National Clinical Database feedback implementation for quality improvement of cancer treatment in Japan: from good to great through transparency

Short-term outcomes of robot-assisted versus conventional minimally invasive esophagectomy: A propensity score-matched study via a nationwide database

BACKGROUND

The advantages of robot-assisted minimally invasive esophagectomy (RA-MIE) over conventional minimally invasive esophagectomy (C-MIE) are unknown. This nationwide large-scale study aimed to compare surgical outcomes between RA-MIE and C-MIE using rigorous propensity score methods, including detailed covariates and relevant outcomes.

METHODS

This Japanese nationwide retrospective cohort study included RA-MIE or C-MIE for esophageal malignant tumors performed between October 2018 and December 2019 and registered in the Japanese National Clinical Database. The primary outcome measure was postoperative complications classified as Clavien-Dindo Grade IIIa or higher. Propensity score matching was performed to create a balanced covariate distribution between the two groups.

RESULTS

After propensity score matching, 1092 patients were selected. The RA-MIE group had a significantly longer operation time and greater blood loss than the C-MIE group (565 vs. 477 min and 120 vs. 90 mL). Furthermore, the R0 resection rate was lower in the RA-MIE group than in the C-MIE group (95.1% vs. 97.8%). The RA-MIE and C-MIE groups had no differences regarding overall complications ≥ Grade IIIa (22.0% vs. 20.3%, p = 0.52), 30-day mortality rates (0.4% vs. 0.5%), and operative mortality rates (0.7% vs. 0.7%). Deep SSI was less frequent (2.7% vs. 6.0%) and pulmonary embolism was more frequent (2.4% vs. 0.5%) in the RA-MIE group than in the C-MIE group.

CONCLUSIONS

In the initial phase of implementation, RA-MIE and C-MIE demonstrated comparable morbidity rates when performed by skilled board-certified endoscopic surgeons.

Annual report on National Clinical Database 2021 for gastroenterological surgery in Japan

Aim

The Japanese National Clinical Database, which covers more than 95% of the surgeries performed in Japan, is the largest nationwide database. This is the 2021 annual report of the Gastroenterological Section of the National Clinical Database, which aims to present the short-term outcomes of cases registered in 2021 and discuss significant changes and insights into gastroenterological surgeries observed over the decade.

Methods

We reviewed the data of patients registered in the National Clinical Database between 2012 and 2021.

Results

In total, 5 788 093 cases, including 597 780 cases in 2021, were extracted from the National Clinical Database. The number of surgeries resumed its original trend after a uniform decrease due to the coronavirus disease 2019 pandemic. The patient population continues to age, and the proportion of female patients is steadily increasing. The trend of surgeries being conducted in certified institutions with the involvement of board-certified surgeons is consistently rising. Moreover, the increasing trend of endoscopic surgery rate is still maintained. Although operative mortality is declining, the trend of increasing postoperative complications continues. Surgery on the esophagus, liver, and pancreas has shown substantial improvements in operative mortality, with a high participation rate of board-certified surgeons. Surgical procedures with a high incidence of emergency surgeries are characterized by low participation rates of board-certified surgeons, increased morbidity rates, and worse mortality outcomes.

Conclusion

This overview of surgical patients in Japan, obtained using data extracted from the National Clinical Database, may serve as a critical cornerstone for the future development of gastroenterological surgery.

Annual record on the number of general urological surgeries registered in the National Clinical Database system between April 2018 and December 2021 in Japan

BACKGROUND

The Japanese National Clinical Database (NCD) is a large-scale, nationwide, web-based data entry system that covers the majority of surgical cases performed in Japan. An NCD specializing in urological surgery was launched based on the NCD system in 2018.

METHODS

All urological surgeries performed at more than 1000 institutions were registered from 2018. We herein report the number of surgeries conducted as stipulated in the "Certified Urology Surgeon Training Curriculum" between April 2018 and December 2021.

RESULTS

A total of 1 377 677 cases were registered from 1185 facilities nationwide under the initiative of the Japanese Urological Association. We examined the number of procedures performed every year for each of the 10 categories.

CONCLUSIONS

The NCD system sustainably provides important information relating to the preoperative status, operational outcome, and best practice for urological surgery in Japan.

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 treatment guidelines and pivotal clinical trial results on a surgeon's decision regarding treatment for gastric cancer: a retrospective cohort study using the National Clinical Database

PURPOSES

The present study evaluated the impact of clinical guidelines for gastric cancer surgery on surgeons' choice of procedure in real-world practice. We focused on the 2014 guideline revision recommending laparoscopic surgery and the evidence concerning splenectomy for prophylactic lymphadenectomy reported in 2015 using the National Clinical Database, which is the most comprehensive database in Japan.

METHODS

We investigated the monthly percentages of laparoscopic distal gastrectomies performed for stage I gastric cancer (LDG%) and splenectomies performed during total gastrectomy for advanced cancer (TGS%) between 2014 and 2017. We evaluated the descriptive statistics of the time-series changes in the LDG%, TGS%, and annual trends of outcomes.

RESULTS

In total, 124,787 patients were enrolled. The mean LDG% and TGS% were 69.8% and 9.2%, respectively. The LDG% and TGS% were 66.4% and 16.7%, respectively, in January 2014 and 73.1% and 5.9%, respectively, in December 2017. LDG% consistently increased, and TGS% showed a consistent downward trend throughout the observation period. There was no significant change in this trend after the publication of the guideline recommendations or clinical trial results.

CONCLUSION

No significant changes in surgical procedures were observed after publication of the guidelines or results of clinical trials.

Short-term outcomes after liver resection with vascular reconstruction: Results from a study with the National Clinical Database of Japan

BACKGROUND

Although curative resection with vascular reconstruction improves the prognosis of blood-invading locally advanced hepatobiliary tumors, the mortality and morbidity of the procedure remains unclear. This study aimed to clarify the risk factors associated with mortality and morbidity in patients undergoing liver resection with vascular reconstruction.

METHODS

This retrospective observational study included 1215 patients undergoing hepatectomy of more than one section with vascular reconstruction, except for left lateral sectionectomy registered in the National Clinical Database (NCD) between 2015 and 2019. The rates of surgical mortality and relevant clinical factors were evaluated.

RESULTS

Among the four types of vascular reconstruction, portal venous reconstruction was frequently performed in 724 patients (59.6% of the enrolled patients). Surgical mortality was 8.1%. Patients with hepatic artery reconstruction had the highest surgical mortality rate of 15.8%. In other types of reconstruction, surgical mortality was 9.1% in the portal vein, 5.2% in inferior vena cava, and 4.9% in hepatic vein. Factors significantly associated with surgical mortality include age, sex (male), preoperative comorbidity (American Society of Anesthesiologists grade >3, respiratory distress, diabetes, preoperative pneumonia, weight loss, and obstructive jaundice), poorer liver functional reserve (indocyanine green retention rate at 15 min and prothrombin time/international normalized ratio >1.1) and accompanying biliary reconstruction.

CONCLUSIONS

The NCD revealed the detailed status of liver resection combined with vascular reconstruction in Japan. Based on the results of this analysis, understanding the factors that influence the outcome and postoperative course of each procedure will provide patients with accurate information and opportunities to improve future 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.

Laparoscopic gastrectomy for remnant gastric cancer: A single-center retrospective study

BACKGROUND

Laparoscopic gastrectomy (LG) for remnant gastric cancer (RGC) remains controversial because of its rarity and heterogeneity of clinical characteristics. Based on our experience, we posited that our established methodology in LG could be applied to the laparoscopic procedure for RGC surgery and introduced LG for RGC at our institution in 2004.

