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Pediatric Hernia Repair
Inguinal, Femoral and Umbilical

Inguinal hernia is the most frequent condition requiring surgery in the pediatric age group. It is more common in premature, preterm, and underweight babies. Inguinal hernias invariably present as a changing mass in the groin. Femoral hernia presents as a mass below the inguinal ligament. Umbilical hernia is fairly common and presents with an enlarged defect of the umbilical ring. A defect of varying size is normally present at birth. Inguinal and femoral herniorraphy (repair of the hernia) is usually undertaken as soon as the baby will tolerate the procedure because of concern of strangulation of hernia contents (usually bowel). Improvements in pediatric anesthesia and neonatal/pediatric intensive care units have made herniorrhaphy a low risk operation even in sick children.

Inguinal Hernia

  • The abdominal wall in the groin area is made up of different structures going from deep to superficial layers (Figures 1 and 2):
    1. Peritoneum - the lining of the abdominal cavity (becomes the hernia sac)
    2. Subperitoneal fat - fat beneath the peritoneum
    3. Transversalis fascia - sheet of fibrous tissue that envelops the peritoneum
    4. Transversus abdominis muscle
    5. Internal oblique muscle
    6. External oblique muscle
    7. Subcutaneous fat
    8. Skin
Figure 1 - Layers of the abdominal wall, inguinal canal and their relations to the spermatic cord and testies. © C. SaliciFigure 2 - Anatomy of the inguinal canal and relationship to the pelvic bone. © C. Salici
  • During development the testis (testicle) normally descends from a higher location (near the lower pole of the kidney) pulling a covering of peritoneum (the processus vaginalis) with it to become fixed in the scrotum
  • The testicle and spermatic cord penetrate the abdominal wall through an opening called the internal inguinal ring. The cord then runs obliquely through the inguinal canal to exit the abdominal wall through the external inguinal ring near the scrotal sac. A similarly placed cord, the round ligament, is found in females
  • The processus vaginalis is a finger like protrusion of the peritoneal lining of the abdominal cavity. It accompanies the testicle and spermatic cord structures lying against the cord in the inguinal canal. Imagine a ball pushed into an inflated balloon. The ball or testicle is now covered with two layers of peritoneum. The processus vaginalis normally becomes fused from it's origin to the level of the 'balloon' around the testicle (Figure 3)
  • The spermatic cord (in males) contains the blood vessels and nerves that pass from the abdominal cavity into the scrotum. The scrotum is the sac of skin that holds the testicles
  • The internal inguinal ring is lateral (away from the midline) to the inferior epigastric artery and is the site where the cord penetrates the internal oblique muscle to lie in the inguinal canal (Figure 1)
  • The external inguinal ring is the opening in the external oblique muscle and fascia where the cord moves from the inguinal canal to the subcutaneous tissue to enter the scrotum
  • The inguinal ligament is the inferior tough fascia portion of the external oblique muscle that inserts on the anterior superior iliac spine of the pelvic bone and has a free border going medially (towards the midline) until it attaches to the pubic tubercle
  • The ilioinguinal nerve lies on the internal oblique muscle superior to the cord structures. The genitofemoral nerve lies usually behind and inferior to the mid cord structures. These nerves provide sensation to the groin and scrotum.
  • In the female, the round ligament of the uterus accompanies the processus vaginalis in the inguinal canal. The round ligament exits the inguinal canal at the external ring and inserts into the pubic tubercle
Figure 3 - Left. The processus vaginalis accompanies the testicle and spermatic cord structures lying against the cord in the inguinal canal. The testicle is covered with two layers of peritoneum. Right. The processus vaginalis normally becomes fused from it's origin to the level of the tunica vaginalis.© C. Salici

