RUPTURE OF ABDOMINAL AORTIC-ANEURYSMS INTO THE MAJOR ABDOMINAL VEINS

Over the period January 1965-July 1992 26 spontaneous fistulas between an abdominal aortic aneurysm (AAA) and the major abdominal veins were observed and surgically treated. Twenty-two were aorto-caval, one ili aco-iliac and 3 aorto-iliac; since clinical features, pathophysiology, principles of surgical treatment and postoperative care are similar, both the conditions are considered as a single disease (aorto-caval fi stula: ACF). The incidence among 373 ruptured AAA operated in emergenc y conditions in the same period was 6.97%, with an operative mortality rate of 34,61% compared to an overall mortality for ruptured AAA of 3 4.85%. All subjects were males with a mean age of 67.3 years. Twelve s ubjects showed shock at admission (46.1%): the mortality rate in this subgroup was 50% compared to 21.4% among the non-shocked patients. Pai n was always present, oedema of one or both of the lower limbs in 9 ca ses (34.6%) and abdominal bruit or murmur and thrill in 16 (61,5%). On e patient died at laparotomy for irreversible cardiac arrest; the 25 c ompleted procedures consisted of endoaneurysmal repair of the fistula under venous bleeding control by digital compression and prosthetic re placement of the abdominal aorta (7 straight and 18 bifurcated grafts) . Intraoperative mean blood losses exceeded 4,000 ml, but autotransfus ion, available only in 12 procedures, allowed significant sparing of h eterologous blood units. The mortality rate was not clearly improved b y autotransfusion, but among these 12 patients shock was present in 7 instances (58.3%), compared to 5 out of 14 subjects (35.7%) operated o n before autotransfusion devices were available. Paradoxical pulmonary embolism (PE) never occurred in this series, while postoperative PE w as a major complication in 5 cases, three of which occurred among the subjects presenting with preoperative oedema of the lower limbs. Multi ple organ failure was the most important cause of death in this series . Early recognition and surgical operation, together with appropriate postoperative intensive care, are the key for successful treatment of ACF.