"Real-time" risk models of postoperative morbidity and mortality for liver transplants

Postoperative plasma presepsin as a biomarker of postoperative infectious complications in different surgical departments: A meta-analysis and systematic review

BACKGROUND

High rates of postoperative infection persist after different surgical procedures, encompassing surgical site infections (SSIs), remote infections, sepsis, and septic shock. Our aim was to assess presepsin's diagnostic accuracy for postoperative infections in patients across surgical procedures.

METHOD

We conducted a comprehensive search in seven databases, extracting data independently. Using STATA 14.0, we calculated pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and Under the receiver operator curve and 95 ​% confidence interval (AUC, 95 ​% CI) as primary outcomes, with secondary outcomes involving sensitivity and specificity in subgroup analyses.

RESULTS

This meta-analysis of 14 studies (1891 cases) evaluated presepsin's diagnostic value for postoperative infectious complications. Results include sensitivity of 77 ​% (70-83), specificity of 81 ​% (71-88), DOR of 14 (8-26), AUC of 84 (80-87), PLR of 4 (3-6), and NLR of 0.28 (0.21-0.38). Presepsin exhibits promise as a diagnostic tool for postoperative infections.

CONCLUSION

In summary, compared to conventional markers like C-reactive protein (CRP) and procalcitonin (PCT), presepsin demonstrated superior sensitivity and specificity for detecting postoperative infectious complications across various surgical procedures.

Achieving clinically optimal balance between accuracy and simplicity of a formula for manual use: Development of a simple formula for estimating liver graft weight with donor anthropometrics

In developing a formula for manual use in clinical settings, simplicity is as important as accuracy. Whole-liver (WL) mass is often estimated using demographic and anthropometric information to calculate the standard liver volume or recommended graft volume in liver transplantation. Multiple formulas for estimating WL mass have been reported, including those with multiple independent variables. However, it is unknown whether multivariable models lead to clinically meaningful improvements in accuracy over univariable models. Our goal was to quantitatively define clinically meaningful improvements in accuracy, which justifies an additional independent variable, and to identify an estimation formula for WL graft weight that best balances accuracy and simplicity given the criterion. From the Japanese Liver Transplantation Society registry, which contains data on all liver transplant cases in Japan, 129 WL donor-graft pairs were extracted. Among the candidate models, those with the smallest cross-validation (CV) root-mean-square error (RMSE) were selected, penalizing model complexity by requiring more complex models to yield a ≥5% decrease in CV RMSE. The winning model by voting with random subsets was fitted to the entire dataset to obtain the final formula. External validity was assessed using CV. A simple univariable linear regression formula using body weight (BW) was obtained as follows: WL graft weight [g] = 14.8 × BW [kg] + 439.2. The CV RMSE (g) and coefficient of determination (R2) were 195.2 and 0.548, respectively. In summary, in the development of a simple formula for manually estimating WL weight using demographic and anthropometric variables, a clinically acceptable trade-off between accuracy and simplicity was quantitatively defined, and the best model was selected using this criterion. A univariable linear model using BW achieved a clinically optimal balance between simplicity and accuracy, while one using body surface area performed similarly.

Real-time mortality risk calculator following pancreatoduodenectomy: quantifying the impact of perioperative events

BACKGROUND

Estimation of mortality risk traditionally has only included preoperative factors. We sought to develop "real-time" mortality risk-calculator for patients who undergo pancreatoduodenectomy (PD) based on preoperative factors, as well as events that occurred during the course of patient's surgery and hospitalization.

METHODS

Patients who underwent PD from 2014 to 2018 were identified in the ACS-NSQIP dataset. Training and validation cohorts were created. Pre-, intra-, and post-operative models to predict 30-day mortality were developed based on perioperative variables selected by stepwise cox regression analyses; model performance was assessed using AUC.

RESULTS

Among 17,683 patients who underwent PD, 1.6% died within 30-days. Patient factors and events associated with 30-day mortality were incorporated into a risk calculator (https://ktsahara.shinyapps.io/Real-timePD/). The accuracy of the risk-calculator increased relative to hospital time-course in both the training (AUC, pre-:0.696, intra-:0.724, post-operative:0.871) and validation (AUC, pre-:0.681, intra-:0.702, post-operative:0.850) cohorts. One in 3 patients had a concordant calculated risk of mortality using pre-versus postoperative variables to inform the risk model (kappa = 0.474).

CONCLUSION

Risk of mortality fluctuated over the hospital course following PD and preoperative risk assessment was often discordant with risk assessed at other periods. The proposed "real-time" calculator may help better stratify patients with increased risk of 30-day mortality.

Diagnostic Utility of Presepsin in Infections After Liver Transplantation: A Preliminary Study

BACKGROUND Infectious complications after solid organ transplantation can be fatal, and early diagnosis and intervention are important. To the best of our knowledge, no study has examined the diagnostic utility of presepsin, a known accurate biomarker, for infectious complications after liver transplantation. This study aimed to evaluate the utility of presepsin for detecting infection and perioperative kinetics of presepsin after liver transplantation. MATERIAL AND METHODS This single-institutional prospective, observational study included 13 patients who underwent living-donor or deceased-donor liver transplantation. Perioperative serum presepsin level was measured 6 times within a week to evaluate its association with infectious complications and compare it with procalcitonin and C-reactive protein levels and leukocyte count. Postoperatively, patients were followed up for 15 days for infectious complications. RESULTS Five of the 13 patients developed infectious complications after liver transplantation. The median time for infection diagnosis was 9 postoperative days (25th-75th percentile, 7-10). Presepsin levels on 5 and 7 postoperative days were significantly higher in patients with infection than in those without (P=0.019 and P=0.011, respectively). In receiver operating characteristic analysis, area under the curve values of presepsin on 5 and 7 postoperative days (0.881 and 0.905, respectively) were higher than those of other biomarkers. The optimal cut-off value of presepsin was 1361 pg/mL on postoperative day 5 and 1375 pg/mL on postoperative day 7. CONCLUSIONS Although this study included a small number of patients, presepsin levels on postoperative days 5 and 7 may be useful indicators for infectious complications after liver transplantation.

