Indicators of Survival after Open Repair of Ruptured Abdominal Aortic Aneurysms and an Index for Predicting Aneurysmal Rupture Potential

Abstract

Introduction Despite the increased number of cases of elective abdominal aortic aneurysm (EAAA) repair, the number of patients with ruptured AAA (RAAA) has not significantly reduced in the past decade.1) Further, although the mortality rate following EAAA repair has steadily improved by about 1%-6%, 2) the mortality rate after RAAA repair has not significantly changed in the last three decades and is still in the 30%-70% range. 3, 4) Many factors, including age, comorbidity, medical condition, preoperative shock or hypotension, increased creatinine level, low hemoglobin or hematocrit level, and technical and postoperative complications, are considered predictors of death, but none of these correctly predict the outcome of patients with RAAA. 5-7)The maximum transverse aneurysmal diameter has been the only criterion used to predict aneurysmal rupture potential in the last 40 years.8) According to this criterion, aneurysms reaching 5-5.5 cm in diameter are generally recommended for repair. 9) However, there are many reports of rupture of aneurysms smaller than 5.5 cm in diameter; the estimated rupture rate of small aneurysms varies between 4.6% and 23%.10) On the other hand, the incidental presentation of extremely large asymptom- Results: The mortality rate was 18.6% (8/43). The ratio between the maximum aneurysmal diameter and the length (along the central axis) from the aneurysmal neck to the point at which the diameter was threefourth of the maximum aneurysmal diameter was used as an index to predict aneurysmal rupture potential. The index score was 2.7 ± 1.2 in the RAAA and 1.9 ± 0.9 in the EAAA (p = 0.018). For aneurysms of ≤ 6-cm diameter, the index score was 3.0 ± 1.0 in the RAAA and 1.8 ± 0.9 in the EAAA (p = 0.03). All patients in the EAAA except one had an index score of < 2.3 and 6 of the 7 patients with RAAA had a score of > 3. Indicators of Survival after Open Repair of Ruptured Conclusions:The results suggest that patients with AAA having scores of > 3 are at high risk of rupture. This index would be useful for decision making regarding repair of AAA, especially in the borderline cases.