Impact of Fatty Pancreas on Postoperative Pancreatic Fistulae: A Meta-Analysis

Development and validation of a novel nomogram to predict postoperative pancreatic fistula after pancreatoduodenectomy using lasso-logistic regression: an international multi-institutional observational study

BACKGROUND

Existing prediction models for clinically relevant postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) lack discriminatory power or are too complex. This study aimed to develop a simple nomogram that could accurately predict clinically relevant POPF after PD.

METHODS

A high-volume, multicenter cohort of patients who underwent PD from the American College of Surgeons-National Surgical Quality Improvement Program database in the United States during 2014-2017 was used as the model training cohort ( n =3609), and patients who underwent PD from the Pancreatic Center of the National Cancer Center Hospital in China during 2014-2019 were used as the external validation cohort ( n =1347). The study used lasso penalized regression to screen large-scale variables, then logistic regression was performed to screen the variables and build a model. Finally, a prediction nomogram for clinically relevant POPF was established based on the logistic model, and polynomial equations were extracted. The performance of the nomogram was evaluated by receiver operating characteristic curve, calibration curve, and decision curve analysis.

RESULTS

In the training and validation cohorts, there were 16.7% (601/3609) and 16.6% (224/1347) of patients who developed clinically relevant POPF, respectively. After screening using lasso and logistic regression, only six predictors were independently associated with clinically relevant POPF, including two preoperative indicators (weight and pancreatic duct size), one intraoperative indicator (pancreatic texture), and three postoperative indicators (deep surgical site infection, delayed gastric emptying, and pathology). The prediction of the new nomogram was accurate, with an area under the curve of 0.855 (95% CI: 0.702-0.853) in the external validation cohort, and the predictive performance was superior to three previously proposed POPF risk score models (all P <0.001, likelihood ratio test).

CONCLUSIONS

A reliable lasso-logistic method was applied to establish a novel nomogram based on six readily available indicators, achieving a sustained, dynamic, and precise POPF prediction for PD patients. With a limited number of variables and easy clinical application, this new model will enable surgeons to proactively predict, identify, and manage pancreatic fistulas to obtain better outcomes from this daunting postoperative complication.

Fatty infiltration of the pancreas: a systematic concept analysis

Fatty infiltration of the pancreas (FIP) has been recognized for nearly a century, yet many aspects of this condition remain unclear. Regular literature reviews on the diagnosis, consequences, and management of FIP are crucial. This review article highlights the various disorders for which FIP has been established as a risk factor, including type 2 diabetes mellitus (T2DM), pancreatitis, pancreatic fistula (PF), metabolic syndrome (MS), polycystic ovary syndrome (PCOS), and pancreatic duct adenocarcinoma (PDAC), as well as the new investigation tools. Given the interdisciplinary nature of FIP research, a broad range of healthcare specialists are involved. This review article covers key aspects of FIP, including nomenclature and definition of pancreatic fat infiltration, history and epidemiology, etiology and pathophysiology, clinical presentation and diagnosis, clinical consequences, and treatment. This review is presented in a detailed narrative format for accessibility to clinicians and medical students.

Pancreatic changes with lifestyle and age: What is normal and what is concerning?

During the aging process, typical morphological changes occur in the pancreas, which leads to a specific "patchy lobular fibrosis in the elderly." The aging process in the pancreas is associated with changes in volume, dimensions, contour, and increasing intrapancreatic fat deposition. Typical changes are seen in ultrasonography, computed tomography, endosonography, and magnetic resonance imaging. Typical age-related changes must be distinguished from lifestyle-related changes. Obesity, high body mass index, and metabolic syndrome also lead to fatty infiltration of the pancreas. In the present article, age-related changes in morphology and imaging are discussed. Particular attention is given to the sonographic verification of fatty infiltration of the pancreas. Ultrasonography is a widely used screening examination method. It is important to acknowledge the features of the normal aging processes and not to interpret them as pathological findings. Reference is made to the uneven fatty infiltration of the pancreas. The differential diagnostic and the differentiation from other processes and diseases leading to fatty infiltration of the pancreas are discussed.

Relationship between preoperative malnutrition, frailty, sarcopenia, body composition, and anthropometry in elderly patients undergoing major pancreatic and biliary surgery

Objective

To analyze the correlation between preoperative nutritional status, frailty, sarcopenia, body composition, and anthropometry in geriatric inpatients undergoing major pancreatic and biliary surgery.

Methods

This is a cross-sectional study of the database from December 2020 to September 2022 in the department of hepatopancreatobiliary surgery, Beijing Hospital. Basal data, anthropometry, and body composition were recorded. NRS 2002, GLIM, FFP 2001, and AWGS 2019 criteria were performed. The incidence, overlap, and correlation of malnutrition, frailty, sarcopenia, and other nutrition-related variables were investigated. Group comparisons were implemented by stratification of age and malignancy. The present study adhered to the STROBE guidelines for cross-sectional study.

