Efficacy of early clip-with-line method for colorectal endoscopic submucosal dissection

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) remains demanding due to technical difficulties and high risk of perforation. Most of the reported traction methods are initiated after creating a mucosal flap, which is time consuming. To obtain a good visualization at the mucosal incision stage, we developed the early clip-with-line (ECL) method. This method was started immediately after injection of sodium hyaluronate solution into the submucosal layer. In this study, we evaluated the efficacy and the safety of the ECL method for colorectal ESD.

METHODS

We retrospectively analyzed all cases of colorectal ESDs (41 cases in total) performed from January 2017 to February 2019 in our institution. From January 2017 to August 2018, 27 of these cases were performed using conventional (non-ECL) ESDs, while from September 2018 onwards, the remaining 14 cases were performed using the ECL method. Retrospective comparison between the ECL group and the non-ECL group was conducted in terms of clinical characteristics, treatment outcomes, and adverse events.

RESULTS

There were no significant differences in clinical characteristics between two groups. Procedure time (median [range]) was significantly shorter in the ECL group than in the non-ECL group (66 [29-131] min vs 90 [30-410] min; P = 0.03). As for adverse events, no case of perforation occurred in the ECL group, whereas perforation was observed in 7.4% (2/27) cases in the non-ECL group (no significant difference).

CONCLUSION

Early clip-with-line method for colorectal endoscopic submucosal dissection reduced procedure time.

Linked color imaging improves the endoscopic visibility of gastric mucosal cancers

Background and study aims  As a newly developed endoscopy technique, linked color imaging (LCI) provides very bright images with enhanced color tones. With the objective of improving the detection rate of gastric mucosal cancers, which are often difficult to detect, we examined the utility of LCI from the viewpoint of visibility. Patients and methods  The current study used 100 consecutive gastric mucosal cancers ≤ 20 mm in diameter. For each lesion, we selected one endoscopic image acquired by white-light imaging (WLI), blue-laser imaging (BLI) -bright, and LCI modes. Four endoscopists interpreted the images; using a previously reported scale, we scored the visibility level on a scale of 1 - 4. Results  The mean (± SD) visibility scores were 2.54 ± 1.10 for WLI, 3.02 ± 1.07 for BLI-bright, and 3.28 ± 0.97 for LCI. The score was significantly higher for BLI-bright compared with WLI ( P  < .001) and again higher for LCI compared with BLI-bright ( P  < .001). For the experts, the scores for BLI-bright and LCI were similar, but both were significantly higher than the score for WLI. For the trainees, there was no significant difference between the WLI and BLI-bright scores, but LCI score was significantly higher than those for WLI and BLI-bright scores. With regard to clinical characteristics, LCI particularly enhanced visibility of normochromic, flat and depressed lesions, which had the lowest visibility scores of all three modalities compared with those of the other lesions. Conclusion  LCI increased visibility and may contribute to early detection of gastric mucosal cancers.

Usefulness of close observation with non-magnified blue laser imaging for determining cold polypectomy indications

PURPOSE

To examine the usefulness of non-magnified close observation with blue laser imaging (BLI) using a colonoscope with close observation capability in determining indications for cold polypectomy.

METHODS

We conducted an image evaluation study on 100 consecutive colorectal lesions of 10 mm or less which were observed endoscopically without magnification using BLI mode prior to treatment. Two experts and two non-experts reviewed the images using the Japan NBI expert team (JNET) classification and the diagnostic accuracy was analyzed.

RESULTS

The final pathological diagnoses of the 100 lesions were hyperplastic/sessile serrated polyp (HP/SSP), low grade dysplasia (LGD), high grade dysplasia (HGD) and deep submucosal invasive cancer (dSM), respectively, in 12, 79, 9 and 0 lesions. When JNET classification type 1 corresponds to HP/SSP; 2A to LGD; 2B to HGD; and 3 to dSM; the overall diagnostic accuracy was 84.3%. Accuracy was 90.5% for experts and 78.0% for non-experts. High confidence rate was 67.5% for experts and 48.0% for non-experts. In diagnostic accuracy for HGD, the sensitivity, specificity, PPV and NPV were, respectively, 77.8%, 98.9%, 87.5% and 97.8% for experts; and 66.6%, 92.3%, 46.2% and 96.6% for non-experts.

CONCLUSIONS

The diagnostic accuracy of unmagnified close observation with BLI using a colonoscope with close observation capability is similar to that reported for magnifying endoscopy and is useful in predicting the histological diagnosis of colorectal polyps of 10 mm or less although the effectiveness may be limited for non-experts. This modality is a potentially useful tool in deciding indications for cold polypectomy.