Pathology

  • The groin is one of the natural weak areas in the abdominal wall. It is the most common site for abdominal herniation
  • Failure of fusion of the processus vaginalis from the abdominal peritoneum to the upper level of the testicle, before birth, results in an open sac communicating with the abdominal cavity
    1. The sac may be open for a short distance, inguinal hernia (Figure 4, left); or communicate with the portion surrounding the testicle, scrotal hernia (Figure 4, right)
    2. The portion of the processus vaginalis surrounding the testicle does not fuse normally
    3. If the entire processus vaginalis remains open, abdominal fluid can collect around the testicle resulting in a communicating hydrocele (Figure 5, left)
    4. The hernia sac (processus vaginalis) may become isolated into small collections of fluid (male-hydrocele of the cord (Figure 5,center), female-cyst of the canal of Nuck)
    5. In the female, the ovary or tube may be pulled into the processus vaginalis along side the round ligament to make up one side of the hernia sac (sliding hernia)
    6. It is unusual to have an isolated hydrocele (fluid in sac enveloping the testicle) in children (hydrocele of tunica vaginalis) (Figure 5, right)
    7. The appendix may occasionally be part of a sliding hernia
  • The major concern with inguinal hernias is incarceration (inability to return hernial sac contents to the abdominal cavity) progressing to strangulation (gangrene of the structures due to compromise of the blood supply) of the contents
  • There is concern about torsion (twisting with loss of blood supply) of undescended testicles in males or torsion of the ovary or tube in sliding female hernias
  • Indirect inguinal hernias occur when the hernia sac is lateral to the inferior epigastric artery (most common). Direct inguinal hernias are present when the sac is medial to the inferior epigastric artery
Figure 4 - The sac may be open for a short distance (left) or communicate with the portion surrounding the testicle (right). © C. Salici
Figure 5 - The entire processus vaginalis may remain open and abdominal fluid collect around the testicle (left); the sac may become isolated into a small collection of fluid (center) or the fluid in the sac may envelope the testicle (right). © C. Salici

History and Physical Exam

  • Usually a small mass is noted in the groin area
  • The mass may vary in the way it presents and size because fluid or sac contents are able to return to the abdominal cavity spontaneously
  • A fretful crying baby is unable to tell a parent that he/she has a tender mass in the groin
  • The parent or examiner may be able to gently reduce the mass back into the abdomen. If the mass is not present when the surgeon examines the baby, the surgeon is frequently unable to reproduce the mass. Surgery is often performed on the parent's conviction that a previous mass existed
  • Physical examination may be entirely normal
  • Examination is the most important evaluation. Groin evaluation is difficult because of the relative amount of fatty tissue in the groin
  • A careful examination of both groins is performed to identify a groin mass and whether it contains abdominal contents
  • The scrotum is examined carefully to determine the presence of both testicles. An undescended testicle may be present with the hernia or present without a hernia
  • Efforts to feel an ovary or tube in the groin is performed in females
  • Premature, preterm and underweight babies have a higher incidence of inguinal hernias and they are frequently bilateral
  • Associated anomalies are not increased in inguinal hernia babies
  • If a baby is unusually distressed or crying forcefully and cannot be consoled, the baby may have an incarcerated hernia

Tests

  • The diagnosis of inguinal hernia is usually a clinical exam
  • It is unusual to do herniography (dye injected into abdominal cavity with X-ray to see if a hernia sac is present)
  • Plain X-rays may show gas or mass effect in the groin area
  • CT scan or MRI studies are rarely indicated
  • Ultrasound may be helpful in diagnosing a mass or fluid in the groin

Indications for Surgery

  • All pediatric inguinal hernias require surgery when the baby can tolerate surgery without undue risk
  • Because of increases in pressure within the abdomen with crying and moving, most hernias will not disappear without surgery

Surgical Procedure

  • Surgery may be performed under general or local anesthesia. The typical inguinal male hernia repair is as follows:
    1. A small incision of about one inch is made in the skin above the groin crease (Figure 6)
    2. The subcutaneous fatty tissue is divided to expose the external oblique fascia
    3. A small incision in the external oblique fascia is made just above the inguinal ligament to the external inguinal ring or opening of external inguinal ring
    4. The hernia sac is picked up along side the internal inguinal ring, mobilized (separated from surrounding tissues) and ligated (tied off) high with excision of the sac. (Figure 7 and 8) Sometimes the cord and contents are mobilized and retracted with dissection of the sac away from cord with high ligation and excision of the sac
    5. The inguinal floor is usually not reinforced with sutures
    6. A long sac may extend down to the testicle with an open processus vaginalis. The sac is then excised to the upper edge of the testicle with preservation of the processus vaginalis covering the testicle
    7. The incised external oblique muscle layer and subcutaneous tissue are closed with sutures
    8. The skin is closed with absorbable sutures that do not need to be removed or with non-absorbable suture that have to be subsequently removed (Figure 9)
  • Repair in the female is done in a similar fashion except for treatment of the sliding ovary or tube
    1. The hernia sac is mobilized away from the round ligament
    2. The sac is opened and the tube and ovary returned to the peritoneal cavity with over sewing of the remaining sac
    3. The round ligament may be sacrificed
    4. Wound closure is the same as in the male
  • Any hernia sac that contained abdominal contents or bloody fluid is opened and the contents inspected for to be sure the tissue has a good blood supply
  • If the testicle is mobilized or exposed during the operation, careful attention is given to replacing it in the scrotum without any twisting
  • If an incarcerated hernia contains strangulated bowel, the abnormal bowel is removed and the ends anastomosed (sewn together) to reestablish intestinal continuity
  • Undescended testicles would be mobilized and fixed in the scrotum
  • Some surgeons consider exploring the opposite side because of the higher incidence of bilateral hernias in very small babies
  • There is always concern about a hernia becoming an incarcerated hernia progressing to strangulation
Figure 6 - Incision for hernia repair. © C. SaliciFigure 7 - The wound is opened and the hernia sac exposed. © C. Salici
Figure 8 - Excess sac is tied off. © C. SaliciFigure 9 - The muscle layers and skin are closed. © C. Salici

