Water exchange versus air insufflation for colonoscopy: A meta-analysis

Clinical value of sigmoid colon water exchange colonoscopy: a prospective randomized clinical trial

This prospective randomized controlled trial investigated the clinical value of sigmoid colon water exchange (SWE) colonoscopy by comparing it with air insufflation (AI) colonoscopy in terms of the patient's pain score, insertion time, and screening quality. Consecutive patients who underwent colonoscopy without sedation were randomized into an AI group (n = 267) or an SWE group (n = 255). Patient characteristics, history of abdominal or pelvic surgery, maximum pain score, insertion time, cecal intubation rate, polyp detection rate, and the need for maneuvers were recorded. There was no significant between-group difference in insertion time, cecal intubation rate, assisted maneuvers (abdominal pressure, changing patients' position), or polyp detection rate (P > 0.05). The mean maximum pain score was significantly lower in the SWE group than in the AI group. (3.57 ± 2.01 vs. 4.69 ± 1.83, P < 0.001). For patients with a history of abdominal or pelvic surgery and those who were overweight (body mass index > 24), the maximum pain scores were lower in the SWE group than in the AI group (3.67 ± 1.95 vs. 4.88 ± 1.80, P < 0.001; 3.40 ± 1.96 vs. 4.79 ± 1.97, P < 0.001, respectively). SWE colonoscopy can significantly reduce abdominal pain with non-inferior screening quality and does not increase insertion time.Trial registration number: ChiCTR2200059057 (date April 23, 2022).

Protocol design for randomized clinical trial to compare underwater cold snare polypectomy to conventional cold snare polypectomy for non-pedunculated colon polyps of size 5-10 mm (COLDWATER study)

BACKGROUND

Colorectal cancer is internationally the third leading cause of death from a malignant disease. The aim of screening colonoscopy in adults > 45 years of age is early diagnosis and treatment of precancerous polyps. Endoscopic polyp removal (polypectomy) can be achieved with various techniques depending on the size, morphology, and location of the polyp. According to current guidelines, small non-pedunculated polyps should be removed with a cold snare after the colorectal lumen has been insufflated with air (conventional cold snare polypectomy).In recent years, several studies have described the benefits of water aided colonoscopy, as well as the safety and efficacy of underwater cold snare polypectomy for large colon polyps. However, there are insufficient data on conventional and underwater techniques for small polyps, the most commonly diagnosed colorectal polyps.

METHODS

We have designed a prospective randomized double-blind clinical trial to compare the safety and efficacy of conventional and underwater cold snare polypectomy for non-pedunculated polyps 5-10 mm in size. A total of 398 polyps will be randomized. Randomization will be carried out using the random numbers method of Microsoft Excel 2016. The primary endpoint is the muscularis mucosa resection rate. Secondary endpoints are the depth and percentage of R0 excisions, complications, and the recurrence rate at follow-up endoscopy 6-12 months after polypectomy.

DISCUSSION

We hypothesize underwater polypectomy will result in a higher muscularis mucosa resection rate. The results of our study will provide useful data for the development of guidelines in polypectomy techniques for non-pedunculated polyps 5-10 mm in size.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT05273697.

Colonoscopy skills improvement training improves patient comfort during colonoscopy

INTRODUCTION

We aimed to assess the effect of Colonoscopy Skills Improvement (CSI) training on patient comfort and sedation-related complications during colonoscopy.

METHODS

This retrospective cohort study was performed on 19 endoscopists practicing in a Canadian tertiary care center who completed CSI training between October 2014 and May 2016. Data from 50 procedures immediately prior to, immediately after, and eight months following CSI training were included for each endoscopist. The primary outcome variable was intraprocedural comfort, and secondary outcomes included intraprocedural hypotension and hypoxia. Data were extracted from an electronic medical record and analyzed using SPSS version 20.0. Univariate analysis and stepwise multivariable logistic regression were performed to determine if there was an association between patient comfort and CSI training. Predictors of these outcomes including patient age, gender, sedation use and dosing, procedure completion, quality of bowel preparation, endoscopist experience, and specialty were included in the analysis.

RESULTS

2533 colonoscopies were included in the study. The mean dose of sedatives was reduced immediately following CSI training and at 8 months for both Fentanyl (75.4 mcg v. 67.8 mcg v. 65.9 mcg, p < 0.001) and Midazolam (2.57 mg v. 2.27 mg v. 2.19 mg, p < 0.001). The percentage of patients deemed to have a comfortable exam improved following endoscopist participation in CSI training and remained improved at 8 months (55.1% v. 70.2% v. 69.8%, p < 0.001). No significant change in rates of intraprocedural hypoxia or hypotension were noted following CSI training.

