Arterial Supply of Sciatic Nerve and Its Impact on Clinical Practice

Abstract

Sciatic nerve is the nerve of the posterior compartment of thigh; it is formed in the pelvis from the ventral rami of L4 to S3 spinal nerves. It leaves the pelvis via the greater sciatic foramen below piriformis and divides into common peroneal nerve and tibial nerve at the level of the upper angle of the popliteal fossa. The vasculature of peripheral nerves is adapted specifically to their structure and function. Arterial vessels that reach main nerve trunks originate from the adjacent main arteries or their muscular or cutaneous branches. Although variability in arterial supply of sciatic nerve was discussed by some authors it is still deficient. To minimize sciatic nerve ischemia and its concomitant problems, an understanding of the origin and course of the arteries supplying it in the gluteal region and the posterior compartment of thigh is important. The present study aimed to detect the different arteries supplying the sciatic nerve in the gluteal and posterior thigh regions and to study the importance of this in clinical practice. Three cases subjected to vascular surgery and twenty lower limbs of ten formalin preserved male cadavers were used. Higher division of sciatic nerve was observed in all specimens. In 6 specimens (30%), arterial supply of sciatic nerve originated from the inferior gluteal artery, 6 specimens (30%)from first, second and third perforating arteries, 5 specimens (25%)from the lateral circumflex femoral artery and 3 specimens (15%)from internal pudendal artery. Anastomosis between internal iliac artery through its internal pudendal branch and external iliac artery through perforating arteries was observed. It was concluded that there is a good anastomosis between internal iliac and profunda femoris artery on the same side but cross pelvic anastomosis is absent or deficient and in case of profunda femoris occlusion we should preserve internal pudendal artery and the reverse.