter than that of controls.
Therefore the penis appears shortened not only secondary to corporal divergence, dorsal chordee, and abnormal crural attachments to the corpora cavernosa, but also because of an inherent deficiency of corporal tissue.
The testes may appear to be undescended, but in most cases they are actually retractile and will eventually reside in the scrotum without the need for formal orchiopexy.
Should it be required, orchiopexy is performed in conjunction with inguinal hernia repair.
GENITAL DEFECTS—FEMALE
The clitoris is bifid, with divergence of the mons pubis, labia, and clitoral halves.
The urethra and vagina are shortened, and the introitus is anteriorly displaced.
The vaginal orifice is often stenotic.
The uterus and adnexa are typically normal, though vaginal and uterine duplication have been reported.
Uterine prolapse occurs commonly in female patients, secondary to the inherent weakness in pelvic floor support.
PELVIC DEFECTS
Some degree of widening of the pubic symphysis is present in all cases of bladder exstrophy and contributes to outward rotation and eversion of the pubic rami at their junctions with the ischial and iliac bones.
Using computed tomography (CT), Sponseller and colleagues further characterized the pelvic anatomy of a large group of exstrophy patients, noting a significantly increased distance between the triradiate cartilages (31%), external rotation of the anterior pelvis (18%), and 30% shortening of the pubic rami.
On the basis of three-dimensional models generated by CT, Stec and colleagues observed that among children with exstrophy, the levator ani muscles were more posteriorly positioned and outwardly rotated.
Furthermore, the puborectal sling had a more flattened configuration and supported twice the body cavity area in exstrophy patients.
As mentioned previously, these pelvic floor defects predispose to pelvic organ and rectal prolapse in this patient population.
Coran
What are typical antenatal ultrasound findings for bladder exstrophy?
BE can be diagnosed antenatally, although many affected fetuses are not identified until birth.
Ultrasound (US) can usually detect BE before the twentieth week of gestation by noting an absence of the urinary bladder as a fluid-filled structure within the fetal pelvis.
Other US findings include:
□ A semisolid mass protruding from the abdominal wall
□ A lower abdominal protrusion
□ An anteriorly displaced scrotum with a small phallus in male fetuses
□ Normal kidneys in association with a low-set umbilical cord
□ An abnormal iliac crest widening
Findings such as low umbilical cord insertion and the location of the genitalia will be seen only if the fetus is examined in the sagittal plane.
The iliac angle will be about 110° rather than the usual 90°.
Since kidneys and urine production are typically normal in these fetuses, amniotic fluid levels are usually normal.
Any abnormalities seen on US should prompt a fetal magnetic resonance imaging (MRI) scan, which provides better visualization and the ability to characterize the exstrophy or variant, and distinguish exstrophy from other abdominal wall defects.
Prenatal diagnosis helps provide for prenatal counseling, optimal perinatal management, and the chance to be delivered near a pediatric center where skilled newborn care is available to treat these babies. This counseling should include the expertise of a fellowship trained pediatric urologist experienced in the care of children with exstrophy.
H&A
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The use of prenatal ultrasound (US) and MRI has improved the antenatal diagnosis of bladder exstrophy, allowing for appropriate parental counseling and planning of postnatal management.
The prenatal diagnosis of bladder exstrophy may be suggested on US by failure to visualize the bladder in the presence of normal kidneys and amniotic fluid.
In a review of prenatal US studies from 25 women who delivered infants with exstrophy, Gearhart and colleagues observed the following features:
absent bladder (71%),
lower abdominal bulge (47%) and
anteriorly displaced scrotum with small phallus in male fetuses (57%),
low-set umbilical cord (29%), and
abnormal widening of the iliac crest (18%).
Coran
What is the embryology and pathogenesis of bladder exstrophy?
Experts disagree on the embryologic explanation for the development of BE. In the prescientific era, the cause of BE was attributed to trauma to the unborn child causing ulceration of the abdominal wall with subsequent bladder herniation.
Today, we know that the developing human embryo does not normally pass through a stage that corresponds to exstrophy.
This knowledge excludes an arrest in development as a possible etiology and implicates an error in embryogenesis involving the cloacal membrane.
The mesodermal membrane folds to form and separate the coelomic cavity from the amniotic space late in the third week of development.
The intermediate layer of this mesoderm forms the urogenital system.
Disruption in this part of the membrane is thought to lead to EEC.
4 - 5 weeks AOG: Normally by the fifth week, the mesoderm has formed lateral folds that tubularize into the gut tube and cloaca.
However, if the mesenchymal cells do not migrate appropriately during the fourth week of development, then EEC can develop.
The actual reason why the intermediate mesoderm does not migrate appropriately to separate the cavities and form the abdominal wall is not known. Several hypotheses have been raised, including:
- physical obstruction of the mesodermal migration,
- premature rupture of the cloacal membrane, and
- cellular dysfunction that limits migration of the mesoderm.
To explore the theory that early disruption of the cloacal membrane results in diagnoses within the EEC, a model of CE in the developing chick embryo was created by using a CO2 laser to create an early dehiscence in the tail bud caudal to the omphalomesenteric vessels.
This model suggested that exstrophy may result from failure of the mesodermal ingrowth between the ectoderm and endoderm of the cloacal membrane, which then later ruptures prematurely.
It is hypothesized that such an event could be caused by early hypoxemic infarction in the region of the tail bud followed by subsequent cellular loss of the mesoderm and herniation of the developing bladder or cloaca.
This type of ischemic injury has also been implicated as the cause of gastroschisis and could explain the EEC spectrum.
Another possible mechanism resulting in a similar pathophysiology could be a defect in a genetic switch that results in premature senescence of the infraumbilical membrane (analogous to an ischemic injury). This hypothesis implies an epigenetic basis for exstrophy.
Animal models to study BE have been difficult to create. In a BE sheep model, a significant increase in the ratio of collagen-to-smooth muscle was noted in exstrophic versus normal control bladders (P < 0.05). These histologic changes in the ratio of collagen to smooth muscle content are similar to changes seen in human BE specimens.
Recently a genetic murine model of BE was created using p63 knockout mice that phenotypically demonstrated the complete spectrum of BE, including exstrophy, epispadias, separation of pubic bones, as well as imperforate anus and exomphalos. This model, combined with previously demonstrated mesenchymal-epithelial signaling, is leading to further hypotheses of the pathways involved in the development of BE.
While historically BE had been thought to be potentially due to environmental exposure or even an infectious pathogen, the exact underlying cause of exstrophy remains in question.
There is clearly a genetic component. Siblings of children with BE have an incidence of BE that ranges from 0.3–2.3%, much higher than normal. The incidence in children in whom one parent had exstrophy has been reported to be 1.4%, or 400-fold higher than the general population. However, the numbers on which these statistics are based are small. Only 37 familial cases of BE have been reported, the most recent of which describes a mother and son with BE. Four other cases of an affected parent–child pair have also been described. Another 18 cases with BE have been found in twins.
Prenatal counselors estimate the risk of recurrence in a sibling of a patient with exstrophy at about 1% with a 1:70 chance of transmission to the progeny of an affected parent.
A Florida population-based study found multiple births had a 46% increased risk of birth defects, with BE being the fifth highest adjusted relative risk.
These findings support a multifactorial etiology with evidence for genetic predisposition.
More recently, an epidemiologic survey of families with BE found no link between exstrophy and parental age, maternal reproductive history, or periconceptional maternal exposure to alcohol, drugs, chemical noxae, radiation, or infections.
Periconceptional maternal exposure to smoking has been noted to be significantly more common in patients with EEC.
Specific genes and copy number variants (CNVs) have been potentially associated with BE. A recent genome wide association study has implicated a gene (ISL-1) on chromosome 5q11.1, which may be a susceptibility gene for BE.
However, in other studies, evaluation of CNVs showed that single genomic CNV are unlikely to be the cause of BE, although this cannot be completely excluded.
Whole exome sequencing and genome wide association studies are in progress to begin to identify candidate genes that may contribute to the likely multifactorial etiology of BE.
H&A
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The underlying embryologic defect shared by bladder exstrophy and other variants of the EEC is due to abnormal development of the cloacal membrane, a bilaminar structure composed of endoderm and ectoderm that overlies the cloacal cavity at the caudal end of the germinal disk.
In normal development, lateral ingrowth of mesoderm occurs between the two layers of the cloacal membrane during the fourth and fifth weeks of gestation.
This results in formation of the lower abdominal wall and pelvis.
Subsequent caudal growth of the urorectal septum results in its fusion with the cloacal membrane, thus fully separating the cloaca into the bladder anteriorly and the rectum posteriorly.
The paired genital tubercles, which will give rise to the phallus, migrate medially to fuse in the midline.
Normal perforation of the cloacal membrane occurs after fusion with the urorectal septum, at approximately the sixth week, resulting in formation of separate urogenital and anal openings.
Migratory failure of the lateral mesodermal folds and abnormal overdevelopment of the cloacal membrane have both been proposed as potential causes of the prevention of normal mesodermal ingrowth to the cloacal membrane.
The lack of adequate mesodermal reinforcement is thought to result in premature rupture of the cloacal membrane, the timing of which determines the extent of the abdominal wall defect and degree/severity of urogenital tract involvement.
Rupture of the cloacal membrane after fusion with the urorectal septum results in bladder exstrophy, whereas rupture before fusion gives rise to the more severe presentation of cloacal exstrophy.
Coran
What are the goals of reconstruction in bladder exstrophy repair?
The initial goals of BE repair are to close the bladder and urethra, and to reconstruct the genitalia in order to create functional organs for continence, voiding, and sex.
By achieving a successful primary repair, the bladder can cycle and grow in capacity and can provide safe storage under low pressure.
The goal of closure is also to create a competent bladder neck that can coapt to provide continence, and also can relax to allow a sustained detrusor contraction, resulting in normal voiding with complete emptying.
