The SMART Trial: Modified Single-Stapled Anastomosis in Laparoscopic or Robotic Low Anterior Resection for Rectal Cancer

NCT07376980 | Enrolling By Invitation DMC

• 1 other identifier: 2025AN0114
• Study Type: interventional
• Target: 450
• Locations: 1 country
• Sites: 6

Brief Summary

The goal of this clinical trial is to learn whether a modified single-stapled anastomosis (MST) can reduce anastomotic leakage compared with the conventional double-stapled technique (DST) in adult patients undergoing laparoscopic or robotic low anterior resection for rectal cancer. The main questions it aims to answer are:

• Does MST lower the incidence of anastomotic leakage after rectal cancer surgery?
• Does MST improve short-term surgical outcomes compared with DST? Researchers will compare the MST group with the DST group to see if MST leads to fewer anastomotic leaks and safer postoperative recovery. Participants will: Receive either MST or DST during minimally invasive rectal cancer surgery Undergo routine postoperative CT scans within one month after surgery to check for symptomatic or asymptomatic anastomotic leakage Attend scheduled follow-up visits and standard postoperative assessments as part of routine rectal cancer care

Conditions

Rectal Cancer; Rectal Cancer Surgery; Rectal Neoplasms; Rectal Neoplasms Malignant

Keywords

Rectal Cancer; Total Mesorectal Excision; Low Anterior Resection; Anastomotic Leak; Anastomosis, Surgical; Stapled anastomosis; Modified Single-Stapled Technique; Minimally Invasive Rectal Surgery

Outcome Measures

Primary Outcomes (1)

• Anastomotic leakage

  Anastomotic leakage will be assessed within 30 days after surgery using clinical evaluation and routine abdominopelvic computed tomography (APCT). Leakage is defined as any defect in the anastomosis that results in communication between the inside of the bowel and the surrounding tissue. Diagnostic criteria include clinical symptoms (such as fever, abdominal pain, or drainage contents), abnormal laboratory findings, or radiologic evidence of leakage on APCT. All leaks will be classified according to the grading system. * Grade A: Leakage requiring no active therapeutic intervention. * Grade B: Leakage requiring non-surgical management, such as antibiotics or percutaneous drainage. * Grade C: Leakage requiring reoperation. Routine postoperative CT for all participants ensures consistent and standardized detection of both symptomatic and asymptomatic leaks.

  within 30 days after surgery

Study Arms (2)

Modified single-stapled anastomosis technique

EXPERIMENTAL

Participants assigned to this arm will undergo minimally invasive low anterior resection using the modified single-stapled technique. After rectal resection, the two ends of the linear staple line of stump are approximated toward the center using a barbed suture. The circular stapler spike is introduced through the center of the staple line to ensure complete resection of the linear staple line, eliminating staple-line intersections. The reaminder of the procedure, including total mesorectal excision, follows standard oncologic principles.

Procedure: Modified single-stapled anastomosis technique

Double-stapled anastomosis technique

NO INTERVENTION

Participants assigned to this arm will undergo minimally invasive low anterior resection using the conventional double-stapled technique. The rectum is transected with linear stapler, followed by transanal introduction of a circular stapler to create an end-to-end anastomosis. The procedure represents current standard practice for low anterior resection in rectal cancer.

Interventions

Modified single-stapled anastomosis technique PROCEDURE

This intervention applies a modified single-stapled anastomosis specifically to low anterior resection (LAR), where the technique has not been previously evaluated in a randomized controlled trial. Although similar concepts have been explored in anterior resection, their application in LAR is technically more challenging due to the deeper pelvic working space and more limited access to the rectal stump. In earlier studies, approximation of the linear staple line was performed through a Pfannelstein incision or mini-laparotomy incision during specimen extraction. In contrast, this trial utilizes a fully intracorporeal approach.

Also known as: Single-stapled anastomosis, Modified single-stapled anastomosis, Dog-ear-free anastomosis, Single-stapling technique, Modified double-stapling technique, Dog-ear closure technique

Modified single-stapled anastomosis technique

Eligibility Criteria

• Age: 19 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients with rectal cancer who are scheduled to undergo laparoscopic or robotic low anterior resection
• histologically confirmed rectal adenocarcinoma located within 15cm from anal verge.
• ECOG performance status of 0 to 2
• Any clinical stage

You may not qualify if:

• Who have significant comorbidities or history of abdominal surgeries that would preclude a minimally invasive approach
• Bowel obstruction for perforation requiring emergency surgey
• Concurrent, or recent treatment for colorectal or other malignancies within the past five years
• Presence of inflammatory bowel diseases
• Hereditary colorectal cancer syndrome

Sponsors & Collaborators

• Korea University Anam Hospital: lead
• Kyunghee University Medical Center: collaborator
• Seoul National University Hospital: collaborator
• Kyungpook National University Chilgok Hospital: collaborator
• Saint Vincent's Hospital, Korea: collaborator
• Sinchon Severance Hospital, Yonsei University College of Medicine: collaborator

Study Sites (6)

St. Vincent's Hospital

Suwon, Gyeonggi-do, 16247, South Korea

Location

Kyungpook National University Chilgok Hospital

Daegu, Gyeongsangbuk-do, 41404, South Korea

Location

Kyung Hee University Hospital

Seoul, 02447, South Korea

Location

Korea University Anam Hospital

Seoul, 02841, South Korea

Location

Seoul National University Hospital

Seoul, 03080, South Korea

Location

Severance Hospital

Seoul, 03722, South Korea

Location

MeSH Terms

Conditions

Rectal Neoplasms; Anastomotic Leak

Condition Hierarchy (Ancestors)

Colorectal Neoplasms; Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Diseases; Rectal Diseases; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Jin Kim, M.D., Ph.D

  Korea University Anam Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: No additional parties.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: This study uses a parallel assignment interventional model. Participants will be randomly allocated in a 1:1 ratio to one of two dependent surgical intervention arms: MST or DST. Each participatns will undergo only assigned surgical technique without crossover betwen groups.

Study Record Dates

• First Submitted: December 3, 2025
• First Posted: January 29, 2026
• Study Start: December 20, 2025
• Primary Completion (Estimated): December 30, 2027
• Study Completion (Estimated): December 30, 2030
• Last Updated: January 29, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

KR (6)