Dynamic volume-outcome association for esophagectomies: Do current volume thresholds still apply?

BACKGROUND

It is unknown if the current minimum case volume recommendation of 20 cases per year per hospital is applicable to contemporary practice.

METHODS

Patients undergoing esophageal resection between 2005 and 2015 were identified in the National Cancer Database. High, medium, and low-volume hospital strata were defined by quartiles. Adjusted odds ratios and adjusted 30-day mortality between low-, medium-, and high-volume hospitals were calculated using logistic regression analyses and trended over time.

RESULTS

Only 1.1% of hospitals had ≥20 annual cases. The unadjusted 30-day mortality for esophagectomy was 3.8% overall. Unadjusted and adjusted 30-day mortality trended down for all three strata between 2005 and 2015, with disproportionate decreases for low-volume and medium-volume versus high-volume hospitals. By 2015, adjusted 30-day mortality was similar in medium- and high-volume hospitals (odds ratio 1.35, 95% confidence interval 0.96-1.91). For hospitals with 20 or more annual cases the adjusted 30-day mortality was 2.7% overall. To achieve this same 30-day mortality the minimum volume threshold had lowered to 7 annual cases by 2015.

CONCLUSION

Only 1.1% of hospitals meet current volume recommendations for esophagectomy. Differential improvements in postoperative mortality at low- and medium- versus high-volume hospitals have led to 7 cases in 2015 achieving the same adjusted 30-day mortality as 20 cases in the overall cohort. Lowering volume thresholds for esophagectomy in contemporary practice would potentially increase the proportion of hospitals able to meet volume standards and increase access to quality care without sacrificing quality.

Effect of General Surgery Resident Participation in Thoracic Surgery on Oncologic Outcomes: An Observational Cohort Study

Background: Despite increasing sub-specialization, general surgeons continue to perform oncologic thoracic surgeries. Our objective was to determine whether general surgery resident participation in thoracic surgery affects surgical quality or oncologic outcomes. We hypothesized that patient outcomes with and without resident participation would be similar. Methods: We retrospectively reviewed the electronic health records of patients with stage 0-IV lung cancer undergoing oncologic pulmonary resection at BLINDED FOR REVIEW during an 11-year period (2012-2022). Patients younger than 18 years or older than 85 years were excluded, as were those who had incomplete follow-up data or were unregistered in our institutional cancer registry. Patients were divided into groups based on whether residents or staff surgeons completed >50% of the critical portions of the operation. We compared 30-day morbidity outcomes, overall survival (OS), and disease-free survival (DFS). Results: Three hundred thirteen patients met inclusion criteria. Demographic and clinical characteristics were similar between groups, as were types of surgical resection and median operative times. A statistical difference was found in the distribution of surgical approach. The odds of morbidity were 65% higher in the Staff group (OR=1.65; 95% CI, 1.007-2.71). Resident participation was not significantly associated with OS or DFS (P =.32 and P =.54, respectively). Discussion: General surgery resident involvement in lung cancer operations is not associated with longer operative times but is associated with a higher likelihood of a thoracotomy. General surgery resident involvement was associated with decreased postoperative morbidity and did not significantly affect OS or DFS.

Effect of institution volume on mortality and outcomes in osteoporotic hip fracture care

Hospitals that treat more patients with osteoporotic hip fractures do not generally have better care outcomes than those that treat fewer hip fracture patients. Institutions that do look after more such patients tend, however, to more consistently perform relevant health assessments.

INTRODUCTION

An inveterate link has been found between institution case volume and a wide range of clinical outcomes; for a host of medical and surgical conditions. Hip fracture patients, notwithstanding the significance of this injury, have largely been overlooked with regard to this important evaluation.

METHODS

We used the UK National Hip Fracture database to determine the effect of institution hip fracture case volume on hip fracture healthcare outcomes in 2019. Using logistic regression for each healthcare outcome, we compared the best performing 50 units with the poorest performing 50 institutions to determine if the unit volume was associated with performance in each particular outcome.

RESULTS

There were 175 institutions with included 67,673 patients involved. The number of hip fractures between units ranged from 86 to 952. Larger units tendered to perform health assessments more consistently and mobilise patients more expeditiously post-operatively. However, patients treated at large institutions did not have any shorter lengths of stay. With regard to most other outcomes there was no association between the unit number of cases and performance; notably mortality, compliance with best practice tariff, time to surgery, the proportion of eligible patients undergoing total hip arthroplasty, length of stay delirium risk and pressure sore risk.

