Efficacy and Safety of Robot-assisted Endoscopic Submucosal Dissection for Colorectal Neoplasm

• FASTER-assisted ESD (Procedure): The patients who are randomly assigned to the FASTER-assisted ESD group will undergo the ESD procedure with the assistance of the FASTER system.
• Conventional ESD (Procedure): The patients who are randomly assigned to the conventional ESD group will undergo the ESD following the clinically established pattern.

Primary outcomes

• procedure time [Within 24 hours after the procedure.]: Procedure time is the time from the beginning of injection to the completion of dissection.

Secondary outcomes

• dissection time [Within 24 hours after the procedure.]: Dissection time is the time from the beginning of dissection to the completion of dissection.
• dissection speed [Within 24 hours after the procedure.]: Dissection speed is defined as the lesion area divided by the dissection time.
• en bloc resection rate [Within 24 hours after the procedure.]: En bloc dissection refers to the complete removal of the entire lesion in a single piece.
• R0 resection rate [Within 24 hours after the procedure.]: R0 resection is defined as en bloc resection with negative vertical and horizontal margins.
• perforation rate [Within 24 hours after the procedure.]: Perforation were defined as: endoscopic visualization of mural transection during ESD, or postoperative clinical signs combined with radiologically confirmed pneumoperitoneum.
• postoperative hemorrhage rate [Within 24 hours after the procedure.]: Post-ESD hemorrhage was strictly defined as meeting ≥1 of: hematemesis or melena with dizziness, hemoglobin decline >20 g/L, SBP drop >20 mmHg or HR elevation >20 bpm, presence of bloody fluid in nasogastric tube drainage, or active bleeding confirmed by repeat endoscopy.
• intraoperative hemorrhage rate [Within 24 hours after the procedure.]
• the proportion of intraoperative hemorrhage ≥ grade 2 [Within 24 hours after the procedure.]: Intraoperative hemorrhage is divided into four grades: Grade 0 means no significant bleeding is observed during the procedure. Grade 1 means minimal bleeding, which could stop spontaneously or be easily controlled by cauterization with a dual knife. Grade 2 refers to minor hemorrhage that requires multiple cauterizations with a dual knife or hemostatic forceps. Grade 3 indicates massive hemorrhage that requires multiple cauterizations with hemostatic forceps.
• hemostasis time [Within 24 hours after the procedure.]: Hemostasis time referred to the time from the detection of submucosal bleeding until hemostasis was completed.
• muscular injury rate [Within 24 hours after the procedure.]: Muscular injury is described as visible damage to the muscularis propria.
• direct-vision dissection rate [Within 24 hours after the procedure.]: Direct-vision dissection time is the time that the endoscopist can directly observe the tip of the dual knife and the submucosal layer at the same time. By dividing the direct-vision dissection time by the total dissection duration, the direct-vision dissection rate is calculated.
• postoperative pain score [3 days after the procedure.]: Postoperative pain score was assessed via the 11-point Numerical Rating Scale (NRS: 0=no pain, 10=worst imaginable pain). Patients independently rated their pain intensity on postoperative day 3, with scores categorized as mild (1-3), moderate (4-6), or severe (7-10).*
• the frequency of supplemental injections [Within 24 hours after the procedure.]: Supplemental injection refers to injections performed after the beginning of the dissection.
• the supplemental injections time [Within 24 hours after the procedure.]: The time of supplementary injection is from the insertion of the injection needle into the submucosal layer until the injection is completed and the needle is withdrawn.
• Volume of injection fluid used in supplemental injections [Within 24 hours after the procedure.]
• the frequency of intraoperative patient positioning changes [Within 24 hours after the procedure.]
• time required for patient positioning changes [Within 24 hours after the procedure.]
• NASA-TLX scale scores [Within 24 hours after the procedure.]

Sex: All, ages: 18 Years to 85 Years

Inclusion Criteria:

* Patients aged 18-85.
* Patients with pathologically verified colorectal neoplasms scheduled to undergo ESD.

Exclusion Criteria:

* Patients have lesions with confirmed or potential deep submucosal invasion or lymph node metastasis or other conditions that are not suitable for endoscopic therapy.
* Patients with severe underlying diseases precluding endotracheal intubation, general anesthesia, or surgery.
* Patients have a history of colorectal malignancy with previous radiotherapy or operative treatment leading to changes in colorectal structure.
* Patients have lesions with local recurrence after endoscopic resection.
* Patients unable to obtain informed consent.