Objective The optimal approach for removing large laterally spreading lesions at the anorectal junction (ARJ-LSLs) is unknown. Endoscopic mucosal resection (EMR) is a definitive therapy for colorectal LSLs. It is unclear whether it is an effective modality for ARJ-LSLs. Design EMR outcomes for ARJ-LSLs (distal margin of ≤20 mm from the dentate line) in comparison with rectal LSLs (distal margin of >20 mm from the dentate line) were evaluated within a multicentre observational cohort of LSLs of ≥20 mm. Technical success was defined as the removal of all polypoid tissue during index EMR. Safety was evaluated by the frequencies of intraprocedural bleeding, delayed bleeding, deep mural injury (DMI) and delayed perforation. Long-term efficacy was evaluated by the absence of recurrence (either endoscopic or histologic) at surveillance colonoscopy (SC). Results Between July 2008 and August 2019, 100 ARJ-LSLs and 313 rectal LSLs underwent EMR. ARJ-LSL median size was 40 mm (IQR 35–60 mm). Median follow-up at SC4 was 54 months (IQR 33–83 months). Technical success was 98%. Cancer was present in three (3%). Recurrence occurred in 15.4%, 6.8%, 3.7% and 0% at SC1–SC4, respectively. Among 30 ARJ-LSLs that received margin thermal ablation, no recurrence was identified at SC1 (0.0% vs 25.0%, p=0.002). Technical success, recurrence and adverse events were not different between groups, except for DMI (ARJ-LSLs 0% vs rectal LSLs 4.5%, p=0.027). Conclusion EMR is an effective technique for ARJ-LSLs and should be considered a first-line resection modality for the majority of these lesions.

中文翻译：

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内镜下黏膜切除术对肛门直肠交界处的横向扩散病变有效

目的 去除肛门直肠交界处（ARJ-LSL）大的横向扩散病变的最佳方法尚不清楚。内窥镜黏膜切除术 (EMR) 是结直肠 LSL 的最终治疗方法。目前尚不清楚它是否是 ARJ-LSL 的有效方式。与直肠 LSL（距齿状线的远端边缘 >20 mm）相比，ARJ-LSL（距齿状线的远端边缘 ≤ 20 mm）的设计 EMR 结果在 ≥ 20 mm 的 LSL 的多中心观察队列中进行了评估。技术成功被定义为在指数 EMR 期间去除所有息肉状组织。安全性通过术中出血、延迟出血、深部壁损伤 (DMI) 和延迟穿孔的频率进行评估。通过监测结肠镜检查 (SC) 中没有复发（内窥镜或组织学）来评估长期疗效。结果 2008 年 7 月至 2019 年 8 月期间，100 名 ARJ-LSL 和 313 名直肠 LSL 接受了 EMR。ARJ-LSL 中位数大小为 40 毫米（IQR 35-60 毫米）。SC4 的中位随访时间为 54 个月（IQR 33-83 个月）。技术成功率为 98%。癌症存在于三个 (3%) 中。SC1-SC4 的复发率分别为 15.4%、6.8%、3.7% 和 0%。在接受边缘热消融的 30 个 ARJ-LSL 中，在 SC1 处未发现复发（0.0% 对 25.0%，p=0.002）。除了 DMI（ARJ-LSL 0% 与直肠 LSL 4.5%，p=0.027）外，各组之间的技术成功、复发和不良事件没有差异。