Which layers should be debrided when an abdominal wall hernia requires debridement?

Debridement of Abdominal Wall Hernias

When debridement is required over an abdominal wall hernia, remove all necrotic and non-viable tissue including devitalized skin, subcutaneous fat, necrotic fascia, and any gangrenous bowel, while preserving viable muscular layers and their neurovascular supply to enable subsequent reconstruction.

Tissue Layers Requiring Debridement

The extent of debridement depends on the degree of contamination and tissue viability:

Skin and Subcutaneous Tissue

• Remove all necrotic skin and devitalized subcutaneous fat down to viable, bleeding tissue 1
• Debride any infected or non-viable skin overlying the hernia defect, particularly in cases with skin grafts or prolonged open abdomen 2, 3
• In contaminated fields with enteric spillage, aggressive debridement of all contaminated soft tissue is mandatory 4

Fascial Layer

• Debride necrotic or infected fascia back to healthy, viable fascial edges that can support repair 1, 3
• Remove any previously placed infected synthetic mesh completely, as it cannot be salvaged in contaminated fields 4, 5
• Preserve fascial integrity where possible to enable primary closure or component separation 4

Muscular Layers

• Preserve viable muscle with intact neurovascular supply—the component separation technique relies on maintaining muscle innervation and blood supply 4
• Only debride frankly necrotic muscle tissue; avoid unnecessary muscle sacrifice that would compromise future reconstruction 3

Bowel and Viscera

• Resect any gangrenous or non-viable bowel identified during hernia repair with strangulation 4, 6
• In cases with entero-atmospheric fistula, debride surrounding granulation tissue and infected material while planning for delayed definitive fistula management 4

Critical Principles During Debridement

Preserve Reconstructive Options

• Maintain the neurovascular supply to the rectus abdominis and oblique muscles to enable component separation or transversus abdominis release for future reconstruction 4, 2
• Avoid direct application of negative pressure wound therapy on exposed bowel—cover viscera with plastic sheets or omentum first 4

Contamination-Based Approach

• CDC Class I (clean): Minimal debridement of hernia sac only 4, 7
• CDC Class II-III (clean-contaminated/contaminated): Debride all devitalized tissue and contaminated material; synthetic mesh can still be used if no gross spillage 7, 8
• CDC Class IV (dirty/peritonitis): Aggressive debridement of all infected and necrotic tissue; avoid synthetic mesh as fascial bridge 4, 8

Staged Approach for Complex Cases

• In critically ill patients with severe peritonitis or septic shock, perform damage control surgery with debridement and temporary abdominal closure 4, 6
• Skin-only closure is acceptable when definitive fascial closure cannot be achieved after debridement, with delayed reconstruction planned 4, 7
• Progressive closure can be attempted at each surgical revision, with incremental debridement as needed 4

Common Pitfalls to Avoid

• Never leave necrotic bowel in situ—delayed diagnosis beyond 24 hours significantly increases mortality 6
• Never place synthetic mesh directly over debrided bowel or in contaminated fields as a fascial bridge—this causes adhesions, erosions, and fistula formation 4, 8
• Never sacrifice viable muscle unnecessarily—this eliminates options for component separation and compromises functional outcomes 4, 3
• Never attempt primary fascial closure under tension after extensive debridement—this risks abdominal compartment syndrome and recurrent intra-abdominal hypertension 4, 6

Reconstruction After Debridement

Following adequate debridement:

• Primary fascial closure is ideal when achievable without tension 4, 8
• Non-cross-linked biologic mesh in sublay position is preferred when linea alba can be reconstructed after debridement 4, 8
• Cross-linked biologic mesh as fascial bridge may be used when fascial closure is impossible after extensive debridement 4, 8
• Component separation technique should be reserved for definitive closure, not temporary closure, after complete debridement and patient stabilization 4, 8