CONCLUSIONS

There is no relationship between unit volume and the majority of health care outcomes. It would seem that larger institutions tend to perform better at parameters that are dependent upon personnel numbers. However, where the outcome is contingent, even partially, on physical infrastructure capacity, there was no difference between larger and smaller units.

Volume-outcome relationship in intra-abdominal robotic-assisted surgery: a systematic review

As robotic-assisted surgery (RAS) expands to smaller centres, platforms are shared between specialities. Healthcare providers must consider case volume and mix required to maintain quality and cost-effectiveness. This can be informed, in-part, by the volume-outcome relationship. We perform a systematic review to describe the volume-outcome relationship in intra-abdominal robotic-assisted surgery to report on suggested minimum volumes standards. A literature search of Medline, NICE Evidence Search, Health Technology Assessment Database and Cochrane Library using the terms: "robot*", "surgery", "volume" and "outcome" was performed. The included procedures were gynecological: hysterectomy, urological: partial and radical nephrectomy, cystectomy, prostatectomy, and general surgical: colectomy, esophagectomy. Hospital and surgeon volume measures and all reported outcomes were analysed. 41 studies, including 983,149 procedures, met the inclusion criteria. Study quality was assessed using the Newcastle-Ottawa Quality Assessment Scale and the retrieved data was synthesised in a narrative review. Significant volume-outcome relationships were described in relation to key outcome measures, including operative time, complications, positive margins, lymph node yield and cost. Annual surgeon and hospital volume thresholds were described. We concluded that in centres with an annual volume of fewer than 10 cases of a given procedure, having multiple surgeons performing these procedures led to worse outcomes and, therefore, opportunities should be sought to perform other complimentary robotic procedures or undertake joint cases.

Mortality factors in pancreatic surgery: A systematic review. How important is the hospital volume?

BACKGROUND

How the extent of confounding adjustment impact (hospital) volume-outcome relationships in published studies on pancreatic cancer surgery is unknown.

METHODS

A systematic literature search was conducted for studies that investigated the relationship between volume and outcome using a risk adjustment procedure by querying the following databases: PubMed, Cochrane Central Register of Controlled Trials, Livivo, Medline and the International Clinical Trials Registry Platform (last query: 2020/09/16). Importance of risk-adjusting covariates were assessed by effect size (odds ratio, OR) and statistical significance. The impact of covariate adjustment on hospital (or surgeon) volume effects was analyzed by regression and meta-regression models.

RESULTS

We identified 87 studies (75 based on administrative data) with nearly 1 million patients undergoing pancreatic surgery that included in total 71 covariates for risk adjustment. Of these, 33 (47%) had statistically significant effects on short-term mortality and 23 (32%) did not, while for 15 (21%) factors neither effect size nor statistical significance were reported. The most important covariates for short term mortality were patient-specific factors. Concerning the covariates, single comorbidities (OR: 4.6, 95% CI: 3.3 to 6.3) had the strongest impact on mortality followed by hospital volume (OR: 2.9, 95% CI: 2.5 to 3.3) and the procedure (OR: 2.2, 95% CI: 1.9 to 2.5). Among the single comorbidities, coagulopathy (OR: 4.5, 95% CI: 2.8 to 7.2) and dementia (OR: 4.2, 95% CI: 2.2 to 8.0) had the strongest influence on mortality. The regression analysis showed a significant decrease hospital volume effect with an increasing number of covariates considered (OR: 0.06, 95% CI: 0.10 to -0.03, P < 0.001), while such a relationship was not observed for surgeon volume (P = 0.35).

CONCLUSIONS

This analysis demonstrated a significant inverse relationship between the extent of risk adjustment and the volume effect, suggesting the presence of unmeasured confounding and overestimation of volume effects. However, the conclusions are limited in that only the number of included covariates was considered, but not the effect size of the non-included covariates.

Trends in Textbook Outcomes over Time: Are Optimal Outcomes Following Complex Gastrointestinal Surgery for Cancer Increasing?

BACKGROUND

The use of composite measures like "textbook outcome" (TO) may provide a more accurate measure of surgical quality. We sought to determine if TO has improved over time and to characterize the association of achieving a TO with trends in survival among patients undergoing complex gastrointestinal surgery for cancer.

