543P. Mattei (ed.), Fundamentals of Pediatric Surgery, DOI 10.1007/978-1-4419-6643-8_69, © Springer Science+Business Media, LLC 2011

Hernias are among the most common conditions encountered by pediatric surgeons. Although inguinal and umbilical her-nias are by far the most prevalent, rarer types of hernias are occasionally encountered in children. Because they are so rare, most of the information regarding the treatment of these conditions is anecdotal. A clear understanding of the anat-omy and techniques for repair of these hernias is critical for developing an appropriate management plan. An incorrect or delayed diagnosis can lead to significant complications, including bowel obstruction, ischemia, or perforation.

Unusual Inguinal Hernias

Incarcerated hernias with unusual contents and historically named after Littre, Amyand, and Richter, can occur in any abdominal wall or inguinal defect. Although rare in any age group, Littre’s hernia, in which the hernia sac contains a Meckel’s diverticulum, are extremely uncommon in the pedi-atric population. Preoperative diagnosis is nearly impossible. Radiographic evaluation (US, CT) is often unhelpful, aside from confirming the presence of a hernia. The usual evalua-tion for a suspected incarcerated hernia should be undertaken to ensure prompt reduction and to prevent ischemic conse-quences. Besides bowel ischemia, other complications include pain, bleeding, and perforation. Inflammation of the Meckel’s diverticulum can create dense adhesions to the hernia sac. The optimal treatment consists of hernia repair and resection of the diverticulum. If thorough inspection and proper resection are not possible through the inguinal incision, it might be neces-sary to make an additional incision on the abdomen. Proponents of laparoscopic hernia repair have reported cases in which the Meckel’s diverticulum was identified and reduced laparo-scopically, and then resected through an umbilical incision.

This approach might allow better visualization of the bowel than is possible through a standard inguinal incision.

Amyand’s hernia is an inguinal hernia in which the hernia sac contains a normal or acutely inflamed appendix. As with Littre’s hernias, they are nearly impossible to diagnose pre-operatively. The presentation is similar to that of any incar-cerated or strangulated inguinal hernia: tenderness, erythema, inability to reduce the hernia contents. There are several case reports in the literature of acute appendicitis occurring within a hernia sac mimicking a strangulated inguinal hernia or tes-ticular torsion. The significance of acute appendicitis within the sac is unclear. Inflammation of the appendix can be inci-dental or perhaps a consequence of incarceration.

The treatment of Amyand’s hernias consists of hernia repair and appendectomy, which can be performed using a laparo-scopic-assisted approach. Postoperative management depends on the condition of the appendix at the time of surgery. Prolonged hospitalization for long-term antibiotics is some-times necessary for perforated appendicitis and patients should be monitored for complications such as intra-abdominal abscess and sepsis.

Richter’s hernia occurs when only the antimesenteric por-tion of a segment of bowel wall protrudes through a hernia defect. Because the entire circumference of the intestine is not involved, these hernias do not present with the usual symptoms of a bowel obstruction even in the setting of incarceration. This can lead to bowel wall ischemia and perforation if unrecog-nized or if an involved ischemic segment is unknowingly reduced. Therefore, surgeons should have a high index of sus-picion for ischemia if a child has abdominal symptoms follow-ing hernia reduction or repair. The treatment is a standard hernia repair, with careful inspection of the involved intestinal segment, if necessary using an abdominal counter-incision.

Femoral Hernias

Femoral hernias account for approximately 1% of pediatric groin hernias. They are frequently misdiagnosed, as often as 75% in some series. The femoral hernia is often confused

S.J. Timmapuri (*) Department of Pediatric Surgery, Drexel University, St. Christopher’s Hospital for Children, Erie Ave at Front Street, Philadelphia, PA 19134, USA e-mail: shaheen.timmapuri@tenethealth.com

Chapter 69Uncommon Hernias

Shaheen J. Timmapuri and Rajeev Prasad

544 S.J. Timmapuri and R. Prasad

with an indirect inguinal hernia and the correct diagnosis is usually made upon inguinal exploration. It can also be mis-taken for an enlarged lymph node, lipoma, or abscess. Because these hernias are so rare in children, understanding the anatomy is critical for making a correct diagnosis and ensuring appropriate and prompt treatment.