Achieving normal bladder storage and emptying minimizes the risk of upper urinary tract deterioration, prevents urinary tract infections (UTIs) and vesicoureteral reflux (VUR), and decreases the risk of urinary calculi.
A wide range of operations have been developed to repair BE.
These can be grouped as (1) urinary diversion or (2) anatomic reconstruction.
Anatomic reconstructions include single and multistaged repairs with progressive degrees of delayed reconstruction.
Surgeon preference and experience, patient anatomy, history of previous operations, availability of tertiary care facilities, and access to medical care and resources all play a role in choosing a specific operative procedure for a particular patient.
H&A
What are expected outcomes of bladder exstrophy without treatment?
Children with BE can survive untreated.
However, significant morbidity can include skin breakdown secondary to total urinary incontinence, tumor development within the chronically exposed bladder plate, and significant psychosocial morbidity.
In contrast, when these patients receive effective surgical and medical treatment, they can lead productive, healthy lives with minimal and manageable morbidity.
Very early efforts in BE management were directed at partial reconstruction of the abdominal wall to allow the application of a urinary receptacle to collect urine.
Early attempts at closing the bladder were fraught with complications, which led to urinary diversion through the creation of ureterosigmoidostomies (USO) with equally poor results.
It was only with a progressive understanding of urinary tract and bladder physiology, the effect of BE repair on urine storage and emptying, and the concept of clean intermittent catheterization (CIC) that the management has evolved to its current manageable, yet imperfect state.
H&A
What are indications and options for urinary diversion for bladder exstrophy?
Primary urinary diversion is not commonly performed in the United States or in most of Europe. Urinary diversion has largely been abandoned in favor of primary bladder closure.
However, continent urinary diversion approaches produce a more consistent degree of dryness with fewer required operations and fewer early complications than that achieved with anatomic reconstruction.
Techniques for constructing urinary diversions are listed in Table 58.1.
Continent diversions can be completely internalized and rely on the rectal sphincter complex, or can be partially externalized, requiring catheterization of a continent stoma.
Incontinent diversion can also be employed. Incontinent diversion avoids the complications associated with continent reconstruction such as a failed continence mechanism resulting in persistent incontinence, urinary retention, stomal complications, and dependence on CIC to empty the bladder.
Diversion can be combined with cosmetic and functional reconstructive procedures for the external genitalia.
Because of the difficulties encountered with functional bladder reconstruction, especially in resource poor settings, early urinary diversion advocates argue that diversion achieves the primary goals of dryness with fewer operations and higher success rates than are achieved with bladder closure and urethral reconstruction.
One of the earliest forms of diversion used in BE reconstruction was the ureterosigmoidostomy (USO). However, this diversion allows the high pressure of the contractile sigmoid to reflux infected urine or feces back into the urinary system resulting in severe infections.
Long-term complications includes hyperchloremic metabolic acidosis, chronic pyelonephritis, bladder calculi, and a 250- to 300-fold increased risk of adenocarcinoma developing at the anastomosis of the ureter(s) to the colon.
As a result of these complications, USO was replaced by incontinent urinary diversions such as colonic and ileal conduits.
A significant disadvantage to these conduits is the associated incontinent abdominal stoma and the need for a receptacle/appliance as well as a high rate of bowel segment stenosis/obstruction and infection.
The Mainz II pouch (a detubularized sigmoid pouch) provided a significant improvement to the USO.
This detubularized pouch reduces reservoir and ureteral pressures, and improves nighttime continence.
In one study, renal preservation rates in children treated primarily with a urinary rectal reservoir (Mainz II pouch) approached 92% with continence rates up to 97%.
The Heitz–Boyer–Hovelacque procedure involves isolation of a rectal segment for ureteral implantation followed by posterior sagittal pull-through of the sigmoid colon through the anal sphincter.
A small series using this approach reported continence rates of 95% with an acceptable complication rate.
A recent long-term evaluation of patients treated with continent anal urinary diversion (CAD) found a 97% daytime urinary continence rate and a 65% nighttime continence rate with minimal urine loss during sleep or sexual activity.
An alternative rectosigmoid bladder reservoir was recently evaluated for continence. This approach was used both for primary treatment and salvage repairs. Complete rectal continence was only 52% in this cohort, while the remainder had leakage during passage of flatus or abdominal straining.
Frequent bladder emptying can reduce the risk of metabolic electrolyte imbalances since frequent emptying of the rectal reservoir reduces the contact time between the urine and the absorptive rectal mucosa.
The standard treatment of metabolic acidosis is with oral bicarbonate replacement.
While reconfiguration of the pouch and frequent emptying may reduce the risk of infection and wetting, the risk of malignancy still remains a concern.
Various modifications of the rectal reservoir to prevent admixture of feces and urine may decrease the incidence of cancer. In a 45-year experience with CAD, Rubenwolf reported 8/82 patients developed neoplasms, most often at the ureterointestinal anastomosis. Four of these patients died shortly after diagnosis, while the remainder were managed with resection and revision of the diversion.
H&A
What is the difference between the two modern approaches for anatomic reconstruction of bladder exstrophy— CPRE and MSRE?
The first efforts at anatomic reconstruction for BE were unsuccessful but set the stage for the current anatomic approach.
In 1881, Trendelenberg described an exstrophy closure emphasizing the importance of pubic reapproximation in front of the reconstructed bladder in order to achieve continence and prevent dehiscence.
However, because of discouraging results, anatomic reconstruction was largely replaced by urinary diversion in the early part of the 20th century. In the latter half of the 20th century, there were several series of patients who underwent single-stage reconstruction, with most reporting continence rates of 10–30%. The most concerning complication was the high incidence of renal damage, reported as high as 90% in generally secondary to bladder outlet obstruction.
As a result of devastating upper tract damage and the low rate of urinary continence with single-stage approaches, reconstructive efforts were modified toward staged bladder reconstruction. This approach was pioneered in the 1970s and further refined to what is now known as the modern staged repair of exstrophy (MSRE).
Later advances in single-stage reconstruction, combined with the advent of CIC, led to a resurgence of this approach and the development of the complete primary repair for exstrophy (CPRE), which has now developed alongside the MRSE.
The primary goal of both approaches is to reconstruct the abdomen and genitalia to achieve anatomic and functional normalcy with minimal operative morbidity.
Reconstruction of the newborn female with BE is similar in both the CPRE and MSRE techniques with the end result being closure of the bladder, urethra, and abdominal wall.
For the CPRE technique, the main difference is a more aggressive mobilization of the vagina and urethral plate posteriorly into the pelvic diaphragm in order to gain bladder outlet resistance that allows for normal voiding with continence rather than the need for later bladder neck reconstruction (BNR), as is the case for MSRE.
In contrast, closure of the male with BE is quite different in the CPRE and MSRE techniques. The CPRE closes and repositions the bladder and entire urethra in one surgical procedure.
In contrast, the MSRE closes and repositions the bladder and posterior urethra at the first stage with the remainder of the urethra closed (epispadias repair) at a later stage, followed by BNR as the last stage.
H&A
What is the best timing of repair for bladder exstrophy?
Traditionally, primary BE closure was performed in the immediate newborn period, prior to 72 hours of life.
This potentially allows for anatomic closure without the use of osteotomies and reduces the time of bladder exposure.
McMahon and colleagues feel there are definite advantages to immediate postnatal exstrophy closure, reporting that infants closed before 7 days of age required fewer bladder augmentations, while continence rates were the same in their early or delayed closure group.
Another study reported that closure of infants <72 hours old with a pubic diastasis <4 cm and without osteotomy has the same failure rates as those performed with osteotomy.
In the past, proponents of early closure pointed to decreasing bladder exposure that can lead to histologic changes such as acute and chronic inflammation, squamous metaplasia, cystitis glandularis and cystitis cystica, and muscular fibrosis, which may adversely impact bladder capacity and compliance.
A recent study showed that primary polyps did not change outcomes in bladders closed early or later.
Other early studies of the anatomy and physiology of the newborn exstrophy bladder showing an “immature” physiology with fewer and smaller nerve fibers and less smooth muscle have helped to theorize that early closure could help to “mature” the bladder with bladder cycling.
H&A
What are perioperative adjuncts to successful bladder exstrophy closure?
Preoperative
After delivery, to reduce trauma to the bladder plate, the umbilical cord should be ligated with suture rather than a plastic or metal clamp.
A hydrated gel dressing or plastic wrap can be used to protect the exposed bladder from superficial trauma from a diaper.
The baby should undergo an US to evaluate the kidneys and to establish a baseline examination for later US studies, as well as an anteriorposterior radiograph of the pelvis to assess the degree of pubic diastasis.
Preoperative spinal US examination should be considered if sacral dimpling or other signs of spina bifida occulta are noted on physical examination.
Although an associated spinal abnormality is common with CE, it is rare with BE.
If closure is performed beyond the first 72 hours of birth, the baby can be discharged from the hospital with the mother, thus providing time for bonding with the parents.
Preoperative antibiotic prophylaxis is not required. However, perioperative and postoperative antibiotics are used to decrease the risk for infection following reconstruction.
Delayed Primary Closure
Several recent studies have advocated for delayed primary closure, especially in contrast to the CPRE approach, either in primary or failed exstrophy closures.
Proponents of delayed repair argue that it is safer for the child, allows a more coordinated surgical effort, and allows an elective operation so that the most expert team of clinicians and personnel are available.
Delay in closure can allow time for the baby to become more robust and stable, and allows for parental bonding before the child is placed in traction for 4–6 weeks.
Moreover, in an era of the development of high-volume centers, delayed closure allows for consultation and transfer if needed.
A recent study found no difference in the bladder capacity in babies who underwent newborn closure versus closure at 1–9 months of age. Others have similarly shown it is possible to wait months after birth with good results.
Such a delay may be useful to stimulate the penis with testosterone with the goal of reducing the chance for glans injury, and there have been good short-term outcomes reported with this approach in six male infants.
