Optimal extent of lymph node dissection for high-risk gastric cancer stratified by a national clinical database risk calculator.

BACKGROUND: For patients with gastric cancer, a well-balanced treatment that considers both oncological aspects and surgical risk is demanded. This study aimed to explore the optimal extent of lymph node dissection (LND) for patients with gastric cancer according to surgical risk, stratified by the risk calculator system produced by the Japan National Clinical Database (NCD). PATIENTS AND METHODS: We retrospectively evaluated 187 patients who underwent radical gastrectomy for gastric cancer. Using the median predicted anastomotic leak rate obtained by the NCD risk calculator as the cutoff value, we classified 97 and 90 patients as having high and low risks, respectively. RESULTS: In low-risk patients, although limited LND reduced the postoperative intraabdominal infectious complications (IAIC), multivariate analysis revealed standard LND as an independent prognostic factor that improved Relapse-free survival (RFS). In high-risk patients, the rates of postoperative IAIC and RFS were similar between standard and limited LND. Pancreatic fistula was not observed in the limited dissection group. CONCLUSION: Limited LND might be the optimal treatment strategy for patients with gastric cancer with high surgical risk.

Impact of the novel coronavirus infection on pediatric surgery: an analysis of data from the National Clinical Database.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic limited the delivery of medical resources. Although surgeries are triaged according to disease severity and urgency, a delay in diagnosis and surgery can be detrimental. We conducted this study to analyze data on the impact of the COVID-19 pandemic on pediatric surgery for different diseases or disorders. METHODS: We compiled and compared data on pediatric surgical cases from 2018 to 2020, using the National Clinical Database. The number of diseases, severity, complication rates, mortality rates by disease/disorder, and the COVID-19 pandemic areas were analyzed. RESULTS: The total number of cases of pediatric surgery in 2018, 2019, and 2020 was 50,026, 49,794, and 45,621, respectively, reflecting an 8.8% decrease in 2020 from 2018 and an 8.4% decrease in 2020 from 2019. A decrease was observed when the number of patients with COVID-19 was high and was greater in areas with a low infection rate. There was a marked decrease in the number of inguinal hernia cases. The number of emergency room visits and emergency surgeries decreased, but their relative proportions increased. CONCLUSIONS: The COVID-19 pandemic decreased the number of pediatric surgeries, reflecting the limitations of scheduled surgeries and infection control measures.

Impact of the coronavirus disease 2019 pandemic on 20 representative surgical procedures in Japan based on the National Clinical Database: annual surveillance of 2021 by the Japan Surgical Society.

PURPOSE: The volume of surgical services has significantly reduced globally due to the coronavirus disease 2019 (COVID-19) pandemic. This study evaluated the level of recovery in terms of the number of operations performed in Japan in 2021, based on nationwide periodic surveillance. METHODS: Information on the weekly and annual volumes of 20 representative procedures in 6 surgical subspecialties in 2021 was extracted from the National Clinical Database. Statistical data for 2018 and 2019 (pre-pandemic era) were compared with those for 2020. Data on waves of infection, peak period, and high-prevalence areas (13 of 47 prefectures) were analyzed individually. RESULTS: The volumes of the 10 procedures, including gastrectomy, hepatectomy, valve replacement and valve plasty, coronary artery bypass grafting, infrarenal abdominal aorta replacement, ventricular septal defect closure, lung lobectomy, inguinal hernia repair (age < 16 years old), and appendectomy (age < 16 years old), did not reach 95% of that in the pre-pandemic era. The most striking decline in the surgical volume of these 10 procedures was observed during the peak period of wave 5 in high-prevalence areas. CONCLUSION: This near-complete enumeration survey identified the polarization of 20 representative procedures in terms of resumption of surgical service after the pandemic.

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.

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.

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.

Influence of patient position in thoracoscopic esophagectomy on postoperative pneumonia: a comparative analysis from the National Clinical Database in Japan.

BACKGROUND: Two prominent patient positions during thoracoscopic esophagectomy are the left lateral decubitus position (LP) and the prone position (PP). However, whether the patient position during thoracoscopic esophagectomy influences short-term outcomes, especially postoperative pneumonia, remains unclear. We aimed to elucidate the impact of patient position on the occurrence of postoperative pneumonia. METHODS: We analyzed 9850 patients who underwent oncologic thoracoscopic esophagectomies between 2016 and 2019 from the National Clinical Database. We compared the short-term outcomes between the LP and PP groups, and the primary outcome measure was the incidence of postoperative pneumonia. RESULTS: This study included 2637 (26.8%) and 7213 (73.2%) patients in the LP and the PP groups, respectively. The baseline characteristics of the two groups were well-balanced. Compared with the LP group, the PP group had a longer operative time and less blood loss. There were no significant differences in the incidences of postoperative pneumonia, recurrent laryngeal nerve palsy, anastomotic leakage, severe complications, and reoperation between the groups. Meanwhile, prolonged ventilation and surgery-related mortality occurred more frequently in the LP than in the PP group (P < 0.001 and 0.046, respectively). After multivariable adjustment, the patient position did not significantly influence the incidence of postoperative pneumonia (odds ratio 0.91, 95% confidence interval 0.80-1.04). CONCLUSIONS: Although prolonged ventilation and surgery-related mortality occurred more frequently in the LP group than in the PP group, the patient position did not significantly influence the occurrence of postoperative pneumonia.

The impact of COVID-19 on surgical procedures in Japan: analysis of data from the National Clinical Database.

BACKGROUND AND PURPOSE: The spread of COVID-19 has restricted the delivery of standard medical care to surgical patients dramatically. Surgical triage is performed by considering the type of disease, its severity, the urgency for surgery, and the condition of the patient, in addition to the scale of infectious outbreaks in the region. The purpose of this study was to evaluate the impact of the COVID-19 pandemic on the number of surgical procedures performed and whether the effects were more prominent during certain periods of widespread infection and in the affected regions. METHODS: We selected 20 of the most common procedures from each surgical field and compared the weekly numbers of each operation performed in 2020 with the respective numbers in 2018 and 2019, as recorded in the National Clinical Database (NCD). The surgical status during the COVID-19 pandemic as well as the relationship between surgical volume and the degree of regional infection were analyzed extensively. RESULTS: The rate of decline in surgery was at most 10-15%. Although the numbers of most oncological and cardiovascular procedures decreased in 2020, there was no significant change in the numbers of pancreaticoduodenectomy and aortic replacement procedures performed in the same period. CONCLUSION: The numbers of most surgical procedures decreased in 2020 as a result of the COVID-19 pandemic; however, the precise impact of surgical triage on decrease in detection of disease warrants further investigation.

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.

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

BACKGROUND: Postoperative intra-abdominal infectious complication (PIIC) after gastrectomy for gastric cancer worsens in-hospital death or long-term survival. However, the methodology for PIIC preoperative risk assessment remains unestablished. We aimed to develop a preoperative risk model for postgastrectomy PIIC. METHODS: We collected 183,936 patients' data on distal or total gastrectomy performed in 2013-2016 for gastric cancer from the Japanese National Clinical Database and divided into development (2013-2015; n = 140,558) and validation (2016; n = 43,378) cohort. The primary outcome was the incidence of PIIC. The risk model for PIIC was developed using 18 preoperative factors: age, sex, body mass index, activities of daily living, 12 comorbidity types, gastric cancer stage, and surgical procedure in the development cohort. Secondarily, we developed another model based on the new scoring system for clinical use using selected factors. RESULTS: The overall incidence of PIIC was 4.7%, including 2.6%, 1.7%, and 1.3% in anastomotic leakage, pancreatic fistula, and intra-abdominal abscess, respectively. Among the 18 preoperative factors, male [odds ratio, (OR) 1.92], obesity (OR, 1.52-1.96), peripheral vascular disease (OR, 1.55), steroid use (OR, 1.83), and total gastrectomy (OR, 1.89) strongly correlated with PIIC incidence. The entire model using the 18 factors had good discrimination and calibration in the validation cohort. We selected eight relevant factors to create a simple scoring system, using which we categorized the patients into three risk groups, which showed good calibration. CONCLUSION: Using nationwide clinical practice data, we created a preoperative risk model for postgastrectomy PIIC for gastric cancer.

