Establishment of Standards for the Referral of Large Non-Pedunculated Colorectal Polyps: An International Expert Consensus Using a Modified Delphi Process

BACKGROUND AND AIMS

Resection of colorectal polyps has been shown to decrease the incidence and mortality of colorectal cancer. Large non-pedunculated colorectal polyps are often referred to expert centres for endoscopic resection, which requires relevant information to be conveyed to the therapeutic endoscopist to allow for triage and planning of resection technique. The primary objective of our study was to establish minimum expected standards for the referral of LNPCP for potential ER.

METHODS

A Delphi methodology was employed to establish consensus on minimum expected standards for the referral of large colorectal polyps among a panel of international endoscopy experts. The expert panel was recruited through purposive sampling, and three rounds of surveys were conducted to achieve consensus, with quantitative and qualitative data analysed for each round.

RESULTS

A total of 24 international experts from diverse continents participated in the Delphi study, resulting in consensus on 19 statements related to the referral of large colorectal polyps. The identified factors, including patient demographics, relevant medications, lesion factors, photodocumentation and the presence of a tattoo, were deemed important for conveying the necessary information to therapeutic endoscopists. The mean scores for the statements ranged from 7.04 to 9.29 out of 10, with high percentages of experts considering most statements as a very high priority. Subgroup analysis by continent revealed some variations in consensus rates among experts from different regions.

CONCLUSION

The identified consensus statements can aid in improving the triage and planning of resection techniques for large colorectal polyps, ultimately contributing to the reduction of colorectal cancer incidence and mortality.

A156 OUTCOMES FOLLOWING ENDOSCOPIC RESECTION OF GASTRIC NEUROENDOCRINE TUMOURS FROM A TERTIARY-CARE ACADEMIC CENTRE

Background

Gastric neuroendocrine tumours (G-NET) are rare cancers derived from neuroendocrine cells of the stomach. A steady increase in the incidence of these tumours has been observed. Current treatment and surveillance strategies are guided by various tumour characteristics including size, grade, and depth of invasion. There exists conflicting evidence, however, on the rates of recurrence from positive resection margins following primary endoscopic resection. Thus, it remains uncertain whether complete endoscopic resection (R0) of these indolent tumours is clinically significant and whether follow-up endoscopic or surgical intervention is justified.

Purpose

Our aim is to characterize current management patterns and clinical outcomes in patients undergoing endoscopic resection of G-NETs.

Method

We conducted a retrospective, single-centre cohort study at The Centre for Advanced Therapeutic Endoscopy and Endoscopic Oncology at St. Michael’s Hospital, Toronto, Ontario. Consecutive patients over the age of 18 who underwent endoscopic resection of histologically proven G-NETs between 2011 and 2020 were included. Data on patient, endoscopic, and tumour characteristics were collected through electronic chart review. Descriptive statistics were conducted for data analysis.

Result(s)

A total of 155 foregut neuroendocrine tumours were endoscopically resected during the study period, of which 108 were identified as G-NETs. 95.3% were classified as Type I. Mean tumour size was 8.93 ± 5.27 mm. Cap-assisted EMR was performed most frequently (n=51), followed by conventional EMR (n=35). ESD was performed in eight cases. Seven intra-procedural perforations occurred, of which all were closed endoscopically. One patient experienced post-procedural perforation requiring ICU and surgery. Positive resection margins (R1) were found in 25% of cases (n=27), of which 78% were assessed at surveillance endoscopy 1 (SE1). Six patients with R1 margins were referred for surgical evaluation and four were lost to follow-up. 78% of all resected G-NETs were followed at SE1 with a median interval of 196 days (range, 23 to 3373). SE1 recurrence rate at the primary resection site was 14% (n=12), of which two were from routine scar biopsies in the absence of endoscopically identifiable recurrence. All visible recurrences at these sites (n=10) were managed with repeat endoscopic resection. Patient and tumour characteristics in the evaluation of G-NET recurrence are presented in Table I.

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Conclusion(s)

G-NET recurrence occurs in less than 15% of patients at surveillance endoscopy following endoscopic resection in spite of a predictably higher R1 resection rate. Patient, endoscopic, and tumour factors including method of resection and margin status do not appear to impact the development of early recurrence. Given the indolent nature of these tumours, patients with positive resection margins can be followed conservatively. Further investigation is warranted to determine the optimal duration and surveillance strategy for these patients.

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Disclosure of Interest

None Declared

A155 OUTCOMES FOLLOWING ENDOSCOPIC RESECTION OF DUODENAL NEUROENDOCRINE TUMOURS FROM A TERTIARY-CARE ACADEMIC CENTRE

Background

Duodenal neuroendocrine tumours (D-NET) are rare cancers derived from neuroendocrine cells of the duodenum. A steady increase in the incidence of these tumours has been observed. Current treatment and surveillance strategies are guided by various tumour characteristics including size, grade, and depth of invasion. There exists conflicting evidence, however, on the rates of recurrence after positive resection margins following endoscopic resection. Thus, it remains uncertain whether complete endoscopic resection (R0) of these indolent tumours is clinically significant and whether follow-up endoscopic or surgical intervention is justified.

Purpose

Our aim is to characterize endoscopic management and clinical outcomes in patients undergoing endoscopic resection of D-NETs.

Method

We conducted a retrospective, single-centre cohort study at The Centre for Advanced Therapeutic Endoscopy and Endoscopic Oncology at St. Michael’s Hospital, Toronto, Ontario. Consecutive patients over the age of 18 who underwent endoscopic resection of histologically proven D-NETs between 2011 and 2020 were included. Data on patient, endoscopic, and tumour characteristics were collected through electronic chart review. Descriptive statistics were conducted for data analysis.

Result(s)

A total of 155 foregut neuroendocrine tumours (NET) were endoscopically resected amongst 96 patients during the study period. 47 of these were histologically identified as D-NETs. Mean tumour size was 9.88 ± 6.86 mm. Conventional endoscopic mucosal resection (EMR) was performed most frequently (55%, n=26/47), followed by cap-assisted EMR (30%, n=14/47). Hybrid endoscopic submucosal dissection (ESD)/EMR was performed in one case. A total of two intra-procedural perforations occurred, both of which were successfully closed endoscopically. One patient with a peri-ampullary D-NET experienced significant intra-procedural bleeding requiring Hemospray® and subsequent endotracheal intubation resulting in a brief hospitalization. 57% of all resected D-NETs were followed at surveillance endoscopy 1 (SE1) at a median interval of 199 days (range, 84 to 830). Positive resection margins (R1) were found in 26 cases (55%), of which 16 were assessed at SE1 while nine were lost to follow-up. One patient with R1 margins was electively treated with APC at SE1. Tumour recurrence at SE1 occurred in only two patients.

Image

Conclusion(s)

D-NET recurrence is found in less than 5% of patients at surveillance endoscopy following endoscopic resection in spite of a high R1 resection rate. Given this indolent nature of these tumours, our study suggests that patients with positive resection margins can be followed conservatively with surveillance endoscopy. Further investigation is warranted to determine the optimal duration and surveillance strategy for these patients.

