The Relationship Between Aortic Aneurysm Surgery Volume and Peri-Operative Mortality in Australia

Editor's Choice - Vascular Registries Contributing to VASCUNET Collaborative Abdominal Aortic Aneurysm Outcome Projects: A Scoping Review

OBJECTIVE

Vascular surgery registries report on procedures and outcomes to promote patient safety and drive quality improvement. International registries have contributed significantly to the VASCUNET collaborative abdominal aortic aneurysm (AAA) outcome projects. This scoping review aimed to outline the national registries in vascular surgery that currently participate in the VASCUNET collaborative AAA projects.

METHODS

A scoping review of all published VASCUNET AAA studies and validation reports between 1997 and 2024 was undertaken. A survey was conducted among representatives of the international vascular registries contributing to VASCUNET collaborative AAA projects.

RESULTS

Currently, vascular registries from 10 countries (Australia, Denmark, Finland, Hungary, Iceland, New Zealand, Norway, Sweden, Switzerland, and the UK) contribute to the current VASCUNET collaborative AAA project, of which eight have national coverage. In the past, three countries (Germany, Malta, and Italy) have participated in previous VASCUNET AAA projects, and a further three countries (Serbia, Greece, and Portugal) have planned participation in future projects. External validity is high for all current registries, with most reporting rates of > 90%. The majority have internal validation processes to assess data accuracy. VASCUNET mediated validation has also been performed by the consortium for five countries to date (Hungary, Sweden, Denmark, Malta, and Switzerland), for which a high degree of external and internal validity was identified. Most registries have established mechanisms for data linkage with national administrative datasets or insurance claims datasets and contribute to quality improvement through regular reporting to participating centres.

CONCLUSION

National vascular registries from nations participating in the VASCUNET collaborative AAA projects are largely comprehensive, with high case ascertainment rates and good quality data with internal quality assurance. This provides a template for new registries wishing to join the VASCUNET collaboration and a benchmark for future research.

Hospital Volume of Elective Abdominal Aortic Aneurysm Repair as a Predictor of Mortality After Ruptured Abdominal Aortic Aneurysm Repair

OBJECTIVE

Registry data suggest that centralising abdominal aortic aneurysm (AAA) surgery decreases the mortality rate after AAA repair. However, the impact of higher elective volumes on ruptured AAA (rAAA) repair associated mortality rates remains uncertain. This study aimed to examine associations between intact AAA (iAAA) repair volume and post-operative rAAA death.

METHODS

Using data from official national registries between 2015 - 2019, all iAAA and rAAA repairs were separately analysed across 10 public hospitals. The following were assessed: 30 day and 12 month mortality rate following open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Associations between the 5 year hospital iAAA repair volumes (organised into tertiles) and rAAA associated mortality rate were analysed, regardless of treatment modality. Receiver operating characteristic (ROC) curves were generated to identify iAAA volume thresholds for decreasing the rAAA mortality rate. Subanalysis by treatment type was conducted. Threshold analysis was repeated with the Markov chain Monte Carlo (MCMC) procedure to confirm the findings.

RESULTS

A total of 1 599 iAAAs (80.2% EVAR, 19.8% OSR) and 196 rAAAs (66.3% EVAR, 33.7% OSR) repairs were analysed. The median and interquartile range of the volume/hospital/year for all iAAA repairs were 39.2 (31.2, 47.4). The top volume iAAA tertile exhibited lower rAAA associated 30 day (odds ratio [OR] 0.374; p = .007) and 12 month (OR 0.264; p < .001) mortality rates. The ROC analysis revealed a threshold of 40 iAAA repairs/hospital/year (EVAR + OSR) for a reduced rAAA mortality rate. Middle volume hospitals for open iAAA repair had reduced 30 day (OR 0.267; p = .033) and 12 month (OR 0.223; p = .020) mortality rates, with a threshold of five OSR procedures/year. The MCMC procedure found similar thresholds. No significant association was found between elective EVAR volumes and ruptured EVAR mortality.