METHODS

This study enrolled 46 patients who underwent LG for RGC between January 2004 and December 2017. Data were obtained through a review of our prospectively maintained database. Laparoscopic total gastrectomy (LTG) was the standard surgical procedure for RGC. Laparoscopic subtotal gastrectomy (LsTG) was performed as an alternative procedure for patients with RGC located near the anastomotic site after primary gastrectomy. The technical and oncological feasibility and safety of LG for RGC were evaluated.

RESULTS

LTG for RGC was performed on 36 patients. LsTG for RGC was performed on 10 patients. All patients completed LG procedure and succeeded R0 resection. Complications of Clavien-Dindo classification grade ≥ IIIa occurred in 4 (8.7%) patients. The retrospective video reviews showed that the time for adhesiotomy around the suprapancreatic area and the lesser curvature of the remnant stomach was significantly shorter in the primary-benign group than in the primary-malignant group. With the median follow-up period of 40 months, the 3-year recurrence-free survival and 3-year overall survival rates were 72.3% and 80.2%, respectively.

CONCLUSION

LG for RGC represents a safe and feasible surgical option with favorable short-term and long-term outcomes in patients with RGC.

Safety of laparoscopic liver resection for high-risk patients

BACKGROUND/PURPOSE

To investigate the safety of laparoscopic liver resections (LLRs) for high-risk patients (HRs) with preoperative comorbidities affecting the heart, lungs, kidneys, glucose tolerance, and central nervous system.

METHODS

This retrospective study included 585 patients who had undergone total hepatectomies from 2006 to 2020. Among them, 239 patients underwent LLRs, and 349 underwent open liver resections (OLRs). The safety and validity of LLRs were analyzed by comparing outcomes and preoperative records between HRs and nonhigh-risk patients (nHRs). HRs were defined as patients with any type of chronic heart disease rated New York Heart Association II or higher, chronic obstructive pulmonary disease rated stage III or higher, chronic kidney disease rated stage III or higher, insulin-dependent diabetes mellitus, or cerebrovascular disease with neurological sequelae.

RESULTS

A total of 117 LLRs (49.0%) were performed in HRs, and there were more patients with ASA class III or higher than nHRs. Complications of Clavien-Dindo classification grade 3b or higher were not observed in HRs and in only one nHR. Furthermore, no postoperative exacerbations of the five HRs factors were observed in either group.

CONCLUSIONS

Rigorous assessment of surgical indications and perioperative management can promote safe LLRs, even in HRs with comorbidities.

Morbidity after left trisectionectomy for hepato-biliary malignancies: An analysis of the National Clinical Database of Japan

BACKGROUND

The aim of this study was to analyze the nationwide surgical outcome of a left trisectionectomy (LT) and to identify the perioperative risk factors associated with its morbidity.

METHODS

Cases of LT for hepato-biliary malignancies registered at the Japanese National Clinical Database between 2013 and 2019 were retrospectively reviewed. Statistical analyses were performed to identify the perioperative risk factors associated with a morbidity of Clavien-Dindo classification (CD) ≥III.

RESULTS

Left trisectionectomy was performed on 473 and 238 cases of biliary and nonbiliary cancers, respectively. Morbidity of CD ≥III and V occurred in 45% and 5% of cases with biliary cancer, respectively, compared with 26% and 2% of cases with nonbiliary cancer, respectively. In multivariable analyses, biliary cancer was significantly associated with a morbidity of CD ≥III (odds ratio, 1.87; p = .018). In subgroup analyses for biliary cancer, classification of American Society of Anesthesiologists physical status (ASA-PS) 2, portal vein resection (PVR), and intraoperative blood loss ≥30 mL/kg were significantly associated with a morbidity of CD ≥III.

CONCLUSIONS

Biliary cancer induces severe morbidity after LT. The ASA-PS classification, PVR, and intraoperative blood loss indicate severe morbidity after LT for biliary cancer.

Risk factors for postoperative anastomotic leakage after repair of esophageal atresia: a retrospective nationwide database study

PURPOSE

Postoperative anastomotic leakage is the most frequent short-term complication of esophageal atresia repair in neonates. We conducted this study using a nationwide surgical database in Japan to identify the risk factors for anastomotic leakage in neonates undergoing esophageal atresia repair.

METHODS

Neonates diagnosed with esophageal atresia between 2015 and 2019 were identified in the National Clinical Database. Postoperative anastomotic leakage was compared among patients to identify the potential risk factors, using univariate analysis. Multivariable logistic regression analysis included sex, gestational age, thoracoscopic repair, staged repair, and procedure time as independent variables.

RESULTS

We identified 667 patients, with an overall leakage incidence of 7.8% (n = 52). Anastomotic leakage was more likely in patients who underwent staged repairs than in those who did not (21.2% vs. 5.2%, respectively) and in patients with a procedure time > 3.5 h than in those with a procedure time < 3.5 h (12.6% vs. 3.0%, respectively; p < 0.001). Multivariable logistic regression analysis identified staged repair (odds ratio [OR] 4.89, 95% confidence interval [CI] 2.22-10.16, p < 0.001) and a longer procedure time (OR 4.65, 95% CI 2.38-9.95, p < 0.001) as risk factors associated with postoperative leakage.

CONCLUSION

Staged procedures and long operative times are associated with postoperative anastomotic leakage, suggesting that leakage is more likely after complex esophageal atresia repair and that such patients require refined treatment strategies.

Comparison of short-term outcomes between robot-assisted and laparoscopic rectal surgery for rectal cancer: A propensity score-matched analysis using the Japanese Nationwide diagnosis procedure combination database

Background

The use of robot-assisted surgery for rectal cancer is increasing, but its short-term results remain unclear. We compared the short-term outcomes of robot-assisted and laparoscopic surgery for rectal cancer using a nationwide inpatient database.

Methods

We analyzed patients registered in the Japanese Diagnosis Procedure Combination database who underwent robot-assisted or laparoscopic surgery for rectal cancer from April 2018 to March 2020. Postoperative complication rates, anesthesia time, length of hospital stay, and cost were compared using propensity score matching for low anterior resection (LAR), high anterior resection (HAR), and abdominoperineal resection (APR).

Results

Among 38 090 rectal cancer cases, 1992 LAR, 357 HAR, and 310 APR pairs were generated by propensity score matching and analyzed. Anesthesia time was longer for robot-assisted surgery compared with laparoscopic surgery (LAR: 388.6 vs. 452.8 min, p < 0.001; HAR: 300.9 vs. 393.5 min, p < 0.001; APR: 4478.5 vs. 533.5 min, p < 0.001). Robot-assisted surgery was associated with significantly shorter hospital stay for LAR (22.3 vs. 20.0 days, p < 0.001) and APR (29.2 vs. 25.9 days, p = 0.029). Total costs for LAR were significantly lower for robot-assisted surgery (2031511.6 vs. 1955216.6 JPY, p < 0.001). The complication rates for robot-assisted surgery tended to be fewer than laparoscopic surgery for all procedures, but the differences were not significant.

Conclusions

Although the anesthesia time was longer for robot-assisted surgery, the procedure resulted in shorter hospital stay for LAR and APR, and lower costs for LAR compared with laparoscopic surgery. Robot-assisted surgery can thus help to reduce costs and can be performed safely.

Studies of Health Insurance Claims Data in Japan: A Scoping Review

Background

Health insurance claims data are used in various research fields; however, an overview on how they are used in healthcare research is scarce in Japan. Therefore, we conducted a scoping review to systematically map the relevant studies using Japanese claims data.

Methods

MEDLINE, EMBASE, and Ichushi-Web were searched up to April 2021 for studies using Japanese healthcare claims data. We abstracted the data on study characteristics and summarized target diseases and research themes by the types of claims database. Moreover, we described the results of studies that aimed to compare health insurance claims data with other data sources narratively.

