Aim: NG solution composed of nicardipine and nitroglycerin is a new anti-spastic solution for arterial grafts. We investigated its efficacy on the left internal thoracic artery (LITA) during off-pump coronary artery bypass grafting (OPCAB).
Methods: The free flow of LITA in 41 OPCAB patients was measured. The patients were divided to four groups: LITA pedicle wrapped with normal saline (Group I, N.=10) or NG (Group II, N.=11); or in addition to wrapping, 2 cc NG (Group III, N.=10) or normal saline (Group IV, N.=10) injected into LITA. After 30 min, the distal end free flow and the graft flow by an ultrasound probe were measured.
Results: The free flow significantly increased in Group II (30.0±4.7 vs. 21.6±4.5 cc/min, P=0.007) and III (70.0±11.5 vs. 24.5±6 cc/min, P=0.001) but not in Group I (20.8±4.7 vs. 19.4±4.1 cc/min, P=0.33) or IV (35.8±7.5 vs. 29±9.2 cc/min, P=0.06) with significant differences between the Group III to all other groups (P=0.016-0.001). The graft flow by ultrasound probe was significantly higher in Group III (41.2±6.2 cc/min) than that in Group IV (24.1±3.1 cc/min, P=0.028).
Conclusion: Use of NG solution for LITA graft preparation is a choice of antispastic protocol. NG solution used either topically or intraluminally significantly increases the blood flow of IMA grafts with the best effect obtained by intraluminal injection. The present study provides an additional anti-spastic method by using second generation of calcium antagonists and nitric oxide donor in coronary artery bypass surgery.