Association between the participation of board-certified surgeons in gastroenterological surgery and operative mortality after eight gastroenterological procedures

Outcome research on esophagectomy analyzed using nationwide databases in Japan: evidences generated from real-world data

Esophagectomy for esophageal cancer is a highly invasive gastrointestinal surgical procedure. The National Clinical Database (NCD) of Japan, initiated in 2011, has compiled real-world data on esophagectomy, one of nine major gastroenterological surgeries. This review examines outcomes after esophagectomy analyzed using the Japanese big databases. Certification systems by the Japanese Society of Gastroenterological Surgery (JSGS) and the Japan Esophageal Society (JES) have shown that institutional certification has a greater impact on short-term surgical outcomes than surgeon certification. Minimally invasive esophagectomy has emerged as a viable alternative to open esophagectomy, although careful patient selection is crucial, especially for elderly patients with advanced tumors. The NCD has significantly contributed to the assessment and enhancement of surgical quality and short-term outcomes, while studies based on Comprehensive Registry of Esophageal Cancer in Japan (CRECJ) have provided data on patient characteristics, treatments, and long-term outcomes. The JES has conducted various questionnaire-based retrospective clinical reviews in collaboration with authorized institutions certified by JES. The Diagnosis Procedure Combination (DPC) database provides administrative claims data including itemized prices for surgical, pharmaceutical, laboratory, and other inpatient services. Analyzing these nationwide databases can offer precise insights into surgical quality for esophageal cancer, potentially leading to improved treatment outcomes.

Impact of a board certification system and adherence to the clinical practice guidelines for gastric cancer on risk-adjusted surgical mortality after distal and total gastrectomy in Japan: a questionnaire survey of departments registered in the National Clinical Database

PURPOSE

The relationship between board certification, clinical guideline implementation, and quality of gastric cancer surgery remains unclear.

METHODS

A web-based questionnaire survey was administered to departments registered in the National Clinical Database (NCD) of Japan between October 2014 and January 2015. Quality indicators (QIs) based on the Donabedian model were evaluated. Structural QIs (e.g., affiliations with academic societies and board certifications) and process QIs (adherence to clinical practice guidelines for gastric cancer) were assessed using risk-adjusted odds ratios (AORs) for surgical mortality. Multivariable logistic regression models with a generalized estimating equation were used.

RESULTS

A total of 835 departments performing 40,992 distal gastrectomies and 806 departments performing 19,618 total gastrectomies responded. Some certified institutions and physicians showed significant associations, with lower AORs for surgical mortality. Important process QIs included pre- and postoperative abdominal CT scanning, endoscopic resection based on progression, curative resection with D2 dissection for advanced gastric cancer, laparoscopic surgery, and HER2 testing for patients with unresectable recurrent gastric cancer.

CONCLUSIONS

Multiple structural and process QIs are associated with surgical mortality after gastrectomy in Japan. Measuring and visualizing QIs may enhance healthcare improvements.

Annual report on National Clinical Database 2020 for gastroenterological surgery in Japan

Aim

The National Clinical Database (NCD) of Japan is a nationwide data entry system for surgery, and it marked its 10th anniversary in 2020. The aim was to present the 2020 annual report of gastroenterological surgery of the NCD.

Methods

The data of the surgical procedures stipulated by the training curriculum for board-certified surgeons of the Japanese Society of Gastroenterological Surgery in the NCD from 2011 to 2020 were summarized.

Results

In total, 5 622 845 cases, including 593 088 cases in 2020, were extracted from the NCD. The total number of gastroenterological surgeries increased gradually in these 10 years, except for the year 2020 due to the COVID-19 pandemic. The annual number of surgeries of each organ, except the pancreas and liver, decreased by 0.4%-13.1% in 2020 compared to 2019. The surgical patients were consistently aging, with more than 20% of all gastroenterological surgeries in 2020 involving patients aged 80 years or older. The participation of board-certified surgeons increased for each organ (75.9%-95.7% in 2020). The rates of endoscopic surgery also increased constantly. Although the incidences of postoperative complications of each organ increased by 0.7%-7.9% in these 10 years, postoperative mortality rates decreased by 0.2%-1.5%.