Results

A total of 140 consecutive cases were included. The prevalence of nutritional risk, malnutrition, frailty, and sarcopenia was 70.0, 67.1, 20.7, and 36.4%, respectively. The overlaps of malnutrition with sarcopenia, malnutrition with frailty, and sarcopenia with frailty were 36.4, 19.3, and 15.0%. There is a positive correlation between every two of the four diagnostic tools, and all six p-values were below 0.002. Albumin, prealbumin, CC, GS, 6MTW, ASMI, and FFMI showed a significantly negative correlation with the diagnoses of the four tools. Participants with frailty or sarcopenia were significantly more likely to suffer from malnutrition than their control groups with a 5.037 and 3.267 times higher risk, respectively (for frailty, 95% CI: 1.715-14.794, p = 0.003 and for sarcopenia, 95% CI: 2.151-4.963, p<0.001). Summarizing from stratification analysis, most body composition and function variables were worsen in the ≥70 years group than in the younger group, and malignant patients tended to experience more intake reduction and weight loss than the benign group, which affected the nutrition diagnosis.

Conclusion

Elderly inpatients undergoing major pancreatic and biliary surgery possessed high prevalence and overlap rates of malnutrition, frailty, and sarcopenia. Body composition and function deteriorated obviously with aging.

The Impact of CT-Assessed Liver Steatosis on Postoperative Complications After Pancreaticoduodenectomy for Cancer

INTRODUCTION

Liver steatosis (LS) has been increasingly described in preoperative imaging of patients undergoing pancreaticoduodenectomy (PD). The aim of this study was to assess the impact of preoperative LS on complications after PD and identify possible contributors to LS development in this specific cohort.

METHODS

Pancreatic head adenocarcinoma (PDAC) patients scheduled for PD, with preoperative CT-imaging available were included in the study. LS was defined as mean liver density lower than 45 Hounsfield units. Patients showing preoperative LS were matched for patient age, gender, BMI, ASA score, neoadjuvant treatment, and vascular and multivisceral resections, based on propensity scores in a 1:2 ratio to patients with no LS. The primary outcome was postoperative complication severity at 90 days as measured by the comprehensive complication index (CCI) RESULTS: Overall, 247 patients were included in the study. Forty-three (17%) patients presented with LS at preoperative CT-scan. After matching, the LS group included 37 patients, whereas the non-LS group had 74 patients. LS patients had a higher mean (SD) CCI, 29.7 (24.5) versus 19.5 (22.5), p = 0.035, and a longer length of hospital stay, median [IQR] 12 [8-26] versus 8 [7-13] days, p = 0.006 compared with non-LS patients. On multivariate analysis, variables independently associated with CCI were: LS (16% increase, p = 0.048), male sex (19% increase, p = 0.030), ASA score ≥ 3 (26% increase, p = 0.002), fistula risk score (FRS) (28% increase for each point of FRS, p = 0.001) and vascular resection (20% increase, p = 0.019).

CONCLUSION

Preliminary evidence suggests that preoperative LS assessed by CT-scan influences complication severity in patients undergoing PD for PDAC.

Early postoperative risk stratification in patients with pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Early stratification of postoperative pancreatic fistula according to severity and/or need for invasive intervention may improve outcomes after pancreaticoduodenectomy. This study aimed to identify the early postoperative variables that may predict postoperative pancreatic fistula severity.

METHODS

All patients diagnosed with biochemical leak and clinically relevant-postoperative pancreatic fistula based on drain fluid amylase >300 U/L on the fifth postoperative day after pancreaticoduodenectomy were identified from a consecutive cohort from Birmingham, UK. Demographics, intraoperative parameters, and postoperative laboratory results on postoperative days 1 through 7 were retrospectively extracted. Independent predictors of clinically relevant-postoperative pancreatic fistula were identified using multivariable binary logistic regression and converted into a risk score, which was applied to an external cohort from Verona, Italy.

RESULTS

The Birmingham cohort had 187 patients diagnosed with postoperative pancreatic fistula (biochemical leak: 99, clinically relevant: 88). In clinically relevant-postoperative pancreatic fistula patients, the leak became clinically relevant at a median of 9 days (interquartile range: 6-13) after pancreaticoduodenectomy. Male sex (P = .002), drain fluid amylase-postoperative day 3 (P < .001), c-reactive protein postoperative day 3 (P < .001), and albumin-postoperative day 3 (P = .028) were found to be significant predictors of clinically relevant-postoperative pancreatic fistula on multivariable analysis. The multivariable model was converted into a risk score with an area under the receiver operating characteristic curve of 0.78 (standard error: 0.038). This score significantly predicted the need for invasive intervention (postoperative pancreatic fistula grades B3 and C) in the Verona cohort (n = 121; area under the receiver operating characteristic curve: 0.68; standard error = 0.06; P = .006) but did not predict clinically relevant-postoperative pancreatic fistula when grades B1 and B2 were included (area under the receiver operating characteristic curve 0.52; standard error = 0.07; P = .802).

CONCLUSION

We developed a novel risk score based on early postoperative laboratory values that can accurately predict higher grades of clinically relevant-postoperative pancreatic fistula requiring invasive intervention. Early identification of severe postoperative pancreatic fistula may allow earlier intervention.