Transversalis Fascia Plane Block Versus Low-Dose Intrathecal Morphine for Open Inguinal Hernia Repair

Comparison of Ultrasound-Guided Transversalis Fascia Plane Block and Low-Dose Intrathecal Morphine for Postoperative Analgesia After Open Inguinal Hernia Repair: A Prospective Randomized Controlled Trial

Open inguinal hernia repair is commonly associated with early postoperative pain, which may delay mobilization, reduce patient satisfaction, and increase opioid consumption. Low-dose intrathecal morphine may provide prolonged postoperative analgesia after spinal anesthesia; however, it may also be associated with opioid-related adverse effects such as nausea, vomiting, pruritus, urinary retention, sedation, and respiratory depression.

The transversalis fascia plane block is an ultrasound-guided fascial plane block that targets the sensory innervation of the lower abdominal wall, particularly the T12-L1 dermatomal region and the ilioinguinal and iliohypogastric nerve distribution. Although TFP block has been evaluated in lower abdominal procedures, direct comparison with low-dose intrathecal morphine in open inguinal hernia repair is limited.

This prospective, randomized, controlled, assessor-blinded trial aims to compare ultrasound-guided TFP block with low-dose intrathecal morphine in adult patients undergoing elective unilateral open inguinal hernia repair under spinal anesthesia. The primary outcome is total rescue opioid consumption during the first 24 postoperative hours. Secondary outcomes include pain scores at rest and with movement, time to first rescue analgesia, opioid-related adverse effects, quality of recovery, patient satisfaction, mobilization time, readiness for discharge, block success, sensory block distribution, and block-related complications.

Study Overview

• Status: Recruiting
• Conditions: Postoperative Pain
• Intervention / Treatment: Drug: Intrathecal morphine; Procedure: Ultrasound-guided transversalis fascia plane block

Detailed Description

Adult patients scheduled for elective unilateral open inguinal hernia repair under spinal anesthesia will be enrolled. After written informed consent, eligible patients will be randomly assigned in a 1:1 ratio to one of two groups.

In the intrathecal morphine group, patients will receive spinal anesthesia with 15 mg of 0.5% hyperbaric bupivacaine plus 100 mcg intrathecal morphine. No TFP block will be performed in this group.

In the TFP block group, patients will receive spinal anesthesia with 15 mg of 0.5% hyperbaric bupivacaine without intrathecal morphine. In addition, an ultrasound-guided unilateral TFP block will be performed on the surgical side before surgery using 30 mL of 0.25% bupivacaine, within the maximum safe dose limits.

All patients will receive a standardized multimodal postoperative analgesia protocol. Pain scores, rescue analgesic consumption, opioid-related adverse effects, quality of recovery, and safety outcomes will be recorded during the first 24 postoperative hours. Persistent or chronic postoperative inguinal pain may be evaluated exploratorily during follow-up if sufficient data are available.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sibel Onen Ozdemir, MD; Phone Number: +905442892194; Email: sibelonen89@gmail.com

Study Locations

• Turkey (Türkiye)
  • Çorum, Turkey (Türkiye)
    • Recruiting
    • Hitit university
    • Contact: Ozgur Yagan, Professor

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adult patients aged 18-80 years
• Patients scheduled for elective unilateral open inguinal hernia repair
• ASA physical status I-III
• Patients planned to undergo spinal anesthesia
• Patients able to understand and report postoperative pain scores
• Patients who provide written informed consent

Exclusion Criteria:

• Refusal to participate
• Bilateral inguinal hernia repair
• Recurrent inguinal hernia repair
• Emergency, incarcerated, or strangulated hernia
• Need for general anesthesia
• Contraindication to spinal anesthesia
• Coagulopathy or anticoagulant use contraindicating neuraxial or peripheral block
• Infection at the injection site
• Known allergy to local anesthetics, morphine, or study medications
• Chronic opioid use
• Preoperative chronic groin pain or neuropathic pain history
• Severe hepatic or renal failure
• Neurological or psychiatric condition preventing communication or pain assessment
• Expected inability to complete postoperative follow-up

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intrathecal Morphine Group; Patients will receive spinal anesthesia with 15 mg of 0.5% hyperbaric bupivacaine plus 100 mcg intrathecal morphine. No TFP block will be performed.	Drug: Intrathecal morphine; Patients will receive 100 mcg intrathecal morphine in addition to 15 mg of 0.5% hyperbaric bupivacaine during spinal anesthesia.
Experimental: TFP Block Group; An ultrasound-guided unilateral transversalis fascia plane block will be performed using 30 mL of 0.25% bupivacaine on the surgical side before open inguinal hernia repair. The local anesthetic dose will be adjusted according to patient weight and maximum safe dose limits.	Procedure: Ultrasound-guided transversalis fascia plane block; Patients will receive an ultrasound-guided unilateral transversalis fascia plane block on the surgical side using 30 mL of 0.25% bupivacaine before surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Rescue Opioid Consumption During the First 24 Postoperative Hours	Total rescue opioid analgesic consumption during the first 24 postoperative hours will be recorded and converted to intravenous morphine equivalents.	0-24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of Recovery Score	Quality of recovery will be assessed using the QoR-15 score. The total score ranges from 0 to 150, with higher scores indicating better recovery.	24 hours after surgery
Opioid-Related Adverse Effects	Nausea, vomiting, pruritus, urinary retention, sedation, respiratory depression, and oxygen desaturation will be recorded.	0-24 hours after surgery

Collaborators and Investigators

• Sponsor: Hitit University

Study record dates

Study Major Dates

• Study Start (Actual): June 23, 2026
• Primary Completion (Estimated): October 23, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: July 6, 2026
• First Submitted That Met QC Criteria: July 6, 2026
• First Posted (Actual): July 10, 2026

Study Record Updates

• Last Update Posted (Actual): July 10, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Intrathecal morphine; Postoperative analgesia; Regional anesthesia; Opioid consumption; Transversalis fascia plane block
• 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: 2026-32

Drug and device information, study documents

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