CONCLUSION

Higher iAAA repair volumes correlated with a lower rAAA mortality rate, particularly for OSR. The recommended iAAA repair threshold is 40 procedures/year and five procedures/year for OSR. These findings support high elective volumes for improving the rAAA mortality rate, especially for OSR.

Long-Term Outcomes Following Elective Repair of Intact Abdominal Aortic Aneurysms: A Comparison Between Open Surgical and Endovascular Repair Using Linked Administrative and Clinical Registry Data

OBJECTIVE

Compare long-term mortality, secondary intervention and secondary rupture following elective endovascular aneurysm repair (EVAR) and open surgical repair (OSR).

BACKGROUND

EVAR has surpassed OSR as the most common procedure used to repair abdominal aortic aneurysm (AAA), but evidence regarding long-term outcomes is inconclusive.

METHODS

We included patients in linked clinical registry and administrative data undergoing EVAR or OSR for intact AAA between January 2010 and June 2019. We used an inverse probability of treatment-weighted survival analysis to compare all-cause mortality, cause-specific mortality, secondary interventions and secondary rupture, and evaluate the impact of secondary interventions and secondary rupture on all-cause mortality.

RESULTS

The study included 3460 EVAR and 427 OSR patients. Compared to OSR, the EVAR all-cause mortality rate was lower in the first 30 days [adjusted hazard ratio (HR) = 0.22, 95% confidence interval (CI) 0.140.33], but higher between 1 and 4 years (HR = 1.29, 95% CI 1.12-1.48) and after 4years (HR = 1.41, 95% CI 1.23-1.63). Secondary intervention rates were higher over the first 30 days (HR = 2.26, 95% CI 1.11-4.59), but lower between 1 and 4years (HR = 0.59, 95% CI 0.48-0.74). Secondary aortic intervention rates were higher across the entire follow-up period (HR = 2.52, 95% CI 2.06-3.07). Secondary rupture rates did not differ significantly (HR = 1.06, 95% CI 0.73-1.55). All-cause mortality beyond 1 year remained significantly higher for EVAR after adjusting for any secondary interventions, or secendary rupture.

CONCLUSIONS

EVAR has an early survival benefit compared to OSR. However, elevated long-term mortality and higher rates of secondary aortic interventions and subsequent aneurysm repair suggest that EVAR may be a less durable method of aortic aneurysm exclusion.

Editor's Choice - Comparison of Outcomes for Major Contemporary Endograft Devices Used for Endovascular Repair of Intact Abdominal Aortic Aneurysms

OBJECTIVE

To compare rates of mortality, rupture, and secondary intervention following endovascular repair (EVAR) of intact abdominal aortic aneurysms (AAA) using contemporary endograft devices from three major manufacturers.

METHODS

This was a retrospective cohort study using linked clinical registry (Australasian Vascular Audit) and all payer administrative data. Patients undergoing EVAR for intact AAA between 2010 and 2019 in New South Wales, Australia were identified. Rates of all cause death, secondary rupture, and secondary intervention (subsequent aneurysm repair; other secondary aortic intervention) were compared for patients treated with Cook, Medtronic, and Gore standard devices. Inverse probability of treatment weighted proportional hazards and competing risk regression were used to adjust for patient, clinical, and aneurysm characteristics, using Cook as the referent device.

RESULTS

This study identified 2 874 eligible EVAR patients, with a median follow up of 4.1 (maximum 9.5) years. Mortality rates were similar for patients receiving different devices (ranging between 7.0 and 7.3 per 100 person years). There was no statistically significant difference between devices in secondary rupture rates, which ranged between 0.4 and 0.5 per 100 person years. Patients receiving Medtronic and Gore devices tended to have higher crude rates of subsequent aneurysm repair (1.5 per 100 person years) than patients receiving Cook devices (0.8 per 100 person years). This finding remained in the adjusted analysis, but was only statistically significant for Medtronic devices (HR 1.57, 95% CI 1.02 - 2.47; HR 1.73, 95% CI 0.94 - 3.18, respectively).