The etiology remains unclear but an anatomic defect, such as an enlarged femoral ring, is probably the cause in most cases. Though more common in adults, acquired etiologies (increased intra-abdominal pressure, prior inguinal surgery) are in some cases thought to be contributing factors. The majority of pedi-atric patients with femoral hernias are less than 10 years of age, supporting a congenital rather than acquired etiology.

As the diagnosis is usually not considered preoperatively, many patients present with a recurrent groin bulge after an inguinal hernia repair. Femoral hernias are located lateral and inferior to the pubic tubercle and inferior to the inguinal ligament. The diagnosis can usually be made by thorough physical examination. Some patients complain of pain in the ipsilateral lower extremity, which is caused by pressure on the femoral nerve. The pain disappears with flexion of the thigh (Astley Cooper sign).

Many surgical techniques for the repair of femoral hernias have been described; but because these hernias are rarely reported in children, no large series exist to objectively com-pare them. The McVay hernia repair (approximation of Cooper’s ligament to the conjoined tendon) is probably the most widely used technique. Laparoscopy has recently been described for the diagnosis and repair of femoral hernias.

The most common error made regarding femoral hernia repairs is misdiagnosis. This results in inadequate treatment at the first operation and patients being subjected to repeated procedures for a “recurrent” hernia. In patients with negative explorations for suspected indirect inguinal hernias, the diag-nosis of a femoral hernia should be considered. The most significant operative complications are recurrence and intes-tinal compromise secondary to strangulation.

Spigelian Hernias

Fewer than fifty cases of Spigelian hernia in the pediatric age group have been reported in the literature. These hernias occur lateral to the rectus abdominus muscle along the semi-lunar line. In adults and older children, these hernias are thought to be the result of trauma, neoplasms, or prior abdominal operations. However, the occurrence of Spigelian hernias in neonates has raised the possibility of a congenital etiology. In these patients, associated findings of inguinal hernias and cryptorchid testes have been described.

The diagnosis of a Spigelian hernia can be made clinically when a bulge is present along the semilunar line. This is often a subtle finding because of the overlying intact external

oblique muscle, which prevents complete herniation of abdominal contents. If unclear clinically, US, CT or MRI sometimes aids in confirming the diagnosis. Once diagnosed, Spigelian hernias should be repaired in order to alleviate asso-ciated discomfort and prevent incarceration. Primary repair is almost always possible in children and can be accomplished through a transverse incision directly over the fascial defect. Prosthetic material is sometimes necessary for larger defects. Laparoscopy has been found to be very useful for both diag-nosis and treatment. The hernias can be repaired entirely lap-aroscopically or by using laparoscopy as an adjunct to identify the exact site of the hernia and guide incision placement.

Because of the often subtle nature of Spigelian hernias, the diagnosis is challenging. In patients without an obvious bulge on examination but with a good history, radiologic studies might be helpful. Recurrence after repair is rare, especially with small defects. Other complications relate to intestinal ischemia secondary to incarceration.

Lumbar Hernias

Although approximately 10% of all lumbar hernias are con-genital in origin, congenital lumbar hernias (CLH) account for the majority of cases in children. In older children and adults, acquired lumbar hernias result from trauma, infection or prior surgery. The most common types are Grynfelt-Lesshaft her-nias and Petit hernias. Grynfelt-Lesshaft hernias occur in the superior lumbar triangle, bordered by the inferior aspect of the 12th rib, the internal oblique muscle, and the quadratus lum-borum. Petit hernias occur in the inferior lumbar triangle, whose borders are the external oblique muscle, the latissimus dorsi muscle, and the iliac crest. Combinations of both hernia types are occasionally seen and result in a large defect.