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.

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.

Introducing laparoscopic total gastrectomy for gastric cancer in general practice: a retrospective cohort study based on a nationwide registry database in Japan.

BACKGROUND: Although laparoscopic total gastrectomy (LTG) is considered a technically demanding procedure with safety issues, it has been performed in several hospitals in Japan. Data from a nationwide web-based data entry system for surgical procedures (NCD) that started enrollment in 2011 are now available for analysis. METHODS: A retrospective cohort study was conducted using data from 32,144 patients who underwent total gastrectomy and were registered in the NCD database between January 2012 and December 2013. Mortality and morbidities were compared between patients who received LTG and those who underwent open total gastrectomy (OTG) in the propensity score-matched Stage I cohort and Stage II-IV cohort. RESULTS: There was no significant difference in mortality rate between LTG and OTG in both cohorts. Operating time was significantly longer in LTG while the blood loss was smaller. In the Stage I cohort, LTG, performed in 33.6% of the patients, was associated with significantly shorter hospital stay but significantly higher incidence of readmission, reoperation, and anastomotic leakage (5.4% vs. 3.6%, p < 0.01). In the Stage II-IV cohort, LTG was performed in only 8.8% of the patients and was associated with significantly higher incidence of leakage (5.7% vs. 3.6%, p < 0.02) although the hospital stay was shorter (15 days vs. 17 days, p < 0.001). CONCLUSION: LTG was more discreetly introduced than distal gastrectomy, but remained a technically demanding procedure as of 2013. This procedure should be performed only among the well-trained and informed laparoscopic team.

Validity of additional surgical resection by comparing the operative risk with the stratified lymph node metastatic risk in patients with early gastric cancer after endoscopic submucosal dissection.

BACKGROUND: Treatment guidelines for early gastric cancer (EGC) recommend additional gastrectomy for lesions which do not achieve curative resection after ESD, due to the potential risk of lymph node metastasis (LNM). However, many cases are found to have no LNMs, and additional gastrectomy itself can be a considerable risk especially in elderly patients. METHODS: We retrospectively stratified the risk of LNM according to the total number of four LNM risk factors (RFs) that resulted in non-curative resection for ESD in 861 EGC patients who underwent gastrectomy. Next, we compared this stratification risk to the surgical risk based on the National Clinical Database (NCD) risk calculator in 58 patients who underwent additional gastrectomy. RESULTS: As the total number of LNM RFs increased, the frequency of LNM also increased significantly (0/1RF 0.76%, 2RFs 15.08%, 3RFs 33.87%, 4RFs 50.00%; p < 0.01). The estimated frequency of LNM was found to be lower than the predicted value of in-hospital mortality rate based on the NCD risk calculator in 25.0% of 0/1RF patients. CONCLUSION: These findings indicate, at least, that we should discuss the indication of additional gastrectomy individually for each patient from both perspectives of LNM and surgical risks.

Evaluating the quality of data from the Japanese National Clinical Database 2011 via a comparison with regional government report data and medical charts.

PURPOSE: The aim of this study was to examine the quality of data from the National Clinical Database (NCD) via a comparison with regional government report data and medical charts. METHODS: A total of 1,165,790 surgical cases from 3007 hospitals were registered in the NCD in 2011. To evaluate the NCD's data coverage, we retrieved regional government report data for specified lung and esophageal surgeries and compared the number with registered cases in the NCD for corresponding procedures. We also randomly selected 21 sites for on-site data verification of eight demographic and surgical data components to assess the accuracy of data entry. RESULTS: The numbers of patients registered in the NCD and regional government report were 46,143 and 48,716, respectively, for lung surgeries and 7494 and 8399, respectively, for esophageal surgeries, leading to estimated coverages of 94.7% for lung surgeries and 89.2% for esophageal surgeries. According to on-site verification of 609 cases at 18 sites, the overall agreement between the NCD data components and medical charts was 97.8%. CONCLUSION: Approximately, 90-95% of the specified lung surgeries and esophageal surgeries performed in Japan were registered in the NCD in 2011. The NCD data were accurate relative to medical charts.

