Infrarenal Aortic Aneurysm Repair Research Articles

Long-term Outcomes of Elective Endovascular Repair of Asymptomatic Infrarenal Aortic Aneurysms with the Zenith Stentgraft

Long-term Outcomes of Elective Endovascular Repair of Asymptomatic Infrarenal Aortic Aneurysms with the Zenith Stentgraft

Chronology and Outcomes of Secondary Procedures After Endovascular Repair of Infrarenal Abdominal Aortic Aneurysms

Introduction: Endovascular Repair of Abdominal Aortic Aneurysms (EVAR) is associated with a significant rate of mid- and long-term complications that might require reinterventions in order to maintain clinical success. This justifies the strict continuous monitoring of EVAR patients over the long run. Questions as to whether one could ease the surveillance policy after a certain amount of time are of interest but remain largely unanswered. The goal of this study was to assess the timing and the morbidity-mortality associated with secondary procedures during the follow-up of EVAR patients Methods: Between January 2010 and December 2018, this study recruited all consecutive patients who underwent elective EVAR in a single center. Follow-up ended on March 23, 2019. Data were collected in an electronic database and analyzed retrospectively. The main outcome measures were the incidence rate of secondary procedures and their time of occurrence. Further analysis included the incidence rate of aneurysm-related complications, their occurrence time during follow-up, the 30-day mortality associated with the secondary procedures and the 5-yr overall survival rate. P-value < 0.05 was considered statistically significant. Results: Two hundred and fifty EVAR patients [94% male; median age: 77years (IQR: 69-82)] were included and contributed a total of 1078 person-years of follow-up time. The 30-day mortality after the index EVAR procedure was 2.4% (6/250), leaving 244 patients for subsequent monitoring. Median follow-up was 63months (IQR: 27-90). The incidence rate of aneurysm-related complications was 4.73 cases per 100 person-years. Most common complications included type-II endoleaks (25 cases), stent-graft limb thrombosis (12 cases), type-I endoleak (5 cases), type-III endoleak (2cases) and stent-graft infection (2 cases). A secondary procedure was mandatory in 32 patients yielding to an incidence rate of 3 cases per 100 person-years. Median time elapsed between EVAR and the first reintervention was 5months with 16mo and 35mo being the 75th and 90thpercentile respectively. There were 3 conversions to open repair, 15 miscellaneous surgical procedures, while 14 patients required 24 various endovascular reinterventions. Freedom from secondary procedure was 92%, 87%, and 86% at 1-yr, 3-yr and 5-yr respectively. The 30-day mortality associated with the secondary procedure was 3% (1/32). At 5-year, the actuarial survival rate was 89% in patients who underwent a secondary procedure vs. 88% in patients who did not (P=0.79). Conclusion: In this study, secondary procedures after EVAR were associated with low morbidity-mortality and tended to occur within the first 3-yr of follow-up. A small subset of patients required repeated secondary procedures beyond 3 years to maintain long-term clinical success. This suggests that long-term strict monitoring might be indicated only in this subset of patients. Disclosure: Nothing to disclose

The Effect of Compliance Versus Non-compliance to Standard Imaging After Endovascular Aneurysm Repair on Re-intervention Rate and Mortality: A Systematic Review and Meta-analysis

Introduction - Yearly imaging surveillance is recommended for patients who have undergone endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysms to detect complications requiring reintervention. However, this is also a burden to patients and the healthcare system. It is yet unknown whether yearly imaging surveillance actually detects additional complications requiring reintervention and decreases the mortality rate. We aimed to study the effect of imaging surveillance after EVAR on reintervention rate and mortality. Also, what percentage of complications requiring reinterventions is detected via imaging surveillance compared to patients presenting with symptoms. Methods - Systematic review of cohort studies that compared complications in patients compliant to imaging surveillance with non-compliant patients. Two review authors independently performed the inclusions, quality assessment and data extraction. Risk differences as to reintervention and mortality rates between compliant and non-compliant patients were meta-analysed. Results were presented as absolute risk differences (ARD) with 95% confidence intervals (CI). A Mantel&Haenszel fixed effect model was used, if statistical heterogeneity was limited, i.e. having an I2 <50,. A Dersimonian&Laird random effects model was used, if statistical heterogeneity was present, i.e. an I2 >50%, Results - We included 11 relevant publications. Studies differed in imaging surveillance protocols and definitions for compliance subgroup. Pooled absolute risk difference (ARD) for reintervention rate was 4% (95%CI[1 to 7%]) in favour of imperfect/non-compliance (NNT 25; 95%CI[14 to100]), while mortality showed a non-significant ARD of 12% (95%CI[-2 to 26%]) in favour of imperfect/non-compliance. Two studies reported that complications requiring reintervention detected via imaging surveillance ranged between 41% and 53%, compared to patients presenting with symptoms. Conclusion - Patients who are compliant to imaging surveillance undergo more reinterventions than those who are imperfectly or non-compliant. However, this does not necessarily protect against mortality. This suggests that the recommended yearly imaging surveillance may not be beneficial for all EVAR-patients.

