What are the surgical steps for Intraperitoneal (IPOM) onlay mesh repair?

Surgical Steps in Intraperitoneal Onlay Mesh (IPOM) Repair

The intraperitoneal onlay mesh (IPOM) technique involves placing synthetic mesh directly against the peritoneum to repair ventral and incisional hernias, with careful attention to proper mesh selection, fixation, and peritoneal closure to minimize complications.

Patient Preparation and Positioning

• Position patient supine with arms extended
• Prepare and drape the abdomen widely
• Administer appropriate prophylactic antibiotics based on wound classification:
  • Clean surgical field (CDC class I): Short-term prophylaxis 1
  • Clean-contaminated (CDC class II): 48-hour antimicrobial prophylaxis 1
  • Contaminated/dirty (CDC classes III/IV): Full antimicrobial therapy 1

Port Placement

• Create pneumoperitoneum using Veress needle or open Hasson technique
• Place initial camera port (10-12mm) away from the hernia defect
• Position additional working ports (5mm) laterally under direct vision
• Triangulate ports to allow optimal visualization and access to the hernia

Hernia Assessment

• Perform diagnostic laparoscopy to:
  • Identify hernia defect(s)
  • Assess for bowel viability if incarceration present
  • Evaluate for additional occult defects
  • Measure defect size accurately for appropriate mesh selection

Adhesiolysis and Hernia Content Reduction

• Carefully divide adhesions using sharp dissection
• Reduce hernia contents back into peritoneal cavity
• Assess bowel viability after reduction
• If strangulation is present, evaluate need for bowel resection
  • For intestinal strangulation without gross enteric spillage (CDC class II), prosthetic repair with synthetic mesh can still be performed 1
  • For bowel necrosis/gross enteric spillage (CDC class III/IV), primary repair is recommended for small defects (<3cm); biological mesh may be used for larger defects 1

Mesh Selection and Preparation

• Choose appropriate mesh based on:
  • Defect size (ensure minimum 3-5cm overlap beyond defect margins)
  • Contamination level (synthetic vs. biological)
  • Patient factors (obesity, immunosuppression)
• For clean surgical fields, synthetic mesh is recommended 1
• For contaminated fields, biological mesh may be preferred 1
• Prepare mesh by:
  • Marking orientation (if applicable)
  • Placing corner sutures for positioning

Mesh Placement and Fixation

1. Insert mesh through 10-12mm port
2. Unfold mesh intraperitoneally
3. Position mesh to ensure adequate overlap (minimum 3-5cm beyond defect margins)
4. Secure mesh using combination of:
   • Transfascial sutures at cardinal points
   • Tacks or staples around periphery (typically 1-2cm apart)
   • Consider fibrin glue for additional fixation to minimize pain 2

Closure

• Check for hemostasis
• Remove ports under direct visualization
• Close fascial defects at port sites ≥10mm
• Close skin incisions

Postoperative Care

• Early mobilization to prevent complications
• Monitor for common complications:
  • Seroma (0.4%)
  • Hematoma (1.6-1.86%)
  • Wound infection (0.4-1.6%) 3
• Pain management with multimodal analgesia

Special Considerations

Mesh-Related Complications

• Mesh infections may require individualized management:
  • Conservative treatment with antibiotics may salvage mesh in some cases
  • If conservative treatment fails, complete mesh removal may be necessary 1
  • After infected mesh removal, options include:
    • No new mesh implantation
    • Re-implantation of new synthetic light-weight, macroporous mesh
    • Replacement with biological mesh 1

Technical Variations

• Consider preperitoneal onlay mesh (PPOM) technique as an alternative to IPOM:
  • Creates peritoneal flap
  • Places mesh in preperitoneal plane
  • Closes peritoneum over mesh
  • May reduce mesh-related complications like adhesions, fistulas, and erosion 4, 5
• Ultra-fine polyethylene meshes show improved biocompatibility and reduced intraperitoneal adhesions compared to standard polypropylene meshes 6

Advantages of IPOM

• Shorter operative time (median 120 min vs. 180 min for open repair)
• Reduced hospital stay (6 vs. 8 days)
• Fewer complications (10% vs. 23%)
• Lower surgical site infection rates (1% vs. 21%) 7

Pitfalls and Caveats

• Ensure adequate mesh overlap (minimum 3-5cm) to prevent recurrence
• Avoid excessive tension during mesh fixation
• Be cautious with tack placement near neurovascular bundles to prevent chronic pain
• Consider patient-specific factors (obesity, immunosuppression) when selecting mesh
• For unstable patients with severe sepsis/septic shock, open management is recommended 1
• Recognize that mesh placement in contaminated fields carries higher risk of complications