The experiments on 10 rabbits have shown that morphological and ultrastructural changes in musculus rectus of the abdomen depended on the type of approach chosen for gall duct surgery. The most pronounced changes were observed in the muscle following transversal oblique incision according to S. P. Fedorov--T. Kocher approach and pararectal Louson--Tatit incision. With medial approarch the changes were much less marked. The animals operated on by supermedial incision served as control. The findings obtained show the advantages of medial approach over the traditional ones.