The pulmonary vascular lesions of intravenous drug abuse

Abstract

We examined microscopic sections of lungs from 70 autopsies on persons who abused drugs by intravenous injection in order to evaluate systematically the spectrum of pulmonary vascular lesions resulting from this practice. Angiothrombosis, the most frequent pulmonary vascular lesion, occurred in 13 instances. Morphologic subgroups of this category include weblike and eccentric intimai fibrous lesions, “plexiform-like” lesions, and aneurysmally dilated, tortuous small vessels. Thrombotic changes typically are induced by intravenous injections of solutions derived from tablets or capsules that ethically are intended for oral consumption, because oral pharmaceutical preparations usually contain insoluble microcry-stals such as talc, starch, or cellulose. Ordinary illicit heroin does not contain enough insoluble crystalline debris to induce extensive pulmonary angiothrombosis. We found only two specimens with vascular changes indicative of nonthrombotic pulmonary hypertension; one of these persons had concomitant cirrhosis of the liver, and the other had aortic and mitral valvular bacterial endocarditis. Morphometric studies of the muscular arteries in all other lung samples containing scant embolic foreign material did not show a significant difference between drug abusers and normal control subjects, a finding that fails to support the hypothesis that vasoconstriction or other nonthrombotic reactions to intravenous drug abuse cause pulmonary hypertension and cor pulmonale.