Prediction of postoperative pancreatic fistula using a nomogram based on the updated definition

Optimizing prediction models for pancreatic fistula after pancreatectomy: Current status and future perspectives

Postoperative pancreatic fistula (POPF) is a frequent complication after pancreatectomy, leading to increased morbidity and mortality. Optimizing prediction models for POPF has emerged as a critical focus in surgical research. Although over sixty models following pancreaticoduodenectomy, predominantly reliant on a variety of clinical, surgical, and radiological parameters, have been documented, their predictive accuracy remains suboptimal in external validation and across diverse populations. As models after distal pancreatectomy continue to be progressively reported, their external validation is eagerly anticipated. Conversely, POPF prediction after central pancreatectomy is in its nascent stage, warranting urgent need for further development and validation. The potential of machine learning and big data analytics offers promising prospects for enhancing the accuracy of prediction models by incorporating an extensive array of variables and optimizing algorithm performance. Moreover, there is potential for the development of personalized prediction models based on patient- or pancreas-specific factors and postoperative serum or drain fluid biomarkers to improve accuracy in identifying individuals at risk of POPF. In the future, prospective multicenter studies and the integration of novel imaging technologies, such as artificial intelligence-based radiomics, may further refine predictive models. Addressing these issues is anticipated to revolutionize risk stratification, clinical decision-making, and postoperative management in patients undergoing pancreatectomy.

A Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis analysis to evaluate the quality of reporting of postoperative pancreatic fistula prediction models after pancreatoduodenectomy: A systematic review

BACKGROUND

Postoperative pancreatic fistula is a frequent and potentially lethal complication after pancreatoduodenectomy. Several models have been developed to predict postoperative pancreatic fistula risk. This study was performed to evaluate the quality of reporting of postoperative pancreatic fistula prediction models after pancreatoduodenectomy using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist that provides guidelines on reporting prediction models to enhance transparency and to help in the decision-making regarding the implementation of the appropriate risk models into clinical practice.

METHODS

Studies that described prediction models to predict postoperative pancreatic fistula after pancreatoduodenectomy were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The TRIPOD checklist was used to evaluate the adherence rate. The area under the curve and other performance measures were extracted if reported. A quadrant matrix chart is created to plot the area under the curve against TRIPOD adherence rate to find models with a combination of above-average TRIPOD adherence and area under the curve.

RESULTS

In total, 52 predictive models were included (23 development, 15 external validation, 4 incremental value, and 10 development and external validation). No risk model achieved 100% adherence to the TRIPOD. The mean adherence rate was 65%. Most authors failed to report on missing data and actions to blind assessment of predictors. Thirteen models had an above-average performance for TRIPOD checklist adherence and area under the curve.

CONCLUSION

Although the average TRIPOD adherence rate for postoperative pancreatic fistula models after pancreatoduodenectomy was 65%, higher compared to other published models, it does not meet TRIPOD standards for transparency. This study identified 13 models that performed above average in TRIPOD adherence and area under the curve, which could be the appropriate models to be used in clinical practice.

Postoperative pancreatitis and pancreatic fistulae: a review of current evidence

OBJECTIVES

Postoperative pancreatic fistula (POPF) represents one of the most severe complications following pancreatic surgery. Despite being a leading cause of morbidity and mortality, its pathophysiology is poorly understood. In recent years, there has been growing evidence to support the role of postoperative or post-pancreatectomy acute pancreatitis (PPAP) in the development of POPF. This article reviews the contemporary literature on POPF pathophysiology, risk factors, and prevention strategies.

METHODS

A literature search was conducted using electronic databases, including Ovid Medline, EMBASE, and Cochrane Library, to retrieve relevant literature published between 2005 and 2023. A narrative review was planned from the outset.

RESULTS

A total of 104 studies fulfilled criteria for inclusion. Forty-three studies reported on technical factors predisposing to POPF, including resection and reconstruction technique and adjuncts for anastomotic reinforcement. Thirty-four studies reported on POPF pathophysiology. There is compelling evidence to suggest that PPAP plays a critical role in the development of POPF. The acinar component of the remnant pancreas should be regarded as an intrinsic risk factor; meanwhile, operative stress, remnant hypoperfusion, and inflammation represent common mechanisms for acinar cell injury.

