Vascular Registry Research Articles

Prognostic Risk Modelling for Patients Undergoing Major Lower Limb Amputation: An Analysis of the UK National Vascular Registry

Major lower limb amputation is the highest risk lower limb procedure in vascular surgery. Despite this, few high quality studies have examined factors contributing to mortality. The aim was to identify independent risk factors for peri-operative morbidity and mortality and develop reliable models for estimating risk. All patients undergoing lower limb amputation above the ankle entered into the UK National Vascular Registry (January 2014-December 2016) were included. Missing data were handled using multiple imputation. Models were developed to evaluate independent risk factors for mortality (the primary outcome) and morbidity using logistic regression, minimising the Bayesian information criterion to balance complexity and model fit. Ethical approval for the study was granted (Wales REC 3 ref:16/WA/0353). All 9549 above ankle joint amputations in the registry were included. Overall, 865 patients (9.1%) died before leaving hospital. Independent factors associated with mortality were emergency admission, bilateral operation, age, American Society of Anesthesiologists' grade, abnormal electrocardiogram, and increased white cell count or creatinine (p<.01 for all). Independent factors reducing mortality were transtibial operation, increased albumin or patient weight, and previous ipsilateral revascularisation procedures (p<.01 for all). A risk model incorporating these factors had good discrimination (C-statistic 0.79, 95% confidence interval 0.77-0.80) and excellent calibration. Morbidity rates were high, with 6.6%, 9.7%, and 4.3% of patients suffering cardiac, respiratory, and renal complications, respectively. The risk model was also predictive of morbidity outcomes (C-statistics 0.74, 0.69, and 0.74, respectively). Morbidity and mortality after lower limb amputation are high in the UK. Some potentially modifiable factors for quality improvement initiatives have been identified and accurate predictive models that could assist patient counselling and decision making have been developed.

Fenestrated Endograft Repair Is Associated With Improved Perioperative Outcomes but Absence of Hospital Volume Relationship in Comparison to Open Surgical Repair of Complex Abdominal Aortic Aneurysms

Complex abdominal aortic aneurysms (cAAAs) have traditionally been treated with an open surgical repair (OSR). During the past decade, fenestrated endovascular aneurysm repair (FEVAR) has emerged as a viable option. During this time, the hospital procedural volume to outcome relationship for OSR of cAAAs has been well established, but the impact of procedural volume on FEVAR outcomes remains undefined. This study investigated the outcomes of OSR and FEVAR for the treatment of cAAAs and examined the hospital volume-outcome relationship for these procedures. A retrospective review of a statewide vascular surgery registry was queried for all patients between 2012 and 2018 who underwent elective repair of a juxtarenal AAA with FEVAR or OSR. The primary outcomes were 30-day mortality, myocardial infarction, and new dialysis. Secondary end points included postoperative pneumonia, renal dysfunction (creatine concentration increase of >2 mg/dL from preoperative baseline), major bleeding, early procedural complications, length of stay, and need for reintervention. To evaluate procedural volume-outcome relationships, hospitals were stratified into low- and high-volume aortic centers on the basis of an annual procedural volume of four juxtarenal AAA repairs per year. To account for baseline differences, we calculated propensity scores and employed probability weighting. A total of 590 patients underwent FEVAR (n = 187) or OSR (n = 403) for cAAAs. After adjustment, OSR was associated with higher rates of 30-day mortality (10.6% vs 3.2%; P = .001), myocardial infarction (3.9% vs 0.81%; P = .29), and need for dialysis (13.5% vs 3.7%; P = .001). Postoperative pneumonia (6.8% vs 0.44%; P = .001) and need for transfusion (35.3% vs 9.6%; P = .001) were also significantly higher in the OSR cohort. The median length of stay for OSR and FEVAR was 9 days and 3 days, respectively. For those who underwent FEVAR, endoleaks were present in 11.6% of patients at 30 days and 5.4% of patients at 1 year, with the majority being type II. One percent of FEVAR patients required a secondary procedure with a median follow-up period of 331 days (229-378 days), and there were no FEVAR conversions to an open aortic repair during this period. Hospitals were divided into low- and high-volume aortic centers on the basis of their annual FEVAR cAAA volume. After adjustment, hospital FEVAR procedural volume was not associated with 30-day mortality or myocardial infarction. FEVAR was associated with lower perioperative morbidity and mortality compared with OSR for the management of complex AAAs. Procedural FEVAR volume-outcome analysis suggests no difference in 30-day morbidity or mortality between low- and high-volume centers, although long-term durability warrants further research.

Cross-clamp location affects short-term survival in patients undergoing open abdominal aortic aneurysm repair

IntroductionOpen abdominal aortic aneurysm (oAAA) repair in the era of advanced endovascular aortic techniques is used in challenging anatomy. The impact of the location of the proximal aortic cross-clamp (suprarenal [SR] vs infrarenal [IR]) on outcomes remains to be determined. The aim of this study was to analyze the effect of proximal aortic cross-clamp location on short-term and overall survival after oAAA repair in a contemporary series. MethodsA retrospective cohort study was performed comparing the outcomes of patients undergoing oAAA repair with SR and IR aortic cross-clamping using the Vascular Quality Initiative registry from January 2003 to September 2018. Our primary end point was short-term mortality. ResultsThere were 7601 patients who underwent oAAA repair. Their mean age was 69.3 ± 8.5 years and 5555 patients (73.1%) were male. The aortic cross-clamp location was IR in 4044 patients (53.2%). The SR group had increased maximum AAA diameter (58 mm vs 56 mm; P < .0001), hypertension (85.5% vs 82.0%; P < .0001), preoperative creatinine (1.11 vs 1.08; P = .001), and were more likely to be in American Society of Anesthesiologists class IV (37.4% vs 30.6%; P < .0001). Postoperative renal failure occurred significantly more often in the SR group (24.4 vs 11.4%; P < .0001). Short-term mortality was 2.7% in the IR group and 4.7% in the SR group (P < .0001). Kaplan-Meier survival estimates were 93.7% and 83.8% in the IR group and 90.9% and 81.2% in the SR group at 1 and 5 years, respectively (P = .007). Multivariable analysis demonstrated that SR cross-clamping was significantly associated with short-term mortality (hazard ratio, 1.38; 95% confidence interval, 1.07-1.78; P = .01); however, it did not affect overall survival (hazard ratio, 1.13; 95% confidence interval, 1.00-1.28; P = .06). ConclusionsA SR cross-clamp location is associated with an increased short-term mortality in patients undergoing oAAA repair. Overall survival is not affected by a SR cross-clamp location.

