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

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.

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.

Saccular and Fusiform Abdominal Aortic Aneurysms Treated With Endovascular Repair Differ in Presentation and Treatment Threshold: Analyses Using a National Clinical Database in Japan

BACKGROUND

Saccular abdominal aortic aneurysms (AAAs) are considered to be at higher risk of rupture than fusiform AAAs, but not much is known about the extent of this risk. Therefore, this study aimed to compare the rupture presentation between fusiform and saccular AAAs.

METHODS AND RESULTS

This is a retrospective cohort study on 27 290 patients who underwent primary endovascular repair for a degenerative AAA between 2016 and 2019, and who were registered in the National Clinical Database in Japan. At operation for nonruptured case, the aneurysm diameter was significantly smaller in saccular AAAs than in fusiform AAAs (median, 44.0 versus 51.0 mm; P<0.001). Similarly, aneurysm diameter at rupture was significantly smaller in saccular AAAs than in fusiform AAAs (median, 55.6 versus 68.0 mm; P<0.001). The likelihood of repair for rupture was significantly higher in saccular AAAs than in fusiform AAAs in the 40- to 54-mm diameter range, in which saccular morphology was found to be an independent risk factor for rupture against fusiform morphology by adjusting for sex and aneurysm diameter (odds ratio, 2.54 [95% CI, 1.75-3.69]). In addition, receiver-operating characteristic curve analysis revealed that the cutoff diameter to predict rupture was smaller in saccular AAAs than in fusiform AAAs (50.5 and 59.5 mm, respectively) based on the Youden index.

CONCLUSIONS

Saccular AAAs presented at smaller diameters than fusiform AAAs in patients with ruptured AAAs treated with endovascular aortic repair, which supports the idea that saccular AAAs should be treated at smaller diameters.

Prognostic factors after open and endovascular repair for infected native aneurysms of the abdominal aorta and common iliac artery

OBJECTIVE

Infected native aneurysms (INAs) of the abdominal aorta and iliac arteries are uncommon, but potentially fatal. Endovascular aneurysm repair (EVAR) has recently been introduced as a durable treatment option, with outcomes comparable to those yielded by conventional open repair. However, owing to the rarity of the disease, the strengths and limitations of each treatment remain uncertain. The present study aimed to separately assess post-open repair and post-EVAR outcomes and to clarify factors affecting the short-term and late prognosis after each treatment.

METHODS

Using a nationwide clinical registry, we investigated 600 patients treated with open repair and 226 patients treated with EVAR for INAs of the abdominal aorta and/or common iliac artery. The relationships between preoperative or operative factors and postoperative outcomes, including 90-day and 3-year mortality and persistent or recurrent aneurysm-related infection, were examined.

RESULTS

Prosthetic grafts were used in >90% of patients treated with open repair, and in situ and extra-anatomic arterial reconstruction was performed in 539 and 57 patients, respectively. Preoperative anemia and imaging findings suggestive of aneurysm-enteric fistula were independently associated with poor outcomes in terms of both 3-year mortality (hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.01-2.62; P = .046, and HR, 2.24; 95% CI, 1.12-4.46; P = .022, respectively) and persistent or recurrent infection (odds ratio [OR], 2.16; 95% CI, 1.04-4.49; P = .039, and OR, 4.96; 95% CI, 1.81-13.55; P = .002, respectively) after open repair, whereas omental wrapping or packing and antibiotic impregnation of the prosthetic graft for in situ reconstruction contributed to improved 3-year survival (HR, 0.60; 95% CI, 0.39-0.92; P = .019, and HR, 0.53; 95% CI, 0.32-0.88; P = .014, respectively). Among patients treated with EVAR, abscess formation adjacent to the aneurysm was significantly associated with the occurrence of persistent or recurrent infection (OR, 2.24; 95% CI, 1.06-4.72; P = .034), whereas an elevated preoperative white blood cell count was predictive of 3-year mortality (HR, 1.77; 95% CI, 1.00-3.13; P = .048).

