New approach to patency and flow assessment after left internal thoracic artery hypoperfusion syndrome with additional saphenous vein graft to the left anterior descending artery with phase-contrast magnetic resonance angiography

Fasudil is a superior vasodilator for the internal thoracic artery in coronary surgery

BACKGROUND

The internal thoracic artery (ITA) is a very useful conduit for coronary artery bypass artery (CABG), with excellent long-term patency. With the purpose to dilate the ITA graft and increase graft free flow (GFF) intraoperatively, we evaluated the usefulness of intraluminal injection of fasudil, a Rho-kinase inhibitor, in comparison to the conventional graft dilating agent, papaverine.

METHODS

Between June 2011 and January 2012, 30 patients with ischemic heart disease who underwent isolated CABG using ITA were enrolled. The patients were randomly assigned to 2 groups: the fasudil group (n = 15) in which fasudil solution 0.9 mg/dL was injected into the ITA, and the papaverine group (n = 15) in which papaverine solution (0.4 mg/mL) mixed with heparinized blood was used. Outcome measures were left ITA GFF, heart rate, and mean blood pressure during flow measurements, and histopathologic examination of the ITA.

RESULTS

In the fasudil group, GFF increased significantly (p < 0.01) from 19.7 ± 15.2 mL/minute at baseline to 66.9 ± 31.7 mL/minute after fasudil injection. In the papaverine group, GFF increased significantly (p < 0.01) from 22.9 ± 17.3 mL/minute at baseline to 44.8 ± 26.7 mL/minute after papaverine injection. Blood pressure and heart rate did not change significantly after drug injection in both groups. The GFF was significantly higher (p = 0.038) in fasudil-treated ITA than in papaverine-treated ITA. Histopathologically, the diameter of the ITA was markedly increased after fasudil injection. Elastica van Gieson staining showed that the multiple elastic lamellae structure was intact.

CONCLUSIONS

Fasudil exhibited very potent vasodilatory effect on the ITA compared with conventional papaverine resulting in increased GFF. This agent is a useful graft dilating agent.

Double supply to left anterior descending artery by additional saphenous vein graft in internal thoracic artery malperfusion syndrome

OBJECTIVE

Internal thoracic artery (ITA) grafting to the left anterior descending artery (LAD) may have catastrophic consequences and can be fatal due to "ITA malperfusion syndrome." We have investigated the efficacy of a second graft in this syndrome.

METHODS

A total of 35 patients, 29 males (82.9%) and 6 females (17.1%), with a mean age of 53.0 +/- 8.7, (range: 38 to 70) undergoing coronary artery bypass grafting required a second supply to LAD due to ITA malperfusion syndrome. This was performed using a saphenous vein graft. The mean number of distal anastomosis was 2.7 +/- 0.45 per patient (range: 1 to 5). The decision for an additional grafting procedure was made in the first operation for 18 patients (51.4%) (Group I). For the remaining 17 patients (48.6%) (Group II), the additional grafting procedures were performed during a reoperation after the development of ischemic complications in the intensive care unit (ICU).

RESULTS

The early mortality rate was 8.6% (3 of 35). Two patients had perioperative myocardial infarction (MI) (5.7%). The second vein graft proved to dramatically reduce the incidence of postoperative MI. Malignant refractory arrhythmias were recorded in 17 patients (48.6%). Twelve patients (34.3%) required inotropic support and seven patients (20%), all in Group II, required intra-aortic balloon pump (IABP) support. The average duration of IABP was 5 days +/- 1.8 days (range: 3 to 7). The necessity of IABP support was found to be statistically higher in the second group compared to the first one.

CONCLUSIONS

Double supply to LAD using an additional saphenous vein graft is the treatment of choice for ITA malperfusion syndrome. The time interval between the first and the second grafts appears to be crucial for postoperative patient outcome.

Internal thoracic artery malperfusion: fast decision for an additional vein graft has impact on patient outcome

BACKGROUND

Internal thoracic artery (ITA) malperfusion has been described as a potentially devastating and lethal complication of coronary artery bypass grafting (CABG). It is our practice to perform an additional vein graft to the distal left anterior descending (LAD) artery in such cases.

METHODS

From August 1999 to July 2002, 2877 CABG procedures were performed at our institution. In 65 patients (2.3%) ITA malperfusion was observed. All of them were treated with an additional vein graft to the distal LAD. All patient data were screened for the time interval between the occurrence of ITA malperfusion and the decision to perform an additional vein graft.

RESULTS

Of 65 patients with ITA malperfusion, 54 patients (83%) survived (group 1), 11 patients (17%) died (group 2). There was no difference in preoperative risk status between the groups. Cross clamp time was 88 +/- 4 minutes in group 1 and 104 +/- 11 minutes in group 2 (p = 0.04). Intraoperative ITA flow to LAD was 6 +/- 1 mL/min in group 1 and 10 +/- 5 mL/min in group 2 (p = 0.2). Time between release of cross clamp and second period of cross clamping was 50 +/- 5 minutes in group 1 and 75 +/- 11 minute group 2 (p = 0.02). Time between termination of cardiopulmonary bypass (CPB) and second period of cross clamping was 23 +/- 3 minutes in group 1 and 46 +/- 7 minutes in group 2 (p = 0.003). Vein graft flow to distal LAD was 54 +/- 4 mL/min in group 1 and 52 +/- 12 mL/min in group 2 (p = 0.5). Maximum postoperative troponin I was 35 +/- 11 ng/mL in group 1 and 136 +/- 32 in group 2 (p = 0.003).

CONCLUSIONS

Survivors of ITA malperfusion had shorter cross clamp times and less myocardial damage as evidenced by lower postoperative troponin I levels. Time intervals between first and second cross clamp and between termination of CPB and second cross clamp were lower in survivors, thus indicating that a fast decision for an additional vein graft may influence postoperative patient outcome.