Dutch Surgical Aneurysm Audit Research Articles

Administrative healthcare data as an addition to the Dutch surgical aneurysm audit to evaluate mid-term reinterventions following abdominal aortic aneurysm repair: A pilot study

BackgroundThe Dutch Surgical Aneurysm Audit (DSAA) is a nationwide mandatory quality registry that evaluates the perioperative outcomes of abdominal aortic aneurysms (AAAs). The DSAA includes perioperative outcomes that occur up to 30 days, but various complications following AAA repair occur after this period. Administrative healthcare data yield the possibility to evaluate later occuring outcomes such as reinterventions, without increasing the registration burden. The aim of this study is to assess the feasibility and the potential benefit of administrative healthcare data to evaluate mid-term reinterventions following intact AAA repair. MethodAll patients that underwent primary endovascular aneurysm repair (EVAR) or open surgical repair (OSR) for an intact infrarenal AAA between January 2017 and December 2018 were selected from the DSAA. Subsequently, these patients were identified in a database containing reimbursement data. Healthcare activity codes that refer to reinterventions following AAA repair were examined to assess reinterventions within 12 and 15 months following EVAR and OSR. ResultsWe selected 4043 patients from the DSAA, and 2059 (51%) patients could be identified in the administrative healthcare database. Reintervention rates of 10.4% following EVAR and 9.5% following OSR within 12 months (p = 0.719), and 11.5% following EVAR and 10.8% following OSR within 15 months (p = 0.785) were reported. ConclusionAdministrative healthcare data as an addition to the DSAA is potentially beneficial to evaluate mid-term reinterventions following intact AAA repair without increasing the registration burden for clinicians. Further validation is necessary before reliable implementation of this tool is warranted.

Nationwide Outcomes of Octogenarians Following Open or Endovascular Management After Ruptured Abdominal Aortic Aneurysms

Purpose: Octogenarians are known to have less-favorable outcomes following ruptured abdominal aortic aneurysm (rAAA) repair compared with their younger counterparts. Accurate information regarding perioperative outcomes following rAAA-repair is important to evaluate current treatment practice. The aim of this study was to evaluate perioperative outcomes of octogenarians and to identify factors associated with mortality and major complications after open surgical repair (OSR) or endovascular aneurysm repair (EVAR) of a rAAA using nationwide, real-world, contemporary data. Methods: All patients that underwent EVAR or OSR of an infrarenal or juxtarenal rAAA between January 1, 2013, and December 31, 2018, were prospectively registered in the Dutch Surgical Aneurysm Audit (DSAA) and included in this study. The primary outcome was the comparison of perioperative outcomes of octogenarians versus non-octogenarians, including adjustment for confounders. Secondary outcomes were the identification of factors associated with mortality and major complications in octogenarians. Results: The study included 2879 patients, of which 1146 were treated by EVAR (382 octogenarians, 33%) and 1733 were treated by OSR (410 octogenarians, 24%). Perioperative mortality of octogenarians following EVAR was 37.2% versus 14.8% in non-octogenarians (adjusted OR=2.9, 95% CI=2.8–3.0) and 50.0% versus 29.4% following OSR (adjusted OR=2.2, 95% CI=2.2–2.3). Major complication rates of octogenarians were 55.4% versus 31.8% in non-octogenarians following EVAR (OR=2.7, 95% CI=2.1–3.4), and 68% versus 49% following OSR (OR=2.2, 95% CI=1.8–2.8). Following EVAR, 30.6% of the octogenarians had an uncomplicated perioperative course (UPC) versus 49.5% in non-octogenarians (OR=0.5, 95% CI=0.4–0.6), while following OSR, UPC rates were 20.7% in octogenarians versus 32.6% in non-octogenarians (OR=0.5, 95% CI=0.4–0.7). Cardiac or pulmonary comorbidity and loss of consciousness were associated with mortality and major complications in octogenarians. Interestingly, female octogenarians had lower mortality rates following EVAR than male octogenarians (adjusted OR=0.7, 95% CI=0.6–0.8). Conclusion: Based on this nationwide study with real-world registry data, mortality rates of octogenarians following ruptured AAA-repair were high, especially after OSR. However, a substantial proportion of these octogenarians following OSR and EVAR had an uneventful recovery. Known preoperative factors do influence perioperative outcomes and reflect current treatment practice.

