BACKGROUND: Postoperative mortality plays an important role in evaluating the surgical safety of esophagectomy. Although postoperative mortality after esophagectomy is partly influenced by the yearly hospital surgical case volume (hospital volume), this association remains unclear.
METHODS: Studies assessing the association between hospital volume and postoperative mortality in patients who underwent esophagectomy for esophageal cancer were searched for eligibility. Odds ratios were pooled for the highest versus lowest categories of hospital volume using a random effects model. The dose-response association between hospital volume and the risk of postoperative mortality was analyzed. The study protocol was registered with PROSPERO.
RESULTS: Fifty-six studies including 385 469 participants were included. A higher-volume hospital significantly reduced the risk of postesophagectomy mortality by 53% compared with their lower-volume counterparts (odds ratio, 0.47; 95% CI: 0.42-0.53). Similar results were found in subgroup analyses. Volume-outcome analysis suggested that postesophagectomy mortality rates remained roughly stable after the hospital volume reached a plateau of 45 esophagectomies per year.
CONCLUSIONS: Higher-volume hospitals had significantly lower postesophagectomy mortality rates in patients with esophageal cancer, with a threshold of 45 esophagectomies per year for a high-volume hospital. This remarkable negative correlation showed the benefit of a better safety in centralization of esophagectomy to a high-volume hospital.

Studies of neurosurgical pediatric patients associate treatment at low-volume hospitals and by low-volume surgeons with increased odds of adverse outcomes. Although these associations suggest that increased centralization of care could be considered, we evaluate whether confounding endogenous factors mitigate against the proposed outcome benefits.
Literature review of English language articles from 1999 to 2021. We included articles that assessed volume-outcome effects in pediatric neurosurgical patients.
Twelve papers were included from 1999 to 2021. Primary outcomes included mortality (9), length of stay (LOS) (6), complications (4), and shunt revision/failure rates (3). Volume was measured at the hospital level (8) and at the surgeon level (6). Four papers found that higher volume hospitals had lower odds of mortality. Two papers found that hospitals with higher volume had fewer complications. Two papers found that higher volume surgeons had decreased mortality (odds ratio [OR] 0.09-0.3). One paper found that high-volume surgeons had fewer complications (-2.4%; P = 0.006). After controlling for hospital factors (HF), two out of 7 analyses remained significant. Five analyses did not control for HF.
The literature consistently demonstrates a relationship between higher hospital and surgeon volume and better outcomes for pediatric neurosurgical patients. Of the 7 articles that assessed HF, only 2 analyses found that surgical volume remained associated with better outcomes. No reports assessed the degree of centralization already present. The call for centralization of pediatric care should be tempered until variables such as hospital factors, distribution of cases, and clinical thresholds can be defined and studied.

BACKGROUND: Pancreaticoduodenectomy (PD) is associated with better outcomes in high-volume hospitals. However, it is unknown whether and to what extent the improved performance of high-volume hospitals may be associated with racial and socioeconomic factors, which have been shown to impact operative and postoperative outcomes in major surgeries. This review aims to identify the differences in racial and socioeconomic characteristics of patients who underwent PD surgery in high- and low-volume hospitals.
METHODS: PubMed, Cochrane, and Web of Science were systematically searched between May 1, 2023 and May 7, 2023 without any time restriction on publication date. Studies that were conducted in the United States and had a direct comparison between high- and low-volume hospitals were included.
RESULTS: A total of 30 observational studies were included. When racial proportions were compared by hospital volume, thirteen studies reported that compared to high-volume hospitals, a higher percentage of racial minorities underwent PD in low-volume hospitals. Disparities in traveling distance, education levels, and median income at baseline between high- and low-volume hospitals were reported by four, three, and two studies, respectively.
CONCLUSIONS: A racial difference at baseline between high- and low-volume hospitals was observed. Socioeconomic factors were less frequently included in existing literature. Future studies are needed to understand the socioeconomic differences between patients receiving PD surgery in high- and low-volume hospitals.

