Meta-Analysis and Systematic Review of the Relationship between Hospital Volume and Outcome Following Carotid Endarterectomy

Outcomes of redo vs primary carotid endarterectomy in the transcarotid artery revascularization era

OBJECTIVE

Outcomes following redo carotid endarterectomy (rCEA) have been shown to be worse than those after primary CEA (pCEA). Additional research has shown that outcomes are better with transcarotid artery revascularization (TCAR) for restenosis after CEA compared with rCEA and transfemoral carotid artery stenting; however, not all patients are eligible for TCAR or transfemoral carotid artery stenting. Given the increasing utilization of endovascular techniques, this study aims to evaluate changes in outcomes of rCEA vs pCEA before and after the approval of TCAR by the United States Food and Drug Administration in 2015.

METHODS

All patients between 2003 and 2023 who underwent CEA in the Vascular Quality Initiative were included and categorized as pCEA or rCEA. Cochrane-Armitage trend testing was used to examine trends in proportion of rCEA compared with pCEA, and the Mann-Kendall trend test was used for perioperative outcomes following rCEA overtime. Multivariable logistic regression was used to compare in-hospital stroke/death, stroke, death, and stroke/death/myocardial infarction following rCEA vs pCEA after stratifying patients into two cohorts: 2003 to 2015 and 2016 to 2023 (before and after introduction of TCAR). Analysis was also performed based on preoperative symptoms.

RESULTS

Of 198,150 patients undergoing CEA, 98.4% were pCEA and 1.6% were rCEA. During the study period, the proportion of rCEA in the Vascular Quality Initiative decreased from 2.3% to 1.0% as endovascular methods became more available (P < .001). Trend testing of individual outcomes showed an increase in the stroke/death rate following rCEA over time (P = .019) despite an improvement in the death rate (P = .009). From 2003 to 2015, patients undergoing rCEA had higher odds of stroke/death compared with pCEA (2.4% vs 1.2%; adjusted odds ratio [aOR], 1.81; 95% confidence interval [CI], 1.14-2.73; P = .007). Higher stroke/death rates after rCEA persisted only in asymptomatic patients (2.3% vs 1.1%; aOR, 2.03; 95% CI, 1.19-3.25; P = .006); however, there was no difference in symptomatic patients (3.0% vs 2.0%; aOR, 1.37; 95% CI, 0.51;3.01; P = .50). In the late period, rCEA had higher odds of stroke/death compared with pCEA (3.1% vs 1.3%; aOR, 2.45; 95% CI, 1.85-3.18; P < .001), and the association was seen in asymptomatic patients (1.9% vs 1.0%; aOR, 1.95; 95% CI, 1.29-2.82; P < .001) and symptomatic patients (6.3% vs 2.0%; aOR, 3.23; 95% CI, 2.17-4.64; P < .001).

CONCLUSIONS

The proportion of rCEAs done yearly in the United States has been decreasing as endovascular options became available. As the rate of rCEA has decreased, outcomes have been worsening, with an increasing stroke/death rate seen over time, driven primarily by worse outcomes in symptomatic patients. Stroke/death rates for asymptomatic patients fall within Society for Vascular Surgery guidelines, and so the choice between rCEA, CAS, or medical management should be made after shared decision-making between a patient and their surgeon. However, with an in-hospital stroke death rate of over 6% symptomatic patients should be selected very carefully, as some are less likely to benefit from rCEA.

Stroke risk management in carotid atherosclerotic disease: a clinical consensus statement of the ESC Council on Stroke and the ESC Working Group on Aorta and Peripheral Vascular Diseases

Carotid atherosclerotic disease continues to be an important cause of stroke, often disabling or fatal. Such strokes could be largely prevented through optimal medical therapy and carotid revascularization. Advancements in discovery research and imaging along with evidence from recent pharmacology and interventional clinical trials and registries and the progress in acute stroke management have markedly expanded the knowledge base for clinical decisions in carotid stenosis. Nevertheless, there is variability in carotid-related stroke prevention and management strategies across medical specialities. Optimal patient care can be achieved by (i) establishing a unified knowledge foundation and (ii) fostering multi-specialty collaborative guidelines. The emergent Neuro-Vascular Team concept, mirroring the multi-disciplinary Heart Team, embraces diverse specializations, tailors personalized, stratified medicine approaches to individual patient needs, and integrates innovative imaging and risk-assessment biomarkers. Proposed approach integrates collaboration of multiple specialists central to carotid artery stenosis management such as neurology, stroke medicine, cardiology, angiology, ophthalmology, vascular surgery, endovascular interventions, neuroradiology, and neurosurgery. Moreover, patient education regarding current treatment options, their risks and advantages, is pivotal, promoting patient's active role in clinical care decisions. This enables optimization of interventions ranging from lifestyle modification, carotid revascularization by stenting or endarterectomy, as well as pharmacological management including statins, novel lipid-lowering and antithrombotic strategies, and targeting inflammation and vascular dysfunction. This consensus document provides a harmonized multi-specialty approach to multi-morbidity prevention in carotid stenosis patients, based on comprehensive knowledge review, pinpointing research gaps in an evidence-based medicine approach. It aims to be a foundational tool for inter-disciplinary collaboration and prioritized patient-centric decision-making.

Analysis of Surgeon and Center Case Volume and Stroke or Death after Transcarotid Artery Revascularization

BACKGROUND

It has been suggested that the annual hospital volume of cases may affect the number of adverse events after carotid endarterectomy (CEA). We aim to study the associations between hospital as well as surgeon volume and the risk of stroke or death after transcarotid artery revascularization (TCAR).

STUDY DESIGN

Retrospective review of the Vascular Quality Initiative data of patients undergoing TCAR from 2016 to 2021. Surgeon and center volume were calculated based on the mean number of cases (MNC) performed yearly by each surgeon and center. The primary outcome was a composite endpoint of in-hospital stroke or death.

RESULTS

A total of 22,624 cases were included. Surgeon volume was divided into 3 quantiles: low (MNC = 4), medium (MNC = 10), and high (MNC = 26). Center volume was also divided into low (MNC = 14), medium (MNC = 32), and high (MNC = 64). After adjusting for potential confounders, and when compared with high-volume centers, low and medium center volumes were not associated with any increased odds of in-hospital stroke and death, stroke, death, or stroke with transient ischemic attack (TIA). Compared with high-volume surgeons, low surgeons' volume was associated with a higher odd of stroke (odds ratio 1.5, 95% CI 1.1 to 2.04, p = 0.008), and stroke and TIA (OR 1.5, 95% CI 1.2 to 1.9, p = 0.002). However, medium surgeon volume was not associated with higher odds of stroke and death, stroke, and stroke with TIA. Neither low nor medium surgeon volume was associated with a difference in mortality compared with high surgeon volume.

CONCLUSIONS

In this retrospective study, center volume was not associated with any differences in outcomes among patients undergoing TCAR. On the other hand, surgeons with low volume were associated with a higher risk of stroke, death, or MI and stroke or TIA when compared with high surgeon volume. There was no difference in outcomes between medium and high surgeon volume.

Non-White Patients Have a Higher Risk of Stroke Following Transcarotid Artery Revascularization

INTRODUCTION

Carotid artery revascularization has traditionally been performed by either a carotid endarterectomy or carotid artery stent. Large data analysis has suggested there are differences in perioperative outcomes with regards to race, with non-White patients (NWP) having worse outcomes of stroke, restenosis and return to the operating room (RTOR). The introduction of transcarotid artery revascularization (TCAR) has started to shift the paradigm of carotid disease treatment. However, to date, there have been no studies assessing the difference in postoperative outcomes after TCAR between racial groups.

