Transversus Abdominis Plane Block Versus Ilioinguinal-Iliohypogastric Nerve Block for Postoperative Analgesia Following Open Total Abdominal Hysterectomy

A Comparative Study Between Ultrasound-guided Transversus Abdominis Plane Block Versus Ultrasound-guided Ilioinguinal-Iliohypogastric Nerve Block for Postoperative Analgesia Following Open Total Abdominal Hysterectomy: A Randomised Comparative Trial

The investigators hypothesised that ultrasound-guided transversus abdominis plane (TAP) block would prolong the time to first rescue nalbuphine within 24 hours compared with ultrasound-guided ilioinguinal-iliohypogastric (IIH) nerve block, by virtue of its broader dermatomal coverage (T10-L1 versus T12-L1) of the Pfannenstiel incision. This hypothesis direction was established before unblinding and data analysis.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain
• Intervention / Treatment: Procedure: Transverse Abdominis Plane Block; Procedure: Ilioinguinal-iliohypogastric block

Detailed Description

Aim of the work

the aim of the study is to compare between the analgesic effect of Transversus Abdominis Plane Block and Ilioinguinal-iliohypogastric block following open abdominal hysterectomy Objectives

• to compare between the analgesic effect of Transversus Abdominis Plane Block and Ilioinguinal-iliohypogastric block For Postoperative Analgesia following open abdominal hysterectomy
• to measure the incidence of complications following both blocks as hematoma, block failure, infection at injection site

Sample size:

Our primary outcome is the time to first rescue analgesia request. In a previous study, the meantime to first rescue analgesia was 10.58 ± 2.35 hours (6). The investigators calculated a sample size that could detect a mean difference of 20% between both study groups. MedCalc Software version 14 (MedCalc Software bvba, Ostend, Belgium) was used to calculate the sample size.38 patients( 19 patients per group) at least were estimated to have a study power of 80% and an alpha error of 0.05. This number will be increased to 42 patients (21 patients per group) to compensate for possible dropouts.

Sample size calculation was performed guided by the power of 80%, confidence level of 95%.

Statistical analysis:

For data analysis, the Statistical Package for Social Science (SPSS) software, version 23.0 for Microsoft Windows (SPSS Inc., Chicago, IL, USA) was used (version 23.0 was used in place of the registered version 26; no impact on any statistical result). Python (SciPy 1.7) was additionally used for area-under-the-curve computation and Holm-Bonferroni multiplicity correction.

Normality of continuous data was assessed using the Shapiro-Wilk test and graphical inspection. Parametric data are reported as mean (standard deviation) and were compared between groups using the independent samples t test. Non-parametric data are reported as median (interquartile range [range]) and were compared using the Mann-Whitney U test. Categorical data are reported as number (proportion) and were compared using the chi-square test or Fisher exact test as appropriate.

The primary outcome time from end of surgery to first rescue nalbuphine within 24 hours was analysed as a time-to-event outcome using the Kaplan-Meier method with log-rank testing, and Cox proportional hazards regression was used to estimate the hazard ratio with 95% confidence interval. Participants who did not require rescue nalbuphine were censored at 24 hours. This approach replaced the t-test framework implied in the original registration, as Kaplan-Meier survival analysis is the methodologically appropriate method for a time-to-event outcome with censored observations. This change was made before unblinding and before any outcome data were examined.

To address multiple comparisons across the eight postoperative pain assessment time points, cumulative pain burden was calculated for each participant as the area under the numerical rating scale pain score-time curve from 5 minutes to 24 hours using the trapezoidal rule (NRS-AUC₅ₘᵢₙ-₂₄ₕ, in score·hours) and compared between groups using the Mann-Whitney U test. Individual time-point comparisons were considered exploratory and p values were adjusted using the Holm-Bonferroni stepwise correction in place of the Bonferroni post-hoc ANOVA approach registered originally; this substitution is more statistically appropriate as it controls the familywise error rate with greater power. Cohen's d was calculated from group means and standard deviations as a supplementary standardised effect-size measure.

All tests were two-sided with α = 0.05. Exact p values are reported throughout rather than thresholds (e.g., p < 0.05). All 42 randomised participants completed 24-hour follow-up and were included in the analysis (intention-to-treat).