CONCLUSION

Major endograft devices have similar overall long term safety profiles. However, there may be differences in rates of secondary intervention for some devices. This may reflect endograft durability, or patient selection for different devices based on aneurysm anatomy. Continuous comparative assessments are needed to guide evidence for treatment decisions across the range of available devices.

Extent of aortic replacement and operative outcome in open proximal thoracic aortic aneurysm repair

Objectives

There are few data to delineate the risk differences among open aortic procedures. We aimed to investigate the influence of the procedural types on the outcomes of proximal thoracic aortic aneurysm repair.

Methods

Among 1900 patients who underwent aortic replacement in our institution between 2005 and 2019, 1132 patients with aortic aneurysm who underwent a graft replacement of proximal thoracic aorta were retrospectively reviewed. Patients were divided into 4 groups based on the extent of the aortic replacement: isolated ascending aortic replacement (n = 52); ascending aortic replacement with distal extension with hemiarch, partial arch, or total arch replacement (n = 126); ascending aortic replacement with proximal extension with aortic valve or root replacement (n = 620); and ascending aortic replacement with distal and proximal extension (n = 334). "Eventful recovery," defined as occurrence of any key complications, was used as the primary end point. Odds ratios for inability to achieve uneventful recovery in each procedure were calculated using ascending aortic replacement as a reference.

Results

Overall, in-hospital mortality and stroke occurred in 16 patients (1.4%) and 24 patients (2.1%). Eventful recovery was observed in 19.7% of patients: 11.5% in those with ascending aortic replacement, 36.5% in those with partial arch or total arch replacement, 16.6% in those with proximal extension with aortic valve or root replacement, and 20.4% in those with distal and proximal extension (P < .001). With ascending aortic replacement as the reference, a multivariable logistic regression revealed partial arch or total arch replacement (odds ratio, 10.0; 95% confidence interval, 1.8-189.5) was an independent risk factor of inability to achieve uneventful recovery.

Conclusions

Open proximal aneurysm repair in the contemporary era resulted in satisfactory in-hospital outcomes. Distal extension was associated with a higher risk for postoperative complications.

Midterm Results of Iliac Branch Devices in a Newly Established Aortic Center

The first-line treatment of common iliac artery aneurysms is endovascular repair. International guidelines recommend the preservation of the internal iliac artery, which is best achieved by the implantation of an iliac bifurcation device (IBD). Our aim was to evaluate the initial midterm results of IBDs in the leading vascular center of Hungary. In this single-center retrospective study, relevant clinical data and the results of the imaging examinations were collected and analyzed in all patients who underwent IBD implantation between December 2010 and July 2021. Thirty-five patients (31 males, mean age: 67.9 ± 8.5 years) underwent endovascular treatment with 37 IBD implantations. Technical success was achieved in 88.2% of the patients, with no perioperative mortality or open surgical conversion. One patient was lost during follow-up. Internal iliac artery occlusion was detected in three (8.8%) patients, and reintervention was performed in five (14.7%) patients. Primary patency of the internal iliac branch was 97.1% at 1 month, 93% at 2 months, and 89.0% at 5 years. The average follow-up time was 20.1 ± 26.2 months, during which two (5.9%) deaths occurred. Our initial experience with iliac branch devices was associated with a low complication rate and a favorable outcome, which confirms the midterm success of this intervention.

Low Volume Hospitals Are Not Associated with Inferior Outcomes After Thoracic Endovascular Aortic Repair

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) has been used increasingly to treat complex thoracic aortic pathology. This study aimed to assess hospital volume's impact on outcomes in patients undergoing TEVAR.

STUDY DESIGN

Patients undergoing TEVAR between January 2015 and December 2019 were identified in the Vascular Quality Initiative (VQI) database. The participating centers were grouped into either low-volume hospitals (LVH) or high-volume hospitals (HVH). We assessed the impact of hospital volume on 30-day mortality and major postoperative complications using a multivariable logistic regression analysis.