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CAG

Disclosure of Interest

None Declared

Endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography for patients with Roux-en-Y gastric bypass anatomy: technical overview

Endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y gastric bypass anatomy is a well-documented challenge. Traditionally, this problem has been overcome with adjunctive techniques, such as device-assisted ERCP, including double-balloon or single-balloon enteroscopy and laparoscopy-assisted transgastric ERCP. Endoscopic ultrasound-directed transgastric ERCP (EDGE) is a novel technique that enables access to the ampulla using a duodenoscope without surgical intervention and has shown high clinical and technical success rates in recent studies. However, this approach is technically demanding, necessitating a thorough understanding of the gastrointestinal anatomy as well as high operator experience. In this review, we provide a technical overview of EDGE in parallel with our personal experience at our center and propose a simple algorithm to select patients for its appropriate application. In conjunction, the outcomes of EDGE compared with those of device-assisted and laparoscopy-assisted transgastric ERCP will be discussed.

Predictors of Malignancy in Patients With Indeterminate Biliary Strictures and Atypical Biliary Cytology: Results From Retrospective Cohort Study

Background

Atypical cellular features are commonly encountered in patients with indeterminate biliary strictures, which are nondiagnostic of malignancy yet cannot rule it out. This study aims to identify clinical features that could discriminate patients with indeterminate biliary strictures and atypical biliary cytology who may harbor underlying malignancy.

Methods

All patients with an indeterminate biliary stricture and an atypical brush cytology obtained during endoscopic brushings were identified in a large tertiary-care center. Demographical information, clinical data and the final pathological diagnosis were collected. The study cohort was divided based on the final diagnosis into benign and malignant groups. Descriptive and multivariable analyses were performed.

Results

A total of 151 patients were included in the analysis. Of these, 62.9% were males with mean age of 61.7 ± 16.4 years. Overall, there was an almost equal distribution of patients in the benign and malignant groups. Older age (≥65 years), jaundice, weight loss, intrahepatic biliary and pancreatic duct dilation, double-duct sign and presence of a mass were associated with malignancy in the univariate analysis. However, only older age (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.00 to 1.03), jaundice (OR 3.33, 95% CI 1.11 to 9.98) and presence of a mass (OR 12.10, 95% CI 4.94 to 29.67) were significantly associated with malignancy in the multivariate analysis. High CA19-9 was associated with malignancy only in patients with primary sclerosing cholangitis.

Conclusion

In patients with indeterminate biliary stricture and atypical brush cytology, older age, jaundice and presence of a mass are significant predictors of malignancy. Patients with such characteristics need prompt evaluation to rule out underlying malignancy.

Management of combined malignant biliary-duodenal obstruction in Roux-en-Y gastric bypass anatomy with EUS-guided gastrogastrostomy, EUS biliary drainage, and duodenal stent placement

Video 1Demonstration of deploying lumen-apposing metal stents for gastrogastrostomy and choledochoduodenostomy in a patient with Roux-en-Y gastric bypass anatomy, as well as EUS-guided fine needle biopsy for pancreatic mass.

Recovery of endoscopy services in the era of COVID-19: recommendations from an international Delphi consensus

The COVID-19 pandemic has had a profound impact on provision of endoscopy services globally as staff and real estate were repurposed. As we begin to recover from the pandemic, a cohesive international approach is needed, and guidance on how to resume endoscopy services safely to avoid unintended harm from diagnostic delays. The aim of these guidelines is to provide consensus recommendations that clinicians can use to facilitate the swift and safe resumption of endoscopy services. An evidence-based literature review was carried out on the various strategies used globally to manage endoscopy during the COVID-19 pandemic and control infection. A modified Delphi process involving international endoscopy experts was used to agree on the consensus statements. A threshold of 80% agreement was used to establish consensus for each statement. 27 of 30 statements achieved consensus after two rounds of voting by 34 experts. The statements were categorised as pre-endoscopy, during endoscopy and postendoscopy addressing relevant areas of practice, such as screening, personal protective equipment, appropriate environments for endoscopy and infection control precautions, particularly in areas of high disease prevalence. Recommendations for testing of patients and for healthcare workers, appropriate locations of donning and doffing areas and social distancing measures before endoscopy are unique and not dealt with by any other guidelines. This international consensus using a modified Delphi method to produce a series of best practice recommendations to aid the safe resumption of endoscopy services globally in the era of COVID-19.

Real-time transabdominal ultrasound-guided ERCP is feasible and effective in pregnancy: a case series

Background and study aims  Endoscopic retrograde cholangiopancreatography (ERCP) is commonly required in pregnancy for choledocholithiasis, however, radiation exposure is a major concern for patients. Real-time transabdominal (TA) ultrasound (US)-guided ERCP is a radiation-free technique that facilitates confirmation of biliary cannulation, equipment exchange and stone clearance. We present the largest Western case series of this modality in pregnancy and a review of the literature. Four pregnant adult patients were referred to our tertiary center with suspected or documented choledocholithiasis and underwent real-time TA US-guided ERCP. US was successfully used to confirm positioning of the guidewire and ductal clearance. Procedures were successful in all patients with resolution of clinical symptoms and no immediate procedural complications. Two patients suffered adverse events later in their pregnancy. Real-time TA US-guided ERCP is a technically feasible and effective modality that can be offered to obtain biliary access in a radiation-free fashion for specific subsets of pregnant patients with choledocholithiasis. Future studies are needed to confirm the safety of this technique.

Clinical and pathological predictors of failure of endoscopic therapy for Barrett's related high-grade dysplasia and early esophageal adenocarcinoma

BACKGROUND AND AIMS

Multimodal endoscopic treatment for Barrett's esophagus (BE) related high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) is safe and effective. However, there is a paucity of data to predict the response to endoscopic treatment. This study aimed to identify predictors of failure to achieve complete eradication of neoplasia (CE-N) and complete eradication of intestinal metaplasia (CE-IM).

METHODS

We performed a retrospective analysis of prospectively collected data of all HGD/EAC cases treated endoscopically at a tertiary referral center. Only patients with confirmed HGD/EAC from initial endoscopic mucosal resection (EMR) were included. Potential predictive variables including clinical characteristics, endoscopic features, and index histologic parameters of the EMR specimens were evaluated using multivariate Cox regression.

RESULTS

A total of 457 patients were diagnosed with HGD/EAC by initial EMR from January 2008 to January 2019. Of these, 366 patients who underwent subsequent endoscopic treatment with or without RFA were included. Cumulative incidence rates at 3 years for CE-N and CE-IM were 91.4% (95% CI 87.8-94.2%) and 66.8% (95% CI 61.2-72.3%), respectively during a median follow-up period of 35 months. BE segment of 3-10 cm (HR 0.45; 95% CI 0.36-0.57) and > 10 cm (HR 0.25; 95% CI 0.15-0.40) were independent clinical predictors associated with failure to achieve CE-N. With respect to CE-IM, increasing age (HR 0.88; 95% CI 0.78-1.00) was another predictor along with BE segment of 3-10 cm (HR 0.37; 95% CI 0.28-0.49) and > 10 cm (HR 0.15; 95% CI 0.07-0.30). Lymphovascular invasion increased the risk of CE-N and CE-IM failure in EAC cases.

