Novel Calculator to Estimate the Risk of Clinically Relevant Postoperative Pancreatic Fistula Following Distal Pancreatectomy

Optimal cutoff values of drain amylase for predicting pancreatic fistula are different between open and laparoscopic distal pancreatectomy

BACKGROUND

Drainage fluid amylase (DFA) is useful for predicting clinically relevant postoperative pancreatic fistula (CR-POPF) after distal pancreatectomy (DP). However, difference in optimal cutoff value of DFA for predicting CR-POPF between open DP (ODP) and laparoscopic DP (LDP) has not been investigated. This study aimed to identify the optimal cutoff values of DFA for predicting CR-POPF after ODP and LDP.

METHODS

Data for 294 patients (ODP, n = 127; LDP, n = 167) undergoing DP at Kobe University Hospital between 2010 and 2021 were reviewed. Propensity score matching was performed to minimize treatment selection bias. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff values of DFA for predicting CR-POPF for ODP and LDP. Logistic regression analysis for CR-POPF was performed to investigate the diagnostic value of DFA on postoperative day (POD) three with identified cutoff value.

RESULTS

In the matched cohort, CR-POPF rates were 24.7% and 7.9% after ODP and LDP, respectively. DFA on POD one was significantly lower after ODP than after LDP (2263 U/L vs 4243 U/L, p < 0.001), while the difference was not significant on POD three (543 U/L vs 1221 U/L, p = 0.171). ROC analysis revealed that the optimal cutoff value of DFA on POD one and three for predicting CR-POPF were different between ODP and LDP (ODP, 3697 U/L on POD one, 1114 U/L on POD three; LDP, 10564 U/L on POD one, 6020 U/L on POD three). Multivariate analysis showed that DFA on POD three with identified cutoff value was the independent predictor for CR-POPF both for ODP and LDP.

CONCLUSIONS

DFA on POD three is an independent predictor for CR-POPF after both ODP and LDP. However, the optimal cutoff value for it is significantly higher after LDP than after ODP. Optimal threshold of DFA for drain removal may be different between ODP and LDP.

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.

Which Factors Are Associated with Distal Pancreatectomy Outcomes' Optimization with the Application of an Enhanced Recovery After Surgery Program?

Background: Distal pancreatectomy (DP) represents the best therapeutic option for patients with body-tail pancreatic neoplasms (PNs). The enhanced recovery after surgery protocol is widely used for treating patients with PN to speed up postoperative recovery. This study aims to describe our institute's experience in the application of fast recovery protocol in a cohort of patients treated with DP, identifying predictors facilitating a decrease in the length of hospital stay. Patient and Methods: Were retrospectively enrolled 60 consecutive cases of DP performed from January 2016 to June 2022 in patients treated with enhanced recovery protocol, 25% of them were treated with spleen preserving procedure. Single-variable logistic regression models were used to evaluate the potential association between patient characteristics and the probability of postoperative complications. Standard linear regression models were used for length of stay, number of postoperative days (PODs) from surgery to full bowel function recovery, and PODs to the interruption of intravenous analgesia administration. Results: Thirty-four (57%) patients underwent open surgery and 26 (43%) laparoscopic surgery. Patients who underwent laparoscopic surgery and spleen-preserving procedures experienced a lower complication rate (P = .037), shorter length of stay, and time of analgesic requirements. With single-variable logistic regression models patients treated with laparoscopic surgery had statistically significant higher recovery times in terms of nasogastric tube removal (P = .004) and early enteral nutrition (P = .001). Conclusion: Continual refinement with enhanced recovery protocol for treating PN patients based on perioperative counseling and surgical decision-making is crucial to reduce patient morbidity and time for recovery.

A Machine Learning Approach to Predict Postoperative Pancreatic Fistula After Pancreaticoduodenectomy Using Only Preoperatively Known Data

BACKGROUND

Clinically-relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD) is a major postoperative complication and the primary determinant of surgical outcomes. However, the majority of current risk calculators utilize intraoperative and postoperative variables, limiting their utility in the preoperative setting. Therefore, we aimed to develop a user-friendly risk calculator to predict CR-POPF following PD using state-of-the-art machine learning (ML) algorithms and only preoperatively known variables.