The successful use of a delayed closure approach is predicated on adequate protection of the exposed tissue. However, Nelson et al. found an increased cost of as much as 50% with delayed closure. Long-term outcomes will take years to mature.
Other considerations during general anesthesia include minimizing abdominal distention, which can increase intra-abdominal pressures postoperatively and can lead to compartment syndrome, which may compromise renal function and also increase the risk of wound dehiscence.
Also, nitrous oxide should be avoided, as it can cause bowel distension.
An epidural catheter can decrease the need for narcotics and inhaled anesthetics during the operation, and keeps the baby comfortable postoperatively.
Tunneling the epidural may reduce the risk of infection if it will be used for prolonged time after repair.
Postoperatively, maximal urinary drainage with ureteral stents and a suprapubic tube are critical to divert urine away from the bladder as it heals.
Adjunctive Aspects of the Repair
Indirect inguinal hernias are commonly associated with BE in both boys and girls.
They arise as a consequence of enlarged internal and external inguinal rings combined with compromised fascial support and lack of obliquity of the inguinal canal.
To assess the benefits of preemptive hernia surgery, a single institution recently reviewed its experience with 43 patients with BE. Of the 25 that did not undergo inguinal hernia repair at the time of original closure, 9 needed hernia repair later, while no children who had a hernia repair at the time of BE closure suffered any complications from the repair. Thus, they have advocated for inguinal exploration and repair of an inguinal hernia at the time of exstrophy closure.
Alternatively, Lavien et al. reviewed a series of 136 patients with a history of BE and found that closure with osteotomies decreased the need for hernia repairs.
Due to the high incidence of VUR after exstrophy closure (up to 75%), some surgeons perform ureteral reimplantation at the time of initial closure. The cephalotrigonal reimplantation has been described in patients with bladder exstrophy. This approach implants the ureter in a safe way, accounting for the inferior insertion using an almost right angle into the bladder, thus providing a more gradual course through to the neohiatus, which provides more distance from the bladder neck to the ureteral orifices. Braga et al. also have demonstrated the safety and efficacy of ureteroneocystostomy at the time of initial closure. We have adopted Braga’s approach and perform ureteral reimplantation, particularly in the female, if the bladder plate is adequate.
Osteotomies
Infants with BE have a wide and flattened pelvis that is laterally displaced, thus leaving little support for the genitourinary organs.
There is external rotation of the posterior pelvis, shortening and external rotation of the pubic rami, and a wide pubic diastasis.
Approximation of the externally rotated bony pelvis is critical to decrease tension on the abdominal wall closure, to help to reapproximate the pelvic floor musculature, and to place the bladder and urethra deep within the pelvic diaphragm.
Effective reapproximation of the pubic symphysis decreases the rate of abdominal wall dehiscence and improves rates of continence in children closed outside of the immediate newborn period.
In order to aid in the closure of the pelvis, osteotomies are performed.
Osteotomies offer several advantages when performing the anatomic approach to BE closure including
(1) optimizing pubic symphysis apposition, diminishing tension on the fascial repair;
(2) optimizing placement of the bladder, bladder neck, and urethra in the pelvis;
(3) improving the reapproximation of the corporal and clitoral bodies; and
(4) decreasing the chance for later uterine prolapse.
Traditionally osteotomies have been done for any child >72 hours old, in newborns with an exceptionally wide diastasis, and in reoperative BE closure/repair. However, there are data supporting osteotomies as being valuable even in the first 72 hours.
Osteotomies are usually performed at the same setting as bladder closure to help secure the closure.
Bilateral iliac osteotomies can be performed through either an anterior or posterior approach. Posterior iliac osteotomies are performed with the patient prone, after which the patient is then repositioned for the bladder closure.
Immobilization
After the primary reconstructive procedure for exstrophy, either with or without osteotomy, the patient must be immobilized to decrease stress on the closure.
There are various types of immobilization used, with no one optimal method. Options include
(1) modified Bryant’s traction,
(2) external fixation, or
(3) spica cast.
Each of these has its benefits and drawbacks.
1) Modified Bryant’s traction
Modified Bryant’s traction immobilizes the baby in a bed and the hospital for 4–6 weeks, and the bindings on the legs can cause injury to the skin.
2) External fixation
External fixation also immobilizes the patient but carries a risk of external wound infections along the pin sites.
Therefore, the pin sites require daily cleaning.
In some centers, external pinned fixation is recommended for older children in whom the bones are mature enough to hold a pin.
3) Spica cast
The spica cast allows for more mobility and earlier discharge from the hospital and is associated with decreased length of hospitalization and lower cost.
Another option when using a spica cast is creation of a “window” over the epidural catheter entry site. This facilitates inspection of the site and management of the catheter as needed.
We have moved to using a hinged spica cast, which is easier to remove (only the outer wrap can be cut and then replaced, or the two halves are kept together by Velcro wraps so the skin can be checked daily).
Modified Buck’s traction has also been used by many groups with success.
A posterior lightweight splint can be used in newborns when the child is out of traction to maintain hip adduction.
Internal fixation may be necessary in older patients.
Femoral nerve palsy is a possible complication with fixation that must be monitored and can be reduced by gradually tightening the fixator.
Osteotomies are not a component of the classical Kelly technique.
H&A
What are important elements in the CPRE approach to bladder exstrophy?
CPRE was introduced by Grady and Mitchell in 1998.
This technique includes the combination of bladder closure, anatomic bladder neck narrowing, urethral elongation, and epispadias repair in a single operation in order to provide an environment for bladder cycling.
At times, anatomy permitting, bilateral ureteral reimplantation is performed at CPRE in order to achieve the goals of urinary continence and preservation of renal function.
Timing of the operation, whether or not to use osteotomies, the technique for the osteotomies, postoperative pain management, and postoperative immobilization are all factors to consider.
Important elements of the surgical technique apply, with consideration given to limiting tissue injury, skin hook(s) versus forceps, scissors/knife versus electrocautery, topical dilute epinephrine, fine absorbable suture versus electrocautery (bipolar preferred) for hemostasis, and loupe magnification.
H&A
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Recently, Mitchell and Grady minimized the number of required operations by combining bladder closure with epispadias repair at birth in a technique known as complete primary repair.
Major potential benefits of this approach include the earlier creation of bladder outlet resistance, theoretically leading to normal cycling and improved bladder capacity and functionality as the patient grows.
Major principles of CPRE include total penile disassembly and division of the intersymphyseal band, which enables posterior positioning of the bladder, bladder neck, and urethra.
As described by Grady and Mitchell, CPRE begins with intubation of each ureteral orifice with ureteral catheters.
Traction sutures are placed into each hemiglans, the bladder plate is circumscribed, and dissection is continued inferiorly along the ventral aspect of the penis.
The urethral plate is mobilized off the penis, which is fully disassembled into separate right and left corporal bodies and the spongiosum-containing urethra.
The intersymphyseal band is incised, which allows the bladder unit to be positioned deep within the pelvis.
A suprapubic tube is left in place, the ureteral catheters are externalized, and the bladder is closed.
Similar to the staged approach, pelvic osteotomy may be required for abdominal closure.
The pubic symphysis is approximated using PDS sutures, and the abdominal wall is closed.
The urethral plate is tubularized and transposed to the penile ventrum, and the corporal bodies are rotated medially and reapproximated.
Because of the new posterior positioning of the bladder unit, urethral length is often inadequate to reach the glans, and a hypospadiac meatus is left for future reconstruction.
Penile shaft coverage is achieved through the use of ventral rotational penile skin flaps.
Postoperatively, the patient remains immobilized as previously described in the technique of staged closure.
Additional procedures to correct for residual hypospadias, vesicoureteral reflux, and incontinence may be required as the child grows.
Coran
How is the CPRE technique performed in a boy with bladder exstrophy?
1) Preparation and Assessment of the Anatomy
Total body preparation is performed. Bilateral iliac osteotomies are completed prior to sterile prep if a posterior approach is used, or after prepping if an anterior approach is chosen. The anatomy should be evaluated at the outset of the procedure.
Tegaderm (3M) is placed over the anus. A stay suture is placed transversely in each hemiglans of the penis. Measurements of the bladder and urethral plate are recorded.
Identifying and lightly marking the verumontanum and ureteral orifices facilitates orientation and assessment of dimensions, and clarifies important landmarks.
Each ureteral orifice should be intubated with a small caliber feeding tube and secured with an absorbable suture.
Assessing the bladder surface for polyps, with excision of large polyps as well as those near a ureteral orifice or at the bladder neck to eliminate irregularity, should be performed as this often facilitates bladder closure. Depending on the size of the polyp, approximation of tissues and hemostasis at the base of the polyp is achieved with a running absorbable suture.
Pubic bones are marked bilaterally, and incision lines are marked at the perimeter of the bladder, bladder neck, and urethral plate.
The future neoumbilicus site is also marked in the infant’s midline at the level of the iliac crest.
The umbilical stump or scar is incorporated with the bladder via an inverted “V” incision marked at the cephalad extent of the skin incision caudal to the neoumbilicus. This tissue will eventually be discarded but functions nicely as a handle during dissection. Also, the incision planned in this manner will promote cosmesis at the time of closure.
Initial dissection of the bladder, penis, and urethral plate then follows:
2) Initial Incision and Delineation of Planes
The incision begins at the cephalad extent of the defect (where the inverted “V” is marked) and is carried along the perimeter of the bladder and urethral plate using fine needle point electrocautery.
The incision is deepened at its cephalad extent, and care is taken to identify, isolate, and ligate the obliterated umbilical arteries and vein.
The peritoneum is carefully separated with sharp and blunt dissection from the external surface of the bladder dome, and the posterior and lateral walls.
A traction suture is placed in the umbilical stump/scar to facilitate dissection.
In order to identify the often difficult plane between the bladder wall and the rectus muscle and fascia, one can first identify the plane between the skin and the anterior surface of the anterior rectus fascia.
