ENDOLEAK AFTER AORTIC STENT GRAFT REPAIR - DIAGNOSIS BY COLOR DUPLEX ULTRASOUND SCAN VERSUS COMPUTED-TOMOGRAPHY SCAN

Purpose: The purpose of this study was to compare the accuracy of a co lor duplex ultrasound scan (CDU) to a computerized axial tomography sc an (CT) in the diagnosis of endoleaks after stent graft repair of abdo minal aortic aneurysms. Methods: The Endovascular Aneurysm Clinical Tr ial Core Laboratory records were reviewed from 117 concurrent CDU and CT studies that were performed in 79 patients who were implanted with the Endovascular Technologies stent graft device between December 1995 and January 1997. All of the studies were interpreted by the Core Lab oratory as having the presence or the absence of an endoleak or as bei ng indeterminate because of technical factors. Of the 117 videotaped C DU studies available for reexamination, 100 were reassessed for techni cal adequacy on the basis of the following criteria: a satisfactory im aging of the aneurysm sac and of the stent graft with gray scale, and both color and spectral Doppler scan evaluation for endoleak outside t he endograft and within the aneurysm sac. Results: Of the 117 studies, 103 CDUs (88%) and 114 CTs (97%) were recorded as having the presence or the absence of an endoleak and 14 CDUs (12%) and 3 CTs (3%) were i ndeterminate. For the studies that were recorded to have the presence or the absence of an endoleak, the sensitivity, the specificity, the p ositive and the negative predictive values, and the accuracy of CDUs a s compared with CTs were 97%, 74%, 66%, 98%, and 82%, respectively. Of the 100 CDU videotaped studies available for review the following res ults were seen: (1) 93 CDUs had satisfactory B-mode images, (2) 76 had satisfactory color Doppler scan images to evaluate for endoleaks, (3) 55 had color Doppler scan assessment of the entire abdominal aortic a neurysm sac for endoleak, and (4) 27 had spectral Doppler scan wavefor m confirmation of suspected endoleaks. Only 19 CDU studies (19%) with all 4 criteria for complete assessment of endoleak were performed. Con clusion: Although most of the CDU studies were technically suboptimal, the CDUs reliably identified endoleaks with an excellent sensitivity and a negative predictive value as compared with CT scans.