METHODS

All patients from 2016 to 2021 in the Vascular Quality Initiative who underwent TCAR were included in our analysis. Patients were split into two groups based on race: individuals who identified as White and a second group that comprised all other races. Demographic and clinical variables were compared using Student's t-Test and chi-square test of independence. Logistic regression analysis was performed to determine the impact of race on perioperative outcomes of stroke, myocardial infarction (MI), death, restenosis, RTOR, and transient ischemic attack (TIA).

RESULTS

The cohort consisted of 22,609 patients: 20,424 (90.3%) White patients and 2185 (9.7%) NWP. After adjusting for sex, diabetes, hypertension, coronary artery disease, history of prior stroke or TIA, symptomatic status, and high-risk criteria at time of TCAR, there was a significant difference in postoperative stroke, with 63% increased risk in NWP (odds ratio = 1.63, 95% confidence interval: 1.11-2.40, P = 0.014). However, we found no significant difference in the odds of MI, death, postoperative TIA, restenosis, or RTOR when comparing NWP to White patients.

CONCLUSIONS

This study demonstrates that NWP have increased risk of stroke but similar outcomes of death, MI, RTOR and restenosis following TCAR. Future studies are needed to elucidate and address the underlying causes of racial disparity in carotid revascularization.

Assessing the volume-outcome relationship of carotid artery stenting in nationwide administrative data: a challenge of patient population bias

BACKGROUND

Studies have shown an association between surgical treatment volume and improved quality metrics. This study evaluated nationwide results in carotid artery stenting (CAS) procedural readmission rates, costs, and length of stay based on hospital treatment volume.

METHODS

We used the Nationwide Readmissions Database for carotid stenosis from 2010 to 2015. Patients receiving CAS were matched based on demographics, illness severity, and relevant comorbidities. Patients were matched 1:1 between low- and high-volume centers using a non-parametric preprocessing matching program to adjust for parametric causal inferences. Nearest-neighbor propensity score matching was performed using logit distance.

RESULTS

Low- and high-volume centers admitted a mean (SD) of 4.68 (3.79) and 25.10 (16.86) patients undergoing CAS per hospital, respectively. Comorbidities were significantly different and initially could not be adequately matched. Because of significant differences in baseline patient population characteristics after attempted matching between low- and high-volume centers, we used propensity adjustment with multivariate analysis. Using this alternative approach, no significant differences were observed between low- and high-volume centers for the presence of any complication, postoperative stroke, postoperative myocardial infarction, and readmission at 30 days.

CONCLUSION

In 1:1 nearest-neighbor matching with a high number of patients, our analysis did not result in well-matched cohorts for the effect of case volume on outcomes. Comparing analytical techniques for various outcomes highlights that outcome disparities may not be related to quality differences based on hospital size, but rather variability in patient populations between low- and high-volume institutions.

Impact of Vascular Service Centralization on the Carotid Endarterectomy Pathway: A Study at the Bedfordshire, Luton, and Milton Keynes Vascular Network

Introduction Carotid endarterectomy (CEA) is the gold standard intervention for patients experiencing transient ischemic attacks (TIAs) or embolic strokes with >50% internal carotid artery (ICA) stenosis supplying index hemispheric territory. The recommended period for CEA is 14 days post-index event; this period carries a heightened risk for second ischemic events. However, implementation of this stringent timeline often encounters delays stemming from multifaceted factors. The centralization of vascular services, designed to enhance patient care, introduces a paradigm shift. Centralization's efficacy in improving patient outcomes, particularly in the CEA pathway, is a subject of ongoing investigation. Our study aims to discern the impact of centralized services on the timeliness of CEA for symptomatic carotid artery stenosis, shedding light on this complex interplay of factors. Methods This retrospective study analyzed CEA data at the Bedfordshire, Luton, and Milton Keynes Vascular Network between January 2021 and June 2023. Eligible patients exhibited symptomatic carotid artery stenosis, with asymptomatic cases; those unfit for surgery or receiving best medical therapy only were excluded. Patients were categorized by their primary referral location: Hub, Spoke-1, or Spoke-2. Demographic and referral data were collected, and timelines from symptom onset to surgery were recorded. Continuous variables were expressed as means and standard deviations, and categorical variables as counts and percentages. Box plots illustrated the relationship between referral origin and surgery timing, and the Classification and Regression Tree (CART) assessed second events. Statistical significance was determined using Fisher's exact and chi-square tests, with p<0.05 indicating significance. Results A total of 148 patients underwent CEA after implementing exclusion criteria. 35.5% (n=53) of patients were referred from the Hub, while 45.6% (n=67) and 18.8% (n=28) were from Spoke-1 and Spoke-2, respectively. 40% (n=59) received CEA within the recommended timeframe, and 15.4% (n=23) experienced a second ischemic event pre-surgery. Time from TIA clinic review to referral was 5.5±8 days and 16.4±20 days from vascular referral to surgery. Patterns of delays were observed, with Spoke-2 exhibiting the most significant delays. Notably, amaurosis fugax and embolic stroke correlated with recurrent ischemic events, emphasizing the importance of timely care in CEA. Conclusion Our study underscores the significant benefits and challenges of the Hub and Spoke model in vascular surgery. The growing referral delays from Spoke sites are concerning, emphasizing the need for a multi-disciplinary team approach within Spoke sites to ensure efficient and standardized care delivery.

Association between Hospital Carotid Endarterectomy Procedure Volumes and In-Hospital Mortality in São Paulo State

Background

Previous studies indicate an inverse relationship between hospital volume and mortality after carotid endarterectomy. However, data at the level of Brazil are lacking.

Objectives

To assess the relationship between hospital carotid endarterectomy procedure volumes and mortality in the state of São Paulo.

Methods

Data from the São Paulo State Hospital Information System on all carotid endarterectomies performed between 2015 and 2019 were analyzed. Hospitals were categorized into clusters by annual volume of surgeries (1-10, 11-25, and ≥26). Multiple logistic regression models were used to determine whether the volume of carotid endarterectomy procedures was an independent predictor of in-hospital mortality among patients undergoing this procedure.

Results

Crude in-hospital mortality was nearly 60 percent lower in patients who underwent carotid endarterectomy at the highest volume hospitals than among those who underwent endarterectomy at the lowest volume hospitals (unadjusted OR of survival to hospital discharge, 2.41; 95% CI, 1.11-5.23; p = 0.027). Although this lower rate represents 1.5 fewer deaths per 100 patients treated, high-volume centers are more likely than low-volume centers to perform elective procedures, thus the analysis did not retain statistical significance when adjusted for admission character (OR, 1.69; 95% CI, 0.74-3.87; p = 0.215).

Conclusions

In a contemporary Brazilian registry, higher volume carotid endarterectomy centers were associated with lower in-hospital mortality than lower volume centers. Further studies are needed to verify this relationship considering the presence of symptoms in patients.

Delays to revascularization for patients with chronic limb-threatening ischaemia

BACKGROUND

Vascular services in England are organized into regional hub-and-spoke models, with hubs performing arterial surgery. This study examined time to revascularization for chronic limb-threatening ischaemia (CLTI) within and across different care pathways, and its association with postrevascularization outcomes.

METHODS

Three inpatient and four outpatient care pathways were identified for patients with CLTI undergoing revascularization between April 2015 and March 2019 using Hospital Episode Statistics data. Differences in times from presentation to revascularization across care pathways were analysed using Cox regression. The relationship between postoperative outcomes and time to revascularization was evaluated by logistic regression.

