Bret T. Petersen

Magnetic resonance cholangiography in patients with biliary disease: its role in primary sclerosing cholangitis

BACKGROUND/AIM Magnetic resonance cholangiography (MRC) is a non-invasive diagnostic procedure whose role in the management of patients with primary sclerosing cholangitis (PSC) is unclear. The aim of this study was to determine the usefulness of MRC in the evaluation of the biliary tree in patients with suspected biliary disease, and in particular, PSC. METHODS MRC and invasive cholangiography (ERCP or PTC) were both performed in 73 patients, (33 male, 40 female, mean age 56 years) with clinical and/or biochemical evidence of cholestasis. Images were interpreted by two radiologists unaware of the results of other studies. RESULTS Forty-two patients (58%) had benign biliary disease, including 23 patients (32%) with PSC; 9 patients (12%) had malignant biliary disease; and 22 patients (30%) had a normal biliary tree. Diagnostic quality images were obtained in 73/73 (100%) of MRC, and in 70/73 (96%) of invasive cholangiography (68 ERCPs, 2 PTCs) procedures. Using ERCP/PTC findings as the reference standard, MRC had an accuracy greater than 90% in the diagnosis of normal bile ducts, biliary dilatation, biliary obstruction, bile duct stones, and PSC. Using the final diagnosis, MRC had an overall diagnostic accuracy of 90% in the detection of biliary disease compared to 97% for invasive cholangiography. Additional diagnostic/therapeutic interventions were performed during ERCP in 73% of patients with PSC and in 43% of patients without PSC (p=0.02). CONCLUSIONS MRC has excellent diagnostic accuracy in the presence of biliary disease. Because of its noninvasive nature, MRC may have advantages over invasive cholangiography when diagnosis is the major goal of the procedure.

Endoscopic decompression for acute colonic pseudo-obstruction

BACKGROUND Acute colonic pseudo-obstruction is often treated by colonoscopic decompression. Efficacy, safety, and outcome of endoscopic decompression was assessed. METHODS Colonoscopic decompressions from 1988 to 1994 were reviewed. Resolution without further endoscopic intervention was defined as clinical success. RESULTS Acute colonic pseudo-obstruction was diagnosed in 50 patients. Thirty-three cases followed surgery or trauma and 17 developed during severe medical illness. Orthopedic joint surgery was most common. Nineteen of 50 patients (38%) had severe underlying medical disease. Forty-one patients (82%) had one colonoscopic decompression with clinical success in 39 (95%). Nine patients (18%) required multiple (2 to 4) colonoscopic decompressions with clinical success in 5 (56%). A decompression tube positioned in the right colon (57%) and in the transverse colon (33%) had similar clinical success. In 8 procedures a decompression tube was not placed, with poor clinical success (25%). The overall clinical success of colonoscopic decompression was 88% (44 of 50). An endoscopic perforation occurred in 1 patient (2%). Overall hospital mortality was 30%. CONCLUSIONS Colonoscopic decompression is effective and safe for acute colonic pseudo-obstruction that does not respond to conservative therapy. Most patients will respond to one colonoscopic decompression with decompression tube placement. Complete colonoscopy and cecal tube placement is unnecessary.

3637 Efficacy of submucosal saline injection in the limitation of colonic thermal injury by electrosurgical devices.

Many colonoscopic therapies involve cutting or coagulation effects via delivery of thermal injury. Complications of these techniques include symptomatic transmural burn (post-polypectomy syndrome) and perforation. Submucosal saline injection (SMSI) has been advocated as a means of limiting depth of injury. The saline cushion acts as a heat-sink and increases transmural distance from burn to serosa. However, data are lacking regarding the efficacy of SMSI in limiting depth of thermal injury. Aim: To determine, in a porcine model, the effect of SMSI on depth of thermal injury to the colon due to a various modalities. Methods: Laparotomy under general anesthetic was performed and a longitudinal colotomy incision made on the antimesenteric side. Burns were made using bipolar goldprobe (20W, 2sec), heater probe (HP; 30J); monopolar (MP) contact with biopsy forceps (20W, 2sec), and MP non-contact with argon plasma coagulation (APC; 45W, 3sec); n ≥11 for each lesion. Burns were with or without prior injection of 2mL saline. The incision was closed and animals killed at 24hrs. Lesions were excised for histologic analysis. Injury was assessed by severe damage to the deep (longitudinal) muscle layer. Results: Non-SMSI lesions resulted in deep muscle injury in 86%, 61%, 50% and 18% for APC, MP contact, HP & bipolar, respectively. SMSI reduced risk of deep injury for APC and HP, but not monopolar contact (86%→21%; 50%→0% & 61%→50%, respectively). Conclusions: At equivalent energy outputs, bipolar current results in less deep injury than MP current or HP. Prolonged coagulation with the APC (45W) results in deep colonic injury. At the settings used, saline injection limits depth of injury due to both heater probe and APC, but not monopolar contact cautery. In spite of SMSI, caution should be used with prolonged monopolar cautery.

