Intertransverse Process Block Versus External Oblique Intercostal Plane Block After Laparoscopic Sleeve Gastrectomy

Intertransverse Process Block Versus External Oblique Intercostal Plane Block for Postoperative Analgesia After Laparoscopic Sleeve Gastrectomy: A Prospective Randomized Controlled Trial

This randomized clinical trial aims to evaluate and compare the analgesic efficacy of the Intertransverse Process Block (ITPB) and the Subcostal External Oblique Intercostal Plane Block (EOIPB) in patients undergoing laparoscopic sleeve gastrectomy. The primary outcome is the Visual Analog Scale (VAS) score within the first 24 hours after surgery. Secondary outcomes include total opioid consumption, requirement for rescue analgesia, block-related complications and adverse effects (hematoma, pneumothorax, local anesthetic systemic complications, vascular puncture, and infection), patient satisfaction assessed using a Likert scale, quality of recovery assessed using the QoR-15 questionnaire, and incidence of postoperative nausea and vomiting.

Study Overview

• Status: Not yet recruiting
• Conditions: Postoperative Pain; Regional Anaesthesia; Sleeve Gastrectomy; Intertransverse Process Block; External Oblique Intercostal Plane Block
• Intervention / Treatment: Procedure: Intertransverse Process Block; Procedure: External Oblique Intercostal Plane Block

Detailed Description

Study Objective: This research aims to obtain objective data to demonstrate the effectiveness of two regional block techniques in acute pain management. The primary objective is to compare the effects of Intertransverse Process Block (ITPB) and Subcostal External Oblique Intercostal Plane Block (EOIPB) on Visual Analog Scale (VAS) scores in patients undergoing laparoscopic sleeve gastrectomy. Secondary outcomes include evaluating the impact of these blocks on total opioid consumption within the first 24 hours, requirement for rescue analgesia, block-related and systemic complications (hematoma, pneumothorax, local anesthetic systemic toxicity, vascular puncture, infection), patient satisfaction assessed using a Likert scale, quality of recovery assessed using the QoR-15 questionnaire, and incidence of postoperative nausea and vomiting.

Materials and Methods: This prospective, randomized clinical study will include voluntary patients aged 18-65 years, classified as American Society of Anesthesiologists (ASA) physical status I-III, with a body mass index (BMI) >35 kg/m². All participants will be informed about the study protocol in detail, and written informed consent will be obtained prior to inclusion. Patients will receive instruction on the use of the VAS for pain assessment, where 0 denotes no pain and 10 denotes the worst imaginable pain.

Patients who meet the exclusion criteria will be withdrawn from the study. Participants will be randomly assigned to one of two groups using a computer-generated simple randomization method (https://www.randomizer.org). Randomization will be performed by a team member uninvolved in patient care, who will also prepare sealed opaque envelopes to conceal group allocation until shortly before block administration.

Study Groups and Block Procedures: Group ITP will receive a bilateral ITP block, and Group EOIPB will receive a bilateral EOIP block. All patients will be monitored with electrocardiography, peripheral oxygen saturation (SpO#), and non-invasive blood pressure prior to the block. Premedication with intravenous midazolam (0.02 mg/kg) will be administered.

ITP Block :

Intertransverse Process Block (ITP) will be performed 30 minutes prior to surgery with the patient in a sitting position. After skin disinfection with chlorhexidine, the skin and subcutaneous tissues will be anesthetized using 2-4 mL of 1% lidocaine (Aritmal®, Osel Pharmaceuticals, Turkey). A linear ultrasound probe (Mindray Diagnostic Ultrasound System, Model DC-T6) will be positioned along the medial border of spinous processes level of the T7/T8 thoracic vertebrae.

Anatomical landmarks, including the erector spinae muscle, transverse processes, and superior costotransverse ligament complex at the T7/T8 level, will be identified. Using an in-plane approach, a 21 G 0.8x100 mm echogenic insulated needle (Echoplex®+ , Vygon SA, Écouen, France) will be inserted through the erector spinae muscle toward the intertransverse tissue complex located between the superior costotransverse ligament and the transverse processes. Proper needle placement will be confirmed with the injection of 1-2 mL isotonic saline demonstrating separation within the intertransverse plane. Upon confirmation and negative aspiration, 20 mL of 0.25% bupivacaine hydrochloride (Buvasin®, Vem Pharmaceuticals, Turkey) will be administered on each side under ultrasound guidance.

