Introduction

Currently, colorectal cancer is the second leading cause of death worldwide¹. Therefore, colon cancer screening tests such as colonoscopy and fecal occult blood test (FOBT) are performed to reduce the mortality and incidence of colorectal cancer^2-5. Although FOBT is a simple test, positive patients eventually require colonoscopy to confirm the presence of lesions. Thus, colonoscopy is gold standard to detect and diagnose colon cancer. However, performing a colonoscopy requires a high level of skill in colon insertion, making it challenging for beginner colonoscopists to achieve total colonoscopy. Furthermore, cases involving longer colons and adhesions require even more advanced techniques. Therefore, a new colonoscope that allows safe and easy colon insertion is desired.

Aims & Methods

To simplify colon insertion, a prototype of robotic colonoscope was developed using 3D printer. The device consists of an outer and an inner tube with a balloon and a bending function. Therefore, the mechanism is characterized by the tip of the inner tube being pushed out to the off-axis by tip direction of outer tube. The insertion method is expected to avoid excessive stretching of the intestinal tract. They are independently and electrically manipulated to bend and push/pull using servo motor via a controller, so it has potential to insert total colon alone.
The model was designed with a maximum outer diameter of 14 mm. Therefore, it can insertion test using colon model. In this study, insertion to colon model of case 1 (Colonoscope training model, KYOTO KAGAKU Co., LTD, Japan) was investigated using the developed device.

Results

Investigation of the operation of the developed device confirms that the controller can be used to control bending of the outer and inner tubes, inflation and deflation of balloons attached to the outer and inner tubes, and pushing and pulling of the inner tube. The maximum angles of the outer and inner tubes were approximately 90 and 180 degrees, respectively. The balloons were confirmed to inflate to a diameter of approximately 7 cm, which is sufficient for intestinal fixation. In addition, the tips of the outer and inner tubes could lift up to 200 and 50 g, respectively.
In the insertion test, the device was reached from the anus to the cecum in approximately 440 s by a non-medical operator alone. In addition, the device can be inserted into the colon model without excessive stretching during the test.

Conclusion

In this study, a prototype of robotic colonoscope with double-balloon and double-bend tube was developed to simplify insertion, and it was confirmed well operated properly. In insertion test, the device could be reached to cecum of colon model (Case 1) by non-medical operator alone. In addition, the behavior was free from over-extended colon model, thus, it suggests that the mechanism of prototype can contribute to comfortable colonoscopy.

References

1. Sung, H. et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA: A Cancer Journal for Clinicians 71, 209-249, (2021).
2. Chiu, H. M. et al. Effectiveness of fecal immunochemical testing in reducing colorectal cancer mortality from the One Million Taiwanese Screening Program. Cancer 121, 3221-3229, (2015).
3. Zorzi, M. et al. Impact on colorectal cancer mortality of screening programmes based on the faecal immunochemical test. Gut 64, 784, doi:10.1136/gutjnl-2014-307508 (2015).
4. Nishihara, R. et al. Long-Term Colorectal-Cancer Incidence and Mortality after Lower Endoscopy. New England Journal of Medicine 369, 1095-1105, (2013).
5. Doubeni, C. A. et al. Effectiveness of screening colonoscopy in reducing the risk of death from right and left colon cancer: a large community-based study. Gut 67, 291, (2018).

Introduction

The number of deaths caused by colorectal cancer has been gradually increasing in recent years. However, it is treatable if detected early, with five-year survival rates exceeding 90%. As early-stage cancers are often asymptomatic, regular screening is essential.
Expanding the number of endoscopic examinations requires a corresponding increase in the number of trained endoscopists. A physician shortage hinders large-scale screening. Among the various steps in colonoscopy, the insertion procedure is technically demanding, especially in anatomically complex regions such as the sigmoid colon. Mastery of this step requires considerable training and clinical experience, which poses a significant barrier to scalability.
Under these circumstances, there is a strong demand for simplifying and automating the insertion procedure of colonoscopes.

Aims & Methods

In this study, we aim to address this challenge by developing a motorized double-balloon colonoscope. The colonoscope has a double-tube structure, consisting of an outer and an inner tube. Each tube can be independently bent at the tip using wires, allowing the scope to follow the curves of the colon and navigate complex anatomical regions. The inner tube can move axially within the outer tube, and both tubes are equipped with separate balloons. The alternating inflation and deflation of the balloons, one tube can be fixed while the other advances. This mechanism enables stable and controlled insertion along the intestinal lumen. A single operator can perform the procedure by manipulating the outer tube with one hand and operating a dedicated controller with the other. Additionally, 300 images were extracted and annotated from colonoscope insertion videos. These were used to train a YOLO model capable of detecting the direction of the intestinal lumen, with the aim of assisting in steering during insertion in future applications.