RESULTS

A total of 3,584 TEVAR patients (asymptomatic = 1,720; symptomatic/ruptured =1,864) were identified at 147 centers. The median average annual number of TEVAR cases at LVH and HVH was 6 and 17 cases, respectively. There was no significant difference in 30-day mortality between LVH and HVH (asymptomatic: 3.7% vs. 3.7%, p = 0.98; symptomatic/rupture: 9.3% vs. 7.3%, p = 0.13). After adjusting for multiple clinical and anatomical factors, being treated in LVH was not associated with increased 30-day mortality (asymptomatic: OR = 0.98, 95% CI: 0.52, 1.87, p = 0.96; symptomatic/rupture: OR = 1.15, 95%CI: 0.75, 1.77, p = 0.53) nor an increased risk of major complications, including renal, neurological, cardiac, pulmonary, and femoral artery access complication (all p > 0.05).

CONCLUSION

Using a large national database, we demonstrate that LVH is not associated with inferior TEVAR outcomes than HVH. The technical aspect of the procedure might play a role in the similarity of outcomes across the different institutional experiences.

A look to the future: Pandemic-induced digital technologies in vascular surgery

Like many areas of medicine, vascular surgery has been transformed by the COVID-19 (coronavirus disease 2019) pandemic. Public health precautions to minimize disease transmission have led to reduced attendance at hospitals and clinics in elective and emergency settings; fewer face-to-face and hands-on clinical interactions; and increased reliance on telemedicine, virtual attendance, investigations, and digital therapeutics. However, a “silver lining” to the COVID-19 pandemic may be the mainstream acceptance and acceleration of telemedicine, remote monitoring, digital health technology, and three-dimensional technologies, such as three-dimensional printing and virtual reality, by connecting health care providers to patients in a safe, reliable, and timely manner, and supplanting face-to-face surgical simulation and training. This review explores the impact of these changes in the delivery of vascular surgical care.

Association between Hospital Volume and Failure to Rescue after Open or Endovascular Repair of Intact Abdominal Aortic Aneurysms in the VASCUNET and International Consortium of Vascular Registries

OBJECTIVE

To investigate the association between hospital volume and failure to rescue (FtR), after open (OAR) and endovascular (EVAR) repair of intact abdominal aortic aneurysms (AAA) among centers participating in the VASCUNET and International Consortium of Vascular Registries (ICVR).

SUMMARY BACKGROUND DATA

FtR (i.e., in-hospital death following major complications) is a composite end-point representing the inability to treat complications effectively and prevent death.

METHODS

Using data from eight vascular registries, complication and mortality rates after intact AAA repair were examined (n = 60,273; EVAR-43,668; OAR-16,605). A restricted analysis using pooled data from four countries (Australia, Hungary, New Zealand, USA) reporting data on all postoperative complications (bleeding, stroke, cardiac, respiratory, renal, colonic ischemia) was performed to identify risk-adjusted association between hospital volume and FtR.

RESULTS

The most frequently reported complications were cardiac (EVAR-3.0%, OAR-8.9%) and respiratory (EVAR-1.0%, OAR-5.7%). In adjusted analysis, 4.3% of EVARs and 18.5% of OARs had at least one complication. The overall FtR rate was 10.3% after EVAR and 15.7% after OAR. Subjects treated in the highest volume centers(Q4) had 46% and 80% lower odds of FtR after EVAR (OR = 0.54; 95%CI = 0.34-0.87;p = 0.04) and OAR (OR = 0.22; 95%CI = 0.11-0.44;p < 0.001) when compared to lowest volume centers(Q1), respectively. Colonic ischemia had the highest risk of FtR for both procedures (adjusted predicted risks, EVAR: 27%, 95%CI 14%-45%; OAR: 30%, 95%CI 17%-46%).

CONCLUSIONS

In this multi-national dataset, FtR rate after intact AAA repair with EVAR and OAR is significantly associated with hospital volume. Hospitals in the top volume quartiles achieve the lowest mortality after a complication has occurred.