Results

A total of 1,493 studies were included. Overall, the most common disease classifications were "Diseases of the circulatory system" (18.8%, n = 281), "Endocrine, nutritional, and metabolic diseases" (11.5%, n = 171; mostly diabetes), and "Neoplasms" (10.9%, n = 162), and the most common research themes were "medical treatment status" (30.0%, n = 448), "intervention effect" (29.9%, n = 447), and "clinical epidemiology, course of diseases" (27.9%, n = 417). Frequent diseases and themes varied by type of claims databases. A total of 19 studies aimed to assess the validity of the claims-based definition, and 21 aimed to compare the results of claims data with other data sources. Most studies that assessed the validity of claims data compared to medical records were hospital-based, with a small number of institutions.

Conclusions

Claims data are used in various research areas and will increasingly provide important evidence for healthcare policy in Japan. It is important to use previous claims database studies and share information on methodology among researchers, including validation studies, while informing policymakers about the applicability of claims data for healthcare planning and management.

The clinical impact of COVID-19 on endoscopic surgery in Japan: Analysis of data from the National Clinical Database

Aim

This study aimed to evaluate the impact of the coronavirus disease (COVID-19) pandemic on elective endoscopic surgeries in Japan using the National Clinical Database.

Methods

We retrospectively analyzed the clinicopathological factors and surgical outcomes of laparoscopic cholecystectomy (LC), laparoscopic distal gastrectomy (LDG), and laparoscopic low anterior resection (LLAR) and compared the monthly numbers of each procedure performed in 2020 with those in 2018 and 2019. The degree of infection in prefectures was classified into low and high groups.

Results

In 2020, the number of LCs (except for acute cholecystitis) was 76 079 (93.0% of that in 2019), the number of LDGs was 14 271 (85.9% of that in 2019), and the number of LLARs was 19 570 (88.1% of that in 2019). Although the number of robot-assisted LDG and LLAR cases increased in 2020, the growth rate was mild compared with that in 2019. There was little difference in the number of cases in the degree of infection in the prefectures. The numbers of LC, LDG, and LLAR cases decreased from May to June and recovered gradually. In late 2020, the proportion of T4 and N2 cases of gastric cancer and the number of T4 cases of rectal cancer increased compared with those in 2019. There was little difference between the proportions of postoperative complications and mortality in the three procedures between 2019 and 2020.

Conclusion

The number of endoscopic surgeries decreased in 2020 as a result of the COVID-19 pandemic. However, the procedures were performed safely in Japan.

Updating the Predictive Models for Mortality and Morbidity after Low Anterior Resection Based on the National Clinical Database

INTRODUCTION

We previously developed risk models for mortality and morbidity after low anterior resection using a nationwide Japanese database. However, the milieu of low anterior resection in Japan has undergone drastic changes since then. This study aimed to construct risk models for 6 short-term postoperative outcomes after low anterior resection, i.e., in-hospital mortality, 30-day mortality, anastomotic leakage, surgical site infection except for anastomotic leakage, overall postoperative complication rate, and 30-day reoperation rate.

METHODS

This study enrolled 120,912 patients registered with the National Clinical Database, who underwent low anterior resection between 2014 and 2019. Multiple logistic regression analyses were performed to generate predictive models of mortality and morbidity using preoperative information, including the TNM stage.

RESULTS

We developed new risk prediction models for the overall postoperative complication and 30-day reoperation rates for low anterior resection, which were absent from the previous version. The concordance indices for each endpoint were 0.82 for in-hospital mortality, 0.79 for 30-day mortality, 0.64 for anastomotic leakage, 0.62 for surgical site infection besides anastomotic leakage, 0.63 for complications, and 0.62 for reoperation. The concordance indices of all four models included in the previous version showed improvement.

CONCLUSION

This study successfully updated the risk calculators for predicting mortality and morbidity after low anterior resection using a model based on vast nationwide Japanese data.

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.

Skill-qualified surgeons positively affect short-term outcomes after laparoscopic gastrectomy for gastric cancer: a survey of the National Clinical Database of Japan

BACKGROUND

Proficiency of the operating surgeon is one of the most critical factors potentially associated with reductions in complications and surgery-related mortality. With video-rating systems having shown potential for assessing laparoscopic surgeons' proficiency, the Endoscopic Surgical Skill Qualification System (ESSQS) was developed by the Japan Society for Endoscopic Surgery to subjectively assess the proficiency of laparoscopic surgeons by rating applicants' non-edited case videos. We conducted a study to evaluate how ESSQS skill-qualified (SQ) surgeon involvement influences short-term outcomes of laparoscopic gastrectomy performed for gastric cancer.

METHODS

Data from the National Clinical Database regarding laparoscopic distal and total gastrectomy performed for gastric cancer between January 2016 and December 2018 were analyzed. Operative mortality, defined as 30-day mortality or 90-day in-hospital mortality, and anastomotic leakage rates were compared per involvement vs. non-involvement of an SQ surgeon. Outcomes were also compared per involvement of a gastrectomy-, colectomy-, or cholecystectomy-qualified surgeon. The association between the area of qualification and operative mortality/anastomotic leakage was also analyzed with a generalized estimating equation logistic regression model used to account for patient-level risk factors and institutional differences.

RESULTS

Of 104,093 laparoscopic distal gastrectomies, 52,143 were suitable for inclusion in the study; 30,366 (58.2%) were performed by an SQ surgeon. Of 43,978 laparoscopic total gastrectomies, 10,326 were suitable for inclusion; 6501 (63.0%) were performed by an SQ surgeon. Gastrectomy-qualified surgeons outperformed non-SQ surgeons in terms of both operative mortality and anastomotic leakage. They also outperformed cholecystectomy- and colectomy-qualified surgeons in terms of operative mortality or anastomotic leakage in distal and total gastrectomy, respectively.

CONCLUSION

The ESSQS appears to discriminate laparoscopic surgeons who can be expected to achieve significantly improved gastrectomy outcomes.

Clinical significance of postoperative subcutaneous emphysema after video-assisted thoracoscopic surgery for esophageal cancer

BACKGROUND

Postoperative subcutaneous emphysema (SE) is a possible complication of thoracoscopic or laparoscopic surgery. This study investigated the risk factors and clinical significance of SE after video-assisted thoracoscopic surgery for esophageal cancer (VATS-e).

METHODS

This study included 135 patients who underwent VATS-e with artificial CO2 pneumothorax. Based on the X-ray images on the first postoperative day, patients were divided into two groups: N/L group (no SE or SE localized at the thoracic area, n = 65) and SE group (SE extended to the cervical area, n = 70). We compared clinicopathological features, surgical findings, and short-term outcomes between the two groups.

RESULTS

In SE group, there were more patients who received neoadjuvant chemotherapy compared to N/L group. SE group had significantly lower preoperative body mass index. SE group had more frequently two-lung ventilation than N/L group. Multivariate analysis demonstrated that low BMI, NAC, and two-lung ventilation were independent risk factors for SE extended to the cervical area. Although pulmonary complication was relatively frequent in SE group, there were no significant differences in surgical outcomes between two groups, and all patients had SE disappeared within 21 days without serious complications.

CONCLUSIONS

Despite extension to the cervical area, SE had a modest impact on the short-term result of VATS-e with artificial CO2 pneumothorax.

