Inguinal, Incisional, Epigastric Hernias Flashcards
What anatomic abnormality is present in an inguinal hernia in an infant?
A. Patent processus vaginalis
B. Weakness in the inguinal floor
C. Obliteration of the inguinal floor
D. Congenital absence of both the external and internal rings
E. Direct hernia
ANSWER: A
COMMENTS: Inguinal hernias in the pediatric population occur most frequently in males (3:1), with right inguinal hernias being more common (60%).
Prematurity is strongly associated with an increased risk for having a hernia.
In contrast to hernias seen in the adult population, pediatric hernias are the result of a patent processus vaginalis, which leads to an indirect hernia.
Frequently, the diagnosis is made by identifying an inguinal bulge on examination.
Surgical correction is indicated as these hernias will not resolve with time, and there is a risk of incarceration.
Incarceration risk is highest within the first year of life.
The average rate of incarceration is between 12% and 17%, but it may be as high as 30% in 2- to 3-month-old babies.
Early repair is recommended because of the progressive rate of incarceration.
The ovary is commonly encountered when there is incarceration in females.
In young children, surgical correction consists primarily of a high ligation of the hernia sac.
The use of laparoscopy to look at the contralateral side for a synchronous patent processus and hernia is variable.
Factors associated with bilateral hernias include female gender, age less than 1 year, and the size of the index hernia. On the basis of these criteria, some surgeons recommend contralateral exploration. However, there is no consensus currently.
Which of the following is the indicated treatment for a noncommunicating hydrocele in a 2-month-old infant?
A. Observation
B. Needle aspiration
C. Hydrocelectomy through a groin incision
D. Hydrocelectomy through a scrotal incision
E. Repair of the hernia and hydrocelectomy
ANSWER: A
COMMENTS: Most noncommunicating hydroceles in young children are asymptomatic and will resolve as the fluid is absorbed.
If the hydrocele persists past 12 months of age, peritoneal communication is likely, and hydrocelectomy with ligation of the patent processus vaginalis is indicated.
In children, these operations are performed through the groin. Aspiration of the hydrocele is not recommended.
If the hydrocele is noncommunicating, it will resolve and thus make aspiration unnecessary.
If the hydrocele is communicating, the fluid will reaccumulate and an operation will be required.
What are the anatomical landmarks of the inguinal canal?
The inguinal region is between the anterior superior iliac spine and the pubic symphysis.
The inguinal canal anatomical landmarks are: the inguinal ligament, the internal and external inguinal rings, the spermatic cord in males and the round ligament in females (Fig. 17.1) [1].
Hesslebach’s triangle is defined inferiorly by the inguinal ligament, laterally by the inferior epigastric artery, and medially by the lateral border of the rectus muscle.
Hesselbach’s triangle helps differentiate indirect from direct hernias. Direct hernia’s protrude into this space, while indirect hernias pass outside the triangle through the inguinal canal.
Indirect hernias result from: weakening of the fascia of the transversalis muscle fibers at the internal inguinal ring and the potential space from a persistent processus vaginalis.
What is the processus vaginalis?
The processus vaginalis is a peritoneal diverticulum.
It extends through the internal ring at 3 months gestation.
What is the physiology of testicular descent and the pathophysiology of the development of inguinal hernias and hydroceles in infants and children?
The testis descends through the processus vaginalis between the seventh and ninth months of gestation.
A portion of the processus vaginalis attaches to the testes and is pulled with the descent of the testes into the scrotum.
The portion of the processus vaginalis surrounding the testis becomes the tunica vaginalis.
The remainder of the processus vaginalis obliterates, eliminating the communication between the peritoneal cavity and scrotum.
In males, the processus vaginalis obliterates during the first two years of life.
However, up to 40% remain patent, of which 20% will later develop into inguinal hernias or hydroceles.
The female counterpart of the processus vaginalis oblite- rates by eight months of gestation, although occasionally this will persist into childhood, which is then termed the canal of Nuck.
Indirect inguinal hernias occur more frequently on the right, as this is the side where the migration of the testicle or round ligament occurs last.
