Virtual Colonoscopy (VC) or Computed Tomography Colonoscopy (CTC) is an exciting innovation in imaging technology capable of altering the current diagnostic approach to screening for colorectal cancer and its precursor, the advanced adenoma. You can read more about the procedure here.
VC was first described in 1994, but it was not until the groundbreaking article by Perry Pickhardt, M.D. in December 2003 in the New England Journal of Medicine that conclusively proved it was equal to traditional Optical Colonoscopy (OC) in the diagnosis of polyps and malignancy. Since then, scores of articles have confirmed Virtual Colonoscopy’s reliability and superiority.
The main points in favor of VC are as follows:
1. MINIMALLY INVASIVE
It is a minimally invasive procedure with a soft rubber catheter being inserted into the rectum. The colon is inflated with carbon dioxide and not room air. This difference between VC and OC means the patient suffers from only minimal abdominal discomfort as CO2 is rapidly absorbed from the gastrointestinal tract and is exhaled, so there is no post-procedural distension or the necessity to pass gas. A typical patient is able to return to work within 30 minutes; no workday is lost and no chaperone is required to drive the patient to and from the x-ray department.
2. NO ANESTHESIA
No anesthesia is required!
3. NOT A SINGLE CASE OF PERFORATION REPORTED
There has not been a single case of perforation reported in those diagnostic centers using a thin soft rectal tube as well as continuous infusion of CO2. This is in direct contrast to OC, where bowel perforation occurs with a frequency of 1 in 500 cases to 1 in 1000 cases. Bowel perforation can lead to surgery, and even partial tissue removal. Even worse, approximately 300 patients die each year as a direct result of the OC procedure.
4. OK IF YOU ARE ON ANTI-COAGULANTS (BLOOD THINNERS)
For patients who are on blood thinners such as Warfarin or Plavix, there is no need to discontinue medication before a VC procedure.
5. NO DANGER OF INFECTION
There is no danger of infecting the patient, since each rectal tube is discarded following the procedure. Conversely, the colonoscope used for OC is used a few thousand times before being replaced. It cannot be heat sterilized because of the fiber-optics, so it's instead immersed in an antiseptic solution that needs to be replaced after every study. If the solution is not properly disposed, there's s a significant risk in contracting Hepatitis B or C, and even HIV.
6. ALWAYS SEE THE ENTIRE LARGE BOWEL (COLON)
A VC can always examine the proximal large bowel even in cases of obstructive cancer of the L colon, where a colonoscope cannot be passed beyond the obstruction.
7. VISUALIZE THE EXTRA-COLONIC ORGANS
VC is able to visualize all of the surrounding organs in the abdomen and pelvis during the procedure. Many tumors outside the colon are identified as well as conditions such as renal calculi, gallstones, fibroids, inguinal and hiatal hernias.
8. EXTREMELY LOW DOSE RADIATION
The total dose delivered is almost always less than the annual background radiation dose of 5 mSv.
9. NO UNNECESSARY REMOVAL OF DIMINUTIVE POLYPS (5MM OR LESS)
While VC cannot remove any of the polyps it may find during the procedure, it's important to understand the risks involved with removal.
Only 6% of asymptomatic average risk individuals will have a polyp greater than 1cm (10 mm), which does require removal, 94% of all cases will be normal, for both VC and OC procedures. The only difference will be that all polyps will be removed during an OC procedure and sent for histology, thus incurring unnecessary costs.
We recommend to our patients with 1-2 polyps measuring 6-9 mm a 3-year follow-up VC to assess if any growth has occurred during that time. For polyps 5 mm or less, they are essentially of no practical clinical significance and best are left alone. The risk of perforating the bowel is greater in these cases than leaving the polyp alone.
INDICATIONS FOR VIRTUAL COLONOSCOPY
Screening of all asymptomatic individuals with low risk of colorectal cancer and over the age of 50.
Screening of asymptomatic patients with a positive family history.
Screening of asymptomatic patients at increased risk for colonoscopy.
Incomplete or failed colonoscopy. Failure to reach the cecum occurs in 2-10% of all colonoscopies.
Patients on blood thinners do not have to discontinue their medication prior to this exam.
Patients who have had previous abdominal and pelvic surgery.
Patients 70 years and older in view of increased anesthesia complications in the elderly.
CONTRA-INDICATIONS FOR VIRTUAL COLONOSCOPY
Inflammatory bowel disease such as ulcerative colitis and Crohn’s Disease.
Any symptomatic acute colitis.
Recent biopsy or polypectomy.
Acute diverticulitis (must wait 6-8 weeks).
Recent colorectal surgery.
Known or suspected perforation.
Call our VC specialists today at (310) 945-2662 to make an appointment.