CONCLUSION

Failure to achieve CE-N and CE-IM is associated with long-segment BE and other clinical variables. Patients with these predictors should be considered for a more intensive endoscopic treatment approach at expert centers.

Portopulmonary venous anastomosis as a rare cause of embolic stroke following endoscopic cyanoacrylate injection for gastric variceal hemorrhage: A case report and review of the literature

We report the case of a non‐cirrhotic 25‐year‐old female patient with cryptogenic portal hypertension who underwent cyanoacrylate injection for acute gastroesophageal variceal bleeding with a subsequent embolic stroke via a previously unrecognised portopulmonary venous anastomosis.

Clinical characteristics may distinguish patients with esophageal adenocarcinoma arising from long- versus short-segment Barrett's esophagus

BACKGROUND AND AIMS

Patients with long-segment Barrett's esophagus (LSBE; ≧3 cm) have higher risk of developing esophageal adenocarcinoma (EAC) than those with short-segment Barrett's esophagus (SSBE; <3 cm). However, it is unclear whether patients developing EAC from LSBE or SSBE differ significantly according to baseline clinical characteristics.

METHODS

We conducted a retrospective analysis of a prospectively maintained database comprising consecutive patients with early EAC treated by endoscopic mucosal resection at a single, tertiary-referral center. Information regarding baseline clinical characteristics were determined. Univariate and multivariate logistic regression were performed to identify factors that differed significantly between patients with EAC arising from SSBE and LSBE.

RESULTS

A total of 145 LSBE EAC and 179 SSBE EAC cases were identified. The LSBE EAC patients had a stronger association with having a hiatal hernia compared to the SSBE EAC patients. In contrast, inverse associations were observed in LSBE EAC patients with statin use and smoking pack-years relative to SSBE EAC patients.

CONCLUSIONS

Patients who developed EAC on a background of LSBE were more likely to have a hiatus hernia compared to patients with SSBE EAC, who were more likely to have higher smoking pack-years and higher rates of statin use.

Endoscopic Resection of Ampullary Tumours: Long-term Outcomes and Adverse Events

Background

The management of ampullary lesions has shifted from surgical approach to endoscopic resection. Previous reports were limited by small numbers of patients and short follow-up. The aim of this study is to describe short- and long-term outcomes in a large cohort of patients undergoing endoscopic ampullectomy.

Methods

Retrospective study of endoscopic ampullectomies performed at a tertiary center from January 1999 to October 2016. Information recorded includes patient demographics, clinical outcomes, lesion pathology, procedural events, adverse events and follow-up data.

Results

Overall, 103 patients underwent endoscopic resection of ampullary tumours (mean age 62.3 ± 14.3 years, 50.5% female, mean lesion size 20.9 mm; 94.9% adenomas, with a majority of lesions exhibiting low-grade dysplasia (72.7%). Complete endoscopic resection was achieved in 82.5% at initial procedure. Final complete endoscopic resection was achieved in all patients with benign pathology on follow-up procedures. Final pathology showed that 11% had previously undiagnosed invasive carcinoma. Delayed postprocedure bleeding occurred in 21.4%, all of which were managed successfully at endoscopy. Acute pancreatitis complicated 15.5% of procedures (mild in 93.8%). Perforation occurred in 5.8%, all treated conservatively except for one patient requiring surgery. Piecemeal resection was associated with significantly higher recurrence compared to en-bloc resection (54.3% versus 26.2%, respectively, P = 0.012). All recurrences were treated endoscopically.

Conclusion

Endoscopic ampullectomy appears both safe and effective in managing patients with ampullary tumours in experienced hands. Most adverse events can be managed conservatively. Many patients develop recurrence during long-term follow-up but can be managed endoscopically. Recurrence rates may be reduced by performing initial en-bloc resection.

Endoscopic Ultrasound-Guided Vascular Therapy: The Present and the Future

Endoscopic ultrasound (EUS) offers access to many intra-abdominal vessels that until now have only been accessible to the surgeon and interventional radiologist. In addition to assisting with diagnostics, this unique access offers the potential for therapeutic intervention for a host of indications. To date, this has had the most clinical impact in the treatment of gastroesophageal varices, with EUS-guided coil and glue application growing in use worldwide. Although randomised controlled trial data is lacking, we discuss the growing body of literature behind EUS-guided therapy in the management of varices. EUS has also been used in specialized centres to assist in non-variceal gastrointestinal bleeding. The treatment of bleeding from Dieulafoy lesions, tumours and pancreatic pseudoaneurysms has all been described. The potential applications of EUS have also extended to the placement of portal vein stents and porto-systemic shunts in animal models. As medicine continues to move to increasingly less invasive interventions, EUS-guided therapies offer substantial promise for the safe and effective delivery of targeted treatment for a widening array of vascular disorders.

Endoscopic Ultrasound-Guided Pancreatic Duct Intervention

Endoscopic ultrasound-guided pancreatic duct intervention (EUS-PDI) is an emerging endoscopic approach allowing access and intervention to the pancreatic duct (PD) for patients with failed endoscopic retrograde pancreatography (ERP) or patients with surgically altered anatomy. As opposed to biliary drainage for which percutaneous drainage is an alternative following failed endoscopic retrograde cholangiopancreatography (ERCP), the treatment options after failed ERP are very limited. Therefore, endoscopic ultrasound (EUS)-guided access to the PD and options for subsequent drainage may play an important role as an alternative to surgical intervention. However, this approach is technically demanding with a high risk of complications, and should only be performed by highly experienced endoscopists. In this review, we describe an overview of the current endoscopic approaches, basic technical tips, and outcomes using these procedures.

Non-operative Management of Necrotic Pancreatic Collection and Bleeding Pseudoaneurysm Communicating with Bowel Lumen at Multiple Sites: a Case Report and Review of the Literature

Pancreatic pseudocysts and foci of walled-off necrosis (WON) are well-known complications of acute pancreatitis. We present a case of severe gallstone pancreatitis complicated by WON, fistulization to the bowel and gastrointestinal bleeding. Bleeding was localized to a pseudoaneurysm of the gastroduodenal artery within the WON using imaging and endoscopy. Angiography and image-guided therapy were then used to control bleeding with coil-embolization. To our knowledge, this is the first report of non-operative management of a patient with severe pancreatitis complicated by WON and a bleeding pseudoaneurysm with multiple communications to the hollow viscera. Therapeutic options are discussed and a thorough literature review is included.

Efficacy of single-incision needle-knife biopsy for sampling subepithelial lesions

Background and study aims Single-incision needle-knife (SINK) biopsy is a diagnostic method for acquiring tissue samples for subepithelial lesions (SELs). A single linear incision is made in the overlying mucosa and tissue samples are obtained by passing conventional biopsy forceps through the opening and deep into the lesion. The aim of this study was to describe the efficacy and safety of this technique. Patients and methods Consecutive patients who underwent SINK biopsy for an upper gastrointestinal SEL between October 2013 and September 2015 were retrospectively reviewed. Results Forty-nine patients underwent 50 SINK biopsies. Sufficient sampling for a definite pathologic diagnosis was obtained in 42 (86 %) cases, with 91 % (40/44) having sufficient sample to perform immunohistochemistry when deemed clinically relevant. Of the 26 patients with prior non-diagnostic biopsies or FNA, a specific diagnosis was obtained in 85 % (22/26). There were no significant adverse events. Conclusions SINK biopsy is a safe and feasible strategy for obtaining a definitive tissue diagnosis with immunohistochemistry for SELs.

