Is Skeletonized Internal Mammary Artery Harvesting better than Pedicled Harvesting in Respect of the Sternal Blood Flow?: An Estimation Using Bone Scan

Baek, Wan Ki; Son, Kuk Hui; Kim, Young Sam; Kim, Joung Taek; Yoon, Yong Han; Kim, Kwang Ho; Choe, Wonsick

Abstract

BACKGROUND: One of the theoretical advantages of skeletonized internal mammary artery harvesting in coronary artery bypass surgery is to minimize the interruption of the sternal blood flow inevitably accompanied by internal mammary harvesting. A study using bone scan is designed to determine the effects of internal mammary artery harvesting technique on the sternal blood flow. MATERIAL AND METHOD: From April 2002 to March 2003, 27 patients out of 48 patients who underwent the isolated coronary bypass surgery were enrolled into the study. The enrolled patients underwent bone scan in the preoperative period and postoperative period respectively. Bilateral internal mammary arteries were used in 8 patients (BIMA group) and single left internal mammary artery in 19 patients (LIMA group). The patients in LIMA group were divided into two groups: LIMA_skel group, in whom left internal mammary artery was harvested in skeletonized fashion (n=12), and LIMA_ped group, in whom left internal mammary artery was harvested in pedicled fashion (n=7). After the bone scan, the region of interest (ROI) was created on the left half of the sternum and the mirror image with the same pixel numbers was placed on the right half of the sternum. The mean counts per pixel on the left side of the sternum was compared with those on the right side and expressed as left to right ratio (L/R ratio). RESULT: In LIMA group, the L/R ratio decreased from 94.6+/-4.1% to 87.9+/-6.9% (p=0.003) after the operation as compared to BIMA group, in which no change of the L/R ratio was observed. The changes of the L/R ratio in LIMA_skel group and LIMA_ped group were from 95.3+/-4.2% to 88.3+/-7.7% and from 93.4+/-3.9% to 87.4+/-5.8% respectively. The % changes in L/R ratio were -7.44+/-7.08 in LIMA_skel group and -6.17+/-9.08 in LIMA_ped group, which did not reach the statistical difference.
CONCLUSION
Ipsilateral sternal blood flow is interrupted by internal mammary artery harvesting as evidenced by the decrease in L/R ratio after left internal mammary artery harvesting irrespective of the harvesting techniques. Skeletonized harvesting did not show superiority in respect to sternal blood flow as compared to pedicled harvesting.