Risk stratification of anastomotic stricture using early postoperative endoscopic and computed tomography findings in patients undergoing esophagectomy with cervical esophagogastric anastomosis for esophageal cancer

Anastomotic stricture (AS) is one of the major complications after esophagectomy for esophageal cancer. We have previously reported that severe mucosal degeneration (MD) of the anastomotic site was associated with the incidence of AS. Meanwhile, there are few reports to correlate anastomotic internal circumference (AIC) with computed tomography (CT) with the incidence of AS. Therefore, this study was conducted to clarify the correlation of early postoperative endoscopic and CT findings with the incidence of AS. We assessed 205 patients who underwent esophagectomy. We then divided them into the non-AS group (n = 164) and the AS group (n = 41) and compared their background data and intraoperative and postoperative outcomes. We also evaluated the risk factors for AS using logistic regression model. Multivariate analysis revealed small AIC (P = 0.003; OR = 4.400; 95% CI = 1.650-11.700) and severe MD (P < 0.001; OR = 7.200; 95% CI = 2.650-19.600) as the independent risk factors for AS development. We also stratified the patients into the following four groups according to the incidence of AS: low-risk (normal AIC and intact or mild MD, 6.2%), intermediate-risk (small AIC and intact or mild MD, 29.4%), high-risk (normal AIC and severe MD, 42.9%), and very high-risk (small AIC and severe MD, 61.1%). Early postoperative endoscopic and CT findings were useful in predicting the development of AS after esophagectomy.

Prevalence and safety of robotic surgery for gastrointestinal malignant tumors in Japan

Aim

The National Health Insurance system has reimbursed robotic gastrointestinal surgery since April 2018 in Japan. Additionally, strict facility and surgeon standards were established by the government and the academic society. This study aimed to evaluate the prevalence and safety of robotic surgery using a Japanese nationwide web-based database.

Methods

Patients who underwent the following robotic surgeries for malignant tumors in 2018 were included: esophagectomy (RE), total gastrectomy (RTG), distal gastrectomy (RDG), proximal gastrectomy (RPG), low anterior resection (RLAR), and rectal resections other than RLAR (RRR). The number of cases and surgical mortality rates each month were calculated to evaluate the prevalence and safety of robotic procedures.

Results

A total of 3281 patients underwent robotic gastrointestinal surgery. The monthly number of robotic surgeries nearly doubled in April 2018 when they were initially reimbursed by the National Health Insurance system. Operative mortality rates were 0.9%, 0.4%, 0.2%, and 2.8% for RE (n = 330), RTG (n = 239), RDG (n = 1167), and RPG (n = 109), respectively. No mortality was observed in RLAR (n = 1062) or RRR (n = 374).

Conclusion

Robotic surgery for gastrointestinal malignant tumors was safely introduced into daily clinical practice along with rigorous surgeon and facility standards in Japan.

A survey of the clinical outcomes of cervical esophageal carcinoma surgery focusing on the presence or absence of laryngectomy using the National Clinical Database in Japan

BACKGROUND

One upside of cervical esophageal carcinoma is that radical surgery can be performed by laryngectomy, even for tumors with tracheal invasion. However, this approach drastically reduces the quality of life, such as by losing the vocal function. Cervical esophageal carcinoma is rare, and no comprehensive reports have described the current state of surgery. Using a Japanese nationwide web-based database, we analyzed the surgical outcomes of cervical esophageal carcinoma to evaluate the impact of larynx-preserving surgery.

METHODS

Based on the Japan National Clinical Database, 215 surgically treated cases of cervical esophageal carcinoma between January 1, 2018, and December 31, 2019, were enrolled. Clinical outcomes were compared between the larynx-preserved group and the laryngectomy group.

RESULTS

Ninety-four (43.7%) patients underwent larynx-preserving surgery. A total of 177 (82.3%) patients underwent free jejunum reconstruction. More T4b patients and more patients who underwent preoperative radiotherapy were in the laryngectomy group. There were no significant differences in the frequency and the severity of morbidities between the two groups. However, in the laryngectomy group, in-hospital death within 30 days after surgery was observed in 1 patient, and the postoperative hospital stay was significantly longer (P = 0.030). In the larynx-preserved group, recurrent nerve paralysis was observed in 24.5%. Re-operation (35.3%, P = 0.016), re-intubation (17.6%, P = 0.019) and tracheal necrosis (17.6%, P = 0.028) were significantly more frequent in patients who underwent pharyngolaryngectomy with total esophagectomy and gastric tube reconstruction than in others.

CONCLUSION

Larynx-preserving surgery was therefore considered to be feasible because it was equivalent to laryngectomy regarding the short-term surgical outcomes.

Comparison of short term surgical outcomes of male and female gastrointestinal surgeons in Japan: retrospective cohort study

OBJECTIVE

To compare short term surgical outcomes between male and female gastrointestinal surgeons in Japan.

DESIGN

Retrospective cohort study.

SETTING

Data from the Japanese National Clinical Database (includes data on >95% of surgeries performed in Japan) (2013-17) and the Japanese Society of Gastroenterological Surgery.

PARTICIPANTS

Male and female surgeons who performed distal gastrectomy, total gastrectomy, and low anterior resection.

MAIN OUTCOME MEASURES

Surgical mortality, surgical mortality combined with postoperative complications, pancreatic fistula (distal gastrectomy/total gastrectomy only), and anastomotic leakage (low anterior resection only). The association of surgeons' gender with surgery related mortality and surgical complications was examined using multivariable logistic regression models adjusted for patient, surgeon, and hospital characteristics.

RESULTS

A total of 149 193 distal gastrectomy surgeries (male surgeons: 140 971 (94.5%); female surgeons: 8222 (5.5%)); 63 417 gastrectomy surgeries (male surgeons: 59 915 (94.5%); female surgeons: 3502 (5.5%)); and 81 593 low anterior resection procedures (male surgeons: 77 864 (95.4%);female surgeons: 3729 (4.6%)) were done. On average, female surgeons had fewer post-registration years, operated on patients at higher risk, and did fewer laparoscopic surgeries than male surgeons. No significant difference was found between male and female surgeons in the adjusted risk for surgical mortality (adjusted odds ratio 0.98 (95% confidence interval 0.74 to 1.29) for distal gastrectomy; 0.83 (0.57 to 1.19) for total gastrectomy; 0.56 (0.30 to 1.05) for low anterior resection), surgical mortality combined with Clavien-Dindo grade ≥3 complications (adjusted odds ratio 1.03 (0.93 to 1.14) for distal gastrectomy; 0.92 (0.81 to 1.05) for total gastrectomy; 1.02 (0.91 to 1.15) for low anterior resection), pancreatic fistula (adjusted odds ratio 1.16 (0.97 to 1.38) for distal gastrectomy; 1.02 (0.84 to 1.23) for total gastrectomy), and anastomotic leakage (adjusted odds ratio 1.04 (0.92 to 1.18) for low anterior resection).

CONCLUSION

This study found no significant adjusted risk difference in the outcomes of surgeries performed by male versus female gastrointestinal surgeons. Despite disadvantages, female surgeons take on patients at high risk. Greater access to surgical training for female physicians is warranted in Japan.

Surgical Experience Disparity Between Male and Female Surgeons in Japan

Question

Does gender disparity exist in the number of surgical experiences among male and female surgeons in Japan?

Findings

In this cross-sectional study covering 1 147 068 total operations in 6 surgical fields performed between 2013 and 2017, surgical experience was classified by surgeons’ gender and years of experience. The number of operations per surgeon was lower for female compared with male surgeons, except in the first 2 years after medical registration; this gender gap widened as the difficulty level of surgery increased.

Meaning

The findings indicate a marked disparity in the surgical experience of female and male surgeons in Japan.

Importance

Women are vastly underrepresented in surgical leadership and management in Japan. The lack of equal opportunities for surgical training is speculated to be the main reason for this disparity; however, this hypothesis has not been investigated thus far.

Objective

To examine gender disparity in the number of surgical experiences among Japanese surgeons.

Design, Setting, and Participants

This retrospective, multicenter cross-sectional study used data from the National Clinical Database, which contains more than 95% of all surgical procedures in Japan. Participants included male and female gastroenterological surgeons who performed appendectomy, cholecystectomy, right hemicolectomy, distal gastrectomy, low anterior resection, and pancreaticoduodenectomy between January 1, 2013, and December 31, 2017.

Exposures

Differences in the number of surgical experiences between male and female surgeons.