Clinical practice guideline: management of acute pancreatitis

ABSTRACT

There has been an increase in the incidence of acute pancreatitis reported worldwide. Despite improvements in access to care, imaging and interventional techniques, acute pancreatitis continues to be associated with significant morbidity and mortality. Despite the availability of clinical practice guidelines for the management of acute pancreatitis, recent studies auditing the clinical management of the condition have shown important areas of noncompliance with evidence-based recommendations. This underscores the importance of creating understandable and implementable recommendations for the diagnosis and management of acute pancreatitis. The purpose of the present guideline is to provide evidence-based recommendations for the management of both mild and severe acute pancreatitis as well as the management of complications of acute pancreatitis and of gall stone-induced pancreatitis.

Fluticasone propionate for treatment of esophageal lichen planus. A case series

Esophageal lichen planus is a rare condition, and although the majority of cases occur in conjunction with lichen planus at other sites, the endoscopic features are often misinterpreted resulting in a delay in diagnosis. We report a series of five patients presenting to our unit between 2005 and 2009. All five patients were female and presented with dysphagia. Endoscopy demonstrated proximal esophageal stricturing in four patients. Characteristic histological findings were found in four patients. Lichen planus was diagnosed at other sites, and preceded gastrointestinal symptoms, in all patients; five had oral involvement, two had genital involvement, and one had dermal involvement. All patients received proton pump inhibitor therapy without demonstrable benefit. Administration of oral fluticasone proprionate resulted in symptomatic improvement in three patients.

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.

Preoperative Chemoembolization in Patients with Hepatocellular Carcinoma Undergoing Liver Transplantation: Influence of Emergent Versus Elective Procedures on Patient Survival and Tumor Recurrence Rate

Our purpose was to compare the recurrence rate and survival in patients with hepatocellular carcinoma (HCC) who had elective transarterial chemoembolization (TACE), immediate preoperative TACE, or no treatment prior to orthotopic liver transplantation (OLT). A total of 132 patients with HCC had TACE prior to OLT. Eighteen patients had no TACE before OLT and functioned as a control group. The urgent group included 35 patients embolized less than 24 h before OLT and the elective group included 97 patients embolized greater than 1 day before transplantation. These groups were compared with regard to tumor staging, hepatic synthetic function, and post-TACE tumor necrosis and survival and recurrence rates. Patients were followed for a mean of 780 days post OLT (1-2912 days). The tumor staging was similar between groups but the Childs-Pugh score in the urgent and untreated group was significantly higher than that of the other groups. The degree of necrosis at explant was also significantly different between the two treated groups, with an average 35% necrosis in the patients embolized less than 24 h before OLT vs 77% in the elective group (p < 0.002). Recurrence rate in the urgent group was 8 of 35 (23%) in a median of 580 days, 20 of 97 (21%) in a median of 539 days in the elective group, and 2 of 18 (11%) in a median of 331 days in the no-TACE group. Survival at 1, 3, and 5 years was 91%, 80%, and 72% in the elective group, 79%, 58%, and 39% in the urgent group, and 69%, 61%, and 41% in the no-TACE group, respectively. The urgent and no-TACE groups had significantly worse survival compared with the other groups; however, the tumor recurrence rates were statistically the same among all three groups. TACE within 24 h of OLT causes an average of 35% necrosis and elective TACE increases necrosis further to 77%. Despite this difference, the tumor recurrence rate in the three groups is equivalent and no different from that in the group that received no treatment before OLT. The decreased survival in the immediate and no-TACE groups was due to non-cancer-related deaths.

Management of perforation after endoscopic retrograde cholangiopancreatography (ERCP): a population-based review

BACKGROUND

Perforation related to endoscopic retrograde cholangiopancreatography (ERCP) is a rare complication associated with significant morbidity and mortality. This study evaluated the management and outcomes of these perforations.

PATIENTS AND METHODS

Between July 1996 and December 2002, a total of 6620 ERCPs were performed at our regional endoscopy unit serving the 1.5 million population of Southern Alberta. Thirty perforations (0.45%) were identified and retrospectively reviewed. Results. Seven of these 30 patients were found to have guidewire perforations of the bile duct, 11 perforations were peri-ampullary, 3 duodenal, 1 esophageal, and 1 patient had a perforation of an afferent limb of a Billroth II anastomosis. In seven patients the location of the perforation could not be determined (unknown). All patients with guidewire perforations were recognized during ERCP, and all were managed medically. Of the 11 peri-ampullary perforations, 7 of these patients had a pre-cut sphincterotomy, 5 underwent surgery and 4 patients died. Delay in diagnosis occurred in all patients that died. Of the three duodenal perforations, all required operation and one patient died. Of the seven 'unknown' retroperitoneal perforations, two patients required surgery and there was no mortality. The patients with esophageal and afferent limb perforations both recovered uneventfully after surgery. Most patients who required surgery had retroperitoneal fluid seen on CT scanning.

CONCLUSIONS

We found that most guidewire perforations can be managed medically with little morbidity. Pre-cut sphincterotomy is a risk factor for perforation. Peri-ampullary and duodenal perforations have a high morbidity and mortality rate. In particular, retroperitoneal fluid collections on CT scans, delay in diagnosis and failure of medical therapy requiring salvage surgery are associated with poor outcomes. Early aggressive surgery may improve patient care.

Patterns of Use of Endoscopic Retrograde Cholangiopancreatography in a Canadian Province

BACKGROUND:Data on current endoscopic retrograde cholangiopancreatography (ERCP) practice patterns drawn from large population-based samples are limited.

METHODS:Patterns of ERCP use were determined using billing records for ERCP, sphincterotomy, stone extraction or stent placement performed between April 1, 1994 and March 31, 2002 in Alberta from a population-based administrative database. Age-sex adjusted rates (per 1000 population) were calculated using the 1991 Canadian population as the standard.

RESULTS:The eight-year average ERCP rate was 0.98 without evidence of an increasing or decreasing trend over time. The ERCP rate was 0.85 in men and 1.12 in women. Significant regional variation in ERCP rates was seen, ranging from a low of 0.64 to a high of 1.27. The proportion of procedures that were therapeutic increased from 33% in 1994 to 70% in 2001. The likelihood of a procedure being considered therapeutic varied with the age and sex of the patient as well as the health region in which the procedure was performed.

CONCLUSIONS:The ERCP rate remained relatively stable over an eight-year time period, but the proportion of procedures that were therapeutic increased dramatically. Important regional variation in ERCP rates and therapeutic procedures exists.

