What is the role of mesh in central hernia repair?

Mesh Use in Central Hernia Repair

Mesh should be used for central hernia defects larger than 3 cm that cannot be closed with direct suture, as it significantly reduces recurrence rates compared to primary repair alone. 1, 2

Indications for Mesh Use in Central Hernia Repair

• Mesh reinforcement is strongly recommended for defects larger than 3 cm, as primary repair alone has shown recurrence rates as high as 42% 1
• For small defects (<3 cm) without contamination, mesh repair is still preferred due to significantly lower recurrence rates compared to tissue repair 2, 3
• In clean surgical fields (CDC class I), synthetic mesh should be used for both ventral and groin hernias 2, 4
• In clean-contaminated fields (CDC class II), synthetic mesh can still be safely used even with intestinal strangulation and/or concomitant bowel resection without gross enteric spillage 2, 5

Mesh Selection Based on Surgical Field Classification

• For clean surgical fields (CDC class I), synthetic mesh is recommended due to lower recurrence rates 2, 3
• For clean-contaminated fields (CDC class II), synthetic mesh can still be used safely without increased 30-day wound-related morbidity 2, 5
• For contaminated or dirty fields (CDC classes III and IV):
  • Primary repair without mesh is recommended for small defects (<3 cm) 2, 6
  • Biological or biosynthetic meshes are suggested when direct suture is not feasible for larger defects 1, 2

Types of Mesh Materials

• Biosynthetic, biologic, or composite meshes are suggested due to their lower rate of hernia recurrence, higher resistance to infections, and lower risk of displacement 1, 7
• Biological meshes have shown lower rates of hernia recurrence and higher resistance to infections compared with synthetic meshes 1, 8
• Polytetrafluoroethylene (PTFE/Gore-Tex) is commonly recommended for diaphragmatic reconstruction due to its strength, impermeability, and reduced risk of bowel adhesions 1
• Reinforced biologic mesh (with permanent suture weave) may combine the advantages of incorporation with long-term strength 7

Surgical Approach and Technique

• Laparoscopic approach shows lower wound infection rates and shorter hospital stays compared to open procedures 5
• Mesh placement options include:
  • Intraperitoneal Onlay Mesh (IPOM) - mesh placed inside peritoneal cavity and fixed to abdominal wall 5
  • Transabdominal Preperitoneal (TAPP) Repair - laparoscopic technique placing mesh in preperitoneal space 5
  • Retrorectus placement - mesh placed behind rectus muscle but anterior to posterior rectus sheath 7

Clinical Pitfalls and Considerations

• Mesh should not be avoided in clean or clean-contaminated fields due to fear of infection, as evidence shows it's safe and reduces recurrence 2
• Synthetic mesh should be avoided in grossly contaminated fields (CDC class III/IV) as infection rates can be high (up to 21%) 2, 6
• Long-term follow-up shows that while mesh reduces recurrence, benefits may be partially offset by mesh-related complications (5.6% for open mesh repair and 3.7% for laparoscopic mesh repair at 5 years) 3
• Mesh-related complications can include seroma formation, which occurs more frequently with mesh repair than with non-mesh repair 4
• Central mesh recurrence through the mesh itself is a rare but reported complication, suggesting the need for adequate mesh strength 9

Antimicrobial Considerations

• Short-term prophylaxis is recommended for CDC class I (clean field) 2
• 48-hour antimicrobial prophylaxis is recommended for CDC classes II and III (clean-contaminated and contaminated) 2
• Full antimicrobial therapy is recommended for CDC class IV (dirty field) 2