METHODS

Medicare beneficiaries who underwent pancreas, liver, or colon resection for a cancer diagnosis between 2004 and 2016 were identified using the SEER-Medicare database. Rates of TO (no complication, extended length of stay, 90-day readmission, or 90-day mortality) were assessed over time.

RESULTS

Among 94,329 patients, 6765 (7.2%), 1985 (2.1%), and 85,579 (90.7%) patients underwent resection for primary pancreatic, hepatic, or colon cancer, respectively. In total, 53,464 (56.7%) patients achieved a TO; achievement of TO varied by procedure (pancreatectomy: 48.1% vs. hepatectomy: 55.2% vs. colectomy: 57.4%, p < 0.001). The proportion of patients achieving a textbook outcome increased over time for all patients (2004-2007, 53.3% vs. 2008-2011, 56.5% vs. 2012-2016, 60.1%) (5-year increase: OR 1.16 95%CI 1.13-1.18) (p < 0.001). Survival at 1-year following pancreatic, liver, or colon resection for cancer had improved over time among both patients who did and did not achieve a postoperative TO. TO was independently associated with a marked reduction in hazard of death (HR 0.44, 95%CI 0.43-0.45). The association of TO and survival was consistent among patients stratified by procedure.

CONCLUSION

Less than two-thirds of patients undergoing complex gastrointestinal surgery for a malignant indication achieved a TO. The likelihood of achieving a TO increased over time and was associated with improved survival.

The impact of hospital volume on racial disparities in resected rectal cancer

BACKGROUND

Although high volume centers (HVC) equate to improved outcomes in rectal cancer, the impact of surgical volume related to race is less defined.

METHODS

Patients who underwent surgical resection for stage I-III rectal adenocarcinoma were divided into cohorts based on race and hospital surgical volume. Outcomes were analyzed following 1:1 propensity-score matching using logistic, Poisson, and Cox regression analyses with marginal effects.

RESULTS

Fifty-four thousand one hundred and eighty-four (91.5%) non-Black and 5043 (8.5%) Black patients underwent resection of rectal cancer. Following 1:1 matching of non-Black (N = 5026) and Black patients, 5-year overall survival (OS) of Black patients was worse (72% vs. 74.4%, average marginal effects [AME] 0.66, p = 0.04) than non-Black patients. When compared to non-Black patients managed at HVCs, Black patients had worse OS (70.1% vs. 74.7%, AME 1.55, p = 0.03), but this difference was not significant when comparing OS between non-Black and Black patients managed at HVCs (72.3% vs. 74.7%, AME 0.62, p = 0.06). Length of stay was longer among Black and HVC patients across all cohorts. There was no difference across cohorts in 90-day mortality.

CONCLUSIONS

Although racial disparities exist in rectal cancer, this disparity appears to be ameliorated when patients are managed at HVCs.

Does the Volume-Outcome Association in Pancreas Cancer Surgery Justify Regionalization of Care? A Review of Current Controversies

INTRODUCTION

Increasing hospital or surgeon volume is associated with improved outcomes among patients with pancreatic cancer. Promotion of regionalized care is based on this volume-outcome association. However, other research has exposed nuances and complexities inherent to this association that should be considered when promoting regionalized care models. We herein provide a critical review of the literature on the volume-outcome association and a discussion of areas of ongoing controversy.

METHODS

A PubMed literature search was conducted for the years 1995-2020. Peer reviewed original research studies were selected for critical review based on study design, potential to draw meaningful conclusions from the data, and discussion of current knowledge gaps.

RESULTS

Based on the cumulative published literature, hospital/surgeon volume and patient mortality are inversely related. However, it remains unclear whether volume is a proxy for other more causative variables inherent in high-volume centers. Interpretation of the volume-outcome association is made more difficult to interpret due to the large variation in the definition of high volume, difficulty in isolating the individual impact of surgeon versus hospital volume, challenges in quantifying health system processes related to volume, and the fact that some low-volume centers consistently achieve excellent clinical results. Implementation of true regionalized care models has been rare, likely reflecting both health system and patient level challenges.

CONCLUSION

The volume-outcome association has been consistently demonstrated to be important to the care of patients with pancreas cancer. The underlying mechanism of this association to explain the overall benefit is likely multifactorial. Better understanding of what drives the volume-outcome association may increase access to optimized care for a broader range of hospital systems and patients.

