What is the principle of hernia repair?

Principles of Hernia Repair

The fundamental principle of hernia repair is tension-free closure of the fascial defect using prosthetic mesh reinforcement, which significantly reduces recurrence rates compared to primary tissue repair without increasing infection risk. 1

Core Surgical Principles

The basic technical approach involves four essential steps 2:

• Identify and isolate the hernia sac from surrounding tissues 2
• Reduce the herniated contents back into the abdominal cavity, assessing viability of any incarcerated organs 1
• Locate the hernia ring/defect in the abdominal wall 2
• Repair the fascial defect with appropriate reinforcement 2

Tension-Free Mesh Repair as Standard

Prosthetic mesh repair is recommended as the first-choice technique for hernia repair, representing a paradigm shift from historical tension-based tissue repairs. 3

• Mesh reinforcement reduces recurrence rates to 0-3% compared to 10-35% with primary tissue repair 1, 3
• Synthetic mesh provides durable reinforcement without increasing wound infection rates in clean surgical fields (CDC Class I) 1
• The mesh should overlap the defect edges by at least 5 cm to prevent recurrence 1, 4
• Proper mesh fixation to the defect edges is critical, though in certain laparoscopic repairs (TEP), fixation may be unnecessary except for large medial hernias 3

Stratification by Wound Contamination

The World Journal of Emergency Surgery guidelines stratify repair technique based on CDC wound classification 1:

Clean Fields (CDC Class I)

• Use synthetic mesh for all repairs when no bowel compromise exists 1
• This applies to elective repairs and incarcerated hernias without strangulation 1

Clean-Contaminated Fields (CDC Class II)

• Synthetic mesh can still be safely used when bowel resection is required without gross spillage 1
• This approach significantly lowers recurrence risk without increasing 30-day wound morbidity 1

Contaminated/Dirty Fields (CDC Class III-IV)

• Primary tissue repair is recommended for defects <3 cm 1
• When direct closure is not feasible, biological mesh or polyglactin mesh should be used instead of synthetic materials 1, 4
• The choice between cross-linked and non-cross-linked biological mesh depends on defect size and contamination degree 1

Surgical Approach Selection

Laparoscopic repair is the preferred technique in hemodynamically stable patients without significant comorbidities, offering faster recovery, lower chronic pain rates, and cost-effectiveness 1, 3:

• Laparoscopic approaches (TAPP, TEP) facilitate early diagnosis of small defects and reduce postoperative complications 1, 3
• Open surgery is reserved for unstable patients, when laparoscopic expertise/equipment is unavailable, or when exploratory laparotomy is needed 1
• For recurrent hernias: if the initial repair was anterior, use a posterior approach for the recurrence, and vice versa 3

Critical Technical Considerations

Nerve management in open repair is essential to prevent chronic postoperative inguinal pain (CPIP) 3:

• Surgeons should recognize nerves during dissection 3
• In selected cases, prophylactic pragmatic nerve resection may be considered, though planned resection is not routinely suggested 3

Mesh characteristics matter beyond just weight 3:

• Low-weight mesh may provide slight short-term benefits (reduced pain, shorter convalescence) but shows no long-term advantage in recurrence or chronic pain 3
• Avoid plug repair techniques due to higher erosion rates compared to flat mesh 3

Emergency Repair Principles

Immediate surgical intervention is mandatory when intestinal strangulation is suspected 1, 5:

• Systemic inflammatory response syndrome, contrast-enhanced CT findings, and elevated lactate/CPK/D-dimer predict bowel strangulation 1, 5
• Diagnostic laparoscopy may be useful to assess bowel viability after spontaneous reduction of strangulated hernias 1, 5
• In unstable patients with severe sepsis/septic shock, open management with damage control surgery prevents abdominal compartment syndrome 1

Anesthesia Selection

Local anesthesia is recommended for emergency hernia repair when bowel gangrene is absent, providing effective anesthesia with fewer postoperative complications, shorter hospital stays, lower costs, and faster recovery 1, 5:

• General anesthesia should be used when bowel gangrene is suspected, intestinal resection is needed, or peritonitis is present 1, 5
• For patients ≥65 years, general anesthesia may be preferred over regional due to lower rates of myocardial infarction, pneumonia, and thromboembolism 3

Common Pitfalls to Avoid

• Insufficient mesh overlap (<5 cm) leads to recurrence through failure of the host-prosthesis interface 1
• Using synthetic mesh in contaminated fields risks mesh infection and removal 1
• Inadequate assessment of bowel viability in incarcerated hernias can result in missed necrosis and subsequent perforation 1
• Excessive tension on tissue repairs causes early failure and high recurrence rates 3