Association of Hospital Volume with Perioperative Mortality of Endovascular Repair of Complex Aortic Aneurysms: A Nationwide Cohort Study

A review of the Dutch Surgical Aneurysm Audit between January 2016 and January 2020. Of 694 patients who underwent complex aortic aneurysm repair with fenestrated (n = 539) or branched (n = 155) endografts, the postoperative complication rates were 30% and 49%, respectively. The highest volume hospitals treated significantly more complex patients. Perioperative mortality of complex endovascular aneurysm repair was significantly higher in hospitals with an annual volume of fewer than 9 cases (9%) compared with hospitals with an annual volume of 13 or more cases (3%). This nationwide registry shows that high-volume complex endovascular aneurysm repair centers demonstrate lower mortality rates.

Mortality following elective abdominal aortic aneurysm repair in women.

Previous studies have focused on patient-related risk factors to explain the higher mortality risk in women undergoing elective abdominal aortic aneurysm (AAA) repair. The aim of this study was to evaluate whether hospital-related factors influence outcomes following AAA repair in women. Patients undergoing elective AAA repair in 61 hospitals in the Netherlands were identified from the Dutch Surgical Aneurysm Audit registry (2013-2018). A mixed-effects logistic regression analysis was conducted to assess the effect of sex on in-hospital and/or 30-day mortality. This analysis accounted for possible correlation of outcomes among patients who were treated in the same hospital, by adding a hospital-specific random effect to the statistical model. The analysis adjusted for patient-related risk factors and hospital volume of open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Some 12 034 patients were included in the analysis. The mortality rate was higher in women than among men: 53 of 1780 (3.0 per cent) versus 152 of 10 254 (1.5 per cent) respectively. Female sex was significantly associated with mortality after correction for patient- and hospital-related factors (odds ratio 1.68, 95 per cent c.i. 1.20 to 2.37). OSR volume was associated with lower mortality (OR 0.91 (0.85 to 0.95) per 10-procedure increase) whereas no such relationship was identified with EVAR volume (OR 1.03 (1.01 to 1.05) per 10-procedure increase). Women are at higher risk of death after abdominal aortic aneurysm repair irrespective of patient- and hospital-related factors.

Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study

The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time.

Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study

<h3>Objective</h3> The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time. <h3>Methods</h3> Patients who underwent primary repair of an iAAA by standard endovascular (EVAR) or open surgical repair (OSR) between 2014 and 2019 were selected from the DSAA for inclusion. The primary outcome was peri-operative mortality trend per year, stratified by OSR and EVAR. Secondary outcomes were trends per year in major complications, textbook outcome (TbO), and characteristics of treated patients. The trends per year were evaluated and reported in odds ratios per year. <h3>Results</h3> In this study, 11 624 patients (74.8%) underwent EVAR and 3 908 patients (25.2%) underwent OSR. For EVAR, after adjustment for confounding factors, there was no improvement in peri-operative mortality (aOR [adjusted odds ratio] 1.06, 95% CI 0.94 – 1.20), while major complications decreased (2014: 10.1%, 2019: 7.0%; aOR 0.91, 95% CI 0.88 – 0.95) and the TbO rate increased (2014: 68.1%, 2019: 80.9%; aOR 1.13, 95% CI 1.10 – 1.16). For OSR, the peri-operative mortality decreased (2014: 6.1%, 2019: 4.6%; aOR 0.89, 95% CI 0.82 – 0.98), as well as major complications (2014: 28.6%, 2019: 23.3%; aOR 0.95, 95% CI 0.91 – 0.99). Furthermore, the proportion of TbO increased (2014: 49.1%, 2019: 58.3%; aOR 1.05, 95% CI 1.01 – 1.10). In both the EVAR and OSR group, the proportion of patients with cardiac comorbidity increased. <h3>Conclusion</h3> Since the establishment of this nationwide quality improvement initiative (DSAA), all outcomes of iAAA repair following EVAR and OSR have improved, except for peri-operative mortality following EVAR which remained unchanged.