Open versus Endovascular Abdominal Aortic Aneurysm Repair in the Australian Private Sector Over Twenty Years

PURPOSE

Over the past two decades, the proliferation of endovascular surgery has changed the approach to abdominal aortic aneurysm (AAA) repair. In Australia, close to two-thirds of surgical procedures are performed in the private healthcare system. We aimed to describe the trends in AAA repair in the Australian private sector throughout the early 21st century.

MATERIALS AND METHODS

Medicare Benefits Schedule (MBS) statistics were accessed to determine the number of infrarenal open AAA repair (OAR) and endovascular AAA repair (EVAR) procedures performed between January 2000 and December 2019. Population data were extracted from the Australian Bureau of Statistics and used to calculate incidence per 100,000 population. Further analysis was performed according to age, gender, and state.

RESULTS

During the study period, 13,193 (67.0%) EVARs and 6504 (33.0%) OARs were performed in the Australian private sector. OARs fell from 70.5% (n=567) of AAA repairs in 2000 to 15.7% (n=237) in 2019, while EVARs rose from 29.5% (n=151) to 84.3% (n=808). The frequency of EVAR surpassed OAR in 2004. The overall incidence of AAA repair varied minimally over the time period (range: 4.9-6.5 per 100,000 adults per year). AAA repair was more common in males than females (9.7 vs 1.7 per 100,000 population) and more common in older age groups. There was a 4-fold increase in EVAR among males older than 85 years (12.8-57.4 per 100,000 population), the largest rise of any group. The overall EVAR:OAR ratio increased from 0.4 to 5.4. There were considerable state-based discrepancies.

CONCLUSION

The landscape of AAA repair in Australian private sector has drastically changed with a clear preference toward EVAR. EVAR saw increased use across all genders, age groups and states, despite stable rates of AAA surgery. Further research is necessary to compare our findings to national trends in the Australian public sector.

Predictors of 30-day readmission and resource utilization after thoracic endovascular aortic repair

OBJECTIVES

The introduction and expansion of thoracic endovascular aortic repair (TEVAR) have revolutionized the treatment of a variety of thoracic aortic diseases. We sought to evaluate the incidence, causes, predictors and costs associated with 30-day readmission after TEVAR in a nationally representative cohort.

METHODS

Adult patients undergoing isolated TEVAR were identified in the National Readmissions Database from 2010 to 2014. Hospital costs were estimated by converting individual hospital charge data adjusted to 2014 consumer price indices. Multivariable logistic regression was utilized to determine hospital- and patient-level factors associated with readmissions.

RESULTS

A total of 24 983 TEVARs were noted during the study period; the average age of the patients was 65 ± 16 years; 40% were women. The most common indication was an intact thoracic aneurysm (43.5%), followed by aortic dissection (30.5%). The average cost of the index admission was $63 644 ± $52 312; the average hospital stay was 11 ± 14 days; the index mortality rate was 6.7%. Readmissions within 30 days occurred in 17.4% of patients. Indications for readmission were varied; the most common aetiologies were cardiac (17.8%), infectious (16.0%) and pulmonary (12.1%). On multivariable analysis, the strongest predictor of readmission was the diagnosis, with a ruptured thoraco-abdominal aneurysm having the highest readmission burden (adjusted odds ratio 2.23, 1.17-4.24; P = 0.015). Notably, hospital volume did not predict index hospital length of stay, costs or 30-day readmissions (all P > 0.10).

CONCLUSIONS

Annual TEVAR volume was not associated with any of the outcomes assessed. Rather, indication for TEVAR was the strongest predictor for many outcomes. As TEVAR becomes increasingly utilized, a focus on cardiac and vascular diseases may reduce readmissions and improve quality of care.

Editor's Choice - Variation in Intact Abdominal Aortic Aneurysm Repair Outcomes by Country: Analysis of International Consortium of Vascular Registries 2010 - 2016

OBJECTIVE

Outcomes for intact abdominal aortic aneurysm (AAA) repair vary over time and by healthcare system, country, and surgeon. The aim of this study was to analyse peri-operative mortality for intact AAA repair in 11 countries over time and compare outcomes by gender, age, and geographical location.