What is a hydrocele vs a hernia?
Both hydroceles and hernias result due to incomplete obliteration of the proces- sus vaginalis.
In a hydrocele, the processus vaginalis obliterates such that there is proximal and distal obliteration, but patency of the midportion.
This results in a small peritoneal opening allowing fluid accumulation around the testicle or the cord structures. This fluid may or may not communicate with the peritoneal cavity.
A hernia in comparison, is a larger peritoneal opening resulting from distal obliteration of the processus vaginalis yet the proximal aspect remains patent or there is a complete failure of obliteration allowing fluid, bowel and rarely ovaries to be present within the sac.
What type of inguinal hernia do infants and children get vs adults?
Almost all inguinal hernias in infants and children are indirect hernias. However, with rising incidence of obesity in childhood, it is possible we will see a resulting rise in incidences of direct inguinal hernias.
What is the incidence of inguinal hernias in infants and children?
The incidence of inguinal hernias is approximately 1–5% in term infants and 9–11% in infants born less than 33 weeks of gestational age [2]. The incidence in boys is 3–4 times higher than in girls, with the right side being more commonly affected.
What patient populations are at higher risk of inguinal hernias?
Preterm infants and low-birth-weight infants are at a higher risk of inguinal hernias.
Inguinal hernias are more common in children with abdominal wall defects, conditions resulting in an increased intraabdominal pressure such as VP shunts or peritoneal dialysis, connective tissue disease, genitourinary abnormalities, or family history of inguinal hernia.
What is the risk of incarceration of groin hernias in premature infants?
The reported incidence of incarcerated inguinal hernias is between 14–31% [2], usually in infants younger than 12 months.
Incarceration is the presenting sign in as many as 65% of inguinal hernias.
Due to the high incidence of incarceration, efforts are made to repair inguinal hernias shortly after diagnosis, and whenever possible prior to discharge for infants diagnosed during a NICU admission.
What is the anatomic distribution of inguinal hernias?
The right side is more commonly affected in both sexes.
This is related to the later descent of the right testicle and obliteration of the processus vaginalis.
Bilateral inguinal hernias are relatively common, with reported incidence of ~10% in full term infants, and 50% in premature and low-birth-weight infants [2].
How do non-incarcerated inguinal hernias present?
Most inguinal hernias present with an intermittent bulge in the groin.
Often this is noticed by parents at times of increased intraabdominal pressure—straining, coughing, or crying; or commonly during bath time at the days end.
Often the trigger to seek medical care is when the inguinal mass is not spontaneously reducing or the inguinal mass is significantly large.
How do you differentiate an inguinal hernia vs a hydrocele?
Communicating hydroceles are essentially hernias containing peritoneal fluid; they are differentiated through transillumination, irreducibility, nontender nature on examination and cystic in nature.
A noncommunicating hydrocele will be non- reducible and unchanging with increased intraabdominal pressure.
However, there should be normal spermatic cord felts superior to the hydrocele, often described as being able to “get above” the hydrocele.
While a hernia should be reducible as long as it is not incarcerated. An acute hydrocele of the spermatic cord can be difficult to differentiate from an incarcerated inguinal hernia.
What is the differential diagnosis of inguinal swelling in children?
Males/Females: Inguinal hernia Inguinal lymphadenopathy Granuloma inguinale Femoral hernia Amyand hernia Benign/malignant tumor: lipoma, hematomas, mesothelioma, dermoid cyst, sarcoma
Males: Hydrocoele Retractile testis Ectopic or undescended testis Traumatically dislocated testis Testicular tumor
Females:
Herniation of the ovary or fallopian tube
What are the symptoms and signs of an incarcerated inguinal hernia?
Infants or children with incarcerated inguinal hernias are often irritable and cry- ing. They may develop nausea, vomiting, abdominal distention and obstipation depending on presence of prolonged incarceration or obstructed bowel. A firm, discrete inguinal mass can be palpated which may extend into the scrotum or labia majora. This is often tender, edematous, with possible erythema of the overlying skin. In males, venous congestion can cause the testicle to appear dark blue.