CONCLUSIONS

Profiles of prognostic factors differed between open repair and EVAR in the treatment of INAs of the abdominal aorta and common iliac artery. Open repair may be more suitable than EVAR for patients with concurrent abscess formation.

Surgical Repair of Abdominal Aorto-Iliac Prosthetic Graft Infections: A Nationwide Japanese Cohort Study

OBJECTIVE

Prosthetic graft infection (PGI) after open abdominal aortic and iliac artery reconstruction is life threatening. However, because it is rare and frequently difficult to diagnose, robust evidence on its treatment and optimal management strategies are lacking. This study aimed to clarify the clinical characteristics and surgical treatment outcomes of this condition and to identify pre-operative and operative factors affecting its prognosis.

METHODS

This was a nationwide cohort study. Using a nationwide clinical registry system, patients who were treated surgically for PGI after open abdominal aortic and iliac artery reconstruction between 2011 and 2017 were investigated, and their profiles and clinical courses were analysed. The relationships between the pre-operative and operative factors and the post-operative outcomes, including death and persistent or recurrent graft related infection, were evaluated.

RESULTS

The study included 213 patients. The median duration between the index arterial reconstruction and surgical treatment for PGI was 644 days. Fistula development to the gastrointestinal tract was confirmed during surgery in 53.1% of patients. The cumulative overall survival rates at 30 and 90 days, one, three, and five years were 87.3%, 74.8%, 62.2%, 54.5%, and 48.1%, respectively. Pre-operative shock was the only factor independently associated with 90 day and three year death. Short term and late mortality rates, as well as the rate of persistent or recurrent graft related infection, did not differ significantly between patients treated with total removal of the infected graft and those treated with partial removal of the graft.

CONCLUSION

Surgery for PGI after open reconstruction of the abdominal aorta and iliac arteries is complex, and the post-operative mortality rate remains high. Partial removal of the infected graft may be an alternative in selected patients with limited extent of infection.

Surgical Treatment for Popliteal Artery Entrapment Syndrome in Japan: a Retrospective, Multicentre Study Using a National Clinical Registry

OBJECTIVE

Surgical treatment is an established method for popliteal artery entrapment syndrome (PAES), which, however, mainly derives from single centre experiences where PAES cases are centralised and treated periodically. This study evaluated clinical outcomes of surgical treatment for PAES in a clinical setting where PAES cases were not centralised.

METHODS

Multicentre, retrospective cohort study using a national clinical registry. From a Japanese nationwide clinical registry, data for patients who underwent surgical treatment for PAES between 2013 and 2018, including 58 limbs from 41 institutes, were retrieved and evaluated. Patency was analysed using Kaplan-Meier curves.

RESULTS

The mean patient age was 36 ± 19 years, 78% were male, and the incidence of PAES was 0.24 limbs/centre/year, reflecting a clinical setting where PAES cases are not centralised. The most frequent arterial symptom was intermittent claudication (90%). Computed tomography was performed in 57 limbs (98%) for the diagnosis, however active manoeuvres such as dorsiflexion and plantarflexion during the examination was performed in only 13 limbs (22%), and occlusion of the popliteal artery was present in 38 limbs (66%) at diagnosis. Regarding surgical treatment, myotomy alone was performed in only seven limbs (12%), and other limbs were revascularised. Mean follow up was 26 ± 20 months, and surgical treatment was effective as it relieved symptoms in > 96% of limbs, with five year primary and secondary patency of the surgical treatment for PAES of 72% and 93%, respectively.

CONCLUSION

Results of surgical treatment were acceptable even in a clinical setting where PAES cases were not centralised. However, a low incidence of active manoeuvres performed during the examination and a high incidence of occlusion at diagnosis suggests there may be delayed or underdiagnosis of PAES in Japan, and increased awareness for PAES is warranted.