7040 A developmental endoscopy unit: paving the way for the future of endoscopy.

Endoscopy volumes continue to grow despite steady cut-backs in reimbursement. Significant physician and paramedical personnel time is needed to meet this growth providing less time for endoscopic research and development. AIM: To create an environment that facilitates endoscopic research and development. METHODS: A physician and paramedical personnel core group was assembled to include a director, lead gastrointestinal assistant, study coordinator, and research fellow. Dedicated space and equipment were provided. Contacts were established with industry to seek mutual areas of equipment, accessories, and technique development with an emphasis on confidentiality. A system of record keeping using the latest information technologies was established with a monthly and yearly reporting schedule for all activities. The working unit created was entitled the Developmental Endoscopy Unit (DEU). RESULTS: The DEU began operation on 8/1/98. The activities which evolved include: clinical research, prototype endoscope and accessory testing, animal research of new endoscopic techniques, the performance of complex clinical cases using cutting edge technology, and the invention of new equipment. The DEU physician endoscopist staff has grown from one to six. Planned personnel growth includes the addition of a gastrointestinal assistant and research coordinator. A total of 14 new research protocols were initiated the first year by the original core group. Projects include the study of high resolution and high magnification endoscopy, endoscopic anti-reflux methods, and tissue resection techniques. CONCLUSIONS: 1. Given the demanding pace of clinical endoscopy, it is possible to successfully assemble a working unit dedicated to promote the advancement of endoscopic care. 2. The DEU core group was able to efficiently establish a large number of both clinical and animal research projects. 3. The DEU structure enhanced communication and a developmental liaison with industry.

4644 Immediate and medium-term outcome of snare excision of the ampulla of vater.

Adenomatous change of the Ampulla of Vater is common in FAP patients, and also occurs sporadically, resulting in biliary obstruction, pancreatitis and malignancy. Although duodenal surveillance in FAP is advocated, optimal management of ampullary adenomas is uncertain. Snare excision of the ampulla has been reported to be safe in small numbers. Large studies of the outcome of this technique are desired. Aim: To determine the outcome of snare ampullectomy of the Ampulla of Vater. Methods: Patients were identified from a comprehensive endoscopic database. Data were accrued from the endoscopic database and patient records. 22 procedures utilized a polypectomy mini-snare and 5 procedures utilized a specialized ampullectomy snare (Olympus America, Corp, NY). Monopolar blended currents were used. All except 1 included a completion biliary endoscopic sphincterotomy (ES). All procedures were performed as out-patients, but patients remained locally for 24hrs post-procedure. Results: 27 snare ampullectomies were performed on 26 patients (1 pt had major and minor ampullectomies) between Sept.1997 and Nov. 1999 (14 males and 12 females). Median age 42yrs (range:21-84). 16 patients had FAP syndrome, 10 had sporadic lesions. 14 patients were asymptomatic; 12 symptomatic: epigastric pain (7), biliary obstruction (4) & recurrent pancreatitis (1). 9 patients received prophylactic pancreatic stents. 2 patients had minor ES bleeding. Four patients (15%) developed post-procedure pancreatitis: 2/9 with prophylactic stent vs. 2/18 without stents: p=0.5. No pancreatitis required hospitalization >2 days. 1 patient had an ES perforation that was hemoclipped and hospitalized for 2 days. 25 lesions were adenomas, 1 inflammatory polyp and 1 with invasive cancer who underwent pancreaticoduodenectomy. Endoscopic & histological follow-up is available in 15 patients (median: 7 months; range: 1-24 months). Two delayed complications occurred: pancreatitis due to orifice stenosis at 4 months and 24 months, treated with pancreatic ES and dilatation. F/U biopsies in 13 patients demonstrated normal tissue in 11 (85%), and residual adenomatous tissue with low grade dysplasia in 2. Conclusions: Snare ampullectomy of the ampulla of Vater is well tolerated. All acute complications were mild. Medium term follow-up biopsies show complete resection of adenomatous tissue in >85% of cases. Stenosis with pancreatitis may be a delayed sequelae.