International Consortium of Vascular Registries Consensus Recommendations for Peripheral Revascularization Registry Data Collection

Introduction - To achieve consensus on the minimal core data set for evaluation of peripheral arterial revascularization outcomes and enable collaboration among international registries. Methods - A modified Delphi approach was used to achieve consensus among international vascular surgeons and registry members of the International Consortium of Vascular Registries (ICVR). Variables, including definitions, from registries covering open and endovascular surgery, representing 14 countries in ICVR, were collected and analyzed to define a minimal core data set and to develop an optimal data set for registries. Up to three different levels of variable specification were suggested to allow inclusion of registries desiring simpler vs. complex data capture, while still allowing for data aggregation based on harmonized core definitions. Results - Among 31 invited experts, 25 completed five Delphi rounds via Internet exchange and face-to-face discussions. In total, 187 different items from the various registry data forms were identified for potential inclusion in the recommended dataset. Ultimately, 79 items were recommended for inclusion in minimal core data sets, including 65 items in the Level 1 dataset, and an additional 14 items in the more specific Level 2 and 3 recommended data sets. Data elements were broadly divided into 1) patient characteristics, 2) co-morbidities, 3) current medications, 4) lesion treated, 5) procedure, 6) bypass, 7) endarterectomy, 8) catheter-based intervention, 9) complications, and 10) follow-up. Conclusion - A modified Delphi study allowed 25 international vascular registry experts to achieve a consensus recommendation for a minimal core data set and an optimal dataset for peripheral arterial revascularization registries. Continued global harmonization of registry infrastructure and definition of items will overcome limitations related to single-country investigations and enhance the development of real world evidence.

The Impact of Centralization and Endovascular Aortic Repair on Treatment of Ruptured Abdominal Aortic Aneurysms Based on International Registries

Introduction - Endovascular aortic repair (EVAR) is the predominant treatment modality for treatment of intact abdominal aortic aneurysms (AAA) in many countries, and its use is also increasing in cases of ruptured AAAs (RAAA).1 Variation in AAA treatment between and within countries influences outcomes of intact AAAs, but little is known on the recent trends and outcomes in RAAA treatment.2 The objective of this analysis was to update recent treatment strategies and outcomes from the Vascunet registry, an international collaboration of vascular surgery registries. Methods - An analysis of all RAAAs from vascular surgical registries in eleven countries from 2010-2013 was carried out. Data were analysed overall, per country, per treatment (EVAR vs. open aortic repair (OAR)), for the volume per centre, divided into quintiles (QI-V), and for centres that were either predominantly EVAR (>50% of rAAA repairs performed with EVAR; pEVAR) or predominantly OAR (pOAR). The primary outcome was perioperative mortality, defined depending on which registry, as either in-hospital or death within 30 days after repair. Data are presented as percentages with 95% confidence intervals (CI), and compared with Chi-square test. Results - There were 9273 patients included. These represented 16.0% (15.7-16.3) of the total number of AAAs operated in this period, ranging from 10.3% (9.8-11.8) in Germany to 29.4% (25.9-32.9) in Finland. The mean age was 74.7 (74.5-74.9), and the majority were men (82.7%, CI, 81.9-83.6). The mean AAA size at the time of rupture was 7.6 cm (7.5-7.6). The perioperative mortality was 28.8% (27.9-29.8), 32.3% (29.9-34.9) for women, greater than for men, 27.1% (26.1-28.2), p <0.001. Perioperative mortality was 32.1% (31.0-33.2) for OAR and 17.9% (16.3-19.6) for EVAR, p<0.001. Perioperative mortality was lower in the highest volume centres (QI, > 22 repairs per year), 23.3% (21.2-25.4), p<0.001. The highest volume centers were also performing the greatest percentage of OAR, 85.6% (83.9-87.4), p<0.001, and all high volume centers (n=13) were pOAR. Perioperative mortality was lower in pEVAR centres (23.0%, 95% CI: 20.6-25.4) vs. pOAR centres (29.7%, 95% CI: 28.6-30.8), p<0.001. Perioperative mortality for OAR was significantly lower in the high volume centres, 25.3% (23.0-27.6), p<0.001. Conclusion - OAR still predominates as the treatment of choice for RAAA treatment, even in the highest volume centres, despite opposite time-trends in intact repair. Perioperative mortality is lower in centres either with high volumes or a predominant EVAR approach to treatment, while results are also better for OAR at centres of high volume. It must be emphasized, however, that this investigation only has reported on those operated on for RAAA. Centralization and EVAR availability favour outcome of those operated on, but there is also a need to study those not offered repair.

