Comparison of surveillance vs Aortic Endografting for Small Aneurysm Repair (CAESAR) trial: study design and progress. Quality of life, impotence, and activity level in a randomized trial of immediate repair versus surveillance of small abdominal aortic aneurysm. Fit patients with small abdominal aortic aneurysms (AAAs) do not benefit from early intervention.
The CAESAR Trial aims to assess the outcome of endovascular repair (EVAR) vs surveillance of small abdominal aortic aneurysms (AAA) with maximum diameter of 4.1-5.4 cm on computerised tomography (CT) scan.
                Patients between 50 and 80 years of age, with small AAA, anatomically suitable for EVAR, are randomly allocated to early EVAR or surveillance. The primary outcome measure is survival. Secondary endpoints include: aneurysm-related deaths (defined as any death caused directly or indirectly by rupture or endovascular/open aneurysm repair), AAA rupture, peri-operative or late complications, conversion to open repair, complications associated with delayed treatment including loss of treatment options, AAA growth rates and quality of life. Target recruitment is 740 patients to show that early EVAR is associated with a 15% survival benefit at 54 months.
                Randomization started in September 2004. By the end of April 2005, 86 patients had been enrolled by 10 active European centres. Completion of recruitment is expected for September 2006 and publication of the results in mid 2007. We compared long-term health-related quality-of-life outcome after randomization to immediate elective repair or imaging surveillance, and in relation to time of elective repair, in patients with small asymptomatic abdominal aortic aneurysm (AAA).
                This randomized clinical trial was carried out in 16 Veterans Affairs medical centers. Study subjects were patients at good surgical risk, aged 50 to 79 years, with AAAs 4.0 to 5.4 cm in diameter. Interventions included immediate open surgical AAA repair or imaging surveillance every 6 months with repair reserved for AAAs that became symptomatic or enlarged to 5.5 cm. Main outcome measures considered were SF-36 health status questionnaire, prevalence of impotence, and maximum activity level, which were determined at randomization and at all follow-up visits.
                Eleven hundred thirty-six patients were randomized and followed up for 3.5 to 8 years (mean, 4.9 years). The two randomized groups did not differ significantly for most SF-36 scales at most times, but the immediate repair group scored higher overall in general health (P <.0001), which was particularly evident in the first 2 years after randomization, and slightly lower in vitality (P <.05). The baseline value of one SF-36 scale, physical functioning, was an independent predictor of mortality. Overall, more patients became impotent after randomization to immediate repair compared with surveillance (P <.03), but this difference did not become apparent until more than 1 year after randomization. Maximum activity level did not differ significantly between the two randomized groups, but decline over time was significantly greater in the immediate repair group (P <.02).
                For most quality-of-life measures and times there was no difference between randomized groups. Immediate repair resulted in a higher prevalence of impotence more than 1 year after randomization, but was also associated with improved perception of general health in the first 2 years. The UK Small Aneurysm Trial (UKSAT) and the American Aneurysm Detection and Management (ADAM) trial both concluded that early elective open surgery does not confer any late survival advantage in patients with small abdominal aortic aneurysm (AAA) with diameter 4.0 to 5.5 cm. However, two trials of endovascular aneurysm repair in small AAA have started based upon speculation that a sub-group of particularly fit patients, with low operative mortality, may benefit from early intervention. Here we investigate whether the fittest patients from the UKSAT might have benefited from early intervention.
                A total of 1090 patients randomized into the UKSAT between 1991 and 1995 were followed for an average of 12 years for mortality. Baseline data were used to calculate the Customized Probability Index (CPI), a validated prognostic risk score for operative mortality after elective open aneurysm repair that assigns risk points for history of cardiac, pulmonary, and renal disease and subtracts risk points for use of statins and beta-blockers. Cox regression was used to assess any differences in all-cause or aneurysm-related mortality between policies of early surgery or surveillance across the fitness spectrum. Tests for interaction used CPI scores as a continuous variable but patients also were stratified into tertile groups for descriptive purposes. Hazard ratios were adjusted for age, gender, and aneurysm diameter.
                A total of 714 deaths (95 aneurysm-related) occurred in 8485 person-years (number of patients multiplied by average years of conditional follow-up). The mean (standard deviation [SD]) CPI score was 8.1 (9.9) with similar scores between randomized groups. The tertile groups had mean (SD) scores of -1.8 (3.7) for the 389 fittest patients, 8.8 (3.3) for the 438 moderately fit, 21.4 (6.6) for the 261 least fit with missing scores in 2 patients. The tests for interaction were non-significant for both all-cause (P = .176) and aneurysm-related mortality (.178). However, for the least fit patients a survival advantage was seen in the early surgery group; adjusted hazard ratios 0.73 (95% confidence interval [CI] 0.56-0.96) and 0.46 (95% CI 0.22-0.98) for all-cause and aneurysm-related mortality respectively.
                Early elective surgery did not confer any survival benefit in the fittest patients. On the contrary, the possibility of a survival benefit from early intervention in patients of poor fitness merits further investigation through meta-analysis or validation in other prospective studies.
The results from the four trials to date demonstrate no advantage to early repair (via open or endovascular surgery) for small AAA (4.0 to 5.5 cm) and suggest that 'best care' for these patients favours surveillance. Furthermore, the more recent trials focused on the efficacy of endovascular aneurysm repair and still failed to show benefit. Thus, both open and endovascular repair of small AAAs are not supported by currently available evidence.