Outcomes of Surgery for Endograft Infection in the Abdominal Aorta and Iliac Artery: A Nationwide Cohort Study

OBJECTIVE

This study aimed to clarify the clinical features, postoperative outcomes, and prognostic factors in patients with endograft infection in the abdominal aorta and iliac artery.

SUMMARY BACKGROUND DATA

Endograft infection in the abdominal aorta and iliac artery is a potentially fatal condition. However, due to its rarity, clinical characteristics and optimal treatment strategy remain to be established.

METHODS

In this nationwide retrospective cohort study, we investigated 112 patients who underwent surgical treatment for endograft infection in the abdominal aorta and/or iliac artery between 2011 and 2017 using a Japanese clinical registry. We examined the relationships between the preoperative and operative factors and the outcomes after surgery including persistent or recurrent infection related to the endograft and 90-day and 3-year mortality.

RESULTS

The median period between the index endograft placement and surgery for infection was 369.5 days. Persistent or recurrent endograft-related infection occurred in 34 patients (30.4%). The cumulative overall survival rates at 30 days, 90 days, 1 year, 3 years, and 5 years were 90.2%, 76.5%, 66.7%, 50.9%, and 31.5%, respectively. Partial removal or total preservation of the infected endograft was independently associated with short-term and late mortality. Preoperative anemia and imaging findings suggestive of fistula development to the gastrointestinal tract also showed an independent association with late mortality.

CONCLUSIONS

Surgical intervention for endograft infection in the abdominal aorta and iliac artery was associated with a high risk of postoperative morbidity and mortality. Total removal of the infected endograft should be attempted because partial removal or total preservation can lead to a poor prognosis.

Volume- and quality-controlled certification system promotes centralization of complex hepato-pancreatic-biliary surgery

BACKGROUND

Centralization of complex surgeries has made little progress when it only considers the minimum number of surgical procedures. We aim to assess the impact of certification system of Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS) on centralization and surgical quality of advanced hepato-pancreatic-biliary (HPB) surgery.

METHODS

The National Clinical Database was used to review 20 111 patients who underwent pancreatoduodenectomy (PD) and 9666 who underwent advanced hepatectomy defined as hepatectomy of more than one section during 2019 and 2020. JSHPBS certifies hospitals based on the annual number of advanced HPB surgeries and the surgical quality. Minimum numbers of surgeries for board-certified A and B institutions are 50 and 30, respectively. Short-term outcomes were compared among institutions.

RESULTS

In 2020, 69.4% (7007/10090) and 72.9% (3433/4710) of patients underwent PD and advanced hepatectomy at board-certified institutions. In-hospital mortality rates after PD was 0.9% at certified A institutions, 1.4% at B institutions, and 2.7% at non-certified institutions (p < .001). The odds ratio (OR) of risk-adjusted mortality after PD compared with non-certified institutions was 0.39 (confidence interval [CI]: 0.30-0.50, p < .001) at certified A institutions, and 0.54 at certified B institutions (CI: 0.40-0.73, p < .001). In-hospital mortality rates after advanced hepatectomy was 1.7% at certified A institutions, 2.3% at B institutions, and 3.2% at non-certified institutions (p < .001). The OR of risk-adjusted mortality after advanced hepatectomy compared with non-certified institutions was 0.57 at certified A institutions (CI: 0.41-0.78, p < .001).

CONCLUSION

The volume- and quality-controlled certification system of JSHBPS reduces surgical mortality after advanced HPB surgeries.

Effects of the COVID ‐19 pandemic on gastroenterological surgeries in 2020: A study using the National Clinical Database of Japan

Aim

This study aimed to investigate the effect of the coronavirus disease pandemic on the number of surgeries for gastroenterological cancer cases in Japan.

Methods

The data recorded in the National Clinical Database of Japan between 2018 and 2020 were utilized for this study. Five specific surgeries for primary cancers and surgery for acute diffuse peritonitis were considered the primary endpoints. We divided the study period into the prepandemic and postpandemic (after April 2020) periods and examined the number of surgeries in relation to clinical factors.