Assessment of International Outcomes of Intact Abdominal Aortic Aneurysm Repair over Nine Years

Introduction - Case mix and outcomes of complex surgical procedures vary over time and between regions.1 With noted increasing surgical activity and screening programmes for abdominal aortic aneurysm (AAA) detection and management, the monitoring of surgical outcome measures is increasingly important.2–4 The objective of this study is to describe trends in contemporary AAA practice in an international context, and assess the change in perioperative mortality after repair. Methods - Data on primary AAA repair from vascular surgery registries in 11 countries for the years 2005-2009 and 2010-2013 were analyzed. Data were analyzed overall, per country, per treatment (EVAR vs. open surgery), for high- and low-volume centres, and also between the two time periods (2005-2009 and 2010-2013). The primary outcome was perioperative mortality, defined as either in-hospital death or death within 30 days. Multivariable-adjusted logistic regression analyses were carried out to adjust for variations in case mix. Results - There were 83 253 patients included. Over the two periods, the proportion of patients ≥80 years old increased (18.5% vs. 23.1%; p<0.0001), as well as endovascular repair (EVAR) (44.3% vs. 60.6; p<0.0001). AAAs less than 5.5 cm in the latter period was 25.8%. The mean annual volume of open repairs per center decreased from 12.9 to 10.6 between the two periods, p<0.0001, while it increased for EVAR from 10.0 to 17.1, p<0.0001. Overall, perioperative mortality fell from 3.0% to 2.4% (p<0.0001). Mortality for EVAR decreased from 1.5% to 1.1% (p<0.0001), while the outcome worsened for open repair (3.9% vs. 4.4%, p=0.008). The perioperative risk was greater for octogenarians (Overall, 3.6% vs. 2.1%, p<0.0001; Open, 9.5% vs. 3.6%, p<0.0001; EVAR, 1.8% vs. 0.7%, p<0.0001), and women (Overall, 3.8% vs. 2.2%, p<0.0001; Open, 6.0% vs. 4.0%, p<0.0001; EVAR, 1.9% vs. 0.9%, p<0.0001). Perioperative mortality after repair of AAAs<5.5 cm was 4.4% with open repair and 1.0% with EVAR, p<0.0001. Conclusion - In this large international cohort, total perioperative mortality continues to fall for the treatment of intact AAAs. EVAR procedures now exceed the number of open procedures. Mortality after EVAR has decreased, while mortality for open operations has increased. The perioperative mortality for small AAA treatment, particularly open surgical repair, is still considerable and should be weighed against the risk of rupture. References1Beck AW, Sedrakyan A, Mao J, Venermo M, Faizer R, Debus S, et al. Variations in Abdominal Aortic Aneurysm Care: A Report from the International Consortium of Vascular Registries. Circulation 2016;134(24):1948–58.2Schwarze ML, Shen Y, Hemmerich J, Dale W. Age-related trends in utilization and outcome of open and endovascular repair for abdominal aortic aneurysm in the United States, 2001-2006. J Vasc Surg 2009;50(4):722-9.e2.3Chun KC, Teng KY, Van Spyk EN, Carson JG, Lee ES. Outcomes of an abdominal aortic aneurysm screening program. J Vasc Surg 2013;57(2):376–81.4Mani K, Lees T, Beiles B, Jensen LP, Venermo M, Simo G, et al. Treatment of abdominal aortic aneurysm in nine countries 2005-2009: A vascunet report. Eur J Vasc Endovasc Surg 2011;42(5):598–607.

Translation and Validation of the Swedish Venous Health Questionnaire in Patients with Venous Insufficiency

Introduction: When assessing the treatment of Chronic venous disease (CVD), both treatment outcomes and quality of life are recommended. In a recent study our group translated into Swedish and validated the first disease specific instrument for CVD in Sweden, VEnous Insufficiency Epidemiological and Economic Study on Quality of Life/Symptoms (VEINES-QOL/Sym-Swe). This 26-item instrument even though thorough is tedious in the clinical setting. The VVSymQ instrument is a five-item patient-reported outcome (PRO) that assesses symptoms most important to patients with varicose veins (VV), heaviness, achiness, swelling, throbbing and itching. The instrument is based on the symptom domain of the VEINES-QOL/Sym questionnaire and has been thoroughly validated in English and is used in the Vascular Quality Registry for Varicose veins with two added questions about activity and appearance.The aim of this study was to create a Swedish version of the seven-item VV questionnaire and validate it in a Swedish cohort of patients with venous disease. Methods: The original questionnaire was translated into Swedish and administered to 257 patients consecutively recruited with varying degrees of chronic venous disease. Patients from three private clinics were asked to complete both the VEINES-QOL/Sym-Swe and the VV questionnaire (VVQ) at the first consultation, 1 week later and 8 weeks after surgery. Results: In total 257 patients were included. The mean age was 58.1 ± 15.1 years (range 20 - 93) and 60% of the participants were female. The results showed excellent internal consistency for the VVQ (Cronbach's alpha (α) = 0.87). VEINES-QOL/Sym-Swe and the VVQ correlated well as regards to the item question on appearance as well as when the symptom domain from both questionnaires was compared, demonstrating good construct validity. When the preoperative and postoperative VVQ was compared in the specific domains of heaviness, achiness, throbbing, swelling, itching, appearance, and work impact, improvements were seen (total score change, 9.06 ± 6.17; n = 36; P < .001) from a mean preoperative VVQ score of 14.00 ± 7.18 to a mean postoperative VV questionnaire score of 4.94 ± 4.85.The C-class of the CEAP-classification had no significant correlation with the Swedish VVQ. Conclusion: The Swedish version of the short VV questionnaire is reliable and can be used for Swedish patients treated for varicose veins. Disclosure: Nothing to disclose

Reduced Recurrent Ischemic Event Rate for Patients Undergoing Invasive Carotid Artery Intervention

