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

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.

The first detailed annual record on the National Clinical Database Urology Division in Japan: A report on five surgical procedures

OBJECTIVES

The National Clinical Database (NCD) Urology Division commenced registration in April 2018 in Japan. This is the first report to focus on five surgeries for which detailed information is registered.

METHODS

We herein describe annual trends in and the complication grades of the following five surgeries: partial nephrectomy, radical nephrectomy, radical cystectomy, radical prostatectomy, and pyeloplasty, using the NCD. A total of 149 417 patients treated with the five types of surgeries based on NCD data were enrolled in this report.

RESULTS

The number of patients was 55 630 for partial/radical nephrectomy from April 2018 to December 2021, 83 653 for radical prostatectomy from April 2018 to December 2021, and 9342 for radical cystectomy from January 2020 to December 2021. In 2021, partial nephrectomy was performed on 7416 cases, radical nephrectomy on 7739 cases, radical prostatectomy on 22 692 cases, radical cystectomy on 4677 cases, and pyeloplasty on 792 cases.

CONCLUSIONS

The results obtained showed that a robot-assisted or laparoscopic procedure has replaced open surgery as the common approach for all five surgeries. An analysis of NCD data may be useful for understanding trends in surgical procedures across the major field of urology.

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.

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.

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.

[Trends in upper urinary tract reconstruction surgery over a decade based on a multi-center database]

OBJECTIVE

To study the trend of surgical type, surgical procedure and etiological distribution of upper urinary tract repair in recent 10 years.

METHODS

The preoperative and perioperative variables and follow-up data of upper urinary tract reconstruction surgery in RECUTTER (Reconstruction of Urinary Tract: Technology, Epidemiology and Result) database from 2010 to 2021 were searched, collected and analyzed. The surgical type, surgical procedure, duration of hospitalization, time of operation, incidence of short-term complications, and proportion of the patients undergoing reoperations were compared between the two groups of 2010-2017 period and 2018-2021 period.

RESULTS

A total of 1 072 patients were included in the RECUTTER database. Congenital factors and iatrogenic injuries were the main causes of upper urinary tract repair. Among them, 129 (12.0%) patients had open operation, 403 (37.6%) patients had laparoscopic surgery, 322 (30.0%) patients had robot-assisted laparoscopic surgery and 218 (20.3%) patients had endourological procedure. In the last decade, the total number of surgeries showed a noticeable increasing annual trend and the proportion of robot-assisted laparoscopic surgery in 2018-2021 was significantly higher than that in 2010-2017 (P < 0.001). The 1 072 patients included 124 (11.6%) cases of ileal ureter replacements, 440 (41.1%) cases of pyeloplasty, 229 (21.4%) cases of balloon dilation, 109 (10.2%) cases of ureteral reimplantation, 49 (4.6%) cases of boari flap-Psoas hitch surgery, 60 (5.6%) cases of uretero-ureteral anastomosis, 61 (5.7%) cases of lingual mucosal onlay graft ureteroplasty or appendiceal onlay flap ureteroplasty. Pyeloplasty and balloon dilatation had been the main types of surgery, while the proportion of lingual mucosal onlay graft ureteroplasty plus appendiceal onlay flap ureteroplasty had increased significantly in recent years (P < 0.05). In addition, the time of operation was significantly increased (P < 0.05) after 2018, which was considered to be related to the sharp increase in the proportion of robot-assisted laparoscopic surgery. We found that minimally invasive surgery (endourological procedure and robot-assisted laparoscopic surgery) as an independent risk factor (P=0.050, OR=0.472) could reduce the incidence of short-term post-operative complications.

CONCLUSION

We have justified the value of the RECUTTER database, created by the Institute of Urology, Peking University in data support for clinical research work, and provided valuable experience for the construction of other multi-center databases at home and abroad. In recent 10 years, we have observed that, in upper urinary tract reconstruction surgery, the surgery type tends to be minimally invasive and the surgery procedure tends to be complicated, suggesting the superiority of robot-assisted laparoscopic surgery.

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.

Machine learning methods to predict presence of residual cancer following hysterectomy

Surgical management for gynecologic malignancies often involves hysterectomy, often constituting the most common gynecologic surgery worldwide. Despite maximal surgical and medical care, gynecologic malignancies have a high rate of recurrence following surgery. Current machine learning models use advanced pathology data that is often inaccessible within low-resource settings and are specific to singular cancer types. There is currently a need for machine learning models to predict non-clinically evident residual disease using only clinically available health data. Here we developed and tested multiple machine learning models to assess the risk of residual disease post-hysterectomy based on clinical and operative parameters. Data from 3656 hysterectomy patients from the NSQIP dataset over 14 years were used to develop models with a training set of 2925 patients and a validation set of 731 patients. Our models revealed the top postoperative predictors of residual disease were the initial presence of gross abdominal disease on the diaphragm, disease located on the bowel mesentery, located on the bowel serosa, and disease located within the adjacent pelvis prior to resection. There were no statistically significant differences in performances of the top three models. Extreme gradient Boosting, Random Forest, and Logistic Regression models had comparable AUC ROC (0.90) and accuracy metrics (87–88%). Using these models, physicians can identify gynecologic cancer patients post-hysterectomy that may benefit from additional treatment. For patients at high risk for disease recurrence despite adequate surgical intervention, machine learning models may lay the basis for potential prospective trials with prophylactic/adjuvant therapy for non-clinically evident residual disease, particularly in under-resourced settings.

Impact of Reconstruction Route on Postoperative Morbidity After Esophagectomy: Analysis of Esophagectomies in the Japanese National Clinical Database

BACKGROUND

Esophagectomy followed by gastric conduit reconstruction is a standard surgical procedure for esophageal cancer. However, there is no evidence of the superiority or inferiority of the posterior mediastinal (PM) versus the retrosternal (RS) reconstruction route with regard to short-term outcomes after esophagectomy. We aimed to elucidate whether the reconstruction route can affect the short-term outcomes after esophagectomy followed by gastric conduit reconstruction.

METHODS

We reviewed the clinical data of patients who underwent esophagectomy between 2016 and 2018 from the Japanese National Clinical Database. This study included 9786 patients who underwent gastric conduit reconstruction through the PM or RS route with cervical anastomosis.

RESULTS

Of the 9786 patients analyzed, 3478 and 6308 underwent gastric conduit reconstruction thorough the PM and RS routes, respectively. The incidence of anastomotic leak and surgical site infection (SSI) was significantly lower in the PM group than in the RS group (11.7% vs 13.8%, P = .005 and 8.4% vs 14.9%, P < .001, respectively), while the incidence of pneumonia was higher in the PM group (13.7% vs 12.2%, P = .040). Generalized estimating equation logistic regression analysis revealed a higher risk of anastomotic leak and SSI (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.15-1.51; P < .001 and OR, 2.06; 95% CI, 1.78-2.38; P < .001, respectively) and a lower risk of pneumonia (OR, 0.86; 95% CI, 0.75-0.98; P = .028) in the RS group than in the PM group.

CONCLUSION

The findings of this study will help surgeons to design the reconstruction route following esophagectomy.

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.

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.