BACKGROUND AND AIMS Residual or recurrent adenoma (RRA) is the major limitation of piecemeal EMR (p-EMR) for large colonic laterally spreading lesions (LSLs) ≥20 mm. En bloc EMR (e-EMR) has been shown to achieve low rates of RRA but specific procedural and long-term outcomes are unknown. Our aim was to compare long-term outcomes of size-matched LSLs stratified by whether they were resected e-EMR or p-EMR. METHODS Data from a prospective tertiary referral multicenter cohort of large LSLs referred for EMR over a 10-year period were analyzed. Outcomes were compared between sized-matched LSLs (20-25 mm) resected by p-EMR or e-EMR. RESULTS Five hundred seventy LSLs met the inclusion criteria of which 259 (45.4%) were resected by e-EMR. The risk of major deep mural injury (DMI) was significantly higher in the e-EMR group (3.5% vs 1.0%, P = .05), whereas rates of other intraprocedural adverse events did not differ significantly. Five of 9 (56%) LSLs, with endoscopic features of submucosal invasion (SMI), resected by e-EMR were saved from surgery. RRA at first surveillance was lower in the e-EMR group (2.0% vs 5.7%, P = .04), but this difference was negated at subsequent surveillance. Rates of surgical referral were not significantly different between the groups at either surveillance interval. CONCLUSION When comparing e-EMR against p-EMR for lesions ≤25 mm in size of similar morphology in a large prospective multicenter cohort, e-EMR offered no additional advantage for predicted-benign LSLs. However, it was associated with an increased risk of major DMI. Thus, en bloc resection techniques should be reserved for lesions suspicious for invasive disease. (Clinical trial registration number: NCT01368289.).

中文翻译：

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整体切除对内镜黏膜切除术后长期预后的影响：一项配对队列研究。

背景与目的残余或复发性腺瘤（RRA）是零食EMR（p-EMR）的主要局限性，适用于≥20 mm的大结肠横向扩散病变（LSLs）。整体EMR（e-EMR）已被证明可实现较低的RRA发生率，但具体的手术和长期结果尚不清楚。我们的目的是比较大小相符的LSL的长期结局，按其切除的e-EMR或p-EMR进行分层。方法分析了来自大型LSL的前瞻性三级转诊多中心队列中为期10年的EMR的数据。比较了通过p-EMR或e-EMR切除的大小匹配的LSL（20-25毫米）的结果。结果570个LSL符合纳入标准，其中e-EMR切除了259个（45.4％）。e-EMR组的严重深层壁壁损伤（DMI）风险显着更高（3.5％比1.0％，P = .05），而其他术中不良事件发生率没有显着差异。通过e-EMR切除的9例具有内镜特征的粘膜下浸润（SMI）的LSL中，有5例（56％）被手术切除。在e-EMR组中，初次监测的RRA较低（2.0％比5.7％，P = .04），但是在随后的监测中，这一差异被忽略了。在两个监测间隔中，两组之间的手术转诊率没有显着差异。结论当在大型前瞻性多中心队列中比较e-EMR与p-EMR病变大小小于或等于25 mm的相似形态时，e-EMR对预测的良性LSL没有其他优势。但是，它与主要DMI风险增加相关。因此，整块切除技术应保留用于可疑为浸润性疾病的病变。（临床试验注册号：