Introduction - Patients with a symptomatic carotid artery stenosis risk a recurrent ischemic event during the waiting time to intervention or in the perioperative period. As the risk of recurrence is highest in the early phase after the presenting event, recent strategies recommend short delay to intervention but there are concerns that the possible benefit from early intervention may be counterbalanced by an increased perioperative complication rate. The aim of this national audit was to study the effects of more expedient carotid intervention on the risk of recurrent ischemic events. Methods - The Swedish Vascular Registry (Swedvasc) covers all centers in the country performing carotid interventions, and all registrations for symptomatic carotid artery stenosis from May 2008 to December 2015 were analyzed, focusing on recurrent ischemic events in the delay to surgical intervention and during the 30-day perioperative follow-up. The National Prescribed Drug Registry provided data on preventive medications prior to hospitalization for the carotid procedure. Results - In Swedvasc 6814 procedures for symptomatic carotid stenosis were registered during the time period. The mean age was 72 (±8) years and 68% were male. The presenting events were TIA in 58%, amaurosis fugax in 22% and stroke in 20%. Baseline demographic variables, comorbidities and secondary prevention pharmacotherapy when admitted for the procedure was similar during study period. The waiting time from the presenting neurological event to carotid intervention decreased from 13 (IQR 6-27) to 7 days (IQR 4-12) during the study period. Importantly, the proportion of recurrent ischemic events decreased over time from 30% (CI 28-33%) in 2008-2009 to 21% (CI 19–23%) in 2014-2015 (p< 0.01, χ2test). The perioperative stroke and/or death rate was 3.6%, with a decreasing trend during study period (5.3% 2008-2009 vs. 3.2% 2014-2015, p=0.05). Conclusion - In this population-based study, the overall risk for a recurrent ischemic event, from the presenting event until the 30-day follow-up, was markedly decreased during the time period. Efforts in reducing the delay to surgery were not counterbalanced by any increase in the perioperative complication rate.

The Weekend Effect in Non-Elective Abdominal Aortic Aneurysm Repair

Introduction - The ‘weekend effect’, first described in 2001, is a hotly debated topic1. It describes the phenomenon where patient outcomes appear worse for those admitted at the weekend when compared to those treated during the week. It has been used recently to justify significant changes in health policy2. Recent evidence has suggested that the effect may be due to a combination of inadequate correction for confounding factors and inaccurate coding3. We investigated the effects of these factors in patients with acute abdominal aortic aneurysm (AAA). Methods - All patients undergoing non-elective AAA repair entered into the prospectively collected National Vascular Registry from January 2013 until December 2015 were included in the study, with patients divided in a case-control study according to whether they were treated during the week (between 8am Monday and 5pm Friday) or at the weekend (between 5pm Friday and 8am Monday). Coding issues were investigated by looking separately at patients treated for ruptured, symptomatic or asymptomatic AAA within the non-elective cohort. The primary outcome was in-hospital mortality. Secondary outcomes included length of inpatient stay and cardiac, respiratory and renal complications. Results - Mortality appeared to be higher at the weekend (odds ratio (OR) 1.65, 95% confidence interval (CI) (1.44–1.89), P<0.001), but this effect disappeared when confounding factors and coding issues were corrected for (corrected OR for ruptured AAA 1.09, 95% CI (0.92–1.29), P=0.33). Differences in outcomes were similar for prolonged length of stay (uncorrected OR 1.42, 95% CI (1.26–1.60), P<0.001; corrected OR for ruptured AAA 1.06, 95% CI (0.91–1.10), P=0.48) and morbidity outcomes. Conclusion - After appropriate correction for confounding factors and coding effects, there is no evidence of a significant ‘weekend effect’ in the treatment of non-elective AAA within this large cohort. Further work is warranted to determine whether previously reported ‘weekend effect’s in other areas are robust to more rigorous statistical analysis.

Contemporary Outcomes Following Infra-inguinal Bypass. A Recent Vascular Hub Exeprience

Introduction: Infra-inguinal bypass is the most common surgical procedure performed for critical lower extremity ischaemia. Outcomes in-terms of; survival, graft patency and freedom from major amputation vary significantly in the literature and are influenced by many factors including patient co-morbidity, anatomical site of bypass and choice of bypass conduit. Here is presented contemporary outcomes of all infra-inguinal bypass grafts performed at a single vascular hub between January 2015 and January 2019. Methods: This is a single centre, retrospective cohort study. Demographic, disease and procedural data was extracted from eligible cases identified within a national vascular registry (VSQIP-NVR). This was then cross-referenced with hospital episode statistic (HES) codes to ensure adequate data capture. In-house electronic records (clinical results reporting system, CRRS) were interrogated for follow up, re-intervention and survival outcome measures. Statistical analysis was performed using SPSS 25 (IBM). Survival estimates were calculated using the Kaplan-Meier method. Results: 185 Eligible infra inguinal bypass procedures were Identified. This consisted of 79 elective and 106 non-elective admissions. Mean age at surgery was 69 (±13) years. Tissue loss was present in 46%(n=85) of patients. Autologous vein was the conduit of choice in 90% (n=165) with reversed vein and in-situ vein accounting for 76% (n=143) and 14% (n=26) respectively. 87% of patients were enrolled into ultrasound surveillance. Mean duration of follow up was 42 (0-51) months. At 6 months, 1 and 3 years primary patency was 68%, 60% and 54% respectively.Mean time to first intervention was 14 months (IQR 3-22 months). 88% of all interventions to maintain patency were carried out by 24 months.At 6 months, 1 and 3 years secondary patency was 93%, 88% & 86% respectively. At 6 months, 1 and 3 years limb salvagewas 85%, 81% & 79% respectively. Estimated survival and limb salvage rates were significantly lower in non-elective procedures in comparison to elective procedures (p=0.07 & p=0.03 respectively). There was no difference in primary or secondary patency between popliteal and distal bypasses, however, limb salvage was significantly better in popliteal bypasses (p=0.03). Conclusion: Infra-inguinal bypass remains the gold standard in lower limb revascularisation. This case series highlights excellent patency and limb salvage into the medium term. We would advocate ultrasound surveillance as a significant proportion (38%) of grafts require maintenance to ensure continued patency, our data would support a surveillance period of 24-months as sufficient, 88% of all graft interventions to maintain patency were performed by 24 months. It may be possible limit graft surveillance, provided patients have been intervention free. As anticipated, patients who undergo non elective bypass are at greater risk of major amputation than their elective counterparts. Disclosure: Nothing to disclose

Gender Differences of the Oucome After Revascularization Fo Carotid Artery Stenosis – Vascunet Study

