Analgesic Efficacy of Ultrasound-guided External Oblique Intercostal Plane Block Versus Posterior Transversus Abdominis Plane Block in Patients Undergoing Open Nephrectomy

Analgesic Efficacy of Ultrasound-guided External Oblique Intercostal Plane Block Versus Posterior Transversus Abdominis Plane Block in Patients Undergoing Open Nephrectomy: A Randomized Double-blinded Comparative Study

Renal cell carcinoma (RCC) accounts for 2-3% of all cancers and is a common malignancy of the genitourinary tract. Open nephrectomy, performed through midline, subcostal, or flank incisions, remains a standard treatment but often results in significant postoperative pain, leading to respiratory muscle dysfunction, increased pulmonary complications, and prolonged hospital stays.

Acute surgical pain arises from inflammatory responses, activation of spinal pain pathways, and muscle spasms. While postoperative pain typically improves during recovery, some patients develop chronic postsurgical pain (CPSP), lasting at least two months postoperatively.

Opioids and epidural analgesia are commonly used for pain control, but their side effects and invasiveness necessitate safer, effective alternatives. Ultrasound (US)-guided peripheral nerve and field blocks have become integral to multimodal analgesia. One such technique, the **external oblique intercostal plane block (EOIPB)**, was introduced as a modification of fascial plane blocks, targeting anterior and lateral cutaneous nerves (T6-T10). EOIPB offers advantages over quadratus lumborum block (QLB) and erector spinae plane block (ESPB) by being performed in the supine position and providing superior midline analgesia compared to serratus intercostal plane block (SIPB).

Similarly, the transversus abdominis plane (TAP) block, particularly the posterior approach, delivers analgesia from T7 to T12 by anesthetizing anterior and lateral cutaneous nerve branches. While case series suggest EOIPB may be effective for post-nephrectomy pain, comparative studies between EOIPB and posterior TAP block in open nephrectomy:

Aim of the Study:

To evaluate the postoperative analgesic effects of posterior transversus abdominis plane (TAP) block and external oblique intercostal plane block (EOIPB) in patients undergoing open nephrectomy under general anesthesia.

Study Overview

• Status: Recruiting
• Conditions: Postoperative Pain
• Intervention / Treatment: Procedure: US-guided external oblique intercostal plane block (EOIPB)

• Study Type: Interventional
• Enrollment (Estimated): 56
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Abeer A Mohamed; Phone Number: 01005244590; Email: abeer_ahmed@kasralainy.edu.eg

Study Locations

• Egypt
  • Cairo, Egypt, 00225
    • Recruiting
    • Kasr Alainy Faculty of Medicine - Cairo university
    • Contact: Abeer Ahmed, MD
  • Cairo Governorate
    • Maadi, Cairo Governorate, Egypt, 11728
      • Completed
      • Abeer Ahmed Mohamed

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients whom diagnosed as having renal carcinoma and scheduled for open nephrectomy under general anesthesia.
• ASA class II- III.
• Age ≥ 18 and ≤ 70 years.
• Body mass index (BMI) less than 40kg/m2.

Exclusion Criteria:

1. Patient refusal.
2. Hepatic and renal insufficiency.
3. Unstable cardiovascular or pulmonary disease.
4. History of psychiatric and cognitive disorders.
5. Patients with known sensitivity or contraindications to the drug used.
6. Patients on regular opioid consumption.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: EOIPB-Group	Procedure: US-guided external oblique intercostal plane block (EOIPB); US Guided external oblique intercostal plane block (EOIPB) or Posterior TAP Block: Other Names: US Guided Posterior TAP Block:
Active Comparator: Posterior TAP - Group	Procedure: US-guided external oblique intercostal plane block (EOIPB); US Guided external oblique intercostal plane block (EOIPB) or Posterior TAP Block: Other Names: US Guided Posterior TAP Block:

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Postoperative morphine consumption (mg) in the first 24 hrs .	Time elapsed from the end of the block procedure till the end of the 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: March 9, 2025
• First Submitted That Met QC Criteria: March 22, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): June 1, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• 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: MS-389-2024

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No