Anal intraepithelial neoplasia treated with endoscopic submucosal dissection: a retrospective single-center real-world experience

Aims Malignant tumors originating from the anal canal account for 1-3% of all colorectal cancers, with squamous cell carcinoma (SCC) being the most common type in Western countries [1] [2] [3]. Anal intraepithelial neoplasia (AIN) arises from the anal transition zone and is considered the precursor lesion of SCC [1]. Currently, the standard treatment for AIN is ablation and/or topical agents, such as imiquimod and 5-fluorouracil, yielding less than satisfactory results (40-60% success, anal burning and pain) [1] [2]. Saline-immersion pocket endoscopic submucosal dissection (SP-ESD) is an endoscopic method, during which, after the creation of the submucosal pocket, saline is infused with minimal CO² insufflation, providing natural traction/tension and better visualization [4]. ESD is an emerging technique for the treatment of anal lesions, but the literature mostly comprises case reports [5] [6]. Moreover, there is a lack of a definitive strategy for ESD in this technically demanding site, where common traction methods are rarely used or prove ineffective. In this single-center case-series study, we aim to evaluate the feasibility and safety of SP-ESD for the treatment of AIN in a European center setting.

Methods We conducted a single-center case series study at the University Hospital of Larisa, Greece from January 2023 through November 2024. A total of four patients – 2 females, mean age 67±9 years- were treated for 4 lesions: 2 high-grade and 2 low-grade AIN, mean size 3.2±1.1cm. Procedures were undertaken, using a therapeutic gastroscope, blue dye solution infusion, a 1.5mm ESD knife, a short tapered hood, CO2 insufflation, coagulation forceps and clips for hemostasis or closure. The main outcomes observed were technical success, en bloc and R0 resection rates. Secondary outcomes were bleeding (immediate or delayed), perforation, post-ESD fever, hospitalization duration and stenosis.

Results We observed 100% technical success, 100% R0 resection and 100% curative resection rates. Post-resection histopathology was consistent with 3 high-grade and 1 low-grade AIN. Regarding adverse events, minor intraoperative bleeding occurred in two cases, treated with electrocoagulation and one intraoperative perforation (grade II), which was successfully managed using clips. Post-ESD fever was recorded in 2 cases, and resolved within 24-36 hours. The mean duration of hospitalisation was 2±1 days. No delayed adverse events or stenosis requiring dilatation were recorded during follow-up.

Conclusions ESD, especially SP-ESD is a feasible, effective and safe treatment modality for AIN. Larger multicenter studies are needed, however, prior to a wider adoption.

Conflicts of Interest

Authors do not have any conflict of interest to disclose.

• References

• 1 Sakamoto Τ. et al. Anal Intraepithelial Neoplasia: Precursor of Anal Squamous Cell Carcinoma. J Anus Rectum Colon 2022; 6: 92-99
• 2 Rao S.. et al. Anal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol 2021; 32: 1087-1100
• 3 Scholefield JH. et al. Malignant transformation of high-grade anal intraepithelial neoplasia. Br J Surg 2005; 92: 1133-1136
• 4 Harada H. et al. Saline-pocket endoscopic submucosal dissection for superficial colorectal neoplasms: a randomized controlled trial (with video). Gastrointest Endosc 2019; 90: 278-287
• 5 Kasuga K. et al. Impact of ESD of an anal squamous intraepithelial lesion with indistinct border. Endoscopy 2020; 52: E75-E77
• 6 Uozumi T. et al. Endoscopic submucosal dissection for early squamous cell carcinoma in the anal canal and Lugol chromoendoscopy for assessment of the lateral margin. Endosc Int Open 2018; 6: E1130-E1133

Publikationsverlauf

Artikel online veröffentlicht:
27. März 2025