Andreas Adler

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.

Narrow-Band Versus White-Light High Definition Television Endoscopic Imaging for Screening Colonoscopy: A Prospective Randomized Trial

BACKGROUND & AIMS Narrow-band imaging (NBI) has been implemented in gastrointestinal endoscopy to improve the contrast of endoluminal pathologic structures, one of the aims being to increase colonic adenoma detection. Previous studies from referral centers have yielded variable and conflicting results with regard to improvement in adenoma detection rates by using NBI. The present large randomized trial was designed to finally settle this issue. METHODS In a prospective study performed exclusively in a multicenter private practice setting involving 6 examiners with substantial lifetime experience (>10,000 colonoscopies), 1256 patients (men:women, 47%:53%; mean age, 64.4 y) were randomized to HDTV screening colonoscopy with either NBI or white-light imaging on instrument withdrawal. The primary outcome measure was the adenoma detection rate (ie, number of adenomas/total number of patients). RESULTS There was no difference between the 2 groups in terms of the general adenoma detection rate (0.32 vs 0.34), the total number of adenomas (200 vs 216), or in detection in subgroups of adenomas. This was despite a minimal, but significantly longer, withdrawal time in the NBI group (8.5 vs 7.9 min; P < .05). Only hyperplastic polyps were found more frequently in the NBI group (P = .03). CONCLUSIONS This large randomized trial in a homogeneous private practice screening setting could not show any objective advantage of the NBI technique over white-light high definition television imaging in terms of improved adenoma detection rate. Contrast enhancement therefore likely will not contribute to a reduction in adenoma miss rates among experienced colonoscopists.

Factors determining the quality of screening colonoscopy: a prospective study on adenoma detection rates, from 12 134 examinations (Berlin colonoscopy project 3, BECOP-3)

Background Screening colonoscopy (SC) outcome quality is best determined by the adenoma detection rate (ADR). The substantial variability in the ADRs between endoscopists may reflect different skills, experience and/or equipment. Objective To analyse the potential factors that may influence ADR variance, including case volume. Design 12 134 consecutive SCs (mean age 64.5 years, 47% men) from 21 Berlin private-practice colonoscopists were prospectively studied during 18 months. The data were analysed using a two-level mixed linear model to adequately address the characteristics of patients and colonoscopists. The ADR was regressed after considering the following factors: sex, age, bowel cleanliness, NSAID intake, annual SC case volume, lifetime experience, instrument withdrawal times, instrument generations used, and the number of annual continuing medical education (CME) meetings attended by the physician. The case volume was also retrospectively analysed from the 2007 national SC registry data (312 903 colonoscopies and 1004 colonoscopists). Results The patient factors that correlated with the ADR were sex, age (p<0.001) and low quality of bowel preparation (p=0.005). The factors that were related to the colonoscopists were the number of CME meetings attended (p=0.012) and instrument generation (p=0.001); these factors accounted for approximately 40% of the interphysician variability. Within a narrow range (6–11 min), the withdrawal time was not correlated with the ADR. Annual screening case volume did not correlate with the ADR, and this finding was confirmed by the German registry data. Conclusions The outcome quality of screening colonoscopies is mainly influenced by individual colonoscopist factors (ie, CME activities) and instrument quality. Clinical trial registration number Clinical Trial Gov Registration number: NCT00860665.

Clinical relevance of transabdominal ultrasonography and magnetic resonance imaging in patients with inflammatory bowel disease of the terminal ileum and large bowel.

Background:Ileocolonoscopy represents the diagnostic standard in the work-up of patients with inflammatory bowel diseases (IBD). Patients are often reluctant to be colonoscoped because of the invasiveness and pain sensation during colonoscopy. Aims:To compare the usefulness of transabdominal ultrasound (US) and magnetic resonance imaging (MRI) in assessing disease extension and activity in patients with IBD restricted to the terminal ileum and large bowel. Patients and Methods:61 patients with IBD [37 Crohns disease (CD) and 24 ulcerative colitis (UC)] were prospectively studied. All patients underwent clinical and laboratory assessment, ileocolonoscopy, transabdominal sonography, and MRI within 5 days. Involved bowel segments were defined as those with bowel wall thickness >3 mm and increased Doppler signal on US or contrast enhancement of the bowel wall on MRI. To compare disease activity endoscopic, MRI and US findings were graded with newly developed scores. Results:The segment-by-segment analysis revealed an overall accuracy of 89% for US and 73% for MRI in identifying active IBD. The accuracy was better in patients with UC than in patients with CD for both US and MRI. The endoscopic activity index (EAI) correlated stronger with the US activity index (r = 0.884) than with the MRI activity index (r = 0.344). The correlation of US and MRI activity indices with EAI was better in patients with UC compared with patients with CD. All three imaging methods showed a significant correlation with clinical disease activity in patients with UC but not in patients with CD. Conclusion:This study provides strong evidence that US should be considered as a first-choice method for follow-up of patients with IBD of the terminal ileum and large bowel.