External Oblique Intercostal Plane Block:

External Oblique Intercostal Plane Block (EOIPB) will be performed 30 minutes prior to surgery with the patient in a supine position. After skin disinfection with chlorhexidine, the skin and subcutaneous tissues will be anesthetized using 2-4 mL of 1% lidocaine (Aritmal®, Osel Pharmaceuticals, Turkey). A linear ultrasound probe (Mindray Diagnostic Ultrasound System, Model DC-T6) will be positioned in a sagittal orientation along the midaxillary line at the level of the sixth rib.

Anatomical landmarks, including the external oblique muscle, intercostal muscles, and ribs will be identified. Using an in-plane approach, a 21G 0.8×100 mm echogenic insulated needle (Echoplex®+ , Vygon SA, Écouen, France) will be inserted into the fascial plane between the external oblique muscle and the intercostal muscles. Proper needle placement will be confirmed with the injection of 1-2 mL isotonic saline. Upon confirmation and negative aspiration, 20 mL of 0.25% bupivacaine hydrochloride (Buvasin®, Vem Pharmaceuticals, Turkey) will be administered on each side under ultrasound guidance.

General Anesthesia Upon entry into the operating room, patients will be monitored with electrocardiography, peripheral oxygen saturation (SpO#), and non-invasive blood pressure. Anesthesia will be induced with intravenous propofol (2 mg/kg, Polifarma Pharmaceutical Industry and Trade Inc., Ergene, Turkey), fentanyl citrate (1.5 mcg/kg, Polifarma Pharmaceutical Industry and Trade Inc., Ergene, Turkey), and rocuronium bromide (0.6 mg/kg, Muscuron®, Koçak Farma Pharmaceutical and Chemical Industry Co., Turkey). Anesthesia maintenance will be provided using 6% desflurane in a 40% oxygen-air mixture and a continuous remifentanil infusion at 0.05 mcg/kg/min. Mechanical ventilation settings will be adjusted to deliver a tidal volume of 6-8 mL/kg with end-tidal CO# maintained at 30-35 mmHg. Anesthetic depth will be monitored continuously using a Bispectral Index (BIS™) monitor (Medtronic plc, Dublin, Ireland), targeting a BIS value of 40-60. If heart rate or mean arterial pressure increases >20% from baseline, the remifentanil dose will be titrated accordingly.

Thirty minutes before the end of surgery, all patients will receive 15 mg/kg of intravenous paracetamol (e.g., Paracerol®, Polifarma Pharmaceutical Industry and Trade Inc., Ergene, Turkey) and 1 mg/kg of intravenous tramadol. To prevent nausea and vomiting, 4 mg intravenous ondansetron will be administered. Patients with adequate spontaneous ventilation will be extubated and transferred to the post-anesthesia care unit (PACU). Hemodynamic Monitoring Heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and oxygen saturation will be recorded at the following time points: pre-induction (baseline), 5 minutes after induction, 5 minutes after surgical incision, 15 minutes after incision, and at the end of surgery.

Postoperative Pain and Analgesic Use: Pain will be assessed using the VAS at rest (static) and during movement (dynamic) at 0, 1, 4, 8, 12, and 24 hours postoperatively.

All patients will use patient-controlled analgesia (PCA) without a basal infusion. The PCA device will be set to deliver 1 mg of morphine (0.2 mg/mL concentration) with a 10-minute lockout interval. Patients will be instructed to press the PCA button when VAS ≥4. Intravenous paracetamol will be administered every 8 hours.

Rescue analgesia with intravenous tramadol (1 mg/kg) will be provided if VAS scores remain ≥4. The total amounts of opioids, NSAIDs, and other analgesics will be recorded.

Postoperative Recovery Quality Postoperative recovery will be assessed using the 15-item Quality of Recovery-15 (QoR-15) questionnaire, which evaluates five domains: pain, physical comfort, physical independence, psychological support, and emotional state.

Patient Satisfaction Satisfaction will be evaluated using a 5-point Likert scale, where 1 = not satisfied and 5 = very satisfied, based on verbal feedback from both the patient and the surgeon.

