Duplex ultrasound as the sole long-term surveillance method post-endovascular aneurysm repair: a safe alternative for stable aneurysms.

OBJECTIVE

Long-term surveillance with computed tomography (CT) after endovascular aneurysm repair (EVAR) increases both cost and risk. The purpose of this study was to evaluate the safety of an alternative follow-up modality with color flow duplex ultrasound scanning (CDU) as the sole method of imaging.

METHODS

In 2003, we initiated a new follow-up (FU) schedule with yearly CDU as the sole imaging method for selected patients. Indications included a residual sac of less than 4 cm, expanded later to stable sac size for more than 2 years. A stable type II endoleak was not a contraindication. CT scans were obtained selectively-based on suspicious findings of a new endoleak or enlarging sac on CDU. The records of all patients with at least 1 year FU under this schedule were reviewed.

RESULTS

One hundred eighty-four patients were followed with CDU only for 1 to 4 years for a mean of 24 +/- 13 months. The new schedule was initiated at a mean of 34 +/- 24 months after EVAR (range 1-112 months). Twenty-three patients had previous endoleaks that had resolved spontaneously or had been treated. During CDU FU, three new endoleaks were detected, one with sac enlargement. All prompted CT evaluation: one type II endoleak with stable sac size could not be identified on CT 3 months later, and two distal type I endoleaks that required limb extension. All three had a prior Ancure endograft. No ruptures or graft occlusions were noted. One abdominal aortic aneurysm (AAA) related death followed graft explantation for infection. There were two additional deaths from malignancy and two from cardiac causes. After the FU switch, freedom from endoleaks was 96%, and from secondary interventions 95% at 48 months by life table method. Mean AAA diameter at baseline was 54 +/- 8 mm and decreased to 40 +/- 11 mm before the switch to CDU only FU. At last FU mean aneurysm diameter was 39 +/- 11 mm. When the current switch criteria were applied to a consecutive series of 200 EVAR patients, 97% would have been eligible for CDU only surveillance by 3 years postoperatively.

CONCLUSIONS

CDU only surveillance post-EVAR is safe and can be initiated early after treatment in patients with shrinking or stable aneurysms. This policy should result in cost savings advantage and avoid the complications associated with CT.