Intraoperative and laboratory evaluation of skeletonized versus pedicled internal thoracic artery

The skeletonization of internal thoracic artery is postulated to improve graft length, early blood flow, sternal blood supply, and postoperative respiratory function. Concern exists that skeletonization may injure internal thoracic artery, precluding good results of surgery. Reports on endothelial function of skeletonized internal thoracic artery are lacking.

A prospective assessment of early clinical outcomes of 357 consecutive patients undergoing coronary artery bypass grafting was performed: 287 patients with nonskeletonized and 70 with skeletonized left internal thoracic artery (LITA). The lengths of LITA and of its discarded distal segment, as well as free LITA blood flow, were measured. The dose-effect relationship for relaxation to acetylcholine was studied in the organ bath.

Apart from a higher incidence of breaching the pleura with nonskeletonized LITA the clinical outcomes were comparable. The length of skeletonized LITA was 17.8+/-1.14 cm versus 20.3+/-0.52 cm skeletonized (p = 0.11). The length of discarded LITA was shorter in nonskeletonized artery (0.8+/-0.28 cm versus 2.6+/-0.49 cm; p = 0.022). The free LITA blood flow was 66.3+/-7.42 mL/min in nonskeletonized vessel versus 100.3+/-14.84 mL/min in skeletonized (p = 0.048). The acetylcholine-induced relaxation was similar in both groups (maximal relaxation, 80.7%+/-5.95% in nonskeletonized versus 72.9%+/-9.11% in skeletonized; not significant; negative logarithm of half-maximal effect, 7.43+/-0.18 versus 7.1+/-0.10, respectively; p = 0.063).

Skeletonization does not damage the endothelial function of the LITA. Higher free blood flow and available LITA length should encourage the use of skeletonized LITA in clinical practice.