Background: Pylorus preserving pancreatico-duodenectomy (PPPD) is preferred over pancreatico-duodenectomy (classical Whipple) as surgical procedure for (peri) ampullary cancer or chronic pancreatitis. Despite preservation of the stomach, PPPD may negatively influence gastrointestinal function by delaying gastric emptying. Little is known however about gastric acid secretion after PPPD. We hypothesize that acid secretion is increased after PPPD, because of loss of duodenal negative feed back. This may result in a more acidic intestinal environment and negatively influence the efficacy of pancreatic enzyme therapy.
Methods: To test this hypothesis we have performed 24 hour ambulatory continuous intragastric and intraintestinal pH measurements in 15 patients after PPPD (age 46-78 years, 9M, 6F; chronic pancreatitis n=6, ampullary carcinoma n=9) and in 9 healthy controls (age 20-54 years, 5M, 4F). Catheters for pH metry were positioned 10 cm distal of the LES (stomach) and 15-20 cm distal of the pylorus (proximal small bowel). Meal ingestion, meal composition and supine periods were standardized. Pancreatic function was evaluated by urinary PABA recovery.
Results: (medians and interquartile ranges). Median 24 h intragastric pH was not different between PPPD (1.7; 1.6- 2.1) and control (1.7, 1.5-2.0). Although post-dinner 2h intragastric pH was lower in PPPD (2.5; 1.7-4.1) compared to control (3.1; 2.4-3.7) the difference was not statistically significant. Exocrine function was significantly (p<0.01) impaired after PPPD:PABA recovery 29± 5% versus 64± 2% (controls). In the PPPD group median postprandial intragastric pH was related to exocrine pancreatic function (R=0.575; p=0.04). Median 24 h intestinal pH was not reduced in PPPD, but on the other hand even significantly (p<0.05) increased (6.3; 6.0-6.5) compared to controls (6.0; 5.9-6.1) No differences in intragastric or intraduodenal pH were observed between PPPD patients operated for cancer or chronic pancreatitis.
Conclusions: Intragastric pH in patients after PPPD is not different from controls and median intestinal pH is even significantly increased. Thus, gastrointestinal pH does not negatively influence efficacy of enzyme substitution after PPPD.