Endoscopic characterization of colorectal neoplasia with different published classifications: comparative study involving CONECCT classification.

Background and study aims The aim of this study was to validate the COlorectal NEoplasia Classification to Choose the Treatment (CONECCT) classification that groups all published criteria (including covert signs of carcinoma) in a single table. Patients and methods For this multicenter comparative study an expert endoscopist created an image library (n = 206 lesions; from hyperplastic to deep invasive cancers) with at least white light Imaging and chromoendoscopy images (virtual ± dye based). Lesions were resected/biopsied to assess histology. Participants characterized lesions using the Paris, Laterally Spreading Tumours, Kudo, Sano, NBI International Colorectal Endoscopic Classification (NICE), Workgroup serrAted polypS and Polyposis (WASP), and CONECCT classifications, and assessed the quality of images on a web-based platform. Krippendorff alpha and Cohen's Kappa were used to assess interobserver and intra-observer agreement, respectively. Answers were cross-referenced with histology. Results Eleven experts, 19 non-experts, and 10 gastroenterology fellows participated. The CONECCT classification had a higher interobserver agreement (Krippendorff alpha = 0.738) than for all the other classifications and increased with expertise and with quality of pictures. CONECCT classification had a higher intra-observer agreement than all other existing classifications except WASP (only describing Sessile Serrated Adenoma Polyp). Specificity of CONECCT IIA (89.2, 95 % CI [80.4;94.9]) to diagnose adenomas was higher than the NICE2 category (71.1, 95 % CI [60.1;80.5]). The sensitivity of Kudo Vi, Sano IIIa, NICE 2 and CONECCT IIC to detect adenocarcinoma were statistically different ( P  < 0.001): the highest sensitivities were for NICE 2 (84.2 %) and CONECCT IIC (78.9 %), and the lowest for Kudo Vi (31.6 %). Conclusions The CONECCT classification currently offers the best interobserver and intra-observer agreement, including between experts and non-experts. CONECCT IIA is the best classification for excluding presence of adenocarcinoma in a colorectal lesion and CONECCT IIC offers the better compromise for diagnosing superficial adenocarcinoma.

A simplified table using validated diagnostic criteria is effective to improve characterization of colorectal polyps: the CONECCT teaching program.

Introduction and study aims Accurate real-time endoscopic characterization of colorectal polyps is key to choosing the most appropriate treatment. Mastering the currently available classifications is challenging. We used validated criteria for these classifications to create a single table, named CONECCT, and evaluated the impact of a teaching program based on this tool. Methods A prospective multicenter study involving GI fellows and attending physicians was conducted. During the first session, each trainee completed a pretest consisting in histological prediction and choice of treatment of 20 colorectal polyps still frames. This was followed by a 30-minute course on the CONECCT table, before taking a post-test using the same still frames reshuffled. During a second session at 3 - 6 months, a last test (T3 M) was performed, including these same still frames and 20 new ones. Results A total 419 participants followed the teaching program between April 2017 and April 2018. The mean proportion of correctly predicted/treated lesions improved significantly from pretest to post-test and to T3 M, from 51.0 % to 74.0 % and to 66.6 % respectively ( P  < 0.001). Between pretest and post-test, 343 (86.6 %) trainees improved, and 153 (75.4 %) at T3 M. Significant improvement occurred for each subtype of polyp for fellows and attending physicians. Between the two sessions, trainees continued to progress in the histology prediction and treatment choice of polyps CONECCT IIA. Over-treatment decreased significantly from 30.1 % to 15.5 % at post-test and to 18.5 % at T3 M ( P  < 0.001). Conclusion The CONECCT teaching program is effective to improve the histology prediction and the treatment choice by gastroenterologists, for each subtype of colorectal polyp.

Impact of 2 generational improvements in colonoscopes on adenoma miss rates: results of a prospective randomized multicenter tandem study.

BACKGROUND AND AIMS: Numerous randomized studies have shown that changing certain features of colonoscopes, usually incorporated when switching from one endoscope generation to the next, mostly do not increase adenoma yield. There is, however, indirect evidence that it may be necessary to skip one instrument generation (ie, changing from one generation to the next but one) to achieve this effect. METHODS: We compared the latest-generation colonoscopes from one company (Olympus Exera III, 190-C) with the next to last one (Olympus 160/5-C) in a prospective multicenter study randomized for the order of colonoscopes in a tandem fashion, involving 2 different examiners. Patients with increased risk for colorectal neoplasia undergoing colonoscopy (positive fecal occult blood test, personal/familial history of colorectal cancer/adenoma, rectal bleeding, recent change in bowel movements) were included. The primary outcome was the adenoma miss rate with the 190 (190-C) colonoscope in comparison with the 160/5 colonoscope (160/5-C). RESULTS: A total of 856 patients (48.8% male; mean age, 58.3 years) with a personal (41%) or family (38%) history of colorectal neoplasia, rectal bleeding (19%), and other indications were included. Of the 429 patients in the 190-C first group, 16.6% (95% confidence interval [CI], 13.0%-20.1%) had at least one adenoma missed during the first procedure, compared with 30.2% (95% CI, 25.9%-34.6%) in the group with 160/5-C first (P < .001). Similarly, the adenoma detection rate during the first colonoscopy was 43.8% versus 36.5% (P = .030) for 190-C versus 160/5-C, respectively. CONCLUSIONS: This randomized tandem trial showed lower adenoma miss rates and higher adenoma detection rates for the newer 190 colonoscopes compared with the 160/5 series. These results suggest that it takes multiple improvements, such as those implemented over 2 instrument generations, before an effect on adenoma (miss) rate can be observed. (Study registration number: ISRCTN 2010-A01256-33.).

