SPSIPB Versus SAPB for Postoperative Analgesia After Minimally Invasive Repair of Pectus Excavatum

Comparison of the Postoperative Analgesic Effects of Serratus Posterior Superior Intercostal Plane Block and Serratus Anterior Plane Block After Minimally Invasive Repair of Pectus Excavatum: A Prospective Observational Cohort Study

This prospective observational cohort study will compare postoperative analgesic outcomes in patients undergoing minimally invasive repair of pectus excavatum. Participants will be grouped according to the regional analgesia technique applied as part of routine clinical care: serratus posterior superior intercostal plane block or serratus anterior plane block. The primary outcome will be total opioid consumption during the first 24 hours after surgery. Secondary outcomes will include postoperative pain scores, rescue analgesic requirement, opioid-related adverse effects, patient satisfaction, mobilization time, and length of hospital stay.

Study Overview

• Status: Recruiting
• Conditions: Pectus Excavatum; Chest Deformities
• Intervention / Treatment: Device: Bispectral Index Monitoring; Drug: Postoperative Analgesia Protocol; Procedure: Serratus Anterior Plane Block; Procedure: Serratus Posterior Superior Intercostal Plane Block

Detailed Description

Pectus excavatum is the most common chest wall deformity in pediatric and adolescent patients and is characterized by posterior depression of the sternum and anterior chest wall. Although many patients are asymptomatic, corrective surgery is frequently performed during adolescence or young adulthood for cosmetic reasons and to improve body image and quality of life.

Minimally invasive repair of pectus excavatum involves the placement of a curved metal bar beneath the sternum. The bar is then rotated to elevate the sternum and correct the chest wall deformity. Despite favorable cosmetic and quality-of-life outcomes, postoperative pain remains a major clinical challenge after this procedure. Pain is mainly related to sternal elevation, pressure exerted by the bar, and repositioning of the ribs. Inadequate pain control may increase opioid consumption and prolong hospitalization. Higher opioid exposure may also lead to adverse effects such as nausea, vomiting, constipation, pruritus, and urinary retention.

Regional anesthesia techniques have become important components of multimodal postoperative analgesia in thoracic surgery. Thoracic paravertebral block, erector spinae plane block, and serratus anterior plane block are among the regional techniques commonly used for thoracic analgesia. Serratus anterior plane block has also been used for postoperative pain management after minimally invasive repair of pectus excavatum.

Serratus posterior superior intercostal plane block is a recently described ultrasound-guided interfascial plane block. The technique involves injection of local anesthetic between the serratus posterior superior muscle and the rib, usually at the level of the second or third rib. This block has been reported to provide analgesia in various thoracic and scapular pain conditions and has shown promising results in thoracic surgery.

The aim of this study is to compare the postoperative analgesic outcomes of serratus posterior superior intercostal plane block and serratus anterior plane block in patients undergoing minimally invasive repair of pectus excavatum. Because this is an observational study, the choice of regional analgesia technique will not be determined by the study protocol. The block technique will be selected by the attending anesthesiologist according to routine clinical practice. No randomization or protocol-driven assignment will be performed.

• Study Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: Cem Özdemir, MD; Phone Number: +905385027687; Email: suskungeveze.cem@gmail.com
• Study Contact Backup: Name: Seniyye Ülgen Zengin, Associate Professor, MD; Phone Number: +905057142443; Email: ulgen_t@yahoo.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34722
      • Recruiting
      • Marmara University
      • Contact: Cem Özdemir, MD; Phone Number: +905385027687; Email: suskungeveze.cem@gmail.com
      • Contact: Seniyye Ülgen Zengin, Associate Professor, MD; Phone Number: +905057142443; Email: ulgen_t@yahoo.com
      • Principal Investigator: Seniyye Ülgen Zengin, Associate Professor, MD
      • Sub-Investigator: Cem Özdemir, MD
      • Sub-Investigator: Meliha Orhon Ergün, Associate Professor, MD

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The study population will include patients aged 15 to 25 years who are diagnosed with pectus excavatum and scheduled to undergo minimally invasive repair of pectus excavatum under general anesthesia. Patients who receive either bilateral serratus posterior superior intercostal plane block or bilateral serratus anterior plane block as part of routine perioperative analgesic care will be included.

