Colorectal endoscopic submucosal dissection using a concealable robotic add-on device: A comparative in vivo feasibility study.

318 Background: Effective traction and counter-traction for visualizing the dissection plane in endoscopic submucosal dissection (ESD) is difficult to be achieved with a conventional endoscope. We developed a robotic assistive traction device for flexible endoscopy that provides multi-directional traction during ESD. We compared its safety and efficiency in ESD between experienced and novice endoscopists. Methods: Robotic ESD was performed by experienced and novice endoscopist groups (n = 2, each). The outcomes included time to complete each ESD step, total procedure time, size of the dissected mucosa, rate of en bloc resection, and major adverse events. Furthermore, incision and dissection speeds were compared between groups. Results: Twenty gastric lesions were resected from nine live pigs. The submucosal incision speed was significantly faster in the expert group than in the novice group (P = 0.002). There was no significant difference in the submucosal dissection speed between the groups (P = 0.365). No complications were reported in either group. Conclusions: When the robot was assisting in the ESD procedure, the dissection speed improved significantly, especially in the novice surgeons. Our robotic device can provide simple, effective, and safe multidirectional traction during ESD.

P-247 In vivo feasibility study of a robotic arm-assisted endoscopic submucosal dissection for early gastric cancer

Using conventional endoscope to perform endoscopic submucosal dissection (ESD) is difficult because of the one-handed operation and blind dissection caused by gravity. Poor visualization of the submucosal plane causes ESD to be associated with a high risk of bleeding and perforation. This study aimed to develop a novel ESD-assistive robot system and to evaluate its efficacy. A novel flexible auxiliary single-arm transluminal endoscopic robot (FASTER) was developed. A total of 36 artificial lesions in ex vivo porcine stomachs were removed using the FASTER-assisted ESD method (n = 18) and the conventional ESD method (n = 18). Lesions were 2cm or 4cm in diameter, located on the anterior and posterior walls of the antrum. Primary outcome measurements were dissection time and dissection speed. The dissection time in FASTER-assisted ESD was significantly shorter than that in conventional ESD (7min vs 13min, p = 0.012), mainly because of the faster dissection speed (148.6 vs 97.0 mm2/min, p = 0.002). The total procedure time in FASTER-assisted ESD was shorter than that in conventional ESD, but the difference was not significant (16min vs 24min, p = 0.252). Complete en bloc resection was achieved in all lesions. No perforations were detected. The FASTER exhibited the ability of regrasp, multidirectional traction, and proper tension control during ESD. FASTER significantly increased the dissection speed by providing proper traction and achieving good submucosal vision. This new device is expected to facilitate ESD in clinical practice.

Background:Colorectal endoscopic submucosal dissection is a technically demanding but effective treatment for superficial neoplasms. We conducted a study to compare the effectiveness and safety of inner traction-facilitated endoscopic submucosal dissection using rubber band and clip with conventional endoscopic submucosal dissection.Methods:We retrospectively evaluated 622 consecutive patients who underwent colorectal endoscopic submucosal dissection between January 2016 and December 2019. To overcome selection bias, we used propensity score matching (1:4) between endoscopic submucosal dissection using rubber band and clip and conventional endoscopic submucosal dissection. The frequency of en bloc resections, R0 resections, curative resections, procedure speed, and complications were evaluated.Results:After propensity score matching, 35 patients were included in the endoscopic submucosal dissection using rubber band and clip group and 140 were included in the conventional endoscopic submucosal dissection group. Endoscopic submucosal dissection using rubber band and clip resulted in a significant increase in resection speed (0.14 vs. 0.09 cm2/min; P = .003). There were no significant differences in en bloc, R0, and curative resection rates between the 2 groups. In subgroup analysis, the resection speed of endoscopic submucosal dissection using rubber band and clip was significantly higher than that of conventional endoscopic submucosal dissection when the lesions were equal to or larger than 2 cm, macroscopically presenting as lateral spreading tumor, and located in transverse colon to ascending colon.Conclusions:Endoscopic submucosal dissection using rubber band and clip is safe and effective in treating colorectal neoplasms, especially in lesions presenting a particular difficulty.

