Superior 3-Year Value of Open and Endovascular Repair of Abdominal Aortic Aneurysm with High-Volume Providers

Surgeon volume and outcomes following thoracic endovascular aortic repair for blunt thoracic aortic injury

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI) at high-volume hospitals has previously been associated with lower perioperative mortality, but the impact of annual surgeon volume on outcomes following TEVAR for BTAI remains unknown.

METHODS

We analyzed Vascular Quality Initiative (VQI) data from patients with BTAI that underwent TEVAR between 2013 and 2023. Annual surgeon volumes were computed as the number of TEVARs (for any pathology) performed over a 1-year period preceding each procedure and were further categorized into quintiles. Surgeons in the first volume quintile were categorized as low volume (LV), the highest quintile as high volume (HV), and the middle three quintiles as medium volume (MV). TEVAR procedures performed by surgeons with less than 1-year enrollment in the VQI were excluded. Using multilevel logistic regression models, we evaluated associations between surgeon volume and perioperative outcomes, accounting for annual center volumes and adjusting for potential confounders, including aortic injury grade and severity of coexisting injuries. Multilevel models accounted for the nested clustering of patients and surgeons within the same center. Sensitivity analysis excluding patients with grade IV BTAI was performed.

RESULTS

We studied 1321 patients who underwent TEVAR for BTAI (28% by LV surgeons [0-1 procedures per year], 52% by MV surgeons [2-8 procedures per year], 20% by HV surgeons [≥9 procedures per year]). With higher surgeon volume, TEVAR was delayed more (in <4 hours: LV: 68%, MV: 54%, HV: 46%; P < .001; elective (>24 hours): LV: 5.1%; MV: 8.9%: HV: 14%), heparin administered more (LV: 80%, MV: 81%, HV: 87%; P = .007), perioperative mortality appears lower (LV: 11%, MV: 7.3%, HV: 6.5%; P = .095), and ischemic/hemorrhagic stroke was lower (LV: 6.5%, MV: 3.6%, HV: 1.5%; P = .006). After adjustment, compared with LV surgeons, higher volume surgeons had lower odds of perioperative mortality (MV: 0.49; 95% confidence interval [CI], 0.25-0.97; P = .039; HV: 0.45; 95% CI, 0.16-1.22; P = .12; MV/HV: 0.50; 95% CI, 0.26-0.96; P = .038) and ischemic/hemorrhagic stroke (MV: 0.38; 95% CI, 0.18-0.81; P = .011; HV: 0.16; 95% CI, 0.04-0.61; P = .008). Sensitivity analysis found lower adjusted odds for perioperative mortality (although not significant) and ischemic/hemorrhagic stroke for higher volume surgeons.

CONCLUSIONS

In patients undergoing TEVAR for BTAI, higher surgeon volume is independently associated with lower perioperative mortality and postoperative stroke, regardless of hospital volume. Future studies could elucidate if TEVAR for non-ruptured BTAI might be delayed and allow stabilization, heparinization, and involvement of a higher TEVAR volume surgeon.

Long-term value in open and endovascular repair of chronic mesenteric ischemia

OBJECTIVE

Guidelines recommend open revascularization (OR) over endovascular revascularization (ER) for the treatment of chronic mesenteric ischemia (CMI) for younger, healthier patients. However, little is known about the long-term costs of these recommendations with respect to patients' overall life expectancy. This study investigated whether 5-year value differs between these treatment modalities.

METHODS

Patient data were extracted from the Statewide Planning and Research Cooperative System, the New York statewide all-payor database containing demographics, diagnoses, treatments, and charges. The database was queried for patients with an International Classification of Diseases, ninth revision, code for CMI, with the specific exclusion of acute ischemia cases. A propensity score match was performed using the Charlson Comorbidity Index, age, sex, race, renal status, and pulmonary disease for the final cohort of patients. Multiple linear regression and mixed effects linear regression were used to determine factors associated with 5-year value, calculated as life-years/$100k in charges. Charges were gathered from the index admission and subsequent admissions for acute or CMI, mesenteric angiography, or follow-up reintervention. Kaplan-Meier estimation was performed for survival and reintervention-free survival.

RESULTS

From 2000 to 2014, 875 patients underwent intervention for CMI. Of those meeting inclusion criteria, 209 (28.1%) underwent OR and 535 (71.9%) ER. After propensity score matching (n = 209 in each group), the ER group showed higher value at 5 years after the procedure (8.04 ± 11.42 life-years/$100k charges vs 4.89 ± 5.28 life-years/$100k charges; P < .01). More patients underwent reintervention in the ER group (37 patients vs 17 patients; P < .01), with 55 reinterventions in the ER group and 19 in the OR group (P < .01). Multiple linear regression analysis showed that age, congestive heart failure, dysrhythmia, cancer, and days spent in the intensive care unit were negatively associated with value at 5 years, whereas ER was positively associated. Survival was 59.6 ± 3.76% vs 62.3% ± 3.49% at 5 years (P = .91), and reintervention-free survival was 43.7 ± 3.86% vs 58.1 ± 3.53% (P = .04), for ER and OR respectively.

CONCLUSIONS

Despite increased reinterventions and lower reintervention-free survival, the value for patients with CMI was higher in those who underwent ER in the largest propensity score-matched cohort to date looking at long-term value. Factors negatively associated with value were OR, age, days in intensive care, congestive heart failure, dysrhythmia, and cancer. In patients with amenable anatomy, ER is validated as the first-choice treatment for CMI based on the superior procedural value.

Survival, Reintervention, and Value of Open and Endovascular Repair for Chronic Mesenteric Ischemia

BACKGROUND

There are limited analyses of survival and postoperative outcomes in chronic mesenteric ischemia (CMI) using data from large cohorts. Current guidelines recommend open repair (OR) for younger, healthier patients when long-term benefits outweigh increased perioperative risks or for poor endovascular repair (ER) candidates. This study investigates whether long-term survival, reintervention, and value differ between these treatment modalities.

METHODS

A retrospective cohort analysis was performed on data extracted from the Statewide Planning and Research Cooperative System, the New York statewide all-payer database containing demographics, diagnoses, treatments, and charges. Patients were selected for CMI and subsequent ER or OR using International Classification of Diseases, Ninth Revision codes. Patients with peripheral arterial disease were excluded to account for ambiguity in the International Classification of Diseases, Ninth Revision procedure code for angioplasty of noncoronary vessels, which includes angioplasty of upper and lower extremity vessels. Kaplan-Meier analysis was used to compare 1-year and 5-year survival and reintervention between treatment modalities using a propensity-matched cohort. Cox proportional hazards testing was performed to find factors associated with 1-year and 5-year survival and reintervention. Analysis of procedural value was performed using linear regression.

RESULTS

From 2000 to 2014, 744 patients met inclusion criteria. Of these, 209 (28.1%) underwent OR and 535 (71.9%) ER. No difference between propensity-matched groups was found in 1-year (P = 0.46) or 5-year (P = 0.91) survival. Congestive heart failure (hazard ratio [HR]: 2.8, 95% confidence interval [CI]: 1.7-4.4; P < 0.01), cancer (HR: 2.8, 95% CI: 1.3-5.8; P < 0.01), and dysrhythmia (HR: 1.8, 95% CI: 1.1-2.8; P = 0.02) correlated with 1-year mortality. Cancer (HR: 2.9, 95% CI: 1.6-5.5; P < 0.01), congestive heart failure (HR: 2.2, 95% CI: 1.5-3.2; P < 0.01), chronic pulmonary disease (HR: 1.4, 95% CI: 1.0-2.0; P = 0.04), and age (HR: 1.03, 95% CI: 1.01-1.05; P < 0.01) correlated with 5-year mortality. Treatment modality was not associated with reintervention at 1 year on Kaplan-Meier analysis (P = 0.29). However, ER showed increased instances of reintervention at 5 years (P < 0.01). Additionally, ER was associated with an increased 5-year value (0.7 ± 0.9 vs. 0.5 ± 0.5 life years/charges at index admission [$10k], P < 0.01; b coefficient: 0.2, 95% CI: 0.1-0.4, P < 0.01).

CONCLUSIONS

This is the largest retrospective propensity-matched single-study cohort to analyze long-term survival outcomes after intervention for CMI. Long-term mortality was independent of treatment modality and rather was associated with patient comorbidities. Therefore, treatment selection should depend on anatomic considerations and long-term value. ER should be considered over OR in patients with amenable anatomy based on the superior procedural value.

Guideline Compliant Minimum Asymptomatic Carotid Endarterectomy Surgeon and Hospital Volume Cutoffs

BACKGROUND

There is a known association between volume and outcomes after carotid endarterectomy (CEA). A recent analysis suggested rates of stroke and death do not significantly reduce after a surgeon volume cutoff of 20 CEAs per year. However, these results would severely limit access. The objective here is to identify a lower optimal cutpoint for surgeon and hospital volume for asymptomatic CEA.

METHODS

We evaluated asymptomatic CEA patients using The New York Statewide Planning and Research Cooperative System database from 2000-2014. The relationship of 3-year averaged volumes for surgeons and hospitals to 30-day stroke was assessed using multiple logistic regression and included both hospital and surgeon volume in all analyses. Optimized cut points were the lowest significant volume cutoff that minimized the adjusted odds ratio of stroke.