The dissection is carried along the anterior surface of the fascia, exploiting the “fat is your friend” concept in developing this important plane. In the thin infant with a paucity of abdominal wall fat, beginning this dissection at the level of the pubic bones, where typically a fat layer exists, and progressing in a cephalad direction, may be helpful.
Accurately identifying this initial plane, and thus the medial edge of the anterior rectus fascia, facilitates accurate identification and dissection of the plane between the medial and posterior aspects of abdominal wall/rectus fascia and bladder edge.
Adherent rectus and detrusor muscle fibers can be distinguished by the longitudinal course of the rectus component.
Continued dissection along the perimeter of the bladder is facilitated by inserting the (right-handed) surgeon’s left index finger inside the bladder and inverting it. This allows better appreciation of the correct plane of dissection.
3) Intersymphyseal Bands
The dissection, as described earlier coursing caudally along the lateral aspects of the bladder wall, will eventually lead to the intersymphyseal band attachments that tether and displace the bladder trigone and bladder neck anteriorly.
As the dissection progresses and tissue permits, blunt dissection along the lateral bladder wall will exploit the plane by identifying and entering the perivesical fat plane. This facilitates “pushing” of the distal aspect of the bladder medially and creates space underneath the intersymphyseal band on either side of the bladder neck.
Using the medial edge of the pubic bone as a reference, the intersymphyseal bands are now divided. This is perhaps the most important part of the operation as it will allow appropriate placement of the bladder, bladder neck, and posterior urethra deep in the pelvis.
This can be continued in a caudal to cephalad direction following urethral plate dissection.
4) Urethral Plate Dissection
This step is optimized via an initial ventral approach.
Preputial skin adhesions to the glans are released, and the skin incision is marked ventrally parallel to the corona.
The penile shaft is degloved of its skin.
At the lateral aspects of this dissection, care is taken to avoid injury to the corpora and neurovascular bundle (NVB) as these structures are often adherent to the thin skin in this area.
The ventral approach continues along the medial aspect of the corpora cavernosa using sharp dissection and bipolar electrocautery in order to develop this plane, allowing both hemostasis and preservation of the blood supply to the urethra.
Visualization and dissection of this plane is facilitated for the right-handed surgeon positioned on the patient’s right by applying gentle lifting pressure with the left index finger underneath the dorsally reflected penis.
This technique turns both corpora cavernosa laterally and elevates the corpus spongiosum/ ventral urethral plate.
This dissection proceeds proximally to the penoscrotal junction where the corpora separate.
The dorsal urethral dissection begins with scissors at the lateral edge near the longitudinal midpoint of the urethral plate. The sharp dissection is medial and parallel to the neurovascular bundle.
Dissection is carried medially alternating from dorsal to ventral until the corpora begin to be separated from the urethral plate, usually at the midpoint of the dissection.
At this point, the surgeon passes a vessel loop between the corporal body and the urethral plate.
The urethral plate dissection continues proximally toward the bladder neck and distally toward glans.
The vessel loop gently reflects the urethral plate away from the midline.
In a modification of the complete penile disassembly technique, the glans is instead kept in continuity, which seems to reduce the risk of venous stasis and glanular ischemia in the first few postoperative hours.
In the absence of dorsal “bowing” secondary to a short urethral plate, the urethra is kept in continuity with the glans in order to preserve the urethral plate vascular communication and symmetry.
A urethral width of approximately 15 mm is maintained throughout the entire length of the dissection all the way to the bladder neck.
If the urethral plate is short and the “bowing” effect is enough to compromise penile length, the distal urethra can be detached from the glans as long as the left and right hemiglans remain intact.
5) Deep Dissection
The dissection now proceeds proximal and medial to the NVB to the level of the prostatic urethra and bladder neck.
This allows for maximal extension of the corpora and permits the bladder neck to be rolled in the midline under little or no tension.
Eventual approximation of these structures will also be facilitated by iliac osteotomies and the subsequent bony pelvic closure.
Therefore, dissection on either side of the bladder neck should be limited to what is necessary to provide a tension-free anastomosis.
Careful attention is necessary when using the bipolar electrocautery for hemostasis to prevent the current from traveling along the corpora or NVB (or both).
6) Elongation of the Urethra/Bladder Neck
Development In order to provide near normal urethral anatomy after the operation, the width of the urethral plate is maintained cranially before it widens at or just proximal to the bladder neck.
The level of the bladder neck is identified between the verumontanum and the ureteral orifices by the appearance of ridges or folds in the urothelium that run in a longitudinal orientation.
We mark the proposed incision sites for the BNR with 5-0 prolene stay sutures.
The bladder neck width is typically marked out to be 2–3 mm wider than the urethral plate width, which is approximately 15 mm.
The excess width at the bladder neck is deepithelialized, and the excess detrusor is either resected or incorporated into the closure.
7) Approximation of Tissues (Tubularization of Neourethra, Bladder Neck Approximation, Bladder Closure) Urethra
The urethral meatus can be advanced as needed with a midline longitudinal incision of the glans followed by transverse approximation (Heineke–Mikulicz technique) using fine absorbable interrupted sutures.
The urethroplasty (tubularization of the urethral plate) begins at the meatus over the ureteral catheters (unless the ureters are reimplanted at the time of complete closure) using imbricating interrupted sutures in order to invert the mucosa to decrease the risk of fistula (the needle trajectory should invert the mucosa).
Interrupted sutures are placed and then tied in order to provide clear and precise visualization of the urethral plate edge. 6-0 Polydioxanone (PDS) or polyglyconate (Maxon) suture is used for the distal urethra, 5-0 PDS or Maxon for the mid-proximal urethra, and 4-0 PDS or Maxon for the proximal urethrabladder neck.
After placing the first sutures distally to begin the urethroplasty, several sutures are inserted at the level of the bladder neck.
This serves several purposes as it takes some tension off of the urethral approximating sutures, provides clear delineation of this important anatomic landmark, and aids in achieving a symmetric urethroplasty.
8) Bladder neck and Bladder.
The bladder neck and bladder are approximated with interrupted 4-0 PDS sutures.
Placement of one suture at the apex of the bladder dome facilitates closure.
The umbilical stump or scar should be excised, along with any grossly epithelialized bladder mucosa, prior to approximation at the bladder dome.
A suprapubic cystostomy tube is passed through the neoumbilical site and into the bladder at a separate site lateral and/ or cephalad to the apex of the bladder closure.
9) Pubic Bone Approximation.
The subcutaneous tissue is elevated off the anterior surface of the pubic bones bilaterally in order to clearly identify these structures and facilitate accurate placement of the sutures.
The pubic bone is approximated with horizontal mattress and simple interrupted sutures using #1 or 0 PDS.
Manual approximation of the pubic bones is maintained while tying these sutures.
10) Corpora Cavernosa Approximation and Glansplasty
The corpora cavernosa and glans are examined carefully for any evidence of impaired blood flow or frank ischemia.
Trimming of the lateral edges of each hemiglans and observing for expected bleeding is an important step.
If the blood flow is compromised, the sutures approximating the pubis are immediately released and replaced with less tension to prevent ischemia to the glans.
As long as blood flow continues, the penile reconstruction resumes with closure of the urethra and glans.
Subcutaneous simple interrupted sutures approximate the glans in the midline.
Depending on the need to address any dorsal penile curvature, several interrupted or horizontal 4-0 PDS mattress sutures are ernosa.
External rotation of the corpora proximally, with gentle internal rotation distally at the level of the glans, may avoid any later dorsal curvature.
11) Abdominal Wall Closure
The rectus muscle and fascia are approximated in two layers with running 2-0 PDS.
The typical transverse lower abdominal skin crease is an important landmark to guide symmetric approximation of the abdominal wall subcutaneous and deep dermal tissues.
A subcuticular skin closure is then performed.
12) Penile shaft skin coverage.
The penile shaft is covered with one of several techniques such as reverse Byars skin flaps, depending on tissue availability.
A primary dorsal closure is usually not possible.
Byars flaps can be used, but this technique leaves a dorsal scar.
A flap described by Pippi Salle and colleagues can be used to rotate the ventral shaft skin 90° on a pedical, thus placing the seam on the lateral aspect of the penis.
Tacking sutures can be placed to prevent the penile shaft skin from riding over the corporal bodies and “burying” the penis.
13) Umbilicoplasty
There are several options for umbilicoplasty.
A same site, full-thickness skin graft can be used for umbilicoplasty. With this technique, a circle of skin is marked, excised, and completely defatted. A “core” of subcutaneous tissue and fat deep to the circular graft is excised down to the level of fascia. The defatted circle of skin is then tacked back down to the fascia. This area also serves as the exit site of suprapubic tube.
Alternatively, a rhomboid flap can be elevated, curved around itself, and the medial (midline) margin sutured to the fascia to provide an inverted umbilicus.
Alternatively, a Z-shaped or trapezoidal flap can be used to create a deep ring through which the suprapubic tube exits.
All of these may flatten over time, and long-term studies are needed to determine which technique results in the best appearance.
14) Drainage
The suprapubic cystostomy tube and ureteral stents are secured with a nylon suture at the skin level.
Ureteral stents may exit via the neourethral lumen or the neoumbilical site if a ureteroneocystostomy was performed.
If ureteral stents are brought out the neoumbilical site, then a Silastic catheter can be used to stent the neourethra.
15) Immobilization
A spica cast or bivalved spica cast is a common technique for postoperative immobilization in order to optimize pelvic stabilization and healing.
In addition, modified Bryant’s traction can be utilized as well as external fixation.
H&A
How is the CPRE technique performed in a girl with bladder exstrophy?
1) Preparation and Assessment of the Anatomy
Total body preparation is performed similar to that for CPRE in the boy. Tegaderm is placed over the anus as described. Bilateral iliac osteotomies are completed prior to or following sterile prep depending on surgeon preference. Similar measurements are made of the bladder and urethral plate. Each ureteral orifice should be intubated with a small-caliber feeding tube and secured with absorbable suture. The bladder surface is examined for polyps, which are excised as needed. The pubic bones are identified bilaterally, and the incision lines are marked at the perimeter of the bladder, bladder neck, and urethral plate. The future neoumbilicus site is also marked in the patient’s midline at the level of the iliac crest. Similar to the operation in a male, the umbilical stump or scar is incorporated with the bladder via an inverted “V” incision that is marked at the cephalad extent of the skin incision caudal to the neoumbilicus.
2) Initial Incision and Delineation of Planes
The incision begins at the cephalad extent of the bladder and is carried along the bladder perimeter, using fine “needle point electrocautery, in similar fashi to that in the boy with BE. In the girl, the caudal extent of the dissection is delineated with the initial marking and superficial incisions along the lateral aspect of the urethral plate, just medial to the corpora cavernosa and clitoral tissue. Dissection with great care is critical at this step in order to safely maximize the urethral plate width at this level, and maintain an adequate urethral caliber, but without injuring the corpora cavernosa or clitoris. At the caudal extent of the dissection in the girl, a “Y–V” incision is made in order to advance the vaginal wall more posterior into the perineum, incorporating a thin margin of skin to provide tissue strength. Following initial dissection caudally, the dissection is continued and deepened along the perimeter of the bladder in a cephalad to caudad direction, eventually encountering the intersymphyseal bands.
3) Intersymphyseal Bands
As described in the boy, the dissection coursing caudally along the lateral aspects of the bladder wall will lead to the intersymphyseal band attachments that tether and displace the bladder trigone, bladder neck, and urethral plate anteriorly. Blunt dissection along the lateral bladder wall exploits the plane by identifying and entering the perivesical fat plane. This facilitates development of the potential space beneath the intersymphyseal band on each side of the bladder neck. Using the medial edge of the pubic bone as a reference, and a urethral sound within the vagina, the intersymphyseal bands are now carefully identified and divided. Identification and division of these bands may be the most important part of the dissection in order to allow appropriate placement of the bladder, bladder neck, and posterior urethra deep in the pelvis. A sound within the vagina helps delineate the plane between the vagina and pelvic diaphragm. The dissection is maintained along the medial aspect of the pubic bone in order to decrease the risk of injuring the clitoral tissue and connecting corporal bodies. In contrast to the boy, the urethral plate is fused to the anterior vaginal wall, and this connection is maintained intact.
4) Approximation of Tissues
“Y-V” advancement.
The vagina is advanced caudally toward the anus along the perineum as a Y–V advancement. As needed, the labia majora are advanced into the perineum alongside the vaginal orifice to provide an appropriate cosmetic appearance. The vaginal mucosa can then be approximated to the skin using interrupted absorbable sutures.
Preplacement of perineal sutures.
The urethral plate is marked along the length of the urethra to the bladder neck to ensure sufficient length and width. The urethroplasty is completed using interrupted stitches: 6-0, 5-0, and 4-0 PDS or Maxon as the sutures progress from the urethral meatus to the bladder neck. A deliberate, but gentler attempt than in boys, is made to form a bladder neck in an effort to promote continence. Interrupted sutures are used to complete the urethroplasty. A “fourcorner” suture is placed in the distal urethral tissue (but not tied) for eventual maturing of the urethral meatus (Fig. 58.13). The bladder closure is completed now in a single-layer using interrupted 4-0 PDS suture. As an option, the medial aspect of each hemiclitoris can be deepithelialized in preparation for approximation in the midline. Placement of the perineal and urethral meatus sutures prior to approximating the pubis allows optimal exposure of the tissues for accurate and precise suture placement.
Pubic bones are marked.
The perineal sutures are placed but not tied. Manually approximating the pubic bones allows for symmetry check of the perineal and genital tissue. The pubis is then approximated toward the midline by placing and tying the two sutures of 0 or #1 PDS in the same way as in the boy. The previously placed perineal sutures, which were placed under direct vision, are now tied after the pubic bones are approximated.
Abdominal wall closure, umbilicoplasty, drainage, and immobilization.
The umbilicoplasty is performed in a similar fashion as in the boy. Also, after the pubic bones are secured, the abdominal wall closure and immobilization are carried out for the girl in a similar manner as described for the boy.
H&A
What are other primary reconstructive techniques for bladder exstrophy?
Rösch and colleagues have been proponents of complete repair in early infancy including bladder closure, epispadias repair, and bilateral ureteral reimplantation without iliac osteotomy.
Baka-Jakubiak has described a one-stage approach with combined bladder neck, urethral and penile reconstruction for achieving urinary continence, and creation of a penis with good cosmesis and function in boys with EEC.
He feels that combined bladder neck, urethral, and penile reconstruction can be carried out as a one-stage procedure in selected patients who have adequate bladder capacity.
Reconstruction of the entire length of the urethra facilitates intermittent catheterization in those that require assistance with bladder emptying.
The Kelly operation is an approach consisting of a single-stage reconstruction for patients with BE or epispadias that reportedly achieves significant penile lengthening by completely detaching the insertion of the corpora cavernosa from the ischiopubic rami.
However, because of the possibility of damage to the pudendal neurovascular supply, which can lead to partial or complete penile loss, this technique is not widely used. In addition, the anatomic relationship of the pudendal NVB to the ischiopubic rami has been studied in cadavers to determine a safer approach to dissection during the Kelly procedure as the Kelly technique involves subperiosteal dissection to detach the corpora from the pubic bone.
Stein et al. have proposed urinary diversion as primary management for BE. The option of urinary diversion involves creating a functional connection between the urinary and intestinal tracts.
Although there are several variations, the basic approach is to divert urine away from the urinary bladder and into the colon for temporary storage, and then passage with the stool through the rectum.
When performed, the passage of urine is under the control of the child. The bladder and urethra are tubularized and function later in life as a conduit for semen in males.
H&E
What are the stages of MSRE repair for bladder exstrophy?
The modern staged repair of bladder exstrophy (MSRE) consists of three specific components with goals at the specific ages.
Stage I: Bladder Closure (Includes Repair of the Proximal Urethra in a Male)
Typically performed in the newborn, closure of the bladder, posterior urethra, and the abdominal wall defect results in the creation of complete epispadias (in the boy), and is performed within the first 2 months of life.
In the newborn, this closure may not be advisable if there is a small-sized and/or stiff bladder “plate,” or if the infant is premature.
In the latter setting, time allows for adequate bladder growth so that closure is feasible.
Stage II: Epispadias Repair
At approximately 6 months to 1 year of age, epispadias repair is performed. The goal is to create a straight and functional penis with a glanular meatus in the boy, and an acceptable cosmetic appearance.
Exogenous testosterone supplementation can be given prior to this surgery in the boy based on surgeon preference and penile size.
Several techniques exist for this repair in the boy. These include the Complete Penile Disassembly approach and the Modified Cantwell–Ransley technique.
A controversial component of this operation is whether to rotate the corpora inward or outward following pubic bone closure.
Stage III: Bladder Neck Reconstruction and Bilateral Ureteral Reimplantation
At approximately 4–5 years of age, BNR (and if required, bilateral ureteral reimplantation) is performed when there is documented adequate bladder capacity and motivation of the patient to participate in a postoperative voiding program.
The goal of this last stage is to provide urinary continence.
BNR approaches include the Mitchell or the Young–Dees–Leadbetter (YDL) techniques.
Stage III typically includes bilateral ureteral reimplantation as a means of creating space near the caudal extent of the bladder (bladder trigone) in preparation for the BNR procedure.
Techniques include the cross-trigonal transureteral advancement/Cohen procedure or the cephalotrigonal technique.
H&A
What are the anticipated outcomes for bladder exstrophy patients?
Outcomes after BE repair are difficult to interpret due to the wide range in treatment algorithms and the lack of a consistent system to classify voiding with continence, as compared with being dry with catheterization.
The published rates of continence vary widely from 37–90%, but there is a wide range of definitions used.
A recent review of the most commonly used definitions for urinary continence concluded that maintenance of dry periods of 3 or more hours during the day without stress incontinence is one of the most widely used.
However, other reports have used 2 or more hours.
In addition to the lack of a definition, there is often a lack of reporting of the confounding factors that are associated with the final outcome, including the age at closure, the type of closure, the additional procedures performed, and the type of emptying.
For example, case series that use the MSRE with BNR report continence rates of about 70% without bladder augmentation and CIC. Another report described a higher rate of continence of 90%, but those patients also required bladder augmentation and CIC in 70% and 67% of patients, respectively.
To date, it is not clear which surgical approach best offers the combination of preservation of normal kidney function, continence, acceptable cosmetic and functional genitalia, and overall durability with the least morbidity.
Secondary to multiple variables inherent to and potentially different for each of the two most common approaches (CPRE and MSRE), a scientifically valid comparison of the techniques is challenging and may not be feasible.
tent methods for reporting outcomes can develop concepts and practices that are universally accepted and adopted by all exstrophy centers.
A multi-institutional BE consortium (MIBEC) was recently formed to facilitate refinement of the CPRE technique, streamline follow up care and the operation, and devise and optimize outcomes in these patients.
Through the MIBEC, the volume of patients seen by each institution has increased, which has been felt to have aided in achieving proficiency in the operative technique and in tabulating outcomes.
H&A
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1) Bladder/wound dehiscence
The most devastating complication of bladder closure is dehiscence. Major contributing factors include wound infection, abdominal distension, bladder prolapse, and loss of ureteral and/or suprapubic catheters within 6 days of closure.
Urinary diversion, reclosure of the bladder as a urethral tube for later augmentation, or delayed repair of the bladder may be performed.
If not performed in the initial setting, pelvic osteotomy is frequently necessary for successful reclosure.
2) Urinary incontinence
Urinary incontinence remains a significant problem for up to 30% of bladder exstrophy patients.
In the case of bladder neck incompetence, injectable bulking agents, bladder neck sling or artificial urinary sphincter have all been applied.