RESULTS

Among 16 483 patients with CLTI, 9470 had pathways starting with admission to a hub or spoke hospital, whereas 7013 (42.5 per cent) were first seen at outpatient visits. Among the inpatient pathways, patients admitted to arterial hubs had shorter times to revascularization than those admitted to spoke hospitals (median 5 (i.q.r. 2-10) versus 12 (7-19) days; P < 0.001). Shorter times to revascularization were also observed for patients presenting to outpatient clinics at arterial hubs compared with spoke hospitals (13 (6-25) versus 26 (15-35) days; P < 0.001). Within most care pathways, longer delays to revascularizsation were associated with increased risks of postoperative major amputation and in-hospital death, but the effect of delay differed across pathways.

CONCLUSION

For patients with CLTI, time to revascularization was influenced by presentation to an arterial hub or spoke hospital. Generally, longer delays to revascularization were associated with worse outcomes, but the impact of delay differed across pathways.

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.

Editor's Choice - Distribution of Care and Hospital Incidence of Carotid Endarterectomy and Carotid Artery Stenting: A Secondary Analysis of German Hospital Episode Data

OBJECTIVE

This is a description of the German healthcare landscape regarding carotid artery disease, assessment of hospital incidence time courses for carotid endarterectomy (CEA) and carotid artery stenting (CAS), and simulation of potential effects of minimum hospital caseload requirements for CEA and CAS.

METHODS

The study is a secondary data analysis of diagnosis related group statistics data (2005-2016), provided by the German Federal Statistical Office. Cases encoded by German operation procedure codes for CEA or CAS and by International Classification of Diseases (ICD-10) codes for carotid artery disease were included. Hospitals were categorised into quartiles according to annual caseloads. Linear distances to the closest hospital fulfilling hypothetical caseload requirements were calculated.

RESULTS

A total of 132 411 and 33 709 patients treated with CEA and CAS from 2012 to 2016 were included. CEA patients had lower rates of myocardial infarction (1.4% vs. 1.8%) and death (1.2% vs. 4.0%), and CAS patients were more often treated after emergency admission (38.1% vs. 27.1%). Age standardised annual hospital incidences were 67.2 per 100 000 inhabitants for CEA and 16.3 per 100 000 inhabitants for CAS. The incidence for CEA declined from 2005 to 2016, with CAS rising again until 2016 after having declined from 2010 to 2013. Regarding distance from home to hospital, centres offering CEA are distributed more homogeneously across Germany, compared with those performing CAS. Hypothetical introduction of minimum annual caseloads (> 20 for CEA; > 10 for CAS) imply that 75% of the population would reach their hospital after travelling 45 km for CEA and 70 km for CAS.

CONCLUSION

Differences in spatial distribution mean that statutory minimum annual caseloads would have a greater impact on CAS accessibility than CEA in Germany. Presumably because of a decline in carotid artery disease and a transition towards individualised therapy for asymptomatic patients, hospital incidence for CEA has been declining.

Configuration of vascular services: a multiple methods research programme

Background

Vascular services is changing rapidly, having emerged as a new specialty with its own training and specialised techniques. This has resulted in the need for reconfiguration of services to provide adequate specialist provision and accessible and equitable services.

Objectives

To identify the effects of service configuration on practice, resource use and outcomes. To model potential changes in configuration. To identify and/or develop electronic data collection tools for collecting patient-reported outcome measures and other clinical information. To evaluate patient preferences for aspects of services other than health-related quality of life.

Design

This was a multiple methods study comprising multiple systematic literature reviews; the development of a new outcome measure for users of vascular services (the electronic Personal Assessment Questionnaire – Vascular) based on the reviews, qualitative studies and psychometric evaluation; a trade-off exercise to measure process utilities; Hospital Episode Statistics analysis; and the development of individual disease models and a metamodel of service configuration.

Setting

Specialist vascular inpatient services in England.

Data sources

Modelling and Hospital Episode Statistics analysis for all vascular inpatients in England from 2006 to 2018. Qualitative studies and electronic Personal Assessment Questionnaire – Vascular evaluation with vascular patients from the Sheffield area. The trade-off studies were based on a societal sample from across England.

Interventions

The data analysis, preference studies and modelling explored the effect of different potential arrangements for service provision on the resource use, workload and outcomes for all interventions in the three main areas of inpatient vascular treatment: peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. The electronic Personal Assessment Questionnaire – Vascular was evaluated as a potential tool for clinical data collection and outcome monitoring.

Main outcome measures

Systematic reviews assessed quality and psychometric properties of published outcome measures for vascular disease and the relationship between volume and outcome in vascular services. The electronic Personal Assessment Questionnaire – Vascular development considered face and construct validity, test–retest reliability and responsiveness. Models were validated using case studies from previous reconfigurations and comparisons with Hospital Episode Statistics data. Preference studies resulted in estimates of process utilities for aneurysm treatment and for travelling distances to access services.

Results

Systematic reviews provided evidence of an association between increasing volume of activity and improved outcomes for peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. Reviews of existing patient-reported outcome measures did not identify suitable condition-specific tools for incorporation in the electronic Personal Assessment Questionnaire – Vascular. Reviews of qualitative evidence, primary qualitative studies and a Delphi exercise identified the issues to be incorporated into the electronic Personal Assessment Questionnaire – Vascular, resulting in a questionnaire with one generic and three disease-specific domains. After initial item reduction, the final version has 55 items in eight scales and has acceptable psychometric properties. The preference studies showed strong preference for endovascular abdominal aortic aneurysm treatment (willingness to trade up to 0.135 quality-adjusted life-years) and for local services (up to 0.631 quality-adjusted life-years). A simulation model with a web-based interface was developed, incorporating disease-specific models for abdominal aortic aneurysm, peripheral arterial disease and carotid artery disease. This predicts the effects of specified reconfigurations on workload, resource use, outcomes and cost-effectiveness. Initial exploration suggested that further reconfiguration of services in England to accomplish high-volume centres would result in improved outcomes, within the bounds of cost-effectiveness usually considered acceptable in the NHS.

Limitations

The major source of evidence to populate the models was Hospital Episode Statistics data, which have limitations owing to the complexity of the data, deficiencies in the coding systems and variations in coding practice. The studies were not able to address all of the potential barriers to change where vascular services are not compliant with current NHS recommendations.

Conclusions

There is evidence of potential for improvement in the clinical effectiveness and cost-effectiveness of vascular services through further centralisation of sites where major vascular procedures are undertaken. Preferences for local services are strong, and this may be addressed through more integrated services, with a range of services being provided more locally. The use of a web-based tool for the collection of clinical data and patient-reported outcome measures is feasible and can provide outcome data for clinical use and service evaluation.

Future work

Further evaluation of the economic models in real-world situations where local vascular service reconfiguration is under consideration and of the barriers to change where vascular services do not meet NHS recommendations for service configuration is needed. Further work on the electronic Personal Assessment Questionnaire – Vascular is required to assess its acceptability and usefulness in clinical practice and to develop appropriate report formats for clinical use and service evaluation. Further studies to assess the implications of including non-health-related preferences for care processes, and location of services, in calculations of cost-effectiveness are required.

Study registration

This study is registered as PROSPERO CRD42016042570, CRD42016042573, CRD42016042574, CRD42016042576, CRD42016042575, CRD42014014850, CRD42015023877 and CRD42015024820.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 5. See the NIHR Journals Library website for further project information.

Impact of Frailty on Clinical Outcomes after Carotid Artery Revascularization

BACKGROUND

Frailty has been increasingly recognized as an important risk factor for vascular procedures. To assess the impact of frailty on clinical outcomes and resource utilization in patients undergoing carotid revascularization using a national cohort.

