[Effect of bypass surgery on the presence and quality of collaterals in coronary heart disease (author's transl)].

The presence and quality of collaterals in coronary angiograms were studied in 89 patients with CHD before and after bypass surgery as well as in 12 unoperated patients who also underwent left heart catheterization twice. Total and local evaluation of collaterals was made in terms of global and regional collateral scores as well as collateral flow rates. Total revascularization generally leads to an entire disappearance of collaterals in the angiogram and represents a criterium for assessing the success of bypass surgery. In non-revascularized as well as unoperated patients, the quality of collaterals improves. This is attributable to additional surgically induced changes in the coronary arteries and progression of the underlying disease, respectively. Partially revascularized patients display no definite changes in total collateral score. In these cases, collaterals to the revascularized regions diminish, whereas those to non-revascularized regions increase. Myocardium not revascularized directly by an aortocoronary bypass graft is thus indirectly revascularized via the secondary appearance of collaterals, which enhance regional perfusion.