Fenestrated and Branched Endografting After Previous Open Infra-renal Aortic Aneurysm Repair

Introduction - Proximal para-anastomotic aneurysms, or aneurysmal degenerations of the native aorta above a previous infra-renal aortic open repair (P-AAAs), are not rare challenging scenarios. The aim of this study was to report the early and mid-term outcomes following endovascular repair of P-AAAs with fenestrated and branched endografts (FB-EVAR) Methods - From 2006 to 2017, we prospectively collected and retrospectively analyzed pre, intra and postoperative data of patients undergoing FB-EVAR for P-AAAs at two European vascular surgery units. Early outcomes were: technical success (target visceral vessels cannulation and stenting, absence of Type I-III endoleak, iliac limb occlusion and 24-h mortality), spinal cord ischemia (SCI), and 30-day mortality. Mid-term outcomes were: survival, target visceral vessels (TVV) patency, and freedom from re-interventions. Fisher’s exact test, Kaplan Mayer and Log rank were used for the statistical analysis Results - During the study period, 108 patients (M:94%; age:71±4years; ASA 3-4:74%>26%) were enrolled. The previous aortic OR was a tubular aorto-aortic 63(58%), a bifurcated aorto bi-iliac 37(34%) or an aorto bi-femoral 8(8%) bypass. The OR was performed 10±2years prior to the FB-EVAR. A previous TEVAR had also been performed in 7 patients (6%). The aortic lesions at the time of FB-EVAR was a type I-III 69(64%) or type IV 39(36%) thoracoabdominal aneurysm according to the Crawford’s classification. The mean aneurysm diameter was 64±6mm. Overall, 390 TVVs (3.6±1 TVV/case) were perfused by endograft fenestrations (63;58%), branches (26;24%) or both fenestrations and branches (19;18%). Tubular, tri-modular or aorto-monoiliac implants were planned in 68 (63%), 38 (35%) and 2 (2%) patients, respectively. Proximal TEVAR, carotid-subclavian bypass and iliac branch devices were planned adjunctive procedures in 41 (38%), 5 (5%) and 3 (3%) cases, respectively. Technical success was 93%. Technical failures included 5 TVV-loss (celiac trunk:1; renal arteries:4) and 3 deaths within 24 hours (cardiac aetiology). Post-operative SCI was diagnosed in 7 patients (7%), including 4 (4%) permanent. Type I-III TAAAs (p .04) and endograft incorporating both fenestrations and branches (p .04) were associated with SCI. Cardiac and pulmonary morbidity was 9% and 10%, respectively. Post-operative renal failure (GFR reduction >30% of baseline) was diagnosed in 22 patients (20%). Bowel ischemia was depicted in 3 (3%) patients. The 30-day mortality was 4%. Preoperative chronic renal failure (p .03), post-operative cardiac morbidity (p .04), and bowel ischemia (p .003) were associated with 30-day mortality. The mean follow-up was 38±18 months. Survival at 1, 3 and 5 years was 82%, 64% and 54%, respectively. There was no late aneurysm-related mortality. Survival during follow-up was significantly impacted by pre-operative chronic renal failure (p .005), post-operative cardiac morbidity (p .04), and SCI (p .04). Target visceral patency at 1, 3 and 5 years was 93%, 91% and 91%, respectively. New onset of hemodialysis was required in 4 patients (4%). Aneurysm enlargement (>5mm) was detected in 6 (5.5%) cases. Freedom from re-interventions at 1, 3 and 5 years was 89%, 77% and 74%, respectively Conclusion - Endovascular treatment of aortic aneurysmal evolution above a prior open AAA repair with FB-EVAR is safe and effective. If those promising results are confirmed during late follow-up, FB-EVAR should be considered as a therapeutic option, especially in high-risk patients

Kidney Failure After Occlusion of Accessory Renal Arteries in Endovascular Abdominal Aneurysm Repair.