• Study Type: Interventional
• Enrollment (Actual): 42
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • Mohamed Ollaek
  • Cairo Governorate
    • Cairo, Cairo Governorate, Egypt
      • Faculty of Medicine, Cairo University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 61 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants will be adult patients (35-65 years)
• ASA I-III
• Scheduled for elective open TAH

Exclusion Criteria:

• Patient refusal
• BMI > 40 kg·m-²
• Pregnancy
• Chronic pain requiring daily analgesics
• Any known allergy to local anesthetic, nalbuphine, paracetamol, or diclofenac
• Patients with neurological, psychological disorders or those lacking cooperation
• Patients with anatomic abnormalities at site of injection, skin lesions or wounds at site of proposed needle insertion.
• Patients with bleeding disorders defined as (INR >2) and/ or (platelet count <100,000/µL)
• Patients with hepatic disease e.g. liver cell failure or hepatic malignancy or hepatic enlargement

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: TAP Block; Transversus abdominus plane (TAP) block will be used as postoperative analgesia	Procedure: Transverse Abdominis Plane Block; Group T, will be performed in a supine position after skin sterilization, a linear high-frequency transducer GE Healthcare 12L-RS ultrasound will be placed in the transverse plane to the lateral abdominal wall in the mid-axillary line, between the lower costal margin and iliac crest. The abdominal wall muscles (external oblique, internal oblique, and transversus abdominis) will be visualized. A blunt tip,20-gauge, short bevel needle(B Braun Contiplex 22G echogenic needle, 80-100 mm) will be inserted in-plane and advanced anterior to posterior under continuous visualization until the tip reaches between the internal oblique and the transversus abdominis muscle. After negative aspiration, 20 mL of bupivacaine 0.25%, lidocaine 1% will be injected. Separation of the internal oblique and transversus abdominis with a distinct pocket of local anesthetic in-between will be observed. The procedure will be repeated following the same steps on the other side.
Active Comparator: IIIH Block; Ilioinguinal-iliohypogastric (IIIH) block will be used as postoperative analgesia	Procedure: Ilioinguinal-iliohypogastric block; Group I, will receive an Ultrasound-guided IIIH block that will be performed in a supine position after skin sterilization, a linear high-frequency transducer GE Healthcare 12L-RS ultrasound will be placed on the line between the anterior superior iliac spine and the umbilicus, where 3 layers of muscles (extra-abdominal oblique, intra-abdominal oblique, and transverse abdominis) will be visible on the inner side of the anterior superior iliac spine.A blunt tip,20-gauge, short bevel needle( Braun Contiplex 22G echogenic needle, 80-100 mm) will be inserted in-plane and advanced anterior to posterior under continuous visualization until the tip reaches between the internal oblique and the transversus abdominis muscle next to the iliohypogastric/ilioinguinal nerve. After negative aspiration, 20 mL of bupivacaine 0.25%, lidocaine 1% will be injected. The procedure will be repeated following the same steps on the other side.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to first rescue nalbuphine within 24 hours	Time from end of surgery to first administration of rescue nalbuphine (0.15 mg.kg-¹ intravenously, given when numerical rating scale pain score ≥ 4 at rest after 30 minutes).	From end of surgery to first rescue dose within 24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of postoperative nausea and vomiting	Incidence of postoperative nausea and vomiting	Immediate 24 hours post-operative
Total nalbuphine consumption within 24 hours	Total cumulative dose of rescue nalbuphine (mg) administered to each participant from end of surgery to 24 hours postoperatively.	Immediate 24 hours post-operative
Numerical Rating Scale (NRS)	Pain intensity at rest measured using the Numerical Rating Scale (NRS, 0-10, where 0 = no pain and 10 = worst imaginable pain).	5 minutes, 30 minutes, 2 hours, 4 hours, 8 hours, 12 hours, 18 hours, and 24 hours after arrival in the post-anaesthesia care unit
Intraoperative and postoperative haemodynamics (heart rate and mean arterial pressure)	Heart rate (beats per minute) and mean arterial pressure (mmHg) recorded at baseline (before induction), 1 minute after intubation, every 10 minutes intraoperatively, immediately after extubation, 5 minutes after extubation, and every 10 minutes in the post-anaesthesia care unit for 30 minutes. Postoperative assessments also recorded at 2, 4, 8, 12, 18, and 24 hours.	Baseline, every 10 minutes intraoperatively, immediately after extubation, 5 minutes after extubation, every 10 minutes in PACU for 30 minutes, then at 2, 4, 8, 12, 18, and 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Cairo University
• Investigators: Principal Investigator: Mohamed A Ollaek, MD, Department of Anesthesia, Surgical ICU and Pain Management

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2022
• Primary Completion (Actual): February 28, 2023
• Study Completion (Actual): April 30, 2023

Study Registration Dates

• First Submitted: November 30, 2022
• First Submitted That Met QC Criteria: December 16, 2022
• First Posted (Actual): December 19, 2022

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 25, 2026
• Last Verified: April 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-617-2021

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