Risk of lens cloudiness during colorectal endoscopic submucosal dissection and ability of a novel lens cleaner to maintain and restore endoscopic view

Prospective randomized trial comparing conventional and underwater endoscopic submucosal dissection for superficial colorectal neoplasms

This study compared procedure-related outcomes of conventional and underwater endoscopic submucosal dissection (ESD) for superficial colorectal neoplasms (SCNs).In this single-center, randomized controlled trial, patients with SCNs meeting the indications of the Japanese guidelines for ESD were randomly assigned to undergo conventional ESD (CESD) or underwater ESD (UESD) performed by an expert. The primary endpoint was dissection speed, defined as the specimen area per ESD time.We analyzed the data of 69 and 70 CESD and UESD cases, respectively; however, no significant differences were found in median dissection speed (17.4 and 19.9 mm2/min, respectively; P=0.19). Multiple regression analysis revealed that the suitable positional relationship between the lesion and the direction of gravity (nongravity side for CESD and gravity side for UESD) was independently and positively associated with dissection speed (P<0.001). En bloc resection was achieved without perforation in all cases. The incidence of post-ESD coagulation syndrome was not significantly different between the two groups (4.3% vs. 2.9%, respectively; P=0.68).UESD did not expedite dissection speed in the overall patient population. CESD and UESD may be complementary in the colorectum depending on the positional relationship between the lesion and the direction of gravity.

Development of anti-fouling endoscope tip hood for gastrointestinal endoscopy

The contamination of the endoscope tip lens results in poor endoscopic imaging. To prevent the adsorption of contaminants, we applied a soft contact lens made of 2-hydroxyethyl methacrylate hydrogel to the tip of a gastrointestinal endoscope. Additionally, a novel endoscopic hood with an upper surface composed of a single layer inside the hood cavity was developed. For in vitro anti-fouling performance testing using blood, changes in light transmittance were examined with hydrogel plates and compared to conventional quartz glass and surfactant-coated glass. The transmittance changes at a wavelength of 415 nm were 1.5% for the hydrogel plate, significantly lower than 82.9% for quartz glass and 85.2% for surfactant-coated glass (p < 0.001), demonstrating the hydrogel's high anti-fouling performance. Another in vitro quantitative assay, evaluated by exposure to blood, lipid, and mucin liquids, showed high anti-fouling performance in the order hydrogel plate > surfactant-coated glass > quartz glass. Moreover, an in vivo pig model performing gastric endoscopic submucosal dissection was used to evaluate anti-fouling performance by analyzing endoscopic images with Michelson contrast. The contrast value of the upper surface group (Hydrogel) was 0.97, significantly higher than 0.62 for the non-upper surface group (Surfactant) (P < 0.001). Therefore, the novel anti-fouling endoscope tip hood could be applied in future clinical applications.

Analysis of lens cloudiness during endoscopic submucosal dissection procedures: Effects of a novel lens cleaner

Objectives

We aimed to identify independent factors for intraoperative endoscopic lens cloudiness during gastric and colorectal endoscopic submucosal dissections, investigate the effectiveness of Cleastay, an endoscope anti-fog solution, and examine factors associated with severe submucosal fat deposition.

Methods

A total of 220 patients who underwent gastric or colorectal endoscopic submucosal dissections in two institutions between January 2022 and October 2023 were included. Significant factors related to cloudiness were determined using univariate and multivariate analyses. Patient background and tumor characteristics related to severe submucosal fat deposition were investigated, and the degree of intraoperative endoscopic lens cloudiness and outcomes were compared between the Cleash and Cleastay groups.

Results

In the multivariate analysis, factors increasing lens cloudiness included long procedure time (odds ratio [OR], 17.51; 95% confidence interval [CI], 1.52-202.08), stomach (vs. colon; OR, 5.08; 95% CI, 1.99-12.96), and severe submucosal fat deposition (OR, 12.19; 95% CI, 5.02-29.60). Conversely, the use of Cleastay (vs. Cleash; OR, 0.066; 95% CI, 0.021-0.21) was identified as a factor reducing cloudiness. Location analysis revealed that severe submucosal fat deposition was more common in the upper stomach and right colon.

