Mortality from ruptured abdominal aortic aneurysm

A meta-analysis of 50 years of ruptured abdominal aortic aneurysm repair

BACKGROUND

Operative repair of ruptured abdominal aortic aneurysm (RAAA) is associated with a high mortality rate but reported figures vary widely. The aim of this study was to estimate the operative mortality of RAAA repair and determine how it has changed over time.

METHODS

A meta-analysis of all English language literature quoting figures for operative mortality of RAAA repair.

RESULTS

The pooled estimate for the overall operative mortality rate of RAAA repair from 1955 to 1998 was 48 (95 per cent confidence interval 46 to 50) per cent. Meta-regression analysis of operative mortality over time demonstrated a constant reduction of approximately 3.5 per cent per decade (1954-1997) with an operative mortality rate estimate for the year 2000 of 41 per cent. Seventy-seven studies reported intraoperative mortality but, while this appears to have remained constant over time, there was evidence of the presence of publication bias in the subgroup of papers reporting this outcome. There was no evidence of publication bias for the overall operative mortality outcome.

CONCLUSION

Contrary to the conclusion of recent studies, this paper demonstrates a gradual reduction with time in the operative mortality rate of RAAA repair.

Ruptured abdominal aortic aneurysms: factors affecting mortality rates

Outcome of 113 operations for ruptured abdominal aortic aneurysms were reviewed to determine the contribution of perioperative events to mortality rates. Preoperative, intraoperative, and postoperative factors were examined with regard to their influence on early and late deaths. A mortality rate of 64% (72/113) was unrelated to age, gender, and preexistent medical conditions. Death within 48 hours occurred in 42 of 72 patients (58%). Preoperative status, including cardiac arrest, loss of consciousness, and acidosis influenced early deaths (less than 48 hours) but not late deaths. Early deaths were also influenced by severe operative hypotension and excessive transfusion requirements. Late deaths (greater than 48 hours) occurred in 30/72 cases (42%) at a mean of 24.6 +/- 22.9 days. Late death was related to postoperative organ system failure, specifically renal and respiratory failure, and the need for reoperation. The overall mortality rate was influenced by preoperative, intraoperative, and postoperative factors. Postoperative renal failure was the strongest predictor of overall deaths. Survival after ruptured abdominal aortic aneurysm depends on intraoperative and postoperative complications as well as preoperative conditions. Late death, the greatest strain on resources, is independent of preoperative status. The thesis that some patients with ruptured abdominal aortic aneurysm should be denied operation to conserve resources is not supported by these data. Efforts to improve survival should focus on reducing intraoperative complications and improving management of postoperative organ failure.

Abdominal aortic aneurysms: should they all be resected?

A retrospective study has been carried out on 124 consecutive patients with abdominal aortic aneurysms admitted during the period 1960-74. The mortality rate after emergency operation was 56 per cent and after elective operation 15 per cent. As in other vascular centres during these years the mortality rate has decreased among electively operated patients. We have tried to answer two questions: which patients without signs of rupture should undergo operation and which patients with a ruptured aneurysm should not be operated upon?

Survival improvement following aortic aneurysm resection

Abdominal aortic aneurysm resections were performed on 298 patients between January, 1966 and December, 1973. The results were compared with 186 resections previously reported between 1955-1965. Hospital mortality rates for elective resections were 13% in 1955-1965, 8.4% in 1966-1973, and 4.2% in the 113 patients treated during the last 3 years. Urgent resections for intact aneurysms, previously associated with a 36% mortality, resulted in a 6% mortality rate in 1966-1973. The emergency resection mortality rate for ruptured aneurysm, originally 69%, was reduced to a present day over-all mortality of 55%, and 42% for the last 3 years. Calculated actuarial survival at 5 years was 65% for urgent (intact), 60% for elective and 40% for emergency (ruptured) groups. Atherosclerosis remains the major deterrent to long-term survival with myocardial infarction and stroke causing 43% of deaths occurring within 5 years. Improved survival appeared secondary to better operative technique, postoperative patient monitoring, increased surgical experience, and more elective resections of smaller, asymptomatic aneurysms than in 1955-1965. With present day low mortality rates, elective resection should be recommended in all patients without significant medical contraindications.

Disseminated intravascular coagulation as a complication of abdominal aortic aneurysm repair

A retrospective review was done of all patients undergoing surgical repair of abdominal aortic aneurysm (AAA) on whom coagulation studies were obtained. Those patients with laboratory documented disseminated intravascular coagulation (DIC) were selected and their clinical records reviewed. This included 7 patients studied in the periods 1964-1965 and January 1971-July 1973. Of these 7 cases, 4 occurred in patients undergoing emergency operation for ruptured aneurysm and 3 were in elective cases. All 7 patients exhibited clinical evidence of abnormal bleeding, while 6 of the 7 progressed rapidly to renal shutdown. The seventh patient recovered spontaneously. Of the 6 patients with full blown clinical and laboratory evidence of DIC, 2 recovered. Both cases received heparin therapy and multiple hemodialyses. A third patient was started on heparin but died at 36 hours in heart failure. All 3 patients receiving heparin showed clinical cessation of abnormal bleeding and disappearance of soluble fibrin monomer complexes within 24 hours of starting therapy. The study suggests a higher incidence of DIC than has previously been appreciated in both the emergency and elective repair of AAA. The prompt recognition and treatment of this complication may reverse the abnormal intravascular clotting, minimize its more serious results and avoid futile and dangerous operative intervention.

Abdominal aortic aneurysms: special problems

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