Drain output volume after pancreaticoduodenectomy is a useful warning sign for postoperative complications

Venous resection increases risk of chyle leak after total pancreatectomy for pancreatic tumors

BACKGROUND

Existing research on chyle leak (CL) after pancreatic surgery is mostly focused on pancreaticoduodenectomy and lacks investigation on total pancreatectomy (TP). This study aimed to explore potential risk factors of CL and develop a predictive model for patients with pancreatic tumor undergoing TP.

METHODS

This retrospective study enrolled 90 consecutive patients undergoing TP from January 2015 to December 2023 at Peking Union Medical College Hospital. According to the inclusion criteria, 79 patients were finally included in the following analysis. The LASSO regression and multivariate logistic regression analysis were performed to identify risk factors associated with CL and construct a predictive nomogram. Then, the ROC analysis, calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were performed to assess its discrimination, accuracy, and efficacy. Due to the small sample size, we adopted the bootstrap resampling method with 500 repetitions for validation. Lastly, we plotted and analyzed the trend of postoperative drainage volume in CL patients.

RESULTS

We revealed that venous resection (OR = 4.352, 95%CI 1.404-14.04, P = 0.011) was an independent risk factor for CL after TP. Prolonged operation time (OR = 1.473, 95%CI 1.015-2.237, P = 0.052) was also associated with an increased incidence of CL. We included these two factors in our prediction model. The area under the curve (AUC) was 0.752 (95%CI 0.622-0.874) after bootstrap. The calibration curve, DCA and CIC showed great accuracy and clinical benefit of our nomogram. In patients with CL, the mean drainage volume was significantly higher in venous resection group and grade B CL group.

CONCLUSION

Venous resection was an independent risk factor for chyle leak after TP. Patients undergoing vascular resection during TP should be alert for the occurrence of CL after surgery. We then constructed a nomogram consisted of venous resection and operation time to predict the odds of CL in patients undergoing TP.

Adjusting Drain Fluid Amylase for Drain Volume Does Not Improve Pancreatic Fistula Prediction

INTRODUCTION

Drain fluid amylase (DFA) levels have been used to predict clinically relevant postoperative pancreatic fistula (CR-POPF) and guide postoperative drain management. Optimal DFA cutoff thresholds vary between studies, thereby prompting investigation of an alternative assessment technique. As DFA measurements could, in theory, be distorted by variations in ascites fluid production, we hypothesized that adjusting DFA for volume corrected drain fluid amylase (vDFA) would improve CR-POPF predictive models.

METHODS

A single-institution retrospective cohort study of patients, who underwent pancreatoduodenectomies (PD) and distal pancreatectomies (DP) between 2013 and 2019, was performed. DFAs and vDFAs were measured on postoperative day (POD) 3. Clinicopathologic variables were compared between cohorts by univariable and multivariable analyses and Receiver operating characteristic (ROC) curves.

RESULTS

Patients developing a CR-POPF were more likely to be male and have elevated DFA, vDFA, and body mass index (BMI). vDFA use did not contribute to a superior CR-POPF predictive model compared to DFA-a finding consistent on subanalysis of surgery type PD versus DP. In CR-POPF predictive models, DFA, vDFA, and male sex significantly improved CR-POPF predictive models when considering both surgery subtypes, while only DFA and vDFA significantly improved models when cohorts were segregated by surgery type.

CONCLUSIONS

Postoperative DFA remains a preferred method of predicting CR-POPF as the proposed vDFA assessment technique only adds complexity without increased discriminability.

Impact of Drain Position on Drain Fluid Amylase, Fluid Collection and Postoperative Pancreatic Fistula after Distal Pancreatectomy

BACKGROUND

The current definition for postoperative pancreatic fistula (POPF) is based on the drain fluid amylase (DFA), and drains must be positioned adequately. We investigated the impact of DFA level, drain position and fluid collection after distal pancreatectomy (DP).

METHODS

We performed a retrospective study of 516 patients who underwent DP between June 2004 and December 2018. Patients were excluded if DP was not main procedure, DFA was not measured, postoperative computed tomography (CT) was not performed, or drains were removed before CT. Demographic and perioperative data were analyzed in 422 eligible patients.

RESULTS

Of 422 patients, 49(11.6%) had clinically relevant (CR)-POPF and 102(24.2%) had a malpositioned drain. There was no difference in CR-POPF rate between the high and low DFA groups (12.6% vs 10.7%, P = 0.649). Drain malposition was more frequently associated with symptomatic fluid collection and CR-POPF than well-positioned drains. Male sex, high body mass index, transfusion, and drain malposition were CR-POPF risk factors. In subgroup analysis, drain malposition was also an independent risk factor for CR-POPF in the low DFA group.

CONCLUSIONS

After DP, the incidence of CR-POPF in the high and low DFA groups was similar and drain malposition increased the risk of CR-POPF. Thus, the ISGPS definition of POPF based on DFA levels is limited in DP, and DFA levels should be interpreted together with the drain position.

