A Novel Pancreatic Fistula Risk Score Including Preoperative Radiation Therapy in Pancreatic Cancer Patients

Preoperative ultrasound elastography for postoperative pancreatic fistula prediction after pancreatoduodenectomy: A prospective study

BACKGROUND

Postoperative pancreatic fistulas are the most frequent major complications after pancreatoduodenectomy. The soft pancreatic texture is a critical, independent risk factor for postoperative pancreatic fistulas after pancreatoduodenectomy. The current gold standard for postoperative pancreatic fistula risk evaluation consists of the surgeon's intraoperative palpation of the pancreatic texture and, thus, lacks objectivity. In this prospective study, we used ultrasound-based shear-wave elastography, image data analysis, and a fistula risk score calculator to correlate the stiffness of pancreatic tissue with the occurrence of clinically relevant postoperative pancreatic fistulas.

METHODS

We included 100 patients with pancreatic pathologies (71% pancreatic ductal adenocarcinoma) and 100 healthy individuals who were preoperatively assessed via real-time tissue ultrasound-based shear-wave elastography on a Philips EPIQ 7 ultrasound device and had pancreatic parenchyma histologically evaluated with manually stained images.

RESULTS

We found a significant difference in the mean elasticity between the soft (1.22 m/s) and the hard pancreas group (2.10 m/s; P < .0001). The mean elasticity significantly correlated with the pancreatic fibrosis rate and the appearance of a postoperative pancreatic fistula after pancreatoduodenectomy. Low elasticity (≤1.2 m/s, mean) correlated with soft and high elasticity (>2.0 m/s, mean) with hard pancreatic parenchyma, as assessed by pathologic evaluation. Multivariate analysis revealed a mean elasticity of <1.3 m/s as a significant cut-off predictor for clinically relevant postoperative pancreatic fistulas (P = .003; Youden-Index = 0.6945).

CONCLUSION

Preoperative ultrasound-based shear-wave elastography is a feasible and objective clinical diagnostic modality in evaluating pancreatic tissue stiffness. A mean pancreatic elasticity of <1.3 m/s was a significant independent risk predictor of clinically relevant postoperative pancreatic fistulas after pancreatoduodenectomy.

Risk Models for Developing Pancreatic Fistula After Pancreatoduodenectomy: Validation in a Nationwide Prospective Cohort

OBJECTIVE

To evaluate the performance of published fistula risk models by external validation, and to identify independent risk factors for postoperative pancreatic fistula (POPF).

BACKGROUND

Multiple risk models have been developed to predict POPF after pancreatoduodenectomy. External validation in high-quality prospective cohorts is, however, lacking or only performed for individual models.

METHODS

A post hoc analysis of data from the stepped-wedge cluster cluster-randomized Care After Pancreatic Resection According to an Algorithm for Early Detection and Minimally Invasive Management of Pancreatic Fistula versus Current Practice (PORSCH) trial was performed. Included were all patients undergoing pancreatoduodenectomy in the Netherlands (January 2018-November 2019). Risk models on POPF were identified by a systematic literature search. Model performance was evaluated by calculating the area under the receiver operating curves (AUC) and calibration plots. Multivariable logistic regression was performed to identify independent risk factors associated with clinically relevant POPF.

RESULTS

Overall, 1358 patients undergoing pancreatoduodenectomy were included, of whom 341 patients (25%) developed clinically relevant POPF. Fourteen risk models for POPF were evaluated, with AUCs ranging from 0.62 to 0.70. The updated alternative fistula risk score had an AUC of 0.70 (95% confidence intervals [CI]: 0.69-0.72). The alternative fistula risk score demonstrated an AUC of 0.70 (95% CI: 0.689-0.71), whilst an AUC of 0.70 (95% CI: 0.699-0.71) was also found for the model by Petrova and colleagues. Soft pancreatic texture, pathology other than pancreatic ductal adenocarcinoma or chronic pancreatitis, small pancreatic duct diameter, higher body mass index, minimally invasive resection and male sex were identified as independent predictors of POPF.

CONCLUSION

Published risk models predicting clinically relevant POPF after pancreatoduodenectomy have a moderate predictive accuracy. Their clinical applicability to identify high-risk patients and guide treatment strategies is therefore questionable.

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.

Single Center, Propensity Score Matching Analysis of Different Reconstruction Techniques following Pancreatoduodenectomy

BACKGROUND

Pancreatoduodenectomy is still hampered by significant morbidity. So far, there is no universally accepted technique aimed at minimizing postoperative complications. Herein, we compare three different reconstruction techniques.

METHODS

This is a retrospective study of a prospectively maintained database including 283 patients operated between January 2010 and December 2020. Three reconstruction techniques were compared: (1) the Neuhaus-style telescope pancreatojejunostomy, (2) the pancreatogastrostomy, and (3) the modified Blumgart-style, duct-to-mucosa pancreatojejunostomy. The primary endpoint consisted in determining the rates of clinically relevant postoperative pancreatic fistulas (CR-POPF); the secondary endpoints included 90 days morbidity and mortality rates. A propensity score matching analysis was used.