Conclusions

It was suggested that Cleastay is more useful for endoscopic submucosal dissection of the upper stomach and right colon, where severe submucosal fat deposition is expected.

Comparing underwater endoscopic submucosal dissection and conventional endoscopic submucosal dissection for large laterally spreading tumor: a randomized controlled trial (with video)

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is challenging despite its usefulness. Underwater ESD (UESD) provides better traction and a clearer view of the submucosal layer than conventional ESD (CESD). This study compared the efficiency of UESD and CESD for large (20-50 mm) laterally spreading tumors (LSTs).

METHODS

Preplanned sample size was calculated from our previous experience. As a result, 28 patients were required for the UESD group and CESD group each. The primary outcome was total procedure time; the secondary outcome was dissection speed.

RESULTS

Fifty-six patients were enrolled, and a total of 28 patients were assigned to each group. The mean LST size was 31.6 mm and 31.3 mm in the UESD and CESD groups, respectively. Fibrosis was observed in 67.9% and 60.7% of patients in the UESD and CESD groups. Total procedure time (mean ± standard deviation) for the UESD group was significantly shorter than that for the CESD group (49.5 ± 20.3 minutes vs 75.7 ± 36.1 minutes; mean difference, -26.2 minutes; 95% confidence interval, -42.0 to -10.5 minutes). Dissection speed of the UESD group was significantly faster than that of the CESD group (21.9 ± 6.9 mm2/min vs 15.2 ± 7.3 mm2/min; mean difference, 6.7 mm2/min; 95% confidence interval, 2.8 to 10.4 mm2/min). There was no difference between groups in the R0 resection rate or en bloc resection rate. No perforations were observed in either group.

CONCLUSIONS

UESD was superior to CESD in total procedure time and dissection speed. UESD can be recommended as the preferred method for the resection of large LSTs.

Is there a best choice of equipment for colorectal endoscopic submucosal dissection?

INTRODUCTION

Endoscopic submucosal dissection (ESD) is a widely used technique to remove early neoplastic lesions. It was primarily used in the initial days to treat gastric lesions, but recently, the horizon of this endoscopic procedure has expanded, which has allowed us to manage other technically more complex locations, such as the colorectum.

AREAS COVERED

There has been an exponential growth regarding the wide range of devices available in the market for performing colorectal ESD. As a result, the aim of this review is to highlight the indication of this endoscopic technique, which device is best suited for which indication, as well as future trajectories in this field.

EXPERT OPINION

Although some devices have proven to be more advantageous than others in this area, very often the choice is still subjective, which is commonly attributed to individual preferences and experience. However, an accurate knowledge of the available tools and their functioning, with their pros and cons, is fundamental for any endoscopist venturing into the field of third space endoscopy. In this way, one can choose which device best suits a particular situation, along with simultaneously having the wealth of knowledge related to therapeutic armamentarium at our disposal in the endoscopy suite.

The usefulness of combining the pocket-creation method with a traction device using a scissor-type knife for colorectal endoscopic submucosal dissection

INTRODUCTION

Technical issues and long procedure time still remain a concern in colorectal endoscopic submucosal dissection (ESD). We examined the usefulness of combining the pocket-creation method (PCM) with a traction device (S-O clip; SO) using a scissor-type knife (Clutch Cutter 3.5 mm; CC) for decreasing ESD procedure time.

METHODS

We retrospectively analyzed 95 ESD cases of PCM + SO + CC managed from August 2017 to April 2020 and 103 cases of PCM + CC treated from July 2016 to July 2017. We compared these two groups through propensity score matching. The main outcome was the analysis of the ESD procedure times under various conditions in each group.

RESULTS

After matching, 52 cases in the PCM + SO + CC and PCM + CC groups were analyzed. The PCM + SO + CC group showed a significantly shorter ESD procedure time than the PCM + CC group (57.8 ± 31.4 vs. 81.7 ± 33.5 min, p < 0.01). Additionally, the ESD procedure time was significantly shorter in the PCM + SO + CC group than in the PCM + CC group: tumor size (tumor size < 40 mm: 45.6 ± 15.8 vs. 72.7 ± 22.9 min, p < 0.01; tumor size ≥ 40 mm: 83.1 ± 40.1 vs. 111.8 ± 45.3 min, p = 0.04), tumor location (right side: 64.7 ± 33.3 vs. 81.0 ± 29.7 min, p = 0.03; left side: 50.5 ± 28.0 vs. 82.3 ± 36.9 min, p < 0.01), tumor morphology (polypoid: 39.2 ± 18.6 vs. 74.7 ± 28.6 min, p < 0.01; nonpolypoid: 62.3 ± 32.3 vs. 84.5 ± 35.2 min, p < 0.01), endoscopist (expert: 67.3 ± 41.2 vs. 91.9 ± 40.2 min, p = 0.02; nonexpert: 50.4 ± 18.3 vs. 73.6 ± 24.9 min, p < 0.01), and fibrosis (severe fibrosis: 82.0 ± 20.5 vs. 99.8 ± 40.4 min, p = 0.169; non-severe fibrosis: 52.1 ± 23.8 vs. 75.6 ± 29.0 min, p < 0.01).

CONCLUSIONS

The combination of the PCM and SO using CC achieved a reduction in the colorectal ESD procedure time.

The impact of submucosal fatty tissue during colon endoscopic submucosal dissection in a western center

OBJECTIVES

Obesity is associated with submucosal fatty tissue. The main aim of this study was to assess the impact of submucosal fatty tissue on the success of colonic endoscopic submucosal dissection (C-ESD) in a western population.

METHODS

This was a retrospective analysis of 125 consecutive C-ESDs performed between October 2015 and July 2017. Fatty tissue sign was defined as positive when the submucosal layer was covered with fatty tissue. The complexity of performing an ESD was assessed by the performing endoscopist, defined by the occurrence of intraprocedural perforation, inability to complete an en-bloc resection or a procedure time exceeding 180 min.

RESULTS

Fatty tissue sign positive was present in 44.8% of the procedures. There were 28 (22.4%) c-ESD defined as complex. Factors associated with complex ESD included; fatty tissue sign [odds ratio (OR) 12.5; 95% confidence interval (CI), 1.9-81.9; P = 0.008], severe fibrosis (OR 148.6; 95% CI, 6.6-3358.0; P = 0.002), poor maneuverability (OR 267.4; 95% CI, 11.5-6212.5; P < 0.001) and polyp size ≥35 mm (OR 17.2; 95% CI, 2.6-113.8; P = 0.003). In patients demonstrating the fatty tissue sign, BMI and waist-to-height ratio (WHtR) were higher (27.8 vs. 24.7; P < 0.001 and 0.56 vs. 0.49; P < 0.001, respectively) and en-bloc resection was achieved less frequently (76.8 vs. 97.1%, P = 0.001). Multivariate analysis revealed higher risk of fatty tissue sign positive associated with WHtR ≥0.52 (OR 26.10, 95% CI, 7.63-89.35, P < 0.001).

CONCLUSION

This study demonstrates that the fatty tissue sign contributes to procedural complexity during C-ESD. Central obesity correlates with the likelihood of submucosal fatty tissue and as such should be taken into account when planning procedures.

Impact of obesity in colorectal endoscopic submucosal dissection: single-center retrospective cohort study

BACKGROUND

When performing colorectal endoscopic submucosal dissection (ESD) in obese patients, technically difficult cases are sometimes experienced because of difficulty with the insertion of the colonoscope, poor scope maneuverability, or an abundance of fat tissue in the submucosal layer. Since the association between obesity and colorectal ESD has not been investigated, we evaluated the clinical impact of obesity in patients who underwent colorectal ESD.

METHODS

We retrospectively reviewed 535 patients who underwent colorectal ESD between April 2012 and February 2019. Patients were divided into three groups based on their body mass index (BMI): a control group (BMI < 25 kg/m2), an overweight group (25 kg/m2 ≤ BMI < 30 kg/m2), and an obese group (BMI ≥ 30 kg/m2), and the short-term clinical outcomes were analyzed to assess the safety and difficulty of colorectal ESD.

RESULTS

No significant difference in the procedure times, en bloc resection rates, pathological diagnoses, or complications were seen among the groups. While the amount of sedative per body weight was significantly lower in the group with a higher BMI (flunitrazepam: 1.75 × 10-2 [1.27 × 10-2-2.34 × 10-2] mg/kg vs. 1.48 × 10-2 [1.08 × 10-2-2.03 × 10-2] mg/kg vs. 1.16 × 10-2 [0.98 × 10-2-1.54 × 10-2] mg/kg, P < 0.001; pethidine: 0.63 [0.55-0.72] mg/kg vs. 0.50 [0.46-0.56] mg/kg vs. 0.39 [0.32-0.45] mg/kg, P < 0.001), a reduction in percutaneous arterial oxygen saturation occurred significantly more frequently in the group with a higher BMI (123 [30.2%] vs. 43 [43.9%] vs. 10 [55.6%], P = 0.005). When the procedures were performed by trainees, the number of cases that required a procedure time of longer than 90 min was significantly larger in the group with a higher BMI (27 [10.8%] vs. 14 [21.9%] vs. 3 [25.0%], P = 0.033).

CONCLUSIONS

This study showed that colorectal ESD could be performed safely and effectively in obese patients. However, ESD in obese patients requires attention, particularly to changes in respiratory conditions.

Effectiveness of Solution with 5% Detergent for Cleaning Transnasal Esophagogastroduodenoscopy Lens

BACKGROUND/AIMS

Unsedated transnasal esophagogastroduodenoscopy (EGD) is affected by a poor scope lens-cleaning function. We have previously reported good, albeit limited, effects of an oolong tea washing solution; here, we evaluated the effectiveness of a 5% lens cleaning solution for cleaning an EGD lens.

METHODS

Five percent lens cleaning solution (C), 5% dimethicone solution (D), and distilled water (W) were prepared. Study I: Lenses were soiled with pork grease, washed with each washing solution, and their image quality was judged. Study II: Patients (n=996) scheduled for transnasal EGD were randomly assigned to the C- or W-group. Lens cleanliness level, washing solution volume used, and endoscopist stress due to lens contamination were determined.

RESULTS

Study I: The image quality of the lenses washed with (C) was significantly superior. (D) was clinically unsuitable because of spray nozzle clogging. Study II: Lens cleaning in the C-group was significantly superior (p<0.0001) and the solution volume required was significantly reduced (p<0.0001), while endoscopist stress was also lower (p<0.0001).

CONCLUSION

For transnasal small-caliber EGD, the present 5% lens cleaning solution provided good visibility. It features a high detergency level and is simple to formulate for therapeutic endoscopy applications, such as endoscopic submucosal dissection.

Saline-pocket endoscopic submucosal dissection for superficial colorectal neoplasms: a randomized controlled trial (with video)

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is a time-consuming procedure because of the technical difficulty. The newly developed saline-pocket ESD (SP-ESD) provides a clearer view and better traction of the submucosal layer compared with the standard ESD with gas insufflation (S-ESD). This study aimed to prospectively compare the efficacy and safety between S-ESD and SP-ESD in patients with superficial colorectal neoplasms (SCNs).

METHODS

From April 2017 to November 2018, 95 patients with SCNs ≥20 mm in diameter were prospectively and randomly enrolled. Four patients were excluded because of an incomplete ESD procedure. Patients were finally allocated to 2 groups, S-ESD with 45 patients and SP-ESD with 46 patients. The primary outcome was dissection speed. Secondary outcomes were ESD procedure time, en bloc and complete resection rates, perforation rate, and adverse effects.

RESULTS

Median dissection speed was significantly faster in the SP-ESD than the S-ESD group (20.1 mm²/min [range, 17.3-28.1] vs 16.3 mm²/min [range, 11.4-19.8]; P < .001). Median procedure time was significantly shorter in the SP-ESD than the S-ESD group (29.5 minutes [range, 22.3-44] vs 41 minutes [range, 31-55]; P < .001). The en bloc and complete resection rates were 100% in both groups. No perforations occurred among patients. The volume of saline solution used in the SP-ESD group was significantly greater than that in the S-ESD group (200 mL [range, 120-250] vs 150 mL [range, 100-200]; P = .016).

