A novel, autonomously controlled capsule robot, recently tested in colon exploration, may increase patient compliance with colonoscopy by decreasing the pain associated with the procedure and possibly eliminating the need for sedation. The capsule robot is being developed by The STORM (Science and Technology of Robotics in Medicine Lab) at Vanderbilt University, Nashville, TN.
“Many patients avoid colonoscopy, for a number of reasons, including fear of discomfort or sedation,”
Keith Obstein, capsule robot developer, Associate Professor of Medicine and Assistant Professor of Mechanical Engineering at Vanderbilt, told reporters during an interview at Digestive Disease Week (DDW) 2017 in Chicago in May, where preliminary data on the capsule robot were presented. Obstein’s results suggest that in the future, endoscopists could be using a capsule robot for colonoscopies and therapeutic treatments, such as biopsies of tissue or polyp removal.
This technology may be particularly beneficial to IBD patients, as they undergo more frequent colonoscopies for surveillance and other issues. We know that for IBD patients the lifetime risk of complication from colonoscopy is increased based on the number of procedures,” Obstein said.
Currently available colon capsules are limited due to passive movement and lack of therapeutic capability. Due to its 18-millimeter size and the manner in which the external magnet pulls the capsule robot from the front,
“much of the physical pressure that is placed on the patient’s colon would be reduced, making the procedure less uncomfortable and less likely to require the use of sedation,” Obstein said.
Photo courtesy of the Science and Technology of Robotics in Medicine (STORM) Lab
According to the study abstract, this is the first time that a capsule robot has been autonomously controlled in-vivo in a reliable, efficient and safe manner. The capsule robot is maneuvered by magnetic coupling – the capsule head contains an internal permanent magnet and magnetic force and torque are applied by an external permanent magnet manipulated by a robotic arm for teleoperated maneuverability.
The capsule is introduced via the rectum and is soft-tethered, which allows for introduction of instruments, insufflation, irrigation and suction. Software allows for real-time pose detection of the capsule relative to the external magnet so the robot can “think” autonomously for precise movement of the capsule in the colon.
In the initial test of the capsule robot, Obstein’s lab was able to successfully perform autonomous retroflection (Rflx) with the simple “push-of-button” in the colon of a pig in-vivo. Rflx is a common but mechanically complex maneuver performed during colonoscopy and therefore serves as an excellent subject for autonomous control, according to Obstein.
Active autonomous intelligent manipulation of a capsule robot is a breakthrough step toward artificially intelligent endoscopist-directed capsule colonoscopy. Studies evaluating additional control algorithms are currently underway. The first colon exploration trials in humans are scheduled to begin in 2018, according to Obstein.
Colon Cancer Screening and Inflammatory Bowel Disease Surveillance Guidelines
Each year colon cancer claims the lives of more than 600,000 people worldwide and is the fourth leading cause of cancer-related death in the world. Like other cancers, colon cancer progresses to malignancy in approximately 5-10 years; however it possess the unique quality that if the tumor is detected at an early stage, the prognosis for survival is 90%. For this reason it is recommended that people over 50 years of age or people who have a family history of colon cancer undergo routine screenings for colon cancer every five years.
Patients with inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn’s disease, have an increased risk of developing colon cancer. Estimates of this risk in UC vary depending on two main risk factors, including the extent of the disease (how much of the colon has been inflamed) and duration of disease. A family history of colon cancer in a first-degree family member also increases the risk of cancer, particularly if the family member had colon cancer before the age of fifty. Patients who have had UC for more than 10 years and patients with ulcerative pancolitis (disease involving the entire colon) have the highest risk of developing cancer. Patients with left-sided UC have a slightly higher risk of developing CRC than the general population. It is therefore recommended that patients with pancolitis and left-sided UC undergo a screening colonoscopy 8-10 years after the onset of the disease. Routine surveillance colonoscopies should then be performed every 1-2 years. Patients with ulcerative proctitis (disease limited to the rectum) are not considered to be at increased risk of developing CRC and generally do not need to undergo surveillance colonoscopy.
Patients with Crohn’s disease limited to the small intestine are not considered to be at higher risk for CRC than the general population. However, patients with Crohn’s disease who have major colonic involvement (one third or more of the colon) can have up to a 5% risk of developing CRC. Similar to patients with ulcerative colitis, the duration and extent of the disease are major risk factors for developing CRC. It is recommended that patients with Crohn’s disease affecting the colon undergo a screening colonoscopy 8-10 years after the onset of the disease. Routine surveillance colonoscopies should then be performed every 1-2 years similar to patients with ulcerative colitis.
Obstein KL, Valdastri P. The First Autonomously Controlled Capsule Robot for Colon Exploration 2017; DDW Abstract #Mo1962
Obstein KL, Valdastri P. Advanced endoscopic technologies for colorectal cancer screening. World J Gastroenterol 2013; 19(4): 431-439
Itzkowitz, SH, Present, DH, 2010, Colorectal Cancer Screening and Surveillance in Inflammatory Bowel Disease, Gastroenterology, v.138, p. 738-745.
http:// download.journals.elsevierhealth.com/pdfs/journals/0016-5085/ PIIS0016508509022021.pdf