RESULTS

We studied 32,549 CEAs performed by 271 surgeons in 136 centers by vascular surgeons. The median surgeon volume was 26.3 (interquartile range: 12.3-51.7) and the median hospital volume was 67 (interquartile range: 36.3-119.3). The surgeon volume cut point was 3 and the hospital volume cut point was 6 cases per year. There were 756 (2.3%) procedures performed by surgeons with a volume < 3 and 560 (1.7%) procedures performed by hospitals with a volume < 6. Perioperative stroke and death rates were 2.0% (95% confidence interval [CI]: 1.8-2.1) and 3.8% (95% CI: 2.6-5.5) for an average yearly surgeon volume ≥ 3 and < 3 (P = 0.070), respectively. The combined stroke and death rate was 2.0% (95% CI: 1.8-2.1) and 4.8% (95% CI: 3.2-7.0) for an average yearly center volume ≥ 6 and < 6 (P = 0.007), respectively. A combined surgeon and hospital volume variable also predicted outcomes and low-volume procedures did not meet previously proposed American Heart Association and Society for Vascular Surgery quality measures.

CONCLUSIONS

These data demonstrate an improvement in outcomes at a lower volume threshold than previously reported. These modest cutoff values should be used for asymptomatic CEA volume guideline formation and for future studies, after accounting for the impact of other important factors that may be driving volume-outcome relationships in asymptomatic CEA.

Higher Surgeon Volume is Associated with Lower Odds of Complication Following TEVAR for Aortic Dissections

OBJECTIVE

This study aimed to understand the impact of surgeon volume on outcomes of thoracic endovascular aortic repair (TEVAR) in patients being treated for aortic dissection.

METHODS

Patients undergoing TEVAR from January 2014 - March 2021 in the Vascular Quality Initiative (VQI) database were analyzed. Patients with aortic dissection who underwent TEVAR were divided into quartiles based on the annual TEVAR volume of their vascular surgeon. The highest quartile, middle two quartiles, and lowest quartile were deemed high volume (HV), moderate volume (MV), and low volume (LV), respectively. Multivariable logistic regressions were performed to compare cohort outcomes in terms any postoperative complication, stroke, spinal cord ischemia, reintervention, and 30-day mortality. A Cox proportional hazard model was used to assess the hazard of overall postoperative mortality.

RESULTS

Amongst 1,217 patients undergoing TEVAR, 321, 621, and 275 were performed by HV, MV, and LV surgeons, respectively. HV performed >19 annual TEVARs, MV surgeons between 5 and 18, and LV surgeons ≤4. Adjusted odds of any postoperative complication revealed that HV and MV surgeons had lower odds of overall postoperative complications [(OR 0.58, (95% CI 0.30 - 0.85), p = 0.011) and (OR 0.60, (95% CI 0.38 - 0.87), p = 0.008)], respectively when compared to LV patients. HV had lower odds of respiratory complications than LV surgeons complications [(OR 0.42, (95% CI 0.17 - 0.93), p = 0.039)]. Adjusted analysis of outcomes including spinal cord ischemia, stroke, myocardial infarction, 30-day mortality, and overall mortality did not reveal statistically significant differences between cohorts.

CONCLUSION

Surgeon volume does not to impact 30-day mortality or long-term mortality after TEVAR for aortic dissection, but the odds of overall postoperative complications were lower for HV and MV surgeons when compared to LV surgeons.

Surgeon volume and established hospital perioperative mortality rate together predict for superior outcomes after open abdominal aortic aneurysm repair

BACKGROUND

In 2018, the Society for Vascular Surgery (SVS) published hospital volume guidelines for elective open abdominal aortic aneurysm (AAA) repair, recommending that elective open surgical repair of AAAs should be performed at centers with an annual volume of ≥10 open aortic operations of any type and a documented perioperative mortality of ≤5%. Recent work has suggested a yearly surgeon volume of at least seven open aortic cases for improved outcomes. The objective of the present study was to assess the importance of hospital volume and surgeon volume at these cut points for predicting 1-year mortality after open surgical repair of AAAs.

METHODS

We evaluated patients who had undergone elective open AAA repair using the New York Statewide Planning and Research Cooperative System database from 2003 to 2014. The effect of the SVS guidelines on postoperative mortality and complications was evaluated. Confounding between the hospital and surgeon volumes was identified using mixed effects multivariate Cox proportional hazards analysis. The effect of the interactions between hospital volume, established hospital perioperative survival, and surgeon volume on postoperative outcomes was also investigated.