To evaluate the incidence of acute renal failure and chronic kidney disease due to occlusion of accessory renal arteries during endovascular aneurysm repair of infrarenal abdominal aortic aneurysm. We retrospectively reviewed the course of 181 patients (mean age, 71, SD ± 9 years) who underwent EVAR of infrarenal abdominal aortic aneurysm. The renal vessel anatomy was analyzed in all pre- and postoperative CT scans. Diameter and origin of accessory renal arteries were evaluated. Renal function was determined by pre- and postoperative serum creatinine and eGFR levels. Long-term follow-up (>3months) of patients was available in 121 cases (66.9%). Acute kidney injury and chronic kidney failure were defined according to guidelines of "Kidney Disease: Improving Global Outcomes" (KDIGO). In 65 of 181 patients (33.9%), 82 accessory renal arteries were identified preoperatively. In 19 of 181 patients (10.5%), one or more accessory renal arteries were covered and subsequently occluded by the implanted stent-graft device. Neither acute kidney injury (10.3% vs 12.5%; p = .785) nor chronic kidney disease (10.7% vs 15.38%; p = .452) was detected significantly more often in patients with covered accessory renal artery. The only significant predictor of acute kidney injury was the preoperative serum creatinine level (1.12mg/dl vs. 0.98mg/dl; p = .03). Significant predictors for chronic kidney disease were preoperative serum creatinine, eGFR, and impaired renal function (p < .001). Coverage of accessory renal artery due to stent-graft does not lead either to temporary acute kidney injury after endovascular aneurysm repair or to chronic kidney disease. Level II b.

The patency of internal iliac arteries and its role in the development of buttock claudication syndrome in the remote period after open infrarenal aortic aneurysm repair

The OBJECTIVE was to study the patency of the internal iliac artery and its effect to gluteus muscles blood supply and frequency of buttock claudication occurrence in the remote period after open infrarenal aortic aneurysm repair. MATERIAL AND METHODS. Examination of 37 patients after open infrarenal aortic aneurysm repair included collection of complaints, anamnesis, making CT scan with contrast and pelvic perfusion tomography. These methods allowed to assess the patency of the prosthesis and iliac arteries, calculate average blood flow rate in buttock muscles and frequency of buttock claudication occurrence depending on the lesion of the internal iliac arteries. RESULTS. Five-year patency of the internal iliac artery was 93 %. In case of passable internal iliac artery, the average blood flow rate in the ipsilateral buttock muscles was authentically higher than the same indicator in groups with stenotic or occlusive lesion of the internal iliac artery and its branches. In case of the disturbed internal iliac artery patency, the frequency of occurrence of the buttock claudication in the same side reached 50 %. CONCLUSION. High five-year internal iliac artery patency after open infrarenal aortic aneurysm repair attested the necessity of preservation the main blood flow in these arteries during the open infrarenal aortic aneurysm repair for the purpose of buttock claudication prevention. The CT scan allowed to evaluate the internal iliac artery patency and the average blood flow rate in the buttock muscles through perfusion tomography method which was necessary for differential diagnosis of the buttock claudication syndrome.

Preservation of pelvic perfusion with iliac branch devices does not decrease ischemic colitis compared with hypogastric embolization in endovascular abdominal aortic aneurysm repair