Results from a nationwide prospective registry on open surgical or endovascular repair of juxtarenal abdominal aortic aneurysms.

Juxtarenal abdominal aortic aneurysms (JRAAAs) can be treated either with open surgical repair (OSR) including suprarenal clamping or by complex endovascular aneurysm repair (cEVAR). In this study, we present the comparison between the short-term mortality and complications of the elective JRAAA treatment modalities from a national database reflecting daily practice in The Netherlands. All patients undergoing elective JRAAA open repair or cEVAR (fenestrated EVAR or chimney EVAR) between January 2016 and December 2018 registered in the Dutch Surgical Aneurysm Audit (DSAA) were eligible for inclusion. Descriptive perioperative variables and outcomes were compared between patients treated with open surgery or endovascularly. Adjusted odds ratios for short-term outcomes were calculated by logistic regression analysis. In all, 455 primary treated patients with JRAAAs could be included (258 OSR, 197 cEVAR). Younger patients and female patients were treated more often with OSR vs cEVAR (72± 6.1 vs 76± 6.0; P< .001 and 22% vs 15%; P= .047, respectively). Patients treated with OSR had significantly more major and minor complications as well as a higher chance of early mortality (OSR vs cEVAR, 45% vs 21%; P< .001; 34% vs 23%; P= .011; and 6.6% vs 2.5%; P= .046, respectively). After logistic regression with adjustment for confounders, patients who were treated with OSR showed an odds ratio of 3.64 (95% confidence interval [CI], 2.25-5.89; P< .001) for major complications compared with patients treated with cEVAR, and for minor complications, the odds ratios were 2.17 (95% CI, 1.34-3.53; P= .002) higher. For early mortality, the odds ratios were 3.79 (95% CI, 1.26-11.34; P= .017) higher after OSR compared with cEVAR. In this study, after primary elective OSR for JRAAA, the odds for major complications, minor complications, and short-term mortality were significantly higher compared with cEVAR.

Identifying Women at High Risk of 90 Day Death after Elective Open Abdominal Aortic Aneurysm Repair: A Multicentre Case Control Study

The aim of this study was to identify risk factors for 90 day death after elective open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) in women. This was a multicentre case control study. The nationwide Dutch Surgical Aneurysm Audit registry (2013-2019) was solely used to identify women who underwent elective OSR as eligible patients. Data for this study were subsequently collected from the patients' medical files. Women with AAA were included and those who died (cases) were compared with those who survived (controls) 90 days after surgery. Inflammatory, mycotic, or symptomatic or ruptured AAA were excluded. The association between pre- and peri-operative risk factors and death was assessed by logistic regression analysis in the whole sample and after matching cases to controls of the same age at the time of repair. Mesenteric artery patency was also assessed on pre-operative computed tomography and used in the analysis. In total, 266 patients (30 cases and 236 controls) from 21 hospitals were included. Cases were older (median [interquartile range; IQR] 75 years [71, 78.3] vs. 71 years [66, 77]; p= .002) and more often had symptomatic peripheral arterial disease (PAD) (14/29 [48%] vs. 49/227 [22%]; p= .002). Intra-operative blood loss (median [IQR] 1.6 L [1.1, 3.0] vs. 1.2 L [0.7, 1.8]), acute myocardial infarction (AMI) (10/30 [33%] vs. 8/236 [3%]), renal failure (17/30 [57%] vs. 33/236 [14%]), and bowel ischaemia (BI) (17/29 [59%] vs. 12/236 [5%]) were more prevalent among cases. Older age (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.03-1.19) and PAD (OR 3.91, 95% CI 1.57-9.74) were associated with death. Multivariable analysis demonstrated that, after adjustment for age, AMI (OR 9.34, 95% CI 1.66-52.4) and BI (OR 35.6, 95% CI 3.41-370) were associated with death. Superior mesenteric artery stenosis of >70% had a clinically relevant association with BI (OR 5.23, 95% CI 1.43-19.13; p= .012). Age, symptomatic PAD, AMI, and BI were risk factors for death after elective OSR in women. The association between a >70% SMA stenosis and BI may call for action in selected cases.

