Coronary arteriopathy after lymphatic blockade: an experimental study in dogs

The effects of lymph stasis on the histological and biochemical properties of the coronary arterial wall and on the coronary circulation were studied in 72 dogs. Cardiac lymph stasis was produced in 52 dogs by cardiac lymphatic blockade whereas in 20 dogs only a sham operation was performed. Blockade of cardiac lymph drainage promoted characteristic injury to the coronary arteries including subendothelial edema with plasma inbibition, interstitial and intracellular edema in the tunica media with degeneration in the smooth muscle layer, swelling of the adventitial space with dilated lymph vessels and, later, fibrosis. The biochemical properties of the coronary arterial wall also were adversely affected by cardiac lymph stasis. Thus, the collagen and hexosamine content of the coronary arteries increased and the metabolism of the coronary wall shifted in an anaerobic direction. Whereas coronary blood flow was slightly decreased with lymph blockade, the coronary circulatory reserve capacity and the adaptability of the coronary vascular system was markedly reduced. The histological changes were most apparent in the smaller coronary arteries. The coronary microvasculature was also pathologically altered with the development of numerous coronary arteriovenous microshunts. These findings in conjunction with other experimental and clinical information suggest that impaired cardiac lymph drainage contributes to the pathogenesis and progression of coronary artery disease.