ObjectiveIschemic colitis is a rare but devastating complication of endovascular repair of infrarenal abdominal aortic aneurysms. Although it is rare (0.9%) in standard endovascular aneurysm repair (EVAR), the incidence increases to 2% to 3% in EVAR with hypogastric artery embolization (HAE). This study investigated whether preservation of pelvic perfusion with iliac branch devices (IBDs) decreases the incidence of ischemic colitis. MethodsWe used the targeted EVAR module in the American College of Surgeons National Surgical Quality Improvement Program database to identify patients undergoing EVAR of infrarenal abdominal aortic aneurysm from 2012 to 2017. The cohort was further stratified into average-risk and high-risk groups. Average-risk patients were those who underwent elective repair for sizes of the aneurysms, whereas high-risk patients were repaired emergently for indications other than asymptomatic aneurysms. Within these groups, we examined the 30-day outcomes of standard EVARs, EVAR with HAE, and EVAR with IBDs. The primary outcome was the incidence of ischemic colitis. Secondary outcomes included mortality, major organ dysfunction, thromboembolism, length of stay, and return to the operating room. The χ2 test, Fisher exact test, Kruskal-Wallis test, and multivariate regression models were used for data analysis. ResultsThere were 11,137 patients who had infrarenal EVAR identified. We designated this the all-risk cohort, which included 9263 EVAR, 531 EVAR-HAE, and 1343 EVAR-IBD procedures. These were further stratified into 9016 cases with average-risk patients and 2121 cases with high-risk patients. In the average-risk group, 7482 had EVAR, 411 had EVAR-HAE, and 1123 had EVAR-IBD. In the high-risk group, 1781 had EVAR, 120 had EVAR-HAE, and 220 had EVAR-IBD. There was no significant difference in 30-day outcomes (including ischemic colitis) between EVAR, EVAR-HAE, and EVAR-IBD in the all-risk and high-risk groups. In the average-risk cohort, EVAR-HAE was associated with a higher mortality rate than EVAR (2.2% vs 1.0%; adjusted odds ratio, 2.58; P = .01). Although EVAR-IBD was not superior to EVAR-HAE in 30-day mortality, major organ dysfunction, or ischemic colitis in this average-risk cohort, EVAR-IBD exhibited a trend toward lower mortality compared with EVAR-HAE in this cohort, but it was not statistically significant (1.0% vs 2.2%; adjusted odds ratio, 0.42; P = .07). ConclusionsIschemic colitis is a rare complication of EVAR. HAE does not appear to increase the risk of ischemic colitis, and preservation of pelvic perfusion with IBDs does not decrease its incidence. Although HAE is associated with significantly higher mortality than standard EVAR in average-risk patients, the preservation of pelvic perfusion with IBDs does not appear to improve mortality over HAE.

Endovascular Aneurysm Repair May Provide a Survival Advantage in Patients Deemed Physiologically Ineligible for Open Abdominal Aortic Aneurysm Repair

Cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capacity and fitness. It can be used to guide decision making prior to major vascular surgery. The EVAR-2 trial suggested that endovascular aneurysm repair (EVAR) in patients unfit for open repair failed to provide a significant survival advantage over nonsurgical management. The aim of this study is to assess contemporary survival differences between patients with poor CPET measures who underwent EVAR or were not offered surgical intervention. A prospectively maintained database of CPET results of patients considered for elective infrarenal aortic aneurysm repair were interrogated. Anaerobic threshold (AT) of <11mL/min/kg was used to indicate poor physical fitness. Hospital electronic records were then reviewed for perioperative, reintervention, and long-term outcomes. Between November 2007 and October 2017, 532 aortic aneurysm repairs were undertaken, of which 376 underwent preoperative CPET. Seventy patients were identified as having an AT <11mL/min/kg. Thirty-seven patients underwent EVAR and 33 were managed nonsurgically. All-cause survival at 1, 3, and 5years for those patients who underwent EVAR was 97%, 92%, and 81%, respectively. For those not offered surgical intervention survival at the same points was 72%, 48%, and 24% [hazard ratio, HR=5.13 (1.67-15.82), P=0.004]. Aneurysm-specific survival at 1, 3, and 5years for those patients who underwent EVAR was 97%, 94%, and 94%, respectively. Survival at the same time points for those not offered surgical intervention was 90%, 69%, and 39%, respectively [HR=7.48 (1.37-40.82), P=0.02]. In this small, retrospective, single-center, nonrandomized cohort, EVAR may provide a survival advantage in patients with poor physical fitness identified via CPET. Randomized studies with current generation EVAR are required to validate the results shown here.

IP053. White Blood Cell Count Independently Predicts Adverse Events Following Endovascular Aneurysm Repair for Intact Infrarenal Abdominal Aortic Aneurysm

IP053. White Blood Cell Count Independently Predicts Adverse Events Following Endovascular Aneurysm Repair for Intact Infrarenal Abdominal Aortic Aneurysm

SS03. Results of Fenestrated and Branched Endovascular Aortic Aneurysm Repair After Failed Infrarenal Endovascular Aortic Aneurysm Repair