Bladder neck reconstruction or formal closure of the bladder neck, with the creation of a catheterizable channel, can also be performed.
In cases where incontinence is secondary to insufficient bladder capacity, augmentation cystoplasty remains the most viable treatment option.
3) Urethrocutaneous fistula
Following epispadias repair, the most common complication is urethrocutaneous fistula, which ranges from 2% to 26% in modern series.
4) Malignancy
The incidence of adenocarcinoma of the bladder in adults with bladder exstrophy has been estimated to be 250 times that of the normal population and is likely due to chronic inflammation, infection, and metaplasia of an exposed bladder plate.
A series by Woodhouse and colleagues, however, recently documented an 800-fold risk in the incidence of bladder bladder malignancy among those with a history of bladder exstrophy by age 40.
The development of adenocarcinoma and transitional cell carcinoma of the bladder is also a potential risk in those patients who have undergone augmentation cystoplasty.
Fertility in patients with bladder exstrophy and epispadias was studied by Shapiro and colleagues, who surveyed 2500 patients. Among these, 38 men had successfully fathered children and 131 women had given birth.
Diminished fertility rates among males may be secondary to retrograde ejaculation, though libido and erectile function appear to be normal according to a report by Woodhouse and colleagues.
Female patients face a significant risk of uterine prolapse.
Coran
What is the most important factor contributing to continence after initial bladder closure?
Successful initial bladder closure is the most important factor toward achieving ultimate satisfactory urinary continence.
Some examples of outcomes include a review of 46 patients (32 males, 14 females) who underwent CPRE from 1994–2010 at a tertiary care center.
Of these, 12 patients had undergone BNR at age 5 years or older. Of the 12, six were dry day and night (dry >3 hours), and four required CIC via an appendicovesicostomy (APV), and ultimately underwent bladder augmentation.
In another series of 39 children managed with CPRE, 17 out of 23 for whom data was available achieved daytime continence of dry intervals of two hours or more. Nine of these 17 had undergone BNR with or without bladder neck injection, and three had undergone bladder neck injection.
Similarly, in this group, one child was dependent on CIC via an APV and four others used CIC via an APV to empty. One of the nine underwent augmentation cystoplasty.
In another series, 33 patients who had been referred to a tertiary care center after CPRE were reviewed. In this cohort, 19 of the 33 patients had complications of the CPRE, all of whom were closed without an osteotomy in the first week of life. Twelve males out of these 19 underwent BNR, but only 3 were able to achieve continence. All of the 14 with a successful CPRE closure underwent BNR. Eight were continent day and night, four were continent during the day, and two were wet.
H&A
What defines a good outcome after bladder neck reconstruction?
After BNR, a good outcome is defined as a dry interval >2–3 hours accompanied by spontaneous voiding without catheterization.
The classic YDL–BNR and its variants have yielded urinary continence rates of 30–80% for patients with BE.
Many factors influence these outcomes.
An initial failed bladder closure or prior failed BNR reduces the chance of attaining subsequent urinary continence.
A preoperative bladder capacity of >85 mL portends a greater continence rate after YDL–BNR.
Use of osteotomies and patient immobilization in the postoperative period increases the success of bladder closure and subsequent continence.
One long-term study found that 8 of 13 patients with an initially successful bladder closure and BNR required further reconstruction in their second decade of life because of poorly compliant, low-capacity bladders that caused urinary incontinence.
H&A
What are early complications of bladder exstrophy repair?
Complications can occur with any initial BE repair.
1) Ischemic penile injury
A devastating early complication of BE repair can be ischemic penile injury that leads to atrophy of the glans, corpora cavernosa, or urethra.
This can occur if the vascular supply to the corporal bodies is damaged during dissection or during closure of the pubic bones leading to impaired outflow and venous congestion.
There may be a higher risk in babies who are closed without osteotomy.
While the mechanism is not entirely known, it is possible that compression of the pudendal vessels may contribute to the ischemic event.
These complications are rare but can occur even in experienced hands, and it is important to be cognizant about them during the entire repair.
2) Urethrocutaneous fistula
The most commonly reported complication is an urethrocutaneous fistula (at the penopubic angle dorsally) in males.
The urethrocutaneous fistula rate varies widely from 5–40%.
In one study, complications were more common in boys who underwent epispadias repair at the same time as BE closure compared with isolated epispadias repair.
However, other studies have shown only a 9% incidence of fistulas in CPRE and 4–16% in MRSE.
Initial conservative management for a urethrocutaneous fistula is recommended, and urinary diversion via a suprapubic cystostomy tube will promote spontaneous closure in some infants.
If the fistula does not close, it should not be disturbed for 6–12 months.
Prior to the redo reconstruction, the bladder and urethra should be examined cystoscopically for the possibility of a urethral obstruction distal to the fistula and for other abnormalities.
3) Breakdown of closure
Complete breakdown of the bladder and abdominal wall closure (dehiscence) or bladder prolapse are uncommon.
Development of any of these complications may implicate a significant postoperative infection or technical error.
Formal fistula repair, or a complex reoperation including redo bladder closure and/or urethroplasty with redo osteotomies, may be required, depending on the location and size of the fistula and associated findings.
If the opening is in the urethra itself and not at the bladder neck, then formal fistula repair alone may be sufficient.
4) Bladder outlet obstruction
The other serious early complication is bladder outlet obstruction.
This is usually noted after the urethral catheter is removed when the bladder begins to cycle.
If the bladder does not empty, the urethra should be evaluated as the bladder outlet obstruction may be due to poor bladder contraction, a urethral stricture, or complete urethral obliteration in females, or a posterior urethral obstruction in males.
The suprapubic cystostomy should be left in place and changed as needed until adequate drainage is confirmed.
A rare but dangerous complication resulting from bladder outlet obstruction is bladder perforation.
This is most often in the setting of bladder augmentation, but can occur in a primarily closed bladder as well.
If a child develops chronic bladder and kidney infections following BE closure, he or she should be evaluated for possible outlet obstruction.
Early intervention with CIC for several months will often protect the patient during this time. We routinely maintain our patients on suppressive antibiotics because of the high incidence of VUR.
5) UTI
UTIs are common after BE closure. These may be lower tract infections or pyelonephritis affecting one or both kidneys.
The incidence of these UTIs increases in patients who required bladder augmentation.
Postoperative VUR is present in nearly all patients following BE repair because the ureters now pass deeply into the pelvis and enter the detrusor in a direct path with a very short tunnel.
The presence of VUR increases the risk of pyelonephritis.
Borer et al. reviewed 23 patients who underwent CPRE and found that 5 of 23 had episodes of pyelonephritis, and 5 others had cortical defects visualized on renal scan.
In a review of 57 patients who had undergone bladder neck procedures for incontinence, renal scarring was evident in 14. Also, one developed renal insufficiency in a solitary kidney, and one progressed to renal transplantation after puberty after undergoing early urinary diversion and bladder closure.
While not a true complication, a hypospadias created during the initial CPRE requires later reconstruction to relocate the meatus into an orthotopic position.
H&A
What are the salient features in a patient with cloacal exstrophy?
Although CE has been recognized for several hundred years, Rickham was the first surgeon to report successful repair and survival in 1960.
Mortality rates in CE infants remained high for years following this initial success.
Affected infants routinely died of malnutrition and sepsis.
With continuing improvement in total parenteral nutrition and neonatal management, mortality rates currently are <10%.
QOL issues are now paramount in this patient group.
The bladder plate associated with CE is divided in half by the hindgut plate, which represents the development anomaly of the colon that occurs with CE.
Ileum enters and intussuscepts into the middle of the hindgut creating appearance of the “trunk of an elephant’s face” with lateral appendiceal appendages appearing as the “tusks on the face of the elephant”.
H&A
What are the associated anomalies in cloacal exstrophy?
Renal anomalies are much more common in CE than with BE, with nearly half of the patients (48%) having one or more renal anomalies.
Anomalies include abnormal renal locations such as a pelvic kidney or crossed fused renal ectopia as well as horseshoe kidneys, renal agenesis, and ureteropelvic junction obstruction.
The most common renal anomaly is a solitary kidney, which is 30 times more likely in CE as compared with BE.
In CE, the penis is often separated into two hemiphalluses due to the wide pubic diastasis. This can make reconstructive efforts technically more challenging if the male phenotype is preserved.
Cryptorchidism is generally the rule with CE.
For girls, in addition to the genital pathology described previously with BE, uterus didelphys and other fusion anomalies of the Müllerian duct structures are seen in up to 85% of CE females.
Vaginal agenesis occurs in one-third of CE females.
In addition to the typical exstrophy of the hindgut, ileal intussusception, and the exposed appendices, other associated intestinal abnormalities include imperforate anus, foreshortening of the midgut, bowel duplication, malrotation, intestinal atresia, and Meckel diverticulum.
In addition to the features seen with BE, up to one-half of patients with CE can have other skeletal abnormalities.
These anomalies include congenital hip dislocation, talipes equinovarus, and a variety of limb deficiencies.
Given the prevalence of hip dysplasia in this population (16%), routine physical examination and plain radiographs should be performed on all CE patients.
The fascial anomalies associated with CE include those previously described for BE.
In addition, an omphalocele is often found as well.
Due to the risk of rupture, omphalocele repair in the neonatal period is recommended.
Generally, omphalocele repair occurs in conjunction with cecal separation from the hemibladder and creation of the initial hindgut colostomy, though some advocate that a single stage repair is possible in children with a small omphalocele.
A too aggressive attempt at one-stage CE repair can lead to organ ischemia from increased intra-abdominal pressure. On the other hand, rupture of an omphalocele clearly requires immediate attention and takes priority over other considerations.
Dysraphism of the lower spinal cord is reported to occur in 85–90% of patients.
Most patients have lumbar or sacral cord involvement, but thoracic level myelodysplasia has also been described.
Roughly one-third of patients will also have intracranial abnormalities associated with spinal dysraphism including Chiari malformation, hydrocephalus, and craniosynostosis.
