Colour Doppler diagnosis of perigraft flow following endovascular repair of abdominal aortic aneurysm.

BACKGROUND: Endovascular repair of abdominal aortic aneurysm is a relatively new surgical technique which is less invasive than conventional open abdominal surgery but is associated with a significant specific complication of endoleak. The aim of this study was to determine the accuracy of duplex ultrasound imaging, utilising colour Doppler, as the primary method for post surgical monitoring of endovascular aneurysm repair. METHODS: Experimental design: a case cohort study of 45 patients undergoing endovascular repair of abdominal aortic aneurysm. Setting: angiography, CT scanning and surgery performed at Westmead Hospital, a teaching hospital of the University of Sydney; patients followed postoperatively at the Westmead Vascular Laboratory, a dedicated vascular diagnostic ultrasound facility. Patients: Forty males and five females, mean age 69.1 years (range 51 to 84). Interventions: patients underwent attempted insertion of an EVT (endovascular prosthesis) for exclusion of abdominal aortic aneurysm (mean diameter 5.3 cm; range 4.0 to 8.4 cm). Conversion to open repair was required in three cases (6.6%). An aorto-biliac graft was inserted in 28 patients, a tube graft in eight and an aorto-unilateral iliac graft with femorofemoral (or ilioilial) crossover graft in six. Measures: patients were followed over a period of 53 months (median follow-up time 15 months) with 106 colour Doppler scans of 39 endovascular grafts (mean of 2.9 scans per patient). RESULTS: All aneurysms decreased in diameter (range 0.1 cm to 4.3 cm, mean 0.9 cm). Abnormal flow in the residual aneurysmal sac was found in three patients. In all three cases of endoleak the colour Doppler diagnosis was supported by CT scan and confirmed on angiography. The CT scans did not provide any additional information to that obtained by colour Doppler imaging. CONCLUSIONS: Colour Doppler provides an effective means of non-invasive follow-up assessment of patients who have had endovascular repair of abdominal aortic aneurysms.