Histological and immunohistochemical evaluation of human saphenous vein harvested by endoscopic and open conventional methods

OBJECTIVES: The introduction of endoscopic saphenous vein harvesting (ESVH) has been reported to decrease saphenectomy-associated wound pain and infection, compared with the traditional open conventional saphenous vein harvesting (OCSVH) technique. Despite all these benefits, the rate of adoption among surgeons has been variable. Criticism of this technique centres on the risk of injury at the time of vein harvest with its potential detrimental effect on structural viability and long-term patency. The aim of our study is to investigate the endothelial preservation of saphenous vein grafts harvested by various extraction methods. METHODS: A prospective, observational study of 30 human saphenous vein grafts was performed to evaluate endothelial preservation by haematoxylin-eosin and CD 31 staining methods. The saphenous vein was harvested endoscopically either by an open tunnel (OT-ESVH), closed tunnel (CT-ESVH) or an OCSVH harvesting technique. Research samples were collected without distension to avoid intraluminal dilatation and endothelial disruption. Both haematoxylin-eosin and immunohistochemistry slides were imaged by a high-resolution slidescanning system. RESULTS: Haematoxylin-eosin staining of the CT-ESVH group showed mostly preserved endothelium (P = 0.398) with some endothelial stretching (P = 1.0) and no endothelial detachment (P = 0.197). The OT-ESVH group showed marked endothelial stretching (P = 0.053). However, the OCSVH group showed significantly more endothelial detachment than the endoscopic groups (P = 0.01). The mean grading score of immunohistochemistry using the CD 31 antibody was much lower in the OT-ESVH group (1.6 +/- 0.84, P = 0.009), showing more poorly preserved endothelial cells than the CT-ESVH and OCSVH groups. CONCLUSIONS: We observed more endothelial stretching in the OT-ESVH group, which in our opinion, was due to lack of subcutaneous tissue separation, poor visualization and traction stresses across the wall of the saphenous vein. However, the OCSVH method revealed poor endothelial protection with areas of endothelial detachment, not observed with both endoscopic techniques. Interestingly, most preserved endothelium was found in the CT-ESVH group, which was previously known to be associated with worse graft patency.