Microcirculatory characteristics in patients with Buerger's disease.

The most characteristic pathophysiologic change in Buerger's disease or thromboangiitis obliterans (TAO) is considered the breakdown of microcirculation in the extremity, but this has not yet been proven. The purpose of this study is to examine the damage of microcirculation in TAO objectively, by means of intra-arterial injection of two kinds of radioisotope. In 7 TAO and 4 infrainguinal arteriosclerosis obliterans (ASO) patients, thallium 201 chloride (201Tl) and 99mTc macroaggregated human serum albumin (99mTc-MAA) were administered through bilateral common femoral artery injections. In the planar image of the foot, rectangular regions of interest (ROIs) were placed on the foot muscles and toes. Normalized counts of 99mTc-MAA in each ROI were divided by that of 201Tl, and the result was defined as the microcirculation damage index, based on their different kinetics. The damage index of the foot muscle was not different between ASO and TAO, but that of the toe was lower in TAO than ASO patients. Lumbar sympathectomy was performed in 5 TAO patients, but it did not improve the damage index. It is concluded that there is breakdown of the microvascular defense system from the beginning of the disease, and critical ischemia make the regional cell function deteriorate as if a precursor to a trophic lesion. Lumbar sympathectomy did not immediately improve microcirculation.