RESULTS

The cohort consisted of 7594 elective open AAA repairs performed by 542 surgeons in 137 hospitals during the 12-year study period. Analysis of the 2018 guidelines using the Statewide Planning and Research Cooperative System database revealed 1-year and 30-day mortality rates of 9.2% (range, 8.3%-10.1%) and 3.5% (range, 2.9%-4.1%) for centers that were within the SVS guidelines and 13.6% (range, 12.5%-14.7%) and 6.9% (range, 6.1%-7.8%) for those that were outside the guidelines, respectively (P < .001 for both). Multivariate survival analysis revealed a hazard ratio for a surgeon volume of ≥7, hospital volume of ≥10, and hospital 3-year perioperative mortality of ≤5% of 0.80 (95% confidence interval [CI], 0.70-0.93; P = .003), 0.91 (95% CI, 0.77-1.08; P = .298), and 0.72 (95% CI, 0.62-0.82; P < .001), respectively. Additionally, procedures performed by surgeons with a yearly average volume of open aortic operations of at least seven and at hospitals with an established elective open AAA repair perioperative mortality rate of ≤5% showed improved 1-year (33.2% relative risk reduction; P < .001) and 30-day (P = .001) all-cause survival and improved postoperative complication rates.

CONCLUSIONS

These data have demonstrated that centers that meet the SVS AAA volume guidelines are associated with improved 1-year and 30-day all-cause survival. However, the results were confounded by surgeon volume. A surgeon open aortic volume of at least seven procedures and an established hospital perioperative mortality of ≤5% each independently predicted for 1-year survival after open AAA repair, with the hospital volume less important. These results indicate that surgeons with an annual volume of at least seven open aortic operations of any type should perform elective open AAA repair at centers with a documented perioperative mortality of ≤5%.

A systematic review of the effect of surgeon and hospital volume on survival in aortic, thoracic and fenestrated endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) is becoming a mainstay in vascular surgery, both in metropolitan and regional hospitals. This review aims to assess the impact of hospital and surgeon volume on perioperative mortality specific to this surgery type to support the use of this treatment modality extensively.

METHODS

A literature search was performed on multiple dedicated medical databases using a detailed search strategy with terms focusing on hospital volume and EVARs. Inclusion and exclusion criteria were used to screen and evaluate suitable sources, focusing on operators and hospitals performing EVARs and the morbidity/mortality as outcomes. The results were then appraised using a PRISMA framework.

RESULTS

We reviewed 45 articles. Twelve articles met inclusion criteria for complete review. There was no level 1 evidence, and only a single systematic review and meta-analysis. EVAR and thoracic EVAR perioperative mortality had no correlation with hospital volume. Limited evidence was presented for fenestrated EVAR, where a mortality risk based on hospital volume remains unanswered. Open procedures for aneurysm repair had perioperative mortality outcomes that grossly correlated with hospital volume, supporting their use in high-volume centers.

CONCLUSIONS

With open aneurysm repairs having an increased mortality risk in low-volume centers, and endovascular treatment options gaining momentum, there is considerable support for the use of EVAR and thoracic EVAR in smaller regional centers safely and effectively. There is very limited evidence in the use of fenestrated EVAR, which remains unanswered, but presents a significant opportunity for research.

Association between operation volume and postoperative mortality in the elective open repair of infrarenal abdominal aortic aneurysms: systematic review

Background

An inverse association between the case volume per hospital and surgeon and perioperative mortality has been shown for many surgical interventions. There are numerous studies on this issue for the open treatment of infrarenal aortic aneurysms.

Aim

To present the available data on the association between the case volume per hospital and surgeon and perioperative mortality in the elective open repair of infrarenal aortic aneurysms in a systematic review.

Materials and methods

Using the PubMed, Cochrane Library, Web of Science Core Collection, CINAHL, Current Contents Medicine (CCMed), and ClinicalTrials.gov databases, a systematic search was performed using defined keywords. From the search results, all original papers were included that compared the elective open repair of an infrarenal aortic aneurysm in a “high volume” center with a “low volume” center or by a “high volume” surgeon with a “low volume” surgeon, as defined in the respective study.

Results

After deduplication, the literature search yielded 1021 hits of which 60 publications met the inclusion criteria. Of these, 37/43 studies showed a lower mortality in “high volume” compared to “low volume” centers and 14/17 comparisons showed a lower mortality for “high volume” compared to “low volume” surgeons. The effect measures, usually odds ratios, ranged from 0.37 to 0.99 for volume per hospital and 0.31 to 0.92 for volume per surgeon. Regarding the threshold values for the definition of “high volume” and “low volume,” a clear heterogeneity was shown between the individual studies.