Failure of infrarenal endovascular aortic aneurysm repair (EVAR) owing to loss of proximal seal is increasingly common. Open surgical conversion is challenging and associated with significant morbidity/mortality. The aim of this study was to evaluate the use of fenestrated/branched endovascular aortic repair (F/BEVAR) for the treatment of patients with prior EVAR failure. Consecutive patients enrolled in six, prospective, nonrandomized, physician-sponsored investigational device exemption studies evaluating F/BEVAR between 2012 and 2018, were included in this study. The cohort was stratified according to whether the F/BEVAR procedure was performed after EVAR failure. Demographics, operative details, perioperative complications, and length of stay were compared between groups. Patient survival, type I or type III endoleak, target artery patency, and reintervention rates were calculated using Kaplan-Meier method and compared between groups. A total of 893 patients underwent F/BEVAR; 161 (18%) were treated after failed EVAR and 732 (82%) were treated without prior EVAR. Patients with failed EVAR were more often men (84% vs 66%; P < .01) with larger aneurysms (6.9 cm vs 6.4 cm; P < .01). There were no differences in aneurysm extent (P = .20) between the groups: 19% juxtarenal, 9.2% suprarenal, and 72% thoracoabdominal. The average number of targeted arteries per patient was 3.6 in both groups. The procedural technical success (99% vs 97%; P = .15) did not differ between groups, but radiation dose (4753 mGy vs 2924 mGy; P = .02), dose area product (154,572 mGy cm2 vs 82,842 mGy cm2; P < .01), and operative time (5.2 hours vs 4.6 hours; P < .01), were significantly higher in the failed EVAR group. Median intensive care length of stay (2.9 days) and total length of stay (6.3 days) did not differ between groups. The 30-day mortality rate (failed EVAR, 2.5%; no EVAR, 1.1%; P = .25) and 30-day major adverse event rate (Fig 1) did not differ between groups. Kaplan-Meier estimates of freedom from death (88.3% vs 92.5%; P = .10; Fig 2), type I or type III endoleak (91.9% vs 92.5%; P = .65), target artery occlusion (97.3% vs 97.0%; P = .91), and reintervention at 1 year (84.7% vs 88.7%; P = .10) did not differ between the failed EVAR and no EVAR group, respectively. In this multicenter study, F/BEVAR was safe and effective in patients with prior failed EVAR, with nearly identical outcomes as compared with patients without prior EVAR. However, differences in procedural metrics indicate higher level of technical challenge when performing F/BEVAR in patients with prior failed EVAR.Fig 2Kaplan-Meier estimates of freedom from death. EVAR, Endovascular aortic aneurysm repair.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Long-term results after standard endovascular aneurysm repair with the Endurant and Excluder stent grafts

ObjectiveMany endografts are currently available for standard endovascular repair of infrarenal abdominal aortic aneurysms. Comparison of long-term outcomes between devices might aid in this decision process, but comparative data are scarce. The purpose of this study was to report long-term clinical outcomes of two commercially available endoprosthesis, the Endurant (Medtronic Vascular, Inc, Minneapolis, Minn) and the Excluder (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts. MethodsPatients undergoing standard endovascular repair from July 2004 to December 2011 in a single institution with the Endurant or the Low-Porosity Excluder endografts were eligible. Only patients treated for intact degenerative abdominal infrarenal aneurysms were included. All measurements were performed on center-lumen line reconstructions obtained on dedicated software. The primary end point was primary clinical success, defined as clinical success without the need for an additional or secondary surgical or endovascular procedure. Neck-related events (a composite of type IA endoleak, neck-related secondary intervention, or migration of >5 mm), neck morphology changes, renal function, and overall survival were secondary end points. ResultsThe study included 277 patients (156 Endurants; 121 Excluders). The median follow-up was 5.8 years (range, 0.1-12.4 years) and did not differ between groups (P = .18). Patients treated with the Endurant stent graft had wider (neck diameter of >28 mm, 27.3% vs 1.7% [P < .001]; neck diameter of 27 mm, [interquartile range (IQR), 24-29 mm] for Endurant and 24 mm [IQR, 22-25 mm] for Excluder; P < .001) and more angulated necks (β-angle of >60°, 26.7% vs 12.5%; P = .004). Oversizing was greater in the Endurant group (16% [IQR, 12%-22%] vs 13% [IQR, 8%-17%], respectively; P < .001). Patients were treated outside device instructions for use regarding proximal neck: 16.7% in the Endurant and 17.3% in the Excluder group (P = .720). The 7-year primary clinical success was 54.7% for the Endurant and 58.1% for the Excluder groups (P = .53). Freedom from neck-related events at 7 years was 76.7% for the Endurant and 78.8% for Excluder group (P = .94). The Endurant stent graft (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.3-5.8; P = .009) was an independent predictor of significant renal function decline. Neck dilatation was greater in Endurant-implanted patients (13% [95% CI, 2%-22%] vs 4% [95% CI, 0%-10%]; P < .001). Overall survival at 7 years was 61.4% in the Endurant and 50.3% (n = 50; standard error, 0.047) in the Excluder group (P = .39). ConclusionsThis study reveals that durable and sustainable results can be obtained with either of these late generation devices. This finding suggests that careful planning and a tailored device selection taking into account the patient's anatomy are more relevant determinants than the graft model itself to obtain clinical success. The Endurant endoprosthesis seems to be associated with a higher rate of neck dilatation and faster decrease in the estimated glomerular filtration rate, but further studies with longer follow-up are necessary to determine the clinical relevance of these findings.