Initial verification of data from a clinical database of gastroenterological surgery in Japan.

PURPOSES: To evaluate the reliability of data collected from the gastroenterological section of the National Clinical Database of Japan (NCD), which began registrations in 2011 with ten surgical subspecialty societies. METHODS: During 2014 and 2015, 1,136,700 cases involving 115 procedures at 4374 hospitals were registered in the gastroenterological surgery section of the NCD. After a test audit using the 2014 data, 17 hospitals were selected for the first audit and data verification for 2015. The data accuracy of patient demographics, surgical outcomes, and processes was assessed using 45 items from the cases registered, in comparison with the medical records. RESULTS: In the first audit of the 2015 data, case registration accuracy verification involved 338 patients (99.4% of the extracted cases). The data accuracy with the maximum postoperative variables was > 95%. Accuracy of the mortality and status 30 days after the surgery was high (> 99%) with a sensitivity of 1.00 and a specificity of 1.00. Among the six complications studied, the recorded cases had high specificity but lower sensitivity (0.70-0.89). CONCLUSIONS: We verified the data from the gastroenterological section of the NCD and found high accuracy of data entry.

Higher incidence of pancreatic fistula in laparoscopic gastrectomy. Real-world evidence from a nationwide prospective cohort study.

BACKGROUND: Laparoscopic distal gastrectomy (LDG) is becoming the standard procedure for gastric cancer. However, supporting evidence thus far has been derived primarily from randomized control trials conducted by centers of excellence. In the present study we used the National Clinical Database (NCD) in Japan to prospectively accumulate data from diverse types of hospitals and examine whether LDG is a safe and valid standard procedure. METHODS: From the NCD, 169 institutions were selected to form a cohort that was considered to be representative of Japan. From August 2014 to July 2015, 5288 patients who underwent LDG were registered prospectively, and clinical data were acquired through the NCD. To compare surgical outcomes between open distal gastrectomy (ODG) and LDG, we adjusted for confounding factors using propensity score matching, ultimately retrieving data from 1067 patients in each group. RESULTS: There were no significant differences in the number of in-hospital deaths in the ODG and LDG groups (3/1067 vs. 6/1067; P = 0.51) or in the number of reoperations (20/1067 vs. 29/1067; P = 0.19). However, the length of hospital stay was significantly shorter in the LDG. Although wound infection and dehiscence were more common in the ODG group, LDG was more often associated with grade B or higher pancreatic fistulas. CONCLUSION: The safety and minimal invasiveness of LDG were confirmed in the present Japanese nationwide survey. However, care must be taken to prevent the formation of pancreatic fistulas with LDG, and further improvements in surgical quality are warranted in this regard.

Morbidity and mortality from a propensity score-matched, prospective cohort study of laparoscopic versus open total gastrectomy for gastric cancer: data from a nationwide web-based database.

BACKGROUND: Controversy persists regarding the technical feasibility of laparoscopic total gastrectomy (LTG), and to our knowledge, no prospective study with a sample size sufficient to investigate its safety has been reported. We aimed to compare the postoperative morbidity and mortality rates in patients undergoing LTG and open total gastrectomy (OTG) for gastric cancer in prospectively enrolled cohort using nationwide web-based registry. METHODS: From August 2014 to July 2015, consecutive patients undergoing LTG or OTG (925 and 1569 patients, respectively) at the participating institutions were enrolled prospectively into the National Clinical Database registration system. We constructed propensity score (PS) models separately in four facility yearly case-volume groups, and evaluated the postoperative morbidity and mortality in PS-matched 1024 patients undergoing LTG or OTG. RESULTS: The incidence of overall morbidity were 84 (16.4%) in the OTG and 54 (10.3%) in the LTG groups (p = 0.01).The incidence of anastomotic leakage and pancreatic fistula grade B or above were not significantly different between the two groups (LTG 5.3% vs. OTG 6.1%, p = 0.59, LTG 2.7% vs. OTG 3.7%, p = 0.38, respectively). There were also no significant differences in the 30-day and in-hospital mortality rates between the two groups (LTG 0.2% vs. OTG 0.4%, p = 0.56; LTG 0.4% vs. OTG 0.4%, p = 1.00, respectively). CONCLUSION: The results from our nationally representative data analysis showed that LTG could be a safe procedure to treat gastric cancer compared to OTG. The indication for LTG should be considered carefully in a clinical setting.