METHODS

The 2005-2017 National Inpatient Sample was used to identify patients who underwent carotid endarterectomy (CEA) or carotid stenting (CAS). Patients were classified as frail using diagnosis codes defined by the Johns Hopkins Adjusted Clinical Groups frailty indicator. Multivariable regression was used to evaluate associations between frailty and in-hospital mortality, postoperative stroke, myocardial infarction (MI), hospitalization costs, and length of stay (LOS).

RESULTS

Of 1,426,343 patients undergoing carotid revascularization, 59,158 (4.2%) were identified as frail. Among frail patients, 79.4% underwent CEA and 20.6% underwent CAS. Compared to CEA, a greater proportion of patients undergoing CAS were frail (6.0% vs. 3.8%, P < 0.001). Compared to the nonfrail cohort, frail patients had higher rates of mortality (2.2% vs. 0.5%, P < 0.001), postoperative stroke (2.6% vs. 1.0%, P < 0.001), MI (2.2% vs. 0.8%, P < 0.001), and stroke/death (4.4% vs. 1.4%, P < 0.001). After adjustment, frailty was associated with increased odds of mortality (AOR = 1.59, 95% CI: 1.30-1.80, P < 0.001), stroke (AOR = 1.66, 95% CI: 1.38-1.83 P < 0.001), MI (AOR = 1.51, 95% CI: 1.29-1.72, P < 0.001), and stroke/death (AOR = 1.62, 95% CI: 1.45-1.81, P < 0.001). Furthermore, frailty was associated with increased hospitalization costs (β = +$5,980, 95% CI: $5,490-$6,470, P < 0.001) and LOS (β = +2.6 days, 95% CI: 2.4-2.8, P < 0.001).

CONCLUSIONS

Frailty is associated with adverse outcomes and greater resource use for those undergoing carotid revascularization. Risk models should include an assessment of frailty to guide management and improve outcomes for these high-risk patients.

The Relationship Between Carotid Revascularization Procedural Volume and Perioperative Outcomes in Australia and New Zealand

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) prevent stroke in selected patients. However, each intervention carries a risk of perioperative complications including stroke or death (S/D). We aimed to determine the relationship between operator volume, hospital volume, and the perioperative risk of S/D in carotid revascularization in Australia and New Zealand. Retrospective analysis was performed on prospectively collected data extracted from the Australasian Vascular Audit between 2010 and 2017. Annual caseload volume was analyzed in quintiles (Q) using multivariate regression to assess its impact on perioperative S/D. Carotid endarterectomy procedures (n = 16 765) demonstrated higher S/D rates for lower-volume operators (2.21% for Q1-Q3 [1-17 annual cases] vs 1.76% for Q4-Q5 [18-61 annual cases]; odds ratio [OR]: 1.28; 95% CI: 1.001-1.64; P = .049). Carotid artery stenting procedures (n = 1350) also demonstrated higher S/D rates for lower-volume operators (2.63% for Q1-Q3 [1-11 annual cases] vs 0.37% for Q4-Q5 [12-31 annual cases]; OR: 6.11; 95% CI: 1.27-29.33; P = .024). No significant hospital volume-outcome effect was observed for either procedure. An inverse relationship was demonstrated between operator volume and perioperative S/D rates following CEA and CAS. Consideration of minimum operator thresholds, restructuring of services and networked referral pathways of care in Australia and New Zealand, would likely result in improved patient outcomes.

Referral patterns for catheter-directed thrombolysis for iliofemoral deep venous thrombosis

OBJECTIVES

Post thrombotic syndrome (PTS) is a serious complication of deep venous thromboses (DVTs). PTS occurs more frequently and severely following iliofemoral DVT compared to distal DVTs. Catheter directed thrombolysis (CDT) of iliofemoral DVTs may reduce PTS incidence and severity.We aimed to determine the rate of iliofemoral DVT within our institution, their subsequent management, and compliance with NICE guidelines.

METHODS

Retrospective review of all DVTs diagnosed over a 3-year period was conducted. Cases of iliofemoral DVT were identified using ICD-10 codes from patient notes, and radiology reports of Duplex scans. Further details were retrieved, such as patient demographics and referrals to vascular services. NICE guidance was applied to determine if patients would have been suitable for CDT. A survey was sent to clinicians within medicine to identify awareness of CDT and local guidelines for iliofemoral DVT management.

RESULTS

225 patients with lower limb DVTs were identified. Of these, 96 were radiographically confirmed as iliofemoral DVTs. The median age was 77. 67.7% of iliofemoral DVTs affected the left leg. Right leg DVTs made up 30.2% and 2.1% were bilateral DVTs. Of the 96 iliofemoral DVTs, 21 were deemed eligible for CDT. Only 3 patients (14.3%) were referred to vascular services, and 3 received thrombolysis.From our survey, 95.5% of respondents suggested anticoagulation alone as management for iliofemoral DVT. Only one respondent recommended referral to vascular services. There was a knowledge deficiency regarding venous anatomy, including superficial versus deep veins.

CONCLUSIONS

CDT and other mechanochemical procedures have been shown to improve outcomes of patients post-iliofemoral DVT, however a lack of awareness regarding CDT as a management option results in under-referral to vascular services. We suggest closer relations between vascular services and their "tributary" DVT clinics, development of guidelines and robust care pathways in the management of iliofemoral DVT.

Carotid endarterectomy surgeon volumes in contemporary practice: A comparison to randomized trial inclusion criteria

BACKGROUND

Clinical decisions regarding the utility of carotid revascularization are informed by randomized controlled trial (RCT) results. However, RCTs generally require participating surgeons to meet strict inclusion criteria with respect to procedure volume. The purpose of this study was to compare annual surgeon volume for carotid endarterectomy (CEA) in contemporary practice to RCT inclusion thresholds.

METHODS

Surgeon volume thresholds were identified in 17 RCTs evaluating the efficacy of CEA (1986-present, n = 17). Contemporary annual surgeon volumes (2012-2017) were identified by aggregating data from the Medicare Provider Utilization Database and Healthcare Cost and Utilization Project Network (HCUP), and compared to RCT inclusion thresholds. Further comparisons were performed over time, and across specialties (i.e., vascular surgeon vs. other, based on board certification associated with provider NPI).

RESULTS

Minimal surgeon volume in 17 RCTs ranged from 10 to 25 CEA annually when specific case volumes were required. From 2012 to 2017, CEA incidence in Medicare beneficiaries declined from 68,608 to 56,004 and became increasingly consolidated in fewer providers (7,331 vs. 6,626). However, in 2016 only 26.2% of surgeons performing CEA in Medicare beneficiaries would have met the least stringent volume requirement (10 CEA/year). Only 6.5% of surgeons performing CEA met the most stringent RCT volume threshold (25 cases/year) during the same time period. In 2017, 819 vascular surgeons (25.5% of those certified in the specialty) performed >10 CEA in Medicare beneficiaries.

CONCLUSIONS

The majority of surgeons performing CEA do not meet the annual volume thresholds required for participation in the RCTs that have evaluated the efficacy of carotid revascularization. Given the established volume-outcome relationship in CEA, the disparity between surgeon experience in the context of RCTs versus contemporary practice is concerning. These findings have potential implications for informed decision-making, hospital privileging, and regionalization of care.

