[Highlights in gastroenterology 2011]

«Gastro-Highlights», an annual symposium dedicated to continuing education, took place at the University Hospital Zürich for the sixteenth time this autumn. In this well-attended event, major new findings in the fields of gastroenterology and hepatology that were published in the past year or recently presented at the «Digestive Disease Week (DDW)» were summarized for practising gastroenterologists and internists.

Effectiveness of a novel endoscopy training concept

BACKGROUND AND STUDY AIMS

Training standards in gastrointestinal endoscopy are poorly defined even though different simulators are increasingly used for skills training. In 2001 a new training concept called "GATE--gastroenterological education-training endoscopy" was established, which provides a combination of background theory, video demonstrations, and simulator training. We aimed to evaluate the acceptance and training effect of this training model.

METHODS

In total, 98 physicians participating in four training courses were included. Data were collected on baseline characteristics, acceptance (5-point Likert scale), and pre- and post-course knowledge through a structured questionnaire (A-type and Pick-N multiple choice questions). A total of 13 trainees were randomly selected for additional simulator assessment of training effects on manual skills (5-point Likert scale).

RESULTS

A total of 78 trainees (80%) provided complete data sets. The evaluation showed a positive acceptance of the training program (value 1 and 2, Likert scale); for example, 88% of participants suggested the inclusion of the GATE course as an obligatory part of endoscopic education. There was a significant improvement in theoretical knowledge in the post-test set compared with the pre-test set (mean 3.27 ±1.30 vs. 1.69 ±1.01 points; P<0.001). The training effect on practical skill showed a significant reduction in time needed for a procedure (445 ±189 s vs. 274 ±129 s; P<0.01). The mean assessment rating for practical skills improved from 3.05 ±0.65 at baseline to 2.52 ±0.59 on Likert scale ( P=0.085).

CONCLUSIONS

The integrated GATE training improved theoretical knowledge and manual skill. The GATE courses have been accredited by the German Society of Gastroenterology, underlining the demand for implementing preclinical training courses in endoscopic training.

UEGW 2010 Report. Putting endoscopy into perspective

The 18th United European Gastroenterology Week (UEGW), held in Barcelona in October 2010, marked a return to the traditional "stand-alone" UEGW meeting after the previous year's combined congress format of GASTRO 2009. Various abstracts on endoscopic subjects were presented, providing a unique opportunity for those interested in gastrointestinal endoscopy to not only become acquainted with the latest advancements and research in the field, but also to meet and exchange experiences with colleagues from all over the world. This report will focus mainly on oral presentations, with a few selected poster presentations, which will be reviewed briefly in the context of recent literature in the respective fields of gastrointestinal endoscopy.

[Highlights in gastroenterology 2010]

This summer saw the fifteenth edition of «Gastro-Highlights», a well-attended symposium dedicated to continuing education that takes place each year at the University Hospital in Zurich. Major new findings in the fields of gastroenterology and hepatology that were achieved in the past year and were recently presented at the «Digestive Disease Week (DDW)» were summarized here for practising gastroenterologists and internists.

Neuroendocrine tumors of the stomach (gastric carcinoids) are on the rise: small tumors, small problems?

Well differentiated neuroendocrine tumors (NETs) of the stomach (gastric carcinoid tumors) are observed more often, with a tenfold increase in the US in the last 30 - 35 years, and the prognosis has improved greatly in that time. Nowadays most carcinoids of the stomach are diagnosed at an early stage. Four types of gastric NETs have been proposed and recognition of the type is important for defining the diagnostic approach and treatment. Often gastric NETs (especially type 1) are found incidentally during a gastroscopy performed for other reasons; most of these NETs are smaller than 20 mm in size. Conservative management and endoscopic surveillance is adequate for well differentiated, multifocal gastric carcinoids (type 1 or type 2 gastric NETs) that are less than 10 - 20 mm in diameter, unless they show angioinvasion, infiltrate the muscular wall, or have a proliferation rate above 2 %. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. It is essential to distinguish between multifocal (types 1 and 2) and unifocal type 3 or type 4 gastric NETs, since surgery is indicated for type 3 gastric NETs larger than 10 mm in diameter and for poorly differentiated (localized) neuroendocrine gastric carcinomas (type 4 gastric NET). For optimal management, the type, biology, and stage of the tumor as well as the individual situation of the patient must be considered. Most patients with well differentiated gastric NETs can be treated conservatively and be followed up with endoscopic surveillance.