Identifying the Optimal case-volume threshold for pancreatectomy in contemporary practice

BACKGROUND

The volume-mortality association led to regionalization recommendations for pancreatic surgery. Mortality following pancreatectomy has declined, but case-volume thresholds remain unchanged.

METHODS

Patients undergoing pancreatectomy from 2004 to 2013 were identified in the National Cancer Database (NCDB). Hospitals were divided into low (LV), medium (MV), and high-volume (HV) strata using 30-day mortality quartiles and logistic regression with cubic splines. Adjusted absolute difference and odds of 30-day mortality between strata were calculated.

RESULTS

Annual volumes for LV, MV, and HV were <4, 4-18 and > 18 cases using quartiles and <6, 6-18 and > 18 using cubic splines. Absolute 30-day mortality trended downwards, with differential improvements for MV and LV. Benchmark 30-day mortality for hospitals with >18 cases was 2.8%. For this benchmark, the case-volume threshold decreased from 31 in 2004 to 6 in 2013.

CONCLUSION

Differential improvement in 30-day mortality at LV and MV hospitals led to similar 30-day mortality odds at MV and HV hospitals by 2013.

Are Volume Pledge Standards Worth the Travel Burden for Major Abdominal Cancer Operations?

OBJECTIVE

The study objective is to determine the association between travel distance and surgical volume on outcomes after esophageal, pancreatic, and rectal cancer resections.

SUMMARY OF BACKGROUND DATA

"Take the Volume Pledge" aims to centralize esophagectomies, pancreatectomies, and proctectomies to hospitals meeting minimum volume standards. The impact of travel, and possible care fragmentation, on potential benefits of centralized surgery is not well understood.

METHODS

Using the National Cancer Database (2004-2016), patients who underwent esophageal, pancreatic, or rectal resections at far HVH meeting volume standards versus local intermediate (IVH) and low-volume (LVH) hospitals were identified. Perioperative outcomes and 5-year OS were compared.

RESULTS

Of 49,454 patients, 17,544 (34.5%) underwent surgery at far HVH, 11,739 (23.7%) at local IVH, and 20,171 (40.8%) at local LVH. The median (interquartile range) travel distances were 77.1 (51.1-125.4), 13.2 (5.8-27.3), and 7.8 (3.1-15.5) miles to HVH, IVH, and LVH, respectively. By multivariable analysis, LVH was associated with increased 30-day mortality for all resections compared to HVH, but IVH was associated with mortality only for proctectomies [odds ratio 1.90, 95% confidence interval (CI) 1.31-2.75]. Compared to HVH, both IVH (hazard ratio 1.25, 95% CI 1.19-1.31) and LVH (hazard ratio 1.35, 95% CI 1.29-1.42) were associated with decreased 5-year OS.

CONCLUSIONS

Compared to far HVH, 30-day mortality was higher for all resections at LVH, but only for proctectomies at IVH. Five-year OS was consistently worse at local LVH and IVH. Improving long-term outcomes at IVH may provide opportunities for greater access to quality cancer care.

Safe implementation of minimally invasive pancreas resection: a systematic review

BACKGROUND

Minimally invasive pancreas resection (MIPR) has been expanding in the past decade. Excellent outcomes have been reported, however, safety concerns exist. The aim of this study was to define prerequisites for performing MIPR with the objective to guide safe implementation of MIPR into clinical practice.

METHODS

This systematic review was conducted as part of the 2019 Miami International Evidence-Based Guidelines on Minimally Invasive Pancreas Resection (IG-MIPR). PubMed, Embase and Cochrane databases were searched for literature concerning the implementation of MIPR between 1946 and November 2018. Quality assessment was according to The Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

Overall, 1150 studies were screened, of which 32 studies with 8519 patients were included in this systematic review. Training programs for minimally invasive distal pancreatectomy, laparoscopic pancreatoduodenectomy and robotic pancreatoduodenectomy have been described with acceptable outcomes during the learning curve and improved outcomes after training. Learning curve studies have revealed an association between growing experience and improving perioperative outcomes. In addition, the association between higher center volume and lower mortality and morbidity has been reported by several studies.

CONCLUSION

When embarking on MIPR, it is recommended to participate in a dedicated training program, to assure a sufficient volume, especially when implementing minimally invasive pancreatoduodenectomy, (20 procedures recommended annually), and prospectively collect and closely monitor outcomes for continuous quality assessment, this can be achieved through institutional databases and participation in national or international registries.