Association of hospital and surgeon volume with mortality following major surgical procedures: Meta-analysis of meta-analyses of observational studies

Accumulation of the literature has suggested an inverse association between healthcare provider volume and mortality for a wide variety of surgical procedures. This study aimed to perform meta-analysis of meta-analyses (umbrella review) of observational studies and to summarize existing evidence for associations of healthcare provider volume with mortality in major operations.We searched MEDLINE, SCOPUS, and Cochrane Library, and screening of references.Meta-analyses of observational studies examining the association of hospital and surgeon volume with mortality following major operations. The primary outcome is all-cause short-term morality after surgery. Meta-analyses of observational studies of hospital/surgeon volume and mortality were included. Overall level of evidence was classified as convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and non-significant (class V) based on the significance of the random-effects summary odds ratio (OR), number of cases, small-study effects, excess significance bias, prediction intervals, and heterogeneity.Twenty meta-analyses including 4,520,720 patients were included, with 19 types of surgical procedures for hospital volume and 11 types of surgical procedures for surgeon volume. Nominally significant reductions were found in odds ratio in 82% to 84% of surgical procedures in both hospital and surgeon volume-mortality associations. To summarize the overall level of evidence, however, only one surgical procedure (pancreaticoduodenectomy) fulfilled the criteria of class I and II for both hospital and surgeon volume and mortality relationships, with a decrease in OR for hospital (0.42, 95% confidence interval[CI] [0.35-0.51]) and for surgeon (0.38, 95% CI [0.30-0.49]), respectively. In contrast, most of the procedures appeared to be weak or "non-significant."Only a very few surgical procedures such as pancreaticoduodenectomy appeared to have convincing evidence on the inverse surgeon volume-mortality associations, and yet most surgical procedures resulted in having weak or "non-significant" evidence. Therefore, healthcare professionals and policy makers might be required to steer their centralization policy more carefully unless more robust, higher-quality evidence emerges, particularly for procedures considered as having a weak or non-significant evidence level including total knee replacement, thyroidectomy, bariatric surgery, radical cystectomy, and rectal and colorectal cancer resections.

Incisional Seeding of Metastatic Squamous Cell Carcinoma Following Carotid Endarterectomy: An Unusual Case of an Unknown Primary Cancer Presenting as a Presumed Neck Abscess

BACKGROUND

Carotid endarterectomy (CEA) is a safe and effective procedure, with a low risk of complications when performed by experienced surgeons. Postoperative infections are particularly rare, reportedly affecting less than 1% of cases. Incisional metastases have not been described.

OBJECTIVE

To describe a previously unreported complication, the incisional seeding of metastatic squamous cell carcinoma (SCC) during neck dissection, which presented and was treated as a presumed postoperative neck abscess.

METHODS

Clinical records were reviewed regarding a 73-yr-old female who underwent routine CEA and presented 2 mo postoperatively with neck induration and erythema. Tissue submitted during the initial CEA was reexamined given the updated clinical history.

RESULTS

Postoperatively, a complex, multi-cystic fluid collection beneath the incision was identified and percutaneously drained. Although cultures were negative, an infection was favored and antibiotic therapy initiated. The patient's symptoms worsened prompting surgical exploration, and tissue sent for pathological examination was consistent with metastatic SCC. Retrospective analysis of a lymph node excised during the initial dissection also revealed tumor deposits, indicating that the surgical site had been seeded during exposure. A primary origin was not identified.

CONCLUSION

The time from initial presentation of postoperative complications to a final diagnosis of metastatic SCC was 2 mo, during which time the patient was treated as having a postoperative infection. Further investigations were consistent with diffuse and incurable metastatic disease. This report highlights the diagnostic challenges and potential avoidance strategies when dealing with rare complications following CEA.

Developing a novel international undergraduate surgical masterclass during a financial crisis: our 4-year experience

BACKGROUND

Essential Skills in the Management of Surgical Cases (ESMSC) is a novel 3-day international undergraduate surgical masterclass. Its current curriculum (Cores integrated for Research-Ci4R) is built on a tetracore, multiclustered architecture combining high-fidelity and low-fidelity simulation-based learning (SBL), with applied and basic science case-based workshops, and non-technical skills modules. We aimed to report our experience in setting up ESMSC during the global financial crisis.

METHODS

We report the evolution of our curriculum's methodology and summarised the research outcomes related to the objective performance improvement of delegates, the educational environment of the course and the use of mixed-fidelity SBL. Feedback from the last three series of the course was prospectively collected and analysed using univariate statistics on IBM SPSS V.23.

RESULTS

311 medical students across the European Union (EU) were selected from a competitive pool of 1280 applicants during seven series of the course between 2014 and 2017. During this period, curriculum 14 s evolved to the final Ci4R version, which integrates a tetracore structure combining 32 stations of in vivo, ex vivo and dry lab SBL with small group teaching workshops. Ci4R was positively perceived across different educational background students (p>0.05 for any comparison).

CONCLUSIONS

ESMSC is considered an innovative and effective multidisciplinary teaching model by delegates, where it improves delegates objective performance in basic surgical skills. Our experience demonstrates provision of high-quality and free surgical education during a financial crisis, which evolved through a dynamic feedback mechanism. The prospective recording and subsequent analysis of curriculum evolution provides a blueprint to direct development of effective surgical education courses that can be adapted to local needs.

Meta-analysis of the procedural risks of carotid endarterectomy and carotid artery stenting over time

Background

Stroke/death rates within 30 days of carotid endarterectomy (CEA) and carotid artery stenting (CAS) in RCTs inform current clinical guidelines. However, the risks may have changed in recent years with wider use of effective stroke prevention therapies, especially statins, improved patient selection and growing operator expertise. The aim of this study was to investigate whether the procedural stroke/death risks from CEA and CAS have changed over time.

Methods

MEDLINE and Embase were searched systematically from inception to May 2016 for observational cohort studies of CEA and CAS. Studies included reported on more than 1000 patients, with 30‐day outcomes after the procedure according to patients' symptom status (recent stroke or transient ischaemic attack). Restricted maximum likelihood random‐effects and meta‐regressions methods were used to synthesize procedural stroke/death rates of CEA and CAS according to year of study recruitment completion.

Results

Fifty‐one studies, including 223 313 patients undergoing CEA and 72 961 undergoing CAS, were reviewed. Procedural stroke/death risks of CEA decreased over time in symptomatic and asymptomatic patients. Risks were substantially lower in studies completing recruitment in 2005 or later, both in symptomatic (5·11 per cent before 2005 versus 2·68 per cent from 2005 onwards; P = 0·002) and asymptomatic (3·17 versus 1·50 per cent; P < 0·001) patients. Procedural stroke/death rates of CAS did not change significantly over time (4·77 per cent among symptomatic and 2·59 per cent among asymptomatic patients). There was substantial heterogeneity in event rates and recruitment periods were long.

Conclusions

Risks of procedural stroke/death following CEA appear to have decreased substantially. There was no evidence of a change in stroke/death rates following CAS.

Endarterectomy outcomes improving

Surgeon, not institution, case volume is associated with limb outcomes after lower extremity bypass for critical limb ischemia in the Vascular Quality Initiative

OBJECTIVE

Studies from large administrative databases have demonstrated associations between institutional case volume and outcomes after lower extremity bypass (LEB). We hypothesized that increased institutional and surgeon volume would be associated with improved outcomes after LEB. Using a national, prospectively collected clinical database, the objective of this study was to determine the effects of both surgeon and institutional volume on outcomes after LEB.

METHODS

The Vascular Quality Initiative (VQI) was queried to identify all LEBs for critical limb ischemia or claudication between 2004 and 2014. Average annual case volume was calculated by dividing an institution's or surgeon's total LEB volume by the number of years they reported to the VQI. Institutional and surgeon volumes were analyzed as continuous variables to determine the impact of volume on major adverse cardiac events (MACEs), major adverse limb events (MALEs), graft patency, and amputation-free survival. Hierarchical regression models were used with cases clustered by surgeon and center. Time-dependent outcomes were evaluated with multivariable shared frailty Cox proportional hazards models.

