Virtual Colonoscopy as Effective as Traditional Colonoscopy

Virtual Colonoscopy for Older Patients

The February 23rd issue of Radiology reported research conducted by a Mayo Clinic doctor that showed that “virtual colonoscopy” has the same diagnostic benefits as the standard colonoscopy procedure when performed in people over 65 years old.  Virtual colonoscopy is known more technically as computerized tomographic CT colonography.

In 2008, the New England Journal of Medicine published about a study concluding that effectiveness of virtual colonoscopy is no different from a standard one, but it did not assess the procedures’ effect on older patients.  The Mayo Clinic study supported the study further, with emphasis on those who are over 65 years old.

Results of the study collected by Chair of the Department of Radiology, C. Daniel Johnson, M.D., and his associates suggests that virtual colonoscopy can now be viewed as a procedure for everyone, young and old.
The reason why colonoscopies are done is to check whether patients have pre-cancerous growths (adenomatous polyps) or other conditions inside the colon.  Colonoscopy screening is recommended for those who have turned 50, especially when the patient’s family has a known history of colon cancer problems.

Standard Colonoscopy vs. Virtual Colonoscopy

The colonoscopy procedure involves the insertion of a thin flexible tube through the rectum. A small camera at the end of the tube sends images of polyps and other problems inside the bowel for the doctor to see. Colonoscopy preparation consists of taking laxatives before the procedure.  Usually a person is also sedated before a colonoscopy.  There is no need for a hospital stay after getting screened. A doctor removes any detected polyps using a wire loop that can pass through the tube used during standard colonoscopies, which carries an increased risk of bowel perforation.

Virtual colonoscopy preparation still requires cleaning out the colon with laxatives, but they do not require sedation or tube insertion. Instead, nominal placement of an enema tip through the rectum allows carbon dioxide to be pumped into the large intestine in order to inflate it.  The patient is then passed through a CT machine for a series of x-rays.  The images are then made into 3D images of the rectum and colon, which can be examined by a radiologist.

The 2008 NEJM research showed that virtual colonoscopy is as effective as the standard colonoscopy procedure, but it did not differentiate between age groups.  The new study done by the Mayo Clinic team not only supported the previous study but also concluded that virtual colonoscopy works well in patients of all ages. Specifically, 2,600 subject patients over the age of 50 were subjected to both methods of colonoscopy in 15 gastroenterology facilities around the US.  Results of their tests showed that virtual colonoscopy had precise readings for 6 to 9mm sized polyps and those above 1 cm.

Concluded Effectiveness of Virtual Colonoscopy

In a press statement, Johnson announced that his team failed to find any statistical difference between diagnostic abilities of colonoscopy and virtual colonoscopy. Johnson said that he deems the findings positively, as now CT colonography can be a viable option for colorectal cancer screening. He also mentioned that only 12 percent of the patients who showed signs of polyps during CT colonography actually needed to follow-up with a regular colonoscopy for polyp removal. Early detection of pre-cancerous polyps and polyp removal is important in stopping cancer from spreading, and screening on a regular basis is the best thing a patient can do to help eliminate colon cancer as a major fatal cancer this country.

Majority of people do not like to undergo colon screening even if they need to because of the invasive procedure and the inconvenience of bowel prep. The less-invasive virtual colonoscopy can be resorted to for those who have a problem with the standard procedure or those who cannot safely undergo standard colonoscopy, such as someone with an obstructed colon or somebody taking anticoagulant medication. A local GI doctor will be able to tell you whether you qualify for either procedure.