A systematic review of anatomic predictors of abdominal aortic aneurysm remodeling after endovascular repair

Objective: The long-term outcomes after endovascular abdominal aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) have been inferior to those after open surgical repair with regard to reinterventions and late mortality. AAA sac remodeling after EVAR has been associated with endoleaks, reinterventions, and mortality. Therefore, knowledge of the predictors of AAA sac remodeling could indirectly give insight into the long-term EVAR outcomes. In the present review, we aimed to provide an overview of the evidence for anatomic predictors of positive and negative AAA sac remodeling after EVAR. Methods: A systematic literature review and analysis were conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) and Cochrane guidelines. The PubMed and Scopus databases were searched using terms of AAA sac growth, shrinkage, and remodeling. Eligible studies were identified, and only those studies that had included currently used endografts were included. Results: A total of 19 studies that had reported on a total of 27 anatomic parameters of the aortoiliac anatomy were included. Only 4 parameters had been investigated by more than five studies, 7 parameters were investigated by three to five studies, 7 parameters were investigated by two studies, and 9 parameters were investigated by one study. For the presence of neck thrombus, three of four studies had reported similar results, indicating that the presence of neck thrombus might predict for less AAA sac shrinkage. AAA thrombus, the total AAA volume, the flow-lumen volume, aortic calcification, and the number of hostile neck parameters were only investigated by two to three studies. However, these parameters seemed promising for the prediction of sac remodeling. For hostile neck anatomy, neck length, infrarenal neck angulation, and patency of the inferior mesenteric artery, no significant association with any category of AAA sac remodeling was found. Conclusions: The present review demonstrates neck thrombus, AAA thrombus, number of hostile neck parameters, total AAA volume, AAA flow-lumen volume, and aortic calcification as important anatomic features that are likely to play a role in AAA remodeling after endovascular repair and should be further explored using advanced imaging techniques. We also found that strong, consistent evidence regarding the anatomic predictors of AAA sac remodeling after EVAR is lacking. Therefore, further research with large patient groups for a broad range of predictors of AAA sac change after EVAR is needed to complement the current gap in the evidence

Outcome and quality of life after endovascular abdominal aortic aneurysm repair in octogenarians

ObjectiveThis study determined outcome and quality of life (QOL) in octogenarians, compared with patients aged <80 years, 1 year after endovascular aortic aneurysm repair (EVAR).MethodsFrom March 2009 until April 2011, 1263 patients in the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) registry with an abdominal aortic aneurysm were treated with EVAR using the Endurant endograft (Medtronic Cardiovascular, Santa Rosa, Calif). The patients were grouped according to those aged ≥80 years (290 [22.9%]) and those aged <80 years (973 [77.1%]) at the time of the procedure. QOL was assessed using composite EuroQoL 5-Dimensions Questionnaire (EQ-5D) index scores. Baseline, perioperative, and follow-up data were analyzed at 1 year.ResultsOctogenarians had poorer anatomic characteristics. The technical success rate was almost 99% for both cohorts, with no deaths. The duration of the implant procedure was significantly longer in the elderly patients (P = .002), with significant differences in overall (P < .001) and postprocedure (P < .001) hospital stays in favor of the younger group. At 1 year, there was a significant difference in all-cause mortality (P = .002) and in the number of major adverse events (P = .003), including secondary rupture (P = .01), to the detriment of octogenarians. There were no significant differences in conversion to open surgery or in overall secondary endovascular procedures. The octogenarians scored lower in their overall health care perception (P < .001) but with no significant difference in the EQ-5D index. Compared with the group aged <80 years, they had still not completely recovered their QOL after 1 year (P = .01).ConclusionsOctogenarians are more difficult to treat by EVAR than younger patients due to poorer anatomic suitability and a higher incidence of complications. Recovery of QOL in octogenarians takes longer (>12 months) than expected

Survival After Endovascular Aneurysm Sealing Compared With Endovascular Aneurysm Repair

Introduction Endovascular aneurysm sealing (EVAS) is a sac-filling device with a blunted systemic inflammatory response compared to conventional endovascular aneurysm repair (EVAR), with a suggested impact on all-cause mortality. This study compares mortality after both EVAS and EVAR. Materials and Methods This is a retrospective observational study including data from 2 centres, with ethical approval. Elective procedures on asymptomatic infrarenal aneurysms performed between January 2011 until April 2018 were enrolled. Laboratory values (serum creatinine, haemoglobin, white blood cell count, platelet count) were measured pre- and postoperatively and at 1 and 2 years, respectively. Mortality and cause of death were recorded during follow-up. Results A total of 564 patients were included (225 EVAS, 369 EVAR), after propensity score matching there were 207 patients in both groups. Baseline characteristics were similar, except for larger neck angulation and more pulmonary disease in the EVAR group. The median follow-up time was 49 (EVAS) and 44 (EVAR) months. No significant differences regarding creatinine and haemoglobin were observed. Preoperative white blood cell count was higher in the EVAR group (p=0.011), without significant differences during follow-up. Median platelet count was lower in the EVAR group preoperatively (p=0.001), but was significantly higher at 1 year follow-up (p=0.003). There were 43 deaths within the EVAS group (20.8%) and 52 within the EVAR group (25.1%) (p=0.293). Of these, 4 were aneurysm related (EVAS n=3, EVAR n=1; p=0.222) and 14 cardiovascular (EVAS n=6, EVAR n=8, p=0.845). For the EVAS cohort, survival was 95.5% at 1 year and 74.9% at 5 years. For the EVAR cohort, this was 93.3% at 1 year and 75.5% at 5 years. No significant differences were observed in causes of death. Conclusion This study showed comparable survival rates through 5 years between EVAS and EVAR with a tendency toward higher inflammatory response in the EVAR patients through the first 2 years