Association of Hospital Volume with Perioperative Mortality of Endovascular Repair of Complex Aortic Aneurysms: A Nationwide Cohort Study.

We evaluate nationwide perioperative outcomes of complex EVAR and assess the volume-outcome association of complex EVAR. Endovascular treatment with fenestrated (FEVAR) or branched (BEVAR) endografts is progressively used for excluding complex aortic aneurysms (complex AAs). It is unclear if a volume-outcome association exists in endovascular treatment of complex AAs (complex EVAR). All patients prospectively registered in the Dutch Surgical Aneurysm Audit who underwent complex EVAR (FEVAR or BEVAR) between January 2016 and January 2020 were included. The effect of annual hospital volume on perioperative mortality was examined using multivariable logistic regression analyses. Patients were stratified into quartiles based on annual hospital volume to determine hospital volume categories. We included 694 patients (539 FEVAR patients, 155 BEVAR patients). Perioperative mortality following FEVAR was 4.5% and 5.2% following BEVAR. Postoperative complication rates were 30.1% and 48.7%, respectively. The first quartile hospitals performed <9 procedures/yr; second, third, and fourth quartile hospitals performed 9-12, 13-22, and ≥23 procedures/yr. The highest volume hospitals treated the significantly more complex patients. Perioperative mortality of complex EVAR was 9.1% in hospitals with a volume of < 9, and 2.5% in hospitals with a volume of ≥13 (P = 0.008). After adjustment for confounders, an annual volume of ≥13 was associated with less perioperative mortality compared to hospitals with a volume of < 9. Data from this nationwide mandatory quality registry shows a significant effect of hospital volume on perioperative mortality following complex EVAR, with high volume complex EVAR centers demonstrating lower mortality rates.

Short-term outcomes of open surgical abdominal aortic aneurysm repair from the Dutch Surgical Aneurysm Audit.

BackgroundThe sharp decrease in open surgical repair (OSR) for abdominal aortic aneurysm (AAA) has raised concerns about contemporary postoperative outcomes. The study was designed to analyse the impact of complications on clinical outcomes within 30 days following OSR.MethodsPatients who underwent OSR for intact AAA registered prospectively between 2016 and 2019 in the Dutch Surgical Aneurysm Audit were included. Complications and outcomes (death, secondary interventions, prolonged hospitalization) were evaluated. The adjusted relative risk (aRr) and 95 per cent confidence intervals were computed using Poisson regression. Subsequently, the population-attributable fraction (PAF) was calculated. The PAF reflects the expected percentage reduction of an outcome if a complication were to be completely prevented.ResultsA total of 1657 patients were analysed. Bowel ischaemia and renal complications had the largest impact on death (aRr 12·44 (95 per cent c.i. 7·95 to 19·84) at PAF 20 (95 per cent c.i. 8·4 to 31·5) per cent and aRr 5·07 (95 per cent c.i. 3·18 to 8.07) at PAF 14 (95 per cent c.i. 0·7 to 27·0) per cent, respectively). Arterial occlusion had the greatest impact on secondary interventions (aRr 11·28 (95 per cent c.i. 8·90 to 14·30) at PAF 21 (95 per cent c.i. 14·7 to 28·1) per cent), and pneumonia (aRr 2·52 (95 per cent c.i. 2·04 to 3·10) at PAF 13 (95 per cent c.i. 8·3 to 17·8) per cent) on prolonged hospitalization. Small effects were observed on outcomes for other complications.ConclusionThe greatest clinical impact following OSR can be made by focusing on measures to reduce the occurrence of bowel ischaemia, arterial occlusion and pneumonia.

