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

Abstract

Background: Current endoscopic pancreatic function test (ePFT) methods use either secretin or cholecystokinin (CCK) to measure pancreatic function.

Objective: 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).

Design: Prospective, cross-sectional diagnostic study.

Setting: Single, tertiary-care institution.

Patients: Healthy volunteers and patients evaluated for CP were included.

Interventions: All patients underwent a combined secretin-CCK ePFT. Patients evaluated for CP also underwent EUS during the same endoscopic session.

Main outcome measurements: 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).

Results: 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.

Limitations: Secretin and cholecystokinin endoscopic pancreatic function test (SC ePFT) results were not compared with those of single hormone ePFTs.

Conclusions: The addition of CCK infusion and enzyme concentration measurement to a standard secretin ePFT does not enhance the diagnosis of CP.