RISS Versus Lower Thoracic ESP Block for Analgesia After Laparoscopic Abdominal Surgery: A Randomized Trial

Summary

The goal of this clinical trial is to investigate the analgesic efficacy of ultrasound-guided Romboid Intercostal and Subserratus (RISS) block versus lower thoracic Erector Spinae Plane (ESP) block after laparoscopic abdominal surgery. The main questions it aims to answer are:

Does ultrasound-guided Romboid Intercostal and Subserratus (RISS) block is effective as the lower thoracic Erector Spinae Plane (ESP) block for intra and postoperative analgesia after laparoscopic abdominal surgery for the first 24 hours? What complications do participants have when doing these interventions?

Researchers will compare the analgesic efficacy of ultrasound-guided Romboid Intercostal and Subserratus (RISS) block with the lower thoracic Erector Spinae Plane (ESP) block after laparoscopic abdominal surgery.

Participants will:

Start general anesthesia and be given either block according to the randomization chart.

The blood pressure and heart rate will be measured at intervals to determine if the participants need extra intraoperative analgesics.

Numerical Rating Scale (NRS) will be used postoperatively to test pain severity.

Rescue morphine analgesia will be measured and compared in both groups.

Any complications will be reported.

Patient and surgeon satisfaction will be measured.

Conditions

• Pain After Surgery

Interventions

PROCEDURE

Group A (n=35): Ultrasound-guided RISS block (RISS):

The patient will be positioned in the lateral decubitus with the ipsilateral arm abducted to move the scapula laterally and open the intercostal and subscapular spaces. A high-frequency linear probe (10-14 MHz) will be applied 1-2 cm medial to the medial scapular border in an oblique-sagittal plane at the T5-T6 level. Using an in-plane approach, a 22 G, 80 mm block needle will be advanced from superomedial to inferolateral (cephalocaudal) until the tip lies between RM and ICM. After negative aspiration and hydrodissection with 1-2 ml saline, 10 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time observation of spread deep to RM. The probe will then be slid caudally and laterally to the T8-T9 level to visualize the fascial plane at the mid-axillary line between the serratus anterior (SA) muscle and the external intercostal muscle to inject the other 10 ml of local anesthetic.

PROCEDURE

Group B (n=35): Ultrasound-guided lower thoracic ESP block

The patient will be positioned laterally. A linear probe will be placed 3 cm lateral to the posterior midline at the T8-T9 level to identify the transverse process (TP) and erector spinae muscle (ESM). A 22 G, 80 mm Echogenic block needle will be advanced in-plane from cranial to caudal until the tip rests deep to ESM but superficial to the TP. After negative aspiration, 20 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time ultrasound confirmation of longitudinal spread cranially and caudally along the fascial plane. The block will be performed bilaterally following the same stepsA solution composed of 20 ml mixed xylocaine 1% + 0.25 % bupivacaine + 4 mg dexamethasone on each side.

Sponsors & Collaborators

• Misr University for Science and Technology

  lead OTHER

Principal Investigators

• Manar M ElKholy, Profesor · Prof. of Anesth, Kasr Alainy hospital, Faculty of Medicine, Cairo University

• Mohamed Abdelaziz Taha, Assist. Prof. · Assist. Prof. of Anesth, Souad Kafafi University hospital, Faculty of Medicine, MUST

• Ahmed SK Elkhodary, Lecturer · Lecturer of surgery at Souad Kafafi University hospital, Faculty of Medicine, MUST

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-05-20

Primary Completion

2026-12-31

Completion

2026-12-31

Countries

• Egypt

Study Locations