Hypospadias Flashcards
Regarding repair of hypospadias, all are false, except:
A. Meatal advancement and glanuloplasty (MAGPI) is a procedure for midpenile hypospadias.
B. In Mathieu repair, flap of tissue is raised from distal to meatus.
C. In onlay island flap urethroplasty, urethral plate is removed.
D. In Mustarde procedure, tunnel is made under the urethral plate.
E. Intraoperative, to check whether penis is straight or not, penis is stretched repeatedly.
D
MAGPI is used for glanular hypospadias and sometimes in subcoronal hypospadias.
In Mathieu repair flap tissue are raised from proximal to meatus.
In Onlay Island flap, urethral plate is intact.
In Mustarde procedure, tunnel is made under the urethral plate.
Straightening of penis is confirmed by repeated intraoperative erection.
Syed/MCQ
What is the second most common congenital abnormality in the genitourinary tract of males?
Hypospadias is the second most common congenital abnormality of the genitourinary tract in males after cryptorchidism.
It is characterized by a urethral meatus that opens on the ventral surface of the penis proximal to the end of the glans. The meatus may be located anywhere along the length of the penis from the glans to a proximal location as low as the perineum.
Ventral curvature of the penis, chordee, has an inconsistent association with hypospadias.
The degree of chordee is often associated with the severity of hypospadias, with a proximal hypospadias having a more pronounced chordee.
The degree of chordee can have a significant impact on the operative technique and outcomes. For example, a subcoronal hypospadias with little or no chordee is much less complicated than is one with significant chordee and insufficient ventral penile skin.
For this reason, when discussing the degrees of hypospadias, it is more appropriate to use the clinically relevant and common classification system that refers to the meatal location after the chordee has been released.
H&A
What is the embryology of hypospadias?
Normal phallic development occurs between 6 and 14 weeks of gestation.
The first stage, a hormone independent process, which occurs in both males and females, begins around 6 weeks of gestation when the genital tubercle is formed anterior to the urogenital sinus.
The two genital folds form caudad to the tubercle, and a urethral plate develops between them.
Human chorionic gonadotropin (hCG) from the placenta stimulates the fetal testes to produce testosterone as early as 8 weeks of gestation.
Under the paracrine influence of testosterone, the inner genital folds fuse medially to create a tube that communicates with the urogenital sinus and runs distally to the base of the glans.
The formation of the penile urethra is generally completed by the end of the first trimester.
Classically, the glanular urethra is thought to form as an ectodermal ingrowth on the glans.
This ingrowth meets the distal urethra that has formed from the closure of the endodermal genital folds.
The capacious junction of these two structures gives rise to the fossa navicularis.
Recently, this theory has been challenged by the endodermal ingrowth theory. This theory suggests that the entire urethra forms from endoderm derived from the urogenital sinus and the distal endoderm cells differentiate into the stratified squamous epithelium typically seen in the distal urethra.
The formation of the glanular urethra is the last step in the formation of the urethra.
This accounts for the predominance of distal hypospadias (i.e., glanular, coronal, and subcoronal hypospadias).
Dorsal to the developing urethra, the paired corpora cavernosa develop from mesenchymal tissue.
Mesenchyme also gives rise to Buck’s fascia, dartos fascia, and corpus spongiosum.
The corpora cavernosa are the major erectile tissue components, and these are invested by the tunica albuginea.
Development of the corpora cavernosa proceeds at different rates along the ventral and dorsal surface causing a temporary ventral curvature during development.
The corpus spongiosum is the supportive erectile tissue that normally surrounds the urethra and communicates with the erectile tissue of the glans.
Buck’s fascia is the deep layer of fascia that surrounds the corpora cavernosa and is superficial to the tunica albuginea. The dorsal neurovascular bundles are deep to this layer.
Superficial to Buck’s facia is the dartos fascia, which is the loose subcutaneous layer that contains the superficial veins and lymphatics of the penis.
All these structures form subsequent to completion of the urethra by medial fusion of the outer genital folds from the proximal to the distal aspect of the penis.
This proximal to distal sequential development accounts for how a fully formed urethra can have a poorly formed spongiosum, a thin overlying skin layer, and ventral tethering (i.e., chordee) despite the meatus being located in an orthotopic position.
The last structure to completely form is the prepuce. This epithelial layer originates at the coronal sulcus and gradually encloses the glans circumferentially from proximal to distal, and from dorsal to ventral.
This development is the reason that a distal hypospadias often is associated with a dorsal hooded prepuce.
Arrested development of the urethra may leave the meatus located anywhere along the ventral surface of the penis.
Typically, this leads to arrest in the development of the other structures that ultimately form the penis and results in foreshortening of the ventral aspect of the penis distal to the meatus, which in turn leads to chordee and failure of the prepuce to form circumferentially.
H&A
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Formation of the external male genitalia is a complex developmental process involving genetic programming, cell differentiation, hormonal signaling, enzyme activity, and tissue remodeling.
By the end of the first month of gestation, the hindgut and future urogenital system reach the ventral surface of the embryo at the cloacal membrane.
The urorectal septum divides the cloacal membrane into a posterior, or anal, half and an anterior half, the urogenital membrane.
Three protuberances appear around the latter. The most cephalad is the genital tubercle. The other two, the genital swellings, flank the urogenital membrane on each side.
Up to this point, the male and female genitalia are essentially indistinguishable. Under the influence of testosterone and dihydrotestosterone in response to a surge of luteinizing hormone from the pituitary, masculinization of the external genitalia takes place.
One of the first signs of masculinization is an increase in the distance between the anus and the genital structures, followed by elongation of the phallus, formation of the penile urethra from the urethral groove, and development of the prepuce.
8 weeks AOG:
At 8 weeks’ gestation, the external genitalia remain in the indifferent stage.
The urethral groove on the ventral surface of the phallus lies between the paired urethral folds.
The penile urethra forms as a result of fusion of the medial edges of the endodermal urethral folds.
The ectodermal edges of the urethral groove fuse to form the median raphe.
12 weeks AOG:
By 12 weeks, the coronal sulcus separates the glans from the shaft of the penis.
The urethral folds have completely fused in the midline on the ventrum of the penile shaft.
During the 16th week of gestation, the glanular urethra appears.
Two possible explanations for formation of the glanular urethra have been proposed:
(1) endodermal cellular differentiation or
(2) primary intrusion of ectodermal tissue from the glans.
Anatomic and immunohistochemical studies advocate the theory of endodermal differentiation on the basis of evidence that the epithelium of the entire urethra is of urogenital sinus origin.
The entire male urethra including the glanular urethra is formed by dorsal growth of the urethral plate into the genital tubercle and ventral growth and fusion of the urethral folds.
Under proper mesenchymal induction, urothelium has the ability to differentiate into a stratified squamous phenotype with characteristic keratin staining, thereby explaining the cell type of the glans penis.
There is no evidence of ectodermal ingrowth, as proposed under the second theory.
The future prepuce is forming at the same time as the urethra and is dependent on normal urethral development.
At about 8 weeks’ gestation, low preputial folds appear on both sides of the penile shaft, which join dorsally to form a flat ridge at the proximal edge of the corona.
The ridge does not entirely encircle the glans because it is blocked on the ventrum by incomplete development of the glanular urethra.
Thus the preputial fold is transported distally by active growth of the mesenchyma between it and the glanular lamella.
The process continues until the preputial fold (foreskin) covers all of the glans.
The fusion is usually present at birth, but subsequent desquamation of the epithelial fusion allows the prepuce to retract.
If the genital folds fail to fuse, the preputial tissues do not form ventrally; consequently, in hypospadias, preputial tissue is absent on the ventrum and is excessive dorsally.
At the molecular level, testosterone must be converted to 5a-dihydrotestosterone (DHT) by the microsomal enzyme type 2 5a-reductase for complete differentiation of the penis with a male-type urethra and glans.
Coran
What is the history behind hypospadias?
Galen of Pergamon (AD 129–199) is credited as the first physician to use the term hypospadias to describe the urethral meatus in the ventral surface of penis.
At that time, Galen recommended refreshing the skin edges and stretching the penis to correct this condition.
However, the first description of hypospadias surgery is attributed to the Egyptian surgeons from Alexandria, Heliodorus and Antyllus, dating back to the first century.
Documentation by Oribasius, a Roman surgeon, dating back to the 1st and 2nd centuries, described the defect of hypospadias and its relation to problems with urination and ineffective coitus.
It further described a surgical treatment consisting of amputation of the glans distal to the hypospadiac meatus.
Little progress was made in the surgical treatment of hypospadias until the 19th century, when two Americans, Mettauer and Bush, described using a trocar to establish a channel from the meatus to the glans.
Dieffenbach also described a similar technique in the 1830s.
However, none of these methods were very successful.
In 1874, Theophile Anger reported the successful repair of a penoscrotal hypospadias using the technique described in 1869 by Thiersch for the repair of epispadias in which lateral skin flaps were tubularized to form the neourethra.
Anger’s report initiated the modern era of hypospadias surgery characterized by the use of local skin flaps. Soon after that, Duplay described his two-stage technique.
In the first stage, the chordee was released. In the second stage, a ventral midline strip of skin was covered by closure of the lateral penile skin flaps in the midline.
Duplay did not believe that it was necessary to form the urethral tube completely because he thought that epithelialization would occur even if an incomplete tube was buried under the lateral skin flaps.
Browne used this concept in his wellknown “buried strip” technique, which was widely used in the early 1950s.
In the late 1800s, various surgeons reported on penile, scrotal, and preputial flap techniques for multistage procedures.
Several of them used the technique of burying the penis in the scrotum to obtain skin coverage, similar to the technique described by Cecil and Culp in the late 1950s.
In 1913, Edmonds was the first to describe the transfer of preputial skin to the ventrum of the penis at the time of release of chordee.
At a second stage, the Duplay tube was created to complete the urethral closure.
Byars later popularized this two-stage technique in the early 1950s.
Smith further improved the outcomes by denuding the epithelium of one of the lateral skin flaps to give a “pants-over-vest” closure to reduce the risk of fistula formation.
Belt devised another preputial transfer, a two-stage procedure that was popularized by Fuqua in the 1960s.
Nove-Josserand, in 1897, was the first to report the use of a free, split-thickness skin graft in an attempt to repair hypospadias.
Over the next 20 years, various other tissues were used as free grafts, including saphenous vein, ureter, and appendix, with varying rates of success.
McCormack used a free full-thickness skin graft in a two-stage repair.
In 1941, Humby described a one-stage approach using the full thickness of the foreskin.
Devine and Horton later popularized this free preputial graft technique with very good results.
In 1947, Memmelaar described the use of bladder mucosa as a free graft technique in a one-stage repair.
In 1955, Marshall and Spellman used bladder mucosa in a two-stage technique.
Urologists in China also experienced good success with a primary repair using bladder mucosa.
This technique was developed independently during the period of scientific and cultural isolation in China.
Buccal mucosa from the lip was employed for urethral reconstruction in 1941 by Humby and has since gained renewed attention as a free graft technique.
Improvement in preputial and meatal-based vascularized flaps over the last 30–40 years have greatly advanced hypospadias repair.
