Outcomes of radiofrequency ablation for anal high-grade squamous intraepithelial lesions

Radiofrequency ablation (RFA) of high-grade squamous intraepithelial lesions (HSIL) is a promising minimally invasive technique but its oncologic and functional outcomes are not well studied. The primary outcome was the efficacy of RFA, and the secondary outcomes were the functional and anatomical anal changes related to RFA.

This was a retrospective analysis of our prospectively collected database of patients who had RFA for HSIL at our institution, between August 2018 and March 2020. To be eligible for RFA, all patients had impairment of their immune function. Targeted ablation was applied in all cases, with 5 overlapping pulsations at the targeted HSILs (delivering 12 J/cm² per application) followed by circumferential, 2-pulsation (12 J/cm²) overlapping anal ablation, to cover the entire anal transition zone. Patients were assessed for recurrence or metachronous disease at 3-month intervals by means of high-resolution anoscopy (HRA) and targeted biopsies. Anorectal manometry, endoanal ultrasound, the 36-Item Short Form and Massachusetts General Hospital-Sexual Functioning Questionnaire (MGH-SFQ) were assessed at baseline and 12 months after intervention.

We included a total of 12 patients with anal HSILs. The mean age was 38.6 (± 7.68) years, and 7 (58.3%) were males. Six were HIV positive, 2 had a primary immunodeficiency disease, and 4 were receiving immunosuppressive therapy. A mean of 2.1 anal HSILs per patient were treated. At 12 months, high-resolution anoscopy showed that 7/12 (58.3%) patients had normal high-resolution anoscopy, 3/12 patients had recurrent HSILs, and 2/12 had a persistent lesion. Those lesions were treated with electrocautery, and reached complete response in the following the 6 months (total of 18 months). In particular, there were no metachronous lesions detected. Patients reported moderate to severe pain during the first 24 h after RFA, but only mild discomfort was present at 30 days. Patients were asymptomatic at their 6- and 12-month visits. RFA was not associated with changes in anorectal manometry or ultrasound examination. The 36-SF survey reported improvement in the general health domain (p = 0.038), while the MGH-SFQ showed improvements in sexual function.

In this study, targeted plus circumferential RFA had a 58.3% efficacy rate for the treatment of anal HSIL in immunocompromised patients, achieving 100% eradication after adding electrocautery ablation. No metachronous lesions were detected. Patients presented relatively mild symptoms after the procedure, no changes in anorectal anatomy or function, and some improvements in their sexual function. These results seem promising in light of the high recurrence reported after HSIL treatment. Larger studies are needed to validate our results.