METHODS

Prospective data on primary repair of intact AAA were collected from 11 countries through the International Consortium of Vascular Registries (ICVR) and analysed for two time periods, 2010 - 2013 and 2014 - 2016. The primary outcome was peri-operative mortality after endovascular aneurysm repair (EVAR) and open surgical repair (OSR). Multivariable logistic regression models were used to adjust for differences in patient characteristics.

RESULTS

A total of 103 715 patients were included. The percentage of patients undergoing EVAR increased from 63.6% to 71.2% (p < .001) over the study period. This proportion varied by country from 35% in Hungary to 81% in the United States. Overall peri-operative mortality decreased from 2.1% to 1.6 % (p < .001). Mortality also declined significantly over time for both OSR 4.2% to 3.6 % (p = .002) and EVAR 1.0% to 0.7% (p = .002). Mortality was significantly higher for female than male patients (3.0% vs. 1.6% p < .001). The percentage of patients > 80 years old undergoing AAA repair remained constant at 23.6% (p = .91). Peri-operative mortality was higher for patients > 80 years than for those < 80 years old (2.7% vs. 1.6% p < .001). Forty-six per cent (n = 275) of all EVAR deaths occurred in the over 80s.

CONCLUSION

The proportion of AAA repairs performed using EVAR has increased over time. Peri-operative mortality continues to decline for both OSR and EVAR. Outcomes however were significantly worse for both women and those aged over 80, so efforts should be focused on these patient groups to further reduce elective AAA mortality rates.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

Editor's Choice - Volume-Outcome Relationships in Elective Abdominal Aortic Aneurysm Surgery: Analysis of the UK Hospital Episodes Statistics Database for the Getting It Right First Time (GIRFT) Programme

OBJECTIVE

To investigate whether a volume-outcome relationship exists for elective abdominal aortic aneurysm (AAA) surgery conducted within the National Health Service (NHS) in England.

METHODS

This was an analysis of administrative data. Data were extracted from the Hospital Episodes Statistics database for England from April 2011 to March 2019 for all adult admissions for elective infrarenal AAA surgery. Data were extracted for the NHS trust and surgeon undertaking the procedure, the surgical technique used (open or endovascular), the financial year of admission, length of hospital and critical care stay during the procedure and subsequent emergency re-admissions (primary outcome) and deaths within 30 days. Multilevel modelling was used to adjust for hierarchy and confounding.

RESULTS

A dataset of 31 829 procedures (8867 open, 22 962 endovascular) was extracted. For open surgery, lower trust annual volume was associated with higher 30 day emergency re-admission rates and higher 30 day mortality. For open surgery, lower surgeon annual volume was associated with higher 30 day mortality and length of hospital stay greater than the median. For endovascular surgery, lower surgeon annual volume was associated with not having an overnight stay in critical care. None of the other volume-outcome relationships investigated was significant.

CONCLUSION

For elective infrarenal AAA surgery in the UK NHS, there was strong evidence of a volume-outcome relationship for open surgery. However, evidence for a volume-outcome relationship is dependent on the specific procedure undertaken and the outcome of interest.

The Relationship Between Operative Volume and Peri-operative Mortality After Non-elective Aortic Aneurysm Repair in Australia

OBJECTIVE

Hospital and surgeon operative caseload is thought to be associated with peri-operative mortality following the non-elective repair of aortic aneurysms; however, whether such an association exists within the Australian healthcare setting is unknown.

METHODS

The Australasian Vascular Audit was interrogated to identify patients undergoing non-elective (emergency [EMG] or semi-urgent [URG]) aortic aneurysm repair between 2010 and 2016, as well as their treating surgeon and hospital. Hierarchal logistic regression modelling was used to assess the impact of caseload on outcomes after both endovascular (EVAR) and open surgical repair (OSR).

