Background: Anal intraepithelial neoplasia (AIN) (or low/high grade squamous intraepithelial neoplasia (L/HSIL)) is the precursor of anal of early invasive anal cancer. Different treatment options for local ablation of localized lesions have been reported. The aim of this study was to analyze the clinical efficacy and safety of infrared coagulation for the treatment of anal dysplasia.
Methods: A search of the literature was performed in 2019 using PubMed and Cochrane to identify all eligible trials published reporting data on the treatment of anal dysplasia with infrared coagulation. The percentage of squamous cell carcinoma of the the anus that developed in the follow-up and results on major complications after treatment were the primary outcomes.
Results: Twenty-four articles were identified from which 6 were selected with a total of 360 patients included, with a median age of 41.8 years. Three studies were prospective and 3 retrospective, only one was a randomized trial. All articles included males, 4 articles included HIV-positive women and only one article included non HIV infected males. No patient developed major complications after infrared coagulation therapy. Pain was the most common symptom found after the procedure in the different series and mild bleeding that did not require transfusion was the most common complication occurring in 4 to 78% of patients. Median follow-up was between 4.7 and 69 months. No patient developed squamous cell carcinoma after infrared treatment. Recurrent HSIL varied from 10 to 38%. Two studies reported results from follow-up of untreated patients showing that between 72 and 93% of them had persistent HSIL at last follow-up and 4.8% developed squamous cell carcinoma.
Conclusions: Infrared coagulation is a safe and effective method for ablation of high-grade anal dysplasia that could help prevent anal cancer. Continued surveillance is recommended due to the risk of recurrence.
Keywords: Anal dysplasia; Anal intraepithelial neoplasia; High resolution anoscopy; Infrared coagulation.