Are We Ready to Embrace Endoscopic Submucosal Dissection as the Organ-Sparing, Minimally Invasive Endoscopic Surgical Procedure of Choice for Large Colorectal Adenomas and Early Cancers?

The goal of this study was to compare the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) with endoscopic submucosal dissection (ESD) for the removal of early-stage esophageal squamous cancer wider than or equal to one half the circumference of the esophagus. Although ESD has been successfully applied for resection of early-stage esophageal cancer, there are still technical challenges and postoperative stenosis when it is applied to treat large lesions. A total of 40 patients with early-stage esophageal cancer wider than or equal to one half its circumference were enrolled in this study and randomly assigned to an ESTD or ESD group for treatment of esophageal superficial squamous cell carcinoma. All of the patients received oral steroids after endoscopic dissection. We then compared the 2 groups in terms of average operating time, dissection speed, en bloc resection rate, R0 resection rate, and complications during a 1-year follow-up period. The dissection speed in the ESTD group was significantly faster than that in the ESD group (P=0.047). There were no significant differences in operating time, en bloc resection rates, or R0 resection rates between the ESTD and ESD group (P=0.319, 1.000, 1.000, respectively). There were also no significant differences in perforation, bleeding, or stenosis rates between the ESTD and ESD group (P=1.000, 0.748, 1.000, respectively). Both ESTD and ESD are safe and effective therapies for early-stage esophageal cancer wider than or equal to one half the esophageal circumference. The dissection speed of ESTD is faster than that of ESD.

Hybrid endoscopic submucosal dissection (ESD) is increasingly utilized to overcome the complexity of conventional ESD. This systematic review and meta-analysis evaluated the efficacy and safety of hybrid ESD for treatment of colorectal lesions. Search strategies were developed in accordance with PRISMA guidelines. Pooled proportions were calculated with rates estimated using random effects models. Measured outcomes included en bloc resection, procedure-associated complications, recurrence, and need for surgery. Subgroup analyses were performed to compare effectiveness of conventional versus hybrid ESD. 16 studies (751 patients) were included with a mean (standard deviation [SD]) lesion size of 27.96 (10.55) mm. En bloc resection rate was 81.63 % (95 % confidence interval [CI] 72.07 - 88.44; I2 = 80.89). Complications, recurrences, and need for surgery occurred in 7.74 % (95 %CI 4.78 - 12.31; I2 = 65.84), 4.52 % (95 %CI 1.40 - 13.65; I2 = 76.81), and 3.64 % (95 %CI 1.76 - 7.37; I2 = 15.52), respectively. Mean procedure duration was 48.83 (22.37) minutes. On subgroup analyses comparing outcomes for conventional (n = 1703) versus hybrid ESD (n = 497), procedure duration was significantly shorter for hybrid ESD (mean difference 18.45 minutes; P = 0.003), with lower complication rates (P = 0.04); however, hybrid ESD had lower en bloc resection rates (P < 0.001). There was no difference in rates of recurrence or surgery (P > 0.05). While hybrid ESD was safe and effective for removal of colorectal lesions, with shorter procedure duration, fewer complications, and no difference in recurrence versus conventional ESD, hybrid ESD was associated with a lower en bloc resection rate.