Complications

  • Bleeding
  • Infection - wound, lungs, urinary tract
  • Constipation
  • Torsion (twisting) of a testicle
  • Testicle atrophy - shrinkage of testicle usually due to decreased blood supply
  • Viability of the testicle if undescended
  • Problem with a bowel anastomosis - fistula (leak or break down of suture line), viability, intestinal obstruction
  • Gastric retention - excess gas in stomach, vomiting
  • Recurrent hernia - rare

Post Operative Care

  • Most inguinal hernias will be repaired on an outpatient basis
  • The child is not fed for 4-6 hours after surgery. If stable, the child is then started on clear liquids and progressed to a regular pediatric diet
  • The incision site is inspected regularly
  • Urination and bowel activity is noted
  • Pain medication is usually unnecessary
  • Activity is as tolerated
  • Bathe normally
  • Suture removal in 5-7 days if non absorbable skin suture is used
  • If bowel resection is required then the infant is hospitalized
    1. A tube is placed through the nose into the stomach to reduce stomach pressure
    2. Fluid is given by vein
    3. Antibiotics may be given for 3-4 days
    4. When bowel function returns to normal the tube is removed and feeding begun
    5. Hospital stay is about 5-7 days

After Care

  • There is usually a one time office visit for suture removal and wound inspection for an uncomplicated inguinal herniorraphy
  • The parents are instructed to observe the opposite side for presence of a hernia
  • Routine visits with the pediatrician

Femoral Hernia

Anatomy

  • The abdominal wall in the groin area is made up of different structures going from deepest to superficial layers (Figure 2):
    1. Peritoneum - the lining of the abdominal cavity (becomes the hernia sac)
    2. Subperitoneal fat - fat beneath the peritoneum
    3. Transversalis fascia - sheet of fibrous tissue that envelops the peritoneum
    4. Transversus abdominis muscle
    5. Internal oblique muscle
    6. External oblique muscle
    7. Subcutaneous fat
    8. Skin
  • The three muscles layers overlap each other in the groin area but do not attach to any structures going into the lower extremity. Man is the only mammal to have groin hernias because of his upright posture
  • The inguinal ligament is the inferior tough fascia portion of the external oblique muscle that inserts on the anterior superior iliac spine of the pelvic bone and has a free border going medially (towards the midline) until it attaches to the pubic tubercle
  • The area immediately underneath the inguinal ligament contains from lateral to medial the femoral nerve, femoral artery, femoral vein, empty space and femoral lymphatics (NAVEL). A femoral hernia protrudes through the empty space

Pathology

  • The peritoneum is pushed under the inguinal ligament through the empty space into the upper thigh below the inguinal crease (Figure 10)
  • The peritoneum also pushes the transversalis fascia with it underneath the inguinal ligament
  • No abdominal wall muscle covers the peritoneal protrusion
  • The thigh skin, subcutaneous tissue and deep fascia (membranous tissue that encircles the thigh muscles) overlie the protruding peritoneal sac and transversalis fascia that lies just below the groin crease
  • Though the hernia sac opening is usually very small, abdominal contents (usually bowel or part of bowel wall) may be in the sac
Figure 10 - A small incision is made in the fascia just above inguinal ligament to the external inguinal ring. The internal oblique and transversis abdominis muscles are moved upward as are the cord structures. © C. Salici

