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

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Endocrine function; Exocrine function; Exocrine insufficiency; PD; PG; Pancreatojejunostomy.