Machine learning algorithms as early diagnostic tools for pancreatic fistula following pancreaticoduodenectomy and guide drain removal: A retrospective cohort study

OBJECTIVE

Clinically relevant postoperative pancreatic fistula (CR-POPF) remains the major cause of morbidity following pancreaticoduodenectomy (PD). Several model score systems such as the Fistula Risk Score (FRS) have been developed to predict CR-POPF using preoperative and intraoperative data. Machine learning (ML) algorithms are increasingly applied in the medical field and they could be used to assess the risk of CR-POPF, identify clinically meaningful data and guide drain removal.

METHODS

Data from consecutive patients who underwent PD between January 1, 2010 and March 31, 2021 at a single high-volume center was collected retrospectively in this study. Demographics, clinical features, intraoperative parameters, and laboratory values were used to conduct the ML model. Four different ML algorithms (CatBoost, lightGBM, XGBoost and Random Forest) were used to train this model with cross-validation.

RESULTS

A total of 2421 patients with 62 clinical parameters were enrolled in this ML model. The majority of patients (76.3%) underwent open PD while others underwent robot-assisted PD. CR-POPF occurred in 424 (17.5%) patients. The CatBoost algorithm outperformed other algorithms with a mean area under the receiver operating characteristic curve (AUC) of 0.81 (95% confidence interval: 0.80-0.82) from the 5-fold cross-validation procedure. In the test dataset, the CatBoost algorithm also achieved the best mean-AUC of 0.83. The most important value was mean drain fluid amylase (DFA) in the first seven postoperative days (POD). The performance of models that used only preoperative data and intraoperative data was marginally lower than that of models that used combined data.

CONCLUSION

Our ML algorithms could be applied as early diagnostic tools for CR-POPF in patients who underwent PD. Such real-time clinical decision support tools can identify patients with a high risk of CR-POPF, help in developing the perioperative management plan and guide the optimal timing of drain removal.

Incidence and risk factors for Chyle leak after pancreatic surgery for cancer: A comprehensive systematic review

BACKGROUND

Chyle leak (CL) is a clinically relevant complication after pancreatectomy. Its incidence and the associated risk factors are ill defined, and various treatments options have been described. There is no consensus, however, regarding optimal management. The present study aims to systematically review the literature on CL after pancreatectomy.

METHODS

A systematic review from PubMed, Scopus and Embase database was performed. Studies using a clear definition for CL and published from January 2000 to January 2021 were included. The PRISMA guidelines were followed during all stages of this systematic review. The MINORS score was used to assess methodological quality.

RESULTS

Literature search found 361 reports, 99 of which were duplicates. The titles and abstracts of 262 articles were finally screened. The references from the remaining 181 articles were manually assessed. After the exclusions, 43 articles were thoroughly assessed. A total of 23 articles were ultimately included for this review. The number of patients varied from 54 to 3532. Incidence of post pancreatectomy CL varied from 1.3% to 22.1%. Main risk factors were the extent of the surgery and early oral or enteral feeding. CL dried up spontaneously or after conservative management within 14 days in 53% to 100% of the cases.

CONCLUSIONS

The extent of surgery is the most common predictor of risk of CL. Conservative treatment has been shown to be effective in most cases and can be considered the treatment of choice. We propose a management algorithm based on the current available evidence.

Diagnostic value of C-reactive protein and procalcitonin for postoperative pancreatic fistula following pancreatoduodenectomy: a systematic review and meta-analysis

BACKGROUND

C-reactive protein (CRP) and procalcitonin (PCT) have recently been used to diagnose and screen for postoperative pancreatic fistula (POPF) following pancreatoduodenectomy (PD), but their reliability is still unclear. Our study aims to assess the efficacy of CRP and PCT in the diagnosis of POPF after PD.

METHODS

Electronic databases such as PubMed, Excerpta Medica (EMBASE), the Web of Science (WOS) and the China National Knowledge Infrastructure (CNKI) were used to search for studies and full-text articles that assessed the diagnostic efficacy of CRP and PCT for POPF. Review Manager 5.4 and STATA 14.0 were used to estimate the pooled diagnostic value of CRP and PCT. Sensitivity analyses and Deeks' funnel plot tests were conducted on the selected studies.

RESULTS

Twenty studies that satisfied the established selection criteria were chosen. Both CRP and PCT were shown to be highly effective in diagnosing POPF, each with a high area under the curve (AUC). The AUC of CRP on postoperative day (POD) 4 had a value of 0.86, with a sensitivity and specificity of 0.85 and 0.69, respectively. The AUC of PCT on POD 5 had a value of 0.87, with a sensitivity and specificity of 0.84 and 0.74, respectively.

DISCUSSION

Our research supports the hypothesis that CRP and PCT are valuable diagnostic tools for predicting POPF, especially given the CRP levels on POD 4 and PCT levels on POD 5. Limited by the small number of the studies analyzed herein, we recommend that more randomized controlled trials be performed to verify our conclusions.