Introduction: The aim of this study was to compare short-term outcome after revascularization of carotid stenosis between males and females. Methods: Data on carotid endarterectomies (CEA) and stentings (CAS) from fifteen national or regional vascular registries were collected and amalgamated using common data sets accepted by all participants. Data were collected from 2009 to 2017. Primary endpoint was combined stroke - and death rate. Also, impact of delay was analyzed in both genters. Results: A total of 207638 (55% CEAs, 45% CASs) patients were included, 65% were male (n=135137) and 35% female (n=72501). The proportion of symptomatic patients was 49% among males and 47% among females. 30-day combined stroke and death rate after CEA for asymptomatic males and females was 2.5% vs. 2.6% (p=0.4), combined death, stroke and myocardial infarction rate 3.5% vs. 3.8% (p=0.2). Mortality was slightly higher among males (0.9% vs. 0.7%; p=0.048). Among symptomatic patients the corresponding rates were 2.4% vs. 2.5% (p=0.7), 3.0 vs. 3.2% (p=0.4) and 0.9% vs. 1.1% (p=0.2). After CAS, 30-day combined stroke and death rate in asymptomatic males and females was 2.8% vs. 2.8% (p=0.8), combined death, stroke and myocardial infarction (MI) rate 3.8% vs. 3.9% (p=0.5). Mortality was 0.9% vs. 0.8%; p=0.08). In symptomatic patients after CAS the corresponding rates were 2.7% vs. 2.8% (p=0.6), 4.0 vs. 4.2% (p=1.0) and 0.9% vs. 1.0% (p=0.5). After CEA no gender differences were present when analysis was done separately among patients under or over 75 years of age. After CAS for symptomatic patients < 75 years of age, females had higher combined stroke and death rate than males (2.5% vs. 3.1%;p=0.03). Delay from the index symptom to the procedure was available from 5 countres and alltogether from 25767 CEA patients. Delay was analyzed in 5 cathegories: < 2 days, 2-7 days, 4-14 days, 14 days-6 months and >6 months. Combined stroke and death rates in these 5 groups were in males 4.6%, 2.4%, 2.4%, 2.1% and 1.5% compared to 4.3%, 2.9%, 2.2%, 1.9% and 1.8% in females. In the binary logistic regression analysis, independent risk factors for combined stroke or death were age (OR 1.1/10 years, p=0.000), CAS compared to CEA (OR 1.1, p=0.004) and delay < 2 days (OR 3.1, p=0.000). Gender was not significant risk factor for stroke and/or death (OR 1.04, 95% CI 0.98-1.1, p=0.2). Conclusion: No gender differences were seen in the short-term outcome after CEA. Combined stroke and death rate is higher when CEA is performed less thant 2 days after index symptom in both genders. Disclosure: Nothing to disclose

A Nationwide Study on Endovascular Treatment of Mycotic Thoracic Aortic Aneurysms

Introduction - Mycotic aortic aneurysms are rare, life threatening and complex. Current knowledge on treatment is scarce and based on small single-centre case series with heterogenic case-mixes. This nationwide multicentre study aims to assess endovascular treatment for mycotic aneurysms of the thoracic aorta (MTAAs). Methods - All patients treated endovascularly for MTAAs between 2010 and 2016 were identified in the national vascular registry. All eight tertiary vascular units in the nation participated in retrieving data and retrospective chart review according to a predefined protocol. Results - 42 patients were identified, and two additional patients were treated with open repair. Median age was 71 years (Standard deviation SD 7.4), 23 (55%) were men, 32 (76%) had cardiovascular comorbidity, 12 (29%) were immunosuppressed, and 11 (26%) presented with rupture. The aneurysms were located in the aortic arch in 5 patients (12%), descending aorta in 33 (79%), and multiple locations including the thoracic aorta in 4 (9%). Positive culture was obtained in 21 (50%). The two most prevalent infectious agents were Stafylococcus aureus (n=11, 25% of all MTAA patients), and Streptococcus sp (n=3, 7%). Thoracic endovascular aortic repair (TEVAR) was performed (n=31), fenestrated/branched TEVAR (n=5), and hybrid visceral deviation and stentgrafting (n=6). Total survival was at 3-months 86% (95% CI 81-91%), 1-year 80% (74-86%), and 5-years 73% (66-80%). Mean follow-up among survivors (>90-days) was 35 months (range 4-212). Antibiotics were administered for a median of 7 weeks, range 0-220 weeks. Infection-related complications occurred in 6 patients (14%); sepsis n=2, graft infection n=1, recurrent mycotic aortic aneurysm=1, and aorto-esophageal/brochial fistula n=2. All occurred within the first year. Both cases with aortic fistulation died, the patient with graft infection was converted to an open procedure with explantation of the graft and survived, the recurrent mycotic aneurysm was treated with stentgraft and antibiotics and survived, and the two sepsis cases were treated successfully with antibiotics. Reoperation was performed in 8 patients (18%; infection-related complication n=3, endoleakage n=4, and stent graft occlusion n=1), of which one was converted to an open procedure. Seven patients (17%) had an aneurysm-related death. Conclusion - In this nationwide analysis of endovascularly treated MTAA-patients survival was acceptable. This minimally invasive treatment enabled surgical repair in elderly, comorbid patients with a challenging anatomy with acceptable rates of infection-related complications and reoperation.

Abdominal Compartment Syndrome After Abdominal Aortic Aneurysm Repair: Subgroups, Risk Factors and Outcome