Conclusions

We present here the short-term outcomes of each gastroenterological operative procedure in 2020. This review of the 10-years of NCD data of gastroenterological surgery revealed a consistent increase of the number of surgeries (except for in 2020), especially endoscopic procedures, and aging of the Japanese population. The good safety of Japanese gastroenterological surgeries was also indicated.

Impact of the hospital volume and setting on postoperative complications of surgery for gastroenterological cancers in a regional area of Western Japan

PURPOSE

A research subgroup was established by the Japanese Society of Gastroenterological Surgery to improve the health care quality in the Chushikoku area of Western Japan.

METHODS

The records of four surgical procedures were extracted from the Japanese National Clinical Database and analyzed retrospectively to establish the association between hospital characteristics, defined using a combination of hospital case-volume and patients' hospital travel distance, and the incidences of perioperative complications of ≥ Grade 3 of the Clavien-Dindo classification after gastroenterological surgery.

RESULTS

This study analyzed 11,515 cases of distal gastrectomy for gastric cancer, 4,705 cases of total gastrectomy for gastric cancer, 4,996 cases of right hemicolectomy for colon cancer, and 5,243 cases of lower anterior resection for rectal cancer, with composite outcome incidences of 5.6%, 10.2%, 5.5%, and 10.7%, respectively. After adjusting for patient characteristics and surgical procedures, no association was identified between the hospital category and surgical outcomes.

CONCLUSION

The findings of our study of the Chushikoku region did not provide positive support for the consolidation and centralization of hospitals, based solely on hospital case volume. Our grouping was unique in that we included patient travel distance in the analysis, but further investigations from other perspectives are needed.

Impact of board certification system and adherence to the clinical practice guidelines for liver cancer on post-hepatectomy risk-adjusted mortality rate in Japan: A questionnaire survey of departments registered with the National Clinical Database

Background

It is unclear to what extent a board certification system and implementation of clinical guidelines improves the quality of hepatectomy.

Methods

A web‐based questionnaire survey was administered to departments registered with the National Clinical Database (NCD) in Japan between 1 October 2014 and 31 January 2015. Quality indicators (QIs), including affiliations with academic societies, numbers of board‐certified doctors affiliated with each institute, and adherence to clinical practice guidelines for hepatocellular carcinoma, were evaluated by calculating risk‐adjusted odds ratios (AORs) for 90‐day postoperative mortality of patients who had undergone hepatectomy in 2013 and 2014.

Results

Of 1255 departments that had registered at least one hepatectomy in NCD, 592 departments, performing 8601 hepatectomies in total, responded to the questionnaire. AORs were significantly lower in departments that were certified as training hospitals by the Japanese Society of Gastroenterological Society, Japanese Society of Hepato‐Biliary‐Pancreatic Surgery (JSHBPS), and Japan Society of Hepatology than in non‐certified departments. Affiliation of three or more JSHBPS‐certified experts or instructors with an institution also contributed to low AORs. None of the QIs regarding implementation of guidelines significantly impacted on the AOR.

Conclusions

Quality indicator measurements may improve quality of post‐hepatectomy outcomes in Japan.

Profiles of institutional departments affect operative outcomes of eight gastroenterological procedures

AIM

We evaluated the association of profiles of institutional departments with operative outcomes of eight major gastroenterological procedures.

