Surgery Shelf Exam Sample Questions

The correct answer is D. Bilateral component separation with biologic mesh

Explanation: Incisional hernia rates after laparotomy occur in 10-20% of patients. Risk factors for hernia include emergency operation, obesity, smoking, decreased tissue healing due to underlying medications or medical conditions, healing under tension, technical error, and multiple prior procedures or prior hernia repairs. Primary suture repair in hernia defects > 3 cm have a high rate of recurrence, up to 30-40%. The problem with primary suture repair is suture line tension. Even with the addition of mesh to primary suture closure, hernia rates still approach 25%. In 1990, Ramirez described the component separation technique. As originally described, large subcutaneous flaps are created lateral to the defect, followed by bilateral incisions of the external oblique aponeurosis, and if necessary, incision of the posterior rectus sheath. Up to 10 cm of rectus fascia can be mobilized using this method, to allow for tension-free closure of midline tissue. Unfortunately, early reports were plagues with wound infections and relatively high recurrence rates of 15-20%. With improved technique, including preservation of the perforator vessels of the abdominal wall, and the addition of mesh, recurrence rates are now around 4-5%. In the above scenario, due to the large midline gap, a component separation is necessary. The addition of mesh is advised as well, for the optimal repair. However, given the small bowel contamination, permanent mesh is not the safest answer. Biologic mesh can be used even in heavily contaminated situations, as tissue ingrowth will occur as the mesh is slowly absorbed. (A) It is unlikely that the adhesions will soften any more, so a future attempt at repair may be even more difficult. Though a full thickness enterotomy requiring repair is not the ideal circumstance, it does not mean that the procedure should be completely aborted. (B) Polyglactin (Vicryl) mesh is absorbable within months and especially in the bridging position, and lends itself to unacceptably high recurrence rates. It should only be used as a purposeful temporary cover or bridge with the intention of permanent hernia fix in the future. (C) Mesh should be used as tissue reinforcement to decrease hernia recurrence rates. (E) Though the idea of not using permanent mesh in a contaminated environment has recently been challenged, it is safest to use a biologic mesh, with very low recurrence rates in combination with component separation without worry of subsequent mesh explantation.