Exocrine Function Following the Whipple Operation as Assessed by Stool Elastase

Abstract

What impact does pancreaticoduodenectomy (PD) have on exocrine function? Does the pancreatic anastomosis remain patent? When stool elastase became available for testing in November 2001, we began preoperative assessment and then increasingly employed postoperative measurements. From December 2001 until March 2006, 182 patients underwent PD by the same surgeon. Preoperative stool elastase was measured in 138 (76%) patients and was repeated postoperatively at 3 +/- 1 month, 12 +/- 2 months, and 24 +/- 3 months. At the same time periods, an abdominal CT scan was used to assess patency of the pancreatic anastomosis as implied by pancreatic duct dilation in the remnant (dilation = duct >3 mm or, if duct dilated preoperatively, then duct that failed to decrease in size). All cases were reconstructed with duct-to-mucosa pancreaticojejunostomy. Stool elastase was expressed as normal (>200 microg/gram stool), moderately reduced (100-200 microg/gram), or severely reduced (<100 microg/gram). Preoperative stool elastase values were "normal" in 78% (pancreatic cancer 32% normal vs. all other groups >78%; P < or = 0.001). As compared with preoperative values, the percent of cases with reduced elastase levels at 3 months, 1 year, and 2 years postoperatively was 48%, 73%, and 50%, respectively. The CT scans at the time of the 69 stool elastase measurements after PD showed pancreatic duct dilation in the pancreatic remnant in 9 of 69 (9%) stools but was not more frequent in the group with decreased elastase. Based on cases elastase, one third of patients about to have PD will have exocrine insufficiency, an observation most common among the patients with pancreatic cancer (68%). Stool elastase levels are further depressed in the majority of cases after PD from parenchymal loss because we could not implicate an occluded pancreatic anastomosis. These results suggest that, after PD, exocrine supplementation should be given to all patients with pancreatic cancer, especially those with impending adjuvant therapy. To further improve the long-term results after PD, each surgeon should assess the effect of their own type of pancreaticoenteric technique on exocrine function.