CE management must be coordinated with closure of the neural tube defect.
H&A
What are the techniques for closure of cloacal exstrophy?
Each CE patient is unique, requiring an individualized operative plan.
In general, this plan includes:
(1) closure of the omphalocele with reapproximation of the posterior bladder halves, and tubularization of the cecum with incorporation of the hindgut into the gastrointestinal (GI) tract via an end colostomy (functionally this creates the anatomy of classic BE); and
(2) repair of the exstrophic bladder and genitalia along with approximation of the pubic diastasis.
If the baby is medically stable, the initial reconstructive procedure can be performed within the first 72 hours of life.
However, in up to 90% of these children, spina bifida is present and may need urgent closure, delaying the ventral abdominal wall closure.
Also, the omphalocele, found in almost 90% of the patients, may require immediate attention to avoid rupture.
The size of the omphalocele, the size of the cecal and bladder plates, the extent of the pubic diastasis, and the extent of comorbidities largely dictate the timing and staging of the initial closure.
If the large omphalocele cannot be closed because of increased abdominal pressure, a silo can be placed or a biosynthetic patch used to bridge the abdominal wall fascial defect.
In the past, an ileostomy was routinely performed, but the metabolic consequences can be significant.
Currently, management decisions focus around the use of the exstrophic cecal plate and the terminal blind-ending hindgut.
The cecal plate can be retained in the bladder closure as a bladder augmentation or can be separated from the bladder plates and used in the GI tract.
To improve bowel length and water resorption, most surgeons feel the cecal plate should be tubularized, making the terminal ileum, cecum, and the blind-ending hindgut all in continuity.
The hindgut segment can then be exteriorized as a colostomy.
In some cases, there are hindgut duplications. No segment of bowel should be discarded unless absolutely unusable, since it might be useful at some time for the bowel, bladder, or vaginal reconstruction.
Similarly, appendiceal segments should be preserved for possible use in reconstruction of the urinary tract.
Because of altered innervation to the pelvis, not all patients with CE are candidates for an anal pull-through procedure. The best candidates are children with an anocutaneous fistula and preserved innervation.
At the initial repair, ureteral catheters are inserted in the ureteral orifices and secured with 5-0 chromic suture.
For the omphalocele repair, the dissection begins superiorly.
Next, the umbilical vessels are ligated and the bladder plates separated from the adjacent skin as described in the CPRE and MSRE techniques.
The medial cecal hindgut plate is separated from the paired, separated bladder plates, and tubularized.
The bladder halves are then reapproximated in the midline.
This completes the first stage of a two-stage CE repair.
Inguinal hernias should be repaired if found.
A one-stage CE closure, including closure of the omphalocele, cecal plate tubularization and hindgut terminal colostomy, bladder and urethral closure, reconstruction of the external genitalia, and osteotomies, should be performed only under optimal anatomic conditions.
The decision to proceed with one-stage closure versus staged reconstruction spanning a period of months must be weighed carefully.
Following tight closure, increased abdominal pressure can cause organ ischemia, excessive tension on the midline closure, or compromised lower extremity blood flow.
In most circumstances, CE repair should be staged by converting the CE into a classic BE. A colostomy is then created.
At the time of bladder reconstruction, osteotomies should be used to assist in closure to achieve deep pelvic positioning of the urinary tract within the pelvic floor musculature.
The pubic diastasis in CE is generally more severe than in BE, and it is difficult to achieve satisfactory mobilization without osteotomies.
The Hopkins group recommends bilateral anterior innominate and vertical iliac osteotomies with gradual approximation of the bones over 1–2 weeks via external fixation and internal pins.
Other centers prefer iliac osteotomies.
Regardless of the osteotomy approach, fewer wound dehiscences and abdominal wall hernias have been reported with osteotomies.
Secondary procedures may be required on the urinary tract to achieve continence, including BNR, bladder neck closure, bladder augmentation with stomach, ileum or hindgut, and creation of a continent catheterizable stoma.
As most of these children will need CIC to achieve dryness, urinary reconstruction must be individualized to meet their needs.
H&A
What is the most severe anorectal anomaly for both sexes?
Cloacal exstrophy represents the most severe anorectal anomaly in both sexes.
The anomaly has a spectrum of presentations but always includes a mass herniated through a lower midline abdominal wall defect, combined with an imperforate anus.
The mass represents two extruded hemibladders bisected by the cecal plate.
In about one-third of cases, the distal ileum prolapses through the cecum, creating a typical “elephant trunk” appearance, which can be seen on prenatal ultrasound.
In the absence of this sign, a prenatal diagnosis is still suggested when an omphalocele is seen in the absence of a visualized bladder and the occasional presence of a distended rectum.
When spinal anomalies are diagnosed, the condition is referred to as OEIS (omphalocele, exstrophy, imperforate anus, spinal anomalies) complex. The spinal anomalies may be initially insignificant clinically (e.g., butterfly vertebra) or occur as a spinal dysraphism in the form of a myelomeningocele.
Genital anomalies are always present in the form of a bifid penis or vagina.
The pelvic bony structure is abnormal, with significant pubic diastasis resulting in an “open pelvis” configuration.
After full evaluation and stabilization of babies with cloacal exstrophy, the first surgical procedure consists of separation of the gastrointestinal and urinary tracts and closure of the omphalocele, if possible.
At the time of exploration, the small bowel should be examined, as malrotation and short intestinal length are quite common.
Running the small bowel distally will lead the surgeon to the cecal plate attached to the hemibladders.
In the past, the colon was often discarded and an end ileostomy created. This approach is now highly discouraged, as any preserved colonic segment will likely improve feeding tolerance and preserve the potential for a pull-through in some patients.
In some cases, the open cecal plate is quite wide and has to be tubularized to reestablish colonic continuity.
In more mild cases, a simple fistula exists between the cecum and the bladder.
A truncated colon is the rule in cloacal exstrophy. This ends blindly and is mobilized from the abdomen to create an end colostomy.
Bladder repair and abdominal closure can occur in one or two stages.
In premature patients with wide pubic diastasis, single stage repair is neither feasible nor safe.
Figure 40.14 depicts a baby boy with a prenatal diagnosis of OEIS made on ultrasound at 18 weeks of gestation, when an omphalocele, absent bladder, and distended rectum were seen.
The diagnosis was confirmed by MRI at 23 weeks of gestation.
The baby was born by spontaneous vaginal delivery at 35 weeks of gestation, weighing 2,400 grams.
Plain films confirmed the spinal abnormalities, consisting of a number of thoracic butterfly vertebrae, as well as absent sacral segments without dysraphism.
The findings in the baby and the initial intervention are shown in Figure 40.14.
At exploration, total small bowel length measured 56 cm.
The cecum was attached to the posterior aspect of the bladder halves by a narrow fistula.
After separation of the two structures, the two hemibladders were joined posteriorly and the blind ending colon, 10 cm distal to the cecum, was brought out as a colostomy.
Full urologic reconstruction was deferred.
The omphalocele was quite easily closed in a purse-string fashion.
Sherif
What are the principles of repair for cloacal exstrophy?
The surgical management of cloacal exstrophy is typically undertaken in the newborn period (48 to 72 hours) as a combined effort between pediatric surgery and urology.
In the setting of associated spinal dysraphism, neurosurgical consultation and closure should be undertaken as soon as the infant is medically stable.
Early operation minimizes bacterial colonization of exposed viscera and may decrease the need for pelvic osteotomy.
The traditional approach of staged repair has been thoroughly described by Gearhart and Jeffs.
Complete primary repair has also been reported by Howell and colleagues, Zderic and colleagues, Hendren, and most recently by Mitchell and Plaire.
It is generally agreed that an individualized approach toward reconstruction, whether in a single-staged or multistaged procedure, results in the best long-term outcomes.
The main goals of reconstruction include secure abdominal wall and bladder closure, preservation of renal function, prevention of short gut syndrome, creation of functionally and cosmetically acceptable genitalia, and attainment of urinary and fecal continence.
Although various operative algorithms have been published, all approaches begin with initial separation of the intervening cecal plate from the two bladder halves, closure of the omphalocele, and hindgut preservation.
In the past, the bowel was initially diverted through the creation of loop or end-ileostomies, and the hindgut segment was uniformly discarded.
This practice has since fallen out of favor in order to maximize the absorptive capabilities of the intestinal tract.
Currently, after tubularization of the exstrophied cecum, it is recommended that the hindgut segment be brought out as an end-colostomy.
In the rare instance when the hindgut remnant is not used, it may be left as a mucous fistula for use in future urologic or vaginal reconstruction.
The omphalocele is reduced to assist abdominal wall closure; however, in cases of large omphaloceles, complete initial reduction may not be possible.
In this setting, a silo device may be used or the omphalocele may be allowed to reepithelialize, converting it to a ventral hernia, which may be repaired at a later time.
The hemibladders are dissected and then reapproximated in the midline.
In infants with few other associated malformations and who are medically stable, complete closure of the abdominal wall, bladder, and phallic halves may be undertaken at this point in a single-stage procedure with or without pelvic osteotomy.
If this is not possible at the initial setting, the two bladder halves can first be joined in the midline, recapitulating the appearance of classic bladder exstrophy, which can then be repaired in a staged fashion as described in the previous section.
Genital reconstruction consists of bringing the phallic halves together to create an appearance congruent with the assigned gender.
In the male infant with cloacal exstrophy, the phallic halves are characteristically diminutive, widely separated, and asymmetric.
Historically, genetically male infants were routinely assigned to female gender at the time of initial closure, undergoing orchiectomy and feminizing genitoplasty.
Recent data regarding gender identity outcomes in gender-reassigned cloacal exstrophy patients has suggested an inherent preference toward male behaviors and sexual identities in these patients.
It remains a topic of continued study and debate.
Gender reassignment has since been largely abandoned in the current management of cloacal exstrophy, though functional and aesthetic phallic reconstruction remains challenging.
