Tunnelling versus open harvest technique in obtaining venous conduits for coronary bypass surgery

The tunnelling as opposed to the open harvest technique for harvesting long saphenous vein for coronary artery bypass procedures is a less frequently used technique as it requires more handling of the vein and this may induce trauma. This study aims to compare the degree of endothelial denudation and donor site morbidity between the two different harvest techniques.

Saphenous vein segments in 78 patients (45 in tunnelling versus 33 in open harvest group) undergoing coronary artery bypass procedures were examined by light microscopy and graded according to the extent of endothelial denudation varying from grade 1 (most preserved) to grade 6 (>90% endothelial denudation). Clinical parameters relating to donor site morbidity including leg wound pain and infection were also assessed.

There was no statistical difference in the age, sex, macroscopic vein quality, length and time taken to harvest the veins between the two groups. The tunnelling technique always used thigh saphenous vein whereas nearly a third of veins harvested by the open harvest technique were lower leg veins (P=0.001). The tunnelling technique resulted in an endothelial score of 2.5 compared with 3.3 for the open harvest technique (P < 0.001). In addition, saphenous vein tunnelling resulted in significantly less leg wound pain (1.2 vs. 1.8, P=0.001), no leg wound infection (compared with 12.2% in open harvest group, P=0.02) and produced cosmetically more acceptable scars. Furthermore, length of hospital stay was significantly prolonged to 19.3 days in those with leg wound infection compared to 8.7 days in those without leg wound infection (P < 0.001).

These results show that saphenous vein tunnelling is an attractive alternative to the open harvest technique in obtaining venous conduits for coronary artery bypass procedures.