BACKGROUND AND AIMS: It is believed that preoperative biopsy sampling for superficial-type colorectal tumors should be avoided because submucosal fibrosis caused by biopsy sampling makes EMR impossible. However, few studies have reported the influence of biopsy sampling on colorectal endoscopic submucosal dissection (ESD). This study aimed to examine the effect of biopsy sampling on submucosal fibrosis and treatment outcomes of ESD for laterally spreading tumors (LSTs). METHODS: Between April 2005 and September 2015, 441 consecutive patients underwent colorectal ESD in Osaka City University Hospital. Using propensity score matching and inverse probability of treatment weighting (IPTW), we retrospectively evaluated risk factors for severe submucosal fibrosis and treatment outcomes for patients with LSTs, with or without preoperative biopsy sampling. RESULTS: A total of 428 LSTs resected using ESD were enrolled. After matching, there were 136 matched pairs of lesions that did or did not undergo biopsy sampling. Preoperative biopsy sampling increased severe fibrosis compared with that in the non-biopsy sampling group (20.6% vs 11.0%; P = .03) and was significantly associated with severe fibrosis after matching (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.07-4.10; P = .03). After adjustment with IPTW, biopsy sampling also increased the risk of severe fibrosis (OR, 2.33; 95% CI, 1.17-4.63; P = .02). However, no significant differences were observed between the 2 groups in treatment outcomes. CONCLUSIONS: Preoperative biopsy sampling for colorectal LSTs might cause severe submucosal fibrosis but has no adverse influence on clinical outcomes of ESD.
BACKGROUND AND AIMS: It is believed that preoperative biopsy sampling for superficial-type colorectal tumors should be avoided because submucosal fibrosis caused by biopsy sampling makes EMR impossible. However, few studies have reported the influence of biopsy sampling on colorectal endoscopic submucosal dissection (ESD). This study aimed to examine the effect of biopsy sampling on submucosal fibrosis and treatment outcomes of ESD for laterally spreading tumors (LSTs). METHODS: Between April 2005 and September 2015, 441 consecutive patients underwent colorectal ESD in Osaka City University Hospital. Using propensity score matching and inverse probability of treatment weighting (IPTW), we retrospectively evaluated risk factors for severe submucosal fibrosis and treatment outcomes for patients with LSTs, with or without preoperative biopsy sampling. RESULTS: A total of 428 LSTs resected using ESD were enrolled. After matching, there were 136 matched pairs of lesions that did or did not undergo biopsy sampling. Preoperative biopsy sampling increased severe fibrosis compared with that in the non-biopsy sampling group (20.6% vs 11.0%; P = .03) and was significantly associated with severe fibrosis after matching (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.07-4.10; P = .03). After adjustment with IPTW, biopsy sampling also increased the risk of severe fibrosis (OR, 2.33; 95% CI, 1.17-4.63; P = .02). However, no significant differences were observed between the 2 groups in treatment outcomes. CONCLUSIONS: Preoperative biopsy sampling for colorectal LSTs might cause severe submucosal fibrosis but has no adverse influence on clinical outcomes of ESD.