Live Image Processing Does Not Increase Adenoma Detection Rate During Colonoscopy: A Randomized Comparison Between FICE and Conventional Imaging (Berlin Colonoscopy Project 5, BECOP-5)

OBJECTIVES:Fujinon intelligent chromoendoscopy (FICE) is a post-processing imaging technique for increasing contrast of mucosa and mucosal lesions that might lead to improvement in colonic adenoma detection during colonoscopy. Previous studies on similar contrast-enhancing techniques as well as on dye staining have yielded variable and conflicting results. This large randomized trial was undertaken to determine whether FICE technology enhances adenoma detection rate (ADR).METHODS:In a prospective study performed in a multicenter private practice and hospital setting, involving 8 examiners with substantial lifetime experience (>10,000 colonoscopies each), 1,318 patients (men 46.7%, women 53.3%; mean age 59.05 years) were randomly assigned to colonoscopy with either FICE or white light imaging on instrument withdrawal. Of the colonoscopies, 68% were screening and 32% were diagnostic examinations. The primary outcome measure was the ADR (i.e., number of adenomas/total number of patients).RESULTS:There was no difference between the two groups in terms of general ADR (0.28 in both groups), the total number of adenomas (184 vs. 183), or detection of subgroups of adenomas. The rate of identification of hyperplastic polyps was also the same in both groups (127 vs. 121; P=0.67). The results were the same for both the screening and the diagnostic colonoscopy subgroups. Withdrawal time was the same in both groups (8.4 vs. 8.3 min, P=0.55).CONCLUSIONS:This large randomized trial could not show any objective advantage of the FICE technique over conventional high-resolution endoscopy in terms of improved ADR.

Improving compliance to colorectal cancer screening using blood and stool based tests in patients refusing screening colonoscopy in Germany

BackgroundDespite strong recommendations for colorectal cancer (CRC) screening, participation rates are low. Understanding factors that affect screening choices is essential to developing future screening strategies. Therefore, this study assessed patient willingness to use non-invasive stool or blood based screening tests after refusing colonoscopy.MethodsParticipants were recruited during regular consultations. Demographic, health, psychological and socioeconomic factors were recorded. All subjects were advised to undergo screening by colonoscopy. Subjects who refused colonoscopy were offered a choice of non-invasive tests. Subjects who selected stool testing received a collection kit and instructions; subjects who selected plasma testing had a blood draw during the office visit. Stool samples were tested with the Hb/Hp Complex Elisa test, and blood samples were tested with the Epi proColon® 2.0 test. Patients who were positive for either were advised to have a diagnostic colonoscopy.Results63 of 172 subjects were compliant to screening colonoscopy (37%). 106 of the 109 subjects who refused colonoscopy accepted an alternative non-invasive method (97%). 90 selected the Septin9 blood test (83%), 16 selected a stool test (15%) and 3 refused any test (3%). Reasons for blood test preference included convenience of an office draw, overall convenience and less time consuming procedure.Conclusions97% of subjects refusing colonoscopy accepted a non-invasive screening test of which 83% chose the Septin9 blood test. The observation that participation can be increased by offering non-invasive tests, and that a blood test is the preferred option should be validated in a prospective trial in the screening setting.

Successful infliximab treatment of steroid and OKT3 refractory acute cellular rejection in two patients after intestinal transplantation

Acute rejection resistant to established immunosuppressive rescue protocols remains the most prominent risk factor after intestinal transplantation. In two patients presenting with steroid-resistant severe acute cellular rejection 9 months and 2 years after intestinal transplantation, complete resolution was not achieved despite 5 and 10 days of OKT3 treatment, respectively, and high-dose triple baseline immunosuppression with tacrolimus, rapamycin, and steroids. There was a dissociated course of rejection with persistent moderate to severe rejection in the terminal portion of the graft despite complete recovery from rejection in the proximal parts. Both patients were treated with four subsequent infusions of infliximab (3 mg/kg body weight), a chimeric anti-tumor necrosis factor-&agr; antibody. There was an immediate response regarding macroscopic appearance, graft histology, and clinical symptoms. Both patients recovered. In conclusion, infliximab has proven to be an effective rescue therapy in a selected group of patients with steroid and OKT3 refractory severe acute rejection after intestinal transplantation.