BACKGROUND: Validity of the laparoscopic approach in pancreatic head lesion remains debatable. This study aims to compare the safety and effectiveness of laparoscopic pancreatoduodenectomy (LPD) and open pancreatoduodenectomy (OPD) and investigate the source of heterogeneity from surgeons\' and patients\' perspectives.
METHODS: We searched PubMed, Cochrane, Embase, and Web of Science for studies published before February 1, 2021. Of 6578 articles, 81 were full-text reviewed. The primary outcome was mortality. Three independent reviewers screened and extracted the data and resolved disagreements by consensus. Studies were evaluated for quality using ROB2.0 and ROBINS-I. According to different study designs, sensitivity and meta-regression analyses were conducted to explore the heterogeneity source. This meta-analyses was also conducted to explore the learning curve\'s heterogeneity. This study was registered with PROSPERO, CRD42021234579.
RESULTS: We analyzed 34 studies involving 46,729 patients (4705 LPD and 42,024 OPD). LPD was associated with lower (P = 0.025) in unmatched studies (P = 0.017). No differences in mortality existed in randomized controlled trials (P = 0.854) and matched studies (P = 0.726). Sensitivity analysis found no significant difference in mortality in elderly patients, patients with pancreatic cancer, and in high- and low-volume hospitals (all P > 0.05). In studies at the early period of LPD (<40 cases), higher mortality (P < 0.001) was found (all P < 0.05).LPD showed non-inferiority in length of stay, complications, and survival outcomes in all analyses.
CONCLUSIONS: In high-volume centers with adequate surgical experience, LPD in selected patients appears to be a valid alternative to LPD with comparable mortality, LOS, complications, and survival outcomes.

BACKGROUND: Newborns with gastroschisis need surgery to reduce intestines into the abdominal cavity and to close the abdominal wall. Due to an existing volume-outcome relationship for other high-risk, low-volume procedures, we aimed at examining the relationship between hospital or surgeon volume and outcomes for gastroschisis.
METHODS: We conducted a systematic literature search in Medline, Embase, CENTRAL, CINAHL and Biosis Previews in June 2021 and searched for additional literature. We included (cluster-) randomized controlled trials (RCTs) and prospective or retrospective cohort studies analyzing the relationship between hospital or surgeon volume and mortality, morbidity or quality of life. We assessed risk of bias of included studies using ROBINS-I and performed a systematic synthesis without meta-analysis and used GRADE for assessing the certainty of the evidence.
RESULTS: We included 12 cohort studies on hospital volume. Higher hospital volume may reduce in-hospital mortality of neonates with gastroschisis, while the evidence is very uncertain for other outcomes. Findings are based on a low certainty of the evidence for in-hospital mortality and a very low certainty of the evidence for all other analyzed outcomes, mainly due to risk of bias and imprecision. We did not identify any study on surgeon volume.
CONCLUSIONS: The evidence suggests that higher hospital volume reduces in-hospital mortality of newborns with gastroschisis. However, the magnitude of this effect seems to be heterogeneous and results should be interpreted with caution. There is no evidence on the relationship between surgeon volume and outcomes.

Pancreatic cancer remains a highly fatal disease with a 5-year overall survival of less than 10%. In seeking to improve clinical outcomes, there is ongoing debate about the weight that should be given to patient volume in centralization models. The aim of this systematic review is to examine the relationship between patient volume and clinical outcome after pancreatic resection for cancer in the contemporary literature.
The Google Scholar, PubMed, and Cochrane Library databases were systematically searched from February 2015 until June 2021 for articles reporting patient volume and outcomes after pancreatic cancer resection.
There were 46 eligible studies over a 6-year period comprising 526,344 patients. The median defined annual patient volume thresholds varied: low-volume 0 (range 0-9), medium-volume 9 (range 3-29), high-volume 19 (range 9-97), and very-high-volume 28 (range 17-60) patients. The latter 2 were associated with a significantly lower 30-day mortality (P < .001), 90-day mortality (P < .001), overall postoperative morbidity (P = .005), failure to rescue rate (P = .006), and R0 resection rate (P = .008) compared with very-low/low-volume hospitals. Centralization was associated with lower 30-day mortality in 3 out of 5 studies, while postoperative morbidity was similar in 4 out of 4 studies. Median survival was longer in patients traveling greater distance for pancreatic resection in 2 out of 3 studies. Median and 5-year survival did not differ between urban and rural settings.
The contemporary literature confirms a strong relationship between patient volume and clinical outcome for pancreatic cancer resection despite expected bias toward more complex surgery in high-volume centers. These outcomes include lower mortality, morbidity, failure-to-rescue, and positive resection margin rates.