RESULTS

From 2004 to 2014, there were 14,678 LEB operations performed at 114 institutions by 587 surgeons. Average annual institutional volume ranged from 1.0 to 137.5 LEBs per year, with a median of 26.9 (interquartile range, 14-45.3). Average annual surgeon volume ranged from 1 to 52 LEBs per year with a median of 5.7 (interquartile range, 2.5-9.3). Institutional LEB volume was not associated with MACEs or MALEs or with loss of patency. However, average annual surgeon volume was independently associated with reduced MALEs and improved primary patency. Institutional and surgeon volume did not predict MACEs.

CONCLUSIONS

In contradistinction to previous studies, there was no relationship in this study between institutional LEB volume and outcomes after LEB. However, greater average annual surgeon volume was associated with improved primary patency and decreased risk of MALEs. Open LEB remains a safe and effective procedure for limb salvage. Limb-related outcomes in critical limb ischemia and claudication will be optimized if surgeons maintain adequate volume of LEB.

Carotid Endarterectomy and Carotid Artery Stenting in the US Medicare Population, 1999-2014

IMPORTANCE

Carotid endarterectomy and carotid artery stenting are the leading approaches to revascularization for carotid stenosis, yet contemporary data on trends in rates and outcomes are limited.

OBJECTIVE

To describe US national trends in performance and outcomes of carotid endarterectomy and stenting among Medicare beneficiaries from 1999 to 2014.

DESIGN, SETTING, AND PARTICIPANTS

Serial cross-sectional analysis of Medicare fee-for-service beneficiaries aged 65 years or older from 1999 to 2014 using the Medicare Inpatient and Denominator files. Spatial mixed models adjusted for age, sex, and race were fit to calculate county-specific risk-standardized revascularization rates. Mixed models were fit to assess trends in outcomes after adjustment for demographics, comorbidities, and symptomatic status.

EXPOSURES

Carotid endarterectomy and carotid artery stenting.

MAIN OUTCOMES AND MEASURES

Revascularization rates per 100 000 beneficiary-years of fee-for-service enrollment, in-hospital mortality, 30-day stroke or death, 30-day stroke, myocardial infarction, or death, 30-day all-cause mortality, and 1-year stroke.

RESULTS

During the study, 937 111 unique patients underwent carotid endarterectomy (mean age, 75.8 years; 43% women) and 231 077 underwent carotid artery stenting (mean age, 75.4 years; 49% women). There were 81 306 patients who underwent endarterectomy in 1999 and 36 325 in 2014; national rates per 100 000 beneficiary-years decreased from 298 in 1999-2000 to 128 in 2013-2014 (P < .001). The number of patients who underwent stenting ranged from 10 416 in 1999 to 22 865 in 2006 (an increase per 100 000 beneficiary-years from 40 in 1999-2000 to 75 in 2005-2006; P < .001); by 2014, there were 10 208 patients who underwent stenting and the rate decreased to 38 per 100 000 beneficiary-years (P < .001). Outcomes improved over time despite increases in vascular risk factors (eg, hypertension prevalence increased from 67% to 81% among patients who underwent endarterectomy and from 61% to 70% among patients who underwent stenting) and the proportion of symptomatic patients (all P < .001). There were adjusted annual decreases in 30-day ischemic stroke or death of 2.90% (95% CI, 2.63% to 3.18%) among patients who underwent endarterectomy and 1.13% (95% CI, 0.71% to 1.54%) among patients who underwent stenting; an absolute decrease from 1999 to 2014 was observed for endarterectomy (1.4%; 95% CI, 1.2% to 1.5%) but not stenting (-0.1%; 95% CI, -0.5% to 0.4%). Rates for 1-year ischemic stroke decreased after endarterectomy (absolute decrease, 3.5% [95% CI, 3.2% to 3.7%]; adjusted annual decrease, 2.17% [95% CI, 2.00% to 2.34%]) and stenting (absolute decrease, 1.6% [95% CI, 1.2% to 2.1%]; adjusted annual decrease, 1.86% [95% CI, 1.45%-2.26%]). Additional improvements were noted for in-hospital mortality, 30-day stroke, myocardial infarction, or death, and 30-day all-cause mortality as well as within demographic subgroups.

CONCLUSIONS AND RELEVANCE

Among fee-for-service Medicare beneficiaries, the performance of carotid endarterectomy declined from 1999 to 2014, whereas the performance of carotid artery stenting increased until 2006 and then declined from 2007 to 2014. Outcomes improved despite increases in vascular risk factors.

Hospital volume and mortality for 25 types of inpatient treatment in German hospitals: observational study using complete national data from 2009 to 2014

OBJECTIVES

To explore the existence and strength of a relationship between hospital volume and mortality, to estimate minimum volume thresholds and to assess the potential benefit of centralisation of services.

DESIGN

Observational population-based study using complete German hospital discharge data (Diagnosis-Related Group Statistics (DRG Statistics)).

SETTING

All acute care hospitals in Germany.

PARTICIPANTS

All adult patients hospitalised for 1 out of 25 common or medically important types of inpatient treatment from 2009 to 2014.

MAIN OUTCOME MEASURE

Risk-adjusted inhospital mortality.

RESULTS

Lower inhospital mortality in association with higher hospital volume was observed in 20 out of the 25 studied types of treatment when volume was categorised in quintiles and persisted in 17 types of treatment when volume was analysed as a continuous variable. Such a relationship was found in some of the studied emergency conditions and low-risk procedures. It was more consistently present regarding complex surgical procedures. For example, about 22 000 patients receiving open repair of abdominal aortic aneurysm were analysed. In very high-volume hospitals, risk-adjusted mortality was 4.7% (95% CI 4.1 to 5.4) compared with 7.8% (7.1 to 8.7) in very low volume hospitals. Theminimum volume above which risk of death would fall below the average mortality was estimated as 18 cases per year. If all hospitals providing this service would perform at least 18 cases per year, one death among 104 (76 to 166) patients could potentially be prevented.

CONCLUSIONS

Based on complete national hospital discharge data, the results confirmed volume-outcome relationships for many complex surgical procedures, as well as for some emergency conditions and low-risk procedures. Following these findings, the study identified areas where centralisation would provide a benefit for patients undergoing the specific type of treatment in German hospitals and quantified the possible impact of centralisation efforts.

Influence of hospital volume on nephrectomy mortality and complications: a systematic review and meta-analysis stratified by surgical type

OBJECTIVES

The provision of complex surgery is increasingly centralised to high-volume (HV) specialist hospitals. Evidence to support nephrectomy centralisation however has been inconsistent. We conducted a systematic review and meta-analysis to determine the association between hospital case volumes and perioperative outcomes in radical nephrectomy, partial nephrectomy and nephrectomy with venous thrombectomy.

METHODS

Medline, Embase and the Cochrane Library were searched for relevant studies published between 1990 and 2016. Pooled effect estimates for nephrectomy mortality and complications were calculated for each nephrectomy type using the DerSimonian and Laird random-effects model. Sensitivity analyses were performed to examine the effects of heterogeneity on the pooled effect estimates by excluding studies with the heaviest weighting, lowest methodological score and most likely to introduce bias from misclassification of standardised hospital volume.

RESULTS

Some 226 372 patients from 16 publications were included in our review and meta-analysis. Considerable between-study heterogeneity was noted and only a few reported volume-outcome relationships specifically in partial nephrectomy or nephrectomy with venous thrombectomy.HV hospitals were correlated with a 26% and 52% reduction in mortality for radical nephrectomy (OR 0.74, 95% CI 0.61 to 0.90, p<0.01) and nephrectomy with venous thrombectomy (OR 0.48, 95% CI 0.29 to 0.81, p<0.01), respectively. In addition, radical nephrectomy in HV hospitals was associated with an 18% reduction in complications (OR 0.82, 95% CI 0.73 to 0.92, p<0.01). No significant volume-outcome relationship in mortality (OR 0.84, 95% CI 0.31 to 2.26, p=0.73) or complications (OR 0.85, 95% CI 0.55 to 1.30, p=0.44) was observed for partial nephrectomy.