Main Outcomes and Measures

The primary outcomes were the total number of operations and number of operations per surgeon by gender and years of experience. Data were analyzed from March 18 to August 31, 2021.

Results

Of 1 147 068 total operations, 83 354 (7.27%) were performed by female surgeons and 1 063 714 (92.73%) by male surgeons. Among the 6 operative procedures, the percentage of operations performed by female surgeons were the highest for appendectomy (n = 20 648 [9.83%]) and cholecystectomy (n = 41 271 [7.89%]) and lowest for low anterior resection (n = 4507 [4.57%]) and pancreaticoduodenectomy (n = 1329 [2.64%]). Regarding the number of operations per surgeon, female surgeons had fewer surgical experiences for all 6 types of operations in all years after registration, except for appendectomy and cholecystectomy in the first 2 years after medical registration. The largest gender disparity for each surgical procedure was 3.17 times more procedures for male vs female surgeons for appendectomy (at 15 years after medical registration), 4.93 times for cholecystectomy (at 30-39 years), 3.65 times for right hemicolectomy (at 30-39 years), 3.02 times for distal gastrectomy (at 27-29 years), 6.75 times for low anterior resection (at 27-29 years), and 22.2 times for pancreaticoduodenectomy (at 30-39 years).

Conclusions and Relevance

This cross-sectional study found that female surgeons had less surgical experience than male surgeons in Japan, and this gap tended to widen with an increase in years of experience, especially for medium- and high-difficulty operations. Gender disparity in surgical experience needs to be eliminated, so that female surgeons can advance to leadership positions.

Clinicopathological features of male patients with breast cancer based on a nationwide registry database in Japan

BACKGROUND

Male breast cancer (MBC) is rare; however, its incidence is increasing. There have been no large-scale reports on the clinicopathological characteristics of MBC in Japan.

METHODS

We investigated patients diagnosed with breast cancer in the Japanese National Clinical Database (NCD) between January 2012 and December 2018.

RESULTS

A total of 594,316 cases of breast cancer, including 3780 MBC (0.6%) and 590,536 female breast cancer (FBC) (99.4%), were evaluated. The median age at MBC and FBC diagnosis was 71 (45-86, 5-95%) and 60 years (39-83) (p < 0.001), respectively. MBC cases had a higher clinical stage than FBC cases: 7.4 vs. 13.3% stage 0, 37.2 vs. 44.3% stage I, 25.6 vs. 23.9% stage IIA, 8.8 vs. 8.4% stage IIB, 1.9 vs. 2.4% stage IIIA, 10.1 vs. 3.3% stage IIIB, and 1.1 vs. 1.3% stage IIIC (p < 0.001). Breast-conserving surgery was more frequent in FBC (14.6 vs. 46.7%, p = 0.02). Axillary lymph node dissection was more frequent in MBC cases (32.9 vs. 25.2%, p < 0.001). Estrogen receptor(ER)-positive disease was observed in 95.6% of MBC and 85.3% of FBC cases (p < 0.001). The HER2-positive disease rates were 9.5% and 15.7%, respectively (p < 0.001). Comorbidities were more frequent in MBC (57.3 vs. 32.8%) (p < 0.001). Chemotherapy was less common in MBC, while endocrine therapy use was similar in ER-positive MBC and FBC. Perioperative radiation therapy was performed in 14.3% and 44.3% of cases.

CONCLUSION

Japanese MBC had an older age of onset, were more likely to be hormone receptor-positive disease, and received less perioperative chemotherapy than FBC.

Intraoperative nerve monitoring during esophagectomy reduces the risk of recurrent laryngeal nerve palsy

BACKGROUND

Despite the risk of recurrent laryngeal nerve (RLN) palsy during esophagectomy, no established method of monitoring RLN injury is currently available.

METHODS

This study included 187 patients who underwent esophagectomy between 2011 and 2018. Among these, intraoperative nerve monitoring (IONM) was done in 142 patients (IONM group), while the remaining 45 patients underwent conventional surgery without IONM (control group). We investigated the incidence of postoperative complications with regard to the use of IONM.

RESULTS

The overall incidence of postoperative RLN palsy was 28% (52/187). The IONM group showed a significantly lower incidence of postoperative RLN palsy as compared to that in the control group (p = 0.004). The overall incidence of postoperative pneumonia was 22% (41/187) in those with Clavien-Dindo (CD) classification beyond grade 2. There were no significant differences between the incidence of any grade of postoperative pneumonia and the use of IONM (p = 0.195 and 0.333; CD > 2 and > 3, respectively). Multivariate analysis demonstrated that tumors in the upper third [odds ratio (OR) 3.12; 95% confidence interval (CI) 1.04-9.29] and lack of IONM use (OR 2.51; 95% CI 1.17-5.38) were independent factors causing postoperative RLN palsy after esophagectomy.

CONCLUSION

IONM helps to reduce the risk of postoperative RLN palsy after esophageal cancer surgery.

Safe implementation of robotic gastrectomy for gastric cancer under the requirements for universal health insurance coverage: a retrospective cohort study using a nationwide registry database in Japan

BACKGROUND

Robotic gastrectomy (RG) has increased since being covered by universal health insurance in 2018. However, to ensure patient safety the operating surgeon and facility must meet specific requirements. We aimed to determine whether RG has been safely implemented under the requirements for universal health insurance in Japan.

METHODS

Data of consecutive patients with primary gastric cancer who underwent minimally invasive total or distal gastrectomy-performed by a surgeon certified by the Japan Society for Endoscopic Surgery (JSES) endoscopic surgical skill qualification system (ESSQS) between October 2018 and December 2019-were extracted from the gastrointestinal surgery section of the National Clinical Database (NCD). The primary outcome was morbidity over Clavien-Dindo classification grade IIIa. Patient demographics and hospital volume were matched between RG and laparoscopic gastrectomy (LG) using propensity score-matched analysis (PSM), and the short-term outcomes of RG and LG were compared.

RESULTS

After PSM, 2671 patients who underwent RG and 2671 who underwent LG were retrieved (from a total of 9881), and the standardized difference of all the confounding factors reduced to 0.07 or less. Morbidity rates did not differ between the RG and LG patients (RG, 4.9% vs. LG, 3.9%; p = 0.084). No difference was observed in 30-day mortality (RG, 0.2% vs. LG, 0.1%; p = 0.754). The reoperation rate was greater following RG (RG, 2.2% vs. LG, 1.2%; p = 0.004); however, the duration of postoperative hospitalization was shorter (RG, 10 [8-13] days vs. LG, 11 [9-14] days; p < 0.001).

CONCLUSIONS

Insurance-covered RG has been safely implemented nationwide.

The safe performance of robotic gastrectomy by second-generation surgeons meeting the operating surgeon's criteria in the Japan Society for Endoscopic Surgery guidelines

BACKGROUND

Robotic gastrectomy (RG) for gastric cancer (GC) has gradually gained nationwide prominence following 2011 guidelines from the Japan Society for Endoscopic Surgery (JSES), including the surgeons' criteria and the proctor system. In this retrospective study, we examined the short-term outcomes of the initial series of RGs performed by second-generation operating surgeons trained within our institute.

METHODS

Between January 2017 and April 2020, five surgeons each performed RG in 20 patients with clinical stage III or lower GC in accordance with the JSES guidelines. We evaluated both the rate of Clavien-Dindo grade II or higher morbidities and the console time required to reach the learning plateau via cumulative summation (CUSUM) analysis.

RESULTS

We observed no mortality and 3% of morbidity following RG. Both the operative time (430 vs 387.5 min, P = 0.019) and console time (380 vs . 331.5 min, P = 0.009) were significantly shorter in the second 10 cases than in the initial 10 cases. We observed a remarkable trend in cases of distal gastrectomy (DG), in which the total operative time and console time were significantly shorter in the later cases. Our CUSUM analysis revealed that seven cases were required to achieve a learning plateau in RG when confined to DG.

