Quantification of thermal spread and burst pressure after endoscopic vessel harvesting: a comparison of 2 commercially available devices.

OBJECTIVE: Endoscopic vein harvesting systems have grown in popularity and are becoming the gold standard for coronary artery bypass grafting. Although a consensus is present that endoscopic vessel harvesting minimizes wound complications, long-term graft patency remains a concern. It has been proposed that endoscopic vessel harvesting affects graft patency because of irreversible trauma to the endothelium. This study was performed to examine the extent of thermal injury caused by 2 commercially available endoscopic vessel harvesting systems in a porcine model.

METHODS: Superficial epigastric veins and saphenous arteries were exposed in 10 anesthetized swine. All vessel samples (conduits) were harvested randomly with either a VirtuoSaph (Terumo Cardiovascular, Ann Arbor, Mich) or VASOVIEW 6 (MAQUET, Inc, Wayne, NJ) endoscopic vessel harvesting system. Conduits were harvested and saved for either histologic analysis or burst-pressure test. Statistical differences were analyzed by using a Wilcoxon rank sum test in SAS 9.2 software (SAS Institute, Inc, Cary, NC) for thermal spread and a 2-tailed t test with equal variance for burst pressure.

RESULTS: The average thermal spreads for saphenous artery and superficial epigastric vein conduits were significantly shorter in the VirtuoSaph group (0.42 ± 0.08 and 0.49 ± 0.05 mm, respectively) than in the VASOVIEW 6 group (1.05 ± .04 and 0.94 ± 0.19 mm, respectively). No significant differences were observed in burst pressure.

CONCLUSIONS: The length of thermal spread is short in arterial and venous conduits (0.4-1.1 mm) and depends on the endoscopic vessel harvesting system. Clinical protocols should include a minimal length of the cauterized branch to ensure that thermal spread does not reach the main vessel. The results of this study suggest that at least 1 mm is sufficient.