What is High Resolution Anoscopy (HRA)?
High Resolution Anoscopy, or HRA, is a procedure that allows for examination and evaluation of the anal canal. Using a small thin round tube called an anoscope, the anal canal is examined with a high resolution magnifying instrument called a colposcope. Application of a mild acidic liqud onto the anal canal facilitates evaluation of abnormal tissue such as anal dysplasia. If indicated, a biopsy can be obtained. A digital rectal examination is also done at the time of the procedure. The procedure generally lasts about 15 minutes. It is usually very well tolerated with mild if any discomfort. Significant risks such as bleeding or infection are extremely rare. Note should be taken that HRA is very different from colonoscopy or flexible sigmoidoscopy, neither of which can adequately examine the anal canal for the problems being detected by HRA. No bowel prep is needed for this examination.
Who needs a High Resolution Anoscopy?
The procedure is used in the treatment and surveillance of anal dysplasia and the prevention of anal cancer. It is performed on patients with an abnormal anal cytology or anal Pap test. Anal Pap tests are obtained on individuals who are at risk for genital or anal HPV (Human PapillomaVirus) infections, even in the absence of signs or symptoms of infection.
What do the Biopsy Results Mean?
If your provider obtained biopsies during the HRA, these results will come back as:
- Normal biopsy - There is no evidence of abnormal changes in the sample
- Low-grade dysplasia - This result means mild or low-grade dysplasia or anal warts; these are low risk changes
- High-grade dysplasia - This result means severe or high-grade dysplasia. All or most of the cells in the sample may be pre-cancerous
Learn more about abnormal anal pap smear, anal dysplasia and anal cancer.
Learn more about HPV and Anal Cancer