CONCLUSIONS

The evidence base for PPAP and POPF is evolving. Future POPF prevention strategies should look beyond anastomotic reinforcement and target underlying mechanisms of PPAP development.

Utility of fistula risk score in assessing the risk of postoperative pancreatic fistula occurrence and other significant complications after different types of pancreatic neuroendocrine tumor resections

Purpose

This study was performed to evaluate the utility of the fistula risk score (FRS) and its components in predicting the occurrence of postoperative pancreatic fistula and other significant postoperative complications after resections of pancreatic neuroendocrine tumors.

Methods

Retrospective analysis of 131 patients operated on for pancreatic neuroendocrine tumors between 2015 and 2021 was performed. The correlation of the FRS scale with the occurrence of postoperative pancreatic fistulas and postoperative complications according to the Clavien-Dindo classification was analyzed; only in 109 cases of distal resections and pancreatoduodenectomies (PD).

Results

Soft pancreatic texture and intraoperative blood loss of >700 mL are risk factors for clinically significant pancreatic fistula (P = 0.001 and P = 0.001, respectively) and significant postoperative complications (P = 0.016 and P = 0.001, respectively). Wirsung duct diameter (WDD) was associated only with the occurrence of postoperative pancreatic fistula (P = 0.013). FRS scale is associated with the occurrence of pancreatic fistulas and clinically significant postoperative complications in cases of distal resections and PDs (P < 0.001 and P = 0.005, respectively). Postoperative complications are correlated with the occurrence of fistula type B or C (P < 0.001).

Conclusion

Soft pancreatic texture, intraoperative blood loss of >700 mL, and a WDD of ≤3 mm are risk factors for clinically significant postoperative pancreatic fistula. FRS may be applied not only in PDs but also in distal pancreatectomies. Unfortunately, it is not used in total pancreatic resections and enucleations since FRS takes into account the WDD.

Personal predictive model based on systemic inflammation markers for estimation of postoperative pancreatic fistula following pancreaticoduodenectomy

BACKGROUND

Postoperative pancreatic fistula (PF) is a serious life-threatening complication after pancreaticoduodenectomy (PD). Our research aimed to develop a machine learning (ML)-aided model for PF risk stratification.

AIM

To develop an ML-aided model for PF risk stratification.

METHODS

We retrospectively collected 618 patients who underwent PD from two tertiary medical centers between January 2012 and August 2021. We used an ML algorithm to build predictive models, and subject prediction index, that is, decision curve analysis, area under operating characteristic curve (AUC) and clinical impact curve to assess the predictive efficiency of each model.

RESULTS

A total of 29 variables were used to build the ML predictive model. Among them, the best predictive model was random forest classifier (RFC), the AUC was [0.897, 95% confidence interval (CI): 0.370–1.424], while the AUC of the artificial neural network, eXtreme gradient boosting, support vector machine, and decision tree were between 0.726 (95%CI: 0.191–1.261) and 0.882 (95%CI: 0.321–1.443).

CONCLUSION

Fluctuating serological inflammatory markers and prognostic nutritional index can be used to predict postoperative PF.

Perioperative risk of pancreatic head resection-nomogram-based prediction of severe postoperative complications as a decisional aid for clinical practice

PURPOSE

To develop nomograms for pre- and early-postoperative risk assessment of patients undergoing pancreatic head resection.

METHODS

Clinical data from 956 patients were collected in a prospectively maintained database. A test (n = 772) and a validation cohort (n = 184) were randomly generated. Uni- and multi-variate analysis and nomogram construction were performed to predict severe postoperative complications (Clavien-Dindo Grades III-V) in the test cohort. External validation was performed with the validation cohort.