RESULTS

Rates of CR-POPF did not differ significantly between the groups (Neuhaus-style pancreatojejunostomy 16%, pancreatogastrostomy 17%, modified Blumgart-style pancreatojejunostomy 15%), neither in the unmatched nor in the matched analysis (p = 0.993 and p = 0.901, respectively). Similarly, no significant differences could be observed with regard to major morbidity (unmatched p = 0.596, matched p = 0.188) and mortality rates (unmatched p = 0.371, matched p = 0.209) within the first 90 days following surgery. Propensity-score matching analyses revealed, however, a higher occurrence of post-pancreatectomy hemorrhage after pancreatogastrostomy (p = 0.015).

CONCLUSION

Similar CR-POPF rates suggest no crucial role of the applied reconstruction technique. Increased incidence of intraluminal post-pancreatectomy hemorrhages following pancreatogastrostomy demands awareness for meticulous hemostasis.

Management of postoperative pancreatic fistula after pancreaticoduodenectomy

A postoperative pancreatic fistula (POPF) is the main complication after cephalic pancreaticoduodenectomy (CPD). Unlike its prevention, the curative management of POPFs has long been poorly codified. This review seeks best practices for managing POPFs after CPD. The diagnosis of a POPF is based on two signs: (i) an amylase level in drained fluid more than 3 times the upper limit of the blood amylase level; and (ii) an abnormal clinical course. In the standardised definition of the International Study Group of Pancreatic Surgery, a purely biochemical fistula is no longer counted as a POPF and is treated by gradual withdrawal of the drain over at most 3 weeks. POPF risk can be scored using pre- and intraoperative clinical criteria, many of which are related to the quality of the pancreatic parenchyma and are common to several scoring systems. The prognostic value of these scores can be improved as early as Day 1 by amylase assays in blood and drained fluid. Recent literature, including in particular the Dutch randomised trial PORSCH, argues for early systematic detection of a POPF (periodic assays, CT-scan with injection indicated on standardised clinical and biological criteria plus an opinion from a pancreatic surgeon), for rapid minimally invasive treatment of collections (percutaneous drainage, antibiotic therapy indicated on standardised criteria) to forestall severe septic and/or haemorrhagic forms, and for the swift withdrawal of abdominal drains when the risk of a POPF is theoretically low and evolution is favourable. A haemorrhage occurring after Day 1 always requires CT angiography with arterial time and monitoring in intensive care. Minimally invasive treatment of a POPF (radiologically-guided percutaneous drainage or, more rarely, endoscopic drainage, arterial embolisation) should be preferred as first-line treatment. The addition of artificial nutrition (enteral via a nasogastric or nasojejunal tube, or parenteral) is most often useful. If minimally invasive treatment fails, then reintervention is indicated, preserving the remaining pancreas if possible, but the expected mortality is higher.

Differential Performance of Machine Learning Models in Prediction of Procedure-Specific Outcomes

BACKGROUND

Procedure-specific complications can have devastating consequences. Machine learning-based tools have the potential to outperform traditional statistical modeling in predicting their risk and guiding decision-making. We sought to develop and compare deep neural network (NN) models, a type of machine learning, to logistic regression (LR) for predicting anastomotic leak after colectomy, bile leak after hepatectomy, and pancreatic fistula after pancreaticoduodenectomy (PD).

METHODS

The colectomy, hepatectomy, and PD National Surgical Quality Improvement Program (NSQIP) databases were analyzed. Each dataset was split into training, validation, and testing sets in a 60/20/20 ratio, with fivefold cross-validation. Models were created using NN and LR for each outcome. Models were evaluated primarily with area under the receiver operating characteristic curve (AUROC).

RESULTS

A total of 197,488 patients were included for colectomy, 25,403 for hepatectomy, and 23,333 for PD. For anastomotic leak, AUROC for NN was 0.676 (95% 0.666-0.687), compared with 0.633 (95% CI 0.620-0.647) for LR. For bile leak, AUROC for NN was 0.750 (95% CI 0.739-0.761), compared with 0.722 (95% CI 0.698-0.746) for LR. For pancreatic fistula, AUROC for NN was 0.746 (95% CI 0.733-0.760), compared with 0.713 (95% CI 0.703-0.723) for LR. Variables related to intra-operative information, such as surgical approach, biliary reconstruction, and pancreatic gland texture were highly important for model predictions.

DISCUSSION

Machine learning showed a marginal advantage over traditional statistical techniques in predicting procedure-specific outcomes. However, models that included intra-operative information performed better than those that did not, suggesting that NSQIP procedure-targeted datasets may be strengthened by including relevant intra-operative information.

Risk factors of clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy: A systematic review and meta-analysis

BACKGROUND

Clinically relevant postoperative pancreatic fistula (CR-POPF) is a common and troublesome complication after pancreatoduodenectomy (PD). We conducted a systematic review and meta-analysis to identify the risk factors of CR-POPF after PD.