RESULTS

Volume counts were determined from 14 262 patients (4 121 OSR and 10 141 EVAR). After exclusion of elective procedures and duplicates, 1 153 EVAR (570 EMG and 583 URG) and 1 245 OSR (946 EMG and 299 URG) non-elective cases remained for the analysis. Crude mortality was 24.0% following OSR (EMG 29.2%; URG 7.7%) and 7.5% following EVAR (EMG 12.6%; URG 2.4%). Univariable analysis demonstrated an association between OSR mortality and hospital volume (quintile [Q] 1: 25.3%, Q2: 27.8%, Q3: 23.9%, Q4: 27.0%, Q5: 16.2%; p = .030), but not surgeon (Q1: 25.2%, Q2: 27.4%, Q3: 26.0%, Q4: 21.4%, Q5: 19.5%, p = .32). Multivariable analysis confirmed this association (odds ratio (OR) [95% CI]; Q1 vs 5: 1.91 [1.13-3.21], Q2 vs. 5: 2.01[1.24-3.25], Q3 vs. 5: 1.41 [0.86-2.29], Q4 vs. 5: 1.92 [1.17-3.15]; p = .020). The difference was most pronounced in the EMG OSR group [Q1 - 3 vs. 4-5] (OR 1.63 [1.07-2.48]; p = .020). Mortality after EVAR was not associated with either hospital (Q1: 6.3%, Q2: 10%, Q3: 6.8%, Q4: 4.5%, Q5: 10%; p = .14) or surgeon volume (Q1: 9.3%, Q2: 5.7%, Q3: 8.1%, Q4: 7.0%, Q5: 7.3%; p = .67).

CONCLUSION

There is an inverse correlation between hospital volume and peri-operative mortality following EMG open repair of aortic aneurysm. These data support restructuring Australian pathways of care to direct suspected ruptured aneurysm to institutions that reach a minimum volume threshold.

Impact of Centralisation on Abdominal Aortic Aneurysm Repair Outcomes: Early Experience in Catalonia

OBJECTIVE

Several studies have revealed high volume centres have better outcomes in the treatment of abdominal aortic aneurysms (AAAs), thus supporting centralisation of this procedure into selected centres based on volume. To date however, the real benefit of centralisation of this pathology has not been well demonstrated. The aim of this study was to analyse the impact of centralisation in to high volume centres (defined as those performing more than 30 cases per year) on AAA treatment outcomes carried out in Catalonia (Spain).

METHODS

Data were collected from official national registries (HDMBD) for AAA treated by endovascular aneurysm repair (EVAR) or open repair (OR) over a nine year period. Two time periods were selected for comparison: before centralisation (2009-2014) and after complete centralisation (2015-2017). The primary objective was to determine short term mortality (in hospital and 30 day mortality) and length of stay (LOS) after intact AAA (iAAA) and ruptured AAA (rAAA) repair, before and after centralisation. Uni- and multivariable analyses were performed in order to identify independent outcomes predictors.

RESULTS

A total of 3 501 iAAAs, including 1 124 (32.1%) OR and 2377 (67.9%) EVAR, and 409 rAAAs, including 218 (53.3%) OR and 191 (46.7%) EVAR, were identified. After centralisation, there was a significant decrease in overall mortality in iAAA repair (4.7% vs. 2.0%, p < .001) and rAAA repair (53.1% vs. 41.9%, p = .028). Mortality reduction in iAAAs was significant for OR (8.7% vs. 3.6%, p = .005), but not for EVAR (2.2% vs. 1.5%, p = .25). Overall LOS decreased as well, mainly in iAAAs (9.49 ± 10.84 vs. 7.44 ± 12.23 days, p < .001), and in particular in elective EVAR (7.32 ± 7.73 vs. 6.00 ± 8.97 days, p < .001). Multivariable analysis was identified before the centralisation period as an independent predictor for both mortality (odds ratio 1.484, 95% CI 1.098-2.005, p = .010) and LOS (B coefficient 1.146, 95% CI 0.218-2.073, p = .016).

CONCLUSION

The implementation of a country based centralisation programme for AAA treatment led to a significant reduction in short term mortality, for both iAAA and rAAA, and mainly for elective OR. LOS also significantly decreased, mainly for elective EVAR. These results support the benefit of centralisation of AAA repair procedures.