Development and external validation of preoperative risk models for operative morbidities after total gastrectomy using a Japanese web-based nationwide registry.

BACKGROUND: Total gastrectomy is a relatively difficult and invasive procedure among gastrointestinal surgeries, and major morbidities following total gastrectomy can be serious and fatal. This study aimed to develop and validate preoperative risk models of morbidities associated with total gastrectomy using a Japanese web-based nationwide registry. METHODS: The national clinical database was used to retrieve the records of 39,253 patients who underwent total gastrectomy in 1,841 hospitals between January 1, 2011 and December 31, 2012. RESULTS: Mean patient age was 69.1 years, and 73.8% of the patients were male. The overall morbidity rate was 21.5%, which included 8.1% with surgical site infection (SSI), 4.5% with anastomotic leak, 5.0% with pancreatic fistula, 3.7% with pneumonia, 1.9% with prolonged ventilation, and 1.2% with renal failure. Sex, splenectomy, and Brinkman index were selected as common risk factors for SSI, anastomotic leak, and pancreatic fistula. Pancreatectomy was the most significant preoperative risk factor in the risk model of SSI and pancreatic fistula. Need of assistance with activities of daily living, chronic obstructive pulmonary disease, previous cerebrovascular disease, American Society of Anesthesiologists score class 3 and over, presence of esophageal cancer, and body mass index more than 25 were selected as common risk factors for pneumonia, prolonged ventilation over 48 h, and renal failure. CONCLUSIONS: We have created the first reported risk models of morbidities associated with total gastrectomy, using a Japanese nationwide database. The risk models developed in this study may be useful to preoperatively predict operative morbidities in patients undergoing total gastrectomy.

Modeling preoperative risk factors for potentially lethal morbidities using a nationwide Japanese web-based database of patients undergoing distal gastrectomy for gastric cancer.

BACKGROUND: Most risk models for mortality and morbidity after distal gastrectomy have been created based on relatively small retrospective studies, and a model originating from nationwide database has been lacking. This study aimed to identify preoperative risk factors that predict the postoperative morbidities closely associated with mortality in gastric cancer patients undergoing distal gastrectomy, using data from the National Clinical Database (NCD), a nationwide web-based database in Japan. METHODS: We analyzed records from the NCD for 65,906 patients who underwent distal gastrectomy in 1,986 hospitals during 2011 and 2012. Using 80 % of these patients, we identified independent preoperative predictors for morbidities closely related with mortality. These risk factors were then validated using the remaining 20 % of patients from 2011 to 2012 and the further 35,575 records from 2013. RESULTS: Operative mortality was 1.07 % and overall morbidity was 14.2 % for the development data set. We selected eight morbidities that were closely associated with postoperative mortality, and then identified between 13 and 25 independent preoperative risk factors for each of the eight morbidities. Of these, old age, female gender, and poor ADL were the factors most frequently associated with the morbidities. The C-indices for each morbidity from the 2011 to 2012 validation data set were favorable as follows: unplanned intubation (0.797), pneumonia (0.784), systemic sepsis (0.748), renal failure (0.832), cardiac events (0.728), large blood transfusions (0.700), central nervous system (CNS) events (0.779), and anastomotic leakage (0.658). Similar C-indices were obtained for each mortality using the 2013 validation data set. CONCLUSIONS: In this study, we successfully constructed an acceptable risk model using preoperative risk factors to predict eight postoperative morbidities highly associated with mortality in gastric cancer patients. This risk model could help to tailor perioperative management and improve clinical outcomes for patients who undergo distal gastrectomy.