OBJECTIVE: To investigate whether there is a correlation between institutional or surgeon case volume and outcomes in patients with ruptured abdominal aortic aneurysm (rAAA).
METHODS: The Healthcare Database Advanced Search interface developed by the National Institute of Health and Care Excellence was used to search MEDLINE, Embase, CINAHL, and CENTRAL.
METHODS: The systematic review complied with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines with the protocol registered in PROSPERO (CRD42020213121). Prognostic studies were considered comparing outcomes of patients with rAAA undergoing repair in high and low volume institutions or by high and low volume surgeons. Pooled estimates for peri-operative mortality were calculated using the odds ratio (OR) and 95% confidence intervals (CI), applying the Mantel-Haenszel method. Analysis of adjusted outcome estimates was performed with the generic inverse variance method.
RESULTS: Thirteen studies reporting a total of 120 116 patients were included. Patients treated in low volume centres had a statistically significantly higher peri-operative mortality than those treated in high volume centres (OR 1.39; 95% CI 1.22 - 1.59). Subgroup analysis showed a mortality difference in favour of high volume centres for both endovascular aneurysm repair (EVAR; OR 1.61, 95% CI 1.11 - 2.35) and open repair (OR 1.50, 95% CI 1.25 - 1.81). Adjusted analysis showed a benefit of treatment in high volume centres for open repair (OR 1.68, 95% CI 1.21 - 2.33) but not for EVAR (OR 1.42, 95% CI 0.84 - 2.41). Differences in peri-operative mortality between low and high volume surgeons were not statistically significant for either EVAR (OR 1.06, 95% CI 0.59 - 1.89) or open surgical repair (OR 1.18, 95% CI 0.87 - 1.63).
CONCLUSIONS: A high institutional volume may result in a reduction of peri-operative mortality following surgery for rAAA. This peri-operative survival advantage is more pronounced for open surgery than EVAR. Individual surgeon caseload was not found to have a significant impact on outcomes.

BACKGROUND: There is convincing evidence that birth in hospitals with high birth volumes increases the chance of healthy survival in high-risk infants. However, it is unclear whether this is true also for low risk infants. The aim of this systematic review was to analyze effects of hospital\'s birth volume on mortality, mode of delivery, readmissions, complications and subsequent developmental delays in all births or predefined low risk birth cohorts. The search strategy included EMBASE and Medline supplemented by citing and cited literature of included studies and expert panel highlighting additional literature, published between January/2000 and February/2020. We included studies which were published in English or German language reporting effects of birth volumes on mortality in term or all births in countries with neonatal mortality < 5/1000. We undertook a double-independent title-abstract- and full-text screening and extraction of study characteristics, critical appraisal and outcomes in a qualitative evidence synthesis.
RESULTS: 13 retrospective studies with mostly acceptable quality were included. Heterogeneous volume-thresholds, risk adjustments, outcomes and populations hindered a meta-analysis. Qualitatively, four of six studies reported significantly higher perinatal mortality in lower birth volume hospitals. Volume-outcome effects on neonatal mortality (n = 7), stillbirths (n = 3), maternal mortality (n = 1), caesarean sections (n = 2), maternal (n = 1) and neonatal complications (n = 1) were inconclusive.
CONCLUSIONS: Analyzed studies indicate higher rates of perinatal mortality for low risk birth in hospitals with low birth volumes. Due to heterogeneity of studies, data synthesis was complicated and a meta-analysis was not possible. Therefore international core outcome sets should be defined and implemented in perinatal registries.
UNASSIGNED: PROSPERO: CRD42018095289.

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.
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.
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.
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.

BACKGROUND: In the past, for a number of abdominal surgical interventions a correlation between treatment volume of a hospital and the patient\'s outcome was shown in national and international studies.
METHODS: Based on a systematic literature search we analyzed the absolute and risk-adjusted in-house lethality as well as the rate of complications and the failure to rescue after abdominal surgery in Germany. The hospitals were grouped in quintiles according to the volume of treatment.
RESULTS: 11 studies including more than 2 million patients were identified and surgeries for the treatment of 9 disease conditions were studied. The meta-analysis shows a significantly lower absolute and risk-adjusted in-house mortality for surgery in hospitals with high treatment volumes compared to low volume hospitals. In the context of subgroup analysis, this effect is demonstrated especially for complex surgical procedures. The failure to rescue in patients suffering from sepsis is significantly lower in high volume centers compared to low volume centers.
CONCLUSIONS: This systematic review and meta-analysis shows on more than 2 million patients that there is a volume-outcome relationship for the surgical treatment of abdominal diseases in Germany across various organ systems, which is particularly true for complex interventions.