Results

Overall, 228 860 surgeries were analyzed. Among the five primary cancer surgeries, the number of distal gastrectomies for gastric cancer decreased the most (to 81.0% of the monthly number in the prepandemic period), followed by that of low anterior resections for rectal cancer (91.4%). In contrast, the number of pancreaticoduodenectomies for pancreatic cancer increased by 7.1%, while that of surgeries for peritonitis remained stable. This trend was observed nationwide. We also noted a marked reduction in the number of distal gastrectomy (to 72.5%), low anterior resection (84.0%), and esophagectomy (88.8%) procedures for T1 tumors. The noncurative resection rate and mortalities were low despite the increased proportion of T4 tumors and older patients.

Conclusion

A marked reduction in surgeries for gastric and rectal cancers with early T factors may reflect prioritization of surgeries and reduction in cancer screenings. Although the quality of the surgery was maintained in terms of reduced mortalities and morbidities, the long-term effects of this pandemic should be monitored.

Prediction Models for Two Year Overall Survival and Amputation Free Survival After Revascularisation for Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to create prediction models for two year overall survival (OS) and amputation free survival (AFS) after revascularisation in patients with chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective analysis of prospectively collected multicentre registry data (JAPAN Critical Limb Ischaemia Database; JCLIMB). Data from 3 505 unique patients with CLTI who had undergone revascularisation from 2013 to 2017 were extracted from the JCLIMB for the analysis. The cohort was randomly divided into development (2 861 patients) and validation cohorts (644 patients). In the development cohort, multivariable risk models were constructed to predict two year OS and AFS using Cox proportional hazard regression analysis. These models were applied to the validation cohort and their performances were evaluated using Harrell's C index and calibration plots.

RESULTS

Kaplan-Meier estimates of two year OS and AFS post-revascularisation in the whole cohort were 69% and 62%, respectively. Strong predictors for OS consisted of age, activity, malignant neoplasm, chronic kidney disease (CKD), congestive heart failure (CHF), geriatric nutritional risk index (GNRI), and sex. Strong predictors for AFS included age, activity, malignant neoplasm, CKD, CHF, GNRI, body temperature, white blood cells, urgent revascularisation procedure, and sex. Prediction models for two year OS and AFS showed good discrimination with Harrell's C indexes of 0.73 (95% confidence interval [CI] 0.69 - 0.77) and 0.72 (95% CI 0.68 - 0.76), respectively CONCLUSION: Prediction models for two year OS and AFS post-revascularisation in patients with CLTI were created. They can assist in determining treatment strategies and serve as risk adjustment modalities for quality benchmarking for revascularisation in patients with CLTI at each facility.

Day of surgery and mortality after pancreatoduodenectomy: A retrospective analysis of 29 270 surgical cases of pancreatic head cancer from Japan

BACKGROUND/PURPOSE

The day of the week can impact medical treatment outcomes; however, few large-scale, disease-specific studies have focused on the association between the day of the week and mortality in patients after pancreatoduodenectomy for pancreatic head cancer.

METHODS

Data were obtained from the National Clinical Database. Twenty-two clinical variables were adopted for hierarchal logistic regression modeling to determine adjusted odds ratios (ORs) for surgical mortality after elective pancreatoduodenectomy.

RESULTS

The 30-day mortality and surgical mortality rates were 1.0% and 1.7%, respectively (n = 29 720). Surgeries were performed the least on Fridays (13.4%) compared with other weekdays. Crude rates of severe postoperative complications (mean, 14.1%; range, 13.5%-14.8%) and pancreatic fistulas (mean, 10.0%; range, 9.6%-10.3%) remained stable throughout the week. Unadjusted/adjusted ORs did not significantly differ between Friday and Monday (0.868, 95% CI: 0.636-1.173, P = .365, and 0.928, 95% CI: 0.668-1.287, P = .653, respectively), and results were similar for the remaining weekdays. Nineteen independent factors were associated with surgical mortality.