Mo1670 EFFICACY AND SAFETY OF ESTD AND ESD IN THE TREATMENT OF LARGE AREA RECTAL LATERALLY SPREADING TUMORS

INTRODUCTION:Colorectal endoscopic submucosal dissection (ESD) is a technically demanding operation with a long learning curve. The aim of this study was to determine whether orthodontic rubber band (ORB)-assisted colorectal ESD could improve the trainees' learning curve as it was shown to shorten colorectal ESD procedure time in trainees and experts.METHODS:This prospective, randomized, controlled clinical study involved 178 patients who underwent colorectal ESD, randomly divided into trainee ORB-assisted ESD (Trainee ORB-ESD; n = 60), trainee conventional ESD (Trainee C-ESD; n = 57), and expert conventional ESD (Expert C-ESD; n = 61) groups. The main outcome was procedure time.RESULTS:Per Protocol analysis showed a similar operative time in the trainee ORB-ESD and expert C-ESD groups, which was shorter than in the trainee C-ESD group [28.0 (21.0–35.0) and 25.0 (15.0–35.0) vs 41.0 (31.0–52.5) min; (P < 0.001)]. The trainee ORB-ESD, trainee C-ESD, and expert C-ESD groups differed significantly in resection speed (11.35, 9.07, and 12.56 mm2/min, respectively), good visual field exposure rate (96.7%, 80.7%, and 93.4%), and muscle injury rate (5.0%, 17.5%, and 6.6%). However, the trainee ORB-ESD and expert C-ESD groups were similar in these measures, and all 3 groups were similar in adverse events, en bloc resection, R0 resection, and pathology rates. The cumulative sum suggested that the learning inflection point of the trainee ORB-ESD group was earlier than that of the trainee C-ESD group.DISCUSSION:ORB-ESD shortened colorectal ESD procedure time and improved efficiency in trainees to an expert level. ORB-ESD could shorten the learning curve, justifying its widespread application.

Objectives: With endoscopic submucosal dissection and laparoscopic surgery, treatment for colorectal neoplasms has become minimally invasive. However, few studies have compared endoscopic submucosal dissection with laparoscopic surgery for colorectal neoplasms, excluding deeply invasive cancer on preoperative diagnosis. Methods: We retrospectively reviewed the files of patients who had undergone endoscopic submucosal dissection or laparoscopic surgery for colorectal neoplasms between November 2005 and December 2015. We limited patients who were not suspected preoperatively to have aggressive submucosal invasion >1,000 μm. Results: Ninety-five patients underwent endoscopic submucosal dissection and 37 underwent laparoscopic surgery. Cases of endoscopic submucosal dissection tended to involve rectal neoplasms more often than colonic neoplasms, shorter operative times, and shorter lengths of hospital stay compared with laparoscopic surgery. The perforation rate during colonic endoscopic submucosal dissection in the early period (November 2005 to December 2010) and late period (January 2011 to December 2015) was 14.8% and 2.9%, respectively. In all cases of perforation during colonic endoscopic submucosal dissection, the ability to maneuver the endoscope was compromised. Though tumors were larger in patients who underwent rectal endoscopic submucosal dissection compared with colonic endoscopic submucosal dissection, the perforation and postoperative bleeding rates with rectal endoscopic submucosal dissection were both 3.2%. The most common indication for laparoscopic surgery was difficulty performing endoscopic submucosal dissection. Serious complications were rare. Conclusions: For colonic neoplasms, laparoscopic surgery should be considered when endoscopic submucosal dissection is technically difficult in the early period. For rectal neoplasms, endoscopic submucosal dissection is desirable even for those of large size.

Endoscopic submucosal dissection (ESD) in the upper and middle thirds of the stomach is technically challenging. There are few reports on the use of pulley traction (PT), which involves using orthodontic rubber bands and dental floss to assist with ESD, in this area. We aimed to explore the efficacy of PT-ESD in this region and compare it with conventional ESD (C-ESD). One hundred ninety-seven patients who underwent ESD for lesions located in the upper and middle parts of the stomach was conducted. There were 40 cases in the PT-ESD group and 157 in the C-ESD group. The primary outcome measure was dissection speed. Prior to propensity score matching (PSM), the lesion size and specimen diameter were larger in the PT-ESD group than in the C-ESD group. The PT-ESD group also experienced a longer procedure time (78.5 ± 28.7 vs. 64.9 ± 44.0min, P = 0.02). However, the PT-ESD group had a significantly faster dissection speed (20.8 [IQR, 16.4, 30.6] vs. 9.4 [IQR, 6.0, 13.1] mm2/min, P < 0.001). There were no statistically significant differences in en bloc resection, R0 resection rate, adverse events or pathological results. PSM matched 30 pairs of patients. Although the long diameter of the specimens in the PT-ESD group was larger, the procedure time for both groups was comparable, and the dissection speed of the PT-ESD group remained faster (P < 0.001). The studied pulley traction method demonstrated a good dissection speed and an acceptable complication rate for lesions in the upper and middle thirds of the stomach. It is a feasible and safe traction method.