Outcomes in Octogenarians and the Effect of Comorbidities After Intact Abdominal Aortic Aneurysm Repair in the Netherlands: A Nationwide Cohort Study

Age is an independent risk factor for mortality after both elective open surgical repair (OSR) and endovascular aneurysm repair (EVAR). As a result of an ageing population, and the less invasive nature of EVAR, the number of patients over 80 years (octogenarians) being treated is increasing. The mortality and morbidity following aneurysm surgery are increased for octogenarians. However, the mortality for octogenarians who have either low or high peri-operative risks remains unclear. The aim of this study was to provide peri-operative outcomes of octogenarians vs. non-octogenarians after OSR and EVAR for intact aneurysms, including separate subanalyses for elective and urgent intact repair, based on a nationwide cohort. Furthermore, the influence of comorbidities on peri-operative mortality was examined. All patients registered in the Dutch Surgical Aneurysm Audit (DSAA) undergoing intact AAA repair between 2013 and 2018, were included. Patient characteristics and peri-operative outcomes (peri-operative mortality, and major complications) of octogenarians vs. non-octogenarians for both OSR and EVAR were compared using descriptive statistics. Multivariable logistic regression analyses were used to examine whether age and the presence of cardiac, pulmonary, or renal comorbidities were associated with mortality. This study included 12 054 EVAR patients (3 015 octogenarians), and 3 815 OSR patients (425 octogenarians). Octogenarians in both the EVAR and OSR treatment groups were more often female and had more comorbidities. In both treatment groups, octogenarians had significantly higher mortality rates following intact repair as well as higher major complication rates. Mortality rates of octogenarians were 1.9% after EVAR and 11.8% after OSR. Age ≥ 80 and presence of cardiac, pulmonary, and renal comorbidities were associated with mortality after EVAR and OSR. Because of the high peri-operative mortality rates of octogenarians, awareness of the presence of comorbidities is essential in the decision making process before offering aneurysm repair to this cohort, especially when OSR is considered.

Effects of hospital preference for endovascular repair on postoperative mortality after elective abdominal aortic aneurysm repair: analysis of the Dutch Surgical Aneurysm Audit.

BackgroundIncreased use of endovascular aneurysm repair (EVAR) and reduced open surgical repair (OSR), has decreased postoperative mortality after elective repair of abdominal aortic aneurysms (AAAs). The choice between EVAR or OSR depends on aneurysm anatomy, and the experience and preference of the vascular surgeon, and therefore differs between hospitals. The aim of this study was to investigate the current mortality risk difference (RD) between EVAR and OSR, and the effect of hospital preference for EVAR on overall mortality.MethodsPrimary elective infrarenal or juxtarenal aneurysm repairs registered in the Dutch Surgical Aneurysm Audit (2013–2017) were analysed. First, mortality in hospitals with a higher preference for EVAR (high-EVAR group) was compared with that in hospitals with a lower EVAR preference (low-EVAR group), divided by the median percentage of EVAR. Second, the mortality RD between EVAR and OSR was determined by unadjusted and adjusted linear regression and propensity-score (PS) analysis and then by instrumental-variable (IV) analysis, adjusting for unobserved confounders; percentage EVAR by hospital was used as the IV.ResultsA total of 11 997 patients were included. The median hospital rate of EVAR was 76.6 per cent. The overall mortality RD between high- and low-EVAR hospitals was 0.1 (95 per cent −0.5 to 0.4) per cent. The OSR mortality rate was significantly higher among high-EVAR hospitals than low-EVAR hospitals: 7.3 versus 4.0 per cent (RD 3.3 (1.4 to 5.3) per cent). The EVAR mortality rate was also higher in high-EVAR hospitals: 0.9 versus 0.7 per cent (RD 0.2 (−0.0 to 0.6) per cent). The RD following unadjusted, adjusted, and PS analysis was 4.2 (3.7 to 4.8), 4.4 (3.8 to 5.0), and 4.7 (4.1 to 5.3) per cent in favour of EVAR over OSR. However, the RD after IV analysis was not significant: 1.3 (−0.9 to 3.6) per cent.ConclusionEven though EVAR has a lower mortality rate than OSR, the overall effect is offset by the high mortality rate after OSR in hospitals with a strong focus on EVAR.