METHODS

We administered a 15-item online survey to 2634 institutional departments in 2016 to investigate the association of questionnaire responses with operative mortality for the procedures. The proportions of conditions met were listed according to institutional volume and classified according to annual operative cases in 1464 departments. Group A included departments with annual performance of <40 cases of the eight procedures, B 40-79 cases, C 80-199 cases, D 200-499 cases, and E ≥ 500 cases. We evaluated the number of conditions met for 10 of 15 items that could be improved by efforts of institutional departments, to assess whether the profiles of institutional departments had impacts on operative mortality. We built a multivariable logistic regression model for operative mortality with facilities categorized based on the number of conditions met and procedure-specific predicted mortality as explanatory variables using generalized estimating equation to account for facility-level clustering. We also examined how operative outcomes differed between facilities meeting nine or more conditions and those that did not.

RESULTS

We recognized meeting nine out of the 10 conditions as being a good indicator for having appropriate structural and process measures for gastroenterological surgery. The facilities meeting nine or more of the conditions had better operative mortality for all eight procedures.

CONCLUSIONS

Our findings reveal that the profiles of institutional departments can reflect the outcomes of gastroenterological surgery in Japan.

Estimates of the effects of centralization policy for surgery in Japan: does centralization affect the quality of healthcare for esophagectomies?

PURPOSE

This study compared the quality of healthcare before and after implementation of a policy restructuring the healthcare delivery system and estimated the impact of centralization.

METHODS

We used the National Clinical Database to study patients undergoing esophagectomies from 2011 to 2016. We compared the effect of centralization based on the patient background, surgical mortality, and year of surgery. Difference-in-difference methods based on the generalized estimating equation logistic regression model were used for before-and-after comparisons after adjusting for patient-level expected surgical mortality.

RESULTS

In total, 34,640 cases were identified. More cases with risk factors were noted in ultra-low-volume hospitals, where 38.4% of cases in underpopulated areas were treated, than in higher volume facilities, and the operative mortality, readmission within 30 days and length of stay were worse among patients treated in these hospitals. In centralized prefectures, the number of cases per hospital increased over time (7.2 in 2011 to 9.5 in 2016) while the crude operative mortality tended to decrease (3.4% in 2011 to 1.8% in 2016). The difference-in-difference estimator was 0.856 (95% confidence interval: 0.639-1.147, p = 0.298).

CONCLUSION

The centralization of ultra-low-volume hospitals did not lead to a deterioration in the quality of care but rather an improving trend.

Association of surgeon and hospital volume with postoperative mortality after total gastrectomy for gastric cancer: data from 71,307 Japanese patients collected from a nationwide web-based data entry system

BACKGROUND

Despite interest in surgeon and hospital volume effects on total gastrectomy (TG), clinical significance has not been confirmed in a large-scale population. This study aimed at clarifying the association of surgeon and hospital volume on postoperative mortality after TG for gastric cancer among Japanese patients in National Clinical Database (NCD).

METHODS

Between 2011 and 2015, we retrospectively extracted data on TG for gastric cancer from the NCD. The primary outcome was operative mortality. We divided surgeon volume as the number of TGs performed by a patient's surgeon in the previous year: S1 (0-2 cases), S2 (3-9), S3 (10-25), S4 (26-79) and hospital volume by the number of TGs performed in the previous year: H1 (0-11 cases), H2 (12-26), H3 (27-146). We calculated the 95% confidence interval (CI) for the mortality rate based on odds ratios (OR) estimated from a hierarchical logistic regression model.

RESULTS

We analyzed 71,307 patients at 2051 institutions. Low-volume surgeons and hospitals had significantly older and poorer-risk patients with various comorbidities. The operative mortality rate decreased with surgeon volume, 2.5% in S1 and 0.6% in S4. The operative mortality was 3.1% in H1, 1.7% in H2, and 1.2% in H3. After risk adjustment for surgeon, hospital volume and patient characteristics, hospital volume was significantly associated with operative morality (H3: OR = 0.53, 95% CI 0.43-0.63).

CONCLUSIONS

We demonstrate hospital volume has an impact on postoperative mortality after TG in a nationwide population study. These findings suggest centralization may improve outcomes after TG.

