Endoscopic pancreatic function test using combined secretin and cholecystokinin stimulation for the evaluation of chronic pancreatitis

Abstract

Current endoscopic pancreatic function test (ePFT) methods use either secretin or cholecystokinin (CCK) to measure pancreatic function. To evaluate a novel ePFT protocol that includes both secretin and CCK stimulation and to assess which fluid parameters best discriminate patients with chronic pancreatitis (CP). Prospective, cross-sectional diagnostic study. Single, tertiary-care institution. Healthy volunteers and patients evaluated for CP were included. All patients underwent a combined secretin-CCK ePFT. Patients evaluated for CP also underwent EUS during the same endoscopic session. Duodenal fluid bicarbonate, lipase, and amylase concentrations were measured after CCK and secretin stimulation. Results were compared based on the presence of CP detected by EUS (≥5 features). Twenty healthy volunteers and 69 patients evaluated for CP completed the secretin and CCK ePFT. Patients with an EUS score of 5 or higher had significantly decreased peak bicarbonate concentrations (72 mmol) compared with patients with an EUS score lower than 5 (90 mmol) and healthy subjects (108 mmol) (P < .001). Peak concentrations of amylase and lipase and total fluid volume were not significantly different between patients with CP and controls. Receiver-operating characteristic analysis revealed that peak bicarbonate concentration had superior discrimination for CP (area under the curve [AUC] 0.738) compared with peak amylase (AUC 0.677) and peak lipase (AUC 0.627). The addition of enzyme concentration measurement did not improve discrimination compared with peak bicarbonate alone. Secretin and cholecystokinin endoscopic pancreatic function test (SC ePFT) results were not compared with those of single hormone ePFTs. The addition of CCK infusion and enzyme concentration measurement to a standard secretin ePFT does not enhance the diagnosis of CP.