Clinical trial NCT06982664: Effect of Preserving the Left Colic Artery on Proximal Bowel Perfusion
Official title: Effect of Preserving the Left Colic Artery on Proximal Bowel and Anastomotic Blood Perfusion During Radical Resection for Rectal Cancer: A Randomized Controlled Trial Based on Laser Speckle Contrast Imaging
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Rectal Cancer Surgery
Perfusion Imaging
Anastomosis, Leaking
Keywords: rectal caner
Perfusion
Anastomosis leakage
Laser Speckle Contrast Imaging
Lead sponsor: Ningbo Medical Center Lihuili Hospital
Sponsor class: OTHER_GOV
First posted: 2025-05-21
Enrollment: 143
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Patients were categorized into two groups, HT and LT, based on the planned management of the IMA.

HT Group: In the HT group, the IMA was ligated approximately 1 cm from its origin after meticulous dissection of the surrounding tissue to ensure clear visualization of the IMA root.

LT Group: In the LT group, the surgical approach focused on preserving the LCA. Apical lymph node dissection was performed around the origin of the IMA. The superior rectal artery was ligated distal to the origin of the LCA.

As part of the prospective cohort sub-study in the LT group, the preserved LCA underwent temporary, controlled occlusion intraoperatively. This was done after confirming LCA preservation and before colonic transection or anastomosis. The aim was to assess perfusion changes-such as retraction of the ischemic demarcation line using LSCI-to evaluate the functional role of the LCA. After assessment, the occlusion was released to restore blood flow.
Primary purpose: TREATMENT

Brief summary: Patients with rectal or rectosigmoid cancer undergoing radical resection will be randomly assigned to either high-tie (HT) or low-tie (LT) ligation of the Inferior Mesenteric Artery (IMA). Proximal bowel blood perfusion will be measured using Laser Speckle Contrast Imaging, and the perfusion characteristics will be compared between the two ligation groups.

Additionally, for participants randomized to the LT group, an embedded prospective cohort sub-study will be performed. This sub-study involves controlled, temporary intraoperative occlusion of the preserved Left Colic Artery (LCA). During this temporary occlusion, LSCI will be used to assess the resulting changes in colonic perfusion, specifically measuring outcomes like the ischemic demarcation line (LOD) retraction distance, to further investigate the functional contribution of the preserved LCA. The overall trial aims to determine the optimal IMA ligation strategy based on objective perfusion data and a deeper understanding of LCA's role.

Detailed description: The primary goal of this clinical trial is to compare proximal bowel blood perfusion following HT versus LT of the IMA during anterior resection for rectal cancer. LSCI will be used to assess perfusion in both groups.Additionally, this trial incorporates an embedded prospective cohort sub-study, which will be conducted specifically within the LT group, where the Left Colic Artery (LCA) is preserved. The purpose of this sub-study is to further elucidate the impact of this LCA preservation on left colonic perfusion in these patients. This will be achieved by investigating the retraction distance of the ischemic demarcation line following temporary occlusion of the preserved LCA under LSCI guidance, and by exploring potential anatomical and pathophysiological factors that may contribute to variations in this retraction distance.

The main questions the study seeks to answer are:

Does HT ligation result in significantly different proximal bowel blood perfusion, as measured by LSCI, compared to LT ligation? Does knowledge of intraoperative bowel perfusion, as assessed by LSCI, influence surgical decision-making, specifically regarding changes to the planned transection line? Are there significant differences in quantified perfusion intensity at the transection line between HT and LT ligation techniques? What is the retraction distance of the ischemic demarcation line, observed via LSCI, following temporary occlusion of the LCA, and what are the potential anatomical or pathophysiological factors associated with variations in this distance? Patients undergoing anterior resection for rectal cancer will be randomized to receive either HT or LT ligation of the IMA. LSCI will be used intraoperatively to assess bowel perfusion.

Participants will:

Undergo anterior resection for either rectal or rectosigmoid cancer, with HT or LT ligation of the IMA determined by the randomization process.

Have bowel perfusion assessed intraoperatively using LSCI. Have the maximum perfusion distance (MPD) measured as the primary outcome for the main randomized trial component.

Have the perfusion intensity at the transection line quantified as a secondary outcome.

Have any changes to the planned transection line documented based on intraoperative LSCI findings, as a secondary outcome.

As part of the embedded prospective cohort sub-study, undergo temporary intraoperative occlusion of the LCA with subsequent LSCI assessment to measure the retraction distance of the ischemic demarcation line.

As part of the embedded prospective cohort sub-study, have data collected on relevant potential anatomical (e.g., vascular anatomy variations) and pathophysiological factors (e.g., presence of atherosclerosis, patient comorbidities) that may influence the ischemic demarcation line retraction distance.

This trial aims to provide high-level evidence to inform and optimize IMA management strategies during anterior resection for rectal or rectosigmoid cancer, based on proximal bowel perfusion assessment using LSCI visualization, and to provide deeper mechanistic insights into the specific role and functional importance of the LCA in maintaining colonic perfusion.

Eligibility criteria: Inclusion Criteria:

1. a confirmed diagnosis based on pathological reports;
2. patients who had not received any prior treatment;

Exclusion Criteria:

1. a history of previous abdominal surgery or neoadjuvant chemotherapy/radiation affecting bowel perfusion or anastomosis;
2. patients requiring emergency surgery due to acute complications;
3. intraoperative findings necessitating a shift to alternative procedures, such as local excision, abdominoperineal resection, Hartmann's operation, or intersphincteric resection.

Primary outcomes:
measure: Maximum Perfusion Distance (MPD)
timeFrame: Perioperative
Secondary outcomes:
measure: Number of participants requiring revision of the planned bowel transection line following intraoperative Laser Speckle Contrast Imaging (LSCI)-based bowel perfusion assessment
timeFrame: Perioperative
measure: Speckle Flow Index (SFI) at the Proximal Anastomosis Site Measured by Laser Speckle Contrast Imaging (LSCI)
timeFrame: Perioperative
measure: Ischemic Demarcation Line (LOD) Retraction Distance
timeFrame: Perioperative
Other outcomes:
measure: Intraoperative blood loss
timeFrame: Perioperative
measure: Operative time
timeFrame: Perioperative
measure: Intraoperative blood transfusion
timeFrame: Perioperative
measure: Postoperative surgical complications
timeFrame: Perioperative
measure: Anastomotic leakage rate
timeFrame: Perioperative
measure: Length of hospital stay
timeFrame: Perioperative
Locations:
Study officials:
affiliation: Ningbo Medical Center of Lihuili Hospital
name: Jiazi Yu, M.D.
role: STUDY_DIRECTOR
References: