Willis G. Parsons

Endoscopic pancreatic sphincterotomy: indications, outcome, and a safe stentless technique

BACKGROUND Endoscopic pancreatic sphincterotomy is less widely practiced than biliary sphincterotomy, in part because of the lack of firm data regarding its indications and safety. In addition, recent reports of ductal and parenchymal changes occurring after pancreatic stenting raise concerns about the standard practice of stent placement at the time of pancreatic sphincterotomy. We report our experience with pancreatic sphincterotomy and describe the use of a technique involving overnight nasopancreatic drainage rather than stenting. METHODS We reviewed the records of the 164 pancreatic sphincterotomies performed on 160 patients at our institution between January 1, 1991, and October 1, 1996, comparing procedures done with overnight nasopancreatic catheter placement with those done with stenting or no drainage. We also examined the long-term clinical outcome of patients after pancreatic sphincterotomy. RESULTS Of the 164 sphincterotomies, 98 were done with overnight nasopancreatic drainage, 50 with stent placement, and 16 with no drainage. Complications (all pancreatitis) were significantly more frequent in the group with no drainage (12.5%) as compared with those with drainage (0.7%); p < 0.003. Nasopancreatic drainage was as safe as stent placement, with no complications after 98 procedures. Pancreatic sphincterotomy was effective when used as primary therapy, with 64% of patients so treated experiencing complete and long-lasting resolution of symptoms after the procedure. CONCLUSIONS Pancreatic sphincterotomy is safe and effective, although pancreatic drainage is required to reduce the incidence of pancreatitis. Overnight nasopancreatic drainage is the method of choice, as it carries as low a complication rate as stent placement, but without the need for a repeat procedure, and presumably without the risk of ductal and parenchymal damage.

Comparative performance of uncoated, self-expanding metal biliary stents of different designs in 2 diameters: final results of an international multicenter, randomized, controlled trial.

BACKGROUND The Wallstent has remained the industry standard for biliary self-expanding metal stents (SEMSs). Recently, stents of differing designs, compositions, and diameters have been developed. OBJECTIVE To compare the new nitinol 6-mm and 10-mm Zilver stents with the 10-mm stainless steel Wallstent and determine the mechanism of obstruction. DESIGN Randomized, prospective, controlled study. SETTING Nine centers experienced in SEMS placement during ERCP. PATIENTS A total of 241 patients presenting between September 2003 and December 2005 with unresectable malignant biliary strictures at least 2 cm distal to the bifurcation. MAIN OUTCOME MEASUREMENT Stent occlusions requiring reintervention and death. RESULTS At interim analysis, a significant increase in occlusions was noted in the 6-mm Zilver group at the P = .04 level, resulting in arm closure but continued follow-up. Final study arms were 64, 88, and 89 patients receiving a 6-mm Zilver, 10-mm Zilver, and 10-mm Wallstent, respectively. Stent occlusions occurred in 25 (39.1%) of the patients in the 6-mm Zilver arm, 21 (23.9%) of the patients in the 10-mm Zilver arm, and 19 (21.4%) of the patients in the 10-mm Wallstent arm (P = .02). The mean number of days of stent patency were 142.9, 185.8, and 186.7, respectively (P = .057). No differences were noted in secondary endpoints, and the study was ended at the 95% censored study endpoints. Biopsy specimens of ingrowth occlusive tissue revealed that 56% were caused by benign epithelial hyperplasia. CONCLUSIONS SEMS occlusions were much more frequent with a 6-mm diameter SEMS and equivalent in the two 10-mm arms despite major differences in stent design, material, and expansion, suggesting that diameter is the critical feature. Malignant tumor ingrowth produced only a minority of the documented occlusions.

Improved oral intake after palliative duodenal stenting for malignant obstruction: a prospective multicenter clinical trial.

OBJECTIVES:We sought to test the hypothesis that placement of a new nitinol duodenal self-expandable metallic stent (SEMS) for palliation of malignant gastroduodenal obstruction is effective and safe in allowing patients to tolerate an oral diet.METHODS:In a prospective multicenter study, SEMSs (Duodenal WallFlex, Boston Scientific) were placed to alleviate gastroduodenal obstruction in inoperable patients without the ability to tolerate solid food. The primary study end point was improvement in oral intake monitored according to the 4-point Gastric Outlet Obstruction Scoring System (GOOSS) up to 24 weeks after stent placement.RESULTS:Forty-three patients received SEMSs, which were successfully deployed on the first attempt in 41 cases (95%) and the second attempt in two (5%). Within 1 day and 7 days after SEMS placement, 52% and 75% of patients, respectively, benefited from a GOOSS increase ≥1. Resumption of solid food intake (GOOSS 2–3) was attained by 56% of patients within 7 days and 80% by 28 days. Of the patients attaining GOOSS 2–3, 48% remained on solid food until death or last follow-up. Device-related adverse events included stent occlusion/malfunction in 9% of patients and perforation in 5% of patients.CONCLUSIONS:Duodenal WallFlex stent placement promptly improves oral intake in a majority of inoperable patients with malignant gastroduodenal obstruction. In approximately half the patients achieving GOOSS 2–3, the capacity for solid food intake endures until death or last follow-up.

