Complications of chronic pancreatitis prior to and following surgical treatment: A proposal for classification

Abstract

Background: Chronic pancreatitis (CP) is a long-lasting disease frequently associated with complications for which there is no comprehensive pathophysiological classification.

Aim: The aims of this study were to: Propose a pathophysiological classification of the complications of CP; evaluate their prevalence in a surgical cohort prior to, and following surgical management; and assess the impact of the surgical treatment on the occurrence of new complications of CP during follow-up. We hypothesized that optimal surgical treatment can resolve existing complications and reduce the risk of new complications, with the exclusion of pancreatic insufficiency. The primary outcomes were prevalence of complications of CP at baseline (prior to surgical treatment) and occurrence of new complications during follow-up.

Methods: After institutional review board approval, a prospective observational cohort study with long-term follow-up (up to 20.4 years) was conducted. All consecutive single-center adult patients (≥ 18 years of age) with CP according to the criteria of the American Pancreas Association subjected to surgical management between 1997 and 2021, were included. The prevalence of CP complications evaluated, according to the proposed classification, in a surgical cohort of 166 patients. Development of the pathophysiological classification was based on a literature review on the clinical presentation, course, and complications of CP, as well a review of previous classification systems of CP.

Results: We distinguished four groups of complications: Pancreatic duct complications, peripancreatic complications, pancreatic hemorrhages, and pancreatic insufficiency (exocrine and endocrine). Their baseline prevalence was 20.5%, 23.5%, 10.2%, 31.3%, and 27.1%, respectively. Surgical treatment was highly effective in avoiding new complications in the first and third groups. In the group of peripancreatic complications, the 15-year Kaplan-Meier prevalence of new complications was 12.1%. The prevalence of pancreatic exocrine and endocrine insufficiency increased during follow-up, being 66.4% and 47.1%, respectively, at 15 years following surgery. Pancreatoduodenal resection resulted optimal results in avoiding new peripancreatic complications, but was associated with the highest rate of pancreatic exocrine insufficiency.

Conclusion: The proposed complication classification improves the understanding of CP. It could be beneficial for clinical decision making, as it provides an opportunity for more comprehensive judgement on patient's needs on the one hand, and on the pros and cons of the treatment under consideration, on the other. The presence of complications of CP and the risk of development of new ones should be among the main determinants of surgical choice.

Keywords: Chronic pancreatitis; Classification; Complications; Pathophysiology; Surgical treatment.

Figure 1

Pathophysiological classification of complications of chronic pancreatitis. ¹References to the rates of prevalence. PEI: Pancreatic exocrine insufficiency; T3cDM: Type 3c diabetes mellitus.

Figure 2

Main complications of chronic pancreatitis. (1) Pancreatic duct complications: 1-A: Pancreatic pseudocyst; 1-B: Pancreatic ascites; 1-C: Pancreatic pleural effusion; (2) Peripancreatic complications: 2-A: Common bile duct stenosis; 2-B: Duodenal stenosis; 2-C: Venous thrombosis (splenic vein); 2-D: Left-side portal hypertension due to splenic vein thrombosis; (3) Pancreatic hemorrhages: 3-A: Peripancreatic pseudoaneurysm; 3-B: Ruptured pseudoaneurysm (into pancreatic duct–hemosuccus pancreaticus); and (4) Pancreatic exocrine and endocrine insufficiency due to extensive loss of functional pancreatic parenchyma (acinar atrophy, fibrosis, inflammatory infiltrates).

Figure 3

Kaplan-Meier curves of complication-free survival of pathophysiologically grouped complications prior to, and following surgical management of chronic pancreatitis in a cohort of 166 patients.

Figure 4

Kaplan-Meier curves of complication-free survival characterizing the impact of the type of surgery on occurrence of the new complications of chronic pancreatitis. The log-rank test was used to assess differences between the curves. A: Peripancreatic complications (Whipple’s pancreatoduodenal resection–red line, other pancreatic resections–blue line, pancreatic drainage operations–green line); B: Pancreatic exocrine insufficiency (Whipple’s pancreatoduodenal resection–red line, other pancreatic resections–blue line, pancreatic drainage operations–green line); C: Pancreatic endocrine insufficiency (pancreatic distal resection–orange line, other pancreatic resections–blue line, pancreatic drainage operations–green line).