A Single-Center Pilot Study of Circumferential Anal Canal Radiofrequency Ablation (RFA) to Treat Anal High-Grade Dysplasia

Abstract

Background. HIV-positive (HIV+) individuals are at high risk for anal high-grade squamous intraepithelial lesions (HSILs), the cancer precursor. Most dysplasia occurs at the squamocolumnar junction (SCJ). Targeted HSIL ablation can decrease progression to cancer, but recurrence remains high. Circumferential RFA for esophageal dys-plasia is safe, decreasing dysplasia recurrence over that of targeted ablation. We endeavored to determine whether this is true in the anus. Methods. A prospective trial investigated efficacy of circumferential anal RFA using BarrxTM 60 focal catheters (Medtronic) in subjects with ≥1 anal SCJ HSIL. The entire SCJ was ablated (3 × 12 J/cm2 per site) to treat baseline and occult HSIL (s). A post-RFA biopsy was taken. Subjects were assessed with high-resolution ano-scopy at 3, 6, 9, and 12 months. Mandatory lesion-site biopsies occurred at month 12. Recurrence was retreated with focal RFA. Results. Ten males (9 HIV+), median age 52 years, enrolled. Median T-cell count and viral load were 730 cells/μ L and 38 copies/mL. Median years with HIV were 24.5. At baseline, subjects had a mean 2.7 HSILs (range 2-8 HSILs). Median time for treatment was 6.5 minutes (range 5-13 minutes). Lesion persistence occurred in 4 subjects (3 at 3 months, 1 at 6 months). Recurrence at a new site (metachronous) occurred in 1 subject at 3 months. No lesion persisted after retreatment. All subjects were dysplasia free at 12 months. Immediate post-RFA biopsy of treated lesions showed dysplasia in 50%, and 2 recurred. Eight subjects were healed by 3 months, and 1 each had asymptomatic granulation tissue and superficial erosion. All healed by 9 months. Two device-related mild adverse events (AEs) occurred in 1 subject each (externally thrombosed hemorrhoid and soft anal stricture). Both resolved conservatively (stricture dilated in office with an anoscope). No serious AE occurred. Conclusion. Circumferential anal canal RFA is safe and quick, producing total HSIL eradication with ≤2 treatments. The depth of destruction might be inadequate with only 1 treatment. A second targeted focal ablation resulted in no further dysplasia. Metachronous recurrence is rare. Circumferential RFA appears more effective than targeted ablation, especially in HIV+ subjects, and obviates the need to identify all lesions.