Outcomes in Octogenarians and the Effect of Comorbidities After Intact Abdominal Aortic Aneurysm Repair in the Netherlands: A Nationwide Cohort Study

Age is an independent risk factor for mortality after both elective open surgical repair (OSR) and endovascular aneurysm repair (EVAR). As a result of an ageing population, and the less invasive nature of EVAR, the number of patients over 80 years (octogenarians) being treated is increasing. The mortality and morbidity following aneurysm surgery are increased for octogenarians. However, the mortality for octogenarians who have either low or high peri-operative risks remains unclear. The aim of this study was to provide peri-operative outcomes of octogenarians vs. non-octogenarians after OSR and EVAR for intact aneurysms, including separate subanalyses for elective and urgent intact repair, based on a nationwide cohort. Furthermore, the influence of comorbidities on peri-operative mortality was examined. All patients registered in the Dutch Surgical Aneurysm Audit (DSAA) undergoing intact AAA repair between 2013 and 2018, were included. Patient characteristics and peri-operative outcomes (peri-operative mortality, and major complications) of octogenarians vs. non-octogenarians for both OSR and EVAR were compared using descriptive statistics. Multivariable logistic regression analyses were used to examine whether age and the presence of cardiac, pulmonary, or renal comorbidities were associated with mortality. This study included 12 054 EVAR patients (3 015 octogenarians), and 3 815 OSR patients (425 octogenarians). Octogenarians in both the EVAR and OSR treatment groups were more often female and had more comorbidities. In both treatment groups, octogenarians had significantly higher mortality rates following intact repair as well as higher major complication rates. Mortality rates of octogenarians were 1.9% after EVAR and 11.8% after OSR. Age ≥ 80 and presence of cardiac, pulmonary, and renal comorbidities were associated with mortality after EVAR and OSR. Because of the high peri-operative mortality rates of octogenarians, awareness of the presence of comorbidities is essential in the decision making process before offering aneurysm repair to this cohort, especially when OSR is considered.

Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

Objective The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Methods This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests. Results The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38–50) mm and 68 (IQR 58–85) mm, respectively. Mortality was 1.3% (95% CI 0.7–2.4) after eIAA repair and 25.5% (95% CI 18.0–34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively). Conclusion In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Patients with a Ruptured Abdominal Aortic Aneurysm Are Better Informed in Hospitals with an “EVAR-preferred” Strategy: An Instrumental Variable Analysis of the Dutch Surgical Aneurysm Audit

While several observational studies suggested a lower postoperative mortality after minimal invasive endovascular aneurysm repair (EVAR) in patients with a ruptured abdominal aortic aneurysm (RAAA) compared to conventional open surgical repair (OSR), landmark randomized controlled trials have not been able to prove the superiority of EVAR over OSR. Randomized controlled trials contain a selected, homogeneous population, influencing external validity. Observational studies are biased and adjustment of confounders can be incomplete. Instrumental variable (IV) analysis (pseudorandomization) may help to answer the question if patients with an RAAA have lower postoperative mortality when undergoing EVAR compared to OSR. This is an observational study including all patients with an RAAA, registered in the Dutch Surgical Aneurysm Audit between 2013 and 2017. The risk difference (RD) in postoperative mortality (30 days/in-hospital) between patients undergoing EVAR and OSR was estimated, in which adjustment for confounding was performed in 3 ways: linear model adjusted for observed confounders, propensity score model (multivariable logistic regression analysis), and IV analysis (two-stage least square regression), adjusting for observed and unobserved confounders, with the variation in percentage of EVAR per hospital as the IV instrument. 2419 patients with an RAAA (1489 OSR and 930 EVAR) were included. Unadjusted postoperative mortality was 34.9% after OSR and 22.6% after EVAR (RD 12.3%, 95% CI 8.5-16%). The RD adjusted for observed confounders using linear regression analysis and propensity score analysis was, respectively, 12.3% (95% CI 9.6-16.7%) and 13.2% (95%CI 9.3-17.1%) in favor of EVAR. Using IV analysis, adjusting for observed and unobserved confounders, RD was 8.9% (95% CI -1.1-18.9%) in favor of EVAR. Adjusting for observed confounders, patients with an RAAA undergoing EVAR had a significant better survival than OSR in a consecutive large cohort. Adjustment for unobserved confounders resulted in a clinical relevant RD. An "EVAR preference strategy" in patients with an RAAA could result in lower postoperative mortality.