CONCLUSIONS

Non-expert RG surgeons meeting the operating surgeon's criteria from the JSES who had trained under an expert RG surgeon safely performed RG in an initial 20 cases.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2019

BACKGROUND

We aimed to present the 2019 annual report of the gastroenterological section of the National Clinical Database (NCD).

METHODS

We reviewed 609,589 cases recorded in 2019 and 5,029,764 cases registered from 2011 to 2019 for the 115 selected gastroenterological surgical procedures.

RESULTS

The main features of gastroenterological surgery in Japan were similar to those described in the 2018 annual report, namely, that 1) operative numbers gradually increased in all procedures, except gastrectomy and hepatectomy, which decreased in these years; 2) in all eight major gastroenterological surgeries, the age distribution tended toward older patients; 3) the morbidity of esophagectomy, hepatectomy, and pancreaticoduodenectomy increased, but mortality was minimized in all procedures; 4) all eight major gastroenterological procedures have increasingly been performed under laparoscopy; and 5) board-certified surgeons were increasingly involved. These trends in recent years were more prominent in 2019.

CONCLUSIONS

Thanks to the continuous cooperation and dedication of the surgeons, medical staff, and surgical clinical reviewers who registered the clinical data into the NCD, it is possible to understand the comprehensive landscape of surgery in Japan and to disclose new evidence in this field. The Japanese Society of Gastroenterological Surgery will continue to promote the value of this database and encourage the use of feedback and clinical studies using the NCD, now and in the future. Generating further approaches to surgical quality improvement are important directions for future research.

Association between age and short-term outcomes of gastroenterological surgeries in older patients: an analysis using the National Clinical Database in Japan

PURPOSE

The association between advanced age and postoperative morbidity and mortality after major gastroenterological surgeries remains unclear. This study aimed to assess the association between old age and the short-term postoperative outcomes of gastroenterological surgeries.

METHODS

We evaluated 327,642 patients who underwent any of the seven major gastroenterological surgeries-esophagectomy, total gastrectomy, distal gastrectomy, right hemicolectomy, low anterior resection, hepatectomy, and pancreatoduodenectomy-and were registered with the Japanese national surgical registry between January 2011 and December 2013. Perioperative characteristics, frequency/nature of postoperative morbidities, and postoperative mortality were compared according to age at the time of surgery.

RESULTS

Overall, 18% (59,182/327,642) of the entire cohort were aged ≥ 80 years. The overall mortality rates in the entire cohort and in those aged ≥ 80 years were 1.7% and 3.3%, respectively. The postoperative mortality increased with increasing age for all procedures, with the trend persisting even after adjusting for various confounding factors. The incidence of postoperative pneumonia increased with increasing age, and with all procedures, except esophagectomy, subjects aged ≥ 80 years had a markedly higher risk of developing postoperative pneumonia than those aged < 60 years.

CONCLUSION

Advanced age is associated with significantly worse short-term outcomes in older patients undergoing gastroenterological surgeries. However, we could not identify any distinct cutoff age beyond which major gastroenterological surgery could be considered as being contraindicated. The mortality risk should be carefully considered before recommending major gastroenterological surgeries for older patients.

Risk stratification of anastomotic leakage using eGFR and FIB-4 index in patients undergoing esophageal cancer surgery

PURPOSE

Renal insufficiency and liver cirrhosis are identified as independent risk factors for anastomotic leakage (AL) after esophagectomy. However, research evaluating the incidence of AL using quantitative data to measure renal function and liver fibrosis remain to be limited. Therefore, this study was conducted to evaluate postoperative AL after esophagectomy using estimated glomerular filtration rate (eGFR) and fibrosis-4 (FIB-4) index.

METHODS

In total, 184 patients who underwent esophagectomy were included in this study; then, they were divided into the non-AL group (n = 161) and AL group (n = 23), after which their background data and intraoperative and postoperative outcomes were compared. In addition, risk factors for AL were evaluated using a logistic regression model.

RESULTS

Preoperative body mass index of ≥21.5 kg/m², hemoglobin A1c level of ≥7.3%, FIB-4 index of ≥1.44, and eGFR of <59 ml/min/1.73 m² were found to be significantly frequent in the AL group compared with the non-AL group. Multivariate analysis revealed FIB-4 index of ≥1.44 (p = 0.013; OR, 3.780; 95% CI, 1.320-10.800) and eGFR of <59 ml/min/1.73 m² (p = 0.018; OR, 3.110; 95% CI, 1.220-8.020) as the independent risk factors for AL. In addition, we stratified the patients into three groups based on the incidence of AL as follows: low risk (5.5%, low FIB-4 index), intermediate risk (13.0%, high FIB-4 index and eGFR), and high risk (37.5%, high FIB-4 index and low eGFR).

CONCLUSION

Preoperative eGFR and FIB-4 index were found to be useful markers to predict AL after esophagectomy.

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.

Surgically treated gastric cancer in Japan: 2011 annual report of the national clinical database gastric cancer registry

BACKGROUND

The National Clinical Database (NCD) nationwide registry program of gastric cancer started in 2018. The purpose of this study was to report the treatment results of the NCD registry in the form of treatment results of the real world in Japan.

METHODS

Patients' characteristics, tumor features, treatments, and outcomes were collected using a web-based data entry system. We analyzed the initial NCD database for data on surgically treated gastric cancer patients in 2011.

RESULTS

A total of 30,257 patients with malignant gastric tumors were enrolled by the NCD registry program from 501 hospitals in all 47 prefectures. Of these, the status of data entry was not approved in 8.8% of the registered data, and follow-up information was missing in 1.2% of the approved cases. Excluding 1777 cases, which were not resected for primary gastric cancer, 25,306 resected cases included 44.4% of stomach surgeries recorded in the NCD. The 5 year survival rate of the resected cases was 71.3% and the operative mortality rate was 0.41%. The stage-specific 5 year survival rates were as follows: 89.6% for stage IA, 83.8% for stage IB, 77.3% for stage IIA, 69.1% for stage IIB, 58.7% for stage IIIA, 44.1% for stage IIIB, 30.1% for stage IIIC, and 13.4% for stage IV.

CONCLUSIONS

The NCD gastric cancer registry program demonstrated validity for database construction. The gastric cancer registry is expected to become a nationwide registry with the dissemination of data entry system and method in the NCD.

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.

Japanese Current Status of Curative-Intent Surgery for Malignant Pleural Mesothelioma

BACKGROUND

Few reports about surgical outcomes in malignant pleural mesothelioma (MPM) were based on reliable nationwide databases. Here we analyzed the incidence, surgical outcome, and operative risk factors using Japanese nationwide database.

METHODS

Characteristics and perioperative data from 622 patients who underwent curative-intent surgery for MPM between January 2014 and December 2017 were recorded from National Clinical Database of Japan. We analyzed the incidence, surgical outcomes, and risk factors for surgical complications after two surgical procedures (extrapleural pneumonectomy, EPP; and pleurectomy/decortication, P/D).

RESULTS

During 4 years, EPP was performed in 279 patients and P/D in 343. EPP was more frequently performed in less-MPM-experienced institutions, while P/D was more frequently performed in well-MPM-experienced institutions (P < .001), especially in high-volume centers with more than 10 cases during this period. P/D was more frequently performed, especially in high-volume centers. The morbidity rates were 45.2% in EPP and 35.9% in P/D. Heart failure and pneumonia were most frequent in EPP, while prolonged air leakage was most frequent in P/D. Thirty-day- and in-hospital mortality rates were 1.1% and 3.2% (EPP) and 1.2% and 3.2% (P/D), respectively. Regression analyses revealed that higher age (>65 years) was associated with operative complications in EPP (odds ratio, OR: 3.56 [1.26-8.56]), whereas no risk factor was observed in P/D.