Results

To evaluate the insertion performance of the developed colonoscope, we conducted insertion experiments using a colon model. The procedure began with the inner tube placed inside the outer tube, and the device was inserted from the anus. After passing through the rectum, insertion into highly curved regions such as the sigmoid colon proved difficult using the outer tube alone. Therefore, the tip of the outer tube was aligned with the direction of insertion, the intestinal tract was fixed using a balloon, and the inner tube was advanced.
The bending of the inner tube was manipulated to avoid collision with mucosal folds, allowing the device to reach the descending colon without overstretching the colon wall. By repeatedly alternating balloon fixation and tube advancement, the device proceeded through the transverse and ascending colon, eventually reaching the cecum. This sequence of operations was repeated in three trials, all of which resulted in successful insertion into the cecum. These results demonstrate that the developed device is capable of stable and stepwise insertion throughout the colon, including anatomically complex and highly curved segments.

Conclusion

In this study, we developed a motorized double-balloon colonoscope and a machine learning-based technique for detecting the direction of the intestinal lumen. Insertion experiments using a colon model demonstrated the effectiveness and reliability of the proposed insertion method.
As the next step, we aim to construct a prototype system that integrates these technologies. We also plan to implement robotic arm control that mimics endoscopist hand movements to achieve safe, minimally invasive insertion.

References

Takamatsu, T., Endo, Y., Fukushima, R. et al. Robotic endoscope with double-balloon and double-bend tube for colonoscopy. Sci Rep 13, 10494 (2023). https://doi.org/10.1038/s41598-023-37566-3

Introduction

Screening colonoscopy has become the gold standard in discovery and removal of colonic polyps and prevention of colon cancer. However, in 13.1-25.8% of patients colonoscopy was not completed and cecal intubation was not achieved.^1-3 DiLumen® (Lumendi LLC, Westport CT, USA) double balloon endoscopic platform was developed to facilitate endoscopic interventions in gastrointestinal tract.

Aims & Methods

Aim: To evaluate use of DiLumen® to facilitate difficult colonoscopy.
Methods: DiLumen® is a flexible overtube with 2 balloons on its distal end. One (Aft) balloon is rigidly attached to the overtube and a second (For) balloon can be advanced forward or pulled back using 2 push rods moved by a slider located on the handle of DiLumen®. The assembled platform is pre-loaded on top of any colonoscope and introduced into the rectum. The colonoscope-DiLumen® assembly is advanced through sigmoid into descending colon where Aft-balloon is distended to fix the overtube inside the colonic segment. Then DiLumen® is pulled back to straighten and to shorten the colon. The colonoscope is advanced forward till transverse colon is reached. The Aft balloon is collapsed and DiLumen® is advanced into transverse colon over the colonoscope. The Aft balloon is distended inside the transverse colon and DiLumen® is pulled back now shortening and straightening the left colon. This process is repeated till the cecum is reached.

Results

We reviewed use of DiLumen® to facilitate colonoscopy in 53 patients (25 males, 28 females, mean age 68.0±10.1 years). Prior to referral for DiLumen®-assisted procedure, one colonoscopy attempt was unsuccessful in 31 patients, 19 patients had 2 unsuccessful colonoscopies, 2 patients had 3 unsuccessful colonoscopies and 1 patient had 4 unsuccessful colonoscopy attempts. The most common reasons for failure were long, redundant, torturous colons. DiLumen® effectively straightened and shortened the colon markedly facilitating advancement of the colonoscope and allowing successful examination of the entire colon with cecal intubation in all 53 patients (technical success 100%). Mean time to reach cecum was 13.1±6.8 minutes and total procedure time was 30.6±15.2 minutes. Normal colonic mucosa was seen in 13 patients (24.5%). Majority (75.5%) of patients had significant pathology found: only 1 polyp was found in 14 patients (26.4%), 2 polyps were found in 10 patients (18.9%), 3 and more (up to 9) polyps were found in 16 patients (30.2%). The polyps ranged in size from 3 to 80 mm and were found in all colonic segments from rectum to ileocecal valve.

