Interscalene Brachial Plexus Block Versus Serratus Posterior Superior Intercostal Plane Block for Arthroscopic Shoulder Surgery (SISA)

Comparison of Interscalene Brachial Plexus Block and Serratus Posterior Superior Intercostal Plane Block for Postoperative Analgesia After Arthroscopic Shoulder Surgery: A Prospective, Randomized, Double-Blind Controlled Trial

Arthroscopic shoulder surgery is associated with moderate to severe postoperative pain that may delay recovery and rehabilitation. Interscalene brachial plexus block (ISB) is widely used for postoperative analgesia in shoulder surgery; however, it may be associated with complications such as phrenic nerve paralysis. The serratus posterior superior intercostal plane (SPSIP) block is a recently described fascial plane block that may provide effective analgesia while avoiding some of the limitations of ISB.

This prospective, randomized, double-blind controlled trial aims to compare the analgesic efficacy of ISB and SPSIP block in patients undergoing elective arthroscopic shoulder surgery under general anesthesia. The primary outcome is total postoperative opioid consumption during the first 24 hours after surgery. Secondary outcomes include postoperative pain scores, quality of recovery, time to first rescue analgesia, rescue analgesic requirements, intraoperative opioid consumption, sensory block distribution, motor block characteristics, and block-related complications.

Study Overview

• Status: Recruiting
• Conditions: Postoperative Pain; Shoulder Arthroscopy
• Intervention / Treatment: Procedure: Interscalene Brachial Plexus Block; Drug: Bupivacaine; Procedure: Serratus Posterior Superior Intercostal Plane Block

Detailed Description

Postoperative pain following arthroscopic shoulder surgery can adversely affect patient comfort, early mobilization, rehabilitation, and overall recovery. Although the interscalene brachial plexus block is considered the reference regional anesthesia technique for shoulder surgery, its use may be limited by adverse effects such as hemidiaphragmatic paresis, phrenic nerve involvement, and upper extremity motor weakness.

The serratus posterior superior intercostal plane block is a novel ultrasound-guided fascial plane block targeting the posterior thoracic region. Preliminary evidence suggests that it may provide analgesia extending to the shoulder area through spread to cervical and upper thoracic dermatomes. However, comparative clinical evidence between SPSIP block and ISB for arthroscopic shoulder surgery remains limited.

In this prospective, randomized, double-blind controlled trial, eligible adult patients scheduled for elective arthroscopic shoulder surgery under general anesthesia will be randomly assigned to receive either an ultrasound-guided ISB or SPSIP block. All patients will receive standardized general anesthesia and postoperative multimodal analgesia.

The primary endpoint will be total opioid consumption during the first 24 postoperative hours. Secondary endpoints will include postoperative Numeric Rating Scale (NRS) pain scores at predefined time points, quality of recovery assessed with the QoR-15 questionnaire, intraoperative opioid consumption, time to first rescue analgesic requirement, total rescue analgesic consumption, sensory block distribution, motor block assessment, and block-related adverse events.

The study aims to determine whether SPSIP block can provide postoperative analgesia comparable to ISB while potentially reducing complications associated with brachial plexus blockade.

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

Contacts and Locations

• Study Contact: Name: Mürsel Ekinci, MD; Phone Number: +905067137596; Email: drmurselekinci@gmail.com
• Study Contact Backup: Name: Onur Güneş, MD; Phone Number: +905319418938; Email: onurguness96@gmail.com

Study Locations

• Turkey (Türkiye)
  • Nilüfer
    • Bursa, Nilüfer, Turkey (Türkiye)
      • Recruiting
      • Bursa City Hospital
      • Sub-Investigator: Onur Güneş, MD
      • Principal Investigator: Mürsel Ekinci, MD
      • Contact: Onur Güneş, MD; Phone Number: +905319418938; Email: onurguness96@gmail.com
      • Contact: Mürsel Ekinci, MD; Phone Number: 05067137596; Email: drmurselekinci@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age between 18 and 75 years
• ASA physical status I, II, or III
• Scheduled for elective arthroscopic shoulder surgery under general anesthesia
• Provision of written informed consent