Through contributions of surgeons such as Mathieu, Barcat, Mustardé, Broadbent, Hodgson, Horton and Devine, Standoli, and Duckett, the singlestage repair of even the most severe forms of hypospadias has become commonplace.
H&A
What is the incidence of hypospadias?
The incidence of hypospadias has been estimated between 0.8 and 8.2 per 1000 live male births.
In Europe the prevalence of hypospadias is estimated at 18.6 per 10,000 births, while in North America this is 34.2 per 10,000 births.
The lowest prevalence is in Asia at 0.7 per 10,000 births.
This wide variation probably represents geographic and racial differences, but of more significance is likely the exclusion of the more minor degrees of hypospadias in some reports.
If all degrees of hypospadias, even the most minor, are included, it is likely that the incidence is probably 1 in 125 live male births.
With the most quoted figure of 1 per 200–300 live male births, it can be assumed that more than 6000 boys are born with hypospadias each year in the United States.
H&A
What is the etiology of hypospadias?
The etiology of isolated hypospadias without associated disorders of sexual differentiation (DSD) is unclear.
Many theories have been proposed to explain the etiology of hypospadias. Genetic factors, inadequate hormonal stimulation, maternal/placental factors, and environmental factors have all been implicated.
It is likely that a combination of all these factors play a role in the development of hypospadias.
Deficient androgen production by the testes, failure of 5α-reductase enzyme to convert testosterone to dihydrotestosterone, insufficient hCG production by the placenta, or faulty androgen receptors in the genitalia can, in part, explain the development of hypospadias.
Various DSD are associated with hormone deficiencies or derangements that lead to hypospadias or hypospadias variants.
An endocrine cause has been implicated in some reports that show a diminished response to hCG in some patients with hypospadias, suggesting delayed maturation of the hypothalamic–pituitary axis and poor hormonal stimulation during the early crucial weeks of development.
Other reports have described an increased incidence of hypospadias in monozygotic twins, suggesting an insufficient amount of hCG production by the single placenta to accommodate the two male fetuses.
This has been further supported by linking maternal hypertension to an increased risk of hypospadias.
In utero exposure to certain medications (e.g., valproate, loperamide, paroxetine, and estrogenic or anti-androgenic medications) have been associated with an increased risk of hypospadias.
A weak association between hypospadias and the maternal exposure to progestin-like agents has also been reported.
However, no association has been found between hypospadias and oral contraceptive use before or during early pregnancy.
Interestingly, there appears to be a higher incidence of hypospadias with winter conceptions.
A large number of genes have been implicated in hypospadias. A genetic predisposition is highly suggested given the high incidence of this anomaly in first-degree relatives, with 7–10% of cases having an affected relative.
However, only 30% of isolated hypospadias cases have an identifiable genetic cause, and most are idiopathic.
The heritability of hypospadias can range between 55% and 75% with no difference between maternal and paternal transmission.
In one study that evaluated 307 families with hypospadias, the risk of hypospadias in a second male sibling was 12%.
If the index child and his father were affected, the risk for a second sibling increased to 26%.
If the index child and a second-degree relative (rather than the father) were affected, the risk of the sibling being affected was 19%.
This pattern suggests a multifactorial mode of inheritance and penetrance.
Hypospadias has been associated with multiple genetic disorders and syndromes, most notably WAGR syndrome (Wilms tumor, aniridia, genitourinary abnormalities, and mental retardation) and Denys–Drash syndrome (genitourinary malformations and susceptibility to Wilms tumor).
Both syndromes are associated with WT1 gene mutations.
H&A
What is the clinical significance of the anatomic defects in hypospadias?
The clinical significance of hypospadias is related to several factors.
The abnormal location of the meatus and the tendency toward meatal stenosis result in a ventrally deflected and splayed stream.
These factors make the stream difficult to control and often make it difficult for the patient to void while standing.
The ventral curvature associated with chordee can lead to painful erections, especially with severe chordee.
These can lead to impaired copulation due to the chordee and thus inadequate insemination.
In addition, the unusual cosmetic appearance associated with the hooded foreskin, flattened glans, and ventral skin deficiency frequently has an adverse effect on the psychosexual development of the adolescent with hypospadias.
These factors should be discussed and considered when determining timing and indication for surgical correction of hypospadias, regardless of the severity of the defect.
The distal form of hypospadias is the most common. Frequently, little or no associated chordee is present.
The size of the meatus and the quality of the surrounding supportive tissue as well as the configuration of the glans can be variable, and ultimately determine the appropriate operative approach for each patient.
Well-formed, mobile perimeatal skin and a deep ventral glans groove may allow development of perimeatal flaps to create the urethra.
In contrast, atrophic and immobile skin around the meatus may require tissue transfer, typically from the prepuce or other donor sites, to form a neourethra.
An unusual variant of the distal hypospadias is the large wide-mouthed meatus with a normal appearing circumferential foreskin (the megameatus intact prepuce variant).
Owing to the intact prepuce, this variant is often not identified until a circumcision is attempted or performed.
Historically, clinicians have opted not to perform a newborn circumcision if a hypospadias is discovered after a dorsal slit is created and the glans is exposed.
This thinking has recently been questioned, as most patients with complete prepuce have a very mild form of hypospadias, most of which require no intervention or can be repaired without the use of the prepuce.
At times, the distally located meatus may be associated with significant chordee, sometimes of a severe degree.
The release of the chordee can result in a much more proximal location of the meatus, requiring a more complicated repair to bridge the gap between the proximal meatus and the tip of the glans.
When the meatus is located on the penile shaft, the character of the urethral plate (midline ventral shaft skin distal to the meatus) is important in determining what type of repair is possible.
A well-developed and elastic urethral plate suggests minimal, if any, distal ventral curvature.