Certified thoracic surgeons in Japan: a national database survey on risk-adjusted mortality associated with lung resection

PURPOSE

We investigated the association between the number of certified general thoracic surgeons (GTSs) and the mortality after lung cancer surgery, based on the data from the National Clinical Database (NCD).

METHODS

We analyzed the characteristics and operative and postoperative data of 120,946 patients who underwent lung cancer surgery in one of the 905 hospitals in Japan. The number of GTSs in each hospital was categorized as 0, 1-2, or 3 or more. Multivariable analysis was applied to adjust the patients' preoperative risk factors, as identified in a previous study. We calculated 95% confidence intervals (CI) for the mortality rate based on the odds ratios (ORs).

RESULTS

The patients' characteristics were distributed almost uniformly regardless of the number of GTSs. Crude mortality according to the number of GTSs of 0, 1-2, or 3 or more was 0.9%, 0.8%, and 0.7%, respectively (p = 0.03). However, after adjustment, the ORs for 1-2 and 3 or more GTSs (reference: 0) were 0.86 (p = 0.23, 95% CI: 0.67-1.10) and 0.84 (p = 0.18, 95% CI: 0.64-1.09), respectively. The number of GTSs did not have a significant association with mortality. Similar results were observed for patients in the lobectomy cohort.

CONCLUSION

Low surgical mortality was consistent, regardless of the number of GTSs in each hospital.

Preoperative risk factors for postoperative intra-abdominal infectious complication after gastrectomy for gastric cancer using a Japanese web-based nationwide database

BACKGROUND

Postoperative intra-abdominal infectious complication (PIIC) after gastrectomy for gastric cancer worsens in-hospital death or long-term survival. However, the methodology for PIIC preoperative risk assessment remains unestablished. We aimed to develop a preoperative risk model for postgastrectomy PIIC.

METHODS

We collected 183,936 patients' data on distal or total gastrectomy performed in 2013-2016 for gastric cancer from the Japanese National Clinical Database and divided into development (2013-2015; n = 140,558) and validation (2016; n = 43,378) cohort. The primary outcome was the incidence of PIIC. The risk model for PIIC was developed using 18 preoperative factors: age, sex, body mass index, activities of daily living, 12 comorbidity types, gastric cancer stage, and surgical procedure in the development cohort. Secondarily, we developed another model based on the new scoring system for clinical use using selected factors.

RESULTS

The overall incidence of PIIC was 4.7%, including 2.6%, 1.7%, and 1.3% in anastomotic leakage, pancreatic fistula, and intra-abdominal abscess, respectively. Among the 18 preoperative factors, male [odds ratio, (OR) 1.92], obesity (OR, 1.52-1.96), peripheral vascular disease (OR, 1.55), steroid use (OR, 1.83), and total gastrectomy (OR, 1.89) strongly correlated with PIIC incidence. The entire model using the 18 factors had good discrimination and calibration in the validation cohort. We selected eight relevant factors to create a simple scoring system, using which we categorized the patients into three risk groups, which showed good calibration.

CONCLUSION

Using nationwide clinical practice data, we created a preoperative risk model for postgastrectomy PIIC for gastric cancer.

Development of gastroenterological surgery over the last decade in Japan: analysis of the National Clinical Database

The National Clinical Database (NCD) of Japan was established in 2010 with the board certification system. A joint committee of 16 gastroenterological surgery database-affiliated organizations has been nurturing this nationwide database and utilizing its data for various analyses. Stepwise board certification systems have been validated by the NCD and are used to improve the surgical outcomes of patients. The use of risk calculators based on risk models can be particularly helpful for establishing appropriate and less invasive surgical treatments for individual patients. Data obtained from the NCD reflect current developments in the surgical approaches used in hospitals, which have progressed from open surgery to endoscopic and robot-assisted procedures. An investigation of the data acquired by the NCD could answer some relevant clinical questions and lead to better surgical management of patients. Furthermore, excellent surgical outcomes can be achieved through international comparisons of the national databases worldwide. This review examines what we have learned from the NCD of gastroenterological surgery and discusses what future developments we can expect.

