The Colorectal Cancer Coalition: reflections on the future

Screening colonoscopy: The present and the future

In the United States, colorectal cancer (CRC) is the second leading cause of mortality in men and women. We are now seeing an increasing number of patients with advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age, which requires earlier screening. With the increasing need for CRC screening through colonoscopy, and thus endoscopists, easier and simpler techniques are needed to train proficient endoscopists. The most widely used approach by endoscopists is air insufflation colonoscopy, where air distends the colon to allow visualization of the colonic mucosa. This technique is un-comfortable for patients and requires an anesthetist to administer sedation. In addition, patients commonly complain about discomfort post-op as air escapes into the small bowel and cannot be adequately removed. Current research into the use of water insufflation colonoscopies has proved promising in reducing the need for sedation, decreasing discomfort, and increasing the visibility of the colonic mucosa. Future direction into water insufflation colonoscopies which have shown to be simpler and easier to teach may increase the number of proficient endoscopists in training to serve our aging population.

Robotics in Colonoscopy

Colorectal cancer is the second leading cause of mortality in men and women in the United States. While there is a definite advantage regarding the use of colonoscopies in screening, there is still a lack of widespread acceptance of colonoscopy use in the general public. This is evident by the fact that up to 75% of patients diagnosed with colorectal cancer present with locally advanced disease. In order to make colonoscopy and in turn colorectal cancer screening a patient friendly and a comfortable test some changes in tool are necessary. The conventional colonoscope has not changed much since its development. There are several new advances in colorectal screening practices. One of the most promising new advances is the advent of robotic endoscopic techniques.

Analyzing proteasomal subunit expression reveals Rpt4 as a prognostic marker in stage II colorectal cancer

Colorectal cancer is a leading cause of cancer-related deaths worldwide. Early diagnosis and treatment of colorectal cancer is the key to improving survival rates and as such a need exists to identify patients who may benefit from adjuvant chemotherapy. The dysregulation of the ubiquitin-proteasome system (UPS) has been implicated in oncogenesis and cancer cell survival, and proteasome inhibitors are in clinical use for a number of malignancies including multiple myeloma. In our study, we examined the protein expression of several key components of the UPS in colorectal cancer using immunohistochemistry to determine expression levels of ubiquitinylated proteins and the proteasomal subunits, 20S core and Rpt4 in a cohort of 228 patients with colon cancer. Multivariate Cox analysis revealed that neither the intensity of either ubiquitinylated proteins or the 20S core was predictive in either Stage II or III colon cancer for disease free survival or overall survival. In contrast, in Stage II patients increased Rpt4 staining was significantly associated with disease free survival (Cox proportional hazard ratio 0.605; p = 0.0217). Our data suggest that Rpt4 is an independent prognostic variable for Stage II colorectal cancer and may aid in the decision of which patients undergo adjuvant chemotherapy.

Propeller-based wireless device for active capsular endoscopy in the gastric district

An innovative approach to active locomotion for capsular endoscopy in the gastric district is reported in this paper. Taking advantage of the ingestion of 500 ml of transparent liquid by the patient, an effective distension of the stomach is safely achieved for a timeframe of approximately 30 minutes. Given such a scenario, an active swallowable capsule able to navigate inside the stomach thanks to a four propeller system has been developed. The capsule is 15 mm in diameter and 30 mm in length, and it is composed of a supporting shell containing a wireless microcontroller, a battery and four motors. The motors enable the rotation of propellers located in the rear side of the device, thus obtaining a reliable locomotion and steering of the capsule in all directions in a liquid. The power consumption has been properly optimized in order to achieve an operative lifetime consistent with the time of the diagnostic inspection of the gastric district, assumed to be no more than 30 minutes. The capsule can be easily remotely controlled by the endoscopist using a joystick together with a purposely developed graphical user interface. The capsule design, prototyping, in vitro, ex vivo and preliminary in vivo tests are described in this work.

Development of a colon endoscope robot that adjusts its locomotion through the use of reinforcement learning

PURPOSE

Fibre optic colonoscopy is usually performed with manual introduction and advancement of the endoscope, but there is potential for a robot capable of locomoting autonomously from the rectum to the caecum. A prototype robot was designed and tested.

METHODS

The robot colonic endoscope consists in a front body with clockwise helical fin and a rear body with anticlockwise one, both connected via a DC motor. Input voltage is adjusted automatically by the robot, through the use of reinforcement learning, determining speed and direction (forward or backward).

RESULTS

Experiments were performed both in-vitro and in-vivo, showing the feasibility of the robot. The device is capable of moving in a slippery environment, and reinforcement learning algorithms such as Q-learning and SARSA can obtain better results than simply applying full tension to the robot.

CONCLUSIONS

This self-propelled robotic endoscope has potential as an alternative to current fibre optic colonoscopy examination methods, especially with the addition of new sensors under development.

Feasibility proof of a legged locomotion capsule for the GI tract

BACKGROUND

A colonoscopy and a gastroscopy are the most important screening measures for malignant diseases in the GI tract. One of the main limitations is the lack of patient adherence to come in for a flexible endoscopy, especially in asymptomatic conditions.

OBJECTIVE

The feasibility proof of a new generation of endoscopic capsules based on a novel propelling mechanism that features electromechanical legs.

DESIGN

Teleoperated endoscopic 8-legged capsule.

SETTING

Scuola Superiore Sant'Anna, Pisa, Italy, and novineon Healthcare Technology Partners GmbH, Tübingen, Germany.

MAIN OUTCOME MEASUREMENTS

Successful locomotion in a lower-GI tract (LGI) phantom model and in a porcine colon.

RESULTS

The testing session was organized into repetitive ex vivo trials and in vivo tests. The repetitive tests were performed for collecting reproducible data in various small series of individual experiments in standardized conditions, thus defining the best locomotion parameters. In vivo tests were performed in a porcine colon: the capsule, inserted transanally, traveled upward in the oral direction for 15 cm in about 5 minutes, against peristalsis.

LIMITATIONS

The current version of the capsule travels curves by bouncing back from the wall and following step by step the direction of the curved bowel. Steering mechanisms are not yet implemented.

CONCLUSIONS

This study shows the systematic development and medical assessment of an imaging capsule with self-propelling abilities. A full colonic passage was successfully demonstrated in the ex vivo phantom model. A net movement in in vivo tests has been achieved, thus giving a feasibility proof of the legged locomotion as a possible solution to the problem of self-locomoting endoscopic devices in the LGI.