CONCLUSIONS

The rate of perioperative mortality for elective pancreatoduodenectomy is low in Japan, with no evidence of disparities in surgical mortality rates between weekdays.

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.

Correlation between surgical mortality for perforated peritonitis and days of the week for operations: A retrospective study using the Japanese National Clinical Database

BACKGROUND

The association between weekend interventions and poor outcomes is termed the "weekend effect." This retrospective study investigated whether the weekend effect exists in the surgical treatment of acute diffuse peritonitis due to gastrointestinal perforation.

METHODS

Patients (n = 16,209) who underwent operation for acute diffuse peritonitis during 2016-2017 were included and grouped depending on the perforation site. Using 23 variables, we performed hierarchical logistic regression analysis and calculated odds ratios for surgical mortality.

RESULTS

Surgical mortality rates were 8.8%, 15.0%, and 14.1% for patients with gastroduodenal, small bowel, and large bowel perforations, respectively. Unadjusted odds ratios for surgical mortality differed significantly on Wednesdays only for patients with large bowel perforation (odds ratio: 0.772, 95% confidence interval: 0.613-0.972, P = 0.03). However, there was no significant difference in adjusted odds ratios.

CONCLUSION

The quality of emergency surgical treatment is uniform in Japan throughout the week in terms of mortality.

Is radiological psoas muscle area measurement a predictor of postoperative complications after rectal resection for rectal cancer? A retrospective study

PURPOSE

Previous studies have reported that sarcopenia increases the risk of postoperative complications following colorectal resection. This retrospective study assessed the postoperative complications of rectal resection associated with sarcopenia.

METHODS

We retrospectively analyzed 262 patients who underwent curative low anterior resection for primary rectal cancer from January 2008 to May 2020 at our institution. The patients were divided into a sarcopenia group (normalized total psoas muscle area < 6.36 cm²/m² in males and < 3.92 cm²/m² in females; N = 49) and a non-sarcopenia group (N = 213).

RESULTS

The overall rate of postoperative complications within 30 days of surgery was higher in the sarcopenia group than in the non-sarcopenia group (46.9 vs. 29.6%; P = 0.028). The rate of postoperative remote infections was higher in the sarcopenia group than in the non-sarcopenia group (12.2 vs. 2.8%; P = 0.012). Sarcopenia was found to be a predictor of remote infection by a multivariate analysis (odds ratio, 4.08; 95% confidence interval, 1.12-14.80; P = 0.033).

CONCLUSION

Sarcopenia diagnosed using the psoas muscle index was found to be an independent predictive factor for postoperative remote infection after curative low anterior resection for rectal cancer.

Completeness in the Swedish Fracture Register and the Swedish National Patient Register: An Assessment of Humeral Fracture Registrations

Purpose

Register-based clinical research is important. However, it is essential that the collected data are reliable for the registers to be a valuable source of information. This study evaluated the quality of humeral fracture data in the Swedish Fracture Register (SFR) and in the Swedish National Patient Register (NPR). Furthermore, a model for improved case ascertainment was developed for future validation processes.

Materials and Methods

Data were obtained from the NPR and SFR for all individuals aged ≥16 years with an acute humeral fracture ICD-code treated at Sahlgrenska University Hospital. The true number of humeral fractures (“gold standard”) was determined by cross-linkage between the two registers and a medical charts review. The completeness of registrations in each register was measured as the proportion of registrations compared with the gold standard, and accuracy was measured as positive predictive values (PPV).

Results

The NPR demonstrated a high level of completeness (97%) and lower accuracy (PPV 70%) for acute humeral fractures, whereas the SFR had slightly lower completeness (88%) but perfect accuracy (PPV 100%). The most common systematic error was the registration of re-admissions as acute fractures in the NPR (84% of all erroneous registrations). With this knowledge, an adjustment model for NPR data was constructed to increase the accuracy of fracture registrations (PPV 92%) without excluding valid registrations.