RESULTS

We identified ASA score, indication for surgery, body mass index (BMI), preoperative white blood cell (WBC) count, and preoperative alkaline phosphatase as preoperative factors associated with an increased perioperative risk for complications. Additionally to ASA score, BMI, indication for surgery, and the preoperative alkaline phosphatase, the following postoperative parameters were identified as risk factors in the early postoperative setting: the need for intraoperative blood transfusion, operation time, maximum WBC on postoperative day (POD) 1-3, and maximum serum amylase on POD 1-3. Two nomograms were developed on the basis of these risk factors and showed accurate risk estimation for severe postoperative complications (ROC-AUC-values for Grades III-V-preoperative nomogram: 0.673 (95%, CI: 0.626-0.721); postoperative nomogram: 0.734 (95%, CI: 0.691-0.778); each p ≤ 0.001). Validation yielded ROC-AUC-values for Grades III-V-preoperative nomogram of 0.676 (95%, CI: 0.586-0.766) and postoperative nomogram of 0.677 (95%, CI: 0.591-0.762); each p = 0.001.

CONCLUSION

Easy-to-use nomograms for risk estimation in the pre- and early-postoperative setting were developed. Accurate risk estimation can support the decisional process, especially for IPMN-patients with an increased perioperative risk.

External validation of postoperative pancreatic fistula prediction scores in pancreatoduodenectomy: a systematic review and meta-analysis

BACKGROUND

Multiple risk scores claim to predict the probability of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy. It is unclear which scores have undergone external validation and are the most accurate. The aim of this study was to identify risk scores for POPF, and assess the clinical validity of these scores.

METHODS

Areas under receiving operator characteristic curve (AUROCs) were extracted from studies that performed external validation of POPF risk scores. These were pooled for each risk score, using intercept-only random-effects meta-regression models.

RESULTS

Systematic review identified 34 risk scores, of which six had been subjected to external validation, and so included in the meta-analysis, (Tokyo (N=2 validation studies), Birmingham (N=5), FRS (N=19), a-FRS (N=12), m-FRS (N=3) and ua-FRS (N=3) scores). Overall predictive accuracies were similar for all six scores, with pooled AUROCs of 0.61, 0.70, 0.71, 0.70, 0.70 and 0.72, respectively. Considerably heterogeneity was observed, with I2 statistics ranging from 52.1-88.6%.

CONCLUSION

Most risk scores lack external validation; where this was performed, risk scores were found to have limited predictive accuracy. . Consensus is needed for which score to use in clinical practice. Due to the limited predictive accuracy, future studies to derive a more accurate risk score are warranted.

A reinforced suture method for stapled gastrointestinal anastomosis to reduce gastrointestinal hemorrhage during Whipple operation in laparoscopy

Purpose

Laparoscopy is being increasingly accepted for pancreaticoduodenectomy. Stapled anastomosis (SA) is used extensively to facilitate laparoscopic pancreaticoduodenectomy (LPD); however, the incidence of anastomotic bleeding after stapled gastrointestinal anastomosis is still high.

Methods

One hundred and thirty-nine patients who underwent LPD using Whipple method were enrolled in our study. We performed the SA with our reinforced method (n = 68, R method) and without the method (n = 71, NR method). We compared the clinical characteristics and anastomosis methods of patients with or without gastrointestinal-anastomotic hemorrhage (GAH), and operative parameters were also compared between the anastomotic methods.

Results

Of the 139 patients undergoing LPD, 15 of them developed GAH. The clinical characteristics of patients with or without GAH were not significantly different except in the anastomotic method (P < 0.001). In the univariate logistic regression analyses, only the anastomotic method was associated with GAH. Furthermore, patients with the NR method had significantly higher incidences of GAH (P < 0.001) and Clavien-Dindo grade ≥ III complications (P < 0.001).

Conclusion

Our retrospective analysis showed that the SA performed with reinforced method might be a reform of SA without the reinforcement, as indicated by the lower incidence of GAH. However, further research is necessary to evaluate the utility of this reinforced method.

