Prognostic Significance of Aneurysm Sac Shrinkage After Endovascular Aneurysm Repair

Abstract

Purpose: To investigate whether patients who develop aneurysm sac shrinkage following endovascular aneurysm repair (EVAR) have better outcomes than patients with a stable or increased aneurysm sac. Materials and Methods: The Healthcare Databases Advanced Search interface developed by the National Institute for Health and Care Excellence was used to interrogate MEDLINE and EMBASE. Thesaurus headings were adapted accordingly. Case-control studies were identified comparing outcomes in patients demonstrating aneurysm sac shrinkage after EVAR with those of patients with a stable or expanded aneurysm sac. Pooled estimates of dichotomous outcome data were calculated using the odds ratio (OR) and 95% confidence interval (CI). Meta-analysis of time-to-event data was conducted using the inverse-variance method; the results are reported as a summary hazard ratio (HR) and 95% CI. Summary outcome estimates were calculated using random-effects models. Results: Eight studies were included in quantitative synthesis reporting a total of 17,096 patients (8518 patients with sac shrinkage and 8578 patients without sac shrinkage). The pooled incidence of sac shrinkage at 12 months was 48% (95% CI 40% to 56%). Patients with aneurysm sac shrinkage had a significantly lower hazard of death (HR 0.73, 95% CI 0.60 to 0.87), secondary interventions (HR 0.42, 95% CI 0.29 to 0.62), and late complications (HR 0.37, 95% CI 0.24 to 0.56) than patients with a stable or increased aneurysm sac. Furthermore, their odds of rupture were significantly lower than those in patients without shrinkage (OR 0.09, 95% CI 0.02 to 0.36). Conclusion: Sac regression is correlated to improved survival and a reduced rate of secondary interventions and EVAR-related complications. The prognostic significance of sac regression should be considered in surveillance strategies. Intensified surveillance should be applied in patients who fail to achieve sac regression following EVAR.

Predictors of Abdominal Aortic Aneurysm Shrinkage after Endovascular Repair

“…This research showed a significantly lower all-cause mortality in patients with a shrinking AAA one-year after EVAR, compared to patients with a stable AAA, confirming data of previous studies [ 7 , 8 , 9 ]. In addition, one death of a patient with a stable AAA was EVAR-related, while none of the patients with AAA shrinkage died from this cause.…”

“…A stable or shrinking aneurysm diameter after EVAR has traditionally been considered a treatment success. However, recent studies indicate that patients with AAA shrinkage, at one-year after EVAR, have significantly better long-term outcomes compared to patients with growing AAA, but also to those with stable AAA [ 7 , 8 , 9 , 10 , 11 ]. These outcomes include fewer reinterventions and late complications, less rupture, and a lower all-cause mortality [ 7 , 8 , 9 , 10 , 11 ].…”

“…However, recent studies indicate that patients with AAA shrinkage, at one-year after EVAR, have significantly better long-term outcomes compared to patients with growing AAA, but also to those with stable AAA [ 7 , 8 , 9 , 10 , 11 ]. These outcomes include fewer reinterventions and late complications, less rupture, and a lower all-cause mortality [ 7 , 8 , 9 , 10 , 11 ]. These observations were independent of the occurrence of endoleaks and reinterventions performed [ 7 ].…”

Focused Interventions Aimed at Increasing Sac Shrinkage Rates After Endovascular Aneurysm Repair: Awaiting a Cohesive Analysis

“…We were interested to note this article by Antoniou et al 1 focusing on aneurysm sac shrinkage as a prognosticator for positive outcomes after endovascular aneurysm repair (EVAR), particularly in terms of reduction of rates of reintervention, late aneurysm rupture, other late complications—all considered to be the drawbacks of EVAR—and even death. This would suggest a need to look for particular adjuncts/interventions that might increase the incidence of post-EVAR sac shrinkage, and this aspect has not really been touched upon.…”

Proposed Algorithm for Endovascular Aneurysm Repair Surveillance: A Call for Further Research on Personalized Surveillance

“…We propose a surveillance algorithm that takes account of recommendations from the 2 major vascular society clinical practice guidelines 2,3 and considers the most contemporary evidence, applying a color code, that is, red requiring intervention, yellow requiring further investigations or more intensive surveillance, and green raising no concerns (Figure 2). 4 In this algorithm, after the 30-day computed tomography (CT) scan, we propose different paths based on the CT scan findings indicated by the color code, that is, ultrasound (US) surveillance (± abdominal X-ray) at 12 months if there is no endoleak or there is only a type II endoleak, further investigations with contrast-enhanced US or digital subtraction angiography (and subsequent treatment if necessary) if there is an indeterminate endoleak, or immediate treatment if the CT scan shows a type I or III endoleak. Following the 12-month US scan and in the absence of a malignant or indeterminate endoleak, the mode and frequency of surveillance is determined by the sac behavior and the presence of type II endoleak as follows: The proposed algorithm adopts a pragmatic approach to different modes and imaging frequencies.…”