Role of Duplex Scan in Endoleak Detection After Endoluminal Abdominal Aortic Aneurysm Repair

Abstract

AbstractObjective: to validate the role of duplex scan in endoleak detection in postoperative surveillance of endoluminal abdominal aneurysm repair (EAAR). Patients and methods between April 1997 and March 1999, 103 patients were eligible for duplex and computed tomography (CT) scan after EAAR. Mean follow-up was 8 months (range 1–24 months). The study protocol comprised concurrent examination with colour-duplex and CT scan at 1, 6, and 12 months after EAAR, for a total of 198 concurrent examinations. All duplex scan examinations were performed by two vascular surgeons with the same machine (ATL HDI 3000). Interobserver agreement in endoleak detection (κ=1) and in type of endoleak (κ=0.7) was evaluated in 50 random duplex examinations. Endoleak detection was examined comparatively in duplex and CT scan, the latter being the gold standard. Sensitivity and specificity tests together with negative- and positive-predictive values (NPV and PPV) were calculated. Results duplex scan was not feasible in one patient. On CT scan the endoleak rate was 4% at one month, 3% at 6 months, and 4% at one year. Overall, CT scan detected 12 endoleaks. With respect to endoleak detection, duplex scan revealed a great ability in ruling out false-negative results (sensitivity 91.7%, NPV 99.4%), but overestimated the presence of endoleak (specificity 98.4%, PPV 78.6%). Regarding type of endoleak, the ability of duplex scan to identify the source of endoleak was low (sensitivity 66.7%). Conclusions duplex scan, if validated, appears to be a reliable means for excluding the presence of endoleak after EAAR