The etiology of CLH is not completely clear. Possible fac-tors are developmental anomalies, such as aplasia of lumbar muscles, nerve entrapment, and increased pressure due to an intra-abdominal mass. Most present in the first year of life. They tend to be unilateral and have well-defined borders. The diagnosis is made on physical examination and the classifica-tion is based on the anatomic location. Associated anomalies are present in nearly two-thirds of patients with CLH. These include lumbocostovertebral syndrome, caudal regression syndrome, diaphragmatic hernia, ureteropelvic junction obstruction, cloacal exstrophy, and, rarely, lipomeningocele.

After the associated medical conditions are properly addressed, repair of CLH is recommended to prevent incar-ceration. As with other hernia types, primary repair is the pre-ferred method; however, especially with combined defects, the hernia can involve the entire lateral abdominal wall, and repair with prosthetic material is often necessary. Recurrence is rare and usually occurs in patients with other significant morbidities.

54569 Uncommon Hernias

Traumatic Abdominal Wall Hernias

Traumatic abdominal wall hernias (TAWH) are rare defects which result from high- or low-velocity blunt trauma. The actual injury is caused by an object projecting enough force to cause damage to muscle and fascial layers without penetrat-ing the skin. The elastic nature of the skin allows it to remain intact while the other abdominal wall layers are disrupted. Three types of TAWH have been described: Type I hernias are small defects caused by blunt trauma (handlebar injury), Type II result from high-velocity traumas (motor vehicle accidents, falls) and tend to be larger, and Type III, which typically result from deceleration injuries and involve herniation of intra-abdominal contents. TAWH are usually seen in the lower abdomen but can occur anywhere on the abdominal wall.

Not all TAWH are evident immediately following the traumatic event but rather can present in a delayed fashion weeks or months later. To make the diagnosis of TAWH, patients should have had clear abdominal wall trauma with-out evidence of a hernia prior to the injury. The diagnosis is usually based on history and physical examination, however swelling or hematoma in the area of injury can obscure the bulge of the hernia, in which case radiographic studies (plain

abdominal films, US, CT) can be useful for confirming the diagnosis and excluding other injuries.

Although all patients with abdominal trauma must be care-fully evaluated, children with the smaller Type I defects rarely have concurrent intra-abdominal injuries. Repair is indicated whenever the diagnosis is made. Other traumatic injuries must be appropriately addressed, sometimes necessitating laparotomy. However, in the absence of other intra-abdominal pathology, a local wound exploration with primary closure of the hernia in multiple layers should be performed. Larger defects might require the use of prosthetic material for an adequate tension-free closure. Diagnostic laparoscopy is used in some patients to evaluate abdominal injuries and obviate the need for a larger laparotomy incision. This approach allows for a thorough abdominal exploration and subsequent local hernia repair in patients with no additional injuries.

Rare hernias in the pediatric population are frequently difficult to diagnose. Physical findings are vague and radio-graphic studies are unhelpful. Misdiagnosis of these defects can have serious consequences such as bowel ischemia, obstruction, and perforation. A clear understanding of the anatomy, along with a preoperative management plan, aid in the diagnosis and treatment of these uncommon hernias.

Summary Points

Understanding the anatomy and repair techniques for various uncommon hernias is critical for appropriate diagno-•sis and management.Diagnosis of most hernias is based on history and physical examination.•Misdiagnosis leads to complications, including bowel obstruction, incarceration, and perforation.•

Editor’s Comment

One of the rarest hernias seen in children is the direct inguinal hernia. Essentially all pediatric inguinal hernias are of the indirect variety (patent processus) and therefore high ligation is all that is necessary. It is very rare to discover that the floor of the inguinal canal is deficient either before or during an inguinal hernia repair. With the possible exception of a second recurrence or a child with a known connective tissue disorder, the use of an artificial material is not recommended for inguinal hernia repair in a child because of the uncertain long-term effects and the possibility of injury to adjacent structures. Rather, a traditional technique, such as the McVay Cooper ligament repair, is favored.

