Outpatient Drainmanagement of patients with clinically relevant Postoperative Pancreatic Fistula (POPF)

Portable droplet-based real-time monitoring of pancreatic α-amylase in postoperative patients

Postoperative complications after pancreatic surgery are frequent and can be life-threatening. Current clinical diagnostic strategies involve time-consuming quantification of α-amylase activity in abdominal drain fluid, which is performed on the first and third postoperative day. The lack of real-time monitoring may delay adjustment of medical treatment upon complications and worsen prognosis for patients. We report a bedside portable droplet-based millifluidic device enabling real-time sensing of drain α-amylase activity for postoperative monitoring of patients undergoing pancreatic surgery. Here, a tiny amount of drain liquid of patient samples is continuously collected and co-encapsulated with a starch reagent in nanoliter-sized droplets to track the fluorescence intensity released upon reaction with α-amylase. Comparing the α-amylase levels of 32 patients, 97 % of the results of the droplet-based millifluidic system matched the clinical data. Our method reduces the α-amylase assay duration to approximately 3 min with the limit of detection 7 nmol/s·L, enabling amylase activity monitoring at the bedside in clinical real-time. The presented droplet-based platform can be extended for analysis of different body fluids, diseases, and towards a broader range of biomarkers, including lipase, bilirubin, lactate, inflammation, or liquid biopsy markers, paving the way towards new standards in postoperative patient monitoring.

Preoperative ultrasound radiomics for predicting clinically relevant postoperative pancreatic fistula after pancreatectomy

OBJECTIVES

To evaluate the efficacy of the radiomics model based on preoperative B-mode ultrasound (BMUS) and shear wave elastography (SWE) for predicting the occurrence of clinically relevant-postoperative pancreatic fistula (CR-POPF).

METHODS

Patients who were scheduled to undergo pancreatectomy were prospectively enrolled and received ultrasound assessment within one week before surgery. The risk factors of POPF (grades B and grades C) were analyzed. Preoperative BMUS images, SWE values of pancreatic lesions and surrounding parenchyma were used to build preoperative prediction radiomics models. Radiomic signatures were extracted and constructed using a minimal Redundancy Maximal Relevance (mRMR) algorithm and an L1 penalized logistic regression. A combined model was built using multivariate regression which incorporated radiomics signatures and clinical data.

RESULTS

From January 2020 to November 2021, a total of 147 patients (85 distal pancreatectomies and 62 pancreaticoduodenectomies) were enrolled. During the three-week follow-up after pancreatectomy, the incidence rates of grade B/C POPF were 28.6% (42/147). Radiomic signatures constructed from BMUS of pancreas parenchymal regions (panRS) achieved an area under the receiver operating characteristic curve (AUC) of 0.75, accuracy of 68.7%, sensitivity of 85.7 %, and specificity of 61.9 % in preoperative noninvasive prediction of CR-POPF. The AUC of the radiomics model increased to 0.81 when panRS was used for the prediction of CR-POPF after pancreaticoduodenectomy.

CONCLUSIONS

Radiomics model based on ultrasound images was potentially useful for predicting CR-POPF. Patients with high-risk factors should be closely monitored when postoperation.

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.

Predicting postoperative pancreatic fistula in pancreatic head resections: which score fits all?

Purpose

Postoperative pancreatic fistula (POPF) is a major complication of pancreatic surgery and can be fatal. Better stratification of patients into risk groups may help to select those who might benefit from strategies to prevent complications. The aim of this study was to validate ten prognostic scores in patients who underwent pancreatic head surgery.

Methods

A total of 364 patients were included in this study between September 2012 and August 2017. Ten risk scores were applied to this cohort. Univariate and multivariate analyses were performed considering all risk factors in the scores. Furthermore, the stratification of patients into risk categories was statistically tested.

Results

Nine of the scores (Ansorge et al., Braga et al., Callery et al., Graham et al., Kantor et al., Mungroop et al., Roberts et al., Yamamoto et al. and Wellner et al.) showed strong prognostic stratification for developing POPF (p < 0.001). There was no significant prognostic value for the Fujiwara et al. risk score. Histology, pancreatic duct diameter, intraabdominal fat thickness in computed tomography findings, body mass index, and C-reactive protein were independent prognostic factors on multivariate analysis.

Conclusion

Most risk scores tend to stratify patients correctly according to risk for POPF. Nevertheless, except for the fistula risk score (Callery et al.) and its alternative version (Mungroop et al.), many of the published risk scores are obscure even for the dedicated pancreatic surgeon in terms of their clinical practicability. There is a need for future studies to provide strategies for preventing POPF and managing patients with high-risk stigmata.