Conclusion

Data from the NPR tend to overestimate the true number of fractures, and proper case selection is needed in order for the data to function as a solid basis for epidemiological research and healthcare planning. In contrast, the SFR constitutes a complete, accurate and efficient source of information.

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Association of day of the week with mortality after elective right hemicolectomy for colon cancer: Case analysis from the National Clinical Database

AIM

We aimed to investigate whether later weekdays are related to worse short-term outcomes after elective right hemicolectomy for colon cancer.

METHODS

We retrospectively analyzed adult patients who underwent elective right hemicolectomy for colon cancer between 2012 and 2017. Records lacking details about surgical mortality were excluded, and multiple imputation was performed for other missing data (variables). The primary endpoint was surgical mortality, defined as the sum of 30-day mortality and in-hospital deaths within 90 days postoperatively. Using 22 clinical variables, hierarchal logistic regression modeling with clustering of patients from the same institutes was performed.

RESULTS

Of the 112 658 patients undergoing elective right hemicolectomy for colon cancer, the 30-day mortality and surgical mortality were 0.6% and 1.1%, respectively. Surgery on Friday was less frequent, accounting for 17.1% of all cases. The occurrence of severe postoperative complications, anastomotic leakage, or unadjusted odds ratio for surgical mortality did not show significant differences between weekdays. A hierarchal logistic regression model identified 19 independent factors for surgical mortality. Adjusted odds ratios for surgical mortality were 1.01 (95% confidence interval: 0.83-1.22, P = .915), 0.86 (95% confidence interval: 0.71-1.05, P = .144), 0.86 (95% confidence interval: 0.71-1.05, P = .408), and 0.83 (95% confidence interval: 0.68-1.03, P = .176) for Tuesday, Wednesday, Thursday, and Friday, respectively, showing no significant differences.

CONCLUSION

This study did not identify an evident difference in surgical mortality between weekdays; a safe elective right hemicolectomy for colon cancer is being offered throughout the week in Japan.

Nationwide study of surgery for primary infected abdominal aortic and common iliac artery aneurysms

BACKGROUND

Primary infected aneurysms of the abdominal aorta and iliac arteries are potentially life-threatening. However, because of the rarity of the disease, its pathogenesis and optimal treatment strategy remain poorly defined.

METHODS

A nationwide retrospective cohort study investigated patients who underwent surgical treatment for a primary infected abdominal aortic and/or common iliac artery (CIA) aneurysm between 2011 and 2017 using a Japanese clinical registry. The study evaluated the relationships between preoperative factors and postoperative outcomes including 90-day and 3-year mortality, and persistent or recurrent aneurysm-related infection. Propensity score matching was used to compare survival between patients who underwent in situ prosthetic grafting and those who had endovascular aneurysm repair (EVAR).

RESULTS

Some 862 patients were included in the analysis. Preceding infection was identified in 30.2 per cent of the patients. The median duration of postoperative follow-up was 639 days. Cumulative overall survival rates at 30 days, 90 days, 1 year, 3 years and 5 years were 94.0, 89.7, 82.6, 74.9 and 68.5 per cent respectively. Age, preoperative shock and hypoalbuminaemia were independently associated with short-term and late mortality. Compared with open repair, EVAR was more closely associated with persistent or recurrent aneurysm-related infection (odds ratio 2.76, 95 per cent c.i. 1.67 to 4.58; P < 0.001). Propensity score-matched analyses demonstrated no significant differences between EVAR and in situ graft replacement in terms of 3-year all-cause and aorta-related mortality rates (P = 0.093 and P =0.472 respectively).

CONCLUSION

In patients undergoing surgical intervention for primary infected abdominal aortic and CIA aneursyms, postoperative survival rates were encouraging. Eradication of infection following EVAR appeared less likely than with open repair, but survival rates were similar in matched patients between EVAR and in situ graft replacement.

