2007 Abstracts: Optimizing Compliance, Efficiency, and Safety During Suveillance of Small Abdominal Aortic Aneurysms

Background: Outcome data documenting safety for observation of small abdominal aortic aneurysms (AAA 4.0-5.4 cm) are lacking outside of large clinical trials but requires near perfect patient compliance. We implemented a clinical pathway to streamline AAA surveillance using a prospective database, nurse practitioner oversight, 'one-stop' imaging and evaluation, minimized follow-up clinic visits, and primary reliance on telephone communication.
Methods : From 1998 to 2006, 334 patients were enrolled in a AAA surveillance pathway at our academic Veterans hospital that serves 6 counties spanning 250 miles. To minimize patient travel, clinic visitation was reserved for an initial examination with patient education and for discussion of intervention options in patients demonstrating AAA growth (> 5.4cm or expansion > 1cm/yr) during follow-up. Biannual ultrasound or CT imaging was scheduled and results discussed (after physician review) via telephone or 'same day' direct patient contact. An electronic database was used to update patient information and plan follow-up.
Results : Compliance with the AAA surveillance pathway was achieved in 98.5% of patients, with only 3 patients (0.9%) lost to follow-up and 2 others (0.6%) choosing early repair at civilian institutions. At a mean interval of 29 months (+ 20mo), surgical repair was performed in 225 (67%) patients by open (n=143) or endovascular (n=82) techniques for AAA growth to > 5.4cm (n=219) or expansion by > 1cm/yr (n=6). One hundred nine patients currently remain in surveillance. A single AAA rupture resulting in death occurred during surveillance (0.3%) and perioperative mortality (<60 days) was 1.3% in patients needing intervention for AAA growth. Cumulative aneurysm-related mortality was1.2% for patients compliant with the AAA surveillance pathway.
Conclusions : Use of a prospectively maintained database for follow-up, reliance on telephone contact, reduction of unnecessary patient travel by efficient clinic use, and management by a non-physician provider was associated with optimal patient compliance and rare AAA-related adverse events during surveillance of small AAA. Limited additional resource utilization was needed for our pathway and a similar approach may prove useful for large volume hospital, clinic or practice systems.