ABSTRACT
To study the neurovascular anatomy of the rectus abdominis muscle with reference to their relation to tendinous intersections of the muscle. Eight human cadavers were injected with latex/lead oxide mixture into the superior epigastric artery and external iliac artery. The vascular architecture of the superior and deep inferior epigastric arteries was studied together with the nerve supply of rectus abdominis muscle. The superior epigastric supplied the upper part of rectus muscle. It pierced the rectus muscle between the first and second tendinous intersections. The inferior epigastric artery had 3 patterns of branching; Type I the artery ascended as a single stem parallel to the muscle fibers [in 37.5% of cases]; Type II the vessel divided into 2 branches of different size after giving a perimuscular branch to the lower portion of rectus [in 50% of cases]; The medial branch was short and small to supply the lower medial portion of rectus while the lateral branch was longer with larger diameter. It ran parallel to the muscle fibers to a level above the umbilicus. Type III the deep inferior epigastric artery divided into 3 branches [in 12.5% of cases], the lower one was the smallest. The other 2 branches were of the same caliber, the medial one was short never reach the umbilicus supplying the lower medial portion of the muscle, and the lateral one was longer, ran parallel to the muscle fibers to a level above the umbilicus. The rectus muscle was innervated by lower thoracic spinal nerves in a segmental manner. The muscular perforators arranged in a vertical row from the posterior rectus sheath to the deep surface of rectus. The point of their perforation to the muscle corresponded approximately to the vascular axis which situated at the junction of lateral 1/3 and medial 2/3 of rectus. The perforators of the anterior rectus sheath to skin arranged also in a vertical row lateral to mid line of rectus above the umbilicus and medial to mid line below the umbilicus. Both the superior and deep inferior epigastric arteries supplied the rectus abdominis. The inferior epigastric artery was more reliable than the superior epigastric artery, as it was easily accessible and easily separated from the muscle with minimal damage. It can be used for free tissue transplantation to perineum, genital area and the abdominal wall. A strip of anterior rectus sheath, should be preserved between the intersections to prevent rupture of the vulnerable rectus abdominis and its vessels due to presence of substantial connective tissue within the muscle between the tendinous intersections. During obtaining muscle flaps, denervation of the remaining muscle occurred if more than medial half of the muscle was taken with the flap, due to vertical arrangement of segmental nerve supply of the rectus at the junction of lateral 1/3 with the medial 2/3