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 {add more description}. The patient was referred to a pediatric surgeon, and she had a benign clinical course after primary repair of the defect.

Case Image

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

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).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    16. Learning of students and other health care professionals is facilitated.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • S/Q saline injection for pediatric art lines placed with POCUS guidance?

    I was catching up on back issues of Anesthesia & Analgesia when I came across this article from the May 2014 issue: Nakayama et al. A novel method for ultrasound-guided radial arterial catheterization in pediatric patient.

    This was actually 2 studies in 1, or 2 phases as the authors call it.

    Common features of both phases

    • Enrolled kids < 3 y.o. undergoing elective surgery who needed an art line pre-op
    • Performed in Kyoto, Japan
    • All lines placed by 2 anesthesiologists with lots of experience placing U/S-guided art lines
    • All lines placed using out-of-plane/short axis approach and real-time/dynamic technique without a guidewire

    Assessment phase
    102 patients enrolled

    Results: a radial artery that was more shallow than 2 mm or deeper than 4 mm were independent predictors of both decreased first-attempt and overall success.
    A depth 2-4 mm had the best success rate.
    Overall success rates:

    • < 2 mm: 62.5%
    • 2-4 mm: 89.7%
    • >4 mm: 51.6%

    Validation phase

    Methods
    With the results of the assessment phase known, the authors tested the hypothesis that a S/Q injection of saline to increase the arterial depth from < 2 mm to 2-4 mm would improve the success rate.
    60 patients were enrolled and had an art line placed. These were broken down into the following groups:

    • 20 had an arterial depth of 2-4 mm
    • 20 had an arterial depth of < 2 mm
    • 20 had an arterial depth of < 2 mm and had a S/Q injection of saline (< 2 mL)

    The last 2 groups were randomized. Measurement of depth, injection of saline, and marking of the appropriate insertion point was performed by an anesthesiologist other than the two who placed the art lines. These two anesthesiologists were also blinded to the results of the assessment phase.

    Results
    Success rate and time to catheterization improved significantly with the saline injection and no longer differed significantly from patients who initially presented with arteries located at a 2-4 mm depth
    Overall success rates:

    • 2-4 mm: 85.0%
    • < 2 mm: 55.0%
    • < 2 mm PLUS saline: 90.0%

    The authors hypothesized that an artery more shallow than 2 mm did not allow one to adjust the aim of the needle towards to the centre of the artery, simply because there is not enough trajectory to evaluate. They also suggested that a depth greater than 4 mm necessitated a needle angle that was too steep to allow easy cannulation. The injection of saline may also provide a better window to his very superficial structure, similar to an external step-off.

    One last tidbit from the authors explaining why technique is so important: a 24-gauge catheter has an outside diameter of 7 mm while the mean diameter of radial arteries in this study was 10 mm.

    Another question generated by this study: can a S/Q injection of saline improve the view of other superficial structures?

    Episode 15 – Atrial Fibrillation/Flutter

    (iTunes or listen here) The Free Open Access Medical Education (FOAM) This week we review a post from Academic Life in Emergency Medicine, written by Brent Reed on selecting rate control agents in the management of atrial fibrillation.  This is a follow up post to Bryan Hayes’ summary of emergency department (ED) management of acute atrial fibrillation. […]

    Figure 1 Image of the Week #4

    A 6 year old male presents with swelling over the midline of the neck for the past 2 days. The swelling is non tender and moves with swallowing. What is the diagnosis?


     

    Pondering.

     

    Answer.


    Image of the Week - Thyroglossal Duct Cyst


    This patient has a Thyroglossal Duct Cyst. These cysts often form in 
    childhood and are caused by cystic expansion of the remnant of the tract 
    that forms as the thyroid gland descends from the tongue base to the 
    neck. Often, these cysts are small, asymptomatic, and go untreated.

    Location is key in pediatric neck masses

    Location is key in pediatric neck masses

    See more cases like this on Figure 1

    Photo credit: Figure 1 Medical Images/Abdul Mukaddem Mashud


    Resources:

    [BLOG} Neck Masses in Children at Pediatric Focus.

    [REVIEW] Pediatric Neck Masses

    Figure 1 Image of the Week #4

    A 6 year old male presents with swelling over the midline of the neck for the past 2 days. The swelling is non tender and moves with swallowing. What is the diagnosis?


     

    Pondering.

     

    Answer.


    Image of the Week - Thyroglossal Duct Cyst


    This patient has a Thyroglossal Duct Cyst. These cysts often form in 
    childhood and are caused by cystic expansion of the remnant of the tract 
    that forms as the thyroid gland descends from the tongue base to the 
    neck. Often, these cysts are small, asymptomatic, and go untreated.

    Location is key in pediatric neck masses

    Location is key in pediatric neck masses

    See more cases like this on Figure 1

    Photo credit: Figure 1 Medical Images/Abdul Mukaddem Mashud


    Resources:

    [BLOG} Neck Masses in Children at Pediatric Focus.

    [REVIEW] Pediatric Neck Masses