What Types of Abdominal Wall Defects Are There?

Patient Presentation

A 5-year-old female came to clinic for her health supervision visit. She was well but the father wanted to address “her other belly button.” The parent said that sometimes there was bulge above her umbilicus but it was not consistent. She denied any pain or problems because of it. The past medical history revealed a well child who had a previously diagnosed umbilical hernia.

The pertinent physical exam showed a well child with normal vital signs and growth parameters in the 75-90%. Her abdominal examination showed a soft non-tender abdomen without organomegaly or masses. Her umbilicus was normal, but 3 cm above the umbilicus there was a skin protuberance when the patient valsalved. Palpation of the area showed an obvious skin lesion, and a midline fingertip-sized, round area. It had a distinct ridge between 4-8 o’clock, but was much thinner in the other areas. It was unclear if there was a distinct annulus. The area had a feeling of serosa moving over something else. The diagnosis of a ventral wall defect was made but the pediatrician was unsure exactly what it was. One of her experienced partners also wasn’t exactly sure. The radiologic evaluation of an ultrasound showed an epigastric hernia. The patient was referred to a pediatric surgeon, and she had a benign clinical course after primary repair of the defect.

Figure 116 – Transverse image from an ultrasound exam of the midline abdominal wall just superior to the umbilicus shows something – perhaps omental fat – herniating in the midline between the medial rectus muscles which should normally be joined together in the midline.

Discussion
Abdominal wall defects are common in pediatric and adult patients. Pediatric patients not surprisingly have more congenital defects and adults have more that are spontaneously acquired and some are due to surgeries. Adults often have more complications of their defects also. Defects are usually classified by location.

Learning Point

Types of abdominal wall defects include:

• Congenital or Spontaneous
  • Epigastric
    • Rectus muscles fail to approximate at the linea alba between the umbilicus and xyphoid process. Usually presents as painless bulge
    • Occurs to 5% of children
    • Incarceration is uncommon in children but much more common in adults
    • Usually repaired
  • Umbilical hernia
    • Umbilicus fails to close in first weeks of infancy
    • Occurs in 10-20% of children
    • Usually close by 2-3 years
    • Incarceration and strangulation are rare in children but more common in adults.
    • Repair usually around 3-5 years
    • For more information about umbilical hernias, click here.
    • For a differential diagnosis of umbilical masses, click here.
  • Groin hernia – inguinal and femoral hernias
    • Inguinal hernias occurs in about 1-5% of infants and femoral hernias occur in < 1%
    • Most inguinal hernias are indirect (i.e. the hernia passes through the internal inguinal ring and down the inguinal canal); only 2% of all hernias in children are direct hernias (i.e. the hernia directly protrudes through the floor of the inguinal canal).
    • Incarceration and strangulation are common
    • These will not close and need repair
    • For more information about inguinal hernias, click here.
  • Gastroschisis and omphalocoele
    • Viscera protrudes through a central abdominal wall defect that is covered (omphalocoele) or uncovered (gastroschisis) with an overlying sac.
    • Gastroschisis usually is lateral to umbilicus and omphalocoele is centered over the umbilicus
    • Occurs in 2-3 in 10,000
    • All need repair and are potentially life-threatening emergencies
  • Spigelian
    • Bulge along lateral rectus below the umbilicus due to defect in the semi-lunar line of the posterior rectus sheath.
    • Rare
    • Incarceration occurs
    • Needs to be repaired
• Surgical complications
  • Incisional hernia
    • Caused by failure of fascia to heal after abdominal incision. Presents as bulge at incisional site
    • 10-15% of patients
    • Can occur early after surgery or late (> 10 years)
    • Problems include incarceration and complicating activities of daily living and cosmesis
    • Most need repair
  • Parastomal hernia
    • Failure to heal(gastroschisis) after creation of the abdominal stoma. Presents as a bulge at site
    • Most need repair
• Other
  • Lumbar hernia
    • Technically outside the abdomen but is usually classified as an abdominal wall hernia.
    • Area of hernia is below 12th rib, lateral of erector spinae muscle, super to iliac crest, media to the external oblique muscle.
    • Etiology is unclear in children but usually a surgical complication in adults
  • Sciatic hernia
    • Herniation through the greater sciatic foramen
    • Rare
    • Needs repair
  • Diastasis recti
    • Technically not a hernia. The recti muscles are stretched and separated laterally giving the appearance of an abdominal wall defect but there is no fascial defect.
    • Often due to obesity or pregnancy.

Questions for Further Discussion
1. Some surgical repairs are made with mesh material. What are the advantages and disadvantages of mesh material?
2. What radiological imaging techniques are helpful for discerning the anatomy of abdominal wall defects?

Related Cases

Disease: Epigastric Hernia | Hernia

Symptom/Presentation: Mass or Swelling | Abdominal Mass

Specialty: Surgery |
Radiology / Nuclear Medicine / Radiation Oncology

Age: School Ager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Hernia.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Kelly KB, Ponsky TA. Pediatric abdominal wall defects. Surg Clin North Am. 2013 Oct;93(5):1255-67.

Brooks DC. Overview of Abdominal Hernias. Up To Date. (rev. 10/9/12, cited 6/26/14).

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