CONCLUSION

CSI training is associated with improved patient comfort and reduced sedation requirements during colonoscopy.

A review of water exchange and artificial intelligence in improving adenoma detection

Water exchange (WE) and artificial intelligence (AI) have made critical advances during the past decade. WE significantly increases adenoma detection and AI holds the potential to help endoscopists detect more polyps and adenomas. We performed an electronic literature search on PubMed using the following keywords: water-assisted and water exchange colonoscopy, adenoma and polyp detection, artificial intelligence, deep learning, neural networks, and computer-aided colonoscopy. We reviewed relevant articles published in English from 2010 to May 2020. Additional articles were searched manually from the reference lists of the publications reviewed. We discussed recent advances in both WE and AI, including their advantages and limitations. AI may mitigate operator-dependent factors that limit the potential of WE. By increasing bowel cleanliness and improving visualization, WE may provide the platform to optimize the performance of AI for colonoscopies. The strengths of WE and AI may complement each other in spite of their weaknesses to maximize adenoma detection.

Comparison of application value between conventional air insufflation and water infusion in colonoscopy

OBJECTIVE

To discuss the feasibility of water infusion colonoscopy and its difference with traditional air insufflation colonoscopy in application value.

METHODS

A prospective randomized controlled clinical study was designed to include 200 patients who underwent sedation-free diagnostic colonoscopy. Among them, 100 patients were treated with water infusion colonoscopy (observation group) and 100 patients were treated with air insufflation colonoscopy (control group). All operations were performed independently by the same experienced physician. The differences in colonoscopy related values, colon adenoma detection rate, and follow-up findings between the patients of two groups were compared.

RESULTS

There was no significant difference in the Boston bowel preparation scale (BBPS) score of the left hemicolon, transverse colon, right hemicolon, total BBPS scores, and bubble amount between the two groups (P>0.05). In the observation group, the scope-forward time, the time to reach the ileocecal junction, and the total operation time were significantly longer than that of the control group (P<0.01). The proportion of patients in whom the ileocecal junction was successfully reached was significantly higher in the observation group. The intraoperative abdominal pain visual analog scale (VAS) score, abdominal distension VAS score, the proportion of postural change, and the proportion of abdominal compression were all significantly lower in the observation group (P<0.05). There were no significant differences in the endoscope hardness adjustment rate, the scope withdrawal time, total detection rate of adenomas, and the size or location of colon adenomatous lesions between the two groups (P>0.05). Compared with control group, the incidence of abdominal pain and VAS scores were significantly lower in the observation group (P<0.05), and the willingness of patients to perform colonoscopy again was significantly higher (P<0.01).

CONCLUSION

Patients' tolerance and examination satisfaction are significantly better when using water infusion colonoscopy compared with traditional air insufflation colonoscopy, but the operation times are longer.

Optical imaging technology in colonoscopy: Is there a role for photometric stereo?

Colonoscopy screening for the detection and removal of colonic adenomas is central to efforts to reduce the morbidity and mortality of colorectal cancer. However, up to a third of adenomas may be missed at colonoscopy, and the majority of post-colonoscopy colorectal cancers are thought to arise from these. Adenomas have three-dimensional surface topographic features that differentiate them from adjacent normal mucosa. However, these topographic features are not enhanced by white light colonoscopy, and the endoscopist must infer these from two-dimensional cues. This may contribute to the number of missed lesions. A variety of optical imaging technologies have been developed commercially to enhance surface topography. However, existing techniques enhance surface topography indirectly, and in two dimensions, and the evidence does not wholly support their use in routine clinical practice. In this narrative review, co-authored by gastroenterologists and engineers, we summarise the evidence for the impact of established optical imaging technologies on adenoma detection rate, and review the development of photometric stereo (PS) for colonoscopy. PS is a machine vision technique able to capture a dense array of surface normals to render three-dimensional reconstructions of surface topography. This imaging technique has several potential clinical applications in colonoscopy, including adenoma detection, polyp classification, and facilitating polypectomy, an inherently three-dimensional task. However, the development of PS for colonoscopy is at an early stage. We consider the progress that has been made with PS to date and identify the obstacles that need to be overcome prior to clinical application.