Spigelian hernias are frequently considered but rarely found. Patients will sometimes provide a history that is text-book, only to have intact fascia by physical examination, imaging studies, and even local exploration. It can be very

frustrating for all involved. Although MRI and laparoscopy provide the best available techniques for confirmation of a her-nia, no study or combination of studies is especially accurate.

The eponymous inguinal hernias are mostly of historical interest as they rarely cause true clinical mayhem – when per-forming an inguinal hernia repair, the surgeon must be pre-pared to deal with any number of surprises. The one exception is the Richter’s hernia, which can be easily missed when one assumes that incarcerated hernia has been ruled out because of the absence of obstructive symptoms. The consequences of this error, bowel necrosis and perforation, can be dire. Imaging studies can also be deceiving, reinforcing the adage that, when in doubt, the patient should be explored.

Diastasis recti is not a true hernia and should never be oper-ated upon, but parents often need to be repeatedly reassured. Likewise, epigastric hernias (epiploceles) should only be repaired if they become large or symptomatic. Despite being true hernias, they are almost always tiny, allowing only a small amount of properitoneal fat to herniated, and are thus generally

546 S.J. Timmapuri and R. Prasad

harmless. Finally, incisional hernias can occur whenever a surgical procedure has been performed and are usually easily confirmed on physical examination. The exception is the rare trocar site hernia, which can be difficult to diagnose. The combination of pain and a lump at a trocar site should usually prompt surgical exploration to rule out a hernia.

Differential Diagnosis

Littre’s hernia (contains Meckel’s diverticulum)•Amyand’s hernia (contains appendix)•Richter’s hernia (incarcerated antimesenteric por-•tion of bowel)Femoral hernia•Lymphadenopathy•Abscess•Spigelian hernia•Traumatic abdominal wall hernia•Lumbar hernia•Traumatic abdominal wall hernia•

Diagnostic Studies

Plain radiographs −Ultrasound −CT −MRI −

Preoperative Preparation

Informed consent□□Careful evaluation of preoperative studies□□

Parental Preparation

Risk of infection, bleeding (hematoma), error in diag- −nosis, and recurrence.Some abdominal wall hernias are rare and difficult to −confirm or exclude even with sophisticated imaging modalities.

Technical Points

Although not always possible, accurate preoperative •diagnosis allows appropriate operative planning.Careful evaluation of involved bowel is critical to •identify an ischemic or perforated segment.Laparoscopy is a useful adjunct in the diagnosis and •management of unusual hernias.

Suggested Reading

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DeCaluwe D, Chertin B, Puri P. Childhood femoral hernia: a commonly misdiagnosed condition. Pediatr Surg Int. 2003;19:608–9.

Fakhry SM, Azizkhan RG. Observations and current operative manage-ment of congenital lumbar hernias during infancy. Surg Gynecol Obstet. 1991;172:475–9.

Goliath J, Mittal V, McDonough J. Traumatic handlebar hernia: a rare abdominal wall hernia. J Pediatr Surg. 2004;39:e20–2.

Livaditi E, Mavridis G, Christopoulos G. Amyand’s hernia in prema-ture neonates: report of two cases. Hernia. 2007;11:547–9.

Losanoff JE, Richman BW, Jones JW. Spigelian hernia in a child: case report and review of the literature. Hernia. 2002;6:191–3.

Messina M, Ferrucci E, Meucci D, et al. Littre’s hernia in newborn infants: report of two cases. Pediatr Surg Int. 2005;21:485–7.

Temiz A, Akcora B, Temiz M, et al. A rare and frequently unrecognized pathology in children: femoral hernia. Hernia. 2008;12:553–6.

Tycast JF, Kumpf AL, Schwartz TL, et al. Amyand’s hernia: a case report describing laparoscopic repair in a pediatric patient. J Pediatr Surg. 2008;43:2112–4.

Wakhlu A, Wakhlu AK. Congenital lumbar hernia. Pediatr Surg Int. 2000;16:146–8.

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