PREDICTIVE FACTORS FOR RUPTURE OF THORACOABDOMINAL AORTIC-ANEURYSM

Purpose: To identify the predictive risk factors for rupture of thorac oabdominal aortic aneurysms (TAA). Methods: Thirty-one patients with T AA who did not have the indications for surgical repair of the aneurys m were selected. Inclusion criteria were maximum diameter less than 60 mm, refusal of surgical treatment, and high surgical risk. The select ed patients participated in a prospective follow-up study for a median period of 47 months and underwent at least two thoracoabdominal compu ted tomographic scans a year to measure transverse and anteroposterior diameters. Identification of the predictive factors associated with r upture was undertaken with multivariate analysis by means of Cox regre ssion model. Results: During the study period five patients underwent elective repair, six died of unrelated causes, nine had aneurysms that ruptured (all with diameters greater than 50 mm), and 11 reached the end of the study without rupture or surgical management. Initial anter oposterior diameter and annual growth rate of the anteroposterior diam eter were the variables associated with rupture of the TAA according t o the multivariate statistical analysis by means of Cox regression mod el. Conclusion: We recommend elective repair for a fit patient with as ymptomatic TAA with an initial anteroposterior diameter of 50 mm only when there is an annual growth rate of at least 10 mm. Patients with s imilar diameters but with Smaller annual growth rates should be treate d conservatively and undergo thoracoabdominal computed tomography ever y 6 months. Patients with an initial anteroposterior diameter of 60 mm and an annual growth rate of 6 mm should undergo surgical treatment. These guidelines for elective repair of TAA are based on the results o f a relatively small series and have to be carefully individualized fo r each patient.