Indiana University School of Medicine Fort Wayne, Indiana
Introduction: The advantages of endoscopic submucosal dissection (ESD) over endoscopic mucosal resection for large sessile and laterally spreading colorectal neoplasms are well established, most notably, high R0 and en bloc resection rates, and potential cure of intramucosal neoplasms. Increased frequency of adverse events, technical challenges, and lack of adequate training in ESD limit its widespread adoption in the western world.
Methods: A comprehensive literature search was performed in electronic databases in May 2021 for published manuscripts and abstracts of studies performed in non-Asian countries (Europe, Americas, or Australia) that evaluated the effectiveness of ESD for colorectal neoplasms. Pooled (weighted) rates of en bloc and R0 resection rates, perforation, and lower gastrointestinal bleeding were obtained using random-effects model. The study is registered in PROSPERO (CRD42021247492).
Results: Thirty-two studies (30 retrospective and two prospective) comprising 3,295 patients met the inclusion criteria (table 1). 96.7% (2,817/2913) of polyps were ≥2 cm. Twenty-five studies were conducted in European countries, three in the United States, one in Brazil and three studies were multinational. Pooled en bloc resection rate (27 studies) was 86% (95% CI 0.82-0.90%) and R0 resection rate (28 studies) was 76% (95% CI 0.70-0.81) (figures 1a-c). Procedure-related perforation rate was (24 studies) was 5.2% (95% CI 0.04-0.07) and clinically significant bleeding (23 studies) was observed in 4.6% (95% CI 0.036-0.058). Surgery for invasive cancer (21 studies) was performed in 4.3% (95% CI 0.029-0.064) of patients. There was a high degree of heterogeneity for en bloc resection (I2 85%), R0 resection (I2 91%), perforation (I2 59%), and surgery for invasive cancer (I2 67%), and low heterogeneity was observed for bleeding (I2 24%).
Discussion: En bloc and R0 resection rates of ESD for large colorectal polyps are acceptable in Western countries. Both these rates have improved compared to previous reports from non-Asian countries.(1) Bowel perforation and clinically significant bleeding are still observed in 5-10% of ESD procedures. Ongoing efforts to train therapeutic endoscopists will probably improve the safety and effectiveness of colorectal ESD in the West.
References 1. Fuccio L, Hassan C, Ponchon T, et al. Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis. Gastrointestinal Endoscopy 2017;86:74-86.e17.
