Anal chromoendoscopy using gastroenterological video-endoscopes: A new method to perform high resolution anoscopy for diagnosing intraepithelial neoplasia and anal carcinoma in HIV-infected patients.

ABSTRACT

Introduction Anal carcinoma represents an increasing problem in HIV-infected patients. Anal intraepithelial neoplasia (AIN), the precursor lesion, is currently diagnosed by high-resolution anoscopy (HRA) using optical magnification derived from gynecological colposcopy. This prospective study evaluates anal chromoendoscopy (ACE) using standard gastroenterological video-endoscopes in diagnosing AIN. Methods After clinical examination, proctoscopy and surface staining with acetic acid followed by Lugol's solution, ACE was performed with a mucosectomy cap on the tip of the endoscope. Biopsy specimens were collected from areas with a pathological staining pattern and from areas with normal appearance; combined results were considered as reference. Results Two hundred eleven HIV-positive patients seen between 2007 and 2013 were evaluated. Of these, 95.7 % were males, and the median age was 45 years. In 86.7 %, the mode of HIV transmission was sex among males. Combination antiretroviral treatment was applied in 75.8 %. The sensitivity of ACE in diagnosing AIN was 0.85, the specificity was 0.55, the positive predictive value was 0.50, and the negative predictive value (NPV) was 0.87. Diagnostic performance increased in individuals with high-grade lesions (NPV 0.99) and in the second study period from 2011 to 2013. Side effects were rare and of minor clinical relevance. Conclusions Anal chromoendoscopy is safe and effective in diagnosing AIN in a population of HIV-infected patients. It is particularly useful for the exclusion of high-grade lesions that have the strongest risk of progression to anal carcinoma. Therefore, ACE may become a valuable new tool to manage AIN and to prevent anal malignancy in HIV-positive patients.