John J. Bosco

A prospective, randomized, controlled trial of covered expandable metal stents in the palliation of malignant esophageal obstruction at the gastroesophageal junction

OBJECTIVE:Palliation of malignant esophageal obstruction is an important clinical problem. Expandable metal stents are a major advance in therapy, but many stents become obstructed because of tumor ingrowth. The aim of this study was to compare a new, membrane-covered expandable metal stent to conventional prostheses in a randomized controlled trial.METHODS:Sixty-two patients with malignant inoperable esophageal obstruction at the gastroesophageal junction participated in the study. Patients were randomly assigned to covered or uncovered stents. The principal outcome measure was the need for reintervention because of recurrent dysphagia or migration. Secondary endpoints were relief of dysphagia measured by a dysphagia score (grade 0 = no dysphagia, grade 1 = able to eat solid food, grade 2 = semisolids only, grade 3 = liquids only, grade 4 = complete dysphagia) and the rate of complications and functional status. All patients were observed at monthly intervals until death or for 6 months.RESULTS:One week after stenting the dysphagia score improved significantly in both the uncovered (n = 32, 3 ± 0.1 to 1 ± 0.1 [means ± SEMs], p < 0.001) and covered (n = 30, 3 ± 0.1 to 1 ± 0.2 [means ± SEMs], p < 0.001) stents. Obstructing tumor ingrowth was significantly more likely in the uncovered stent group (9/30) than in the covered group (1/32) (p = 0.005). Significant stent migration occurred in 2/30 patients with uncovered stents, as compared with 4/32 patients in the covered group (p = 0.44). Reinterventions for tumor ingrowth were significantly greater in the uncovered stent group (27%), as compared with 0% in the covered group (p = 0.002). Life table analysis showed similar survival in both groups.CONCLUSION:Membrane-covered stents have significantly better palliation than conventional bare metal stents because of decreased rates of tumor ingrowth that necessitate endoscopic reintervention for dysphagia.

Endoscopic needle aspiration biopsy at ERCP in the diagnosis of biliary strictures.

We have developed a ball-tipped catheter with a retractable 22-gauge, 7-mm long needle to perform endoscopic needle aspiration (ENA) for cytology and compared this technique to brush cytology of malignant-appearing biliary strictures during ERCP. Of 31 patients, 26 had proven malignant strictures involving the common bile duct and 5 had benign lesions. All 31 patients had ENA and 29 were brushed. Positive ENAs were obtained in 16 of 26 patients (61.5%) and positive brushings in 2 of 24 (8.3%). With the addition of two suspicious ENAs for pancreatic adenocarcinoma, 73% of patients had positive or suspicious cytology for malignancy by combined ENA and brush with a specificity of 100%. Although ENA appeared to be more sensitive in diagnosing cholangiocarcinoma, it proved to be most effective in the diagnosis of pancreatic adenocarcinoma when compared with brush cytology. One patient with cholangiocarcinoma in our series was diagnosed by brush cytology only, with a negative ENA, supporting our recommendation of using both endoscopic brushings and ENA for cytology when evaluating biliary strictures.

Management of occluded biliary Wallstents

Background—Wallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion. Aims—To evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion. Methods—A multicentre retrospective study of patients managed for a biliary Wallstent occlusion. Results—Data were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30–1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5–34.3) to 2.1 (0.2–27.7) mg/100 ml (p<0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22–118), 98 days (54–142), and 34 days (30–380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option. Conclusion—Although all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.

Endoscopic Sphincterotomy for Stones By Experts Is Safe, Even in Younger Patients With Normal Ducts

OBJECTIVE To provide current information on the risks of endoscopic sphincterotomy for stone. SUMMARY BACKGROUND DATA In recent years (since the popularity of laparoscopic cholecystectomy), endoscopic sphincterotomy has been used increasingly for the management of bile duct stones in relatively young and healthy patients. The validity of this trend has been questioned using data on short-term complications derived from earlier decades that involved more elderly and high-risk patients. METHODS Seven academic centers collected data prospectively using a common database. Complications within 30 days of the procedures were documented by standard criteria. RESULTS Of 1921 patients, 112 (5.8%) developed complications; two thirds of these events were graded as mild (<3 days in hospital). There was no evidence of increased risk in younger patients or in those with smaller bile ducts. There was only one severe complication and there were no fatalities in 238 patients age <60, with bile duct diameters of <9 mm. CONCLUSION Sphincterotomy for stones can be performed very safely by experienced endoscopists.

