Value of routine computed tomography in the preoperative assessment of abdominal aneurysm replacement

This study compares the findings of conventional computed tomography (CT) a nd ultrasound (US) imaging in the preoperative evaluation of patients with abdominal aortic aneurysm (AAA). It also assesses the impact of preoperativ e CT-derived information on operative strategy. A prospective study was con ducted of 96 patients who were considered for aortic aneurysm surgery, and the operative notes and US and CT reports were analyzed to assess correlati on of findings and influence of CT on operative tactics. Agreement between CT and US in sizing the aneurysm was generally good. CT was more accurate t han US for defining the upper and lower extent of the aneurysm (75% and 83% , respectively, with CT, compared to 47% and 41% with US), although it had a high false positive rate (48%) for juxtarenal disease. Its advantage over US in regard to showing other intraabdominal pathology was only marginal, and it predicted an inflammatory reaction in only two of the five cases. It s influence on operative strategy was minimal: Of the 25 cases where a juxt arenal aneurysm was predicted by CT, only 2 patients did not have surgery a s a result. CT is a relatively expensive and time-consuming procedure, and its ionizing radiation, however small, and potential side effects from cont rast material hypersensitivity cannot be ignored. In light of the above fin dings, we suggest that CT scanning need not be routinely employed in the pr eoperative workup of elective aortic aneurysm repair but should be used onl y in selected cases.