Long-term recurrence of neoplasia and Barrett's epithelium after complete endoscopic resection

Background Current endoscopic therapy for neoplastic Barretts oesophagus (BO) consists of complete resection/ablation of all Barretts tissue including neoplastic lesions. Recurrence seems to be frequent after thermal therapy, such as radiofrequency ablation. Objective To analyse long-term recurrence of neoplasia and BO after successful widespread endoscopic mucosal resection (EMR). Design In a retrospective analysis, all patients undergoing widespread EMR of neoplastic BO between 2002 and 2007 at two referral centres were followed for at least 3 years after completion of endotherapy. Recurrence was diagnosed if neoplasia and/or BO were detected following previous successful complete removal, defined as at least two negative endoscopies and biopsies. Results Ninety patients undergoing widespread EMR were included (mean age 63 years; 82 male), 58% of whom underwent additional thermal ablation for minor residual disease. Complete eradication of neoplasia and Barretts tissue was achieved in 90% of patients. On further follow-up (mean 64.8 months), recurrence of neoplastic and non-neoplastic BO was found in 6.2% and 39.5%, respectively. Recurring neoplasia (3 adenocarcinomas, 1 low-grade and 1 high-grade dysplasia) were found after a median of 44 months (range 38–85) and could be retreated endoscopically. In a multivariate analysis, Barretts length was the only factor significantly associated with recurrence (OR 2.73). Conclusions Even after seemingly complete endoscopic resection, recurrence of BO is frequent and independent of additional thermal therapy. Due to the possibility of neoplasia recurrence even after long disease-free intervals, follow-up should be extended beyond 5 years.

Endosonographic large-bore biopsy of gastric subepithelial tumors: a prospective multicenter study.

Background Once gastric subepithelial lesions (SEL) are found, tissue diagnosis is required, considering the possible differential diagnosis of gastrointestinal stromal tumors (GIST). Previous studies have shown insufficient accuracy of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using cytologic analysis. Methods The feasibility and yield of EUS–FNA-based histologic tissue acquisition for gastric SEL, using 19 G large-bore needles, was assessed in a 4-year multicenter, prospective study. All consecutive patients, who were referred for EUS–FNA for all SEL greater than 1 cm, were included. Results Of 100 patients with suspected gastric SEL, 71 lesions were found to be eligible. Endoscopic biopsies or resections or surgery were used alternatively for a variety of reasons in 25 patients. EUS–FNA using the 19 G needle was finally performed in 46/71 cases (65%) with one to four needle passes. Sufficient material for a definite or a suspected histological diagnosis was obtained in 52 and 7% of the cases, respectively. In 41%, the samples were not informative. Immunohistochemistry was possible in 91% of cases with sufficient amounts of tissue; 30% were GIST. Self-limited, mild hemorrhage occurred in 22%; one patient developed a fatal abscess. Conclusion Even when intended, EUS-guided 19 G FNA is only feasible in 46% of gastric SEL. The diagnostic yield of 19 G FNA was only 52%, but with excellent differentiation between GIST and leiomyoma. Infectious complications must be prevented.

Latest Generation, Wide-Angle, High-Definition Colonoscopes Increase Adenoma Detection Rate

BACKGROUND & AIMS Improvements to endoscopy imaging technologies might improve detection rates of colorectal cancer and patient outcomes. We compared the accuracy of the latest generation of endoscopes with older generation models in detection of colorectal adenomas. METHODS We compared data from 2 prospective screening colonoscopy studies (the Berlin Colonoscopy Project 6); each study lasted approximately 6 months and included the same 6 colonoscopists, who worked in private practice. Participants in group 1 (n = 1256) were all examined by using the latest generation of wide-angle, high-definition colonoscopes that were manufactured by the same company. Individuals in group 2 (n = 1400) were examined by endoscopists who used routine equipment (a mixture of endoscopes from different companies; none of those used to examine group 1). The adenoma detection rate was calculated on the basis of the number of all adenomas/number of all patients. RESULTS There were no differences in patient parameters or withdrawal time between groups (8.0 vs 8.2 minutes). The adenoma detection rate was significantly higher in group 1 (0.33) than in group 2 (0.27; P = .01); a greater number of patients with least 1 adenoma were identified in group 1 (22.1%) than in group 2 (18.2%; P = .01). A higher percentage of high-grade dysplastic adenomas were detected in group 1 (1.19%) than in group 2 (0.57%), but this difference was not statistically significant (P = .06). CONCLUSIONS The latest generation of wide-angle, high-definition colonoscopes improves rates of adenoma detection by 22%, compared with mixed, older technology endoscopes used in routine private practice. These findings might affect definitions of quality control parameters for colonoscopy screening for colorectal cancer.