EXTRCORPOREAL ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EN BLOC RESECTION OF ANAL SQUAMOUS NEOPLASM

There are numerous small series and case reports of ESD for anal squamous lesions. However, the reported lesions did not extend beyond the anal canal and were removed by traditional ESD. We report the first case of extracorporeal ESD. A technique that allows en bloc resection of an anal lesions extending beyond the anal canal onto the anoderm. The technique consists of holding the endoscope like a Bovie cautery pencil during dissection. The endoscope, unlike a Bovie pencil, conveniently offers illumination, magnification & irrigation in addition to electrosurgical dissection. A distal cap attachment is not needed since the operating hand is stabilized by resting on the patient’s perianal area. Traction can be easily applied by the operator or assistant with a clamp/hemostat or even manually as shown on the video. Case: A 63 year-old woman had colonoscopy that found a 5 cm flat polyp in the rectum. Biopsies revealed: Anal squamous and glandular mucosa with focal high grade anal squamous intraepithelial neoplasia (AIN 2) in background of low grade anal squamous intraepithelial neoplasia (AIN 1). The patient reported that she “was told of Human Papilloma Virus (HPV) on gynecologic exams since the 1980s”. She was referred to us for endoscopic resection of the rectal lesion. Three techniques are illustrated in this video. For the verrucous distal part of the lesion at the anal verge the innovative “extracorporeal ESD” approach is illustrated (the main focus of this video). For the mid portion of the lesion ensconced in the anal canal, standard “pocket” and “underwater” ESD techniques are shown. For the proximal part of the lesion in the rectum, standard traction-assisted ESD technique with clips+rubber band is shown. The ESD was completed in 3.2 hours. There was no postoperative pain. This may have been due in part to injection of 10 cc 0.25% bupivacaine during the extracorporeal ESD. The patient was observed in house for 2 days. There were no adverse events. Pathology showed en bloc resection of high grade anal squamous intraepithelial lesion (AIN 2) in a background of anorectal mucosa with low grade anal squamous intraepithelial lesion (AIN 1). Margins of resection were negative (R0 resection). Follow-up anoscopy and proctoscopy was performed at 6-12 month intervals by an expert colorectal surgeon. Last follow-up at two years showed no recurrence or other lesions. In conclusion, we present a technique of extracorporeal ESD that is helpful in achieving complete en bloc resection of challenging squamous neoplastic lesions with distal extension beyond the dentate line onto the anoderm. The technique illustrates the great versatility of the endoscope which can be used as a monopolar dissection instrument with the additional benefits of illumination, magnification and irrigation.