Single-Stapled Technique for Colorectal Anastomosis (SST)

Single-Stapled Technique for Colorectal Anastomosis After Left-Sided Colectomy, Sigmoid Resection or Partial Mesorectal Excision: A Multicentre Prospective Observational Cohort Study

The goal of this observational multicenter study is to evaluate the safety and feasibility of a single-stapled technique (SST) for colorectal anastomosis and to explore whether this technique is associated with a reduced rate of anastomotic leakage compared with the conventional double-stapled technique (DST).

The study includes adult patients undergoing planned left-sided colorectal resection with colorectal anastomosis, including sigmoid resection, left hemicolectomy, or partial mesorectal excision (PME), for benign or malignant disease.

The main questions it aims to answer are:

What is the rate of anastomotic leakage within 90 days after surgery in patients operated with the single-stapled technique?

Is the single-stapled technique feasible and safe across different surgical approaches (open, laparoscopic, and robot-assisted surgery) in a multicenter setting?

Furthermore, outcomes after single-stapled anastomosis will be compared with a retrospective cohort of patients operated with the conventional double-stapled technique to explore potential differences in anastomotic leakage rates and postoperative complications.

Participants will receive standard surgical care as determined by the treating surgical team. Patients included in the prospective part of the study will undergo colorectal anastomosis using the single-stapled technique as part of routine clinical practice. Data on perioperative variables, postoperative complications (including anastomotic leakage graded according to international consensus definitions), and follow-up outcomes will be collected prospectively using an electronic case report form (eCRF). A retrospective cohort from the same participating centers will be identified through medical record review using identical inclusion criteria.

The results of this study are intended to provide robust multicenter data on the safety and clinical outcomes of the single-stapled technique and to serve as the basis for planning a future randomized controlled multicenter trial.

Study Overview

• Status: Recruiting
• Conditions: Colorectal Cancer; Diverticular Disease of Left Side of Colon; Anastomotic Leakage; Colorectal Anastomosis
• Intervention / Treatment: Procedure: Single-stapled colorectal anastomosis; Procedure: Double-stapled colorectal anastomosis

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Oskar Grahn, MD, PhD; Phone Number: +46907850000; Email: oskar.grahn@umu.se

Study Locations

• Sweden
  • Gothenburg, Sweden
    • Recruiting
    • Östra Sahlgrenska University Hospital
    • Contact: Martin Rutegård, MD, PhD; Phone Number: +4631 342 10 00; Email: martin.rutegard@vgregion.se
  • Luleå, Sweden
    • Recruiting
    • Sunderby Hospital
    • Contact: Christoffer Odensten, MD, PhD; Phone Number: +46920 28 20 00; Email: christoffer.odensten@umu.se
  • Malmo, Sweden
    • Recruiting
    • Skåne University Hospital
    • Contact: Erik Agger, MD, PhD; Phone Number: +4640 33 10 00
  • Umeå, Sweden
    • Recruiting
    • Surgical Centre, Umeå University Hospital
    • Contact: Oskar Grahn, MD, PhD; Phone Number: +46907850000; Email: oskar.grahn@umu.se
  • Uppsala, Sweden
    • Recruiting
    • Uppsala University Hospital
    • Contact: Malin Enblad, MD, PhD; Phone Number: +4618 611 00 00; Email: malin.enblad@uu.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients (≥18 years) undergoing planned left-sided colorectal resection with construction of a colorectal anastomosis, including left hemicolectomy, sigmoid resection, or partial mesorectal excision, for benign or malignant indications.

Patients are treated as part of routine clinical care at participating centers. The study includes both a retrospective cohort of patients operated during 2023-2025 and a prospective cohort of consecutively included patients undergoing surgery after study initiation. In the prospective cohort, the intent is to perform a single-stapled colorectal anastomosis when technically feasible in all consenting patients.

Description

Inclusion Criteria:

• Age ≥ 18 years.
• Planned (elective) left-sided colorectal resection with creation of a colorectal anastomosis, including: Left hemicolectomy, and/or Sigmoid resection, and/or Partial mesorectal excision (PME).
• Benign or malignant indication.
• Prospective cohort: Ability to provide written informed consent.
• Retrospective cohort: Eligible patients operated during 2023-2025 at participating centers, identified through medical record review, meeting the same surgical inclusion criteria.