What structures can become incarcerated within an inguinal hernia?
Small or large bowel, omentum, appendix, ovary or fallopian tube, and extremely
rarely a benign or malignant tumour.
What is the silk glove sign?
A palpable smooth bandlike thickening of the cord that may sometimes be appreciated by placing a single finger parallel to the inguinal canal at the level of the pubic tubercle and rubbing it from side to side. The tissues are felt to be sliding, as if sliding a silk scarf over itself. This is thought to represent the sac sliding over the cord structures. This is can be a very reliable sign in experienced hands, but requires experience to appreciate confidently.
Should you reduce an inguinal hernia, what are some of the considerations prior to attempting reduction?
Manual reduction is successful in 95–100% of pediatric patients [3].
The duration of incarceration and the age of the child influence the success rates for manual reduction, with younger patients and longer durations of symptoms reducing the overall success rates of reduction.
Elective repair after successful manual reduction has a lower complication rate than emergent operative reduction [3].
If a patient presents extremely ill with evidence of peritonitits, prolonged intes- tinal obstruction or toxicity from gangrenous bowel, manual reduction is generally contraindicated.
Often these hernias are non-reducible in nature.
The risk is that you will reduce bowel that has or is at risk of perforation, which can then result in delayed recognition and patient deterioration.
However, often in this setting, the hernia is non-reducible.
How do you reduce an inguinal hernia?
Place the patient in Trendelenburg position if possible. Align the sac using gentle traction on the scrotum to help align the hernia sac with the external ring. With gen- tle traction, you can then attempt to decompress the contents with gentle pressure on either side of the hernia neck from distal to proximal. Moving your distal hand to the apex of the mass, apply constant pressure on the inguinal canal with your other hand, pressure is applied to continue to reduce the contents, slowly walking up the groin towards the internal ring until the contents are fully reduced (Fig. 17.2) [2].
How do you manage an inguinal hernia that is not palpable on physical examination?
Observe the patient with frequent examinations, consider surgical exploration based on strong history and reliable guardians. Often, guardians will have pho- tographs, which can be a good reference. Indications for imaging with US, CT or MRI are in the setting of chronic groin or pelvic pain with unclear cause for con- cern of an occult inguinal hernia.
How do you repair an indirect inguinal hernia?
High ligation and excision of the hernia sac using either a laparoscopic or open approach.
Plication of the floor of the inguinal canal may be necessary when the inguinal ring has been enlarged with repetitive herniation. In the setting of complete break down of the transversalis fascia, a complete reconstruction of the floor of the inguinal canal using the conjoint tendon may be required.
Males who have an associated undescended testis should have an orchidopexy at the time of the inguinal hernia repair.
In females, often they will have closure of the external ring in addition to the high ligation of the hernia sac.
Where is the hernia sac located within the hernia?
The hernia sac should be located anterior and medial to the spermatic cord structures/round ligament.
When is it appropriate to repair an inguinal hernia?
With presenting incarcerated inguinal hernias, immediate surgical repair following inguinal hernia reduction eliminates the risk of recurrence.
Risk of recurrent incarceration is 16–35%, with the recurrence occurring between 0.5–120 days follow- ing the initial incarceration [3].
However, this can be a technically difficult time to perform a repair.
Tissue edema secondary to incarceration can cause distortion of the anatomical landmarks, placing cord structures at a higher risk of injury, and poor healing of the primary repair, increasing the risk of recurrence or developing a subsequent direct hernia.
A short delay in definitive operative management can allow the tissues to heal.
A general recommendation is to perform a definitive hernia repair within five days (two days for premature infants) of manual reduction of incarcerated inguinal hernias to minimize the risk of recurrence, while allowing for some recovery from the initial incarceration [3].
For children with asymptomatic inguinal hernias, a longer wait time for elec- tive surgery is associated with an increased risk of incarceration, particularly in children under one year of age [3].
Therefore, the recommendation is to perform definitive repair within 14 days of presentation.
Of course included in the decision regarding timing of the repair is the balance of risk of incarceration versus the risks associated with required anesthetic.