CONCLUSIONS

Our findings suggest that patients undergoing radical nephrectomy have improved outcomes when treated by HV hospitals. Evidence of this in partial nephrectomy and nephrectomy with venous thrombectomy is however not yet clear and could be secondary to the low number of studies included and the small patient number in our analyses. Further investigation is warranted to establish the full potential of nephrectomy centralisation particularly as existing evidence is of low quality with significant heterogeneity.

Systematic review of carotid artery procedures and the volume-outcome relationship in Europe

BACKGROUND

Hospitals that conduct more procedures on the carotid arteries may achieve better outcomes. In the context of ongoing reconfiguration of UK vascular services, this systematic review was conducted to evaluate the relationship between the volume of carotid procedures and outcomes, including mortality and stroke.

METHODS

Searches of electronic databases identified studies that reported the effect of hospital or clinician volume on outcomes. Reference and citation searches were also performed. Inclusion was restricted to European populations on the basis that the model of healthcare delivery is similar across Europe, but differs from that in the USA and elsewhere. Analyses of hospital and clinician volume, and carotid endarterectomy (CEA) and carotid artery stenting (CAS) were conducted separately.

RESULTS

Eleven eligible studies were identified (233 411 participants), five from the UK, two from Sweden, one each from Germany, Finland and Italy, and a combined German, Austrian and Swiss population. All studies were observational. Two large studies (179 736 patients) suggested an inverse relationship between hospital volume and mortality (number needed to treat (NNT) as low as 165), and combined mortality and stroke (NNT as low as 93), following CEA. The evidence was less clear for CAS; multiple analyses in three studies did not identify convincing evidence of an association. Limited data are available on the relationship between clinician volume and outcome in CAS; in CEA, an inverse relationship was identified by two of three small studies.

CONCLUSION

The evidence from the largest and highest-quality studies included in this review support the centralization of CEA.

The Impact of System Factors on Quality and Safety in Arterial Surgery: A Systematic Review

OBJECTIVE

A systems approach to patient safety proposes that a wide range of factors contribute to surgical outcome, yet the impact of team, work environment, and organisational factors, is not fully understood in arterial surgery. The aim of this systematic review is to summarize and discuss what is already known about the impact of system factors on quality and safety in arterial surgery.

DATA SOURCES

A systematic review of original research papers in English using MEDLINE, Embase, PsycINFO, and Cochrane databases, was performed according to PRISMA guidelines.

REVIEW METHODS

Independent reviewers selected papers according to strict inclusion and exclusion criteria, and using predefined data fields, extracted relevant data on team, work environment, and organisational factors, and measures of quality and/or safety, in arterial procedures.

RESULTS

Twelve papers met the selection criteria. Study endpoints were not consistent between papers, and most failed to report their clinical significance. A variety of tools were used to measure team skills in five papers; only one paper measured the relationship between team factors and patient outcomes. Two papers reported that equipment failures were common and had a significant impact on operating room efficiency. The influence of hospital characteristics on failure-to-rescue rates was tested in one large study, although their conclusions were limited to the American Medicare population. Five papers implemented changes in the patient pathway, but most studies failed to account for potential confounding variables.

CONCLUSIONS

A small number of heterogenous studies have evaluated the relationship between system factors and quality or safety in arterial surgery. There is some evidence of an association between system factors and patient outcomes, but there is more work to be done to fully understand this relationship. Future research would benefit from consistency in definitions, the use of validated assessment tools, measurement of clinically relevant endpoints, and adherence to national reporting guidelines.

Significant Association of Annual Hospital Volume With the Risk of Inhospital Stroke or Death Following Carotid Endarterectomy but Likely Not After Carotid Stenting

Background—

Associations between hospital volume and the risk of stroke or death following carotid endarterectomy (CEA) and carotid artery stenting (CAS) on a national level in Germany were analyzed.

Methods and Results—

Secondary data analysis using microdata from the nationwide statutory German quality assurance database on all surgical or endovascular carotid interventions on the extracranial carotid artery between 2009 and 2014. Hospitals were categorized into empirically determined quintiles according to the annual case volume. The resulting volume thresholds were 10, 25, 46, and 79 for CEA and 2, 6, 12, and 26 for CAS procedures. The primary outcome was any stroke or death before hospital discharge. For risk-adjusted analyses, a multilevel regression model was applied. The analysis included 161 448 CEA and 17 575 CAS procedures. In CEA patients, the crude risk of stroke or death decreased monotonically from 4.2% (95% confidence interval, 3.6%–4.9%) in low-volume hospitals (first quintile 1–10 CEA per year) to 2.1% (2.0%–2.2%) in hospitals providing ≥80 CEA per year (fifth quintile; P <0.001 for trend). The overall risk of any stroke or death in CAS patients was 3.7% (3.5%–4.0%), but no trend on annual volume was seen ( P =0.304). Risk-adjusted analyses confirmed a significant inverse relationship between hospital volume (categorized or continuous) and the risk of stroke or death after CEA but not CAS procedures.

Conclusions—

An inverse volume–outcome relationship in CEA-treated patients was demonstrated. No significant association between hospital volume and the risk of stroke or death was found for CAS.

The effectiveness of a pay for performance program on diabetes care in Taiwan: A nationwide population-based longitudinal study

Over the past two decades, studies have widely examined the effectiveness of pay-for-performance (P4P) programs by conducting biochemical tests and assessing complications; however, the reported effectiveness of such programs among participants selected through purposeful sampling is controversial. Therefore, the objective of the current study was to analyze the effectiveness of a P4P program on patients' prognoses, including hospitalization for chronic diabetic complications, and all-cause mortality during specific follow-up years by using a nationwide population-based database in Taiwan. Based on 125,315 newly diagnosed type 2 diabetes patient cohort during 2002-2006, two control sets were designed by propensity-score-matching strategy according to participation of P4P program and followed up to 2012. The results indicated that full participants demonstrated the lowest risks of developing complications and all-cause mortality compared with nonparticipants. These findings confirm the long-term effect of P4P programs on full participants and reveal that this effect is not due to confounding variables. The results indicate the importance of performance management and adherence to interventions for patients with chronic diseases in a long-term observation. Comprehensive and continuous care is suggested to improve patient prognosis and quality of care.

Temporal trends in safety of carotid endarterectomy in asymptomatic patients: systematic review

OBJECTIVE

To systematically review temporal changes in perioperative safety of carotid endarterectomy (CEA) in asymptomatic individuals in trial and registry studies.

METHODS

The MEDLINE and EMBASE databases were searched using the terms "carotid" and "endarterectomy" and "asymptomatic" from 1947 to August 23, 2014. Articles dealing with 50%-99% stenosis in asymptomatic individuals were included and low-volume studies were excluded. The primary endpoint was 30-day stroke or death and the secondary endpoint was 30-day all-cause mortality. Statistical analysis was performed using random-effects meta-regression for registry data and for trial data graphical interpretation alone was used.

RESULTS

Six trials (n = 4,431 procedures) and 47 community registries (n = 204,622 procedures) reported data between 1983 and 2013. Registry data showed a significant decrease in postoperative stroke or death incidence over the period 1991-2010, equivalent to a 6% average proportional annual reduction (95% credible interval [CrI] 4%-7%; p < 0.001). Considering postoperative all-cause mortality, registry data showed a significant 5% average proportional annual reduction (95% CrI 3%-9%; p < 0.001). Trial data showed a similar visual trend.