Endoscopic needle localization of pancreatic pseudocysts before transmural drainage

(biliary stents) for improved drainage. Radiology 1983;148:8994. 14. Dooley JS, Dick R, George P, et al. Percutaneous transhepatic endoprosthesis for bile duct obstruction: complications and results. Gastroenterology 1984;86:905-9. 15. Mueller PR, Ferrucci JT, Teplick SK, et al. Biliary stent endoprosthesis: analysis of complications in 113 patients. Radiology 1985;156:637-9. 16. Lammer J, Neumayer K. Biliary drainage endoprostheses: experience with 201 placements. Radiology 1986;159:625-9. 17. Deviere J, Baize M, de Toeuf J, Cremer M. Long-term follow-up of patients with hilar malignant stricture treated by endoscopic internal drainage. Gastrointest Endosc 1988;34:95-6. 18. Motte S, Deviere J, Dumenceau JM, Serruys E, Thys JP, Cremer M. Risk factors for septicemia following endoscopic biliary stenting. Gastroenterology 1991;101:1374-81. 19. Coons HG. Self-expanding stainless steel biliary stents. Radiology 1989;170:979-83.

Multicenter randomized trial of the spiral Z-stent compared with the Wallstent for malignant biliary obstruction.

BACKGROUND The industry standard since 1990 for self-expanding biliary metallic stents has been the Wallstent. In 1998 the Spiral Z-stent was released. This randomized trial compared the Z-stent with the Wallstent in the treatment of malignant biliary obstruction. METHODS Patients with unresectable malignant biliary obstruction distal to the bile duct bifurcation were randomized to receive a 10-mm diameter Wallstent or a 10-mm diameter Z-stent. RESULTS A total of 145 patients were randomized; 13 were excluded. Sixty-four patients who received a Z-stent and 68 who had a Wallstent are included in the analysis. Tumors responsible for bile duct obstruction were pancreatic cancer (108), cholangiocarcinoma (15), metastatic cancer (6), and papillary cancer (3). Metallic stents were successfully placed in all patients. Seven technical problems were encountered during placement of the Z-stent and 5 with the Wallstent. There were 21 occlusions requiring reintervention (8 Z-stent, 13 Wallstent; p = 0.30). Median time to reintervention was the following: Z-stent, 162 days; Wallstent, 150 days (p = 0.22). A total of 104 patients died of progressive disease or other cause; 7 patients remain alive with patent stents. The overall calculated median patency rates were: Z-stent, 152 days; Wallstent, 154 days (p = 0.90). CONCLUSIONS The Spiral Z-stent is comparable with the Wallstent in terms of placement, occlusion rates, and overall patency. Occasional early occlusion of both stents suggests tumor characteristics instead of the size of the mesh openings in the stents as important factors.

Medical device evaluation by the Food and Drug Administration (FDA).

VOLUME 53, NO. 7, 200

Management of occluded biliary wallstents

BACKGROUND Wallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion. AIMS To evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion. METHODS A multicentre retrospective study of patients managed for a biliary Wallstent occlusion. RESULTS Data were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30-1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5-34.3) to 2.1 (0.2-27.7) mg/100 ml (p < 0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22-118), 98 days (54-142), and 34 days (30-380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option. CONCLUSION Although all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.

7256 Multicenter randomized comparative trial of the new gianturco spiral z-stent compared to wallstent: study design and preliminary report of the zoom study.

Introduction: Evaluation of long-term patency for devices introduced for the treatment of extrahepatic malignant biliary obstruction require comparative trials in view of the high degree of variability among patients. Reported stent patencies of newly introduced products are frequently not confirmed in clinical practice (Gastrointest Endosc 1999:49:700(A)). New products, particularly those involving high risk interventions and high cost, should be studied carefully in multicenter trials to gain consensus as to their clinical utility.We propose to study the new spiral stent for malignant obstruction compared to the other metal stent (ZOOM). Study Goal: All our participating centers have obtained IRB approval to offer appropriate patients a randomized option of a standard uncoated Wallstent (Microvasive,Watertown, MA) or a new stainless steel uncoated Gianturco spiral Z-stent (Wilson-Cook, Winston-Salem, NC) for palliative treatment of malignant extrahepatic biliary obstruction. All strictures must be 2 cm or more below the bifurcation and patients must be in good physical condition as measured by a Karnofsky score of 60 or higher (Requires occasional care for most needs). Patients with prior temporary plastic stents can be accepted providing they do not show evidence of occlusion or cholangitis and have appropriate Karnofskys scores. Patients will then have serum bilirubins measured at 1 month and clinical follow-up on a monthly basis. Every effort will be made to determine the cause of stent occlusion. A study of sufficient power to detect a 20% difference in results has been calculated to require 200 patients to be enrolled. Preliminary Results: 24 patients have been randomized after successful guidewire placement through their malignant obstructions. 12 patients have received Wallstents and 12 patients have received spiral Z-stents. There have been no initial failures of stent placement. All patients have achieved initial biliary drainage. More extensive data of initial stent placement and initial drainage will be forthcoming as patients are enrolled with long-term patency data anticipated in the next 1-2 years. Conclusion: A large randomized controlled study of the newly introduced uncoated Gianturco spiral Z-stent is underway to compare procedural success, initial drainage and, most importantly, long-term patency. Such trials are needed to permit the most appropriate employment of new devices.