Probe-based confocal laser endomicroscopy compared with standard four-quadrant biopsy for evaluation of neoplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS

Surveillance of Barrett's esophagus includes endoscopic inspection with biopsy of suspicious lesions followed by four-quadrant biopsy of the remaining mucosa. We assessed the ability of probe-based confocal laser endomicroscopy (pCLE) to replace biopsy in the endoscopic evaluation of patients with Barrett's esophagus in a prospective and controlled setting.

PATIENTS AND METHODS

A total of 68 patients who were referred for endoscopic assessment of Barrett's esophagus were included across three centers. pCLE recordings were interpreted live during the examination as well as in a blinded manner at least 3 months after endoscopy. pCLE diagnosis of neoplasia based on pre-defined criteria was compared with histopathology from suspicious as well as four-quadrant biopsies.

RESULTS

A total of 670 pairs of biopsies and pCLE video sequences were available for analysis, with neoplasia (high-grade dysplasia or cancer) being histologically diagnosed in 8.3 %. Specificity and negative predictive value of pCLE in excluding neoplasia was 0.97 (90 %CI 0.95 - 0.98) and 0.93 (0.91 - 0.95) for the blinded evaluation, and 0.95 (0.90 - 0.98) and 0.92 (0.90 - 0.94) for the on-site assessment. Positive predictive values (PPVs) and sensitivity were rather poor for both settings (46 %/28 % [blinded] and 18 %/12 % [on-site], respectively).

CONCLUSIONS

pCLE can be regarded as non-inferior to endoscopic biopsy in excluding neoplasia of Barrett's esophagus mucosa. However, due to its low PPV and sensitivity, pCLE may currently not replace standard biopsy techniques for the diagnosis of Barrett's esophagus and associated neoplasia. Further technical development of pCLE and a better understanding of its role in relation to other imaging technologies are necessary.

Transluminal endoscopic necrosectomy after acute pancreatitis: a multicentre study with long-term follow-up (the GEPARD Study)

BACKGROUND

As with endoscopic transmural drainage of peripancreatic fluid collections, the same transluminal access can be expanded to introduce an endoscope through the gastrointestinal wall into the retroperitoneum and remove infected pancreatic necroses under direct visual control. This study reports the first large series with long-term follow-up.

METHODS

Data for all patients undergoing transluminal endoscopic removal of (peri)pancreatic necroses between 1999 and 2005 in six different centres were collected retrospectively, and the patients were followed up prospectively until 2008. The initial patient and treatment outcome data were recorded, as were long-term results.

RESULTS

Ninety-three patients (63 men, 30 women; mean age 57 years) underwent a mean of six interventions starting at a mean of 43 days after an attack of severe acute pancreatitis. After establishment of transluminal access to the necrotic cavity and subsequent endoscopic necrosectomy, initial clinical success was obtained in 80% of the patients, with a 26% complication and a 7.5% mortality rate at 30 days. After a mean follow-up period of 43 months, 84% of the initially successfully treated patients had sustained clinical improvement, with 10% receiving further endoscopic and 4% receiving surgical treatment for recurrent cavities; 16% suffered recurrent pancreatitis.

CONCLUSIONS

Direct transluminal endoscopic removal of pancreatic necroses is associated with good long-term maintenance of the high initial efficacy; complications can occur, with an associated mortality of around 7.5%. Further studies are necessary in order to optimise endotherapy and define its role in relation to surgery in the clinical management of such patients.

UEGW Report 2008: putting endoscopy into perspective

The 16th United European Gastroenterology Week (UEGW), which was held in Vienna in October 2008, provided the opportunity for those interested in gastrointestinal endoscopy to be informed of the experience of colleagues throughout the world and to become acquainted with the latest advancements and research in the field. Many of these abstracts focused on innovations and new techniques, and numerous others concentrated on topics with an impact on everyday clinical practice. This report attempts to highlight mostly oral presentations but also a few selected poster presentations, and each will be briefly reviewed in the light of recent publications in the respective fields of gastrointestinal endoscopy.