Gastrointestinal complications in bone marrow transplant patients

Complications of bone marrow transplantation are numerous, multifactorial and may affect any organ in the body. The involvement of the gastrointestinal system represents one of dominant sites of complications. Clinical management of gastrointestinal complications can be challenging in these patients. This overview summarizes common bone marrow transplantation related conditions affecting esophagus, stomach, small and large intestine as well as liver. These are discussed primarily from the clinical point of view with emphasis on the differential diagnosis. The histomorphologic features of these conditions are discussed as well.

C1 inhibitor deficiency and angioedema of the small intestine masquerading as Crohn's disease

A case of C1 inhibitor deficiency presenting as localized edema of the small intestine is described. A 16-year-old, previously healthy woman presented with recurrent attacks of abdominal pain and vomiting following minor abdominal trauma. Investigations including computed tomography scan and barium studies confirmed localized edema of the jejunum. At laparoscopy, Crohn's disease was suspected; however, a subsequent enteroscopy was normal. Complement levels revealed a low C4 level, and C1 inhibitor deficiency was later confirmed. Attacks of abdominal pain began after starting oral contraceptives and have not returned since stopping the birth control pill. This rare cause of abdominal pain is examined, and C1 inhibitor deficiency and angioedema are reviewed.

Azathioprine for maintaining remission of Crohn's disease

OBJECTIVES

To assess the effectiveness of azathioprine in maintaining remission of quiescent Crohn's disease.

SEARCH STRATEGY

Pertinent studies were selected using the MEDLINE data base (1966 - May 1998), the Cochrane Controlled Trials Register, the Inflammatory Bowel Disease Trials Register, as well as abstracts from major gastrointestinal research meetings and references from published articles and reviews.

SELECTION CRITERIA

Five randomized, double-blind, placebo-controlled trials of azathioprine therapy were identified. Two of these trials consisted solely of patients with quiescent Crohn's disease. Three trials had multiple therapeutic arms for both induction of remission and maintenance of remission.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers (GRM, GF, LRS) based on the intention to treat principle. Peto odds ratios for the overall maintenance of remission, steroid sparing, and withdrawals due to adverse effects were calculated, and from these, 95% confidence intervals were derived. Numbers needed to treat or harm (NNT, NNH respectively) for the maintenance of remission, steroid sparing, and withdrawals due to adverse effects were also determined.

MAIN RESULTS

Azathioprine had a positive effect on maintaining remission. The Peto odds ratio for maintenance of remission was 2.16 (CI 1.35 - 3.47) with an NNT of 7. A higher dose improved response. A steroid sparing effect was noted, with a Peto odds ratio of 5.22 (CI 1.06 - 25.68) and NNT of 3 for quiescent disease. The Peto odds ratio for withdrawals due to adverse events was 4.36 (CI 1.63 - 11.67), the NNH (Number Needed to Harm) was 19.

REVIEWER'S CONCLUSIONS

Azathioprine is effective in maintaining remission. There is evidence for a steroid sparing effect.

Inhibition by lifarizine of intracellular Ca2+ rises and glutamate exocytosis in depolarized rat cerebrocortical synaptosomes and cultured neurones

1. The effects of lifarizine (RS-87476) on intracellular Ca2+ rises and the release of glutamate from rat cerebrocortical synaptosomes depolarized with 30 mM KCl were investigated by use of entrapped fura 2 and exogenous glutamate dehydrogenase. 2. Prior (1 min) addition of lifarizine decreased 30 mM KCl-induced total glutamate release, with 3 microM and 10 microM causing 39% and 72% averaged decreases from controls. The calcium-dependent component of glutamate release (approx. 40% of total) was similarly decreased by 47% and 74%, whereas the calcium-independent component was decreased by only 32% and 43% respectively. 3. In parallel experiments with fura-2-loaded synaptosomes, lifarizine reduced the depolarization-induced increases in intracellular [Ca2+], suggesting that this is the means by which the decreases in glutamate release are brought about. Lifarizine inhibited both the plateau and the spike phases of the Ca2+ increases suggesting that, in addition to its known sodium channel blocking properties, it may also inhibit more than one class of calcium channel in the synaptosomes. 4. Lifarizine at 1 microM and 3 microM also inhibited the rises in intracellular [Ca2+] in rat cultured cortical neurons depolarized with 60 mM KCl. 5. These effects of lifarizine on intracellular Ca2+ and glutamate exocytosis may contribute to its neuroprotective action.

On the roles of long-chain acyl carnitine accumulation and impaired glucose utilization in ischaemic contracture development and tissue damage in the guinea-pig heart

It has been proposed that the presence of increasing concentrations of fatty acids may accelerate the development of ischaemic contracture and cardiac damage, and that this may be due to long-chain acyl carnitine accumulation and/or impairment of glucose utilization. In isolated guinea-pig papillary muscles, palmitoyl (DL) carnitine was found to have a positive inotropic effect, with a slow onset of action suggestive of an intracellular site of action, and with a maximal effect of about two-fold at a concentration of 5-10 microM; higher concentrations led to decreased contraction, probably due to increasing detergent-like effects. In isolated fura-2-loaded chick cardiomyocytes, palmitoyl carnitine increased intracellular [Ca2+]; it is proposed that this is the means by which it increases contraction. The main hypothesis above was studied using isolated guinea-pig hearts perfused with either 11.7 mM or 5 mM glucose, and either albumin alone (3%) or albumin bound palmitate (1.5 mM) during low-flow ischaemia (92% reduction in flow) for up to 60 min. With 11.7 mM glucose, the presence of palmitate caused contracture development and increased enzyme release during ischaemia. Contracture also developed when the glucose concentration was reduced to 5 mM in the absence of fatty acid, however, in its presence contracture developed to a greater extent and with increased enzyme release. Long-chain acyl carnitine accumulation was similar in both groups. These studies show that long-chain acyl carnitine accumulation has the potential to induce contracture during ischaemia, although a reduction in glucose availability may also contribute.

Meta-analysis of the role of oral contraceptive agents in inflammatory bowel disease

Numerous epidemiological studies have been performed to determine factors that might contribute to the development of inflammatory bowel disease. Although the role of oral contraceptive agents in Crohn's disease (CD) and ulcerative colitis (UC) have been assessed, most studies were of small sample size and characterised by low statistical precision. A meta-analysis was performed to increase the statistical power and to investigate the association between the use of oral contraceptives and the development of CD and UC. The study was based on a search of a Medline database from 1975 to October 1993 and a review of reference lists from published articles, reviews, symposia proceedings, and abstracts from major gastrointestinal meetings. All studies specifically designed to evaluate this association were selected. The combined results of nine studies--two cohort studies (30,379 unexposed and 30,673 exposed patients) and seven case-control studies (482 CD, 237 UC, and 3198 controls)--which satisfied our selection criteria were evaluated. The pooled relative risk (adjusted for smoking) associated with oral contraceptive use was 1.44 (1.12, 1.86) for CD and 1.29 (0.94, 1.77) for UC. These results suggest modest associations between the use of oral contraceptives and the development of CD and UC. As these associations are weak, non-causal explanations for the findings cannot be eliminated.