Vaginal reconstruction is necessary in females and in gender-reassigned males and is accomplished through the use of bowel or skin grafts.
Gastrointestinal reconstruction, in the form of a pullthrough procedure, may be performed in select patients, some time after initial diversion and abdominal closure. The decision is based on the potential for fecal continence and may be influenced by colonic length, ability to form solid stool, and the presence of anal stenosis versus imperforate anus.
Like those with classic bladder exstrophy, these patients will also require the creation of antireflux and urinary continence mechanisms.
The presence of myelodysplasia in these patients usually necessitates augmentation cystoplasty with a bowel segment and intermittent catheterization in order to achieve continence.
Continence procedures include creation of a neourethra, construction of a catheterizable abdominal stoma with concomitant bladder augmentation, and/or bladder neck closure, the selection of which is influenced by the presence of short gut syndrome, manual dexterity, degree of mobility, and patient motivation.
Coran
What is Hinman Syndrome?
A small number of children demonstrate persistent incontinence, repeated febrile UTI, VUR, high bladder storage pressures, and very poor emptying.
This appears to be a deeply ingrained “learned” disorder of severe voluntary detrusor sphincter dyssynergia (DSD).
In these patients, the urinary tract has the appearance of a patient with a neurogenic bladder.
There is hydronephrosis, a trabeculated bladder, reflux, and sometimes progressive loss of renal function (Fig. 56.1).
Aggressive therapy with prophylactic antibiotics, anticholinergics, alpha-blockers, UD biofeedback training, timed voiding, or clean intermittent catheterization (CIC) may be required.
Some recalcitrant cases may require bladder diversion or augmentation to avoid renal failure.
As with many “functional” disorders, the severity of Hinman syndrome tends to wane with maturation, but progressive deterioration may not permit the surgeon to wait.
H&sa
Which patients with neurogenic bladder will benefit from surgery?
Although most patients with neurogenic bladder can be managed adequately without operation, those with VUR, a poorly compliant bladder that is not responsive to medical therapy, or refractory incontinence may benefit from an operative approach.
Treatment of VUR in the neurogenic bladder is much the same as that for the normal bladder. It is imperative that the bladder is adequately treated for poor compliance and hyperreflexia (CIC and anticholinergics) before and after the operation to diminish the risk of recurrence.
In some cases, bladder augmentation may be required. Bladder augmentation is designed to create a reservoir with good compliance and adequate capacity to store urine until it can be emptied by CIC at socially appropriate intervals.
Detubularized segments of large or small bowel employed as a patch on the widely opened bladder (enterocystoplasty) are current popular techniques for augmentation (Fig. 56.4).
Another approach is gastrocystoplasty, which was used in the 1990s, but has since fallen out of favor.
Its advantages over enterocystoplasty include a decrease in mucus formation, a possible decrease in infection, and maintenance of electrolyte balance in patients with renal insufficiency. Unfortunately, the hematuria–dysuria syndrome may affect up to one-third of patients, which limits its applicability.
This problem and other complications of enterocystoplasty—metabolic derangements secondary to the absorption of urine by the gastrointestinal (GI) tract, excessive mucus production, stone formation, and a debatably increased risk of bladder cancer —have led to a search for other approaches.
Bladder autoaugmentation or detrusorectomy is an alternative augmenting technique that may prove useful in selected patients. This approach involves removal of the detrusor muscle over the superior portion of the bladder, leaving the underlying bladder mucosa intact. This creates a large compliant surface, essentially a large diverticulum, which decreases bladder pressures and increases bladder capacity at the time of filling.
The advantage of this technique is that the bladder epithelium is preserved and not replaced with GI epithelium as in bowel augmentation, thus eliminating the problems associated with the secretory and absorptive functions of bowel mucosa.
Long-term follow-up data on large numbers of children are lacking, but this technique appears to be a viable alternative for use in bladders with reasonable capacity and mainly poor compliance.
The concept has been extended to create “composite” bladders by placing demucosalized bowel or stomach patches over the urothelial bulge created in autoaugmentation.
Augmentation with ureter has also been shown to be successful, but its application is limited to patients with significant reflux to a large, dilated ureter, where the kidney or polar moiety has poor function. As the urothelial lining of the ureter is similar to that of the bladder, there are similar advantages of using ureteral augmentation (rather than bowel) as there are with autoaugmentation. In contemporary practice, however, patients with neurogenic bladders typically have close surveillance to prevent massive reflux and ureteral dilation, so this treatment modality has only limited application.
The concept of urothelial preservation during augmentation is carried forward by current innovative approaches to replace the bladder wall with biodegradable scaffolds, typically seeded with urothelial and detrusor smooth muscle cells. While the concept is promising, a recent multi-institutional phase II prospective study using autologous cell seeded scaffolds for augmentation did not show improvement in capacity or compliance, and had a high rate of adverse events.
Persistent incontinence, despite adequate treatment of the bladder to lower pressures and increase compliance, may require bladder outlet repair to increase resistance. The Young–Dees technique, which lengthens the urethra by infolding and tubularizing the trigone of the bladder, still has some advocates. Kropp’s procedure uses a tubularized anterior bladder strip reimplanted in the submucosa of the trigone to gain continence by a flap valve mechanism. Continence is commonly achieved, but catheterization is sometimes difficult. Pippi Salle’s procedure creates a similar (but easier to catheterize) flap valve by onlaying an anterior bladder wall flap onto a posterior incised strip up the middle of the trigone. Owing to the lack of a pop-off mechanism in both these procedures, if the bladder becomes overfilled, there is an increased potential for bladder rupture or for upper tract deterioration if high bladder pressure develops.
One of the more popular forms of increasing urethral resistance in a neurogenic bladder is by a bladder neck fascial sling. This procedure has many advocates and involves securing a rectus fascial strip (or other material) around the bladder neck, and suspending it from the anterior rectus fascia or pubis. This elevates and compresses the urethra to increase outlet resistance.
The artificial urinary sphincter (AUS) is a fluid-filled pressurized cuff around the urethra or bladder neck, which can be deflated by a pump-reservoir device that permits the urethra to open and the bladder to drain. The AUS can also be used in higher-pressure bladders in conjunction with bladder augmentation. The main disadvantage is that it is a mechanical device that can erode into the urethra and malfunction over time. Revision rates approach 30%, with erosion occurring in 20%. Erosion at the bladder neck is less common if there has been no prior bladder neck procedure and if the activation is delayed 6 weeks.
Children with neurogenic bladder dysfunction can continue to perform CIC with an AUS in place. In pediatric patients, however, life expectancy is ever increasing and the sphincter will eventually need revision or replacement. For this reason, we prefer to use autologous tissue techniques, when possible.
The periurethral injection of dextranomer/hyaluronic acid copolymer (Deflux), Teflon, or polydimethylsiloxane represents a simple, safe technique for enhancing urethral resistance in selected patients with poor intrinsic sphincter tone. It appears to be most applicable in patients requiring only a minimal increase in stress leak-point pressure. Longterm success is unlikely, and the usefulness of this approach in children is unclear.
With all procedures to enhance resistance at the bladder outlet, it is crucial that the storage pressures of the bladder are considered simultaneously. When the bladder outlet is tightened but the bladder is unable to store increasing volumes at low pressure, hydronephrosis or VUR results. When the surgeon is considering bladder outlet reconstruction, it may be necessary to occlude the bladder neck with a urinary catheter balloon during preoperative UD assessment to determine the bladder capacity and storage pressures to assess whether augmentation is also needed.
One beneficial adjunct in patients unable to self-catheterize their urethra (e.g., owing to spinal deformity, discomfort, or false passage) is the creation of a continent catheterizable stoma. This can be performed using the appendix or another small tubularized structure implanted into the bladder and anastomosed to the skin (Mitrofanoff principle). The implanted conduit can be hidden at the base of the umbilicus and CIC carried out using it. Alternatively, the appendix may be left in continuity with the cecum and brought to the skin as a catheterizable channel for irrigation/enemas for the neurogenic colon. In this circumstance, a small segment of ileum can be fashioned as a catheterizable Monti–Yang stoma. This concept has been a great adjunct to simplify catheterization for wheelchair-bound patients.
Cutaneous urinary diversion by ileal or colon conduit, or by cutaneous ureterostomy, is considered a last resort in these children. Long-term deterioration of the upper tracts is well documented in refluxing ileal conduits. Some protection of the upper tracts is afforded by a nonrefluxing colon conduit, but the success rate beyond two decades is uncertain. All reasonable efforts should be made to maintain ureteral drainage into the bladder.
H&A
How is urethral prolapse managed?
Urethral prolapse occurs in girls at a mean age of 5 years, with those of African descent being particularly prone to this problem.
These patients present with dysuria, blood spotting on the underwear, and a bulging concentric purplish ring of prolapsed tissue at the urethral meatus (Fig. 56.9).
Mild prolapse can be treated with an antibiotic ointment or estrogen cream applied to the area several times a day along with Sitz baths.
There are times when a catheter is needed temporarily. In persistent cases, excision of the prolapsing tissue with reanastomosis of the skin edges is curative.
Simple reduction under general anesthesia or ligation of the prolapsing urethral epithelium over a Foley catheter are other described treatment options.
H&A
How is urethral diverticulum diagnosed?
A urethral diverticulum can occur ventrally when the spongiosum is absent or is thinned.
The distal lip of the diverticulum functionally serves as an anterior urethral valve, blocking the urinary stream as it flows antegrade.
The diverticulum progressively fills during urination and further compresses the urethra. This valve effect can cause marked proximal dilation.
In some cases, there is a diverticulum with a narrow neck that does not function as a valve. Such a diverticulum can allow urinary stasis and may be a site of urethral infection.
The diagnosis is made either by urethrogram or cystoscopy.
Treatment is accomplished by endoscopic incision in the distal lip of the neck of the diverticulum or, if more pronounced, by open excision and closure of the urethral defect.
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