Introduction - Abdominal compartment syndrome (ACS) remains a lethal complication after abdominal aortic aneurysm (AAA) repair. The aim of this population-based cohort study was to investigate factors associated with outcome. Methods - Since 2008, postoperative ACS and decompression laparotomy after AAA repair are registered prospectively in the National vascular registry. The case records of all patients registered for ACS 2008-2015 were reviewed. The main pathophysiological mechanism seen at laparotomy was defined and the duration of intra-abdominal hypertension (IAH) prior to decompression was registered. Results - In all 119 patients from 24 vascular centres were included in the study. Among 82 repairs for ruptured AAA (rAAA), there were 44 Open surgical repairs (OSR) and 38 endovascular aortic repair (EVAR), and among 37 repairs for intact AAA (iAAA), there were 30 OSR and 7 EVAR. Mortality did not differ between EVAR and OSR for rAAA but was higher after EVAR for iAAA at one-year (6/7 [85.7%] versus 9/30 [30.0%], p=.011). Patients treated with EVAR for rAAA reached peak intra-abdominal pressure (IAP) values, and had DL earlier, than those treated with OSR (Both p<.001). Decompressive laparotomy (DL) was performed within twenty-four hours in 55 (48.2%) patients, between twenty-four and forty-eight hours in 30 (26.3%) and after forty-eight hours in 29 (25.4%). There were three main findings at DL: bowel ischemia in 27 (23.5%), postoperative bleeding in 34 (29.6%) and general oedema/fluid overload in 54 (47.0%). Mortality did not differ depending on findings at DL, figure 1, or timing of DL. Ninety-day non-survivors (60/119, 50.4%) were older (p<.001), had larger aneurysms (p=.045), received more intraoperative blood transfusions (p=.001) and were more often treated with suprarenal clamping/balloon occlusion (p<.001), compared to those who survived 90 days or longer after surgery. In multivariable regression analysis, only age was a predictor for one-year mortality (p=.026). Duration of intra-abdominal pressure ≥15 and ≥20 mmHg prior to DL were independent predictors for the need of renal replacement therapy (RRT) (p=.041 and p=.031). Open abdomen treatment was performed in 106 patients of whom 98 (92.5%) received negative pressure wound therapy (NPWT), which in a majority also was combined with mesh-mediated traction. Among 85 patients with NPWT who survived until the abdomen was closed, 81 (95.3%) achieved primary delayed fascial closure. Conclusion - Mortality in ACS did not differ depending on the cause of ACS or on whether DL was performed early, intermediate or late. The duration of IAH prior to DL affected the need for RRT, suggesting the value of close monitoring and early treatment of IAH to prevent renal failure. ACS after EVAR for rAAA developed early after surgery, and in this clinical scenario monitoring of IAP may be life-saving.

Outcome of Thoracic Endovascular Aortic Repair in 8 Countries – Report from an International Registry Collaboration

Introduction: Thoracic endovascular aortic repair (TEVAR) has rapidly developed to the primary treatment modality for most pathologies of the descending thoracic aorta. Practice patterns and short-term outcome regarding TEVAR was assessed based on an international vascular registry collaboration. Methods: Data on TEVAR procedures were retrieved from national, regional and centre-specific registries in eight countries located in Europe and Australasia. All thoracic aortic aneurysms (TAA), aortic dissections (AD), and traumatic aortic injuries (TAI) treated with TEVAR during the period 2012-2016 were included. Results: 1919 TEVAR procedures performed because of TAA n=994, AD n=692 and TAI n=233 were included. The distribution of TEVAR procedures for each pathology differed between countries (p< 0.001), Figure 1. Mean age was TAA 71.6, AD 63.5 and TAI 47.1 years (p< 0.001). The majority of the treated patients were men; TAA 64%, AD 77%, TAI 79%. The proportion of ruptured TAA varied from 9% to 39% between countries (p=0.001). Mean maximal aortic diameter varied from 60.1-69.1 mm for intact aneurysms (p=0.018). Mean maximal aortic diameter for ruptured aneurysms was 68.6 mm. 68% of AD were treated in acute and 32% in chronic phase, the proportions did not differ significantly between countries. Indications for TEVAR of acute dissection were: refractory pain 27%, visceral ischemia 24%, rupture 21%, dilatation 18%, extremity ischemia 5% or other reasons 5%. Chronic dissection was treated because of dilatation 75%, refractory pain 9%, rupture 6%, extremity ischemia 2%, visceral ischemia 1% or other reasons 7%. Mean maximal aortic diameter was 45.1 mm for acute and 61.6 mm for chronic dissection. 93% of TAI were treated emergently. The rates of perioperative mortality, stroke, paraplegia and renal failure requiring renal replacement therapy are presented in Table I. The rates of perioperative mortality and renal failure differed significantly depending on indication for TEVAR. Conclusion: The results of this broad registry-based analysis of TEVAR indicate that there are international differences in clinical practice. Short-term outcome after TEVAR depends on pathology, and is adequate compared with previous studies on endovascular and open surgical repair of thoracic aortic pathology.Table IPerioperative mortality and complicationsTable IPerioperative mortality and complications Disclosure: Nothing to disclose

Outcome After Endovascular Repair of Ruptured Thoracic Aortic Aneurysm: A National Multicenter Study

