Incisional Hernia

An incisional hernia is protrusion through a fascial defect at the site of a previous abdominal wall incision.

It results from failure of durable fascial healing rather than a natural anatomical weakness. Risk factors include surgical site infection, obesity, smoking, diabetes, emergency surgery and previous wound dehiscence.

Defects vary from small localised failures to loss of abdominal wall domain with major muscular retraction.

The clinical problem is not merely closing a hole. Durable repair should restore functional continuity of the abdominal wall while minimising recurrence and wound morbidity.

Patients usually report a swelling at or adjacent to a previous scar that enlarges with standing or straining.

Symptoms include pressure, dragging discomfort, pain, impaired mobility and cosmetic deformity.

Assess:

• Defect size and location
• Reducibility
• Number of defects
• Skin quality
• Previous mesh
• Rectus muscle position
• Loss of domain
• Stomas or fistulas

Acute irreducibility, focal severe pain, vomiting or bowel obstruction suggests incarceration.

Small uncomplicated defects may be diagnosed clinically.

CT abdomen and pelvis: preferred for large or complex incisional hernias; define fascial dimensions, rectus position, hernia contents, previous mesh and loss of domain.

Elective repair is indicated when symptoms, progressive enlargement or functional impairment justify the operative risk.

Optimise major modifiable risk factors before complex reconstruction, particularly smoking, obesity and poor glycaemic control.

Mesh repair should be used for most incisional hernias because suture repair alone has substantially higher recurrence. Randomised evidence shows recurrence around 12% after mesh repair compared with approximately 30% after suture repair.

Aim for primary fascial closure with mesh reinforcement rather than bridging the defect.

Retromuscular mesh placement is preferred when anatomy allows. It provides durable reinforcement while keeping permanent mesh away from the abdominal viscera.

Open, laparoscopic and robotic approaches are all valid. Selection depends on defect size, previous operations, need for adhesiolysis, abdominal wall anatomy and surgeon expertise.

Large defects with medialised rectus muscles that cannot be closed without tension may require myofascial advancement such as posterior component separation with transversus abdominis release.

Avoid component separation purely to place a mesh when uncomplicated fascial approximation can be achieved by a simpler repair.

Emergency surgery is required for strangulation, bowel ischaemia, perforation or obstruction that cannot be managed safely without operation.