However, a thin atrophic urethral plate heralds a significant chordee.
The proximal supportive tissue of the urethra also is important.
If there is a lack of spongiosum proximal to the hypospadiac meatus, this portion of the native urethra is not substantial enough to be used in the repair. Therefore, the neourethra must be constructed from the point of adequate spongiosum by cutting back.
The position of the meatus at the penoscrotal, scrotal, or perineal location is usually associated with severe chordee, which requires chordee release and an extensive urethroplasty.
This type is usually more predictable in the preoperative period as to the choice of technique than are some of the more distal types previously discussed.
Other anatomic elements of the anomaly that are important include penile torsion, glans tilt, penoscrotal transposition, and chordee without hypospadias.
H&A
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Surgical repair of hypospadias requires an expert understanding of the normal anatomy of the penis, as well as an understanding of the anatomy of the hypospadiac penis.
The human penis consists of paired corpora cavernosa covered by a thick, elastic tunica albuginea, with a midline septum.
The urethral spongiosum lies in a ventral position, intimately engaged between the two corporal bodies.
The Buck fascia surrounds the corpora cavernosa and splits to contain the corpus spongiosum in a separate compartment.
The neurovascular bundle lies deep to the Buck fascia, and where the two crural bodies join to form the corporal bodies, the neurovascular bundle completely fans out around the corpora cavernosa, all the way to the junction of the corpus spongiosum.
This concept disagrees with the classic dogma that the neurovascular bundle lies in the 11 o’clock and 1 o’clock positions.
Superficial to the Buck fascia is the dartos fascia, which lies immediately beneath the skin. This fascia contains the blood supply to the prepuce.
The prepuce is supplied by two branches of the inferior external pudendal arteries, the superficial penile arteries. These arteries divide into the anterolateral and posterolateral branches.
In hypospadias surgery, the island flap is typically based on the anterolateral superficial vessels.
The onlay island flap, tubularized island flap, and deepithelialized pedicle flap are dependent on careful preservation of these blood vessels.
The outer skin survives from the intrinsic subcutaneous vessels.
Compared with the normal penis, the anatomy of the hypospadiac penis is no different in terms of neuronal innervation, corpora cavernosa and tunica albuginea architecture, and blood supply, except at the region of the abnormal urethral spongiosum and glans.
The nerves in both the normal and the hypospadiac penis start as two well-defined bundles superior and slightly lateral to the urethra.
As the two crural bodies converge into the bodies of the corpora cavernosa, the nerves diverge, spreading around the cavernosal bodies up to the junction with the urethral spongiosum, not limiting themselves to the 11 and 1 o’clock positions.
The 12 o’clock position in a hypospadiac penis is spared of neuronal structures, just as in a normal penis.
At the hilum of penis where the bodies of the corpora start to separate, the cavernous nerve sends nNOS-positive fibers to join the dorsal nerve of the penis, thereby changing the functional characteristics of the distal penile dorsal nerve.
Similarly, the nNOSnegative, ventrally located perineal nerve originating from the pudendal nerve becomes nNOS reactive at the cavernosa-spongiosum junction.
The redundant wiring in the penis may be important in the preservation of erectile function.
The most striking difference between the normal penis and the hypospadiac penis is a difference in vascularity.
The hypospadiac penis has large endotheliumlined vascular channels filled with red blood cells on the abnormal ventral shaft.
In contrast, the normal penis has well-defined, small capillaries around the urethra, fanning into the glans.
Anatomic studies of the urethral plate show no evidence of fibrosis or scarring.
The urethral plate is well vascularized, has a rich nerve supply, and has an extensive muscular and connective tissue backing.
These features may explain the success of incorporating the urethral plate or abortive spongiosum into hypospadias reconstruction.
Hypospadias repair requires attention to three major anatomic defects:
(1) abnormal urethral meatus,
(2) penile curvature, and
(3) foreskin defect and, in more severe cases, scrotal anomalies.
MEATAL ABNORMALITIES
Hypospadias is characterized primarily by location and configuration abnormalities of the urethral meatus.
The urethral meatus may be located only slightly ventrally, just below a blind dimple at the normal meatal opening on the glans, or it may be so far back in the perineum that it appears as “vaginal hypospadias.”
Most patients present with the meatus in one of the many transitional forms. The meatus is encountered in a variety of configurations in terms of form, diameter, elasticity, and rigidity.
It can be fissured in both transverse and longitudinal directions, or it can be covered with delicate skin.
In the case of the megameatus intact prepuce variant, the distal urethra is enlarged, tapering to a normal caliber in the penile shaft.
Often, there is an orifice of a periurethral duct located distal to the meatus that courses dorsal to the urethral channel for a short distance.
It has a blind ending and does not communicate in any way with the urinary stream.
The periurethral duct corresponds with the Gue´rin sinus or Morgagni lacunae.
Unless these ducts are inadvertently closed, leading to a blind-ending epithelial pouch, they are of no clinical consequence.
PENILE CURVATURE
The curvature of the penis is caused by a deficiency of the normal structures on the ventral side of the penis.
The causes of penile curvature are diverse: a skin deficiency, a dartos fascial deficiency, a true fibrous chordee with tethering of the ventral shaft, or deficiency of the corpora cavernosa on the concave (ventral) side of the penis.
Occasionally other penile anomalies, which represent variations of the embryologic defect causing hypospadias, are reported.
They can be characterized as a defect in the course of the urethra (congenital urethral fistula) and a group of defects characterized by curvature of the penis (chordee) without hypospadias.
SKIN AND SCROTAL ABNORMALITIES
The skin of the penis is radically changed as a result of the disturbance in the formation of the urethra.
Distal to the meatus, there is often a paucity of ventral skin, which may contribute to penile curvature.