What are the complications associated with inguinal hernia repair?
Complications of both open and laparoscopic inguinal hernia repair:
– Vascular injury
– Post-operative seroma/hematoma (5–25%)
– Wound infection (1–2%)
– Neuralgias (0.5–4.6%)—more commonly associated with a mesh repair, which is not
commonly used in pediatric patients.
Nerves at risk are: lateral cutaneous nerve of the thigh, gentiofermoral nerve, intermediate cutaneous nerve of the thigh. Usually involved by mesh-induced fibrosis or entrapment by a tack
– Recurrence (1%)
– Vas Deferens injury (<1%)
– Testicular atrophy
Complications of open inguinal hernia repair:
– Wound infection rate is higher
Complications of laparoscopic inguinal hernia repair:
– Bladder or bowel injury with trocar placement – Identification of anatomical landmarks
– Pneumoperitoneum complications
What are the relative indications for exploration of the contralateral side?
Contralateral exploration was previously common practice, however this has declined in recent years based on large prospective studies that demonstrated children with unilateral inguinal hernias had an overall risk of metachronous hernia of 5–12% [4].
It was therefore concluded that the low incidence of contralateral hernia did not justify the routine exploration.
Contralateral exploration therefore is only warranted for children at particular risk for metachronous inguinal hernias including those with increased intraabdominal pressure, connective tissue disease, ventriculoperitoneal shunts, or chronic pulmonary disease, or in patients with an underlying medical condition, which increases their risk of anesthetic complications.
In the setting of a laparoscopic repair, the contralateral side is always inspected for possible contralateral hernia.
This is a highly sensitive and specific means of exploring the contralateral inguinal region.
What is the pathogenesis of an epigastric hernia?
Epigastric hernias can be congenital or acquired defects in the anterior abdominal wall.
Congenital epigastric hernias arise from defects in the linea alba or in an abnormally wide orifice for a blood vessel.
Other studies have suggested epigastric hernias are acquired defects from a unique pattern of aponeurotic decussation in the upper abdominal wall.
Which may be related to traction from fibers originating from the diaphragm that insert on the linea alba between the umbilicus and xiphoid.
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Epigastric hernias are also reasonably common in children, although their exact incidence is not known.
These hernias present as small midline or just off midline masses anywhere between the xiphoid and the umbilicus.
The mass is not reducible because it represents chronically incarcerated preperitoneal fat through a defect in the linea alba.
Epigastric hernias do not contain a peritoneal sac.
Therefore, there is virtually no risk of omental or intestinal incarceration.
Many are needlessly imaged by referring physicians because of the impression that they represent a soft tissue mass.
These hernias are typically asymptomatic when seen in young children.
They are repaired because they do not resolve spontaneously and can increase in size as the child gains adipose tissue with increased herniation. They can eventually produce abdominal wall pain.
The surgeon must remember that the hernia defect is usually very small and can be easily missed during the operation.
A number of pearls can assure a successful operation. Very small hernias that are difficult to palpate with the child relaxed can be observed.
Repair actually becomes easier as the hernia size increases to a small palpable mass at rest.
The hernia site should be marked with the child standing and straining prior to induction of general anesthesia, as it may be very hard to find with the child relaxed.
A 1-cm horizontal or vertical incision is made over the hernia. The herniated preperitoneal fat, which is smooth and lipoma-like, is located and dissected from the more granular subcutaneous fat. This fat nodule or mass leads to the hernia defect.
Excision of the herniated fat at the level of the defect allows its closure with a single or figure-of-eight suture in most cases.
Although the incision is usually short, it is in a very visible part of the abdominal wall. This has led some to use laparoscopic-assisted percutaneous suturing techniques.
The parents should be warned that a hard lump will be palpable in the surgical area for a few months. This represents the healing fascial closure, not a recurrence.
Sherif
How do epigastric hernias present?
Epigastric hernias typically present with a circumscribed midline epigastric
abdominal mass that may be painful or tender.
What is the incidence of epigastric hernias in the pediatric population?
Epigastric hernias represent about 4% of all abdominal hernias operated on in children.
