Optimizing compliance, efficiency, and safety during surveillance of small abdominal aortic aneurysms.

BACKGROUND

Outcome data documenting safety for observation of small abdominal aortic aneurysms (AAA 4.0 to 5.4 cm) are lacking outside of large clinical trials but requires near perfect patient compliance. This study describes a clinical pathway for AAA surveillance using a prospective database utilizing a nurse practitioner oversight to provide efficient use of clinic visits while maintaining a high level of patent participation.

METHODS

Over a 7-year period (June 1999 through June 2006), 334 patients were enrolled in an AAA surveillance pathway at our academic veterans hospital. 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 (>5.4 cm or expansion >1 cm/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 three patients (0.9%) lost to follow-up and two others (0.6%) choosing early repair at civilian institutions. At a mean interval of 29 months (+/-20 mo), surgical repair was performed in 225 (67%) patients by open (n = 143) or endovascular (n = 82) techniques for AAA growth to >5.4 cm (n = 219) or expansion by >1cm/yr (n = 6). One hundred six patients currently remain in surveillance. A single AAA rupture resulting in death occurred during surveillance (0.3%) and perioperative mortality (<60 days) was 0.9% in patients needing intervention for AAA growth. Cumulative aneurysm-related mortality was 0.9% for patients compliant with the AAA surveillance pathway.

CONCLUSIONS

Use of a prospectively-maintained surveillance database managed by a non-physician provider with a reliance on telephone contact resulted in a high degree of patient compliance, reduced unnecessary patient travel, and provided practical clinic use. Limited additional resources were needed to implement our pathway and a similar approach may prove useful for large volume hospital, clinic, or practice systems.