The frenulum is always absent in hypospadias.
Vestiges of a frenulum are sometimes found inserting on either side of the open navicular fossa.
The skin proximal to the urethral meatus may be extremely thin, to the extent that a catheter or probe passed proximally may be readily apparent through the tissue-paper thickness of skin.
The urethral plate extending from the meatus to the glanular groove may be well developed.
Even with a meatus located quite proximal on the shaft, this normal urethral plate is elastic and typically nontethering.
Artificial erection demonstrates no ventral curvature in these situations.
A normal urethral plate may be incorporated into the surgical repair. However, if the urethral plate is underdeveloped, it will act as a tethering fibrous band that bends the penis ventrally during artificial erection.
When this fibrous tissue is divided, the penis frequently straightens.
Normally, the genital tubercle should develop in a cranial position above the two genital swellings.
The penis may be caught between the two scrotal halves and become engulfed with fusion of the penoscrotal area.
The boundary between the penis and scrotum may be formed by two oblique raphes that extend from the proximal meatus to the dorsal side of the penis.
Coran
What are the most common anomalies associated with hypospadias?
Inguinal hernia and undescended testes are the most common anomalies associated with hypospadias.
They occur in 7–13% of patients with a greater incidence when the meatus is more proximal.
An enlarged prostatic utricle also is more common in proximal hypospadias, with an incidence of about 10%.
Infection is the most common complication of a utricle, but excision is rarely necessary.
Several reports have emphasized significantly high numbers of upper urinary tract anomalies associated with hypospadias, suggesting that routine upper tract screening is necessary.
However, when the association is stratified by degree of hypospadias, it is evident that the types of hypospadias at risk for significant upper tract anomalies are the penoscrotal and perineal forms, and those associated with other syndromes or organ system abnormalities.
When one, two, or three other organ system abnormalities are associated with hypospadias, the incidence of significant upper tract anomalies is 7%, 13%, and 37%, respectively.
Associated myelomeningocele and imperforate anus carry a 33% and 46% incidence, respectively, of upper urinary tract malformations. In isolated proximal hypospadias, the incidence of associated upper tract anomalies is under 5%.
In midshaft and distal hypospadias, when not associated with other organ system anomalies, the incidence is similar to that in the general population.
Therefore, it is recommended that screening for upper urinary tract abnormalities with renal ultrasonography and/or voiding cystourethrogram (VCUG) be performed only in patients with proximal hypospadias (i.e., penoscrotal and perineal), and in those with anomalies associated with at least one additional organ system.
Screening should also be done in patients with other known indications, such as a history of urinary tract infection, upper or lower tract obstructive symptoms, hematuria, and in those boys having a strong family history of urinary tract abnormalities.
Males with DSD often have associated hypospadias, but the majority of isolated hypospadias are rarely associated with DSD.
When hypospadias is associated with undescended testes, micropenis, penoscrotal transposition, or bifid scrotum, DSD should be considered and warrants evaluation with karyotype along with evaluation by a multidisciplinary team with expertise and interest in DSD.
H&A
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Undescended testis and inguinal hernia are the most common anomalies associated with hypospadias.
In one series, 9.3% of hypospadias patients had an undescended testis; the incidence was 32% with posterior hypospadias, 6% for moderate, and 5% with distal.
The same investigators found the overall incidence of inguinal hernia to be 9%, with 17% of those cases associated with posterior hypospadias.
A utriculus masculinus (utricle) is more often found in cases of severe hypospadias.
Combining two large studies in severe hypospadias, there was an 11% incidence of a utricle. Usually, the only complications caused by the presence of a utricle are difficulty passing a catheter and rarely infection.
It is not surprising that urinary tract anomalies are infrequent because the external genitalia are formed after the supravesical portion of the urinary tract.
McArdle and Lebowitz found only 6 genitourinary anomalies among 200 patients with hypospadias (3%).
Cerasaro and colleagues 24 found that 1.7% of patients (4 of 233) had significant anomalies.
On the basis of a review of 169 patients, Shelton and Noe did not recommend routine urinary tract evaluation. Khuri and colleagues, in a review of 1076 patients, did not find any significant associated urinary tract anomalies.
They concluded that patients with hypospadias and an associated inguinal hernia or undescended testis did not require further urinary tract evaluation; however, patients with hypospadias and other organ system anomalies found on physical examination should undergo upper urinary tract screening with abdominal ultrasonography.
Coran
At what age is it best to repair hypospadias?
The technical advances over the past few decades have made it possible to repair hypospadias in the first 6–12 months of life in most patients.
Some surgeons have suggested delaying repair until after the child is 2 years of age.
However, most surgeons who deal routinely with hypospadias prefer to perform the repair when the patient is 6–12 months old.
One study compared the emotional, psychosexual, cognitive, and operative risks for hypospadias. The “optimal window” recommended for repair was age 6–15 months.
There is also evidence that healing may be better with decreased inflammatory factors and less scarring in the <6-month age group.
Unless other health or social problems require delay, we believe the ideal time to complete penile reconstruction in the child is between 6 and 8 months of age.
The anesthetic risk is low and, at this age, postoperative care is much easier for the parents than it is when the child is a toddler or toilet trained.
In postpubertal patients, the complication rates are significantly higher, which reinforces the concept of performing hypospadias repairs early in life.
H&A
What are the objectives of hypospadias repair?
The objectives of hypospadias correction are divided into the following categories:
- Complete straightening of the penis
- Locating the meatus at the tip of the glans
- Forming a symmetric, conically shaped glans
- Constructing a neourethra uniform in caliber
- Completing a satisfactory cosmetic skin coverage
If these objectives can all be attained, the ultimate goal of forming a “normal” penis for the child with hypospadias can be accomplished.
H&A
What are techniques in straightening penile curvature in hypospadias patients?
Curvature of the penis is difficult to judge, at times, in the preoperative period.
Artificial erection, by injecting physiologic saline in the corpora at the time of the operation, allows determination of the exact degree of curvature, which is typically ventrally.
This curvature may be caused by ventral skin or subcutaneous tissue tethering, which can be corrected with the release of skin and dartos tissue.
Infrequently, the curvature may be secondary to true fibrous tissue. In these cases, it is often required to divide the urethral plate and excise the fibrous tissue down to the tunica albuginea.
Occasionally, even after extensive ventral dissection of chordee tissue, a repeated artificial erection reveals persistent significant ventral curvature. This situation is typically secondary to corporal body disproportion caused by a true deficiency of ventral corporal development.
This problem can be corrected by one or a combination of several methods. By dissecting and elevating the urethral plate off the corpora cavernosa, the ventral tunica albuginea can be incised and augmented by inserting either a dermal patch, a piece of small intestinal submucosa, or a tunica vaginalis patch to expand the deficient ventral surface.
Elevation of the urethral plate with ventral grafting can result in devascularization of the urethral plate and increases the risk of urethral stricture.
This maneuver also prevents the use of grafts due to concern of poor revascularization of the graft and/or graft loss.
Alternatively, several nearly full-thickness ventral tunica albuginea incisions (“fairy cuts”) can be made to release the chordee without the need for ventral grafting of the corpora cavernosa.
An alternative technique includes excision of the tunica albuginea dorsally with transverse closure to shorten the dorsal surface and straighten the penis.
This should be done with caution, as it can lead to damage to the neurovascular bundle that courses dorsally.
Other surgeons have had success with multiple tandem dorsal plications without excision of the tunica albuginea, but this can result in significant shortening of the phallus and the straightening may not be long lasting.
Anatomic studies suggest that this plication should be done in the midline dorsally to avoid injury to the neurovascular bundle.
Still others advocate corporal rotation dorsally with or without penile disassembly to correct the severe chordee.
However, this is seldom required given the success with the less invasive techniques mentioned above.
Axial rotation of the penis, or penile torsion, is another aspect of penis straightening that must be managed. This problem can generally be corrected by releasing the dartos layer as far proximal as possible on the penile shaft.
Typically, this is done down to the penopubic and penoscrotal junction. This allows the ventral shaft to rotate back to the midline and corrects the torsion.
Chordee or torsion can also occur without hypospadias. The management of these boys encompasses the same spectrum of approaches as for those with hypospadias.
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What are techniques to locate the meatus at the tip of the glans during hypospadias repair?
Locating the meatus at the tip of the glans has not always been standard in hypospadias repair.
Historically, the risk of complications was thought to be too great to recommend procedures that would relocate the meatus beyond the subcoronal area.
Multistage repairs, popular in the 1950s and l960s, were designed to attain only a subcoronal location of the meatus.
Operative techniques have since improved sufficiently so that glans-channeling and glans-splitting maneuvers are used with minimal complications, thus making the distal tip meatus possible.
In glanular and subcoronal hypospadias, the configuration of the meatus is the factor that determines what technique is used to relocate the meatus on the glans.
Meatoplasty with or without dorsal advancement, urethral mobilization and tubularization (with or without incision of plate), or meatal-based flaps are the methods selected in most children with distal hypospadias.
In the more proximal forms, creating the neourethra with local vascularized skin flaps or free grafts allows positioning the urethra at the end of the penis.
Alternatively, glans channeling or glans splitting allows creation of the meatus at the tip of the glans.
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What are techniques to create a conical glans shape during hypospadias repair?
Creation of a symmetric, conically shaped glans is the objective of the glansplasty component of the repair.
Approximating the lateral glanular tissue in the ventral midline after a meatoplasty or meatal advancement corrects the flattened glans appearance and results in a conically shaped glans.
Similarly, approximation of well-developed glans wings to the midline over a neourethra in a split glans restores the glans to its normal conical shape.
H&A
What are techniques to creating a neourethra uniform in caliber, during hypospadias repair?
Formation of the neourethra can be accomplished with local skin flaps, various types of free grafts, or vascularized pedicle flaps.
Local skin flaps can be formed from in situ skin or dorsal skin transferred to the ventrum typically accomplished during staged procedures.
In either case, it is important to avoid making these flaps too narrow or thin because their blood supply can be compromised leading to complications (e.g., strictures).
The hypospadiac urethral plate has been shown in histologic studies to consist of epithelium covering well-vascularized connective tissue without fibrosis. This information supports the point that urethral plate preservation is helpful for successful urethroplasty.
Free grafts depend on an adequately vascularized bed for survival. Therefore, they should not be placed in a scarred channel, over fibrotic tissue, or over other nonvascularized grafts.
Well-vascularized subcutaneous tissue is necessary to allow adequate neovascularization and survival of the graft.
Mobilized vascularized flaps of preputium have a more reliable blood supply than do free grafts. Therefore, if they are available, these flaps are generally the choice of most surgeons.
They may be used as patches onto a strip of native urethral plate to complete the urethra, or they may be tubularized and used as bridges over the gap between a proximal native urethra and the end of the glans.
A watertight closure of the well-vascularized neourethra is formed, with care being taken to make it uniform in caliber and of appropriate size for the age of the child. This closure helps avoid stricture and the formation of saccules, diverticula, and fistulas.
H&A
What are techniques to improving the cosmesis of the penile shaft during hypospadias repair?
Creating cosmetically appealing, well-vascularized skin coverage of the penile shaft after urethroplasty can sometimes be challenging.
Transfer of vascularized dorsal preputial skin to the ventrum can be accomplished in several ways.
Buttonholes of the dorsal skin allow the penis to come through this defect, draping the distal preputium over the ventral surface of the penis. This maneuver has the advantage of transferring well-vascularized skin over the repair, but it is not cosmetically appealing.
A more satisfactory method of transferring skin to the ventrum is splitting the dorsal skin in the midline longitudinally and advancing the flaps around on either side to meet in the ventral midline. This technique allows a midline ventral closure, which simulates the median raphe. Moreover, it allows a subcoronal closure to the preputial skin circumferentially, which simulates the suture lines of a standard circumcision.
Another adjunct is to advance lateral flaps of inner preputial skin from each side to the ventral midline of the penis at the time of glansplasty or closure of glans wings. Approximating these flaps in the midline gives the appearance of an intact circumferential preputial collar, further enhancing the potential for an anatomically normal skin closure.
Some patients, particularly those in European countries, prefer the appearance of an uncircumcised penis. In distal repairs, reconstruction of the prepuce for an uncircumcised appearance can be accomplished if desired.
Correction of the more significant degrees of penoscrotal transposition is often necessary to avoid a feminizing appearance in patients with proximal hypospadias.
In some cases, this step can be done at the time of the original repair.
However, when using vascularized pedicle flaps for the repair, it is usually safer to correct significant penoscrotal transposition with rotational flaps at a later time.
H&A
How do you decide on the best operative approach for hypospadias?
Due to the wide variation in the anatomic presentation of hypospadias, no single urethroplasty is applicable for every patient.
At times, a final decision regarding the degree of curvature and the ultimate location of the meatus cannot be made until the operation has started, the penis is degloved, and an artificial erection is created.
The surgeon who repairs hypospadias must be adaptable and experienced to deal with all variants of the defect.
Versatility and experience with all options of surgical treatment are the keys to successful management.
By recognizing the subtle nuances of meatal variation, glans configuration, and curvature character, the experienced surgeon can choose the optimal technique.
H&A
What surgical approaches are preferred for distal variant hypospadias?
Some glanular variants are amenable to the meatal advancement and glansplasty (MAGPI) repair.
A stenotic meatus with good mobility of the urethra and a fairly shallow ventral glanular groove are the anatomic characteristics best suited for the MAGPI.
A widemouthed meatus is not amenable to the MAGPI repair. The meatal-based flap repair may also be used effectively in this situation, assuming no chordee is present, and mobile, well-vascularized skin is present proximal to the meatus.
This repair works well when there is a moderately deep ventral groove, allowing the urethra to be placed deep in the glans and a conically shaped glans to be created after closure of the glans wings over the skin flap.
The glans approximation procedure (GAP) is useful when a wide-mouthed proximal glanular meatus is found with a very deep groove.
The pyramid procedure is well suited for the fish-mouth type of meatus seen in the megameatus intact prepuce variant.
These repairs give excellent cosmetic result when performed in appropriately selected patients.
The tubularized incised plate urethroplasty (TIP) is a modification of the Thiersch–Duplay tubularization, which involves a deep longitudinal incision of the urethral plate in the midline. This allows the lateral borders of the urethral plate to be mobilized and closed in the midline without tension.
This procedure also allows repair of the wide-mouthed meatus variant with a flat, shallow ventral groove without the need for additional flaps.
Over the last decades, the TIP urethroplasty has gained wide acceptance. Its durability and long-term success have been demonstrated even in the more proximal variants.
H&A
What surgical approaches are preferred for midshaft variant hypospadias?
The amount of ventral curvature generally dictates the type of repair in middle- and distal-shaft hypospadias.
When no significant chordee is present, the TIP repair can frequently be performed.
Another approach is the onlay island flap technique. This procedure involves mobilizing an inner preputial flap on its pedicle and rotating it ventrally to lay on the well-developed ventral urethral plate to complete the tubularization of the neourethra. This technique is applicable to many forms of midshaft/penile hypospadias.
In milder degrees of chordee, the curvature can be corrected without dividing the urethral plate by incising tethering bands lateral to the urethral plate or by dorsal plication techniques. This allows either the onlay island flap technique or TIP to be used instead of the tubularized pedicle flap or free graft, which have a higher incidence of complications.
If significant chordee is present, division of the urethral plate may be necessary. This moves the meatus to a more proximal location and may require treatment as described for proximal hypospadias.
H&A
Which surgical approaches are preferred for proximal variant hypospadias?
Many of the penoscrotal, scrotal, and perineal forms of hypospadias are associated with significant chordee, which may require division of the urethral plate and results in a gap between the proximal native urethra and the tip of the glans.
This gap can be bridged with staged procedures in which coverage of the ventral penile shaft is attained by rotation of a dorsal flap or free graft transferred to the ventrum, with tubularization to form the neourethra at a later time (i.e., staged repair).
Another method is the tubularized free graft anastomosed to the native urethra proximally and extended to the end of the glans by a tunneling or splitting technique.
The most commonly used free grafts are full-thickness skin, bladder mucosa, or buccal mucosa.
Preputial skin is much preferred to extragenital skin.
If genital skin is not available, buccal mucosa may be the next best option.
Vascularized flaps are a more physiologically sound alternative to free grafts.
The transverse inner preputial island flap that is tubularized and transposed ventrally to form the neourethra is the preferred vascularized flap.
In contrast to free grafts, it provides good preputial skin with a reliable blood supply that does not rely on neovascularization for healing of the neourethra.
Occasionally, the length of the prepuce alone may not be adequate to bridge the defect of a very proximal hypospadias. In this case, the shiny non-hair-bearing skin around the meatus can be tubularized, and the proximal urethra is mobilized to a more distal location.