Risk prediction model for early outcomes of revascularization for chronic limb-threatening ischaemia

BACKGROUND

Quantifying the risks and benefits of revascularization for chronic limb-threatening ischaemia (CLTI) is important. The aim of this study was to create a risk prediction model for treatment outcomes 30 days after revascularization in patients with CLTI.

METHODS

Consecutive patients with CLTI who had undergone revascularization between 2013 and 2016 were collected from the JAPAN Critical Limb Ischemia Database (JCLIMB). The cohort was divided into a development and a validation cohort. In the development cohort, multivariable risk models were constructed to predict major amputation and/or death and major adverse limb events using least absolute shrinkage and selection operator logistic regression. This developed model was applied to the validation cohort and its performance was evaluated using c-statistic and calibration plots.

RESULTS

Some 2906 patients were included in the analysis. The major amputation and/or mortality rate within 30 days of arterial reconstruction was 5.0 per cent (144 of 2906), and strong predictors were abnormal white blood cell count, emergency procedure, congestive heart failure, body temperature of 38°C or above, and hemodialysis. Conversely, moderate, low or no risk in the Geriatric Nutritional Risk Index (GNRI) and ambulatory status were associated with improved results. The c-statistic value was 0.82 with high prediction accuracy. The rate of major adverse limb events was 6.4 per cent (185 of 2906), and strong predictors were abnormal white blood cell count and body temperature of 38°C or above. Moderate, low or no risk in the GNRI, and age greater than 84 years were associated with improved results. The c-statistic value was 0.79, with high prediction accuracy.

CONCLUSION

This risk prediction model can help in deciding on the treatment strategy in patients with CLTI and serve as an index for evaluating the quality of each medical facility.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Current Status and Issues Associated with Bariatric and Metabolic Surgeries in Japan

Among Asian countries, laparotomic and laparoscopic bariatric surgeries were introduced in Japan after its establishment in Taiwan. However, despite high prevalence of potential patients with obesity and diabetes, the wider incorporation of surgery into treatment regimen has been stalling for decades in Japan. While the unique Japanese national health insurance system has guaranteed fair healthcare delivery, it might have worked as a barrier to the development of bariatric and metabolic surgeries (BMS). The present article reviews the status of BMS in Japan and discusses recent issues related to its use. To focus on and identify the major obstacles inhibiting the widespread use of BMS, we have comprehensively covered some major areas including the insurance system, surgical indication, accreditation and training system, original research, and national registry.

Emergency surgery for gastrointestinal cancer: A nationwide study in Japan based on the National Clinical Database

BACKGROUND

Emergency gastrointestinal surgery, although rare, is known for its high mortality and morbidity. However, the risks of emergency surgery for gastrointestinal cancer have not been investigated in depth. This study aimed to investigate the impact of emergency surgery on mortality and morbidity in patients with gastrointestinal cancers and to identify associated risk factors.

METHODS

We extracted data from the National Clinical Database, a nationwide surgery registration system in Japan, for patients with gastrointestinal cancer who underwent esophageal resection, total gastrectomy, distal gastrectomy, right hemicolectomy, or low anterior resection between 2012 and 2017. The impacts of emergency surgery on 30-day mortality and incidence of overall postoperative complications were compared with those of non-emergency surgery. Risk factors for mortality and overall postoperative complications were then sought in patients who underwent emergency surgery.

RESULTS

Thirty-day mortality and incidence of overall postoperative complications were significantly higher in emergency surgeries for gastric, colon, and rectal cancers than in non-emergency surgeries (odds ratios 4.86-6.98 and 1.68-2.18, respectively; all P < .001). Various risk factors were identified in the group that underwent emergency surgery, including preoperative sepsis and lower body mass index. Some of the risk factors were common to all types of surgery and others were specific to a certain type of surgery.

CONCLUSION

The actual risk of emergency surgery and the risk factors for overall postoperative complications in emergency cases are shown to serve as a reference for postoperative management. Emergency surgery had an additional burden on patients depending on the type of surgery.

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.

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

Purposes

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

Methods

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

Results

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

Conclusions

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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