Duplex ultrasonography and its impact on providing endograft surveillance.

Increasingly, aortic aneurysms are being repaired using endoluminal grafting techniques. Complications of such surgery include persistent endoleaks, continued growth of the aneurysm and migration or thrombosis of the device. Consequently, patients undergoing endovascular repair must be under rigorous surveillance postoperatively. Spiral computed tomography scanning is the test of choice to assess the integrity of the repair, but frequent scanning subjects the patient to repeated doses of radiation and nephrotoxic contrast agents. Duplex ultrasound has long been used to diagnose the presence of aortic aneurysm and may be an appropriate tool for monitoring endovascular grafts. However, the wide variability in sensitivity, specificity, positive and negative predictive values, and accuracy rates described in the literature reflect the fact that many problems still exist with this technique. Until these difficulties can be resolved, duplex ultrasonography is best used in conjunction with spiral computed tomography.