Large Diameter (≥29 mm) Proximal Aortic Necks Are Associated with Increased Complication Rates after Endovascular Repair for Abdominal Aortic Aneurysm

The aim of this study is to investigate the impact of proximal aortic diameter on outcome after endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs). This is a case-control (1:1) retrospective analysis of prospectively collected data on 732 AAA patients treated with EVAR in 2 university centers. Patients with an infrarenal neck diameter of 29-32mm (wide neck, WN group) were compared with patients with a neck diameter of 26-28.9mm (control group) matched for age, gender, and maximum aneurysmal sac diameter. Any patients treated outside the instructions for use of each endograft or with no adequate follow-up were excluded. The primary end point was any neck-related adverse event (a composite of type Ia endoleak, neck-related secondary intervention, and endograft migration) during follow-up. Sixty-four patients with a proximal neck diameter of 29-32mm (WN group) were compared with a matched control group of 64 patients with a neck diameter of 26-28.9mm (control group). Oversizing was significantly higher in the study group (17.9% vs. 15.5%, P=0.001). Overall median available follow-up was 24months (range 12-84) (WN group 24months vs. control group 18.5months, P=0.943). Primary end point was recorded in 8 patients (12.5%) of the WN group and in 1 patient (1.6%) of the control group. Freedom from the primary end point at 36months (standard error <10%) was 87.3% for the study versus 98.4% for the control group (log rank=4.66, P=0.03). On multiple regression analysis, the presence of a proximal aortic neck >29mm was the only independent risk factor for neck-related adverse events (odds ratio 7.4, 95% confidence interval 1.2-47.1). EVAR in the presence of a wide proximal aortic neck is likely to be associated with higher adverse neck-related event rates and thus, in such cases closer follow-up may be required.

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

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 invitro model. Three invitro balloon configurations were implanted in an invitro 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). Suprarenal flow patterns were similar in all models. The CC showed a higher infrarenal velocity than PC1 and PC2 (38cm/s vs. 23cm/s vs. 23cm/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 in the within non-pathological range. The flow lumens created by three balloon configurations used in an invitro 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.

Endovascular aneurysm repair in patients with a wide proximal aortic neck: a systematic review and meta-analysis of comparative studies.

The aim was to investigate the impact of wide proximal aortic diameter on outcome after standard endovascular repair (sEVAR) of infrarenal abdominal aortic aneurysms. A systematic search of the literature was undertaken using the PUBMED, EMBASE, and Cochrane databases for articles comparing outcome after sEVAR in patients with large versus small diameter aortic neck. The prognostic factor of interest was large diameter proximal aortic neck and the results were reported as odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI). A time-to-event data meta-analysis for late outcomes was performed using the inverse-variance method and reported the results as summary hazard ratio (HR) and 95% CI. We identified 6 observational studies reporting on a total of 6602 patients (1616 with large and 4986 with small diameter neck). Patients with large proximal aortic neck were older (MD 0.87, 95% CI: 0.35-1.39; P=0.001). The prevalence of male gender (OR=1.63, 95% CI: 1.34-1.98; P<0.001), coronary artery disease (OR=1.20, 95% CI: 1.06-1.36; P=0.004), chronic obstructive pulmonary disease (OR=1.18, 95% CI: 1.03-1.36; P=0.02) and chronic kidney disease (OR=1.43, 95% CI: 1.23-1.66; P<0.001) was higher in the wide neck group. Patients with large diameter proximal neck had shorter proximal neck (MD=-1.91, 95% CI: -2.04 to -1.77; P<0.001) and a larger aneurysm diameter compared to those with small diameter neck (MD=3.40, 95% CI: 2.71-4.10; P<0.001). Patients with small diameter proximal neck had significantly higher freedom from aneurysm-related reintervention (HR=2.06, 95% CI: 1.23-3.45; P=0.006), freedom from type Ia endoleak (HR=6.69, 95% CI: 4.39-10.20; P<0.001), freedom from sac expansion (HR=10.07, 95% CI: 1.80-56.53; P=0.009), freedom from aneurysm rupture (HR 5.10, 95% CI: 1.40-18.58; P=0.01), and survival (HR=1.55, 95% CI: 1.08-2.24; P=0.02). Patients with a wide proximal aortic neck undergoing standard EVAR were found to have worse outcome, as indicated by a lower freedom from aneurysm-related reintervention, type Ia endoleak, sac expansion and aneurysm rupture, and a higher overall survival. This anatomic characteristic should be considered in decision making. In such patients, closer imaging surveillance after EVAR in the long term may be required to identify early and treat timely the complications.

