Safety & Efficacy of a Novel Asymmetrical Linear Stapler (NALS) for Securing Distal Resection Margin in Laparoscopic Rectal Cancer Surgery: Pilot Study

Current evidence indicates distal margins of greater than 1cm from the tumor is necessary for superior oncologic outcomes. In middle to lower rectal cancer, where the tumor is close to the anus, sparing the anus whilst securing such a margin may prove difficult.

Failure to secure sufficient margin length may end up in cancer recurrence, but inaccurate assessment of the margin status may also cause further unnecessary resection or failure to spare the anus.

The novel asymmetrical linear stapler was designed specifically with this problem in mind, and one row of stapling was removed from the specimen side to allow easier harvesting of a undisrupted distal margin tissue for pathological evaluation.

This study is a pilot RCT of 30 patients each in the novel stapler group and control group, to prove the non-inferiority in safety and superiority in harvesting the distal margin (assessed by length of margin and time to harvest).

• Novel asymmetrical linear stapler (Device): Novel asymmetrical linear stapler
• Signia™ (Device): Signia™

Primary outcomes

• True distal margin length > 1cm [Intraoperative]: True distal margin: The length of tissue from the distal edge of the specimen to the distal tumor margin in the surgical specimen

Secondary outcomes

• Early anastomosis leakage [From randomization until the date of first documented sign of leakage, assessed up to 30 days]: Anastomosis leakage within 30 days of surgery will be documented and reported as an outcome. The International Study Group of Rectal Cancer definition of anastomosis leakage will be used to define the outcome (defect of the intestinal wall at the anastomotic site leading to a communication between the intra- and extraluminal compartments, requiring NPO or other intervention). Patients that have clinical signs of infection (fever, sepsis, inflammatory lab change or abdominal drain color change) with either fluid collection near the anastomosis or an anastomosis defect on CT imaging will be diagnosed as having anastomosis leakage. CT scans will not be taken routinely, but will be performed when signs of infection (such as abdominal tenderness or high fever) are present. Severity of the anastomosis leak will be graded according to the International Study Group of Rectal Cancer grading system (grade A, B, C) depending on the necessary intervention (none, non-surgical or surgical).
• Time to harvest margin [Intraoperative (from the beginning of frozen section specimen harvest until the acquirement is completed. This process will be timed by a member of the surgical team using a timer.)]: Time (seconds) taken to harvest the distal margin from the specimen for frozen section biopsy
• Specimen integrity [Intraoperative (at the time point of the frozen section pathology report)]: The pathologist evaluation of whether the whole thickness of bowel was harvested in the distal margin frozen section biopsy. This will be requested and reviewed, reported in the final pathologist report.
• Sphincter preservation rate [From randomization until the end of clinical data collection, assessed up to 120 days.]: Although all eligible candidates will be planned for sphincter-preserving surgery, there are some cases where the distal margin is not suffice for an R0 resection and thus receive non-sphincter preserving surgery. The incidence of such non-sphincter preserving surgery (example: abdominoperineal resection) will be reported.

Sex: All, ages: 19 Years to 79 Years

Inclusion Criteria:

* Rectal cancer patients between the age of 19\~79, who require anus preserving laparoscopic rectum resection surgery

Exclusion Criteria:

* Advanced rectal cancer that invades surrounding structures or has known distant metastasis
* Uncontrolled comorbidities
* Patients otherwise considered unsuitable for the study