The Superficial Inferior Epigastric Artery Fascia Flap in Rats

Abstract

Background An adipofascial flap in the rat may provide new options for adding vascularization to scarred or nonvascularized beds for a variety of research studies. Current literature lacks sufficient description for a simple reproducible flap model for a vascularized pedicled flap in rats, in particular for neovascularization of allograft nerves for the reconstruction of sciatic nerve defects. The purpose of this study was to describe a surgical technique and determine long-term survivability for the pedicled superficial inferior epigastric artery fascial (SIEF) flap in the rat to meet requirement for a tunneled adipofascial flap to add vascularization to the sciatic nerve area. Methods The technique and use of a 4 × 3-cm SIEF flap are described. Twenty Lewis rats underwent the technique to determine feasibility. The flap was wrapped around processed allograft nerve reconstructions and viability of the flap was evaluated after 12 and 16 weeks. To visualize vessels, nerve grafts were harvested at 12 weeks and stained with hematoxylin-eosin and an antibody against microvessels (CD-34). Results All flaps remained viable after survival of 12 and 16 weeks. Complications included one hematoma formation and two lymphocele formations that did not have any impact on the flap. Immunohistochemistry confirmed an increase in microvessels and Schwann cell nuclei in the SIEF group compared with nerve samples from the unoperated, contralateral side. Conclusion A pedicled adipofascial flap model in the rat to provide a vascular bed for sciatic nerve reconstruction is detailed with long-term survivability evaluation of the flap. This flap is technically simple to be harvested and is suitable for revascularization procedures of various tissues in the lower abdomen, genital area, thigh, or upper limb of the rat.

Surgical Angiogenesis of Decellularized Nerve Allografts Improves Early Functional Recovery in a Rat Sciatic Nerve Defect Model

“…In group 3, the optimized processed allograft was wrapped with a superficial inferior epigastric artery fascial flap. 19 All groups had survival periods of 12 and 16 weeks ( n = 10 per time point per group) for evaluation of outcomes. Time points were chosen based on previous research and the neuroregenerative capacity of rats.…”

“…In group 3, this optimized processed allograft was wrapped with a pedicled superficial inferior epigastric artery fascial flap as previously described. 19 In short, the femoral artery was identified in the groin and the superficial inferior epigastric vessels were exposed. The superficial inferior epigastric artery fascial flap was tunneled subcutaneously toward the nerve reconstruction and wrapped around the nerve to surround both nerve anastomoses.…”

Microcomputed analysis of nerve angioarchitecture after combined stem cell delivery and surgical angiogenesis to nerve allograft

“…In group II, a 10-mm allograft was used to reconstruct the nerve gap. In group III-V, these nerve allografts were placed in a vascularized bed using a pedicled superficial inferior epigastric artery fascia (SIEF) flap to provide surgical angiogenesis 6 . Prior to surgery of group IV and V, allografts were dynamically seeded with undifferentiated MSCs and MSCs differentiated into Schwann cell-like cells, respectively, combining stem cells and surgical angiogenesis.…”

“…In group III-V, surgical angiogenesis was provided to the allograft (group III), combined with undifferentiated MSCs (group IV) and differentiated MSCs (group V), respectively. In detail, the nerve gap was repaired with an allograft which was consecutively wrapped in the pedicled SIEF flap 6 . Briefly, the femoral artery was identified in the groin on the ipsilateral side of the nerve reconstruction, whereafter the superficial inferior epigastric (SIE) vessels were exposed.…”

“…Diminishing fibrosis and central necrosis in nerve grafts by early revascularization of the graft may enhance axonal regeneration, especially in larger diameter nerve grafts 4 . Surgical angiogenesis by a pedicled adipofascial flap is a potential strategy to improve the microcirculation and thus revascularization [6][7][8] .…”