The Anatomic Feasibility of a Functional Chimeric Flap in Complex Abdominal Wall Reconstruction

BACKGROUND

Dynamic and functional abdominal wall reconstruction (FAWR) remains a complex challenge. The ideal flap should have a minimal donor-site morbidity and cover a large surface area with motor and sensory capabilities. The goal was to investigate the feasibility of using a free chimeric flap with anterolateral thigh (ALT) and rectus femoris (RF) components pedicled only on the motor nerve branch.

METHODS

Ten fresh cadavers were dissected with a designed chimeric thigh flap including ALT and RF flaps. Anterolateral thigh was designed and raised with the lateral femoral cutaneous nerve integrated, and the descending branch of the lateral circumflex femoral artery was preserved. Rectus femoris was elevated and the common pedicle was dissected up to the femoral origin. Accompanying motor nerve branches were carefully dissected to their femoral origin.

RESULTS

Twenty RF flaps were dissected and 9 were harvested as a true chimeric flap with ALT. The mean number of neurovascular bundles associated with RF flap was 2.11 ± 0.47, and the mean primary motor nerve average length was 9.40 ± 2.42 cm. The common vascular bundle in all 9 chimeric flaps was ligated, and the flap was rotated toward the abdomen pedicled only by primary motor nerve of the RF muscle. Nerve length was adequate for reach up to xiphoid area in all 20 flaps.

CONCLUSIONS

This study demonstrates the feasibility of the chimeric ALT/RF muscle free flap pedicled only by the motor nerve branch, with adequate flap rotation. Even with the limitations in a live patient, this flap would be an excellent option for FAWR in the right patient.

Abdominal wall allotransplantation

Allotransplantation of vascularized composite tissue is a new field of transplantation surgery. One application of this technique is abdominal wall transplantation used as a supplementary procedure to the transplantation of visceral organs in patients with abdominal compartment deficits. As abdominal wall closure problems are experienced in around 30-40% of such patients, peer reviewed conclusions on the viability of various options, are important for an informed choice of possible procedures. This review focuses on the abdominal wall allotransplantion procedure. Our search provided 35 appropriate references which we used to support our findings as follows: abdominal wall transplantation was performed in 33 patients at seven centres. Of these, 30 had a full thickness abdominal wall transplanted from the same donor, 3 from a second donor. Three had visceral organ transplants and in addition, the posterior sheet of the rectus muscle fascia. In summary, our findings were that abdominal wall allotransplantation does not jeopardize the outcome of visceral organs transplantation. There is no higher risk of complications or rejection of the visceral organs. There have been no fatalities as a direct result of complications due to abdominal wall transplantation. Finally, the transplanted abdominal wall may provide an early warning of rejection before diagnostic tests on the bowel are symptomatic.