Introduction - Ruptured descending thoracic aortic aneurysm (rDTAA) is an acute condition with high mortality requiring urgent treatment. The purpose of this multicenter study was to analyze the outcome of thoracic endovascular aortic repair (TEVAR) in patients with rDTAA. Methods - This is a nationwide retrospective study including all patients who underwent TEVAR for rDTAA at six major vascular university centers in Sweden between January 2000 and December 2015. Data from local hospital records and the Swedish vascular registry at the participating centres were reviewed. Outcome measures were analysed using Kaplan-Meier estimator and multivariable Cox-regression. Results - There were 140 patients (mean age 74.1±SD 8.8 [range: 34-91] years; 56% men), with rDTAA. The mean descending aortic aneurysm size was 64.8±19 mm. Hemothorax was present in 64% (89/139) of patients at admission. The median stent graft length was 218 mm (range: 30-800 mm) and the median number of stentgrafts used was 2.0 (range: 1-6). In 53 patients (37.9%), the left subclavian artery was covered to extend the proximal landing zone. Twenty-five patients (17.9%) required proximal revascularization; chimney left carotid artery (n=14), chimney left subclavian artery (n=7), carotid-carotid-subclavian bypass (n=2), and left carotid-subclavian bypass (n=2). The celiac trunc was covered in 15 cases (10.7%) to achieve adequate distal landing zone. A chimney was placed in the SMA in six cases (4.3%) and in the celiac trunc in one case (0.7%). In two patients a multi branched stent graft was used. In total, 61/136 patients (45%) had a major complication within 30-day post TEVAR. Stroke (n=20; 14.7 %) was the most common complication followed by paraplegia (n=13; 9.6%) and major bleeding (n=13; 9.6 %). There were no association between stent graft length or subclavian coverage and paraplegia (OR 1.00, 95% CI 0.998-1.01; P=0.32, and OR 0.56, 95% CI 0.14-2.31; P=0.42; respectively) or subclavian coverage and stroke (OR 1.40, 95% CI 0.46-4.31; P=0.56). Reinterventions were required in 27/137 patients (19.7%). Postoperative bleeding was the only major complication associated with reintervention (OR 3.39, 95% CI 1.05-11.0; P=0.042). Median follow-up time was 18.5 months (range: 0-132 months). The Kaplan-Meier estimated survival was 79.1% at 1 month, 70.8% at 3 months, 64.5% at 1 year, 45.0% at 3 years, and 30.9% at 5 years. Age (HR 1.04; 95 % CI 1.00-1.07; P=0.044), previous stroke (HR 2.31; 95 % CI 1.17-4.55; P=0.016), previous aortic surgery (HR 2.17; 95 % CI 1.18-3.99; P=0.012) as well as postoperative major bleeding (HR 4.29; 95 % CI 2.14-8.60; P=0.001), postoperative stroke (HR 2.73; 95 % CI 1.43-5.22; P=0.002), and renal failure (HR 7.82; 95 % CI 2.53-24.19; P=0.001) were all associated with mortality. Conclusion - This nationwide multicenter study of patients with rDTAA undergoing TEVAR showed acceptable short-term survival but the long-term survival is rather poor. The postoperative complication rate is high and reinterventions are required in one fifth of patients. Patient selection and optimization are of utmost importance to improve outcome.

Ultrasound Surveillance of Insitu Bypass Grafts - is it Worth the Effort?

Introduction: In surgical fit patients with critical limb ischaemia (CLI) a great saphenous vein bypass is the recommended treatment for long occlusions of the infra-popliteal segment ADDIN EN.CITE ADDIN EN.CITE.DATA 1. Development of vein graft stenosis and bypass failure is observed in as much as 40% within the first 12 months2 and duplex ultrasound (DUS) surveillance has been broadly implemented with the aim to increase patency. ADDIN EN.CITE ADDIN EN.CITE.DATA Nevertheless, the evidence supporting this many DUS examinations are conflicting. ADDIN EN.CITE ADDIN EN.CITE.DATA 2, 3 Most cohorts in the literature are heterogeneous and report on a variety of autogenous vein conduits (insitu vein, reversed vein, arm vein and spliced vein) and indications (claudication or CLI) making generalizability difficult.3 The aim of this study was to describe patency of insitu saphenous vein bypass (ISSVB) in critical limb ischaemia and to analyse the added value of systematic DUS surveillance of in situ saphenous vein bypass. Methods: Single centre study including all patients undergoing ISSVB surgery due to CLI between 2011 and 2015. Postoperative graft surveillance program were offered to all patients, including clinical examination, ABI and DUS at 6 weeks, 3 and 12 months. The study was based on prospective entered data from the Danish Vascular Registry and primary endpoints were re-intervention rate and patency. To avoid idealization of the survival plots we decided to include occlusion, amputation and death as endpoints in both plots and use reintervention as the only variable in the Kaplan Meyer estimates. Results: In total 392 consecutive and treatment naive CLI-patients were revascularized with ISSVB and included in the study. Of those, 326 patients had minimum one follow up visit resulting in 1267 DUS examinations. During the study period, 95 (24%) patients received 143 reinterventions to avoid graft failure, 76 patients (80%) with percutaneous transluminal angioplasty (PTA) and 19 patients (20%) with surgical revision. Only 18 patients (20 reinterventions) were revised solely based on DUS findings (significant stenosis) without simultaneous ischemic symptoms or significant (>15%) decrease in ankle brachial index. Hence, to find one asymptomatic graft stenosis requiring reintervention one need to scan 65 patients (1267:20=65). Occlusion- and amputation-free survival (OAS) after 1, 2 and 3 years was 59.7% (95%-CI: 54.6-64.5), 45.3% (39.6-50.9) and 32.3% (26.4-38.4), respectively (figure 1). Reintervention-, occlusion-, and amputation-free survival (ROAS) after 1, 2 and 3 years was 47.6% (42.5-52.6), 33.5% (28.1-38.9) and 21.1% (16.0-26.7). Conclusion: The KM-plots showed a significant difference between ROAS and OAS until 2½ years postoperatively, indicating a modest (approximately 10%) effect of reintervention on graft stenosis. In this study, every fourth of ISSVB patients received a graft-preserving intervention but very few were driven by routine DUS as most graft lesions were recognised on symptoms and clinical findings. This finding suggests that development of more individualised surveillance programs differentiating between high and low risk patients may be more cost effective. Disclosure: Nothing to disclose

Early- and Long-term Outcome After Endovascular Treatment of Chronic and Acute on Chronic Mesenteric Ischemia in a Large National Cohort