History and Exam

  • Typically a parent or examiner finds a mass just beneath the inguinal ligament
  • The mass may be intermittent in nature, but will often times be felt when the child is crying
  • Abdominal contents may become pinched in the hernia sac and precipitate more severe crying
  • Observation is the important factor in making the diagnosis
  • Careful examination of both groins is also performed
  • The mass may not be felt by the pediatrician or surgeon
  • On clinical exam, it is frequently difficult to distinguish between an inguinal or femoral hernia. A surgeon who operates for an inguinal hernia and doesn't find one will look carefully for a femoral hernia

Tests

  • Clinical examination alone is usually enough in most cases
  • Ultrasound scan may be helpful in identifying a mass in the groin

Surgical Procedure

  • Surgery for femoral hernia is similar to inguinal hernia surgery
  • Femoral hernia surgery is performed when there are no contraindications to surgery. The presence of a tender groin mass warrants urgent surgery to avoid incarcerated (unable to be reduced) contents progressing to strangulation (dead tissue)
  • Surgery may be performed under general or local anesthesia on an outpatient basis
  • The typical femoral hernia repair is as follows:
    1. A small one inch groin incision is made above the groin crease (Figure 6)
    2. The subcutaneous fatty tissue is divided to expose the underlying external oblique fascia and a small incision made in the fascia just above inguinal ligament to the external inguinal ring
    3. The internal oblique and transversis abdominis muscles are retracted (moved) superiorly (towards the head) and the cord structures in the male or round ligament in the female retracted superiorly (Figure 10)
    4. A search is made for a narrow protruding tissue mass (transversalis fascia and peritoneum - the neck of the hernia) in the empty space of the femoral canal
    5. The sac is identified and passed upward underneath the inguinal ligament and opened for inspection by opening the transversalis fascia and peritoneum. The goal is to reduce the sac underneath the inguinal ligament without dividing the ligament (Figure 11)
    6. The hernia sac is ligated at its neck and excised (removed) (Figure12)
    7. The transversalis fascia is sutured and the empty space narrowed by suturing the part of the inguinal ligament near the midline to the ileopectineal line (back ridge of pubic bone) without narrowing the femoral vein
    8. The spermatic cord or round ligament is returned to its normal position
    9. The cut external oblique fascia, subcutaneous tissue and skin are sutured (Figure 9)
    10. Any hernia sac that contains abdominal contents or bloody fluid is opened wider and the contents inspected for viability. If an incarcerated hernia contains strangulated bowel, the bowel is resected (cut out) and the ends anastomosed (sewn together) to reestablish continuity of the bowel
Figure 11 - The sac is passed upward underneath the inguinal ligament and opened for inspection. © C. SaliciFigure 12 - The hernia sac is ligated at its neck and removed.© C. Salici

Complications

  • Bleeding
  • Skin necrosis (death)
  • Infection of the wound, lungs or urinary tract
  • Constipation
  • Adhesions with possible bowel obstruction if bowel is trapped in the hernia sac and extensive dissection required to mobilize the bowel
  • With bowel anastomosis there may be a fistula (leak or break down of the suture line), loss of viability or obstruction of the bowel
  • Excess gas in the stomach that may cause vomiting
  • Recurrent hernia - rare

Post Operative Care

  • Most inguinal hernias will be repaired on an outpatient basis
  • The child is not fed for 4-6 hours after surgery. If stable, the child is then started on clear liquids and progressed to a regular pediatric diet
  • The incision site is inspected regularly
  • Urination and bowel activity is noted
  • Pain medication is usually unnecessary
  • Activity is as tolerated
  • Bathe normally
  • Suture removal in 5-7 days if non absorbable skin suture is used
  • If bowel resection is required then the infant is hospitalized
    1. A tube is placed through the nose into the stomach to reduce stomach pressure
    2. Fluid is given by vein
    3. Antibiotics may be given for 3-4 days
    4. When bowel function returns to normal the tube is removed and feeding begun
    5. Hospital stay is about 5-7 day

After Care

  • There is usually a one time office visit for suture removal and wound inspection for an uncomplicated inguinal herniorraphy
  • The parents are instructed to observe the opposite side for presence of a hernia
  • Routine visits with the pediatricia