METHODS

Adult patients undergoing elective PD for non-metastatic pancreatic cancer were identified from the ACS-NSQIP targeted pancreatectomy dataset (2014-2019). The primary endpoint was development of CR-POPF (grade B or C). Secondary endpoints included discharge to facility, 30-day mortality, and a composite of overall and significant complications. Four models (logistic regression, neural network, random forest, and XGBoost) were trained, validated and a user-friendly risk calculator was then developed.

RESULTS

Of the 8666 patients who underwent elective PD, 13% (n = 1160) developed CR-POPF. XGBoost was the best performing model (AUC = 0.72), and the top five preoperative variables associated with CR-POPF were non-adenocarcinoma histology, lack of neoadjuvant chemotherapy, pancreatic duct size less than 3 mm, higher BMI, and higher preoperative serum creatinine. Model performance for 30-day mortality, discharge to a facility, and overall and significant complications ranged from AUC 0.62-0.78.

CONCLUSIONS

In this study, we developed and validated an ML model using only preoperatively known variables to predict CR-POPF following PD. The risk calculator can be used in the preoperative setting to inform clinical decision-making and patient counseling.

Postoperative Opioid Use Is Associated with Increased Rates of Grade B/C Pancreatic Fistula After Distal Pancreatectomy

BACKGROUND

Clinically relevant postoperative pancreatic fistula (CR-POPF) is a major source of morbidity after distal pancreatectomy. This study examined the association between postoperative opioid use and CR-POPF in the context of opioid-sparing postoperative care.

METHODS

A case-control study was performed on consecutive patients who underwent distal pancreatectomy between October 2016 and April 2022 at a single institution. Patients who developed CR-POPF were compared to controls. Multivariable regression modeling was used to identify factors associated with CR-POPF.

RESULTS

A total of 281 patients underwent 187 open, 20 laparoscopic, and 74 robotic-assisted operations. The rate of CR-POPF was 21% (n = 58). CR-POPF rate declined from 32 to 8% over the study period (p < 0.001). Median oral morphine equivalents (OME) administered on POD 0-1 and 0-3 were 94 and 129 mg, respectively, in patients who did not develop a fistula versus 130 and 180 mg in those who did (both p ≤ 0.001). POD 0-3 OME (OR 1.11, p = 0.044) was independently associated with increased odds of CR-POPF, with each additional 50 mg (equivalent to 10 tramadol pills) increasing the relative risk by 11% and absolute risk by 2%.

CONCLUSION

Early postoperative opioid use after distal pancreatectomy was associated with increased odds of CR-POPF. Decreasing perioperative opioid use through enhanced postoperative management is a low-cost and generalizable approach that may reduce rates of CR-POPF after distal pancreatectomy.

Obesity Is Associated With Increased Risk for Adverse Postoperative Outcomes After Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Conflicting reports exist about the effect obesity has on adverse postoperative surgical outcomes after distal pancreatectomy (DP). The aim of this study is to explore the role of obesity in terms of morbidity and pancreas-specific complications following DP for pancreatic ductal adenocarcinoma (PDAC).

METHODS

All patients who underwent DP at a single institution over 10 y were analyzed (2009-2020). Patients were categorized as nonobese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). Independent predictors of adverse postoperative outcomes were calculated using multivariate logistic regression models. Overall survival was assessed using Kaplan-Meier survival analysis.

RESULTS

Of the 178 patients included, 58 (32.5%) were obese. Clinically relevant postoperative pancreatic fistula (CR-POPF) formation rate was significantly higher in the obese group (20.6% versus 7.5%, P value = 0.011). We did not identify any significant difference between obese and nonobese patients in median overall survival (30.2 mon versus 28.9 mon, P value = 0.811). On multivariate binary logistic regression analysis, BMI ≥ 30 was an independent predictor of morbidity (any complication) and CR-POPF formation after DP for PDAC.

CONCLUSIONS

Obesity is associated with a significantly increased risk for CR-POPF in patients undergoing DP for PDAC. Obesity should be considered as a variable in fistula risk calculators for DP.