What are the indications for surgical intervention?
All symptomatic or enlarging epigastric hernias should be surgically corrected.
Smaller or asymptomatic epigastric hernias can be observed until they either present with complications secondary to their hernia, or for cosmetic reasons, the patient would like surgical correction.
The timing of the non-symptomatic repairs is a decision made in balancing the risks associated with anesthesia if general anesthesia is required.
What is the surgical approach to repair?
Epigastric hernias have been traditionally repaired with an open surgical approach with incision over the fascial defect and primary closure. However, more recently, some are employing a laparoscopic technique.
What are the risk factors for development of an incisional hernia in the pediatric population?
The risk factors for an incisional hernia in the pediatric population overlap some- what with the adult population, but there are also specific pediatric incisional hernia risk factors.
Risk factors for pediatric patients of developing an incisional hernia include: malnutrition, immunosuppression (due to medical conditions or immunosuppressive therapy), connective tissue disorders, obesity and operation in the neonatal period.
Procedures that carry a higher risk of incisional hernia post operatively in pediatric patients include: laparotomy for necrotizing enterocolitis, stoma closure, and pyloromyotomy.
What is the incidence of incisional hernias in pediatric patients?
The incidence of incisional hernia in adults has been reported as 10–50% following any type of abdominal wall incision, with the highest being following midline incisions.
There is a paucity of data relating to the pediatric population, however recent single institution based studies have reported incidence as low as 1–3% [6].
This is likely secondary to pediatric patients having fewer patient risk factors including smoking and higher incidences of obesity.
How do incisional hernias present?
An incisional hernia should be suspected in a patient with a prior abdominal surgery who presents with abdominal pain or discomfort, skin changes overlying a prior incision, or symptoms of bowel obstruction or strangulation.
This will often be associated with a palpable abdominal mass in the location of their prior incision sites.
How are incisional hernias diagnosed?
Generally a physical examination is all that is required to diagnose an incisional hernia.
However, if there is no palpable mass appreciated, symptoms not entirely in keeping with an incisional hernia, or a complex surgical history and complex possible incisional hernia based on history or examination, an ultrasound or CT scan may be indicated to confirm diagnosis and delineate the abdominal anatomy.
When should inguinal hernias be repaired?
The presence of an inguinal hernia is an indication for elective repair.
It is not necessary to restrict an asymptomatic child’s activities preoperatively.
Prompt repair may decrease incarceration, particularly in the very young.
Inguinal hernias are common in the neonatal intensive care unit (NICU), but the timing of repair is widely variable among surgeons and between institutions and is controversial in premature infants.
Repair of an inguinal hernia shortly prior to neonatal discharge (“early”) can be more technically demanding, has higher recurrence and complication rates, may prolong mechanical ventilation and length of stay in the NICU, and is associated with an increased risk of apnea and bradycardia.
In contrast, “late” repair (after 55 weeks postconceptual age) carries an increased risk of incarceration (10–30%), more frequent emergency department and clinic visits and readmissions, and potential failure of the family to follow-up.
Concerns about the long-term neurodevelopmental risks of anesthesia in premature infants, if substantiated, would favor the late approach.
H&A
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There has been significant controversy regarding the timing of repair of inguinal hernias diagnosed in the neonatal intensive care unit (NICU).
These patients are under constant observation in the NICU, and therefore the risk of incarceration during the hospital stay is low.
Many also have chronic lung disease, representing a significant comorbidity that may be exacerbated by re-intubation and general anesthesia.
Finally, there have been concerns about possible neurodevelopmental effects of general anesthesia in neonates.
The advantages of repair prior to discharge are avoidance of incarceration after discharge and avoidance of a second hospital admission.
The disadvantages are potential increases in respiratory morbidity, difficulty of repair, risk of recurrence, and adverse neurodevelopmental effects.
There have been a number of retrospective series that have looked at this question with divergent results. A randomized controlled trial, funded by the US National Institutes of Health, is currently underway to address this question and attempt to generate high-grade evidence.