The preputial vascularized tube graft can then be used to bridge the remaining distance to the end of the penis.
In the rare case in which the skin deficiency is so severe that a vascularized pedicle cannot be used or in which the chordee is so severe that a graft is required to correct the chordee, a two-stage repair may be the best option.
The authors prefer a two-stage repair using an inner prepuce graft or flap depending on the degree of chordee. If the inner prepuce is not available, too short, or poorly developed, a buccal graft is preferred as long as there is an adequate vascular base for grafting.
The transverse island flap as a one-stage procedure is an alternative for most cases of proximal hypospadias with chordee and adequate penile shaft skin for coverage.
H&A
What are the indications and steps for MAGPI repair of hypospadias?
Some glanular variants are amenable to the meatal advancement and glansplasty (MAGPI) repair.
A stenotic meatus with good mobility of the urethra and a fairly shallow ventral glanular groove are the anatomic characteristics best suited for the MAGPI.
A widemouthed meatus is not amenable to the MAGPI repair.
The meatal-based flap repair may also be used effectively in this situation, assuming no chordee is present, and mobile, well-vascularized skin is present proximal to the meatus.
This repair works well when there is a moderately deep ventral groove, allowing the urethra to be placed deep in the glans and a conically shaped glans to be created after closure of the glans wings over the skin flap.
H&A
What are the steps and indications for the GAP repair for hypospadias?
The glans approximation procedure (GAP) is useful when a wide-mouthed proximal glanular meatus is found with a very deep groove.
The pyramid procedure is well suited for the fish-mouth type of meatus seen in the megameatus intact prepuce variant.
These repairs give excellent cosmetic result when performed in appropriately selected patients.
H&A
What are the indications and steps in TIP repair of hypospadias?
The tubularized incised plate urethroplasty (TIP) is a modification of the Thiersch–Duplay tubularization, which involves a deep longitudinal incision of the urethral plate in the midline.
This allows the lateral borders of the urethral plate to be mobilized and closed in the midline without tension.
This procedure also allows repair of the wide-mouthed meatus variant with a flat, shallow ventral groove without the need for additional flaps.
Over the last decades, the TIP urethroplasty has gained wide acceptance.
Its durability and long-term success have been demonstrated even in the more proximal variants.
The amount of ventral curvature generally dictates the type of repair in middle- and distal-shaft hypospadias. When no significant chordee is present, the TIP repair can frequently be performed for these variants.
In milder degrees of chordee, the curvature can be corrected without dividing the urethral plate by incising tethering bands lateral to the urethral plate or by dorsal plication techniques.
This allows either the onlay island flap technique or TIP to be used instead of the tubularized pedicle flap or free graft, which have a higher incidence of complications.
If significant chordee is present, division of the urethral plate may be necessary. This moves the meatus to a more proximal location and may require treatment as described for proximal hypospadias.
H&A
What are the indications and steps in performing the onlay island flap repair for hypospadias?
This procedure involves mobilizing an inner preputial flap on its pedicle and rotating it ventrally to lay on the well-developed ventral urethral plate to complete the tubularization of the neourethra.
This technique is applicable to many forms of midshaft/penile hypospadias.
In milder degrees of chordee, the curvature can be corrected without dividing the urethral plate by incising tethering bands lateral to the urethral plate or by dorsal plication techniques.
This allows either the onlay island flap technique or TIP to be used instead of the tubularized pedicle flap or free graft, which have a higher incidence of complications.
If significant chordee is present, division of the urethral plate may be necessary. This moves the meatus to a more proximal location and may require treatment as described for proximal hypospadias.
H&A
What are the indications and steps in performing a mental-based flap repair for hypospadias?
For distal hypospadias, with immobile urethra and good perimeatal tissue.
If perimeatal tissue is thin, an onlay island repair is preferred.
What are the indications for staged repair in hypospadias?
Many of the penoscrotal, scrotal, and perineal forms of hypospadias are associated with significant chordee, which may require division of the urethral plate and results in a gap between the proximal native urethra and the tip of the glans.
This gap can be bridged with staged procedures in which coverage of the ventral penile shaft is attained by rotation of a dorsal flap or free graft transferred to the ventrum, with tubularization to form the neourethra at a later time (i.e., staged repair).
H&A
What are the steps and indications for transverse preputial island flap tube repair in hypospadias?
Many of the penoscrotal, scrotal, and perineal forms of hypospadias are associated with significant chordee, which may require division of the urethral plate and results in a gap between the proximal native urethra and the tip of the glans.
This gap can be bridged with staged procedures in which coverage of the ventral penile shaft is attained by rotation of a dorsal flap or free graft transferred to the ventrum, with tubularization to form the neourethra at a later time (i.e., staged repair).
Another method is the tubularized free graft anastomosed to the native urethra proximally and extended to the end of the glans by a tunneling or splitting technique.
The most commonly used free grafts are full-thickness skin, bladder mucosa, or buccal mucosa.
Preputial skin is much preferred to extragenital skin. If genital skin is not available, buccal mucosa may be the next best option.
Vascularized flaps are a more physiologically sound alternative to free grafts. The transverse inner preputial island flap that is tubularized and transposed ventrally to form the neourethra is the preferred vascularized flap.
In contrast to free grafts, it provides good preputial skin with a reliable blood supply that does not rely on neovascularization for healing of the neourethra.
Occasionally, the length of the prepuce alone may not be adequate to bridge the defect of a very proximal hypospadias.
In this case, the shiny non-hair-bearing skin around the meatus can be tubularized, and the proximal urethra is mobilized to a more distal location. The preputial vascularized tube graft can then be used to bridge the remaining distance to the end of the penis.
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