Exclusion Criteria:

• Refusal to participate in the study
• Coagulopathy
• Current anticoagulant therapy
• Infection at the block site
• Previous surgery involving the planned block site
• Known allergy or history of toxicity to local anesthetics
• Hepatic failure
• Renal failure
• Uncontrolled diabetes mellitus
• Cognitive impairment or mental disability preventing reliable assessment
• Chronic opioid use or ongoing chronic pain treatment
• Pregnancy, suspected pregnancy, or breastfeeding
• Chronic pulmonary disease (e.g., COPD or asthma)
• Failed block

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
Experimental: Interscalene Brachial Plexus Block Group; Participants receive an ultrasound-guided interscalene brachial plexus block before induction of general anesthesia for postoperative analgesia during arthroscopic shoulder surgery.	Procedure: Interscalene Brachial Plexus Block; Ultrasound-guided interscalene brachial plexus block performed before induction of general anesthesia for postoperative analgesia in arthroscopic shoulder surgery.; Drug: Bupivacaine; Bupivacaine administered for ultrasound-guided regional anesthesia block.
Experimental: Serratus Posterior Superior Intercostal Plane Block Group; Participants receive an ultrasound-guided serratus posterior superior intercostal plane block before induction of general anesthesia for postoperative analgesia during arthroscopic shoulder surgery.	Drug: Bupivacaine; Bupivacaine administered for ultrasound-guided regional anesthesia block.; Procedure: Serratus Posterior Superior Intercostal Plane Block; Ultrasound-guided serratus posterior superior intercostal plane block performed before induction of general anesthesia for postoperative analgesia in arthroscopic shoulder surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Opioid Consumption During the First 24 Postoperative Hours	Comparison of total postoperative opioid consumption between the interscalene brachial plexus block group and the serratus posterior superior intercostal plane block group during the first 24 hours after surgery.	24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative Remifentanil Consumption	Total remifentanil consumption during surgery.	During surgery
Postoperative Pain Scores	Numeric Rating Scale (NRS) pain scores at rest and during movement, ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain.	0, 2, 4, 8, 16, and 24 hours after surgery
Quality of Recovery (QoR-15)	Quality of Recovery-15 (QoR-15) score assessed 24 hours after surgery. Scores range from 0 to 150, with higher scores indicating better postoperative recovery and patient satisfaction.	24 hours after surgery
Time to First Rescue Analgesic Requirement	Time elapsed from the end of surgery to the first rescue analgesic administration.	First 24 postoperative hours
Rescue Analgesic Consumption	Total rescue analgesic consumption during the postoperative period.	First 24 postoperative hours
Block-Related and Opioid-Related Complications	Incidence of adverse events related to regional anesthesia techniques and opioid administration.	First 24 postoperative hours

Collaborators and Investigators

• Sponsor: Ferit Yetik
• Collaborators: Bursa Sehir Hastanesi
• Investigators: Principal Investigator: Mürsel Ekinci, University of Health Sciences, Bursa Faculty of Medicine, Bursa City Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 25, 2026
• Primary Completion (Estimated): December 15, 2026
• Study Completion (Estimated): December 15, 2026

Study Registration Dates

• First Submitted: June 17, 2026
• First Submitted That Met QC Criteria: June 23, 2026
• First Posted (Actual): June 25, 2026

Study Record Updates

• Last Update Posted (Actual): June 29, 2026
• Last Update Submitted That Met QC Criteria: June 25, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Regional Anesthesia; Interscalene Brachial Plexus Block; Serratus Posterior Superior Intercostal Plane Block; Ultrasound-Guided Nerve Block
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Bupivacaine
• Other Study ID Numbers: 26-AKD-92 (Other Identifier: Bursa City Hospital Clinical Research Ethics Committee)

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