Can epigastric flap be sensitive and survive on the neural pedicle ?

Abstract

Introduction: Nowadays in reconstructive plastic surgery it is very popular to use island flaps for covering soft tissue defects. I.Kuran et al (2000) reported high level of satisfaction after surgery in the group of patients who received a treatment by using sensitive flaps. In this way transposition of flap that includes in pedicle sensitive nerve is very actually. It is well known that all nerves have their own vasculature (vasa nervorum) to supply nerve fascicles. In 1992 A.Masquelet reported about sural flap for covering defects of lower extremity. In pedicle of this flap situated sural nerve. Authors improved that vascular axis of this nerve can supply skin. In 2004 surgeons from Turkey presented a new model of flap - neural-island flap. This flap has no axial blood flow and based on sensitive nerve of rat (n.cutaneus femoris lateralis). For experimental surgeons is very necessary to have simple and reliable model of this flap. In this investigation we offer to use well known epigastric flap because its pedicle has sensitive nerve. Material and Methods: All Wistar rats (N=43) were divided into 2 series of experiment: anatomical study and surgical study. In anatomical study (n=5) under general anesthesia was made microdissection of epigastric nerve by using operating microscope. In surgical study all animals were divided into 4 groups. In group A (n = ll) was raised conventionally 2x2 cm epigastric flap in addition with ligation of superficial epigastric artery and vein, but epigastric nerve leaves intact. In group B (n = ll) was made epigastric skin graft - after raising of standard epigastric flap neurovascular pedicle was legated and cut. In group C (n=l 1) epigastric flap 2x2 cm was raised in new area in considering with anatomical study of epigastric nerve. Artery and vein was legated, but nerve was intact. In group D (n=5) was raised 1,5x1,5 cm epigastric flap in new area. Data analysis was made by using nonparametric statistics and Spearmen correlation. Results: Anatomical study shows that epigastric nerve has another area of innervation comparing with epigastric angiosome. This nerve goes with epigastric vessels in the first time. Than nerve that is deflected lateral and goes to the internal surface of femur and lateral surface of the back. In experimental study in the group A survival rate of flaps was 18,2%, in group B - 0%, in group C - 27,3%, in group D - 60%. There are no significant difference in survival between group A and B, and between group C and D (p>0.05). Correlation between group C and D is not significant.Conclusion: This investigation shows that epigastric nerve has different topography than superficial epigastric vessels. It is important for raising neural-island flap, because conventional epigastric flap of the rat (Finseth F., 1976) has not sensitive innervation. Epigastric nerve supplies epigastric skin flap in area of innervation but it is not significant for flaps with size 2x2 cm. There are positive statistical trend between survival rate and flap size. So, we propose new model of neural-island flap - sensitive epigastric flap. It is a good model for investigation survival rate of sensitive flap and role of epigastric nerve in blood supply of the skin.