A Safety and Efficacy Trial of Circumferential Anal Canal Radiofrequency Ablation for High-Grade Anal Intraepithelial Neoplasia Using the BARRX™ Anorectal Wand

Inclusion Criteria: 1. Age 18-75 years 2. HRA 2 to 8 weeks prior to the 0 month RFA visit yielding one or more flat, non- condylomatous biopsy-proven HSILs that are * Located entirely within the eligible treatment zone AND * Contiguous with the squamocolumnar junction 3. Eligible treatment zone (ETZ) is defined as * 3 cm above the dentate line to the anocutaneous line AND * Full anorectal circumference 4. If female of child-bearing age, negative pregnancy test within 8 weeks of the 0 month RFA visit and declared intent to remain on birth control throughout the trial, or declaration of infertility defined as subject report of status as post-menopausal or surgically sterile (status post hysterectomy or tubal ligation). 5. If HIV positive * HIV positive on antiretroviral therapy for at least 3 months with laboratory blood work within 12 weeks prior to the 0 month visit demonstrating viral load \< 50 * CD4 count ≥ 250/mm3 * ANC \> 750/mm3 * Platelet count ≥ 75,000/mm3 * Hemoglobin ≥ 9.0 g/dl Exclusion Criteria: 1. Any biopsy-proven HSIL partially outside of the ETZ (for example, an HSIL lesion with extension to the perianal skin) 2. Any condylomas in the eligible treatment zone \> 1/2 cm diameter 3. Any anal or rectal pathology requiring treatment including ulcer, fistula, fissure, or proctitis 4. Any anal stricture or stenosis in patient history or upon examination. 5. Symptomatic scarring in anal canal (i.e. not pliable, hyperkeratosis) 6. History of or present anal or rectal cancer 7. History of pelvic radiation therapy 8. History of HPV vaccination or plans to initiate HPV vaccination during the trial 9. History of ablation or resection therapy within the ETZ within 3 months prior to the 0 month RFA visit (other than cauterization or excision of condylomata) 10. History of topical therapy (e.g. Imiquimod, 5-FU, Trichloroacetic acid) within the ETZ within 3 months prior to the 0 month RFA visit 11. Hemorrhoids \> grade III 12. Fecal incontinence 13. Concurrent disease requiring systemic immunosuppression therapy 14. Concurrent malignancy requiring systemic therapy 15. Life expectancy \< 2 years