CONCLUSIONS

CEA is safer than ever before and high-volume registry results closely mirror the results of trials. New benchmarks for CEA are a stroke or death risk of 1.2% and a mortality risk of 0.4%. This information will prove useful for quality improvement programs, for health care funders, and for those re-examining the long-term benefits of asymptomatic revascularization in future trials.

Optimization modeling to maximize population access to comprehensive stroke centers

OBJECTIVE

The location of comprehensive stroke centers (CSCs) is critical to ensuring rapid access to acute stroke therapies; we conducted a population-level virtual trial simulating change in access to CSCs using optimization modeling to selectively convert primary stroke centers (PSCs) to CSCs.

METHODS

Up to 20 certified PSCs per state were selected for conversion to maximize the population with 60-minute CSC access by ground and air. Access was compared across states based on region and the presence of state-level emergency medical service policies preferentially routing patients to stroke centers.

RESULTS

In 2010, there were 811 Joint Commission PSCs and 0 CSCs in the United States. Of the US population, 65.8% had 60-minute ground access to PSCs. After adding up to 20 optimally located CSCs per state, 63.1% of the US population had 60-minute ground access and 86.0% had 60-minute ground/air access to a CSC. Across states, median CSC access was 55.7% by ground (interquartile range 35.7%-71.5%) and 85.3% by ground/air (interquartile range 59.8%-92.1%). Ground access was lower in Stroke Belt states compared with non-Stroke Belt states (32.0% vs 58.6%, p = 0.02) and lower in states without emergency medical service routing policies (52.7% vs 68.3%, p = 0.04).

CONCLUSION

Optimal system simulation can be used to develop efficient care systems that maximize accessibility. Under optimal conditions, a large proportion of the US population will be unable to access a CSC within 60 minutes.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

Complication rates and center enrollment volume in the carotid revascularization endarterectomy versus stenting trial

BACKGROUND AND PURPOSE

Evidence indicates that center volume of cases affects outcomes for both carotid endarterectomy and stenting. We evaluated the effect of enrollment volume by site on complication rates in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST).

METHODS

The primary composite end point was any stroke, myocardial infarction, or death within 30 days or ipsilateral stroke in follow-up. The 477 approved surgeons performed >12 procedures per year with complication rates <3% for asymptomatic patients and <5% for symptomatic patients; 224 interventionists were certified after a rigorous 2 step credentialing process. CREST centers were divided into tertiles based on the number of patients enrolled into the study, with Group 1 sites enrolling <25 patients, Group 2 sites enrolling 25 to 51 patients, and Group 3 sites enrolling >51 patients. Differences in periprocedural event rates for the primary composite end point and its components were compared using logistic regression adjusting for age, sex, and symptomatic status within site-volume level.

RESULTS

The safety of carotid angioplasty and stenting and carotid endarterectomy did not vary by site-volume during the periprocedural period as indicated by occurrence of the primary end point (P=0.54) or by stroke and death (P=0.87). A trend toward an inverse relationship between center enrollment volume and complications was mitigated by adjustment for known risk factors.

CONCLUSIONS

Complication rates were low in CREST and were not associated with center enrollment volume. The data are consistent with the value of rigorous training and credentialing in trials evaluating endovascular devices and surgical procedures.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Association between hospital case volume and mortality in non-elderly pneumonia patients stratified by severity: a retrospective cohort study

Background

The characteristics and aetiology of pneumonia in the non-elderly population is distinct from that in the elderly population. While a few studies have reported an inverse association between hospital case volume and clinical outcome in elderly pneumonia patients, the evidence is lacking in a younger population. In addition, the relationship between volume and outcome may be different in severe pneumonia cases than in mild cases. In this context, we tested two hypotheses: 1) non-elderly pneumonia patients treated at hospitals with larger case volume have better clinical outcome compared with those treated at lower case volume hospitals; 2) the volume-outcome relationship differs by the severity of the pneumonia.

Methods

We conducted the study using the Japanese Diagnosis Procedure Combination database. Patients aged 18–64 years discharged from the participating hospitals between July to December 2010 were included. The hospitals were categorized into four groups (very-low, low, medium, high) based on volume quartiles. The association between hospital case volume and in-hospital mortality was evaluated using multivariate logistic regression with generalized estimating equations adjusting for pneumonia severity, patient demographics and comorbidity score, and hospital academic status. We further analyzed the relationship by modified A-DROP pneumonia severity score calculated using the four severity indices: dehydration, low oxygen saturation, orientation disturbance, and decreased systolic blood pressure.

Results

We identified 8,293 cases of pneumonia at 896 hospitals across Japan, with 273 in-hospital deaths (3.3%). In the overall population, no significant association between hospital volume and in-hospital mortality was observed. However, when stratified by pneumonia severity score, higher hospital volume was associated with lower in-hospital mortality at the intermediate severity level (modified A-DROP score = 2) (odds ratio (OR) of very low vs. high: 2.70; 95% confidence interval (CI): 1.12–6.55, OR of low vs. high: 2.40; 95% CI:0.99–5.83). No significant association was observed for other severity strata.

Conclusions

Hospital case volume was inversely associated with in-hospital mortality in non-elderly pneumonia patients with intermediate pneumonia severity. Our result suggests room for potential improvement in the quality of care in hospitals with lower volume, to improve treatment outcomes particularly in patients admitted with intermediate pneumonia severity.

Carotid Artery Stenting Versus Carotid Endarterectomy for Treatment of Asymptomatic Carotid Disease

In patients with asymptomatic carotid artery stenosis the optimal strategy to reduce the risk for stroke remains controversial. Although carotid endarterectomy was traditionally considered the gold standard for revascularization, emerging data suggest that carotid artery stenting is an appropriate alternative in many asymptomatic patients. This article summarizes the evidence base and related controversies regarding carotid endarterectomy versus carotid artery stenting for the revascularization of carotid disease in asymptomatic patients.

Surgical specialty and outcomes for carotid endarterectomy: evidence from the National Surgical Quality Improvement Program

BACKGROUND

Carotid endarterectomy (CEA) has been performed since the 1950s and remains one of the most common surgical procedures in the United States. The procedure is performed by cardiothoracic, general, neurologic, and vascular surgeons. This study uses data from the National Surgical Quality Improvement Program (NSQIP) to examine the outcomes after CEA when performed by general or vascular surgeons.

MATERIALS AND METHODS

Data included 34,493 CEAs from years 2005 to 2010 recorded in the NSQIP database. Primary outcomes measured were length of stay, 30-d mortality, surgical site infection, cerebrovascular accident, myocardial infarction, and blood transfusion requirement. Secondary outcomes measured were the remaining intraoperative outcomes from the NSQIP database.

RESULTS

After controlling for patient and surgical characteristics, patients treated by general surgeons did not have a significantly different LOS or 30-d mortality than those treated by vascular surgeons. Patients of general surgeons had nearly twice the risk of acquiring a surgical site infection (odds ratio [OR] = 1.94; P = 0.012), >1.5 times the risk of cerebrovascular accident (OR = 1.56; P = 0.008), and >1.8 times the risk of blood transfusion (OR = 1.85; P = 0.017) than those of vascular surgeons. Patients of general surgeons had less than half the risk of having a myocardial infarction (OR = 0.34; P = 0.031) than those of vascular surgeons.

CONCLUSIONS

Surgical specialty is associated with a wide range of postoperative outcomes after CEA. Additional research is needed to explore practice and cultural differences across surgical specialty that may lead to outcome differences.