EOIFP Block Versus OSTAP Block for Upper Abdominal Surgery

March 16, 2026 updated by: The Cleveland Clinic

A Feasibility Pilot Study Assessing the Effects of External Oblique Intercostal Fascial Plane Block Versus Subcostal TAP Block for Upper Abdominal Surgery: A Randomized, Controlled Trial

The investigators propose a single-center, assessor blinded, randomized control trial to compare the efficacy of external oblique fascial plane (EOIFP) block versus Oblique Subcostal Transversus Abdominis Plane (OSTAP) block for patients undergoing open upper abdominal surgery at Cleveland Clinic Main Campus.

Study Overview

Detailed Description

The investigators propose a single-center, assessor blinded, randomized control trial to compare the efficacy of external oblique fascial plane (EOIFP) block versus Oblique Subcostal Transversus Abdominis Plane (OSTAP) block for patients undergoing open upper abdominal surgery at Cleveland Clinic Main Campus..

Participating patients and outcome assessors will be blinded to group assignment. The anesthesiologists who perform the blocks will not be blinded to group assignment.

American Society of Anesthesiologists (ASA) physical status 1-3 adults scheduled for elective open upper abdominal surgery with supraumbilical incision, with anticipated 3 days postoperative hospitalization, at Cleveland Clinic Main Campus will be included in the study. Patients will be excluded if they have chronic hepatic or kidney disease. Pregnant or breastfeeding participants will not be eligible for this study.

Patients will be randomly assigned to: 1) EOIFP block or 2) OSTAP block. The location of each block will be performed as previously described. The procedure will be performed using sterile technique under ultrasound guidance. Once the target is visualized, a 20-gauge, 4-inch echogenic needle will be advanced in-plane to the fascial plane. 5 ml of 0.9% normal saline will be injected through the needle to open the fascial plane and then a single dose (10 ml) of liposomal bupivacaine mixed with 20 mL of bupivacaine 0.25% will be injected on each side. General anesthesia will be induced at the attending anesthesiologist's discretion and maintained with sevoflurane or isoflurane. Intraoperative analgesic use will be up to the anesthesiologist preference. Postoperatively, patients will be given IV Dilaudid &/or fentanyl, &/or morphine equivalent for pain relief as needed, as well as oral Tylenol 1000mg every 8 hours unless contraindicated. Toradol can be given as part of multimodal analgesia if cleared by the surgical team. Clinicians will adjust analgesic management as necessary in an effort to keep verbal response pain scores <4. Nurses will adjust analgesic management as necessary in an effort to keep verbal response pain scores <4.

Other anti-inflammatory drugs will not be used intraoperatively or for the initial 48 postoperative hours. A single dose of dexamethasone (4-8 mg) will be permitted for PONV prophylaxis for patients with Apfel risk score of 2 or more, and inhaled steroids will be permitted as necessary to treat reactive airway disease. Other opioid sparing medications like gabapentin, pregabalin, ketamine or lidocaine patch will also not be permitted through the initial 48 postoperative hours.

Clinical evaluators for the outcomes will be blinded to study aim and Pharmacy personnel not involved in evaluations will prepare the study drugs. Patients will be continuously monitored and recorded with a wireless monitor starting after extubation in the operating room. Clinicians including nurses will be blinded to monitoring and will be required to perform their standard of care management after surgery.

Patients will be allowed to receive prophylactic anti-emetic (first choice ondansetron) intraoperatively based on the risk assessment for nausea and vomiting. Postoperative anti-emetics for symptomatic treatment will also be allowed.

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Ehab Farag, MD
  • Phone Number: 216 870-8719
  • Email: farage@ccf.org

Study Locations

    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Recruiting
        • Cleveland Clinic Foundation
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Written informed consent;
  • 18-85 years old;
  • ASA Physical Status 1-3
  • Scheduled for elective open upper abdominal surgery with supraumbilical incision (gastrectomy, hepatectomy, pancreatectomy, splenectomy, supraumbilical ventral hernia repair).
  • Anticipated hospitalization of three nights;
  • Expected requirement for parenteral opioids for at least 48 hours for postoperative pain

Exclusion Criteria:

  • Hepatic disease, e.g. twice the normal levels of liver enzymes;
  • Chronic kidney disease according to GFR (may be stage 3 or worse as defined by a GFR <60
  • Allergic reaction to study medications;
  • Women who are pregnant or breastfeeding;
  • Nephrectomy or lower abdominal surgeries such as hysterectomy, colorectal surgeries
  • Patient refusal

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Oblique Subcostal Transversus Abdominis Plane Block
Researchers will perform the Oblique Subcostal Transversus Abdominis Plane Block using sterile technique under ultrasound guidance. Once the target is visualized, a 20-gauge, 4-inch echogenic needle will be advanced in-plane to the fascial plane. 5 ml of 0.9% normal saline will be injected through the needle to open the fascial plane and then a single dose (10 ml) of liposomal bupivacaine mixed with 20 mL of bupivacaine 0.25% will be injected on each side.
With the OSTAP block, local anesthetic is injected into the fascial plane between the posterior rectus sheath and the transversus abdominis muscle beneath the subcostal margin.
Other Names:
  • OSTAP
Experimental: External Oblique Intercostal Fascial Plane block
Researchers will perform the External Oblique Intercostal Fascial Plane block using sterile technique under ultrasound guidance. Once the target is visualized, a 20-gauge, 4-inch echogenic needle will be advanced in-plane to the fascial plane. 5 ml of 0.9% normal saline will be injected through the needle to open the fascial plane and then a single dose (10 ml) of liposomal bupivacaine mixed with 20 mL of bupivacaine 0.25% will be injected on each side.
With the EOIF block, local anesthetic targets the terminal part of the thoracoabdominal nerves pass behind the costal cartilage and continue anteriorly in the plane between the internal oblique and transversus abdominis muscle, before piercing the rectus abdominis sheath as anterior cutaneous branches supplying the skin of the midabdomen.
Other Names:
  • EOIFP

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
feasibility for the learning curve of EOIFP Vs OSTAP
Time Frame: 3 days
Evaluate feasibility for the learning curve of the new technique of EOIFP versus the standard technique of OSTAP
3 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Ehab Farag, MD, The Cleveland Clinic

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 26, 2024

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

May 7, 2024

First Submitted That Met QC Criteria

May 9, 2024

First Posted (Actual)

May 10, 2024

Study Record Updates

Last Update Posted (Actual)

March 18, 2026

Last Update Submitted That Met QC Criteria

March 16, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 23-417

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

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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