Introduction: What impact does distal pancreatectomy have on pancreatic exocrine function? With the recent ability to measure human stool elastase-1 (HSE-1), the evaluation of exocrine insufficiency has become less complex and has a negative predictive value of almost 100%. Our studies have suggested that pancreatic insufficiency after pancreaticoduodenectomy is caused by exocrine atrophy from pancreatic cancer and/or parenchymal loss from resection. Our objective was to use HSE-1 to determine exocrine function after distal pancreatectomy (DP) - this has not previously been studied.
Methods: During a 65 month period (July 2002 - November 2007), 100 patients underwent DP by the same surgeon. The pathologic tissue diagnosis and the amount of pancreas resected were recorded. Extent of resection was divided into two categories, those limited to the left of the portal vein (PV) and those extending to the PV or further. HSE-1 values were measured preoperatively in 68 patients and repeated at 3 + 2 months, 12 + 3 months, and 24 + 6 months in 39, 19, and 9 patients, respectively. HSE-1 was expressed as abnormal at <200 µg/g stool.
Results: Preoperative HSE-1 values were abnormal in 19% of patients prior to undergoing DP (67% if chronic pancreatitis, 38% if pancreatic adenocarcinoma, and 11% in all other diseases; p<0.001). Postoperative HSE-1 levels were then compared by the amount of pancreas resected. At three months after resection, HSE-1 was normal or became normal in all patients if resection was limited to the left of the PV, but in just 79% if resection extended to the PV (p=0.03). At 12 months, normal HSE-1 was observed in 100% of patients if the resection was to the left of the PV and 88% if resection extended to the PV (p=0.2). At 24 months, our limited results showed normal function in 100% of patients if the resection was to the left of the PV and 75% if resection extended to the PV (p=0.2). In the subgroup with normal preoperative HSE-1 (81% of patients) whose resection was limited to the left of the PV, 100% had normal exocrine function at all timepoints. If the resection extended to the PV, 82% had normal exocrine function at three months (p=0.09), while 100% had normal exocrine function at 12 and 24 months.
Conclusion: Of patients undergoing DP, one-fifth will have pancreatic insufficiency, most commonly those with pancreatic adenocarcinoma or chronic pancreatitis. Postoperative pancreatic insufficiency was seen only in those with resection that extended to the PV or beyond, and was transient. Exocrine insufficiency before and after DP is related to both the disease and the extent of resection, and can improve with time.