Hernia: Abdominal Wall and Groin

Introduction to Hernias for MCCQE1

A hernia is defined as the protrusion of an organ or fascia of an organ through the wall of the cavity that normally contains it. For the MCCQE1, understanding abdominal wall and groin hernias is crucial as they represent a significant portion of general surgery presentations in Canada.

Candidates must demonstrate the ability to diagnose based on physical exam, identify surgical emergencies (strangulation), and understand the Canadian context of surgical management (e.g., wait times, Choosing Wisely guidelines).

Anatomical Abbreviations

IHR  : Inguinal Hernia Repair
TAPP : Transabdominal Preperitoneal (Laparoscopic)
TEP  : Total Extraperitoneal (Laparoscopic)
IEA  : Inferior Epigastric Artery

Classification and Anatomy

Understanding the anatomy is essential for differentiating hernia types. The relationship to the Inferior Epigastric Artery (IEA) is the primary anatomical landmark for distinguishing inguinal hernias.

Hesselbach’s Triangle Boundaries

1. Lateral: Inferior Epigastric Vessels
2. Medial: Rectus Abdominis Muscle (lateral border)
3. Inferior: Inguinal Ligament (Poupart’s ligament)

Clinical Presentation and Complications

The clinical status of the hernia dictates the urgency of management.

Diagnostic Approach

Physical Examination

Imaging Guidelines (Choosing Wisely Canada)

Routine imaging is not required for the diagnosis of a typical groin hernia if the physical exam is diagnostic.

• Ultrasound: First-line modality if the diagnosis is clinically equivocal (e.g., “groin pain” with no palpable lump).
• CT Scan: Indicated if complications are suspected (strangulation, bowel obstruction) or for complex incisional hernias to plan surgery.

Management Strategies

1. Conservative Management (Watchful Waiting)

• Indication: Minimally symptomatic or asymptomatic inguinal hernias in men.
• Rationale: Low risk of incarceration (<1% per year).
• Contraindication: Femoral hernias (always repair due to high strangulation risk) and symptomatic hernias.

2. Surgical Management

Surgery is the only curative treatment.

Indications for Surgery

• Symptomatic inguinal hernias (pain, discomfort affecting daily life).
• Femoral hernias (regardless of symptoms).
• Incarcerated or strangulated hernias (Emergency).
• Women with groin hernias (higher incidence of femoral hernias masked as inguinal).

Surgical Techniques

Pediatric Considerations

• Umbilical Hernia: Most close spontaneously by age 4-5. Repair indicated if defect persists >4-5 years old, is very large (>2cm), or becomes incarcerated.
• Inguinal Hernia: In children, this is almost always indirect (patent processus vaginalis). High risk of incarceration. Repair is indicated shortly after diagnosis (no watchful waiting).

Canadian Guidelines & Choosing Wisely

• Choosing Wisely Canada: Don’t order imaging for uncomplicated hernias that are evident on physical exam.
• Wait Times: In the Canadian public system, uncomplicated hernias are elective. Strangulated hernias are emergent (Code 1/A).
• Mesh Usage: Mesh repair is the gold standard in Canada for adults to reduce recurrence rates, except in contaminated fields (e.g., bowel resection due to strangulation) where biologic mesh or tissue repair (Shouldice) might be considered.

Key Points to Remember for MCCQE1

1. Strangulation is a clinical diagnosis requiring immediate surgical intervention; do not delay for imaging if signs are obvious.
2. Femoral hernias present as a lump below the inguinal ligament and have the highest risk of complications; repair is always recommended.
3. Indirect hernias are the most common type in both sexes.
4. Nerve Injury: The ilioinguinal nerve is most commonly injured during open inguinal hernia repair, causing numbness/pain in the medial thigh and scrotum/labia.
5. Pediatric Inguinal Hernias: Always require surgery (high incarceration risk). Pediatric Umbilical Hernias: Often observed until age 5.

Sample Question

Case Presentation

A 78-year-old female presents to the Emergency Department with a 6-hour history of severe right groin pain and vomiting. On examination, she is afebrile but tachycardic (HR 105 bpm). There is a tender, non-reducible, erythematous lump located inferior to the inguinal ligament in the right groin. The abdomen is distended with hyperactive bowel sounds.

Question

Which one of the following is the most appropriate next step in management?

• A. Attempt manual reduction with sedation
• B. Urgent ultrasound of the groin
• C. Elective referral to General Surgery
• D. Emergency surgical exploration
• E. CT scan of the abdomen and pelvis

Explanation

The correct answer is:

• D. Emergency surgical exploration

Detailed Explanation:

• Diagnosis: The clinical picture is classic for a strangulated femoral hernia. The patient is an elderly female (classic demographic), presenting with a tender, non-reducible lump below the inguinal ligament (anatomical location of femoral hernia), accompanied by signs of bowel obstruction (vomiting, distension, hyperactive bowel sounds) and strangulation (erythema, tachycardia, severe pain).
• Management: Strangulation implies compromised blood supply to the bowel. This is a surgical emergency. Immediate surgical exploration is required to release the hernia and assess bowel viability.
• Why other options are incorrect:
  • A (Manual reduction): Contraindicated in cases of suspected strangulation as it may push necrotic bowel back into the peritoneal cavity (reduction en masse) or rupture the friable bowel.
  • B (Ultrasound): While ultrasound can diagnose hernias, this patient has clinical signs of a surgical emergency. Imaging delays definitive treatment.
  • C (Elective referral): This is an emergency, not an elective case.
  • E (CT scan): While a CT might confirm the diagnosis, in a patient with clear clinical signs of strangulated hernia and bowel obstruction, delaying for a CT scan is unnecessary and potentially harmful. If the diagnosis were unclear, CT would be the imaging of choice, but surgical consultation/intervention takes precedence here.

References

1. HerniaSurge Group. International guidelines for groin hernia management. Hernia. 2018;22(1):1-165. doi:10.1007/s10029-017-1668-x.
2. Choosing Wisely Canada. General Surgery: Five Things Physicians and Patients Should Question. Available at: https://choosingwiselycanada.org/general-surgery/ 
3. Medical Council of Canada. MCCQE Part I Clinical Decision-Making and Multiple-Choice Question Objectives.
4. Townsend CM, et al. Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 21st ed. Philadelphia, PA: Elsevier; 2022.
5. Royal College of Physicians and Surgeons of Canada. CanMEDS Framework.