METHODS

We searched PubMed, EMBASE, and Cochrane Library databases for studies related to risk factors of CR-POPF after PD. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were extracted from the included studies, then a meta-analysis was conducted. If necessary, sensitivity analysis would be performed by changing the effect model or excluding 1 study at a time. Publication bias was assessed by funnel plot and Begg test and Egger test.

RESULTS

A total of 27 studies with 24,740 patients were included, and CR-POPF occurred in 3843 patients (incidence = 17%, 95% CI: 16%-19%). Male (OR = 1.56, 95% CI: 1.42-1.70), body mass index >25 kg/m2 (OR = 1.98, 95% CI: 1.23-3.18), pancreatic duct diameter <3 mm (OR = 1.87, 95% CI: 1.66-2.12), soft pancreatic texture (OR = 3.49, 95% CI: 2.61-4.67), and blood transfusion (OR = 3.10, 95% CI: 2.01-4.77) can significantly increase the risk of CR-POPF. Pancreatic adenocarcinoma (OR = 0.54, 95% CI: 0.47-0.61), vascular resection (OR = 0.57, 95% CI: 0.39-0.83), and preoperative chemoradiotherapy (OR = 0.68, 95% CI: 0.57-0.81) can significantly decrease the factor of CR-POPF. Diabetes mellitus was not statistically associated with CR-POPF (OR = 0.66, 95% CI: 0.40-1.08). However, the analysis of body mass index, pancreatic texture, and diabetes mellitus had a high heterogeneity, then sensitivity analysis was performed, and the result after sensitivity analysis showed diabetes mellitus can significantly decrease the risk of CR-POPF. There was no significant publication bias in this meta-analysis.

CONCLUSIONS

The current review assessed the effects of different factors on CR-POPF. This can provide a basis for the prevention and management of CR-POPF. Effective interventions targeting the above risk factors should be investigated in future studies for decreasing the occurrence of CR-POPF.

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.

Neoadjuvant Therapy Is Associated with Improved Chemotherapy Delivery and Overall Survival Compared to Upfront Resection in Pancreatic Cancer without Increasing Perioperative Complications

The role of neoadjuvant chemoradiotherapy and/or chemotherapy (neoCHT) in patients with pancreatic ductal adenocarcinoma (PDAC) is poorly defined. We hypothesized that patients who underwent neoadjuvant therapy (NAT) would have improved systemic therapy delivery, as well as comparable perioperative complications, compared to patients undergoing upfront resection. This is an IRB-approved retrospective study of potentially resectable PDAC patients treated within an academic quaternary referral center between 2011 and 2018. Data were abstracted from the electronic medical record using an institutional cancer registry and the National Surgical Quality Improvement Program. Three hundred and fourteen patients were eligible for analysis and eighty-one patients received NAT. The median overall survival (OS) was significantly improved in patients who received NAT (28.6 vs. 20.1 months, p = 0.014). Patients receiving neoCHT had an overall increased mean duration of systemic therapy (p < 0.001), and the median OS improved with each month of chemotherapy delivered (HR = 0.81 per month CHT, 95% CI (0.76-0.86), p < 0.001). NAT was not associated with increases in early severe post-operative complications (p = 0.47), late leaks (p = 0.23), or 30-90 day readmissions (p = 0.084). Our results show improved OS in patients who received NAT, driven largely by improved chemotherapy delivery, without an apparent increase in early or late perioperative complications compared to patients undergoing upfront resection.

The role of acinar content at pancreatic resection margin in the development of postoperative pancreatic fistula and acute pancreatitis after pancreaticoduodenectomy

BACKGROUND

A fatty infiltration of the pancreas has been traditionally regarded as the main histological risk factor for postoperative pancreatic fistula, whereas the role of the secreting acinar compartment has been poorly investigated. The aim of this study was to evaluate the role of acinar content at pancreatic resection margin in the development of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis after pancreaticoduodenectomy.

METHODS

Data from 388 consecutive patients who underwent pancreaticoduodenectomy (2018-2019) were analyzed. Pancreatic section margins were histologically assessed for acinar, fibrosis, and fat content. Acinar content was categorized using median and third quartile as cut-offs. Univariate and multivariable analysis of possible predictors of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis were performed.

RESULTS

Acinar content was <60% in 166 patients (42.8%), ≥60% and ≤80% in 156 patients (40.2%), and >80% in 66 patients (17.0%). The rate of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis was significantly higher in patients with acinar content >80% (39.4% and 33.3%, respectively) as well as in those with acinar content ≥60% and ≤80% (36.5% and 35.3%, respectively), compared with patients with acinar content <60% (10.2% and 5.4%, respectively) (P < .001). Acinar content was identified as an independent predictor of clinically relevant postoperative pancreatic fistula (≥60% and ≤80%, odds ratio 2.51, P = .008; >80%, odds ratio 2.93, P = .010) and clinically relevant postoperative acute pancreatitis (≥60% and ≤80%, odds ratio 9.42, P < .001; >80%, odds ratio 10.16, P < .001).

CONCLUSION

An acinar content at pancreatic resection margin ≥60% is associated to an increased risk of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis. Fat content was associated neither with clinically relevant postoperative pancreatic fistula nor with clinically relevant postoperative acute pancreatitis.