Diverse morphologic manifestations of cardiac allograft vasculopathy: a pathologic study of 64 allograft hearts.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a major limitation to the long-term success of cardiac transplantation. Although there are published descriptions of the lesions, there have been no studies delineating the pathology of CAV in a large series of patients who underwent retransplantation for CAV. METHODS: We reviewed archival records and microscopic sections of surgically explanted hearts from 64 patients who underwent cardiac retransplantation: 54 adults (18 to 70 years old) and 10 children (3 to 15 years old). Vascular lesions were categorized as showing intimal fibromuscular hyperplasia, atherosclerosis and/or inflammation. The degree of luminal narrowing was estimated from gross descriptions and microscopic sections. RESULTS: In total, 75% of hearts had evidence of acute cellular rejection, mostly mild. Intramyocardial arteries showed primarily intimal fibromuscular hyperplasia and inflammation with no atheromas present. Large and branch epicardial coronary arteries were narrowed in at least one artery of all hearts. Lesions in the epicardial coronary arteries were composed of intimal fibromuscular hyperplasia, atherosclerosis and/or inflammation affecting one or more vascular layers (intima, media and adventitia). Severe CAV with >75% luminal narrowing was seen in the LAD in 17% of hearts, the LCx in 17% and the RCA in 22% of hearts. Two hearts had severe narrowing of the left main coronary artery. Nineteen arteries had luminal thrombi. All hearts had narrowing of smaller epicardial branch coronary arteries that was often severe. Atheromas were present in arteries of adults and children; thus, not all atheromas could be considered pre-existing prior to transplantation. Both arteries and veins showed intimal hyperplasia and inflammation. CONCLUSIONS: CAV is a pathologically multifaceted disorder that affects large and small epicardial coronary arteries of adults and children, with different types of lesions: intimal fibromuscular hyperplasia; atherosclerosis; and/or inflammation (vasculitis). Therapies to address this disease must take into account the protean nature of the vascular lesions.

Long-term experience of girdling the ascending aorta with Dacron mesh as definitive treatment for aneurysmal dilation.

BACKGROUND: The management of the mildly to moderately dilated ascending aorta (3.5 to 4.9 cm) in cardiac surgery remains controversial. Therapeutic options have included radical aortic resection with synthetic graft substitution, external aortic reinforcement or wrap, with or without partial aortic wall excision, and a watch-and-wait approach. We reviewed our institutional experience with Dacron (DuPont, Wilmington, DE) mesh wrap support of dilated ascending aortas. METHODS: During the last 20 years, 102 patients with aneurysmal dilatation of the ascending aorta underwent wrapping of the ascending aorta with a fine Dacron mesh from the ventricular-aortic junction to the origin of the innominate artery. For the last 10 years, the wrap was anchored to the aortic annulus with pledgeted sutures. Aortic diameters up to 6 cm, without focal areas of thinning, were wrapped. Aortic diameters exceeding 6 cm, or with focal thinning, underwent tailored aortic wall resection and wrapping. Primary end points of the study included mortality, aortic diameter growth, dissection or rupture, or both. RESULTS: The mean age of the group was 54.7 +/- 19 years (range, 12 to 90 years). A single patient underwent aortic wrapping without cardiopulmonary bypass. Sixty-six patients (65%) required additional aortic valve surgery. Five patients (5%) had reinforcement of dilated sinuses with glutaraldehyde-treated pericardial patches combined with wrapping. Twenty-seven patients (26%) had combined coronary and valve surgery, and 2 patients had coronary revascularization alone. There was neither early nor hospital mortality. Among the 81 patients (79%) we were able to contact, 7 (7%) late deaths had occurred at 0.5, 1, 3, and 9 years after operation that were unrelated to aortic pathology. Various levels of follow-up were obtained in the 88 patients (86.2%). In 78 patients, echocardiograms, computed tomography angiograms, or magnetic resonance angiograms were obtained. In 2 of these patients, aneurysmal dilatation of the sinuses developed below the wrap and reoperation was required. No patient in whom the mesh wrap was anchored to the aortic annulus required reoperation. All 81 patients that were contacted by us and monitored by referring physicians were asymptomatic and free of problems related to the aorta. The mean (+/- SD) preoperative diameter of the ascending aorta was 49.2 +/- 7.8 mm (range, 35 to 87 mm), the postwrap intraoperative diameter was 32.9 +/- 3.4 mm (range, 20 to 40 mm), and the follow-up postoperative aortic diameter was 35.6 +/- 12.7 mm (range, 27 to 52 mm). The mean average change in the aortic diameter during the follow-up period was 2.6 +/- 14.8 mm (range, -7 to 22 mm), a mean of 8%. The mean follow-up period was 5.7 years (median, 4.77 years; range, 9 days to 21 years). There were no infections or other early complications related to the wrap. CONCLUSIONS: Dacron mesh support of the moderately dilated aneurysmal ascending aorta, alone or in conjunction with coronary revascularization, aortic root surgery, or valvular operations, or both, is safe and durable. Dacron mesh is transparent and stretchable, permitting tight girdling of the aorta. These properties prevent hematoma formation, facilitate proximal vein graft anastomoses, and provide visualization and access to aortic suture lines. Finally, this technique retards further aortic dilation, altering the natural history of aortic aneurysms.