CONCLUSIONS

In Japanese nationwide annual database, P/D was more frequently performed, especially in high-volume centers. Morbidity was higher in EPP than P/D; however, the mortality rates were quite low in Japan regardless surgical procedures.

Laparoscopic Versus Open Appendectomy for Acute Appendicitis in Children: a Nationwide Retrospective Study on Postoperative Outcomes

PURPOSE

Our aim was to compare postoperative outcomes of laparoscopic and open appendectomies for acute appendicitis in children under the circumstance of widespread use of laparoscopic surgery.

METHOD

This study included data on laparoscopic and open appendectomies in children with acute appendicitis from the National Clinical Database, which is a Japanese nationwide surgical database, in 2015. The occurrence rates of complications within 30 days after the surgery and postoperative hospital stay were compared by univariate and multivariate analyses. p < 0.05 was considered statistically significant.

RESULTS

This study included 4489 appendectomies, of which 3166 surgeries (70.5%) were performed laparoscopically. Appendectomy was performed for complicated and uncomplicated appendicitis in 1765 (39.3%) and 2724 cases (60.7%), respectively. Postoperative complications within 30 days were observed in 246 operations (5.5%). Organ-space surgical site infection (SSI), deep wound SSIs, and superficial wound SSIs were observed in 2.3%, 1.0%, and 2.4% of operations, respectively. On multivariate analysis, the incidence of postoperative complications (odds ratio 1.21, 95% CI 0.90-1.64, p = 0.207) and the length of hospital stay (median 4 days in both groups, p = 0.835) were not significantly different between patients who underwent laparoscopic or open appendectomy. Subgroup analysis in complicated and uncomplicated appendicitis cases also demonstrated no significant differences in the incidence of postoperative complications between those who underwent laparoscopic or open appendectomy.

CONCLUSION

This study suggested that the occurrence of postoperative complication and the length of hospital stay in pediatric patients who underwent laparoscopic appendectomy are similar with those in pediatric patients who underwent open appendectomy for acute appendicitis.

Differential impacts of postoperative complications on patients' survival in completely resected non-small-cell lung cancer

OBJECTIVE

The aim of this study was to investigate the effects of inflammatory respiratory complications on long-term survival in patients with resected non-small cell lung cancer. We defined inflammatory respiratory complications to include the following six conditions: pneumonia, empyema, bronchial fistula, respiratory dysfunction, acute interstitial pneumonia, and atelectasis.

METHODS

Part of the National Clinical Database was linked to our prospective database from 2014 to 2017. Linkage was achieved for 866 patients. The Kaplan-Meier method was used to evaluate the overall, relapse-free, and cancer-related survival. The Cox proportional hazard model was used to analyze the impact of each complication.

RESULTS

Of the 736 patients included in the study, 149 had complications. The 5-year overall and cancer-specific survival rates were significantly lower in patients with inflammatory respiratory complications. The Cox proportional hazard model showed that the inflammatory respiratory complications had a significant impact on overall survival (hazard ratio 2.48, 95% confidence interval 1.41-4.38) but not air leak (hazard ratio 1.38, 95% confidence interval 0.70-2.70).

CONCLUSIONS

Our study shows the differential impact of each complication on the survival of patients with non-small cell lung cancer. The presence of inflammatory respiratory complications was the only predictor of poor overall survival.

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.

Improved Mortality, Morbidity and Long-term Outcome after Anatomical Hepatectomy with the Glissonean Pedicle Approach in Patients with Hepatocellular Carcinoma: 30 years' Experience at a Single Institute

OBJECTIVE

We evaluated the morbidity and mortality after anatomical hepatectomy with the Glissonean pedicle approach, and long-term outcomes in relation to the morbidity in patients with hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

The mortality, morbidity, and long-term outcomes were evaluated retrospectively.

METHODS

1953 patients with HCC underwent various anatomical hepatectomies with the Glissonean pedicle approach between 1985 and 2014. The mortality (30-day and 90-day) and morbidity (Clavien-Dindo class IIIa or higher) were evaluated among six 5-year eras (1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, 2010-2014).

RESULTS

460 patients (24%) showed morbidity, and the overall 30-day and 90-day mortality rates were 1.8% and 3.3%, respectively. The 30-day (3.9%, 3.0%, 1.8%, 1.3%, 0.3%, 0.5%: p = 0.0074) and 90-day mortality (6.0%, 4.3%, 3.8%, 2.8%, 2.2%, 1.4%: p = 0.0445) significantly improved over the eras. Blood loss >2 L (Odd ratio: 11.808, p = 0.0244) was an independent risk factor for 30-day mortality, and blood loss >2 L (Odd ratio: 4.046, p = 0.0271) and bile leakage (Odd ratio: 2.122, p = 0.0078) were independent risk factors for 90-day mortality on multivariate analysis. Morbidity was significant independent prognostic factors for overall survival (Relative Risk: 2.129, p < 0.0001) and recurrence-free survival (Relative Risk: 1.299, p < 0.0001) in patients with HCC.

CONCLUSIONS

Anatomical hepatectomy with the Glissonean pedicle approach was achieved safely in patients with HCC. For more safety and longer survival, blood loss, bile leakage, and morbidity should be reduced. Long-term outcomes after anatomical hepatectomy with the Glissonean pedicle approach in patients with HCC have been improved over 30 years with gradually less mortality and morbidity due to decreases in blood loss>2L and bile leakage.

Mortality calculator as a possible prognostic predictor of overall survival after gastrectomy in elderly patients with gastric cancer

Background

The number of elderly patients with gastric cancer has been increasing. Most elderly patients have associated reduced physiologic functions that can sometimes become an obstacle to safe surgical treatment. The National Clinical Database Risk Calculator, which based on a large Japanese surgical database, provides predicted mortality and morbidity in each case as the surgical-related risks. The purpose of this study was to investigate the clinical significance of the risk for operative mortality (NRC-mortality), as calculated by the National Clinical Database Risk Calculator, during long-term follow-up after gastrectomy for elderly patients with gastric cancer.

Methods

We enrolled 73 patients aged ≥ 80 years and underwent gastrectomy at our institution. Their surgical risk was evaluated based on the NRC-mortality. Several clinicopathologic factors, including NRC-mortality, were selected and analyzed as the possible prognostic factors for elderly patients who have undergone gastrectomy for gastric cancer. Statistical analysis was performed using the log-rank test and Cox proportional hazard model.

Results

NRC-mortality ranged from 0.5 to 10.6%, and the median value was 1.7%. Dividing the patients according to mortality, the overall survival was significantly worse in the high mortality group (≥ 1.7%, n = 38) than in the low mortality group (< 1.7%, n = 35), whereas disease-specific survival was not different between the two groups. In the Cox proportional hazard model, multivariate analysis revealed NRC-mortality, performance status, and surgical procedure as the independent prognostic factors for overall survival. For disease-specific survival, the independent prognostic factors were performance status and pathological stage but not NRC-mortality.

Conclusion

The NRC-mortality might be clinically useful for predicting both surgical mortality and overall survival after gastrectomy in elderly patients with gastric cancer.

Geriatric Risk Prediction Models for Major Gastroenterological Surgery using the National Clinical Database in Japan: A Multicenter Prospective Cohort Study

OBJECTIVES

To investigate the effect of geriatric variables on five newly added outcomes and create risk models for predicting these outcomes.

SUMMARY BACKGROUND DATA

Because there is a current lack of geriatric research focusing on geriatric outcomes using a national surgical database in Japan, there is a need to investigate outcomes associated with major gastroenterological surgery using these data.