Umbilical Hernia

Anatomy

  • The mid abdominal wall is composed of two large muscles (rectus abdominis) that run up and down and originate from the rib cage above and insert into the pubic bone below (Figure 13)
  • The upper 3/4 of the rectus muscles are covered by a tough fascial sheath that lies in front and behind the muscles (Figure 14)
  • The lower ¼ of the rectus muscles has only a tough sheath in front of the muscle
  • The lateral abdominal wall muscles - external oblique, internal oblique and transverses abdominis muscles contribute to the sheath
  • The muscle sheaths meet in a midline band called the linea alba
  • Just below the middle of the linea alba is an opening called the umbilical ring where the umbilical cord entered the fetus (Figure 15)
Figure 13 - Anatomy of the front wall of the abdomen. © C. Salici
Figure 14 - Anatomy of the front wall of the abdomen as seen from above. Note the various muscles (m) and fascia. © C. Salici
Figure 15 - Midline anatomy of the front wall of the abdomen seen from the side (the rectus abdominis muscle is actually just off the midline). © C. Salici

Pathology

  • The umbilical hernia consists of an enlarged umbilical ring in the linea alba with peritoneum herniating outside the abdominal cavity (Figure 16)
    1. The peritoneum or hernia sac is only covered by skin
    2. Abdominal contents may be present in the hernia sac
  • At the child grows the rectus abdominis muscles become stronger and tend to pull together in the midline. This pulling together reduces the force on the edges of the umbilical ring and the defect gradually closes to a fingertip size. Defects larger than two centimeters at birth will not always close
Figure 16 - Umbilical hernia containing a loop of bowel. © C. Salici

History and Exam

  • A persistent or enlarging abdominal mass is noted at the umbilicus
  • On examination the mass at the umbilicus can be reduced (pushed back into the abdomen)
  • The tough sheath edges of the defect are easily felt

Tests

  • Clinical examination alone is usually enough in most cases

Surgical Procedure

Defects greater than 1-2 centimeters after 3-4 years of age will usually require repair

  • It is unusual for pediatric umbilical hernias to incarcerate but emergency repair will be necessary urgently if any abdominal contents become incarcerated in the sac
  • Repair is usually carried out under general or local anesthesia on an outpatient basis
  • Repair is as follows:
    1. A small incision is made on the under side of the hernia (Figure 17)
    2. The hernia sac is separated from the overlying skin and any bowel returned to the abdominal cavity (Figures 18 and 19)
    3. The base of the sac is ligated and excess sac removed (Figure 20)
    4. The linea alba is closed with sutures and the skin closed over the repair (Figure 21)
Figure 17 - Position of the incision for correcting an umbilical hernia. © C. Salici Figure 18 - Peritoneal sac opened to expose the bowel. © C. Salici
Figure 19 - The bowel is replaced into the abdominal cavity. © C. SaliciFigure 20 - Excess sac is removed and the peritoneum closed with suture. © C. Salici
Figure 21 - The linea alba is sutured together over the peritoneum. © C. Salici

Complications

  • Bleeding
  • Skin necrosis (death)
  • Infection of the wound, lungs or urinary tract
  • Constipation
  • Adhesions with possible bowel obstruction if bowel is trapped in the hernia sac and extensive dissection required to mobilize the bowel
  • With bowel anastomosis there may be a fistula (leak or break down of the suture line), loss of viability or obstruction of the bowel
  • Excess gas in the stomach that may cause vomiting
  • Recurrent hernia - rare

Post Operative Care

  • Most inguinal hernias will be repaired on an outpatient basis
  • The child is not fed for 4-6 hours after surgery. If stable, the child is then started on clear liquids and progressed to a regular pediatric diet
  • The incision site is inspected regularly
  • Urination and bowel activity is noted
  • Pain medication is usually unnecessary
  • Activity is as tolerated
  • Bathe normally
  • Suture removal in 5-7 days if non absorbable skin suture is used
  • If bowel resection is required then the infant is hospitalized
    1. A tube is placed through the nose into the stomach to reduce stomach pressure
    2. Fluid is given by vein
    3. Antibiotics may be given for 3-4 days
    4. When bowel function returns to normal the tube is removed and feeding begun
    5. Hospital stay is about 5-7 days

After Care

  • There is usually a one time office visit for suture removal and wound inspection for an uncomplicated inguinal herniorraphy
  • The parents are instructed to observe the opposite side for presence of a hernia
  • Routine visits with the pediatrician