Does anastomotic leakage after rectal cancer resection worsen long-term oncologic outcome?

PURPOSE

The influence of anastomotic leakage on long-term survival in patients with rectal cancer is debatable. The aim of this study was to evaluate relationships between anastomotic leakage and long-term survival.

METHODS

In this multicenter retrospective cohort study, 395 consecutive stage I to III rectal cancer patients underwent anterior resection between 2007 and 2012. Five-year overall survival, 5-year disease-free survival, and 5-year local recurrence-free survival were compared between patients with leakage (Leakage (+)) and patients without leakage (Leakage (-)).

RESULTS

Of 395 patients, 50 (12.7%) had anastomotic leakage. Of these 50, 34 (68.0%) required urgent surgery and 16 (32.0%) could be managed by watchful waiting or with percutaneous drainage. The median follow-up period was 62.6 months. Five-year overall survival did not differ between the two groups (Leakage (+) 93.8% vs. Leakage (-) 89.0%, P = 0.121). Five-year disease-free survival also did not differ between the two groups (81.6% vs. 80.3%, P = 0.731), and neither did 5-year local recurrence-free survival (91.9% vs. 86.1%, P = 0.206). In a multivariable Cox regression model, BMI > 25, preoperative CA19-9 > 37, pathological T stage, pathological N stage, and circumferential resection margin (CRM) positive were independent predictors of disease-free survival. Moreover, pathological T stage, pathological N stage, and CRM positive were the only independent predictors of overall survival and local recurrence-free survival. Anastomotic leakage was not a risk factor for overall survival, disease-free survival, or local recurrence-free survival.

CONCLUSION

Anastomotic leakage is not associated with a significant decrease in long-term survival in rectal cancer patients.

Impact of a board certification system and implementation of clinical practice guidelines for pancreatic cancer on mortality of pancreaticoduodenectomy

Purposes

The aim of this study was to clarify the impact of a board certification system and the implementation of clinical practice guidelines for pancreatic cancer (PC) on the mortality of pancreaticoduodenectomy in Japan.

Methods

By a web questionnaire survey via the National Clinical Database (NCD) for departments participating in the NCD, quality indicators (QIs) related to the treatment for PC, namely the board certification systems of various societies and the adherence to clinical practice guidelines for PC, were investigated between October 2014 and January 2015. A multivariable logistic regression analysis was performed to evaluate the relationship between the QIs and mortality of pancreaticoduodenectomy.

Results

Of 1415 departments that registered at least 1 pancreaticoduodenectomy between 2013 and 2014 in NCD, 631 departments (44.6%), which performed pancreaticoduodenectomy for a total of 11,684 cases, answered the questionnaire. The mortality of pancreaticoduodenectomy was positively affected by the board certification systems of the Japanese Society of Gastroenterological Surgery, Japanese Society of Hepato-Biliary-Pancreatic Surgery, Japanese Society of Gastroenterology, and Japanese Society of Medical Oncology as well as by institutions that used magnetic resonance imaging of ≥ 3 T for the diagnosis of PC in principle.

Conclusions

The measurement of the appropriate QIs is suggested to help improve the mortality in pancreaticoduodenectomy. Masamichi Mizuma and Hiroyuki Yamamoto equally contributed

Impact of adherence to board-certified surgeon systems and clinical practice guidelines on colon cancer surgical outcomes in Japan: A questionnaire survey of the National Clinical Database

AIM

To investigate the effectiveness of the institutional medical structure and of the implemented clinical practice guidelines for improving colon cancer surgical outcomes.

METHODS

We conducted a web-based questionnaire survey among departments registered at the National Clinical Database in Japan from October 2014 to January 2015 to assess the association between quality indicators (QIs), including structure and process indicators (clinical practice guideline adherence), and the risk-adjusted odds ratio for operative mortality (AOR) after right hemicolectomy for colorectal cancer during the study period.

