Search

Imaging surveillance after endovascular aortic aneurysm repair (EVAR) is critical. In this study we analyzed compliance with imaging surveillance after EVAR and its effect on clinical outcomes.Retrospective analysis of prospectively collected data of 565 EVAR patients (August 2001-November 2013), who were followed using duplex ultrasound and/or computed tomography angiography. Patients were considered noncompliant (NC) if they did not have any follow-up imaging for 2 years and/or missed their first post-EVAR imaging over 6 months. A Kaplan-Meier analysis was used to compare compliance rates in EVAR patients with hostile neck (HN) vs favorable neck (FN) anatomy (according to instructions for use). A multivariate analysis was also done to correlate compliance and comorbidities.Forty-three percent were compliant (7% had no follow-up imaging) and 57% were NC. The mean follow-up for compliant patients was 25.4 months (0-119 months) vs 31.4 months for NC (0-140 months). The mean number of imaging was 3.5 for compliant vs 2.6 for NC (P.0001). Sixty-four percent were NC for HN patients vs 50% for FN patients (P = .0007). The rates of compliance at 1, 2, 3, 4, and 5 years for all patients were 78%, 63%, 55%, 45%, and 32%; and 84%, 68%, 61%, 54%, and 40% for FN patients; and 73%, 57%, 48%, 37%, and 25% for HN patients (P = .009). The NC rate for patients with late endoleak and/or sac expansion was 58% vs 54% for patients with no endoleak (P = .51). The NC rate for patients with late reintervention was 70% vs 53% for patients with no reintervention (P = .1254). Univariate and multivariate analyses showed that patients with peripheral arterial disease had an odds ratio of 1.9 (P = .0331), patients with carotid disease had an odds ratio of 2 (P = .0305), and HN patients had an odds ratio of 1.8 (P = .0007) for NC. Age and residential locations were not factors in compliance.Overall, compliance of imaging surveillance after EVAR was low, particularly in HN EVAR patients, and additional studies are needed to determine if strict post-EVAR surveillance is necessary, and its effect on long-term clinical outcome.

Background Validation of subclavian duplex ultrasound velocity criteria (SDUS VC) to grade the severity of subclavian artery stenosis has not been established or systematically studied. Currently, there is a paucity of published literature and lack of practitioner consensus for how subclavian duplex velocity findings should be interpreted in patients with subclavian artery stenosis. Objective The objective of the present study was to validate SDUS measurements using subclavian conventional or computed tomography angiogram (subclavian angiogram [SA])-derived measurements. Secondary objectives included measuring the correlation between SDUS peak systolic velocities and SA measurements, and to determine the optimal cutoff value for predicting significant stenosis (>70%). Methods This is a retrospective review of all patients with suspected subclavian artery stenosis and a convenience sample of carotid artery patients who underwent SDUS and SA from May 1999 to July 2013. SA reference vessel and intralesion minimal lumen diameters were measured and compared with SDUS velocities obtained within 3 months of the imaging study. Percent stenosis was calculated using the North American Symptomatic Carotid Endarterectomy Trial method for detecting stenosis in a sufficiently large cohort. Receiver operating characteristic curves was generated for SDUS VC to predict >70% stenosis. Velocity cutoff points were determined with equal weighting of sensitivity and specificity. Results We examined 268 arteries for 177 patients. The majority of the arteries were for female patients (52.5%) with a mean age of 66.7 ± 11.1 years. Twenty-three arteries had retrograde vertebral artery flow and excluded from further analysis. For the remaining 245 arteries, the average peak systolic velocity was 212.6 ± 110.7 cm/s, with a range of 45-626 cm/s. Average stenosis was 25.8% ± 28.2%, with a range of 0% to 100%. Following receiver operating characteristic analysis, we found a cutoff value of >240 cm/s to be most predictive of >70%. Area under the curve was 0.94 with 95% confidence intervals of 0.91 to 0.97. The sensitivity and specificity for predicting >70% stenosis was 90.9 and 82.5%, respectively. Conclusions In patients with known or suspected disease involving the great vessels, a subclavian artery flow velocity exceeding 240 cm/s seems to be predictive of significant subclavian stenosis. Thus, we propose new SDUS VC, for predicting subclavian artery stenosis. However, because of the use of a convenience sample, it is possible that the current proposed cutoff point might need to be adjusted for other populations.