Discussion

The available data on the association between the case volume per hospital and surgeon and perioperative mortality in the elective open repair of infrarenal aortic aneurysms show that interventions performed in “high volume” centers or by “high volume” surgeons are associated with lower mortality. To ensure the best possible outcome in terms of low perioperative mortality in the open repair of infrarenal aortic aneurysms, the aim should be centralization with high case volume per hospital and surgeon.

A Nationwide Study Assessing Preventable Hospitalization Rate on Mortality After Major Cardiovascular Surgery

Despite the use of various factors to measure hospital quality, most measures have not resulted in long-term improvements in patient outcomes. This study's purpose is to determine the effect of a previously unassessed measure of quality of care-a hospital's preventable hospitalization rate-on 30-day mortality at both the hospital and individual levels after three major cardiovascular surgery procedures. This is a population-based study using Taiwan's National Health Insurance database. We retrieved data from 2001 to 2014 for patients who had undergone abdominal aortic aneurysm (AAA) repair, coronary artery bypass graft, or aortic valve replacement (AVR). Preventable hospitalizations are hospitalizations for 11 chronic conditions that are considered preventable with effective primary care. The outcome was 30-day surgical mortality. Our dataset contained 65,863 patients who had undergone surgery for one of the three cardiovascular procedures. Preventable hospitalization rate was significantly associated with higher hospital mortality rates for all procedures. At the patient level, the adjusted odds of mortality after AAA repair were increased 55% (P < 0.01) for every 2% increase in the preventable hospitalization rate. For coronary artery bypass graft, preventable hospitalization was not a significant predictor of mortality, but rather patient factors and surgeon factors were significant. For AVR, the adjusted odds of mortality were increased 7% (P < 0.01) for every 1% increase in preventable hospitalization rate. High preventable hospitalization rate may serve as a hospital quality measure that could signal increased odds of mortality for selected cardiovascular procedures, especially for higher risk-lower volume procedures such as AAA repair and AVR.

One-year patient survival correlates with surgeon volume after elective open abdominal aortic surgery

OBJECTIVE

Volume-outcome relationships in surgery have been well established. Studies have shown that high-volume surgeons provide improved outcomes in performing open abdominal aneurysm repairs. The hypothesis of this study was that high-volume surgeons provide superior short-term and midterm outcomes of elective open aortic operations compared with low-volume surgeons.

METHODS

We evaluated patients undergoing elective open abdominal aortic aneurysm repair, aortofemoral bypass, and aortomesenteric bypass by board-certified vascular surgeons using the New York Statewide Planning and Research Cooperative System database from 2002 to 2014. The Contal and O'Quigley technique was used to estimate a cut point objectively and provided an estimate of significance. A division using average yearly volumes (averaged during 3 years) of seven or more cases and fewer than seven cases per year returned the highest Q statistic, and this grouping was used to classify high-volume and low-volume provider groups. Rates of complications during index hospitalization, length of stay, 30-day survival, 90-day survival, 1-year survival, and cause of death were analyzed using mixed effect models.

RESULTS

In 118 hospitals during the 13-year period, 266 board-certified vascular surgeons performed 244 aortomesenteric bypasses, 4202 aortofemoral bypasses, and 6126 abdominal aortic aneurysm repairs. High-volume surgeons' rates of complications during index hospitalization, 30-day survival, 90-day survival, and 1-year survival were superior to those of low-volume surgeons. The Contal and O'Quigley technique returned an estimate of seven operations per year for optimal survival during 1 year. This cutoff is associated with an adjusted 1-year hazard ratio of 0.687 (P = .003), a 2.69% difference in 1-year all-cause survival (P = .003), and a 1.76-day reduction in the mean length of stay at index hospitalization (P < .001). Higher volume surgeons showed a 25.0%, 43.4%, 42.4%, 40.6%, and 45.0% reduction in postoperative rates of acute renal failure (P < .001), hemorrhage (P < .001), pulmonary failure (P < .001), sepsis (P < .001), and venous thromboembolism (P < .001), respectively. Abdominal abscess, acute renal failure, hemorrhage, myocardial infarction, and sepsis were associated with increased cardiovascular cause-specific mortality after open aortic operations (P < .001).

CONCLUSIONS

These data demonstrate that high-volume surgeons performing elective open aortic operations provide reduced complications and improved short-term and midterm survival compared with low-volume surgeons. Clinical and postoperative variables that are associated with increased cardiovascular cause-specific mortality are also identified. These data provide further evidence that elective open abdominal vascular surgery should be centralized to high-volume surgeons.