Warm Saline Irrigation Before Omentopexy to Reduce Early Bleeding After Laparoscopic Sleeve Gastrectomy (WARM-LSG)

Ain Shams University

Status: Completed

Conditions: Postoperative Hemorrhage; Obesity

Treatments: Procedure: Room Temperature Saline Irrigation; Procedure: Warm Saline Irrigation

Study type: Interventional

Funder types: Other

Identifiers

NCT07475169

FMASU-REC-49/2024

Details and patient eligibility

About

This prospective randomized clinical trial evaluates whether warming saline irrigation (37-40 °C) applied to the gastric staple line before performing omentopexy during laparoscopic sleeve gastrectomy (LSG) can reduce early postoperative bleeding compared with conventional room-temperature saline irrigation.

Staple-line bleeding remains one of the most relevant early complications after LSG and may lead to hemoglobin drop, prolonged drainage, blood transfusion, or re-intervention. Although reinforcement techniques such as oversewing or buttressing materials are commonly used, they may increase operative time and cost. Irrigation of the operative field is routinely performed during LSG to improve visualization; however, the potential effect of irrigation temperature on hemostasis has not been previously evaluated in bariatric surgery.

In this trial, 200 adult patients undergoing primary LSG were randomized in a 1:1 ratio to receive either warm saline irrigation (37-40 °C) or standard room-temperature saline irrigation (22-24 °C) applied directly to the staple line before omentopexy. All other operative steps were standardized.

The primary outcome is early postoperative bleeding within 48 hours. Secondary outcomes include hemoglobin drop, drain output, need for additional hemostatic maneuvers, operative efficiency, postoperative pain, length of hospital stay, and 30-day complications.

This study investigates a simple, low-cost, and easily applicable intraoperative modification that may enhance staple-line hemostasis and improve early recovery following LSG.

Full description

Study Design and Rationale:

This study is a prospective, randomized, controlled clinical trial conducted at two high-volume tertiary bariatric centers. The aim is to evaluate whether irrigation of the gastric staple line with physiologically warm saline (37-40 °C) before performing omentopexy improves intraoperative hemostasis and reduces early postoperative bleeding following laparoscopic sleeve gastrectomy (LSG).

Irrigation of the operative field is standard practice during laparoscopic surgery to clear blood and enhance visualization. However, the effect of irrigation temperature on staple-line hemostasis in bariatric surgery has not been previously studied. Warm irrigation has demonstrated hemostatic and recovery benefits in other surgical specialties. This trial compares two clinically relevant strategies: warm saline versus conventional room-temperature saline.

Participants:

A total of 200 adult patients (18-60 years) undergoing primary LSG were enrolled. Inclusion criteria included BMI ≥ 40 kg/m² or ≥ 35 kg/m² with obesity-related comorbidities. Patients with coagulopathy, recent anticoagulant use, prior major upper abdominal surgery, advanced organ failure, pregnancy, or inability to complete follow-up were excluded.

Randomization and Allocation:

Patients were randomized in a 1:1 ratio using a computer-generated sequence with allocation concealment via sealed opaque envelopes. Surgeons were aware of the irrigation temperature, while postoperative assessors and patients were blinded to group allocation.

Intervention:

After completion of gastric transection using a 36-French bougie calibration, patients received:

• Warm Irrigation Group: 400 mL sterile saline at 37-40 °C applied along the staple line.
• Control Group: 400 mL sterile saline at 22-24 °C applied identically.

After irrigation and complete suctioning, the staple line was inspected and any active bleeding was controlled using bipolar cautery or clips. Standardized omentopexy was then performed in all patients using interrupted 2-0 PDS sutures spaced 2 cm apart.

No buttressing material, sealants, or additional reinforcement techniques were used in either group.

Primary Outcome:

Early postoperative bleeding within 48 hours, defined as any of the following:

• Hemoglobin drop ≥ 2 g/dL
• Drain output ≥ 150 mL sanguineous fluid within 24 hours
• Clinical signs of bleeding
• Need for endoscopic or surgical hemostasis

Secondary Outcomes:

• Hemostasis-phase duration
• Hemoglobin drop (continuous variable)
• 24-hour drain output
• Additional intraoperative hemostatic maneuvers
• Postoperative pain scores
• Postoperative nausea and vomiting
• Length of hospital stay
• 30-day complications (Clavien-Dindo classification)
• Reoperation or readmission

Follow-up:

Patients were evaluated during hospitalization and followed at 1 week, 1 month, and 3 months postoperatively. All randomized patients completed follow-up and were included in intention-to-treat analysis.

Statistical Considerations:

Sample size was calculated to detect reduction in bleeding incidence from 15% to 5% with 80% power. Statistical significance was defined as p < 0.05.

This study evaluates a safe, inexpensive, and easily reproducible intraoperative modification that may improve staple-line hemostasis and early recovery after LSG.

Enrollment: 200 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age between 18 and 60 years
• BMI ≥ 40 kg/m², or BMI ≥ 35 kg/m² with at least one obesity-related comorbidity (e.g., type 2 diabetes, hypertension, obstructive sleep apnea)
• Eligible for primary laparoscopic sleeve gastrectomy
• Provided written informed consent

Exclusion criteria

• Previous major upper abdominal surgery with expected adhesions
• Known bleeding disorders
• Use of anticoagulant or antiplatelet therapy within 7 days before surgery
• Advanced hepatic or renal disease
• Unstable cardiac conditions
• Pregnancy
• Immunosuppression
• Active systemic infection
• Inability to comply with follow-up schedule

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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200 participants in 2 patient groups

Warm Saline Irrigation

Experimental group

Description:

Warm saline irrigation (37-40°C) applied to the gastric staple line before omentopexy during laparoscopic sleeve gastrectomy.

Treatment:

Procedure: Warm Saline Irrigation

Room Temperature Saline

Active Comparator group

Description:

Standard room-temperature saline irrigation applied to the gastric staple line before omentopexy.

Treatment:

Procedure: Room Temperature Saline Irrigation