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.

EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY OF PANCREATIC DUCT STONES USING THE HEALTHTRONICS LITHOTRON LITHOTRIPTOR AND THE DORNIER HM3 LITHOTRIPSY MACHINE

PURPOSE Pancreatic duct stones, which are most often a result of alcohol induced chronic pancreatitis, can lead to chronic abdominal pain, pseudocysts, and exocrine and endocrine failure of the pancreas. Others have reported success using extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia) for pancreatic stones. We report our experience with pancreatic ESWL using the LithoTron (Healthtronics, Marietta, Georgia) and HM3 (Dornier) lithotripsy machines. MATERIALS AND METHODS We performed pancreatic ESWL in 23 patients in 4 years, including in 12 with the LithoTron and in 11 with the HM3. After ESWL endoscopic retrograde cholangio-pancreatography (ERCP) was performed in all cases. Stone-free status was defined as no stone fragments visualized or the elimination of all post-ESWL stones by ERCP. RESULTS Stone-free status was documented in 83% and 82% of patients treated with the LithoTron and HM3, respectively, and 2 per group later required open surgical intervention. There were no changes in pancreatic enzymes and no cases of sepsis or fever after ERCP. CONCLUSIONS In association with post-procedure ERCP pancreatic ESWL is an effective and safe procedure that enables patients with obstructing pancreatic duct stones recalcitrant to primary endoscopic extraction to avoid a potentially morbid open procedure. The HM3 and LithoTron have comparable efficacy and safety. This modality is particularly effective for a stone aggregate of less than 20 mm., while a larger stone burden of greater than 20 mm. in aggregate and multiple stones are clear risk factors for treatment failure.

Percutaneous Hepatolithotomy: The Northwestern University Experience

Obstruction of intrahepatic ducts by calculi can lead to abdominal pain, cholestasis, abscesses, and cholangitis. Patients with stones recalcitrant to extraction using endoscopic retrograde cholangiopancreatography (ERCP) have traditionally been referred to a general surgeon for open stone extraction or hepatic lobectomy despite its great potential morbidity. Borrowing techniques, instrumentation, and experience in performing percutaneous nephrolithotomy, we describe our experience with percutaneous hepatolithotomy (PHL), a minimally invasive, safe, and effective alternative to open surgery for recalcitrant biliary stones.

Malignant biliary obstruction: endoscopic approaches.

Malignant obstruction of the biliary tree can occur at different sites; intrahepatic, perihilar, and extrahepatic. Symptoms of biliary obstruction vary significantly from patient to patient but may include right upper quadrant abdominal pain, back or shoulder pain, pruritis, jaundice, acholic stool, dark urine, and fatigue. Less than ten percent of malignancies involving the biliary tree will present with evidence of cholangitis; typical symptoms of biliary obstruction along with fever, chills, or bacteremia. A multidisciplinary team approach involving gastroenterologists, surgeons, interventional radiologists, and oncologists is often required for managing patients with malignant biliary obstruction. This chapter will focus on endoscopic approaches for alleviating biliary obstruction, either as a palliative technique for unresectable tumors or as a bridge to surgery for potentially curable tumors.

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.

7255 Identification and validation of a predictive model to determine the likelihood of choledocholithiasis.

BACKGROUND & AIMS: A predictive model using biochemical and noninvasive imaging characteristics to determine the likelihood of choledocholithiasis (CDL) will enable improved decision making and resource allocation. We sought to develop and validate an accurate predictive model to predict the likelihood of retained stone in patients with suspected CDL. METHODS: The records of all patients undergoing ERCP for evaluation of suspected CDL were reviewed. Demographic, historical, biochemical and imaging data were collated. The data was randomly assigned to a developmental and a validation sample. Using forward stepwise multivariate logistic regression, a predictive model using univariate predictors of CDL was developed. The most parsimonius predictive model was chosen and validated using receiver-operator curves (ROC) in the development and validation data samples. RESULTS: Three hundred and forty eight patients (296 females and 52 males) were included in the total sample. The overall prevalence of CDL in our sample was 28.3%. Hyperbilirubinemia (>2.5mg/dl), alkaline phosphatase(>300mg/dl), common bile duct dilatation and ultrasound evidence of CDL were significant predictors of CDL. Other significant predictors were Hispanic origin and age >65 years. The final multivariate model had a sensitivity of 76%, specificity of 81%, positive predictive value of 81% and a negative predictive value of 75%. The probability of CBD stone was 94% in patients with all identified predictors and 5.92% in patients without any of the predictors CONCLUSION: A validated logistic model using a combination of biochemical and imaging predictors is useful in determining the likelihood of retained stone in patients with suspected CDL