Prediction of pancreatic anastomotic failure after pancreatic head resection using preoperative diffusion-weighted MR imaging

Use of gadoxetic acid-enhanced MRI to predict the development of postoperative pancreatic fistulas by estimating the degree of pancreatic fibrosis

BACKGROUND

Postoperative pancreatic fistula (POPF) can be life-threatening, and gadoxetic acid-enhanced MRI is routinely performed in patients undergoing pancreatic surgery. However, previous reports have not investigated if gadoxetic acid-enhanced MRI can be used to predict POPF risk.

OBJECTIVE

This study aims to explore if gadoxetic acid-enhanced MRI can predict pancreatic fibrosis and the need for POPF treatment before surgery.

METHOD

We retrospectively analyzed gadoxetic acid-enhanced MR images from 142 patients who underwent pancreatic surgery between January 1, 2011, and April 30, 2018. Pre-dynamic signal intensity (SI) and values for portal, transitional, and hepatobiliary phase standardized based on pre-dynamic study values were analyzed. The diameter of the main pancreatic duct (DMPD) was measured, and the degree of pancreatic fibrosis was classified as F0-F3. We defined POPF higher than grade B as significant.

RESULTS

Odds ratios for combinations that led to any degree of fibrosis higher than grade B were defined as significant risk factors. The highest odds ratio was obtained for F0 vs. F1-F3 (p = 0.038). DMPD (p < 0.001), pre-SI (p = 0.008), portal-SI/pre-SI (p < 0.001), transitional-SI/pre-SI (p < 0.001), and hepatobiliary-SI/pre-SI (p = 0.012) were significantly correlated with the presence of fibrosis. The presence of fibrosis was best detected by DMPD (AUC = 0.777). Individual specificity values of transitional-SI/pre-SI and DMPD were 95.5% and 86.6%, respectively, and their combined specificity was 97.7%.

CONCLUSION

The absence of pancreatic fibrosis is a risk factor for developing POPF higher than grade B. DMPD was the most useful diagnostic indicator of the presence of fibrosis among our analysis, and its specificity increased when combined with transitional-SI/pre-SI.

[Predictors of external pancreatic fistulae after pancreatic resection]

Despite a significant decrease in postoperative mortality after pancreatic resections in recent years (5.2-15% after pancreatoduodenectomy and about 5% after distal pancreatectomy), incidence of postoperative complications remains high (30-50% and 22-50%, respectively). Postoperative pancreatic fistula is one of the most common and formidable complications. Currently, most authors use the classification proposed by the International Study Group for Pancreatic Fistula (biochemical failure, fistula type B and C). Prediction of the risk of postoperative fistula is still a complex and unresolved problem of modern surgical pancreatology. According to the literature, the main risk factors of postoperative pancreatic fistulae are obesity and high body mass index, concomitant cardiovascular diseases, no neoadjuvant chemo- and radiotherapy, soft pancreatic texture, narrow pancreatic duct, no fibrotic changes in parenchyma, adipose infiltration of the pancreas, advanced intraoperative blood loss, as well as center experience. Most often, magnetic resonance imaging, computed tomography, ultrasound elastography and various multivariate risk assessment systems are used to estimate the risk of pancreatic fistulae. However, a generally accepted technique does not exist. This manuscript is devoted to analysis of risk factors of postoperative pancreatic fistulae and diagnostic methods for assessment of this risk.

Risk of pancreatitis after pancreatic duct guidewire placement during endoscopic retrograde cholangiopancreatography

BACKGROUND & AIMS

Advanced techniques have been developed to overcome difficult cannulation cases in endoscopic retrograde cholangiopancreatography (ERCP). Pancreatic duct guidewire placement method (PGW) is performed in difficult cannulation cases; it is possible that it places patients at risk of post-ERCP pancreatitis (PEP). The mechanism of PEP is still unclear, but pancreatic duct pressure and injury of pancreatic duct are known causes of PEP. Therefore, we hypothesized a relationship between pancreatic duct diameter and PEP and predicted that PGW would increase the risk of PEP in patients with non-dilated pancreatic ducts. This study aimed to investigate whether PGW increased the risk of PEP in patients with pancreatic duct diameter ≤ 3 mm.

METHODS

We analyzed 332 patients with pancreatic duct ≤ 3 mm who performed first time ERCP session. The primary endpoint was the rate of adverse event of PEP. We evaluated the risk of PEP in patients who had undergone PGW compared to those who had not, using the inverse probability of treatment weighting (IPTW) analysis.

RESULTS

PGW was found to be an independent risk factor for PEP by univariate analysis (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.12-5.38; p = 0.03) after IPTW in patients with pancreatic duct diameter ≤ 3 mm. Adjusted for all covariates, PGW remained an independent risk factor for PEP (OR, 3.12; 95% CI, 1.33-7.33; p = 0.01).

CONCLUSION

Our results indicate that PGW in patients with pancreatic duct diameter ≤ 3 mm increases the risk of PEP.