Role of extracellular matrix structural components and tissue mechanics in the development of postoperative pancreatic fistula

Radical resection remains the only curative treatment option in pancreatic cancer. Postoperative pancreatic fistulas (POPF) occur in up to 30% of patients leading to prolonged hospital-stay, increased cost of care and morbidity and mortality. Mechanical properties of the pancreas are associated with POPF. The aim of this study is to analyze the role of extracellular matrix (ECM) and tissue mechanics in the risk of POPF. Biopsies of 41 patients receiving a partial pancreas-resection are analyzed. Clinical data, ECM components and mechanical properties are correlated with POPF. Preoperative cholestasis is correlated with reduced risk of POPF, which comes along with a dilatation of the pancreatic duct and significantly higher content of collagen I. Patients developing POPF exhibited a degenerated tissue integrity, with significantly lower content of fibronectin and a trend for lower collagen I, III, IV and hyaluronic acid. This correlated with a soft tactile sensation of the surgeon during the intervention. However, this was not reflected with tissue mechanics evaluated by ex vivo uniaxial compression testing, where a significantly higher elastic modulus and no effect on the stress relaxation time were found. In conclusion, patients with cholestasis seem to have a lower risk for POPF, and an increase in collagen I. A degenerated matrix with lower content of structural ECM components correlates with increased risk of POPF. However, ex vivo uniaxial compression testing failed to clearly explain the link of ECM properties and POPF.

The comparation of short-term outcome between laparoscopic and open pancreaticoduodenectomy: a propensity score matching analysis

Pancreaticoduodenectomy (PD) is one of the most complex and delicate operations in abdominal surgery. With the development of laparoscopic techniques, more and more pancreatic experts have become skilled in laparoscopic pancreaticoduodenectomy (LPD). However, the short-term efficacy of LPD compared to open pancreaticoduodenectomy (OPD) remains unclear. Here, we performed a propensity score matching study aiming to compare the short outcomes of patients who underwent LPD or OPD after the learning curve and established a risk model of pancreatic fistula. The data of 346 patients who had OPD or LPD from July 2015 to January 2020 were retrieved. After a 1:1 matching, 224 patients remained. The operation time was significantly longer (P = 0.001) but the amount of bleeding was significantly lower (P = 0.001) in the LPD group than in the OPD group. Patients in LPD group had fewer blood transfusions (P = 0.002) than those in OPD group. More lymph nodes (P < 0.001) were dissected in LPD group. The rate of grade B/C pancreatic fistula was significantly higher in the LPD group than in the OPD group (16.1% vs. 6.3%, P = 0.002). By multi variate Logistic regression analysis, we identified pancreatic tumor, malignancy and low body mass index were risk factors of Grade B/C pancreatic fistula after PD operation. Then, we developed a Grade B/C pancreatic fistula nomogram with the risk factors. The C-index of the nomogram was 0.836 (95% CI 0.762-0.910). In conclusion, LPD could be technically feasible, get less trauma and achieve similar short-term outcome as compared with OPD.

Nomogram for predicting overall survival in children with neuroblastoma based on SEER database

Purpose

This study was performed to establish and validate a nomogram for predicting the overall survival in children with neuroblastoma.

Methods

The latest clinical data of neuroblastoma in Surveillance, Epidemiology, and End Results (SEER) database was extracted from 2000 to 2016. The cases included were randomly divided into training and validation cohorts. The survival curves were drawn with a Kaplan-Meier estimator to investigate the influences of certain single factors on overall survival. Also, least absolute shrinkage and selection operator regression was applied to further select the prognostic variables for neuroblastoma. Additionally, receiver operating characteristic (ROC) curves and calibration curves were used to evaluate the accuracy of the nomogram.

Results

In total, 1,262 patients were collected and 8 independent prognostic factors were achieved, including patients' age, sex, race, tumor grade, radiotherapy, chemotherapy, tumor site, and tumor size. Then we constructed a nomogram by using the data of the training cohort with 886 cases. Subsequently, the nomogram was validated internally and externally with 886 and 376 cases, respectively. The internal validation revealed that the area under the curves (AUC) of ROC curves of 1-, 3-, and 5-year overall survival were 0.69, 0.78, and 0.81, respectively. Accordingly, the external validation also showed that the AUC of 1-, 3-, and 5-year overall survival were all ≥0.69. Both methods of validation demonstrated that the predictive calibration curves were consistent with standard curves.

Conclusion

The nomogram possess the potential to be a new tool in predicting the survival rate of neuroblastoma patients.