RESULTS

Among the 2064 departments registering at least one colorectal surgery during the study period, we obtained responses from 814 departments (39.4%). Our analysis on data from 22 816 patients with right hemicolectomy demonstrated that three structural QIs (certification of training hospitals by the Japanese Society of Gastroenterological Surgery and the presences of board-certified gastroenterological and colorectal surgeons) were associated with significantly lower AOR (P < .001, P = .02, and P = .05, respectively). The "performed at the doctor's discretion" answer was associated with poorer short-term outcomes in six process QIs than other answers.

CONCLUSION

The board certification system for gastroenterological and colorectal surgeons and the adherence to the clinical guidelines improve the operative mortality after right hemicolectomy. It is desired to clarify the most suitable QIs to reduce the operative mortality after colorectal surgery.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2018

The National Clinical Database (NCD) of Japan grew rapidly, harvesting over 11 million cases of data between 2011 and 2018 from more than 5000 facilities. This is the Report of the NCD based upon gastrointestinal surgery information in 4 420 175 cases from 2011 to 2018. More than 70% of all gastrointestinal surgeries were performed at certified institutions, and the percentage of surgeries performed at certified institutions was particularly high for the esophagus (93.8% in 2018), liver (89.4%), pancreas (91.3%), and spleen (86.9%). Also, more than 70% of the surgeries were performed with the participation of the board-certified surgeon. As the patients have been getting older, the morbidities have been increasing. However, the mortalities have been kept at a low level. The rates of endoscopic surgery have been increasing year by year, especially high in low anterior resection (67.0%) and esophagectomy (61.0%). Nationwide, this database is surely expecting to ensure the quality of board certification system and surgical outcomes in gastroenterological surgery.

Risk model for severe postoperative complications after total pancreatectomy based on a nationwide clinical database

BACKGROUND

Total pancreatectomy is required to completely clear tumours that are locally advanced or located in the centre of the pancreas. However, reports describing clinical outcomes after total pancreatectomy are rare. The aim of this retrospective observational study was to assess clinical outcomes following total pancreatectomy using a nationwide registry and to create a risk model for severe postoperative complications.

METHODS

Patients who underwent total pancreatectomy from 2013 to 2017, and who were recorded in the Japan Society of Gastroenterological Surgery and Japanese Society of Hepato-Biliary-Pancreatic Surgery database, were included. Severe complications at 30 days were defined as those with a Clavien-Dindo grade III needing reoperation, or grade IV-V. Occurrence of severe complications was modelled using data from patients treated from 2013 to 2016, and the accuracy of the model tested among patients from 2017 using c-statistics and a calibration plot.

RESULTS

A total of 2167 patients undergoing total pancreatectomy were included. Postoperative 30-day and in-hospital mortality rates were 1·0 per cent (22 of 2167 patients) and 2·7 per cent (58 of 167) respectively, and severe complications developed in 6·0 per cent (131 of 2167). Factors showing a strong positive association with outcome in this risk model were the ASA performance status grade and combined arterial resection. In the test cohort, the c-statistic of the model was 0·70 (95 per cent c.i. 0·59 to 0·81).

CONCLUSION

The risk model may be used to predict severe complications after total pancreatectomy.

Surgical outcomes of gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2017

BACKGROUND

The Japanese National Clinical Database (NCD) is a large-scale, nationwide, web-based data entry system that is linked to the surgical board certification system and covers almost all surgical cases carried out in Japan.

AIM

To evaluate outcomes according to the gastroenterological section of the NCD.

METHODS

The 115 surgical procedures stipulated by the "Training Curriculum for Board-Certified Surgeons in Gastroenterology" were registered from 2011 to 2017. The number of surgeries, preoperative comorbidities, and short-term outcomes were compared between registration periods.