Azathioprine and 6-mercaptopurine in Crohn disease. A meta-analysis

PURPOSE

To assess the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn disease and the effectiveness of azathioprine in maintaining remission of quiescent disease.

DATA SOURCES

Pertinent studies were selected from the MEDLINE database (1966 to May 1994), abstracts from major gastrointestinal meetings, and references from published articles and reviews.

STUDY SELECTION

Nine randomized, placebo-controlled trials of azathioprine or 6-mercaptopurine therapy were identified: Four addressed active disease, two addressed quiescent disease, and three had multiple therapeutic arms.

DATA EXTRACTION

Data were extracted by three independent observers on the basis of the intention-to-treat principle and were analyzed with logistic regression. Each study was given a quality score on the basis of predetermined criteria.

DATA SYNTHESIS

Compared with placebo, azathioprine or 6-mercaptopurine therapy had an odds ratio of response of 3.09 (95% CI, 2.45 to 3.91) in patients with active Crohn disease. When the single trial that used 6-mercaptopurine in active disease was excluded from the analysis, the odds ratio of response was 1.45 (CI, 1.12 to 1.87). No trials of quiescent disease used 6-mercaptopurine; the odds ratio of response in these trials of quiescent disease was 2.27 (CI, 1.76 to 2.93). For active disease, continuation of therapy for at least 17 weeks improved response (P = 0.03). For quiescent disease, a higher dose improved response (P = 0.008). Increased cumulative dose improved response in both groups (P < 0.001 for active disease and P = 0.01 for quiescent disease). A steroid-sparing effect was seen in active disease (odds ratio, 3.69 (CI, 2.12 to 6.42) and in quiescent disease (odds ratio, 4.64 [CI, 1.00 to 21.54]). Fistulae improved with therapy (odds ratio, 4.44 [CI, 1.50 to 13.20]). Adverse events requiring withdrawal from a trial, primarily allergy, leukopenia, pancreatitis, and nausea, were increased with therapy (odds ratio, 5.26 [CI, 2.20 to 12.60]).

CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective in treating active Crohn disease and in maintaining remission. Cumulative dose was an important factor in predicting response. Adverse effects were more common among patients receiving therapy.

Neuroprotective profile of lifarizine (RS-87476) in rat cerebrocortical neurones in culture

1. The ability of the neuroprotective agent, lifarizine (RS-87476), to mitigate veratridine-, cyanide- and glutamate-induced toxicity in rat embryonic cerebrocortical neurones in primary culture has been compared with that of tetrodotoxin (TTX), nitrendipine, (+)-MK-801 and (-)-MK-801. Lactate dehydrogenase (LDH) released into the culture medium was used as the indicator of cell viability. 2. Incubation of cultures for 16 h in a medium containing veratridine (10(-4) M), sodium glutamate (10(-3) M) or sodium cyanide (10(-3) M) resulted in consistent elevations of LDH activity in the culture medium. The ability of compounds to attenuate these elevations was expressed as the concentration required to inhibit the increases in LDH release by 50% (IC50). 3. Neurotoxicity induced by veratridine was inhibited by lifarizine (IC50 = 4 x 10(-7) M), TTX (IC50 = 3 x 10(-8) M) and nitrendipine (IC50 = 3 x 10(-5) M). In contrast, (+)-MK-801 (up to 3 x 10(-5) M) was ineffective against this insult. 4. Glutamate-induced neurotoxicity was inhibited by (+)-MK-801 (IC50 = 1.4 x 10(-8) M) and to a lesser extent by (-)-MK-801 (IC50 = 1 x 10(-7) M), but was unaffected by lifarizine, TTX or nitrendipine (up to 10(-6) M). 5. (+)-MK-801 was effective against sodium cyanide-induced neurotoxicity (IC50 = 1.9 x 10(-8) M), whereas lifarizine and TTX (up to 10(-6) M) and nitrendipine (up to 3 x 10(-6) M) were without protective activity against this insult. 6. The results demonstrate that lifarizine potently protects rat cortical neurones in vitro against a neurotoxic insult that requires activation of sodium channels for its expression, and that the compound is ineffective against insults mediated by N-methyl-D-aspartate receptor activation. The weak efficacy of nitrendipine against veratridine-induced cell death argues against the involvement of L-type calcium channels in this insult. These data are consistent with the notion that the neuroprotective activity oflifarizine observed in vivo may be mediated by inhibition of neuronal sodium currents.

The role of nitric oxide as an endogenous regulator of platelet and neutrophil activation within the pulmonary circulation of the rabbit

1. Intravenous (i.v.) administration of adenosine diphosphate (ADP), platelet activating factor (PAF) and thrombin induced a dose-related accumulation of 111indium-labelled platelets within the thoracic region of anaesthetized rabbits. 2. I.v. administration of the inhibitor of NO biosynthesis, L-NG-nitro arginine methyl ester (L-NAME; 10 mg kg-1) significantly potentiated the peak platelet accumulation induced by ADP, PAF and thrombin. Additionally L-NAME prolonged the disaggregation of platelets in comparison to D-NAME (10 mg kg-1). Such changes were reversible by the administration of L-arginine (900 mg kg-1). 3. I.v. administration of PAF induced a small accumulation of 111indium-labelled neutrophils within the pulmonary circulation which could be greatly potentiated by pretreatment of the animals with L-NAME. In contrast, thrombin administration did not cause significant accumulation of 11indium-labelled erythrocytes in the pulmonary circulation of anaesthetized rabbits. 4. Intracarotid (i.c.) administration of thrombin induced a marked accumulation of radiolabelled platelets within the cranial vasculature which was not potentiated by the prior administration of L-NAME (at either 10 mg kg-1 or 100 mg kg-1). 5. These results suggest that endogenous NO may regulate platelet and polymorphonuclear leukocyte activation within the pulmonary but not the cerebral circulation of rabbits.

The effect of propofol on the canine sphincter of Oddi

To assess the effect of propofol on the canine sphincter of Oddi(SO), sphincter of Oddi manometry (SOM) was performed in fasting dogs which had undergone cholecystectomy and placement of modified Thomas duodenal cannulae. Using two water-perfused, single-lumen manometric catheters, SO and duodenal pressures were measured simultaneously. Baseline SO activity was recorded for at least one complete interdigestive cycle followed by bolus injections of propofol (Diprivan) (N = 31) from 0.1 to 4.0 mg/kg during Phase I of the Migrating Motor Complex (MMC). When propofol was administered in bolus doses < or = 0.4 mg/kg, no change in SO or duodenal motor function was seen. In doses > or = 0.5 mg/kg, SO basal pressure, amplitude, and frequency of contractions increased significantly. Increases in duodenal activity paralleled SO activity. Our results suggest that propofol in low doses may be useful for sedation during Sphincter of Oddi manometry in humans. Further studies of the effect of propofol on the human sphincter of Oddi are warranted.