CONCLUSIONS

SP-ESD improved dissection speed and procedure time compared with S-ESD. SP-ESD may be an alternative method for resection of SCNs. (Clinical trial registration number: UMIN 000026317.).

Dual Red Imaging Maintains Clear Visibility During Colorectal Endoscopic Submucosal Dissection

BACKGROUND

The endoscopic lens becomes clouded and its visibility reduces during colorectal endoscopic submucosal dissection (ESD), especially in cases with submucosal fatty tissue. Dual red imaging (DRI) is a novel image-enhanced endoscopic technique that improves endoscopic visibility.

AIMS

This study aimed to evaluate the predictive factors of submucosal fatty tissue and the clinical usefulness of DRI in maintaining clear visibility during colorectal ESD.

METHODS

The study participants included 586 consecutive patients with 645 colorectal tumors who underwent ESD between January 2014 and July 2017. First, the degree of submucosal fatty tissue was evaluated by reviewing recorded images, and the clinical characteristics of the patients and tumors related to severe submucosal fatty tissue were evaluated. Second, 34 tumors resected using DRI were propensity score-matched in a 1:1 ratio to other resected tumors using white light imaging (WLI), and the degree of endoscope lens cloudiness and clinical outcomes were evaluated.

RESULTS

The proportion of tumors located in the right side of the colon, body mass index (≥ 25, BMI), and hemoglobin A1c (≥ 6.5%, HbA1c) were significantly higher in patients with severe submucosal fatty tissue. The visibility in the DRI group was significantly better than in the WLI group. Treatment outcomes in the DRI group were as good as those in the WLI group.

CONCLUSIONS

Tumor location in the right side of the colon, BMI (≥ 25), and HbA1c (≥ 6.5%) are the predictive factors of severe submucosal fatty tissue. DRI is useful in maintaining clear visibility during colorectal ESD, especially with submucosal fatty tissue.

The efficacy of the pocket-creation method for cases with severe fibrosis in colorectal endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

 Severe fibrosis poses a challenge in colorectal endoscopic submucosal dissection (ESD). Recently, the pocket-creation method (PCM) has been developed for overcoming various difficulties of ESD. A specific tapered hood is used for adequate traction in the PCM, and endoscopic operability becomes stable in the pocket. In this study, we investigated the efficacy of the PCM in ESD for cases with severe fibrosis.

PATIENTS AND METHODS

We retrospectively reviewed 1000 consecutive colorectal ESD cases (April 2006 to January 2017). Since 2016, the PCM was performed in 58 cases. The indications for ESD included (1) tumors ≥ 20 mm in size diagnosed as intramucosal cancer or high-grade dysplasia and part of T1a cancer using magnifying endoscopic examinations and (2) tumors that appeared impossible to resect with endoscopic mucosal resection because of suspected fibrosis. We identified 120 cases with severe fibrosis and compared them to cases without severe fibrosis. Additionally, the 120 severe fibrosis cases were divided into the PCM and non-PCM groups. En bloc resection, procedure time, discontinuation, and complications were analyzed between these 2 groups.

RESULTS

 Among all 1000 ESDs, severe fibrosis and discontinuation rates were 12.0 % (120 cases) and 1.8 % (18 cases), respectively. Regarding the comparison between cases with severe fibrosis and with no severe fibrosis, there were significant differences about en bloc resection rate (78.3 % vs. 95.7 %, P  < 0.001), discontinuance rate (12.5 % vs. 0.3 %, P  < 0.001), and perforation rate (8.3 % vs. 2.6 %, P  = 0.001). Among the 120 cases with severe fibrosis, 21 and 99 cases were in the PCM and non-PCM groups, respectively. The PCM group had a higher en bloc resection rate (95.2 vs. 74.7, P  =  0.03), a shorter mean procedure time (min) (79.6 ± 26.5 vs. 118.8 ± 71.0, P  = 0.001), and no cases of discontinuation. An analysis of the interobserver agreement for the diagnosis of severe fibrosis among the 3 endoscopists showed kappa values of > 0.6.