A self-assembling matrix-forming gel can be easily and safely applied to prevent delayed bleeding after endoscopic resections.

BACKGROUND: Endoscopic resections have low morbidity and mortality. Delayed bleeding has been reported in approximately 1 - 15 % of cases, increasing with antiplatelet/anticoagulant therapy or portal hypertension. A self-assembling peptide (SAP) forming a gel could protect the mucosal defect during early healing. This retrospective trial aimed to assess the safety and efficacy of SAP in preventing delayed bleeding after endoscopic resections. METHODS: Consecutive patients with endoscopic resections were enrolled in two tertiary referral centers. Patients with a high risk of bleeding (antiplatelet agents, anticoagulation drugs with heparin bridge therapy, and cirrhosis with portal hypertension) were also included. The SAP gel was applied immediately after resection to cover the whole ulcer bed. RESULTS: In total, 56 patients were included with 65 lesions (esophagus [n = 8], stomach [n = 22], duodenum [n = 10], ampullary [n = 3], colon [n = 7], and rectum [n = 15]) in two centers. Among those 65 lesions, 29 were resected in high risk situations (9 uninterrupted aspirin therapy, 6 heparin bridge therapies, 5 cirrhosis and portal hypertension, 1 both cirrhosis and heparin bridge, 3 both cirrhosis and uninterrupted aspirin, 3 large duodenal lesions > 2 cm, and 2 early introduction of clopidogrel at day 1). The resection technique was endoscopic submucosal dissection (ESD) in 40 cases, en bloc endoscopic mucosal resection (EMR) in 16, piecemeal EMR in 6, and ampullectomy in 3. The mean lesion size was 37.9 mm (SD: 2.2 mm) with a mean area of 6.3 cm(2) (SD: 3.5 cm(2)). No difficulty was noted during application. Four delayed overt bleedings occurred (6.2 %) (3 hematochezia, 1 hematemesis) requiring endoscopic hemostasis. The mean hemoglobin drop off was 0.6 g/dL (- 0.6 to 3.1 g/dL). No adverse events occurred. CONCLUSION: The use of this novel extracellular matrix scaffold may help to reduce post-endoscopic resection bleedings including in high risk situations. Its use is easy and safe but further comparative studies are warranted to completely evaluate its effectiveness.

High pressure jet injection of viscous solutions for endoscopic submucosal dissection (ESD): first clinical experience.

BACKGROUND: Long lasting elevation is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water jet injection of saline solution or by viscous macromolecular solutions. In a previous animal study, we assessed the Nestis Enki II system to combine jet injection and viscous solutions. In the present work, we used this combination in humans in different sites of the digestive tract. METHODS: We retrospectively report all of the consecutive ESD procedures performed with jet injection of viscous solutions in four centers. Information was collected about the lesion, the procedure, the histological result, and the outcomes for the patient. RESULTS: In total, 45 resections were completed by six operators: five experts and one beginner with only one previous experience in human ESD. Lesions were located in the esophagus (10), the stomach (11), the duodenum (1), the colon (1) and the rectum (22). Average maximal lesion diameter was 4.8 cm (SD 2.4, range 2 - 11 cm), average lesion surface area was 19.8 cm(2) (SD 17.7, range 2.2 - 72 cm(2)), and average duration of procedure was 79.9 min (SD 50.3 min, range 19 - 225 min). ESD could be conducted while the endoscope was retroflexed at its maximum in 26 cases. Four adverse events were observed: two diminutive perforations and two delayed bleeding occurrences treated conservatively. The R0 resection rate was 91.1 %. The catheter was obstructed in six occurrences of bleeding. CONCLUSION: Endoscopic submucosal dissection using high pressure injection of viscous macromolecular solutions is safe and effective in different parts of the digestive tract. It does not impede working with the endoscope in the maximal retroflexed position.

High-pressure jet injection of viscous solutions for endoscopic submucosal dissection: a study on ex vivo pig stomachs.

BACKGROUND: Long-lasting lifting is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water-jet injection of saline solution or by injection of viscous macromolecular solutions. Combination of the jet injection and the macromolecular viscous solutions has never been used yet. We assessed the ability of a new water-jet system to inject viscous solutions in direct viewing and in retroflexion. We compared jet injection of saline solution and hyaluronate 0.5 % to perform ESD on ex vivo pig stomachs in order to evaluate the benefits of macromolecular solutions when injected by a jet-injector system. METHODS: This is a prospective comparative study in pig stomachs. Using the jet injector, four viscous solutions were tested: hydroxyethyl starch, glycerol mix, hyaluronate sodic (0.5 %), and poloxamer mix. Ten ESDs larger than 25 mm (five in direct viewing and five in retroflexion) and one larger than 10 cm were performed with each solution. ESD with hyaluronate jet injection was then compared with ESD with saline jet injection by performing 50 ESDs in each group. A single, minimally-experienced operator conducted all the procedures. RESULTS: All 145 resections were complete, including all marking points with two perforations. Eleven jet ESDs per solution were conducted without any injection issue. In the second part of the study, when compared with saline, significant benefit of hyaluronate was observed on dissection speed (0.80 vs. 1.08 cm(2)/min, p < 0.001). CONCLUSION: This is the first report on a jet-injector system allowing injection of macromolecular viscous solutions even with retroflexed endoscope. Jet injection of macromolecular solutions can speed up dissection in comparison with saline, and should now be tested on humans.