Is thrombosis of the infrarenal abdominal aortic aneurysm an acceptable alternative?

Abstract

Aortic aneurysm thrombosis with extra-anatomic bypass has been proposed for persons with infrarenal aortic aneurysms who are “too debilitated” to undergo standard aortic reconstruction. Thirteen patients (mean age, 75 years) were selected between January 1980 and June 1984 for axillobifemoral bypass with bilateral iliac artery occlusion to manage their infrarenal aortic aneurysms (mean size, 6.3 cm; range, 4.9 to 7.5 cm). Preoperative risk factors were cardiac (angina, compensated congestive heart failure, and significant preoperative arrhythmias), 100% of patients; pulmonary (symptomatic chronic obstructive pulmonary disease with a 1-second forced expiratory volume less than 50% of the predicted value), 46% of patients; renal (creatinine value greater than or equal to 2.0 mg/dl or creatinine clearance less than 20 ml/min), 46% of patients; or nutritional (albumin less than or equal to 3.5 gm/dl or body weight less than 90% of ideal), 46%. Ninety-two percent of the patients had two risk factors whereas 46% had three or more risk factors. The operative mortality rate was 31%; three patients died of multisystem organ failure and another died of thrombin-induced consumptive coagulopathy and hemorrhage. (Our operative mortality rate for conventional graft replacement of abdominal aortic aneurysms is less than 3%.) Morbidity in persons surviving at least 1 month included thrombosis of the extra-anatomic bypass graft requiring thrombectomy (three patients), ischemic colitis (two patients), ischemic neuropathy (one patient), and bilateral above-knee amputations (one patient). Thrombosis of the aneurysm was not achieved in two patients despite use of fluoroscopically controlled embolization of runoff vessels. Sixty-nine percent of patients survived 1 month, 54% survived for 2 months, and 31% were alive at 6 months after operation. One woman died 6 months postoperatively when her infrarenal aneurysm ruptured. Another person survived the emergent repair of her ruptured aneurysm 3 months after the “thrombosis” and is alive and well 1 year after the operation. One patient died 15 months after operation of an unknown cause. Each person whose aneurysm ruptured had radiographic confirmation of thrombosis of the aneurysm. When compared with the morbidity and mortality associated with untreated abdominal aortic aneurysms, the excessive morbidity and mortality that occurred in these high-risk patients indicated that aneurysm thrombosis with bypass was not an acceptable technique of management.