National Numbers of Secondary Aortic Reinterventions after Primary Abdominal Aortic Aneurysm Surgery from the Dutch Surgical Aneurysm Audit

Long-term secondary aortic reinterventions (SARs) can be a sign of (lack of) effectiveness of abdominal aortic aneurysm (AAA) surgery. This study provides insight into the national number of SARs after primary AAA repair by endovascular aneurysm repair (EVAR) or by open surgical repair in the Netherlands. Observational study included all patients undergoing SAR between 2016 and 2017, registered in the compulsory Dutch Surgical Aneurysm Audit (DSAA). The DSAA started in 2013, SARs are registered from 2016. Characteristics of SAR and postoperative outcomes (mortality/complications) were analyzed, stratified by urgency of SAR. Data of SARs were merged with data of their preceded primary AAA repair, registered in the DSAA after January 2013. In these patients undergoing SAR, treatment characteristics of the preceded primary AAA repair were additionally described, with focus on differences between stent grafts. Between 2016 and 2017, 691 patients underwent SAR, this concerned 9.3% of all AAA procedures (infrarenal/juxtarenal/suprarenal) in the Netherlands (77% elective/11% acute symptomatic/12% ruptured). Endoleak (60%) was the most frequent indication for SAR. SARs were performed with EVAR in 66%. Postoperative mortalities after SAR were 3.4%, 11%, and 29% in elective, acute symptomatic, and ruptured patients, respectively. In 26% (n=181) of the patients undergoing SAR their primary AAA repair was performed after January 2013 and data of primary and SAR procedures could be merged. In 93% (n=136), primary AAA repair was EVAR. Endografts primarily used were nitinol/polyester (62%), nitinol/polytetrafluoroethylene (8%), endovascular sealing (21%), and others (9%), compared with their national market share of 76% (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.38-0.71), 15% (OR, 0.50; CI, 0.29-0.89), 4.9% (OR, 5.04; CI, 3.44-7.38), and 4.1% (OR, 2.81; CI, 1.66-4.74), respectively. In the Netherlands, about one-tenth of the annual AAA procedures concerns an SAR. A quarter of this cohort had an SAR within 1-5years after their primary AAA repair. Most SARs followed after primary EVAR procedures, in which an overrepresentation of endovascular sealing grafts was seen. Postoperative mortality after SAR is comparable with primary AAA repair.

Editor's Choice – Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameterexceeds3.5cm, as opposed to 3.0cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR). This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests. The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively). In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Variation in Surgical Treatment of Abdominal Aortic Aneurysms With Small Aortic Diameters in the Netherlands.