Removal of stones from the bile duct at ERCP without sphincterotomy

The main risks associated with endoscopic stone removal arise from the sphincterotomy that is performed to facilitate stone extraction. The complication rate may be higher when the bile duct is not dilated. Between January 30, 1990, and March 30, 1993, we attempted to remove stones up to 8 mm in diameter through the intact papilla, without performing sphincterotomy, in 24 patients. Nine patients underwent balloon dilation of the sphincter or of a low duct stricture to facilitate stone removal. All patients were treated successfully and are well at follow-up. Two patients (one having had balloon dilation of the sphincter) had mild pancreatitis that required 2 days in the hospital. During the same period, 215 patients were treated for duct stones 8 mm or less through a standard sphincterotomy. Complications occurred in 11 of these patients: five episodes of pancreatitis, three infections, one perforation, and two other complications. Although these two groups of patients are not directly comparable, it appears that selected stones can be extracted from the bile duct without sphincterotomy with relative safety. This technique should be studied further, especially in younger persons where sphincter preservation may be desirable.

Gastrointestinal symptoms in ambulatory HIV-infected patients

Gastrointestinal symptoms are commonly seen in patients with established AIDS. We examined the charts of 258 HIV-infected patients attending our HIV outpatient clinic to determine: (1) the frequency of gastrointestinal symptoms in unselected HIV-infected patients and (2) if there are any predictors of the development of symptoms in initially asymptomatic patients. We found the overall frequency of gastrointestinal symptoms at initial presentation in our ambulatory, predominantly homosexual population of HIV-infected patients was 35% (95% CI 30-40%) with 19% having anorexia, 15% weight loss, 14% diarrhea, and 5% dysphagia. There was no association between the presence of symptoms and stool parasites, which were found in 51% of patients. In 165 patients who were initially asymptomatic, 72% subsequently developed symptoms over 36 months of actuarial follow-up. Patients with initial T4 counts < 500 were more likely to develop symptoms. Patients with a greater degree of immunosuppression as indicated by a lower T4 count, are more likely to develop gastrointestinal symptoms.

Is small intestinal permeability really increased in relatives of patients with Crohn's disease?

BACKGROUND

Patients with Crohn's disease have increased intestinal permeability, which may precede the development of clinical disease and be involved in disease pathogenesis. Subsequent studies have suggested that, as a group, first-degree relatives of patients with Crohn's disease do not have significantly increased small intestinal permeability rates. The present study proposes that conventional data analysis, used in these studies, may be inappropriate and has overlooked an important observation.

METHODS

Lactulose and mannitol permeabilities were defined in healthy controls and in patients with Crohn's disease and their first-degree relatives.

RESULTS

Intestinal permeability in relatives was similar to that in the control group, but a subpopulation had abnormally high permeability rates in the absence of clinical evidence for disease. Raw data from another investigator confirmed this finding in an additional study; consequently, it is concluded that the original hypothesis is still viable. A small proportion of individuals, at high risk of developing Crohn's disease, have increased intestinal permeability.

CONCLUSIONS

Increased intestinal permeability may precede clinical manifestations of Crohn's disease.

Efficacy of bile acid therapy for gallstone dissolution: a meta-analysis of randomized trials

To define better the efficacy of bile acid therapy for dissolution of radiolucent gallstones, we performed a meta-analysis of published trials from January 1966 to September 1992. Studies were identified using a MEDLINE computer search followed by an extensive manual search. The inclusion criteria used were: randomized trial, radiolucent gallstones in a visualizing gallbladder on oral cholecystography, and complete stone dissolution confirmed by oral cholecystography or ultrasound. Study results were pooled into 6 groups: placebo: high- and low-dose chenodeoxycholic acid (CDCA) (> or = 10 mg.kg/day and < 10 mg.kg/day); high- and low-dose ursodeoxycholic acid (UDCA) (> or = 7 mg.kg/day and < 7 mg.kg/day) and combined CDCA plus UDCA. Homogeneity calculations were performed and the percentage of complete stone dissolution calculated for each group with 95% confidence intervals. Of 66 trials identified, 23 comprising 1949 patients met the inclusion criteria. A total of 1062 patients were treated with CDCA, 819 with UDCA and 78 combination therapy. In studies > 6 months' duration, high-dose UDCA completely dissolved stones in 37.3% of patients (95% C.I. 33-42%), low-dose UDCA in 20.6%) and high-dose CDCA 18.2% (95% C.I. 15-21%). Based on only two studies, combination therapy achieved dissolution in 62.8% (95% C.I. 51-74%) of patients. Stones less than 10 mm dissolved significantly more frequently than stones larger than 10 mm. This analysis shows that UDCA in doses greater than 7 mg.kg/day taken for greater than 6 months will dissolve radiolucent gallstones in 38% of patients. The combination of UDCA and CDCA may be more efficacious but this observation is based upon only 78 patients and requires confirmation in further randomized trials.

Sulfasalazine revisited: a meta-analysis of 5-aminosalicylic acid in the treatment of ulcerative colitis

PURPOSE

To assess the effectiveness of the newer 5-aminosalicylic acid (5-ASA) delivery systems compared with placebo or sulfasalazine for the treatment of active ulcerative colitis and for the maintenance of remission.

DATA SOURCES

Pertinent studies were selected using the MEDLINE and BIOS (1981 to 1992) data bases, reference lists from published articles, reviews, symposia proceedings, and abstracts from major gastrointestinal meetings.

STUDY SELECTION

Randomized controlled trials of 5-ASA compared with placebo or sulfasalazine of a minimum of 4 weeks duration for active disease and a minimum of 6 months for maintenance of disease remission. Sixteen trials of 5-ASA for active disease, published either in abstract or full manuscript, were available. Eleven trials of 5-ASA for maintenance of remission were also reviewed.

DATA EXTRACTION

Crude rates for either induction of remission (active disease studies) or maintenance of remission (relapse-prevention trials) based on the intention-to-treat principle were extracted from the studies by two independent observers. Each study was given a quality score, based on predetermined criteria.

RESULTS

Studies were placed in three groups: 5-ASA compared with placebo, 5-ASA compared with sulfasalazine for active disease, and 5-ASA compared with sulfasalazine for maintenance of remission. 5-Aminosalicylic acid was superior to placebo in the treatment of active ulcerative colitis (pooled odds ratio, 2.02; 95% CI, 1.50 to 2.72). A dose-response effect for 5-ASA existed (P < 0.001). For active disease, the pooled odds ratio for 5-ASA compared with sulfasalazine was 1.15 (CI, 0.83 to 1.61). When 5-ASA was compared with sulfasalazine for maintenance of disease remission, the pooled odds ratio was 0.85 (CI, 0.64 to 1.15). Withdrawal rates and reported side effects were similar for 5-ASA compared with placebo- or sulfasalazine-treated patients.

CONCLUSIONS

Although the newer 5-ASA preparations in a dose of at least 2 g/d are more effective than placebo in the treatment of ulcerative colitis, insufficient evidence exists to suggest that they are superior to sulfasalazine. Although they offer a benefit to the sulfasalazine-sensitive patient, use of 5-ASA preparations instead of sulfasalazine in the treatment of ulcerative colitis cannot yet be substantiated.

