Sublay and Onlay Mesh Repair for Incisional Hernia

Sublay and onlay are open hernioplasty techniques that use a synthetic mesh to reinforce the abdominal wall in incisional hernia repair. They differ in mesh position relative to the fascial layers.

In the sublay technique (Rives-Stoppa), the mesh is placed in the retromuscular space behind the rectus muscle and over the posterior rectus sheath. This position uses intra-abdominal pressure to fix the mesh against the muscle, achieving low recurrence rates and reduced infection risk. In the onlay technique, the mesh is placed superficial to the anterior rectus fascia after primary fascial closure.

Sublay is generally preferred for medium and large defects in stable patients, while onlay remains a useful, technically simpler option in selected cases such as obese patients, contaminated fields or extensive subcutaneous dissection. Both require meticulous surgical technique, infection control, optimization of comorbidities and structured postoperative recovery.