Haemodynamics in Different Flow Lumen Configurations of Customised Aortic Repair for Infrarenal Aortic Aneurysms

Objective: Customised aortic repair (CAR) is a new and minimally invasive technique for the endovascular treatment of abdominal aortic aneurysms (AAAs). The aneurysm is completely sealed with a non-contained, non-cross linked polymer, while a new flow lumen is created with balloons. For CAR, the haemodynamically most favourable balloon and flow lumen configuration has not been established before; therefore, four flow parameters were assessed in an in vitro model. Methods: Three in vitro balloon configurations were implanted in an in vitro AAA model; a configuration with crossing balloons (CC) and two parallel configurations (PC1 and PC2). These three models were consecutively placed in a flow system that mimics physiological flow conditions. Laser particle imaging velocimetry (PIV) was used to resolve spatial and temporal flow patterns during the cardiac cycle. In house built algorithms were used to analyse the PIV data for the computing of (i) flow velocity; (ii) vorticity; (iii) wall shear stress (WSS); and (iv) time averaged wall shear stress (TAWSS). Results: Suprarenal flow patterns were similar in all models. The CC showed a higher infrarenal velocity than PC1 and PC2 (38 cm/s vs. 23 cm/s vs. 23 cm/s), and a higher vorticity at the crossing of the lumens (CC: 337/s; PC1 127/s; PC2: 112/s). The lowest vorticity was observed in PC2, especially in the infrarenal neck (CC: 200/s; PC1 164/s; PC2: 98/s). Although WSS and TAWSS varied between configurations, values were the within non-pathological range. Conclusion: The flow lumens created by three balloon configurations used in an in vitro model of CAR have been studied, and resulted in different haemodynamics. The differences in velocity and lower vorticity, especially at the crossing section of the two balloons, showed that PC2 has favourable haemodynamics compared with the CC and PC1. Future research will be focused on the clinical applicability of CAR based on the PC2 design

Incidence and predictive factors for endograft limb patency of the fenestrated Anaconda endograft used for complex endovascular aneurysm repair

Objective: In the present study, we have described the incidence, risk factors, and outcomes of treatment of limb occlusion for patients who had undergone treatment of complex thoracoabdominal aortic aneurysms with the fenestrated Anaconda endograft (Terumo Aortic, Inchinnan, UK). Methods: Between June 2010 and May 2018, 335 patients had undergone elective fenestrated aortic aneurysm repair at 11 participating centers using the fenestrated Anaconda endograft with a median follow-up of 14.3 months (interquartile range, 27.4 months). The primary outcome measure was freedom from limb occlusion. The secondary outcome measures were freedom from limb-related reintervention, secondary patency, and the risk factors associated with limb occlusion. Results: Of the 335 patients, 30 (9.0%) had presented with limb occlusion during follow-up with a freedom from limb occlusion rate of 98.5%, 91.2%, and 81.7% at 30 days and 1 and 5 years, respectively. In 87% of the cases, no obvious cause for limb occlusion was documented. Primary occlusion had occurred within 30 days in 36.7% and within 1 year in 80.0%. Of the 30 patients, 23 (77%) had undergone an occlusion-related reintervention and 7 (23.3%) had been treated conservatively. The freedom from limb occlusion-related reintervention at 30 days and 1 and 5 years was 97.8%, 93.2%, and 88.6%, respectively. Secondary patency was 91.3% after 1 month and 86.2% after 1 and 5 years. Female sex (odds ratio [OR], 3.27; 95% confidence interval [CI], 1.28-8.34; P = .01) was a statistically significant predictor for limb occlusion. A greater proportion of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% vs 50%: OR, 0.08; 95% CI, 0.020.38; P = .00), as did iliac angulation (OR, 0.99; 95% CI, 0.98-1.00; P = .04). Conclusions: Limb occlusion remains a significant impediment of endograft durability for patients treated with the fenestrated Anaconda endograft, especially for female patients. In contrast, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified