Methods: Human saphenous vein graft was obtained from ten patients and then divided into four equal parts. Saphenous vein grafts were distended in the heparinized lactated ringer's solution at pressure not exceeding 20 mmHg in Group 1 (Control group), and distended 80 mmHg in Group 2 (Lactated Ringer's group). Saphenous vein grafts were distended in the heparinized lactated Ringer's solution containing papaverine at pressure not exceeding 80 mmHg in Group 3 (Papaverine group), and distended at same pressure in the heparinized lactated Ringer's solution containing sodium nitroprusside in Group 4 (Sodium Nitroprusside group). Vein segments were storaged in these solutions at room temperature for one hour. All saphenous vein segments were examined under light microscope for loss of the endothelium and damage to the media and scored from 0 to 3.

Results: The mean scores were 0.7 ± 0.82 in Group 1, 1.3 ± 0.67 in Group 2, 2.0 ± 0.66 in Group 3 and, 1.1 ± 0.87 in Group 4. Score in sodium nitroprusside group was found to be significantly better than the others.

Conclusions: Our results show that supplementation of sodium nitroprusside to the preservation solution preserves the endothelium.