Incisional Hernia
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Direct answer
An incisional hernia is a bulge through a healed surgical scar, occurring after roughly 10–15 per cent of laparotomies (commonly quoted ranges vary), with wound infection the single most important modifiable risk factor alongside obesity, smoking, malnutrition, steroids and faulty closure technique. Because suture-only repair carries recurrence of a quarter to a half, mesh repair is standard whenever feasible, placed in the retromuscular sublay (Rives-Stoppa) plane as the preferred open technique, intraperitoneally (IPOM) in laparoscopic repair, with component separation reserved for giant defects with loss of domain. Preoperative optimisation — weight reduction, smoking cessation, glycaemic control and treating lung disease with cough — is as decisive as the operation itself.
What you must remember
- Risk factors: surgical site infection (strongest), obesity, chronic cough and smoking, constipation and straining, malnutrition, steroids, diabetes, emergency and midline incisions.
- Closure technique matters: mass closure with a suture length to wound length ratio of at least 4 to 1, using small bites and slowly absorbable monofilament, lowers hernia rates.
- Repair options by mesh plane: onlay (above fascia), inlay (bridging the defect, higher recurrence), sublay or retromuscular (Rives-Stoppa, generally preferred open plane), and underlay intraperitoneal mesh (IPOM laparoscopic).
- Component separation (releasing the external or anterior rectus sheath layers) expands the abdominal wall to close giant defects with or without mesh.
- Loss of domain, where herniated viscera cannot be returned to the abdomen, may need botulinum toxin injection of the lateral muscles or progressive pneumoperitoneum before repair.
- Complications of the hernia itself: incarceration, strangulation, skin ulceration over a tight neck, and impaired respiration in giant hernias.
- Postoperative rules: avoidance of heavy lifting for about 6–12 weeks, weight reduction and treatment of cough or constipation to protect the repair.
Common confusion
Students often confuse incisional hernia with wound dehiscence. Dehiscence is early fascial failure in the postoperative weeks, an open burst abdomen needing re-suturing, whereas an incisional hernia is a late, healed-scar defect presenting months to years later with a reducible bulge and a cough impulse. The second confusion is cosmetic bulge versus true hernia: a divarication of the recti or a lax scar without a fascial defect needs no mesh.
Exam-focused takeaway
Expect one-liners on the strongest risk factor (wound infection), the recurrence of suture-only repair, and the preferred mesh plane (retromuscular sublay). Stems may describe a midline scar with a reducible swelling and cough impulse years after laparotomy, or ask which technique suits a giant hernia (component separation). Laparoscopic IPOM questions test the need for anti-adhesive-coated mesh facing bowel and closure of all port sites over 10 mm.
Frequently asked questions
Which factor most strongly predisposes to incisional hernia?
Postoperative surgical site infection of the wound is the most consistently identified modifiable risk factor, together with obesity and technically poor closure.
What is the Rives-Stoppa repair?
A retromuscular sublay repair in which a large mesh is placed behind the rectus muscles in the avascular plane above the peritoneum, giving wide mesh-fascia overlap behind strong tissue.
When is component separation used?
For large or giant defects with loss of domain where the recti cannot be approximated; releasing incisions in the oblique aponeuroses lengthen the wall to allow fascial closure.
Why is inlay mesh repair discouraged?
Bridging mesh that merely fills the defect is not fixed under physiological tension between healthy fascial edges and is associated with higher recurrence and bulging.
Can an incisional hernia be repaired laparoscopically?
Yes, by intraperitoneal onlay mesh (IPOM) with barrier-coated mesh, best suited to moderate defects in patients without extensive dense adhesions or loss of domain.