METHODS

This multicenter prospective cohort study was conducted at 26 surgery departments across 21 institutions in Japan using the National Clinical Database (NCD) surgical registry. In total, 22 new geriatric variables were imported from the ACS NSQIP geriatric pilot study. The following five geriatric outcomes were defined: 1) postoperative delirium, 2) physical function on postoperative day 30, 3) fall risk on discharge, 4) discharge other than home with social service, and 5) functional decline on discharge, and geriatric risk prediction models for major gastroenterological surgery were created.

RESULTS

Between January 2018 and December 2018, data on 3,981 procedures from seven major gastroenterological surgeries were collected and analyzed. Older age and preoperative geriatric variables (Origin status from home, History of dementia, Use of mobility aid, Fall history, and Not competent on admission) were strongly associated with postoperative outcomes. Geriatric risk prediction models for these outcomes were created, with C-statistic values ranging from 0.74 to 0.90, demonstrating model validity and sufficiency of fit.

CONCLUSIONS

The risk models for the newly defined five geriatric outcomes that we created can be used in the decision-making process or provision of care in geriatric patients.

Impact of Primary Tumor Location on Survival After Curative Resection in Patients with Colon Cancer: A Meta-Analysis of Propensity Score-Matching Studies

BACKGROUND

Recent retrospective subgroup analyses of patients with unresectable colon cancer (CC) receiving systemic chemotherapy have demonstrated that there is a significant difference in treatment outcome between patients with right-sided CC (RSCC) and those with left-sided CC (LSCC). However, it is impossible to divide patients with CC randomly into RSCC and LSCC groups before surgery. Therefore, the aim of this study is to explore the impact of primary tumor location (PTL) on survival after curative surgery for patients with CC using propensity score-matching (PSM) studies instead of randomization.

MATERIALS AND METHODS

We performed a comprehensive electronic search of the literature up to January 2019 to identify studies that had used databases allowing comparison of postoperative survival between patients with RSCC and those with LSCC. To integrate the impact of PTL on 5-year overall survival (OS) after curative surgery, a meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected PSM studies.

RESULTS

Five studies involving a total of 398,687 patients with CC were included in this meta-analysis. Among 205,641 patients with RSCC, 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with LSCC, 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5-year OS (RR, 0.98; 95% CI, 0.89-1.07; p = .64; I² = 97%).

CONCLUSION

This meta-analysis has demonstrated that there was no significant difference in 5-year OS between patients with RSCC and those with LSCC after curative resection.

IMPLICATIONS FOR PRACTICE

To integrate the impact of primary tumor location (PTL) on 5-year overall survival (OS) after curative surgery, five propensity score-matching (PSM) studies involving a total of 398,687 patients with colon cancer (CC) were included in this meta-analysis. Among 205,641 patients with right-sided CC (RSCC), 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with left-sided CC (LSCC), 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5-year OS (risk ratio, 0.98; 95% confidence interval, 0.89-1.07; p = .64; I² = 97%).

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.

Current status of surgery for clinical stage IA lung cancer in Japan: analysis of the national clinical database

Purpose

As the number of cases of early lung cancer in Japan grows, an analysis of the present status of surgical treatments for clinical stage IA lung cancer using a nationwide database with web-based data entry is warranted.

Methods

The operative and perioperative data from 47,921 patients who underwent surgery for clinical stage IA lung cancer in 2014 and 2015 were obtained from the National Clinical Database (NCD) of Japan. Clinicopathological characteristics, surgical procedure, mortality, and morbidity were analyzed, and thoracotomy and video-assisted thoracic surgery (VATS) were compared.

Results

The patients comprised 27,208 men (56.8%) and 20,713 women (43.2%); mean age, 69.3 years. Lobectomy was performed in 64.8%, segmentectomy in 15.2%, and wedge resection in 19.8%. The surgical procedures were thoracotomy in 12,194 patients (25.4%) and a minimally invasive approach (MIA) in 35,727 patients (74.6%). MIA was divided into VATS + mini-thoracotomy (n = 13,422, 28.0%) and complete VATS (n = 22,305, 46.5%). The overall postoperative mortality rate was 0.4%, being significantly lower in the MIA group than in the thoracotomy group (0.3% vs 0.8%, P < 0.001).

Conclusions

Our analysis of data from the NCD indicates that MIA has become the new standard treatment for clinical stage IA lung cancer.

Electronic supplementary material

The online version of this article (10.1007/s00595-020-02063-x) contains supplementary material, which is available to authorized users.

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.

Non-robotic minimally invasive gastrectomy as an independent risk factor for postoperative intra-abdominal infectious complications: A single-center, retrospective and propensity score-matched analysis

BACKGROUND

Minimally invasive surgery for gastric cancer (GC) has gained widespread use as a safe curative procedure especially for early GC.

AIM

To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC.

METHODS

Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage III or lower GC and underwent robotic gastrectomy (RG) or laparoscopic gastrectomy (LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity.

RESULTS

Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group (2.5% vs 5.9%, respectively; P = 0.038), while no significant differences were noted for other local or systemic complications. Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463 (1.070-5.682); P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications.

CONCLUSION

The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications.

Feasibility of laparoscopic gastrectomy for patients with poor physical status: a retrospective cohort study based on a nationwide registry database in Japan

BACKGROUND

Laparoscopic gastrectomy (LG) is an established minimally invasive procedure for gastric cancer. However, it is controversial whether LG is useful for patients with poor physical status classified into higher classes of the American Society of Anesthesiologists physical status (ASA-PS) classification. The aim of this study was to determine the feasibility of LG in patients with ASA-PS class ≥ 3.

METHODS

We extracted data for a total of 28,160 patients with an ASA-PS class ≥ 3 who underwent distal or total gastrectomy for gastric cancer between January 2013 and December 2017 from the National Clinical Database Japan society for gastroenterological surgery registry. We developed a propensity score model from baseline demographics and comorbidities and matched patients undergoing LG to those undergoing open gastrectomy (OG) using a 1:1 ratio. Mortality and morbidities (within 30 days and in-hospital) were compared between the 6998 matched patient pairs.

RESULTS

In-hospital mortality was significantly lower in patients undergoing LG than in those undergoing OG (2.3% vs. 3.0%, p = 0.01), while the 30-day mortality was similar (1.6% vs. 1.5%). The length of hospital stay was significantly shorter in the LG group (median, 14 days vs. 17 days, p < 0.001). The LG group had a significantly lower incidence of postoperative complications in patients with any grade complication (20.3% vs. 22.5%, p = 0.002) as well as those with ≥ grade 3 complications (8.7% vs. 9.8%, p = 0.03).

CONCLUSION

LG was associated with decreased in-hospital mortality and a lower incidence of several postoperative complications when compared to OG among patients with poor physical condition.

Definition of the objective threshold of pancreatoduodenectomy with nationwide data systems

BACKGROUND

This study aimed to define an objective evidence-based threshold of high-volume hospitals (HVHs) for pancreatoduodenectomy (PD) using nationwide data systems.

METHODS

A total of 36,453 patients underwent PD in 1,499 hospitals from 2012 to 2015 were collected from the National Clinical Database in Japan. Restricted cubic spline model with risk adjustment was used for definition of an objective evidence-based threshold of HVHs.

RESULTS

The restricted cubic spline curve of 30-day and in-hospital mortality showed a continuous decrease with an increase in hospital volume and plateau phase of mortality was detected between approximately 30 and 50 PDs/year. On the basis of this curve, we defined hospitals ≥30 PDs/year as HVHs and ≤29 PDs/year as non-HVHs. We also sub-classified hospitals <5, 5-29, 30-49, and ≥50 PDs/year as low-volume, intermediate-volume, high-volume, and very high-volume hospitals using the spline curve. The odds ratio (OR) of risk-adjusted mortality decreased as hospital volume increased, with an OR of 0.34 for HVHs and 0.26 for very HVHs compared with low-volume hospitals.

CONCLUSIONS

We consider that this concept is applicable to other high-risk procedures for reducing mortality after these procedures, which could improve medical care and health services.