Multiple large colorectal lesions requiring endoscopic submucosal dissection (ESD) are sometimes diagnosed during colonoscopy. We evaluated the feasibility and safety of ESD of two colorectal lesions in one session. The lesions of 16 patients who underwent two ESD procedures in a single session (double ESD group) from November 2009 to July 2014 were matched with those of 64 patients who underwent a single ESD procedure (single ESD group) based on the size and location of the lesion and presence of submucosal fibrosis. The net ESD time per patient was longer in double ESD group than in single ESD group (104.0±36.2 vs. 59.1±39.2 min, p<0.001). The net ESD time per lesion tended to be shorter in double ESD group than in single ESD group (49.6±30.0 vs. 59.1±39.2 min, p=0.077). The en bloc resection and curative resection rates did not differ between double ESD and single ESD groups (93.8 % vs. 98.4%, p=0.262; 90.6 % vs. 84.4 %, p=0.534, respectively). The intra- and postprocedural bleeding rates were 12.5% and 0% in double ESD group and 15.6% and 3.1% in single ESD group, respectively. Perforation occurred in two (6.3%) in double ESD group and in six (9.4%) in single ESD group (p=0.715). Compared with the single ESD, two simultaneous colorectal ESD procedures in a patient did not increase complications; the en bloc and curative resection rates were similar when performed a single ESD procedure and two simultaneous ESD procedures.

Endoscopic submucosal dissection (ESD) was developed for the removal of benign and early malignant lesions in the gastrointestinal tract. We aimed to evaluate the performance and safety of a novel high-pressure waterjet-assisted ESD knife in colorectal applications. Six female German Landrace pigs with an average weight of 62 kg (range 60-65 kg) were used in this prospective, randomized, and controlled study. Twenty-four ESDs were performed by three endoscopists: Twelve each with the new Erbe HYBRIDknife® flex T-Type (HK-T) and the Olympus DualKnife® J (DK-J), including six rectal and six colonic ESDs per instrument. The order of performance was randomized regarding anatomic position and instrument. As the primary endpoint, ESD knife performance characteristics were combined and rated on a 5-point Likert scale, with 5 Likert points (LP) representing the best response (5 = very good). The HK-T was rated significantly better than the DK-J (4.7 LP versus 4.4 LP, p = 0.0295), mainly because of HK-T injection ability (5 LP versus 3 LP, p < 0.0001) and hemostasis (5 LP versus 4 LP, p = 0.0452). There was no difference in procedure time (HK-T: 35 min versus DK-J: 34 min, p = 0.8005), resection diameter (3.1 cm versus 2.8 cm, p = 0.3492), injection volume (41 mL versus 46 mL, p = 0.5633), and complication rates. HK-T is as effective as DK-J in colorectal ESD in terms of dissection quality but has better injection and hemostatic properties. The impact of these technical advantages on the ESD treatment of patients with large superficial colorectal lesions remains to be clinically verified.