Long-term follow-up of percutaneous transhepatic biliary drainage (PTBD) in patients with benign bilioenterostomy stricture

BACKGROUND AND AIMS

Anastomotic strictures are well-known complications after bilioenterostomy. Endoscopic procedures are usually not possible in patients with a bilioenterostomy. Hence, percutaneous transhepatic biliary drainage (PTBD) has become the treatment of choice for the management of these patients. The main goal of the present study was to analyze the long-term follow-up of PTBD in such patients.

METHODS AND PATIENTS

Between January 1996 and December 2006, 44 patients with benign anastomotic stricture after bilioenterostomy were identified by an analysis of the PTBD database, hospital charts, and cholangiograms.

RESULTS

In 27/44 patients the percutaneous transhepatic biliary drain was successfully removed after 19.9 +/- 16.1 months (treatment success in 61.4 %). During a mean follow-up of 53.7 +/- 28.4 months after removal of the drain, no evidence was found of recurrent strictures in these patients. Ten out of 44 patients carry permanent drains (22.6 % of patients with ongoing treatment, mean follow-up 46.4 +/- 54.7 months) without the option for further surgery owing to concomitant disease (n = 2) or because they refused further surgery (n = 8). In 7 out of 44 patients (16 %) PTBD treatment was deemed to have failed and the patients underwent repeat operation.

CONCLUSIONS

PTBD should be considered the treatment of choice in patients with benign anastomotic stricture after bilioenterostomy, especially after stricturing of a hepatojejunostomy.

[Impact of the body mass index on the prognosis and complication rate after surgical resection of cancers at the oesophagogastric junction]

BACKGROUND

An elevated body mass index (BMI) is associated with an increased incidence of cancer at the gastro-oesophageal junction. Less is known about the postoperative complication rate and prognosis in relation to the BMI.

PATIENTS AND METHODS

We investigated 108 patients with cancer of the cardia and a BMI below (group 1, n = 56) or above (group 2, n = 52) 25 kg / m (2), who were operated from 2000 to 2006 in our department. According to the Siewert classification, the tumours were subdivided into 3 types. Patients with type I cancers (n = 26) received a transthoracic oesophageal resection with gastric pull up. Patients with type II (n = 61) or type III (n = 21) cancers underwent an extended gastrectomy. The complication rates and survival were analysed.

RESULTS

The complications were pulmonary (respiratory insufficiency n = 12, pneumonia n = 12, bronchitis n = 7, pulmonary embolism n = 2), surgical (anastomotic leakage n = 7, abscesses n = 8, bleeding n = 2, chylus fistula n = 1), or functional (dysphagia n = 5, nausea n = 5, heart burn n = 4, delayed enteral passage n = 6, vomiting n = 9). Patients of group 2 showed more delayed enteral passages (5 vs. 1) and more vomiting (7 vs. 2) than those of group 1. The median stay in the intensive care unit was shorter in group 1 than in group 2 (3 vs. 5 days) (p = 0.021). Overall hospitalisation was 14 days in the mean in both groups. We found no significant difference in the postoperative mortality of 6.5 % (n = 7) between the two groups. Overall survival after a follow-up of 42 months was 34 % (group 1) and 25 % (group 2). The difference did not reach statistical significance (p = 0.961). Patients with an elevated BMI show slightly more complications than those with a lower BMI.

CONCLUSIONS

Our data show that patients with elevated BMI have slightly more complications and an identical long term survival as patients with normal body weight.

Miniprobe confocal laser microscopy for the detection of invisible neoplasia in patients with Barrett's oesophagus

OBJECTIVE

The biggest challenge in endoscopic surveillance of Barrett's oesophagus is better detection of neoplasia in mucosa of normal macroscopic appearance. We evaluated in vivo miniprobe confocal laser microscopy (CLM) for the detection of invisible Barrett's neoplasia.

DESIGN

Prospective two-centre trial in two phases: phase I to establish criteria of Barrett's neoplasia and phase II to test these criteria.

PATIENTS AND INTERVENTION

296 biopsy sites in 38 consecutive patients with Barrett's oesophagus (mean age 62.1 years, 89.5% men, median length of the Barrett's oesophagus, 3 cm) were examined with standard high-resolution endoscopy and by miniprobe CLM, with precise matching of CLM recordings to biopsy sites. CLM image criteria for normal versus neoplastic Barrett's oesophagus were established from 95 biopsies of 15 patients (phase I); these criteria were then prospectively tested on 201 biopsies from the remaining patients without visible focal changes (phase II). All 201 CLM video recordings from phase II cases were randomised and blindly evaluated by two gastroenterologists.