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.

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

Background

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

Methods

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

Results

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

Conclusions

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

Prognostic impact of LY6K and CDCA1 expression for patients with esophageal squamous cell carcinoma

AIM

In the present study, we investigated the relationship between the expressions of two cancer testis antigens (CTA), LY6K (lymphocyte antigen 6 complex locus K) and CDCA1 (cell division cycle associated 1), in esophageal squamous cell carcinoma (ESCC) tumors and the long-term outcomes of patients with ESCC to clarify the clinical significance of LY6K and CDCA1 expression in ESCC tumors.

METHODS

A total of 175 patients with thoracic ESCC who had undergone a thoracic esophagectomy with three-field lymphadenectomy without neoadjuvant therapy were retrospectively reviewed in this study. LY6K and CDCA1 expressions were evaluated in tumor tissues using immunohistochemical (IH) staining.

RESULTS

Median patient age was 63 years; 159 patients (90.9%) were men. Ninety-four patients (55.3%) were LY6K-positive, and 85 patients (48.6%) were CDCA1-positive. The LY6K-positive group had a significantly worse overall survival (OS) than the LY6K-negative group (P = 0.012), and the CDCA1-positive group had a significantly worse OS than the CDCA1-negative group (P = 0.010). A multivariate analysis suggested that pathological N stage, venous invasion, LK6Y-positive and CDCA1-positive were independent prognostic factors. The patients were classified into four groups according to the staining pattern combinations of the two CTA. The LY6K-positive and CDCA1-positive group was found to have a significantly poorer outcome than the other groups.

CONCLUSION

ESCC patients with a combination of LY6K and CDCA1 expression in their tumor tissues had a worse prognosis than all the other ESCC patients and it was an independent factor associated with prognosis for patients with ESCC.

Machine learning predicts unpredicted deaths with high accuracy following hepatopancreatic surgery

Background

Machine learning to predict morbidity and mortality-especially in a population traditionally considered low risk-has not been previously examined. We sought to characterize the incidence of death among patients with a low estimated morbidity and mortality risk based on the National Surgical Quality Improvement Program (NSQIP) estimated probability (EP), as well as develop a machine learning model to identify individuals at risk for "unpredicted death" (UD) among patients undergoing hepatopancreatic (HP) procedures.

Methods

The NSQIP database was used to identify patients who underwent elective HP surgery between 2012-2017. The risk of morbidity and mortality was stratified into three tiers (low, intermediate, or high estimated) using a k-means clustering method with bin sorting. A machine learning classification tree and multivariable regression analyses were used to predict 30-day mortality with a 10-fold cross validation. C statistics were used to compare model performance.

Results

Among 63,507 patients who underwent an HP procedure, median patient age was 63 (IQR: 54-71) years. Patients underwent either pancreatectomy (n=38,209, 60.2%) or hepatic resection (n=25,298, 39.8%). Patients were stratified into three tiers of predicted morbidity and mortality risk based on the NSQIP EP: low (n=36,923, 58.1%), intermediate (n=23,609, 37.2%) and high risk (n=2,975, 4.7%). Among 36,923 patients with low estimated risk of morbidity and mortality, 237 patients (0.6%) experienced a UD. According to the classification tree analysis, age was the most important factor to predict UD (importance 16.9) followed by preoperative albumin level (importance: 10.8), disseminated cancer (importance: 6.5), preoperative platelet count (importance: 6.5), and sex (importance 5.9). Among patients deemed to be low risk, the c-statistic for the machine learning derived prediction model was 0.807 compared with an AUC of only 0.662 for the NSQIP EP.

Conclusions

A prognostic model derived using machine learning methodology performed better than the NSQIP EP in predicting 30-day UD among low risk patients undergoing HP surgery.

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

OBJECTIVES

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

SUMMARY BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development and validation of a real-time mortality risk calculator before, during and after hepatectomy: an analysis of the ACS NSQIP database

BACKGROUND

Although most conventional risk prediction models have been based on preoperative information, intra- and post-operative events may be more relevant to mortality after surgery. We sought to develop a mortality risk calculator based on real time characteristics associated with hepatectomy.

METHODS

Patients who underwent hepatectomy between 2014 and 2017 were identified in the ACS-NSQIP dataset. Three prediction models (pre-, intra-, post-operative) were developed and validated using perioperative data.

RESULTS

Among 14,720 patients, 197 (1.3%) experienced 30-day mortality. The predictive ability of the real-time mortality risk calculator was very good based on only preoperative factors (AUC; training cohort: 0.813, validation cohort: 0.731). Incorporating intra-operative variables into the model increased the AUC (training: 0.838, validation: 0.777), while the post-operative model achieved an AUC of 0.922 in the training and 0.885 in the validation cohorts, respectively. While patients with low preoperative risk had only very small fluctuations in the estimated 30-day mortality risk during the intraoperative (Δ0.4%) and postoperative (Δ0.6%) phases, patients who were already deemed high risk preoperatively had additional increased mortality risk based on factors that occurred in the intraoperative (Δ5.4%) and postoperative (Δ9.3%) periods.

CONCLUSION

A real-time mortality risk calculator may better help clinicians identify patients at risk of death at the different stages of the surgical episode.

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.

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

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