Many vascular specialists are waiting for the results of the European randomised controlled trials to see whether EVAR will become the gold standard treatment for aneurysm repair. Or will the main EVAR indication be limited to those patients who are unfit for open repair? Now a US trial has belatedly got underway to answer these same questions. In the same way that the US-based Aneurysm Detection and Management Study (ADAM) trial followed the UK Small Aneurysm Trial, now the Open Versus Endovascular Repair (OVER) for abdominal aortic aneurysms (AAAs) trial is following the UK’s EndoVascular Aneurysm Repair (EVAR) and the Dutch Randomised Endovascular Aneurysm Management (DREAM) trials.

OVER is a multicentre comparison trial being funded by the department of Veterans Affairs Co-operative Study Group. Vascular News asked Dr Frank Lederle, Professor of Medicine at the Minneapolis VA Medical Center and trial coordinator, how the OVER trial is progressing.

“The Veterans Affairs Open Versus Endovascular Repair (OVER) Trial for Abdominal Aortic Aneurysm began recruitment on 15th October, 2002, and to date [5th February, 2003], 26 patients have been randomised,”said Lederle.

The recruitment target for the trial is 1,260 patients although Lederle admitted, “We are well behind the target rate at present, but it is very early and some centres are still not ready with their IRB [Institutional Review Board] approvals etc.”OVER enrolment is scheduled to run for four and a half years and one-year follow-up data will be published when available on all patients. Follow-up is due to end at 8 years (15th October, 2010).

Lederle explained why OVER has had a slow start, “EVAR is available in the US (and in the VA Medical Center) outside of the trial and this has complicated recruitment, because patients consider that if both treatments are OK, they would prefer EVAR.”

Vascular News asked him if he could foresee any other potential problems in the recruitment of patients to the OVER trial. Currently centres would only be expected to have about two patients randomised each, so we do not yet know how it will go,”Lederle responded.

Meanwhile, EVAR 1 is recruiting ahead of schedule and EVAR 2 is on target. EVAR recruitment ends on the 31st of December 2003 and EVAR 1 30-day mortality results will be published in June 2004. EVAR’s data monitoring and ethical committee has indicated that a result is expected.