Appropriate Mesh Overlap in Hernia Repair
For optimal outcomes in hernia repair, mesh should overlap the defect by at least 5 cm for laparoscopic repairs and for open repairs of defects >4 cm, while smaller defects require 2-3 cm overlap depending on size. This recommendation is based on evidence-based guidelines from major hernia societies that prioritize prevention of recurrence and associated morbidity 1.
Recommended Mesh Overlap Based on Repair Type and Defect Size
Laparoscopic Ventral/Incisional Hernia Repair
- All defect sizes: ≥5 cm overlap in all directions 1, 2
- Insufficient overlap is strongly associated with hernia recurrence 2
- Studies show recurrence rates decrease significantly with increasing overlap: 8.6% with <3 cm overlap, 4.6% with 3-5 cm overlap, and only 1.4% with >5 cm overlap 2
Open Ventral/Incisional Hernia Repair
- Defects <1 cm: ≥2 cm overlap 1, 3
- Defects 1-4 cm: ≥3 cm overlap 1, 3
- Defects >4 cm: ≥5 cm overlap 1, 3, 4
- For retromuscular sublay repairs, at least 5-6 cm overlap is recommended in all directions 4
Diaphragmatic Hernia Repair
- Mesh should overlap the defect edge by 1.5-2.5 cm 5
- For defects larger than 8 cm or an area >20 cm², interposition of a graft with adequate overlap is recommended 5
Factors Affecting Mesh Overlap Requirements
Defect Size
- Larger defects require greater overlap to distribute tension and prevent recurrence 1, 4
- Primary repair without mesh is only recommended for small defects (<3 cm) in contaminated fields 5
Surgical Approach
- Laparoscopic repairs require greater overlap (≥5 cm) than open repairs for equivalent defect sizes 1, 2
- In laparoscopic repairs, mesh tends to shift away from the operative side, potentially leading to recurrence if overlap is inadequate 6
Mesh Placement Technique
- Retromuscular sublay position is preferred for open repairs, requiring 5-6 cm overlap 4
- For laparoscopic IPOM (intraperitoneal onlay mesh), secure with transfascial sutures at cardinal points before tacking 1
- Factors associated with sufficient overlap include myofascial release, minimally invasive approach, and onlay mesh location 3
Clinical Considerations and Pitfalls
Common Pitfalls
- Insufficient overlap: Only 25.7% of ventral hernia repairs in a state-wide cohort had sufficient overlap according to guidelines 3
- Mesh shift: Can occur over time, especially away from the operative side in laparoscopic repairs 6
- Inadequate fixation: Mesh should be secured with transfascial sutures at cardinal points before tacking 1
Special Considerations
- In contaminated fields (CDC wound class III/IV), biological mesh may be used when direct suture is not feasible 5
- The choice between cross-linked and non-cross-linked biological mesh should depend on defect size and contamination degree 5
- For unstable patients with severe sepsis/septic shock, open management may be preferred 5, 1
Conclusion
Adequate mesh overlap is critical for preventing hernia recurrence. Despite clear guidelines recommending specific overlap measurements based on defect size and repair technique, many repairs fail to achieve sufficient overlap in clinical practice. Surgeons should ensure proper mesh sizing with appropriate overlap in all directions to minimize recurrence risk and optimize patient outcomes.