Conclusion

Endoscopic double balloon interventional platform markedly facilitated colonic straightening and shortening and allowed successful completion of colonoscopy with removal of previously undetected colonic polyps in patients with difficult (long, redundant and torturous) colon and unsuccessful previous colonoscopies.

References

1. Witte TN, Enns R. The difficult colonoscopy. 2007 Aug; 21(8): 487–490.
2. Baxter NN, Goldwasser MA, Paszat L, Saskin R, Urbach DR, Rabeneck L. A population-based case control study of the effectiveness of colonoscopy for prevention of death from CRC. Gastroenterology. 2007;132:A–88.
3. Shah H, Paszat LF, Saskin R, Stukel TA, Rabeneck L. Factors associated with incomplete colonoscopy: A population-based study. Gastroenterology. 2007;132:2297–303.

Introduction

Colonoscopy is the gold standard for diagnostic investigation of the lower gastrointestinal tract. There is a recognised limitation of current colonoscopes in their steering capability and stability they can provide to deliver therapeutic options. Alongside the high risk of pain and discomfort caused both by patients’ factors and also the endoscopists skill and the manual pushing mechanism of the user.
Undertaking a paradigm shift in how we navigate the large bowel and implementing a novel steering technique with a soft growing robotic system can potentially overcome these issues and allow fine control, precise steering and the capability to expand treatment options in colonoscopy further.
This study assesses a novel self-propelling soft robot against a standard colonoscope in the force that is exhibited on the bowel wall and its clinical implications.

Aims & Methods

A head-to-head study in a hybrid soft and rigid colon phantom resembling the left colon sigmoid was produced. Both the novel soft robot and standard colonoscope were passed through the phantom by 9 clinical endoscopists. Multiple passes were undertaken in the phantom with both colonoscopy methods with force values recorded at two points (end of rectum and end of sigmoid) with pressure sensors recorded. Data collected in MATLAB was then statistically analysed.

Results

9 clinical endoscopists (4M:5M, 2 trainees, 3 JAG certified and 5 expert) undertook this head-to-head trial.
The average force applied with the novel robot to end of rectum was 0.25N and to end of sigmoid was 0.19N. The average force applied with standard colonoscopy to end of rectum was 2.82N and to end of sigmoid 1.45N.
The maximum force applied with the novel robot to end of rectum was 1.31N and to end of sigmoid was 1.35N (SD:0.18). The maximal force applied with standard colonoscopy to end of rectum was 19.03N (SD:2.79) and to end of sigmoid 18.6N (SD:1.38).
The average time for navigating the phantom for the novel robot was 83.5secs (SD:30.8) and 40.5secs (SD:10.1).

Conclusion

This study has demonstrated the novel soft robot does demonstrate significant improvement in force applied both on average and single maximal values when compared to a standard colonoscope which will clinically translate to a significantly more comfortable colonoscopy for a patient. This has substantial positive effects such as reduced or no sedation, better retainment of patients for further procedures and a shallower learning curve to competence for clinical users.
Currently time taken is higher with the novel robot and this can mainly be attributed to the learning curve of the new technology, with improvement seen in each clinician in subsequent passes through the phantom.
Further work will be undertaken in collecting data in a complete soft phantom of an entire colon model as supposed to sections. Aspirational aims will be do then perform animal model testing to gather as close to in-vivo information with this novel soft robot technology.

Introduction

Advancements in colonoscope technology have been identified as one of the factors that can affect the quality of colonoscopy, positively affecting adenoma detection rate (ADR). In recent years, new-generation endoscopic system (video system center and colonoscope) and 4K monitors have been released. These instruments provide endoscopists with higher resolution and lower noise images than previous-generation endoscopic instruments. However, it is unclear whether these new-generation endoscopic instruments can enhance the adenoma detection ability.