MAIN OUTCOME MEASURE

The primary endpoints were accuracy values in diagnosing HGIN or early carcinoma (EC) on a per-biopsy basis. Secondary endpoints included inter-observer agreement.

RESULTS

All initially defined miniprobe CLM criteria (phase I) were significantly more frequently detected in HGIN/EC sites compared with sites with no or low grade neoplasia (phase II). In a per-biopsy analysis, sensitivity and specificity for two independent investigators were 75.0% and 88.8%, and 75.0% and 91.0%, respectively, translating at best into a positive predictive value of 44.4% and a negative predictive value of 98.8%. Inter-observer agreement was good (kappa 0.6).

CONCLUSION

Miniprobe CLM showed a high negative predictive value for the diagnosis of endoscopically invisible neoplasia in Barrett's oesophagus; sensitivity, however, has still to be improved.

Critical reappraisal of current surveillance strategies for Barrett's esophagus: analysis of a large German Barrett's database

Endoscopic surveillance is recommended for patients with Barrett's esophagus (BE). Based on a large database, gathered from predominantly community-based practices in Germany, we aimed to investigate the time-course of malignant progression and apply these findings to current clinical practice. Data of 1438 patients with BE from a large German BE database were analyzed. Patients with at least one follow-up endoscopy/biopsy were included. Detection of 'malignant Barrett' (either high-grade intra-epithelial neoplasia or invasive adenocarcinoma) was considered as study end-point. Of 1438 patients with BE, 57 patients had low-grade intra-epithelial neoplasia (LG-IN) on initial biopsy and 1381 exhibited non-neoplastic BE. 'Malignant Barrett' was detected in 28 cases (1.9%) during a median follow-up period of 24 months (1-255), accounting for an incidence of 0.95% per patient year of follow-up. The frequency of 'malignant Barrett' was significantly higher (P < 0.001, chi(2)-test) in the LG-IN group (n = 11, 19.3%) compared with the non-neoplastic BE group (n = 17, 1.2%). In the non-neoplastic BE group, 'malignant Barrett' was predominantly found during re-endoscopy within the first year of follow-up (12 of 17; 70.6%), in contrast to the LG-IN group, in which 'malignant Barrett' was observed predominantly after a time exceeding 12 months (8 of 11, 72.7%; P = 0.05, Fisher's exact test). Initial endoscopic evaluations seem to play the most crucial role in managing BE. After 1 year of follow-up, endoscopic surveillance should be focused on patients with LG-IN. In patients with repeatedly proven non-neoplastic BE, elongation of the follow-up intervals to the upper limit of current guidelines, that is, 5 years, might be justified.

Endoscopy in Barrett's oesophagus: adherence to standards and neoplasia detection in the community practice versus hospital setting

OBJECTIVE

Potential process differences between hospital and community-based endoscopy for Barrett's oesophagus have not been examined. We aimed at comparing adherence to guidelines and neoplasia detection rates in medical centres (MC) and community practices (CP).

DESIGN

Retrospective analysis.

SETTING

All histologically confirmed Barrett cases seen over a 3-year period in six MC and 19 CP covering a third of all upper gastrointestinal endoscopies (n = 126,000) performed annually in Berlin, Germany.

MAIN OUTCOME MEASURE

Rate of relevant neoplasia (high-grade intraepithelial neoplasia or more) in both settings in relation to adherence to standards.

RESULTS

Of 1317 Barrett cases, 66% were seen in CP. CP patients had a shorter mean Barrett length (2.6 cm vs. 3.8 cm; P < 0.001) with fewer biopsies taken during an examination (2.5 vs. 4.1 for Barrett length <or=2 cm; P < 0.001). CPs also provided fewer complete esophagogastroduodenoscopy documentation (25.1% vs. 57.8%, P < 0.001). Neoplasias were found more commonly in MCs compared to CPs (9.2% vs. 0.8%; P < 0.001). However, on exclusion of all referred patients with known neoplasia (65%) or those examined for other reasons (27.5%), the detection rate at MCs decreased to 1.3%, not different from the one seen at CPs (0.8%, P = 0.43). Only 13% were found during surveillance, but 57% were diagnosed at an early stage.