To evaluate reasons to deviate from aneurysm diameter thresholds, and focus on the difference in how Dutch vascular surgical units (VSUs) perceive their deviation and their actual deviation. Guidelines recommend surgical treatment for asymptomatic abdominal aortic aneurysms (AAAs) with a diameter of at least 55 mm for men and 50 mm for women. We evaluate reasons to deviate from these guidelines, and focus on the difference in how Dutch vascular surgical units (VSUs) perceive their deviation and their actual deviation. All patients undergoing elective AAA repair between 2013 and 2016 registered in the Dutch Surgical Aneurysm Audit (DSAA) were included. Surgery at diameters of <55 mm for men and <50 mm for women were considered guideline deviations. National deviation and hospital variation in deviation were evaluated over time. Questionnaires were distributed among all Dutch VSUs, inquiring for acceptable reasons for guideline deviation. VSUs were asked to estimate the guideline deviation percentage in their hospital which was then compared with their DSAA percentage. In all, 9039 patients were included. In 15%, we found guideline deviation, varying from 2% to 40% between VSUs. Over time, 21 VSUs were identified with a lower percentage of deviation than the national mean each year and 8 VSUs with a higher percentage. 44/60 VSUs completed the questionnaire. Most commonly reported reasons to deviate were concomitant large iliac diameter (91%) and saccular aneurysm (82%). The majority of the VSUs (77%) estimated their guideline deviation to be <5%. Eleven VSUs (25%) estimated their deviation concordant with their DSAA percentage, but 75% of VSUs underestimated their deviation. Dutch VSUs regularly deviate from the guidelines regarding aneurysm diameter, with variation between VSUs. Consensus exists amongst VSUs on acceptable reasons for guideline deviations; however, the majority underestimates their actual deviation percentage.

Nationwide study of the treatment of mycotic abdominal aortic aneurysms comparing open and endovascular repair in The Netherlands

ObjectiveMycotic aneurysms of the abdominal aorta (MAAA) can be treated by open repair (OR) or endovascular aneurysm repair (EVAR). This nationwide study provides an overview of the situation of MAAA treatment in The Netherlands in 2016. MethodsA retrospective cohort study was conducted with all centers that registered aortic abdominal aneurysms in the Dutch Surgical Aneurysm Audit in 2016. Questionnaires on 1-year outcomes were sent to all centers that treated patients with MAAA. The primary aim was to determine 30-day and 1-year mortality and morbidity of OR- and EVAR-treated patients. Morbidity was determined by the need for reoperations and the number of readmissions to the hospital. ResultsTwenty-six MAAA were detected in the Dutch Surgical Aneurysm Audit database of 2016, resulting in an incidence of 0.7% of all registered abdominal aortic aneurysms. The 30-day mortality for OR and EVAR treated patients was 1 in 13 and 0 in 13, respectively. Major and minor reinterventions within 30 days were needed for two (one OR and one EVAR) and two (one OR and one EVAR) patients, respectively. Two patients (15.4%) in the OR group and one patient (7.7%) in the EVAR group were readmitted to hospital within 30 days. In total, 1-year outcomes of 23 patients were available. In the OR group, one patient (9.1%) died in the first postoperative year. There was one major reintervention (removal of endoprosthesis and spiralvein reconstruction) in the EVAR group. Two patients (18.2%) treated with OR and two (16.7%) treated with EVAR required a minor reintervention. In both groups, four patients (OR, 36.4%; EVAR, 33.3%) were readmitted to hospital within 1 year postoperatively. ConclusionsBoth OR- and EVAR-treated patients show acceptable clinical outcomes after 30 days and at the 1-year follow-up. Depending on the clinical course of the patient, EVAR may be considered in the management of this disease.

Saccular Abdominal Aortic Aneurysms: Patient Characteristics, Clinical Presentation, Treatment, and Outcomes in the Netherlands

Observational study of the Dutch Surgical Aneurysm Audit between January 2016 and December 2018. Of 7659 patients with abdominal aortic aneurysms (AAAs), 94% (7188) had fusiform and 6% (471) had saccular AAAs. Significantly more patients with saccular AAAs presented acutely with AAA maximum diameter of less than 5.5 cm (25% vs 8%) and <less than 4.5 cm (8% vs 1%) than did fusiform AAAs. Saccular AAAs present acutely at smaller diameters than fusiform AAAs. Saccular AAAs should be electively treated at smaller diameter (>4.5 cm) than fusiform AAAs (>5.5 cm).