Outcomes of endovascular treatment of endoleak type Ia after EVAR: a systematic review of the literature

Endovascular repair of infra-renal aortic aneurysm (EVAR) has become treatment of choice. However, individuals undergoing EVAR have a high re-intervention rate. The aim of this study is to evaluate the current endovascular treatment modalities of endoleak type Ia (ET Ia) treatment after EVAR and their outcome. A systematic review and meta-analysis was performed. MEDLINE, EMBASE and Cochrane databases were searched with PRISMA methodology for studies reporting on endovascular treatment of ET Ia after EVAR. Studies presenting treatment of intra-operative ET Ia were excluded. Two international registries, fourteen non-randomized retrospective and twelve case-report studies were included reporting on 356 patients. Reported endovascular techniques included fenestrated-, branched-, chimney EVAR, endovascular sealing (EVAS), endoanchors, embolization techniques, cuff and/or "giant" Palmaz stents. Technical success rate ranged from 90% to 100%, with intra-operative mortality rate of 0%. During early period, persistence of ET Ia was 3.4% (9/262) and the re-intervention rate was 3.5% (8/227). The 30-day mortality rate was 2% (7/356). Mean follow-up was 22.4 months±18. Presence of ET Ia was 5.9% (21/356), and the reintervention rate was 5.1% (18/349). The mortality rate was 13% (26/203), while the primary patency rate of TVs ranged from 94.3% to 100%. A multitude of techniques for endovascular repair for ET Ia exists. No strong evidence supports one specific technique. The early and mid-term outcomes are encouraging in terms of ET Ia resolution, mortality and morbidity rates.

The Cattell-Braasch maneuver might be a good option for a huge abdominal aortic aneurysm

Endovascular repair is often difficult in the case of a huge abdominal aortic aneurysm for anatomic reasons. Here, we describe open repair of a huge infrarenal abdominal aortic aneurysm. Open repair was performed through laparotomy with the Cattell-Braasch maneuver, a technique for right-sided medial visceral rotation. Laparotomy with the Cattell-Braasch maneuver is simple and effective in open repair of a huge abdominal aortic aneurysm extending into the right common iliac artery, for which proximal clamping is difficult because of a tortuous proximal neck just below the hepatic region.

AB032. 240. Compliance with instructions for use in endovascular abdominal infrarenal aortic aneurysm repair in those aged over 80 years of age

Background: The endovascular aneurysm repair (EVAR) 2 trial advocated not intervening in those deemed unfit for open abdominal aortic aneurysm repair. In the 14 years since EVAR 2 finished recruiting, there have been advances in endovascular technology and expertise, in addition to improvements in anaesthetic and critical care outcomes. These, in concert with an aging population, have led to greater numbers of elderly patients being treated with EVAR. We sought to determine our outcomes when treating this population.

Delayed open conversion after endovascular aortic repair.

We present the clinical outcomes of patients who underwent delayed (>30 days) open surgical repair after endovascular aortic aneurysm repair. All patients receiving delayed open repair of infrarenal and juxtarenal aortic aneurysms after endovascular repair from July 2001 to December 2017 were retrospectively reviewed. Patients' baseline characteristics, indications for delayed open conversion, and time between endovascular repair and open conversion are described. Early outcomes included operative approach, morbidity, and mortality. Midterm outcomes included survival. Twenty-two (3.3%) of 667 patients with prior infrarenal endovascular aortic aneurysm repair had delayed open conversion (20 elective and 2 emergency). The time from endovascular repair to open conversion was 60 ± 36 months. The indications were 6 (27%) type Ia endoleaks, 6 (27%) type II endoleaks with enlarging sac size, 2 (9%) endotensions, 7 (32%) unknown types of endoleak, and 1 (5%) graft infection. The 7 minutes unknown endoleaks were confirmed as lumbar leaks in 4 cases and fabric leaks in 3. Operative time was 222 ± 48 min with blood loss of 2211 ± 2057 mL. Hospital stay after conversion was 12 ± 8 days. There was no 30-day mortality. Estimated survival rates were 96%, 91%, 86%, 79% and 57% at 1, 2, 3, 4, and 5 years postoperatively. Delayed conversion to open surgery after endovascular aortic aneurysm repair by endograft explantation appears to be safe with good short- and mid-term outcomes. With careful preoperative assessment, open conversion remained a realistic and viable option in patients with failed endovascular treatment.

Conservative management of type 1A endoleaks at completion angiogram in endovascular repair of infra-renal abdominal aortic aneurysms with current generation stent grafts.

Proximal type 1A endoleaks on completion intra-operative angiography are not infrequently seen following endovascular abdominal aneurysm repair (EVAR). The natural course of these leaks is not well established. We sought to determine the rate of spontaneous resolution and a conservative treatment approach to these endoleaks. All cases involving endovascular repairs of infra-renal abdominal aortic aneurysms resulting in proximal type 1A endoleak on final intra-operative completion angiography were retrospectively reviewed from 1 April 2010 and 30 March 2015. Demographic, pre and post-procedural imaging, and clinical outcomes were reviewed. Summarizing descriptive statistics are reported. Of the 337 patients who underwent an EVAR, 24 patients (7.1%) had a proximal type 1A endoleak on final intra-operative angiography. Twenty-two of 24 patients (92%) with proximal type 1A endoleaks had spontaneous resolution on follow-up imaging without any intervention, while two (8%) patients had a persistent endoleak. One of these patients required intervention. The median follow-up for patients with resolved endoleaks was 2.5 years vs. 4 and 6 years, respectively, for patients that did not resolve spontaneously. A conservative approach may be used in the management of patients with proximal type 1A endoleaks on completion angiography once maximum proximal seal was achieved intra-operatively as the vast majority of these leaks spontaneously seal.

Cerebral embolization during endovascular infrarenal, juxtarenal, and suprarenal aortic aneurysm repair, high-risk maneuvers, and associated neurologic outcomes

BackgroundRisk factors for postoperative cognitive decline after noncardiac surgery are multifactorial and poorly understood. Evidence suggests that perioperative microembolic damage to the brain on movement of wires and catheters during endovascular aortic procedures may play an important role. Endovascular aortic aneurysm repair requires invasive manipulation of wires and cannulas within the aorta, but research into cerebral emboli during aortic aneurysm repair and cognitive or neurologic injury is scarce and limited to thoracic aneurysms. This study prospectively studied embolic phenomena detected in the middle cerebral artery during infrarenal, juxtarenal, and thoracic endovascular aortic repair (TEVAR) and investigated links to delirium, stroke, and postoperative cognitive decline. MethodsThere were 60 patients who received continuous left-sided perioperative transcranial Doppler monitoring during endovascular aortic aneurysm repair (bifurcated graft for infrarenal aneurysm, n = 18; endovascular aneurysm sealing graft, n = 16; endovascular aneurysm sealing and renal “chimney” stent, n = 17; and thoracic aneurysm, n = 3). The procedure was time stamped for events such as stiff wire insertion and graft deployment. A battery of cognitive tests designed to test several cognitive domains were performed preoperatively and at 90 days postoperatively. ResultsTEVAR and chimney grafts demonstrated significantly greater numbers of total procedural emboli compared with standard bifurcated grafts (mean emboli, 36.2 and 13.39, respectively; bifurcated graft, 5.81; P < .05). The highest risk maneuvers were guidewire and pigtail catheter insertion. This was the case for all procedures including infrarenal aneurysm repair. A higher perioperative embolic load was associated with medium-term cognitive decline in list recall but not with incidence of delirium or stroke. Risk of cognitive decline did not relate to procedure type. Antiplatelet use failed to demonstrate a protective effect. ConclusionsPatients are at risk of cerebral emboli during several types of endovascular aortic surgery, although TEVAR remains the highest risk procedure. As yet, there are no validated protective measures available to prevent cerebral emboli and their associated risks of clinical and subclinical neurologic injury.