IS THE INTERNAL THORACIC ARTERY THE CONDUIT OF CHOICE TO REPLACE A STENOTIC VEIN GRAFT

Reoperative coronary artery bypass grafting secondary to saphenous vei n graft (SVG) stenosis is a mushrooming problem. The internal thoracic artery graft (ITA) provides superior long-term patency, but its now i s limited and may be inadequate to meet large myocardial demands. To e valuate the efficacy of the ITA as a replacement conduit for a stenoti c SVG, 387 consecutive patients undergoing reoperative bypass grafting from 1985 to 1990 with a stenotic SVG to a totally obstructed left an terior descending coronary artery (LAD) were analyzed. The patients we re divided into four groups according to the management of the previou sly placed SVG. Group I (n = 155) underwent graft replacement with a n ew SVG. Group II (n = 90) received an ITA with the old SVG left intact . In group III (n = 37), an ITA was placed to the LAD with an SVG to t he diagonal (old graft interrupted). Group IV (n = 104) had an ITA onl y to the LAD (old graft interrupted). There were 14 deaths (3.6%). Mor tality rate was 7.9% for group IV and 2.1% for groups I through III (p = 0.01). Multivariate analyses identified advancing age (p = 0.001), ITA only (p = 0.001), and female sex (p = 0.04) as independent predict ors of operative mortality. Evidence of hypoperfusion in the distribut ion of the LAD was present in 19 patients, all of whom were in group I V (18.9%). Predictors of hypoperfusion were moderate/severe left ventr icular function (p = 0.02) and ITA to the LAD with interruption of the old graft (p = 0.0001), Hypoperfusion syndrome was treated with a new SVG to the LAD in 11 patients, and all but I survived; 8 were treated with an intraaortic balloon pump, for a 63% mortality (p = 0.01). We conclude that replacing a stenotic SVG to a totally occluded LAD with an ITA is associated with increased mortality and increased incidence of hypoperfusion syndrome. Hypoperfusion syndrome is best treated with supplemental vein grafting.