Abdominal aortic aneurysms: Efficacy of sonography for preoperative assessment

Objective: To investigate the efficacy of sonography for preoperative assessment of abdominal aortic aneurysms. Methods: A series of 101 consecutive patients with abdominal aortic aneurysm who were scheduled for elective surgery were prospectively examined with sonography before the operation. The operators were blinded to the results of previous imaging examinations. Findings at sonography were correlated with findings at laparotomy. Results: The aneurysm was correctly identified in all of 101 patients. The mean difference between sonographic and surgical measurements of the maximum diameter of the aneurysm was 0.5 cm. The right and the left renal arteries were identified in 65/101 patients and 68/100 patients, respectively (one patient had previously undergone left nephrectomy). The left renal vein was found by the surgeon in the anteaortic position in 94 cases and in the retroaortic route in 6. The sensitivity and the specificity of sonography in recognizing the retroaortic location of the left renal vein were 60% and 100%, respectively. In 92/101 cases (91%) the supra-, juxta- or infrarenal location of the aneurysm was correctly evaluated with sonography. Sonography correctly identified the inflammatory nature of the aneurysm in 9 of 13 cases; two false positive diagnoses of inflammatory aneurysm were made (sensitivity, 69%; specificity, 98%). The sensitivity and specificity of sonography in demonstrating the presence of associated iliac artery aneurysms were 83% and 97%, respectively. Conclusion: Ultrasonography provides a reliable preoperative assessment of abdominal aortic aneurysms.