The Result of Japanese Multicenter, Randomized Trial of Endoscopic Stenting for the Nonresectable Pancreatic Head Cancer (JM-Test) Retrospective Investigation

Abstract

Background and Aim: Both DoubleLayer® stent (DLS) and Covered Wallstent® (CWS) are effective for management of malignant distal biliary obstructions, previously reported. DLS has tannenbaum type structure constructed 3 layers; perfluoro alkoxy (inner), polyamid elstmar (outer) sandwiched wire mesh layer. We estimated efficacy and safety of DLS compared with CWS in the patient with pancreas head cancer (PHC). Patients and Methods: Between May 2005 and April 2007, we enrolled 120 unresectable PHC with distal biliary obstructions. They were randomly assigned to DLS or CWS placement and observe at least 6 months. Results: we excluded 6 failed cases with digestive obstruction and 9 cases with imperfect data and follow up, finally we estimated 105 cases (53 DLS, 52 CWS). There are still alive cases; 10 in DLS (5 with patent stent) and 11 in CWS (8 with patent stent). There was no significantly difference in patient survival between 2 groups. The cumulative stent patency in CWS was significantly higher than that of DLS group (p=0.026). Median survival and stent patency were 250 and 130 days in DLS, and 215 and 419 days in CWS. Stent occlusion occurred in 31 (58.5%) after a median of 110 days in DLS group, and in 18 patients (34.6%) after a median of 144 days in CWS group. The incidence of DLS occlusion was significantly higher than that of CWS (p = 0.0190). The causes of occlusions were tumor overgrowth (0, 2), ingrowth (0, 2), sludge (24, 3), food impaction (1, 3) and kinking bile duct (2, 0). Other complications were pancreatitis (0, 1), cholecystitis (0, 4), migrations (0, 4), liver abscess (2, 0) and other (1, 2). There was no significantly difference in the incidence of complications between 2 groups. Conclusion: DLS did not show longer patency to CWS in the patients with pancreas cancer. Cholecystitis and migration were still unresolved complications in CWS, but the incidence did not significantly differed from DLS.