Feasibility of endoscopic submucosal dissection for cecal lesions

BACKGROUND

The treatment results of endoscopic submucosal dissection (ESD) for colorectal lesions have improved markedly, but some lesions remain difficult to treat. Hence the cecum is considered a technically challenging site for ESD. We examined the feasibility of ESD for cecal lesions.

METHODS

Among a total of 708 colorectal ESD performed in our hospital between March 2006 and December 2016, 549 procedures performed after April 2012 were studied, at a time when the techniques of ESD had stabilized and the procedure was covered by health insurance in Japan. Among 549 cases, 61 were cecal lesions and 488 were noncecal lesions. The treatment outcomes were analyzed.

RESULTS

For cecal lesions, the en bloc resection rate was 95.1%, R0 resection rate was 91.8%, perforation rate was 0%, delayed bleeding rate was 6.6%, median diameter of resected specimen was 32 mm (16-65 mm), median time of the procedure was 44 minutes (8-140 min). The corresponding results for noncecal lesions were 97.3%, 95.5%, 0.4%, 2.7%, 30 mm (10-109 mm), and 37 min (7-225 min). No significant differences were observed and the good treatment results were seen. When the outcomes were analyzed for cecal sites considered to be particularly challenging; proximity to appendiceal orifice, the ileocecal valve, and the bottom of cecum, the treatment results were not inferior to other sites.

CONCLUSIONS

ESD is safe and effective even for cecal lesions considered challenging to treat. ESD is feasible for cecal lesions.

Magnified endoscopic observation of small depressed gastric lesions using linked color imaging with indigo carmine dye

BACKGROUND AND STUDY AIMS

Magnifying linked color imaging with indigo carmine dye (M-Chromo-LCI) enables sterically enhanced and color image-magnified observation of the superficial gastric mucosa. This study investigated the usefulness of M-Chromo-LCI for the differential diagnosis of gastric lesions.

PATIENTS AND METHODS

100 consecutive small depressed lesions were examined with conventional white-light imaging (C-WLI), magnifying blue-laser imaging (M-BLI), and M-Chromo-LCI. Endoscopic images were reviewed by three experts and three non-experts. Diagnostic accuracy and interobserver agreement were compared among the modalities.

RESULTS

For experts, M-BLI showed a significantly higher diagnostic accuracy than C-WLI (82.7 % vs. 67.0 %; P < 0.001). The diagnostic accuracy of M-Chromo-LCI was not different from M-BLI (87.7 % vs. 82.7 %; P = 0.31). For non-experts, M-BLI showed a significantly higher diagnostic accuracy than C-WLI (69.3 % vs. 52.3 %; P < 0.001). M-Chromo-LCI additionally showed a significantly higher diagnostic accuracy than M-BLI (79.7 % vs. 69.3 %; P = 0.005). M-Chromo-LCI had the highest interobserver agreement for each group.

CONCLUSIONS

M-Chromo-LCI is expected to become a useful modality for the accurate diagnosis of gastric lesions.

Linked-color imaging improves endoscopic visibility of colorectal nongranular flat lesions

BACKGROUND AND AIMS

As a newly developed image-enhanced endoscopy (IEE) technique, linked-color imaging (LCI) provides very bright images with enhanced color tones. With the objective of improving the detection rate of colorectal flat tumor lesions, which are difficult to detect, we examined the usefulness of LCI from the viewpoint of visibility.

METHODS

Fifty-three consecutive nongranular flat tumors were used in this study. Endoscopic images were acquired by white-light imaging (WLI), blue-laser imaging (BLI)-bright, and LCI modes. For each lesion, we selected 1 image each acquired by WLI, BLI-bright, and LCI modes. Six endoscopists interpreted the images. By using a previously reported visibility scale, we scored the visibility level on a scale of 1 to 4.

RESULTS

The mean (± standard deviation) visibility scores were 2.74 ± 1.08 for WLI, 2.94 ± 0.97 for BLI-bright, and 3.36 ± 0.72 for LCI. The score was significantly higher for BLI-bright compared with WLI (P < .001) and again higher for LCI compared with BLI-bright (P < .001). When we compared between experts and trainees, the corresponding scores of experts were 2.83 ± 1.06, 3.17 ± 0.88, and 3.40 ± 0.74, with a tendency similar to the scores of all endoscopists. For the trainees, there was no difference between the scores for WLI (2.65 ± 1.10) and BLI-bright (2.71 ± 1.00), but the score for LCI (3.31 ± 0.69) was significantly higher than that for WLI or BLI-bright (P < .001). When only sessile serrated adenoma/polyp lesions were analyzed, LCI remained significantly higher than the other 2.

CONCLUSIONS

The present findings suggest that LCI increases the visibility of colorectal flat lesions and contributes to improvement of the detection rate for these lesions.