Curative Effect Analysis of Endoscopic Submucosal Dissection in Giant Laterally Spreading Rectal Tumors

Goal: The objective of this study was to investigate the clinical efficacy of endoscopic submucosal dissection (ESD) in the treatment of giant lateral developing rectal-type tumors (laterally spreading tumors, LSTs). Background: There are no specialized studies on the efficacy of ESD in the treatment of LSTs measuring >5 cm in diameter, surgery was often used in the past, but it has the disadvantages of large trauma, many complications, and high cost. Methods: The data of 185 patients with rectal LSTs who had undergone ESD in the digestive endoscopy center of our hospital from January 2012 to June 2020 were retrospectively analyzed. Based on the size of the lesions, the patients were divided into 2 groups: diameter <= 5 cm (110 cases) and diameter >5 cm (75 cases), and we summarized and analyzed the en bloc resection rate, curative resection rate, procedure time, muscle injury, bleeding, perforation, postoperative stricture, and recurrence. Results: There was no difference in the en bloc resection rate and R0 resection rate between the 2 groups (P=0.531). Moreover, there was no difference in the incidence of delayed perforation, postoperative stenosis, and recurrence, but the incidence of delayed bleeding was significantly higher in the giant LST group than the small LST group (P=0.001). Moreover, for giant rectal LSTs, the growth pattern of the lesion, JNET classification, and the extent of postoperative mucosal defect do not significantly affect the efficacy of ESD. It is worth mentioning that the operation time was longer in the group with a diameter >5 cm, in which perforation was more frequent and the muscle layer was more likely to be injured during ESD (P<0.001). The muscle injury during ESD was mainly related to the diameter of the lesion, the crossing the rectal pouch, and the operation time. Conclusions: The use of ESD to treat giant rectal LSTs (>5 cm) is relatively difficult and can easily lead to intraoperative muscle injury, perforation, and late postoperative bleeding. However, if active intervention is performed, patients can still achieve good efficacy and prognosis, which can be applied in hospitals with certain conditions.