Hernias

Quick Overview

Hernias represent protrusions of viscera through fascial defects and are among the most common surgical conditions. Inguinal hernias (indirect/direct) account for 75% of abdominal wall hernias, followed by femoral (3%), umbilical (10%), and incisional (10%). Recognition of strangulation (irreducible with vascular compromise) is critical-it constitutes a surgical emergency requiring intervention within 6 hours to prevent bowel necrosis.

Core Facts & Concepts

Anatomical Classification & Landmarks

📌 Remember: NAVEL - Nerve, Artery, Vein, Empty space (femoral canal), Lymphatics (lateral to medial in femoral triangle)

Emergency Presentations

• Incarceration: Irreducible hernia without vascular compromise (contents trapped but viable)
• Strangulation: Vascular compromise → ischaemia within 6 hours
  • 🚩 Red flags: Severe pain, fever, tachycardia, tender/erythematous overlying skin, absent bowel sounds
  • Mortality: 5-8% if bowel resection required

NICE NG104 Repair Indications

• Mesh repair: Standard for inguinal hernias (recurrence 2-4% vs 10-15% non-mesh)
• Non-mesh (tissue) repair: Contaminated fields, patient preference after counselling
• Watchful waiting: Asymptomatic/minimally symptomatic inguinal hernias acceptable if patient informed of risks
  • Not suitable for femoral hernias (high strangulation risk: 40% within 2 years)

Problem-Solving Approach

Clinical Assessment Pathway

1. Position patient: Examine standing and supine; ask patient to cough
2. Palpate deep ring: Reduce hernia, occlude deep ring (mid-inguinal point), ask to cough
   • Controlled = indirect; not controlled = direct
3. Assess reducibility: Gentle taxis with patient supine, hips flexed
4. Evaluate for strangulation: Check skin changes, tenderness, systemic signs

Emergency Management

• Strangulated hernia: NBM, IV access, analgesia, emergency surgery within 6 hours
• Incarcerated but not strangulated: Trial of reduction (analgesia + Trendelenburg position)
  • If unsuccessful after 30 minutes → urgent surgery (within 24 hours)

⚠️ Warning: Never attempt prolonged forceful reduction-risk of reducing necrotic bowel into abdomen ("reduction en masse")

Analysis Framework

Differential Diagnosis: Groin Lump

Decision Rule: Surgical Urgency

• Immediate (<6h): Strangulation signs present
• Urgent (<24h): Irreducible without strangulation signs
• Elective: Symptomatic reducible hernias
• Watchful waiting: Asymptomatic inguinal only (NOT femoral)

Visual Aid

Risk Factors for Incisional Hernias

• Surgical: Midline incisions (10-15%), wound infection, emergency surgery
• Patient: Obesity (BMI >30), smoking, diabetes, chronic cough, ascites
• 📊 Incidence: 10-15% at 2 years post-laparotomy

Key Points Summary

✓ Anatomical distinction: Indirect (lateral to inferior epigastric vessels), direct (medial), femoral (below inguinal ligament, high strangulation risk 40%)

✓ Strangulation = emergency: Requires surgery within 6 hours; red flags include pain, fever, skin changes, irreducibility

✓ NICE NG104: Mesh repair standard (recurrence 2-4%); watchful waiting acceptable for asymptomatic inguinal hernias only-never for femoral

✓ Femoral hernias: Always require repair due to 40% strangulation risk within 2 years; commonest in elderly women

✓ Examination technique: Assess standing and supine with cough impulse; occlude deep ring to differentiate direct vs indirect

✓ Incisional hernia prevention: Optimize BMI, smoking cessation, glycaemic control pre-operatively

✓ Never force reduction: Risk of reducing necrotic bowel ("reduction en masse")-if unsuccessful after 30 minutes with analgesia, proceed to surgery