RESULTS

In total, 3 818 414 cases have been registered. More than 70% of all surgeries were carried out at certified institutions. The annual number of cases has been increasing year after year, and the aged population has also been increasing. Although the rates of preoperative comorbidities and postoperative complications have been increasing, the postoperative mortality rate has remained relatively low; in 2017, the 30-day mortality rate was 1.0% among those who underwent esophagectomy, 0.7% among those who underwent distal gastrectomy, 1.1% among those who underwent total gastrectomy, 1.3% among those who underwent right hemicolectomy, 0.5% among those who underwent low anterior resection, 1.3% among those who underwent hepatectomy, and 1.3% among those who underwent pancreaticoduodenectomy. The annual rate of endoscopic surgery dramatically increased over 7 years between 2011 and 2017, especially for low anterior resection (29.5%-62.6%) and esophagectomy (31.0%-56.1%).

CONCLUSION

This database is expected to ensure the quality of the board-certification system and surgical outcomes in gastroenterological surgery.

Significance of the board-certified surgeon systems and clinical practice guideline adherence to surgical treatment of esophageal cancer in Japan: a questionnaire survey of departments registered in the National Clinical Database

BACKGROUND

It remains unknown how much institutional medical structure and process of implementation of clinical practice guidelines for esophageal cancers can improve quality of surgical outcome in Japan.

METHODS

A web-based questionnaire survey was performed for departments registered in the National Clinical Database in Japan from October 2014 to January 2015. Quality indicators (QIs) including structure and process indicators (clinical practice guideline adherence) were evaluated on the risk-adjusted odds ratio for operative mortality (AOR) of the patients using registered cases in the database who underwent esophagectomy and reconstruction in 2013 and 2014.

RESULTS

Among 916 departments which registered at least one esophagectomy case during the study period, 454 departments (49.6%) responded to the questionnaire. Analyses of 6661 cases revealed that two structure QIs (certification of training hospitals by Japan Esophageal Society and presence of board-certified esophageal surgeons) were associated with significantly lower AOR (p < 0.001 and p = 0.005, respectively). One highly recommended process QI regarding preoperative chemotherapy had strong tendency to associate with lower AOR (p = 0.053). In two process QIs, the answer "performed at the doctor's discretion" showed a significant negative impact on prognosis, suggesting importance of institutional uniformity.

CONCLUSIONS

The medical institutional structure of board-certified training sites for esophageal surgeons and of participation of board-certified esophageal surgeons improves surgical outcome in Japan. Establishment of appropriate QIs and their uniform implementation would be crucial for future quality improvement of medical care in esophagectomy.

Surgical outcomes in gastroenterological surgery in Japan: Report of National Clinical database 2011-2016

The National Clinical Database (NCD) of Japan started its registration in 2011 and over 9 000 000 cases from more than 5000 facilities were registered over a 6‐year period. This is the report of NCD based upon gastrointestinal surgery information in excess of 3 200 000 cases from 2011 to 2016 adding data of complications. About 70% of all gastrointestinal surgeries were carried out at certified institutions, and the percentage of surgeries done at certified institutions was particularly high for the esophagus (92.4% in 2016), liver (88.4%), pancreas (89.8%), and spleen (86.8%). The percentage of anesthesiologist participation was more than 90% for almost all organs, except 85.7% for the rectum and anus. Approximately, more than two‐thirds of the surgeries were carried out with the participation of a board‐certified surgeon. Although patients have been getting older, mortalities have not been increasing. There were differences in the incidence of complications according to organ site and procedure. Remarkably, mortality rates of low anterior resection were very low, and those of hepatectomy and acute diffuse peritonitis surgery have been gradually decreasing. Although the complication rates were gradually increasing for esophagectomy or pancreaticoduodenectomy, the mortality rates for these procedures were decreasing. Nationwide, this database is expected to ensure the quality of the board‐certification system and surgical outcomes in gastroenterological surgery.