CONCLUSIONS

Referral bias and not better adherence to guidelines could explain the higher neoplasia prevalence in Barrett's oesophagus at hospital centres. Despite a generally poor adherence to guidelines, most neoplasias found were at an early and potentially curable stage.

A novel and practicable ERCP training system with simulated fluoroscopy

INTRODUCTION

Simulators facilitate the acquisition of technical skills for endoscopy. Here, we describe the development, introduction, and first evaluation of a novel generation of mechanical endoscopic retrograde cholangiopancreatography (ERCP) simulation models with simulated fluoroscopy, the X-Vision ERCP Training System.

METHODS

A custom-made modular ERCP simulation system was built with the use of universally obtainable materials and tools. The trainee controls ERCP activities on two screens: the aspect of the papilla and duodenum is shown on the conventional endoscopy monitor, and the trainee's actions in the equivalents of the pancreaticobiliary ducts are shown on the viewing screen of the model. Thereby, the latter screen serves as a substitute for fluoroscopy. Currently, four different models are available, allowing simulation of selective cannulation of the pancreatic or bile duct, intubation of differently arranged papillae, stent placement, and sphincterotomy of a biopapilla. The X-Vision ERCP Training System was first used during an ERCP course attended by 26 endoscopists. Trainees were supervised by an ERCP expert and an experienced ERCP nurse at each training model. The training system was evaluated by the participants and experts using a specific questionnaire.

RESULTS

During the course there were no technical problems related to the X-Vision ERCP Training System. After sphincterotomy the organic papillae could easily be exchanged within less than 15 seconds. Overall, the X-Vision ERCP Training System achieved favorable results in all categories assessed.

CONCLUSION

The new X-Vision ERCP Training System is simple and effective. A first evaluation in the context of an ERCP course showed impressive results.

The new scopes--broadening the colonoscopy marketplace

Colonoscopy has been established as a screening tool for colorectal cancer and precursors in some countries. Efforts to improve instrument performance as well as patient comfort, safety and compliance have led to modifications of existing endoscopes as well as to the development of new scopes with different working mechanisms, including the colon capsule. While the former have not substantially changed performance, the true value of new scopes - partially single use and/or self propelling - can not be fully assessed, since they are either still under development and/or tested only in animals and in small groups of patients or volunteers. The colon capsule holds promise but has a too complicated preparatory regimen and too low a sensitivity at the moment. Future developments and further studies will show which of these techniques may complement or even replace traditional screening colonoscopy.

A prospective randomised study on narrow-band imaging versus conventional colonoscopy for adenoma detection: does narrow-band imaging induce a learning effect?

BACKGROUND AND AIMS

Colonoscopy is an established method of colorectal cancer screening, but has an adenoma miss rate of 10-20%. Detection rates are expected to improve with optimised visualisation methods. This prospective randomised study evaluated narrow-band imaging (NBI), a new technique that may enhance image contrast in colon adenoma detection.

METHODS

Eligible patients presenting for diagnostic colonoscopy were randomly assigned to undergo wide-angle colonoscopy using either conventional high-resolution imaging or NBI during instrument withdrawal. The primary outcome parameter was the difference in the adenoma detection rate between the two techniques.

RESULTS

A total of 401 patients were included (mean age 59.4 years, 52.6% men). Adenomas were detected more frequently in the NBI group (23%) than in the control group (17%) with a number of 17 colonoscopies needed to find one additional adenoma patient; however, the difference was not statistically significant (p = 0.129). When the two techniques were compared in consecutive subgroups of 100 study patients, adenoma rates in the NBI group remained fairly stable, whereas these rates steadily increased in the control group (8%, 15%, 17%, and 26.5%, respectively). Significant differences in the first 100 cases (26.5% versus 8%; p = 0.02) could not be maintained in the last 100 cases (25.5% versus 26.5%, p = 0.91).

CONCLUSIONS

The increased adenoma detection rate means of NBI colonoscopy were statistically not significant. It remains speculative as to whether the increasing adenoma rate in the conventional group may have been caused by a training effect of better polyp recognition on NBI.