Introduction: Treatment of chronic mesenteric ischemia has evolved from open surgery towards endovascular revascularization in most centers(1). The endovascular approach includes a low early morbidity, shorter lengths of hospital stay (LOS) and early recovery despite higher risk of restenosis and lower patency compared to open repair(2,3). Long-term outcome after endovascular treatment remains to be proven in larger series. The objective of this study was to assess early- and long-term outcome after endovascular revascularization of chronic (CMI) and acute on chronic (AoCMI) mesenteric ischemia in a large national cohort. Methods: All patients treated endovascularly due to CMI or AoCMI between 2011 and 2015 were included. Patients with acute mesenteric ischemia (embolic) or previous open mesenteric revascularization were excluded. Treatment of mesenteric ischemia in our country is centralized to one tertiary vascular referral center, why this study represents a national cohort. Prospectively entered data were extracted from the National Vascular Registry. Subsequently, electronic records and PACS were manually and retrospectively assessed. Endpoints included technical success rate, early- (mortality, bowel resection, complications, LOS) and long-term- (1-3 year mortality, symptom relief) outcome. Potential outcome predictors were evaluated. Results: In total, 246 patients with CMI or AoCMI were included. The clinical presentation was CMI in 178 patients (mean age 70; women 68%) and AoCMI in 68 patients (mean age 69; women 69%). 30-day mortality in the CMI and AoCMI group was 2% (n=3) and 16% (n=11), respectively (p < .0001). The CMI group had significantly better survival rates after one and three years, with Kaplan Meier (KM) estimates of 85% (95% CI 78.7-89.3) and 73% (95% CI 66.0 - 79.3) in the CMI group compared to 66% (95% CI 53.4 - 76.0) and 53% (95% CI 40.3 - 64.4) in the AoCMI group (figure 1). Independent predictors of death were AoCMI vs CMI (HR = 1.8 (p< .01)) and hypertension in the CMI group (HR =2.7 (p=.001)). Based on angiography, we found no correlation between outcome and number of diseased vessels. Five patients (3%) in the CMI group and 30 patients (44%) in the AoCMI group underwent bowel resection. LOS was seven times longer in the AoCMI group (mean 20 days (95% CI 12.4-27.6)) compared to the CMI group (2.9 days (95% CI 2.4-3.3)). Symptom relief after one year was identical; (60% (n=107) vs. 53% (n=36) in the CMI and AoCMI group, respectively (p= .3). Reintervention due to symptom recurrence and target artery restenosis was performed only in 10 patients (6%) in the CMI group and 1 patient (1%) in the AoCMI group after mean 219 days (95% CI 89.1-349)) and 423 days respectively. Five access-related complications (2%) needed reintervention, target-vessel related complications were seen in 7 patients (3%) and 1 patient had cerebral embolization. Conclusion: First-line endovascular treatment of CMI and AoCMI is related with acceptable short- and long-term outcome and a low risk of symptomatic restenosis. As expected, patients suffering AoCMI have significantly higher mortality, more bowel resection and longer LOS compared to CMI patients, underlining the importance of early diagnosis and treatment of CMI. Disclosure: Nothing to disclose

Risk Factors for In-hospital Mortality Following Major Lower Limb Amputation: Analysis of 10,000 Patients' Data from the UK National Vascular Registry

Risk Factors for In-hospital Mortality Following Major Lower Limb Amputation: Analysis of 10,000 Patients' Data from the UK National Vascular Registry

Abdominal Compartment Syndrome after Surgery for Abdominal Aortic Aneurysm: Subgroups, Risk Factors, and Outcome

Objectives Abdominal compartment syndrome (ACS) is a serious complication after abdominal aortic aneurysm (AAA) repair. The aim was to investigate outcome among subgroups and factors associated with outcome, with emphasis on the duration of intra-abdominal hypertension before treatment. Methods Since 2008, ACS and decompressive laparotomy (DL) after AAA repair are registered prospectively in the Swedish vascular registry (Swedvasc). Registry data and case records were reviewed. Subgroups were defined by main pathophysiological finding at DL, timing of DL after AAA repair, and treatment modality. Results During 2008–2015, 120 of 8765 patients undergoing surgery for infrarenal AAA developed post-operative ACS (1.4%). Eighty-three followed ruptured AAA (rAAA); 45 open surgical repairs (OSR) and 38 endovascular (EVAR), and thirty-seven after intact AAA (iAAA); 30 OSR and seven EVAR. The main pathophysiological findings at DL were bowel ischaemia in 27 (23.3%), post-operative bleeding in 34 (29.3%), and general oedema in 55 (47.4%). DL was performed 48 hours in 29 patients (25.2%). The overall 90 day mortality was 50.0%, neither different depending on main pathophysiological finding, nor on the timing of DL. In multivariable regression analysis, age was a predictor of mortality (p = .017), while duration of intra-abdominal hypertension (IAH) prior to DL predicted the need for renal replacement therapy (RRT) (p = .033). DL was performed earlier after EVAR compared with OSR in rAAA (p Conclusions Mortality in ACS was high, irrespective of the main pathophysiological finding and timing of DL. The duration of IAH prior to DL predicted the need for RRT. DL was performed earlier after EVAR than after OSR for rAAA, underlining the importance of monitoring IAP after EVAR for rAAA.

Impact of Frailty on Outcomes in Patients Undergoing Open Abdominal Aortic Aneurysm Repair

Frailty is a global state that does not relate directly to comorbidities and is prevalent among patients with vascular disease. The Clinical Frailty Scale (CFS) is a rapid assessment tool to identify vulnerable and frail patients. In this study, we sought to evaluate whether the preoperative CFS score could be used to independently predict mortality and morbidity after elective open abdominal aortic aneurysm (AAA) repair. We retrospectively reviewed our institutional National Vascular Registry (NVR) data to identify all patients who underwent an elective open juxta or infrarenal AAA repair between January 2014 and December 2018. The NVR data set included preoperative risk factors, imaging findings, intraprocedural variables, and postprocedural outcomes. A total of 184 patients were assessed using the CFS before they underwent elective open AAA repair. Among 26 (14%) individuals categorized as vulnerable using the CFS, there was no significant difference in age or preoperative cardiac and respiratory testing compared with nonfrail patients. However, vulnerable patients were significantly more likely to have a longer length of stay (12.2days vs. 8.8days, P-value 0.044), suffer from respiratory complications (35% vs. 15%, P-value 0.022) and renal failure (23% vs. 6%, P-value 0.013), or die (23% vs. 2%, P-value 0.0003). The regression analysis identified a vulnerable frailty score to be the only significant predictor of mortality (odds ratio=36.7, P<0.001), all other factors were not shown to be independent predictors. The CFS is a practical tool for assessing preoperative frailty among patients undergoing elective open AAA repair and can be used to predict mortality and morbidity after surgery.