The pharmacological modulation of thrombin-induced cerebral thromboembolism in the rabbit

1. Intracarotid (i.c.) administration of thrombin induced a marked accumulation of 111indium-labelled platelets and 125I-labelled fibrinogen within the cranial vasculature of anaesthetized rabbits. 2. Thrombin (100 iu kg-1, i.c.) - induced platelet accumulation was completely abolished by pretreatment with desulphatohirudin (CGP 39393; 1 mg kg-1 i.c., 1 min prior to thrombin). Administration of CGP 39393 1 or 20 min after thrombin produced a significant reduction in platelet accumulation. 3. Intravenous (i.v.) administration of the platelet activating factor (PAF) receptor antagonist BN 52021 (10 mg kg-1) 5 min prior to thrombin (100 iu kg-1, i.c.) had no effect on platelet accumulation. 4. An inhibitor of NO biosynthesis, L-NG-nitro arginine methyl ester (L-NAME; 100 mg kg-1, i.c.), had no significant effect on the cranial platelet accumulation response to thrombin (10 iu kg-1, i.c.) when administered 5 min prior to thrombin. 5. Defibrotide (32 or 64 mg kg-1 bolus i.c. followed by 32 or 64 mg kg-1 h-1, i.c., infusion for 45 min) treatment begun 20 min after thrombin (100 iu kg-1, i.c.) did not significantly modify the cranial platelet accumulation response. 6. Cranial platelet accumulation induced by thrombin (100 iu kg-1, i.c.) was significantly reversed by the fibrinolytic drugs urokinase (20 iu kg-1, i.c., infusion for 45 min), anisoylated plasminogen streptokinase activator complex (APSAC) (200 micrograms kg-1, i.v. bolus) or recombinant tissue plasminogen activator (rt-PA; 100 micrograms kg-1, i.c. bolus followed by 20 micrograms kg-1 min-1, i.c., infusion for 45 min) administered 20 min after thrombin.8. These results suggest that neither endogenous PAF nor NO modulate thrombin-induced intracranial platelet accumulation in the rabbit. However, fibrin deposition appears to play an important role as shown by the ability of fibrinolytic agents to reverse platelet and fibrinogen accumulation induced by i.c. thrombin.

Should elective endoscopic sphincterotomy replace cholecystectomy for the treatment of high-risk patients with gallstone pancreatitis?

Since the introduction of endoscopic sphincterotomy approximately 15 years ago, the indications for this procedure have expanded. Currently endoscopic sphincterotomy is the procedure of choice for management of retained common bile duct stones following cholecystectomy. It is also being used more frequently for choledocholithiasis with an intact gallbladder in high-risk patients and in some patients with acute gallstone pancreatitis. In patients recovering from an episode of gallstone pancreatitis, standard practice has been subsequent cholecystectomy with possible exploration of the common bile duct. To avoid surgery in high-risk patients, we propose that an elective endoscopic sphincterotomy may be a reasonable therapeutic option regardless of whether common bile duct stones are present at the time of ERCP. A prospective trial is needed to examine this issue since to date there is no literature on endoscopic sphincterotomy in the absence of choledocholithiasis for gallstone pancreatitis in patients with intact gallbladders.

Safety of same-day sequential extracorporeal shock wave lithotripsy and dissolution of gallstones by methyl tert-butyl ether in dogs

Passage of stone fragments after extracorporeal shock wave lithotripsy (ESWL) of gallstones has resulted in biliary colic, duct obstruction, and pancreatitis in some patients. Rapid dissolution of these fragments with methyl tert-butyl ether (MTBE) may prevent such side effects and achieve complete clearance of gallstones within hours rather than several months to a year or longer. This study examines the safety of same-day ESWL fragmentation and MTBE dissolution of surgically implanted human gallstones in 15 dogs. The animals were randomly assigned to one of four treatment groups to assess MTBE absorption from the gallbladder and to observe hematology and chemistry profiles after 0, 400, and 1,200 shock waves from a lithotriptor followed by MTBE dissolution therapy. They were sacrificed either immediately after treatment (12 dogs) or 2 weeks later (3 dogs). The results demonstrated that although ESWL causes moderate trauma to the gallbladder, this did not result in increased MTBE absorption or histologic evidence of mucosal disruption. Blood profiles demonstrated an increase in only the level of aspartate aminotransferase. The three dogs that were sacrificed 2 weeks after the combined treatment had no residual evidence of gallbladder injury or remaining stone material. In all animals, severe injury occurred where shock waves passed through lung or air-filled colon. This study suggests that same-day sequential fragmentation of gallstones by ESWL followed by dissolution of stone fragments with use of MTBE may be associated with only mild to moderate and reversible gallbladder trauma and can rapidly achieve clearance of gallstones.

Radioisotopic model for investigating thromboembolism in the rabbit

111Indium (111In)-oxine labeled platelets have been used in a variety of species to assess platelet behavior in vivo. We have shown that 111In-oxine is a suitable label for rabbit platelets and, using a noninvasive technique for the automated, continuous, external imaging of these radiolabeled platelets, we have shown that intravenous adenosine disphosphate (ADP), collagen, platelet activating factor (PAF), and thrombin all elicit dose-related accumulation of platelet-(but not erythrocyte-)associated radioactivity in the thoracic region and a concomitant fall in both the cranial and hindlimb regions of the anesthetized rabbit. Intracarotid (i.c.) ADP, collagen, PAF, and thrombin also produce dose-related increases in platelet-associated radioactivity in the thoracic and decreases in the cranial and hindlimb regions. However, the initial fall in cranial counts induced by i.c. thrombin was followed by a marked increase that was sustained for up to 3 hr. These results suggest this may be a useful model for investigating the mechanisms of platelet activation in the arterial and venous circulations in vivo and may provide a novel model for investigating thromboembolic events in the cerebral circulation.

Endothelin-1 inhibits platelet aggregation in vivo: a study with 111indium-labelled platelets

1. A non-invasive technique for the scintigraphic determination of 111indium-labelled platelet aggregation stimulated with submaximal doses of adenosine diphosphate (ADP, 56 micrograms kg-1 i.v.), collagen (100 micrograms kg-1 i.v.), platelet-activating factor (PAF, 0.1 microgram kg-1 i.v.) or thrombin (18 iu kg-1 i.v.) was used to investigate the platelet-inhibitory effects of endothelin 1 (ET-1) in anaesthetized rabbits in vivo. 2. ET-1 (1 nmol kg-1 i.v.) inhibited ADP-stimulated platelet aggregation in vivo; a maximum inhibition of 78% of the control value was reached at 3 min, with 45% inhibition at 15 min, and a return to control values at 30 min after injection of the peptide. 3. ET-1 (1 nmol kg-1 i.v.) inhibited in vivo platelet aggregation in response to collagen or PAF by 86% and 52%, respectively, but had no effect on thrombin-induced platelet aggregation. 4. Indomethacin (5 mg kg-1 i.v.) abolished the ET-1-induced inhibition of ADP-stimulated platelet aggregation and significantly potentiated and prolonged the pressor response brought about by ET-1. 5. In conclusion, the data demonstrate that ET-1 potently inhibits platelet aggregation in the anaesthetized rabbit in vivo by releasing a hypotensive and anti-aggregatory cyclo-oxygenase product, presumably prostacyclin, into the circulation.