SHORT METAL VERSUS PLASTIC STENTS FOR MALIGNANT OBSTRUCTIVE JAUNDICE PRIOR TO POSSIBLE WHIPPLEʼS OPERATION

Abstract

Purpose: Relief of malignant obstructive jaundice can be endoscopically achieved with plastic or metal biliary stenting. Plastic stents are cheaper but have shorter patency. Short biliary Wallstents do not preclude subsequent Whipple. We analyzed costs and outcomes to better define the role of different stents in the management of obstructive jaundice from pancreatic cancer in patients in whom operative status is initially uncertain at the time of ERCP. Methods: A Markov model was constructed to evaluate expected costs and outcomes associated with biliary stenting via ERCP in patients with malignant obstructive jaundice. Strategies evaluated were: 1) initial plastic stent followed by plastic stents for subsequent occlusions in non-operative candidates after staging (Plastic f/u Plastic), 2) initial plastic subsequent metal Wallstent (Plastic f/u Metal), 3) initial short metal subsequent plastic (Metal f/u Plastic) and 4) initial short metal stent subsequent metal Wallstent (Metal f/u Metal). Stent occlusion rates, ERCP complication rates and outcomes, cholangitis rates and outcomes with stent occlusions, pancreatic cancer mortality rates and Whipple rates utilized in the model were derived from medical literature. Costs of associated outcomes were based on 2004 Medicare standard allowable charges. Costs and health outcomes were accrued until all the patients reached an absorbing health state (death or Whipple's surgery that eliminates further need for palliative biliary stenting) or 24-cycles (months) ended. Results: Monte Carlo simulation resulted in the following average costs in decreasing cost-minimizing optimality: 1) Metal f/u Metal $19,935,2) Plastic f/u Metal $20,157, 3) Metal f/u Plastic $20,871 4) Plastic f/u Plastic $20,878. For initial plastic stents to be preferred over short metal shorts, at least 70% of patients would need to be potentially resectable for Whipple operation. If a patient's life expectancy is less than 5-months, subsequent plastic stents become preferred. Additional sensitivity analyses showed unchanged results over acceptable ranges. Conclusions: This decision analysis identifies initial short metal stents via ERCP prior to definitive cancer staging as the preferred initial cost-minimizing strategy. If the patient is not a good operative candidate or has advanced disease, metal Wallstents to treat subsequent occlusions offer the lowest associated costs.