Is the remnant pancreas still working over a year after surgery in patients undergoing pancreaticoduodenectomy with reconstruction by pancreaticogastrostomy?

Pancreaticogastrostomy (PG) has been widely used as an alternative to pancreatojejunostomy (PJ) in patients undergoing pancreaticoduodenectomy (PD), but its long-term exocrine function remains unclear. The present study aimed to measure the secretion of pancreatic α-amylase (p-AMY) into the gastric cavity in patients who underwent PG reconstruction after PD over 1 year after surgery and to evaluate the relationship between gastric p-AMY level and clinically available indirect tests.Clinical records of 39 patients who underwent PG reconstruction after PD were reviewed. Pancreatic exocrine function was evaluated over 1 year after surgery using the following methods: 1) Measurement of p-AMY level in gastric fluids (gastric p-AMY level) during routine gastrointestinal endoscopy, 2) Qualitative faecal fat determination by Sudan III staining on faeces and 3) Pancreatic function diagnostic (PFD) test using oral administration of N-benzoyl-l-tyrosyl-p-aminobenzoic acid.Gastric p-AMY level was detectable in 31 of 39 patients (79%), and 12 patients (30.8%) had steatorrhea over a year after surgery. Patients with steatorrhea had significantly lower gastric p-AMY level, larger diameter of remnant main pancreatic duct (MPD) and larger pancreatic duct to parenchymal thickness ratio than those without steatorrhea (84 IU/L vs 7979 IU/L, respectively; P < 0.001, 5.3 mm vs 3.2 mm, respectively; P = 0.001, and 0.38 vs 0.23, respectively; P = 0.007). Receiver operating characteristic analysis showed that the cut-off value of the diameter of the remnant MPD to predict steatorrhea was 3.5 mm (sensitivity, 92.3%; specificity, 70.4%). PFD test was not associated with any clinical data.Pancreatic enzyme was detected in 79% of patients having PG reconstruction. Diameter of remnant MPD >3.5 mm and pancreatic parenchymal atrophy may be surrogate markers of postoperative exocrine insufficiency following PD.