In the meantime, the surgeon should use the best judgment and make decisions regarding timing of repair in conjunction with the neonatologist and family.
For example, a baby with minimal or no lung disease, who has an intermittent hernia requiring multiple reductions in the NICU, is best repaired before discharge, whereas an oxygen-dependent baby with significant chronic lung disease and a large inguinoscrotal hernia with the bowel always residing in the scrotum may be best repaired in a delayed manner.
Sherif
How is subcutaneous endoscopic assisted ligation (SEAL) repair performed for inguinal hernias?
Laparoscopic repair of pediatric inguinal hernias is not new, being first reported in 1993. However, the procedure gained wider acceptance after laparoscopic-assisted transcutaneous techniques were introduced, decreasing the need for multiple trocar sites and intracorporeal suturing.
A number of such transcutaneous techniques using different instruments and different suture materials have been described, with the common denominator being ligation of the peritoneum at the deep ring, taking care to avoid the inclusion of the vas and testicular vessels in the ligature.
One of the more commonly employed transcutaneous techniques, SEAL, used in the index case, involves introducing a permanent braided suture on a curved needle through the abdominal wall, bisecting the ring with the suture, exiting at the opposite margin of the deep ring, reversing the swage of the needle back through the entry incision, repeating the cycle by passing the needle around the full circumference of the defect while avoiding the vas and vessels, and tying the knot in the subcutaneous tissue.
These steps are shown in Figure 18.4, in a 3-kg ex-premature baby boy.
Insufflation immediately demonstrates the bilateral hernia by resulting in scrotal distention with air.
In girls, an alternative technique is to introduce a grasper into the sac, grab its apex, invert the sac into the abdomen, ligate it using a pre-tied knot, and excise the excess.
Sherif
What is a supraumbilical hernia?
A hernia that is rarely mentioned in the literature or in surgical textbooks is the supra-umbilical hernia.
In this condition, the umbilical ring is closed and the umbilicus is normally attached to the underlying fascia.
A separate full-thickness defect, usually measuring 1–2 cm in diameter, is seen 1–2 cm above the umbilical ring.
It can be approached through a supra-umbilical incision and raising a skin and subcutaneous tissue flap superiorly.
Sherif
Which of the following is true regarding femoral hernia?
A It usually lies below and medial to the pubic tubercle.
B It usually lies inferior and posterior to the inguinal ligament.
C The lateral boundary of the femoral canal is the femoral artery.
D The lacunar ligament forms the posterior boundary of the femoral ring.
E Management is best performed using Bassini’s repair.
B
A femoral hernia occurs through the femoral canal, which is the medial compartment of the femoral sheath, and is entered via the femoral ring.
It contains fat and lymph nodes (Cloquet’s node).
The relations of the femoral ring are: inguinal ligament (anteriorly),
lacunar ligament (medially),
pectineal ligament (posteriorly) and
femoral vein (laterally).
Femoral hernias lie below and lateral to the pubic tubercle (unlike inguinal hernias, which lie above and medial), and are inferior and posterior to the inguinal ligament.
Because the femoral ring is narrow and the lacunar ligament forms a sharp medial border, irreducibility and strangulation are more common in a femoral hernia.
Femoral hernias can be repaired via either the open or the minimally invasive route.
Three approaches have been described for open surgery.
● lockwood’s infrainguinal approach
● lotheissen’s transinguinal approach
● mcEvedy’s high approach.
The infrainguinal approach is the preferred method for elective repair.
The transinguinal approach involves dissecting through the inguinal canal and carries the risk of weakening the inguinal canal.
mcEvedy’s approach is preferred in the emergency setting when strangulation is suspected. This allows better access to, and visualisation of, bowel for possible resection.
Repair is either performed by suturing the inguinal ligament to the pectineal ligament (Cooper’s ligament repair) using strong non-absorbable sutures or by placing a mesh plug in the femoral ring.
With either technique care should be taken to avoid any pressure on the femoral vein.
Bassini’s repair (conjoint tendon is approximated to the inguinal ligament) is a type of tension herniorrhaphy for the management of direct inguinal hernia.
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