Anatomical rationale for use of the latissimus dorsi flap during the cardiomyoplasty operation.

Abstract

The cardiomyoplasty procedure involves the use of a transformed skeletal muscle to augment cardiac pump function or to substitute for the heart after parietal resection. This study of the intramuscular vascularization of latissimus dorsi was carried out in order to establish the relationship between the dominant thoracodorsal blood supply and the distal supply issued from the intercostal and lumbar arteries. This data is mandatory for the safe manipulation of the muscle flap during cardiomyoplasty. Thirty human latissimus dorsi flaps were carefully studied. We confirmed anatomically as well as angiographically previous macroscopic anatomical reports, as well as the constancy of the neurovascular pedicle. Three principal branching patterns were observed for the thoracodorsal artery. The thoracodorsal artery divides into three main tributaries in 20/30 (67%), and into two tributaries in 10/30 (33%) of the flaps observed. When three tributaries were observed, one of them was a small recurrent artery for the proximal third of the latissimus dorsi (14/20, 70%). Thus the distal vascularization is actually dependent on three principals in 6/30 (20%) and two principals in 24/30 (80%). From these two or three principals emerge several subsequent longitudinal branches (5 to 9) that have a straight course until their distal anastomoses with segmental arterial pedicles issued from intercostal and lumbar arteries. The latter ligation can thus occur without ischemic damage to the medial and distal aspect of the flap. This study emphasizes that, due to macroscopic anatomic features and systematic intramuscular vascular distribution, the latissimus dorsi is probably the most suitable muscle for the purpose of cardiomyoplasty.