CONCLUSIONS

 In cases with severe fibrosis, the PCM with ESD improved en bloc resection rates and shortened the procedure time compared to the conventional non-PCM method. Additionally, the PCM reduced the discontinuation rate.

A novel lens cleaner to prevent water drop adhesions during colonoscopy and esophagogastroduodenoscopy

BACKGROUND AND STUDY AIMS

 Water drop adhesions (WDA) impair endoscopic view during gastrointestinal endoscopy. We developed a novel lens cleaner designed using two types of harmLess surfactants and it is reported to be useful for preventing lens cloudiness during colorectal ESD. In the current study, we examined the ability of it for preventing and removing WDA.

PATIENTS AND METHODS

 During laboratory experiments, the cleaner (Cleash; Fujifilm Co., Tokyo, Japan and Nagase Medicals Co., Hyogo, Japan) was applied to the endoscopic lens and an air/water device (AWD) (water 200 mL, dimethicone 1 mL, Cleash 1 mL). The endoscope was submerged in water 100 times for 5 cycles. Rates of WDA were calculated for various groups (lens and AWD with or without Cleash) and compared to a normal cleaner (SL cleaner). During clinical research, 30 colonoscopies and 30 esophagogastroduodenoscopies were analyzed. For the Cleash group, the cleaner was applied to both lens and AWD. The numbers of WDA and WDA with non-rapid removal were calculated, compared to those of the SL cleaner group.

RESULTS

 The mean WDA rate for the Cleash setting (lens: Cleash; AWD: Cleash) was 11.0 %, which was significantly lower than other settings (lens: SL cleaner; AWD: water, 31.0 %; P  < 0.001) (lens: Cleash; AWD: water, 19.0 %; P  < 0.001). Clinical research of colonoscopies indicated that the numbers of WDA (number/15 sec) and WDA with non-rapid removal were 0.38 and 0.17 for the Cleash group and 0.91 and 0.46 for the SL cleaner groups ( P  < 0.001, P  < 0.001). For esophagogastroduodenoscopies, the results were 0.47 and 0.24 for the Cleash group and 0.54 and 0.42 for the SL cleaner group ( P  = 0.72, P  = 0.018).

CONCLUSION

 A clear and beautiful image without WDA is useful not only for routine endoscopy but also, more importantly, for magnifying endoscopy and other endoscopic treatments. The use of Cleash to lens and AWD showed positive results for preventing and removing WDA during laboratory experiments and clinical research involving CS. Additionally, it also showed positive results for the removal of WDA during EGD.

Review of Techniques to Achieve Optical Surface Cleanliness and Their Potential Application to Surgical Endoscopes

A clear visualization of the operative field is of critical importance in endoscopic surgery. During surgery the endoscope lens can get fouled by body fluids (eg, blood), ground substance, rinsing fluid, bone dust, or smoke plumes, resulting in visual impairment. As a result, surgeons spend part of the procedure on intermittent cleaning of the endoscope lens. Current cleaning methods that rely on manual wiping or a lens irrigation system are still far from ideal, leading to longer procedure times, dirtying of the surgical site, and reduced visual acuity, potentially reducing patient safety. With the goal of finding a solution to these issues, a literature review was conducted to identify and categorize existing techniques capable of achieving optically clean surfaces, and to show which techniques can potentially be implemented in surgical practice. The review found that the most promising method for achieving surface cleanliness consists of a hybrid solution, namely, that of a hydrophilic or hydrophobic coating on the endoscope lens and the use of the existing lens irrigation system.

Tips for safety in endoscopic submucosal dissection for colorectal tumors

In Japan, endoscopic submucosal dissection (ESD) becomes one of standard therapies for large colorectal tumors. Recently, the efficacy of ESD has been reported all over the world. However, it is still difficult even for Japanese experts in some situations. Right-sided location, large tumor size, high degree of fibrosis, difficult manipulation is related with the difficulty. However, improvements on ESD devices, suitable strategies, and increase of operators' experiences enable us to solve these problems. In this chapter, we introduce recent topics about various difficult factors of colorectal ESD and the tips such as strategy, devices, injection, and traction method [Pocket-creation method (PCM) etc.].