Exclusion Criteria:

• Total mesorectal excision (TME) (e.g., low rectal cancer surgery requiring TME).
• Non-left-sided colorectal resections (e.g., right-sided colectomy) or procedures outside the study-defined operations.
• Surgery not involving a colorectal anastomosis (e.g., end colostomy/Hartmann's procedure without anastomosis).
• Emergency/urgent colorectal resection (non-elective surgery).
• Prospective cohort: Inability to provide informed consent.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Prospective single-stapled technique cohort; Adult patients undergoing planned left-sided colorectal resection with colorectal anastomosis (including sigmoid resection, left hemicolectomy, or partial mesorectal excision) in whom the anastomosis is constructed using the single-stapled technique (SST) as part of routine clinical practice. Patients are included prospectively and followed for postoperative complications, including anastomotic leakage within 90 days, as well as longer-term outcomes.	Procedure: Single-stapled colorectal anastomosis; Construction of a colorectal anastomosis using a single-stapled technique, where the rectal staple line is excised and a purse-string suture is placed on the rectal stump and tied around the tip of a circular stapler, before completion of the anastomosis. The procedure is performed as part of routine clinical practice during planned left-sided colorectal resection.
Retrospective double-stapled technique cohort; A retrospective cohort of adult patients who previously underwent planned left-sided colorectal resection with colorectal anastomosis using the conventional double-stapled technique (DST) during the years 2023-2025. Patients are identified through medical record review at participating centers using the same inclusion criteria as the prospective cohort, and outcome data are collected retrospectively for comparison.	Procedure: Double-stapled colorectal anastomosis; Construction of a colorectal anastomosis using the conventional double-stapled technique, where the rectal stump is closed with a linear stapler and the anastomosis is completed using a circular stapler and without excision of the rectal staple line. The procedure is performed as part of standard surgical practice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anastomotic leakage (ISREC), within 90 days	Anastomotic leakage following colorectal anastomosis, defined according to the International Study Group of Rectal Cancer (ISREC). Anastomotic leakage is recorded as a binary outcome (yes/no). Severity grading (ISREC Grade A, B, or C) will be reported descriptively as part of the same outcome.	Within 90 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of the single-stapled technique (SST)	Feasibility defined as the proportion of intended SST cases in which the colorectal anastomosis could be completed using the single-stapled technique as planned, without intraoperative conversion to another anastomotic technique.	During surgery
Completeness of stapled anastomotic rings	Binary intraoperative assessment of stapled anastomotic ring completeness, recorded as complete or incomplete.	During surgery
Intraoperative air leak test result	Binary intraoperative air leak test result, recorded as leak detected or no leak detected.	During surgery
Duration of surgery	Total operative time measured in minutes from skin incision to skin closure.	During surgery
Length of postoperative hospital stay	Length of hospital stay measured in days from the date of surgery to the date of discharge.	Within 90 days of primary surgery
Hospital readmission rate	Proportion of patients readmitted to hospital within 90 days after surgery, with causes recorded descriptively.	Within 90 days after surgery
Postoperative complications (Clavien-Dindo classification)	Highest Clavien-Dindo grade within 90 days after surgery (Grade I-V), where higher grade indicates more severe complications.	Within 90 days after surgery
All-cause mortality	Proportion of patients who die from any cause within 90 days after surgery.	Within 90 days after surgery
Recurrence-free survival	Recurrence-free survival defined as time from surgery to the first occurrence of local recurrence, distant recurrence, or death from any cause.	Upto three years after primary surgery
Stoma-free survival	Stoma-free survival defined as survival without a diverting or permanent stoma following left-sided colorectal surgery.	At one and three years after surgery

Collaborators and Investigators

• Sponsor: Umeå University
• Collaborators: Skane University Hospital; Sahlgrenska University Hospital
• Investigators: Principal Investigator: Oskar Grahn, MD, PhD, Umea University / Region Vasterbotten; Principal Investigator: Martin Rutegård, MD, PhD, Ostra Sahlgrenska University Hospital, Gothenburg, Sweden

Study record dates

Study Major Dates

• Study Start (Actual): January 7, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): June 30, 2029

Study Registration Dates

• First Submitted: January 27, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 10, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Colorectal surgery; Anastomotic leakage; Colorectal anastomosis; Single-stapled anastomosis; Left-sided colon resection; Partial mesorectal excision
• Additional Relevant MeSH Terms: Postoperative Complications; Pathologic Processes; Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Colonic Diseases; Pathological Conditions, Signs and Symptoms; Colorectal Neoplasms; Anastomotic Leak
• Other Study ID Numbers: SST-MC-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No