Aims & Methods

We aimed to clarify the colorectal adenoma detection ability of new-generation endoscopic instruments by comparing them with previous-generation endoscopic instruments. This study was a retrospective single-center study in patients undergoing screening colonoscopy or surveillance colonoscopy after endoscopic resection or surgical resection for colorectal neoplasm. The X1 group was the group of patients who underwent colonoscopy using new-generation endoscopic instruments (video system center: EVIS X1 CV1500, colonoscope: CF-XZ1200I/CF-EZ1500DI, monitor: 4K) between April 2022 and March 2023. The ELITE group was the group of patients who underwent colonoscopy using previous-generation endoscopic instruments (video system center: EVIS LUCERA ELITE CV290, colonoscope: PCF-H290ZI/CF-HQ290Z, monitor: Full HD) between April 2019 and March 2020. We conducted an analysis for propensity score matched patients using known factors (patient age, sex, purpose of colonoscopy, observation mode, and endoscopists’ expertise) that may have affected the ADR. The patients who were familial adenomatous polyposis, lynch syndrome, or inadequate bowel preparation (Aronchick scale: over 3 score) were excluded. The primary outcome was the ADR. The secondary outcomes were the mean number of adenomas detected per procedure (MAP) and flat polyp detection rate (FDR). We also performed a subgroup analysis comparing ADR, MAP, and FDR by observation mode between white light imaging (WLI) and narrow band imaging (NBI).

Results

480 patients in the X1 group and 1560 patients in the ELITE group were enrolled in this study. After propensity score-matching, 960 patients were finally included in the analysis (480 patients in each group). The patient characteristics were well balanced after propensity score matching between each group. The ADR in the X1 group was significantly higher than that in the ELITE group (55.0% vs 49.0% [McNemar test p=0.049]). The MAP and FDR in the X1 group were also significantly higher than that in the ELITE group (MAP(±SD), 1.52±2.25 vs 1.13±1.77, [Wilcoxon signed rank sum test p=0.004]; FDR, 50.0% vs 39.4%, [p<0.001]). In the subgroup analysis by observation mode, in NBI mode, the MAP in the X1 group was significantly higher than that in the ELITE group (1.52±2.00 vs 1.20±1.83, [Wilcoxon rank sum test p=0.047]). In WLI mode, the FDR in the X1 group was significantly higher than that in the ELITE group (46.3% vs 30.2%, [Fisher’s exact test p=0.0012]).

Conclusion

Our study indicated that the use of new-generation endoscopic instruments improved the colorectal adenoma detection ability.

Introduction

Cancer is the second leading cause of death globally. Colon cancer is the fifth most prevalent type of cancer. Screening, particularly colonoscopy, reduces incidence by 40% and mortality by 50%. The process of bowel preparation before a colonoscopy is complex and requires the patient’s compliance. Enhanced education using a smartphone application has been shown to improve bowel preparation quality. However, heterogeneity was observed among the studies.

Aims & Methods

AIMS: To determine if providing instructions through an application enhances bowel preparation quality in Thai patients undergoing elective colonoscopy.

METHODS: From July 2022 to January 2024, a prospective, endoscopist-blinded, randomized, controlled trial was conducted. Consecutive patients aged > 18 years old who had convenient access to the Line application were randomly assigned in a 1:1 ratio to be educated via the smartphone application (APP group) or the standard education (control group). All patients received the same purgative regimen. The primary outcome was the Boston Bowel Preparation Scales (BBPS). Secondary outcomes included adenoma detection and cecal intubation rates, cecal intubation time, withdrawal time, and patient satisfaction.

Results

The trial aims to recruit 488 patients. A total of 272 patients (APP group, n = 131; control group, n =141) were preliminary analyzed. The mean age was 61.5 years old, and 29% were male. The mean BBPS was comparable between the APP and control groups (8.30 ± 0.99 vs 8.51 ± 1.19, P = 0.173). Both groups achieved adequate bowel preparation (BBPS>6) in 99.2% of cases. All secondary outcomes corresponded with the primary outcome. In the subgroup analysis among the elderly, levels of education, income, and waiting times for colonoscopies, BBPS was not impacted by the providing methods. No adverse events related to education were observed.

Conclusion

Both standard and enhanced education using the smartphone application resulted in excellent bowel preparation. Eligible patients included in this study might influence this outcome. However, using the smartphone application was well-received and could potentially replace standard education for bowel preparation.

References

1. Virani S, Bilheem S, Chansaard W, Chitapanarux I, Daoprasert K, Khuanchana S, et al. National and Subnational Population-Based Incidence of Cancer in Thailand: Assessing Cancers with the Highest Burdens. Cancers. 2017;9(8):108.

2. May FP, Shaukat A. State of the Science on Quality Indicators for Colonoscopy and How to Achieve Them. Official journal of the American College of Gastroenterology | ACG. 2020;115(8):1183-90.

3. Desai M, Nutalapati V, Bansal A, Buckles D, Bonino J, Olyaee M, et al. Use of smartphone applications to improve quality of bowel preparation for colonoscopy: a systematic review and meta-analysis. Endosc Int Open. 2019;7(2):E216-E24.