Nausea and Vomiting: Nausea and vomiting will be scored using a 4-point scale:

0 = none

1. = mild
2. = moderate
3. = severe

Potential Complications Any complications associated with the block or the surgical procedure (e.g., hematoma, pneumothorax, local anesthetic systemic toxicity, vascular puncture, or infection) will be recorded.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: ENES ESKİN, CONSULTANT İN ANESTHESİOLOGY; Phone Number: +905454738489; Email: eneskin@hotmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients aged 18-65 years
• ASA physical status I-III
• Scheduled for elective laparoscopic sleeve gastrectomy
• Body mass index (BMI) >35 kg/m²
• Ability to understand and use the patient-controlled analgesia (PCA) device
• Ability to provide written informed consent

Exclusion Criteria:

• Refusal to participate
• Allergy to local anesthetics
• Infection at the injection site
• Coagulopathy or ongoing anticoagulant therapy
• Chronic opioid use or opioid dependence
• Severe hepatic or renal insufficiency
• Pregnancy or breastfeeding
• Cognitive impairment or inability to communicate pain scores
• Body mass index (BMI) >35 kg/m²

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intertransverse Process Block (ITPB)	Procedure: Intertransverse Process Block; Ultrasound System, Model DC-T6) will be positioned along the medial border of spinous processes level of the T7/T8 thoracic vertebrae. Anatomical landmarks, including the erector spinae muscle, transverse processes, and superior costotransverse ligament complex at the T7/T8 level, will be identified. Using an in-plane approach, a 21 G 0.8x100 mm echogenic insulated needle will be inserted through the erector spinae muscle toward the intertransverse tissue complex located between the superior costotransverse ligament and the transverse processes. Proper needle placement will be confirmed with the injection of 1-2 mL isotonic saline demonstrating separation within the intertransverse plane. Upon confirmation and negative aspiration, 20 mL of 0.25% bupivacaine hydrochloride will be administered on each side under ultrasound guidance.
Active Comparator: External Oblique Intercostal Plane Block (EOIPB)	Procedure: External Oblique Intercostal Plane Block; After skin disinfection with chlorhexidine, the skin and subcutaneous tissues will be anesthetized using 2-4 mL of 1% lidocaine. A linear ultrasound probe will be positioned in a sagittal orientation along the midaxillary line at the level of the sixth rib. Anatomical landmarks, including the external oblique muscle, intercostal muscles, and ribs will be identified. Using an in-plane approach, a 21G 0.8×100 mm echogenic insulated needle will be inserted into the fascial plane between the external oblique muscle and the intercostal muscles. Proper needle placement will be confirmed with the injection of 1-2 mL isotonic saline. Upon confirmation and negative aspiration, 20 mL of 0.25% bupivacaine hydrochloride will be administered on each side under ultrasound guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative pain intensity (VAS score)	Postoperative pain will be assessed using the visual analog scale (VAS), ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores represent greater pain intensity.	0, 1, 4, 8, 12, and 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
İncedence of postoperative nausea and vomiting		Within the first 24 hours postoperatively
Total opioid consumption via patient-controlled analgesia (PCA)		Within the first 24 hours postoperatively
Quality of recovery assessed using the QoR-15 questionnaire	Quality of recovery will be assessed using the Quality of Recovery-15 (QoR-15) questionnaire, which ranges from 0 to 150, with higher scores indicating better recovery.	At 24 hours postoperatively
Potential Complications	Any complications associated with the block or the surgical procedure (e.g., hematoma, pneumothorax, local anesthetic systemic toxicity, vascular puncture, or infection) will be recorded.	Within the first 24 hours postoperatively
Requirement for rescue analgesia		Within the first 24 hours postoperatively]
Patient satisfaction	Patient satisfaction will be assessed using Likert scala (1 =very dissatisfied, 2 = dissatisfied, 3 = neutral, 4 = satisfied, 5 = very satisfied). Higher scores indicate greater satisfaction.	At 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Antalya City Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): December 15, 2026
• Primary Completion (Estimated): November 30, 2027
• Study Completion (Estimated): December 30, 2027

Study Registration Dates

• First Submitted: May 9, 2026
• First Submitted That Met QC Criteria: May 9, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 9, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: ITP; EOIPB
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: ITP-EOIBP

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