Background colorectal endoscopic submucosal dissection (ESD) remains a technical challenge, but traction devices show promise in making this procedure easier. However, the efficacy of traction techniques for colorectal ESD is still unknown for inexperienced endoscopists. Methods We selected 400 patients who underwent colorectal ESD performed by four inexperienced endoscopists. Each patient in the traction-assisted ESD (TA-ESD) group was matched to a patient in the conventional ESD (C-ESD) group according to propensity scores. Results One-to-one propensity score-matching analysis created 87 matched pairs. The self-completion rate in the TA-ESD group is significantly higher than that in the C-ESD group (100% [87/87] vs. 92% [80/87], p < 0.001). The median resection speed was significantly faster in the TA-ESD group than that in the C-ESD group (27 mm2/min [IQR, 19.5–47.3] vs.18 mm2/min [IQR, 13.5–33.8], p < 0.001) and the procedure time in the TA-ESD group was significantly shorter than that in the C-ESD group (33 min [IQR, 27–47] vs.53 min [IQR, 38–73], p < 0.001). However, the histologic complete resection rate was not significantly different between the TA-ESD and C-ESD groups (93.1% [6/87]) vs. 96.6% [3/87], p < 0.1888, respectively). The en bloc resection rate (96.6%) and perforation rate (4.6%) were equivalent between the TA-ESD group and the C-ESD group. Conclusion Traction techniques seem to improve resection speed and self-completion rate of colorectal ESD for inexperienced endoscopists.

Background and study aim The role of colorectal endoscopic submucosal dissection (ESD) is standardized in Japan and East Asia, but technical difficulties hinder its diffusion. The aim was to identify predictors of difficulty for each neoplasm type.Methods A competent operator performed all procedures. ESD difficulty was defined as: en bloc with a slow speed (< 0.07 cm2/min; 30 × 30 mm neoplasm in > 90 min), conversion to endoscopic mucosal resection, or resection abandonment. Pre- and intraoperative difficulty variables were defined according to standard criteria, and evaluated separately for the rectum and colon. Difficulty predictors and gradients were evaluated by the multivariate logistic regression model.Results A total of 140 ESDs were included: 110 in the colon and 30 in the rectum. Neoplasms were laterally spreading tumors – granular type (LST-G) in 85 cases (61 %); the median longer axis was 30 mm (range 15 – 180 mm); a scar was present in 15 cases (11 %). ESD en bloc resection and difficulty rates were 85 % (n = 94) and 35 % (n = 39) in the colon, and 73 % (n = 22) and 50 % (n = 15) in the rectum (P = 0.17 and 0.28, respectively). The scar was the only preoperative predictor of difficulty in the rectum (odds ratio [OR] 12.3, 95 % confidence interval [CI] 1.27 – 118.36), whereas predictors in the colon were: scar (OR 12.7, 95 %CI 1.15 – 139.24), LST – nongranular type (NG) (OR 10.5, 95 %CI 1.20 – 55.14), and sessile polyp morphology (OR 3.1, 95 %CI 1.18 – 10.39). Size > 7 – ≤ 12 cm2(OR 0.20, 95 %CI 0.06 – 0.74) and operator experience > 120 procedures (OR 0.19, 95 %CI 0.04 – 0.81) were predictors for a easy procedure. No intraoperative predictors of difficulty were identified in the rectum, whereas predictors in the colon were: severe submucosal fibrosis (OR 21.9, 95 %CI 2.11 – 225.64), ineffective submucosal exposure by gravity countertraction (OR 12.3, 95 %CI 2.43 – 62.08), and perpendicular submucosal dissection approach (OR 5.2, 95 %CI 1.07 – 25.03). When experience was /= 90, preoperative gradient of colonic ESD difficulty was the highest for LST-NGs (scar positive and negative up to 47 % and 20 %, respectively), intermediate for sessile polyps with scar (up to 23 %), and the lowest for LST-Gs (< 8 %). Different difficulty gradients between neoplasm types persisted with increasing experience: LST-NG rate up to 14 % after 120 procedures.Conclusions Colonic and rectal ESD difficulty has qualitative differences. Preoperative predictors should be considered to identify the difficulty gradient of each neoplasm type and the appropriate setting for ESD.