Description

Inclusion Criteria:

• Patients aged 15 to 25 years
• Diagnosis of pectus excavatum
• Scheduled to undergo minimally invasive repair of pectus excavatum under general anesthesia
• Receipt of either bilateral serratus posterior superior intercostal plane block or bilateral serratus anterior plane block as part of routine perioperative analgesic care
• Written informed consent obtained from the patient or, for patients younger than 18 years, from a legal guardian

Exclusion Criteria:

• Refusal to participate in the study
• Contraindication to regional anesthesia
• Known allergy to local anesthetics or study analgesic medications
• Chronic opioid use
• Pre-existing chronic pain syndrome
• Coagulopathy or use of anticoagulant therapy that contraindicates regional block application
• Local infection at the block injection site
• Neurological or psychiatric condition that may interfere with pain assessment
• Incomplete perioperative or postoperative data
• Conversion to another surgical technique or major intraoperative complication requiring a change in the routine analgesic protocol

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Serratus Anterior Plane Block Group; Participants in this cohort will receive bilateral ultrasound-guided serratus anterior plane block as part of routine perioperative analgesic care.	Device: Bispectral Index Monitoring; Continuous intraoperative depth of anesthesia monitoring using the Bispectral Index (BIS) device. BIS values are recorded throughout the procedure to assist in titration of anesthetic agents and to standardize anesthesia depth across study cohorts. The BIS device is used for monitoring only, and no device-related investigational procedures are performed.; Other Names: BIS Monitoring; BIS; Drug: Postoperative Analgesia Protocol; All participants will receive a standardized multimodal postoperative analgesia protocol. Patient-controlled analgesia with intravenous morphine will be used. The device will be programmed to administer 1 mg of intravenous morphine per demand, with a lockout interval of 10 minutes. Paracetamol will be administered as part of routine multimodal analgesia. If adequate analgesia cannot be achieved, 100 mg tramadol will be administered as rescue analgesia according to clinical need.; Procedure: Serratus Anterior Plane Block; Bilateral ultrasound-guided serratus anterior plane block will be performed according to standard techniques described in the literature and routinely used in the clinic. Local anesthetic dosing will be determined according to institutional practice and safety limits. In bilateral applications, the total bupivacaine dose will not exceed 2.5 mg/kg.; Other Names: SAPB; SAP Block
Serratus Posterior Superior Intercostal Plane Block Group; Participants in this cohort will receive bilateral ultrasound-guided serratus posterior superior intercostal plane block as part of routine perioperative analgesic care.	Device: Bispectral Index Monitoring; Continuous intraoperative depth of anesthesia monitoring using the Bispectral Index (BIS) device. BIS values are recorded throughout the procedure to assist in titration of anesthetic agents and to standardize anesthesia depth across study cohorts. The BIS device is used for monitoring only, and no device-related investigational procedures are performed.; Other Names: BIS Monitoring; BIS; Drug: Postoperative Analgesia Protocol; All participants will receive a standardized multimodal postoperative analgesia protocol. Patient-controlled analgesia with intravenous morphine will be used. The device will be programmed to administer 1 mg of intravenous morphine per demand, with a lockout interval of 10 minutes. Paracetamol will be administered as part of routine multimodal analgesia. If adequate analgesia cannot be achieved, 100 mg tramadol will be administered as rescue analgesia according to clinical need.; Procedure: Serratus Posterior Superior Intercostal Plane Block; Bilateral ultrasound-guided serratus posterior superior intercostal plane block will be performed according to standard techniques described in the literature and routinely used in the clinic. Local anesthetic dosing will be determined according to institutional practice and safety limits. In bilateral applications, the total bupivacaine dose will not exceed 2.5 mg/kg.; Other Names: SPSIPB; SPSIP Block

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total postoperative opioid consumption during the first 24 hours	Total opioid consumption during the first 24 hours after surgery will be recorded and expressed as intravenous morphine equivalents in milligrams.	From the end of surgery to 24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative opioid consumption	Total intraoperative opioid consumption will be recorded.	From induction of anesthesia to the end of surgery
Postoperative pain scores	Pain intensity will be assessed using the Numeric Rating Scale, where 0 indicates no pain and 10 indicates the worst imaginable pain.	At arrival in the post-anesthesia care unit and at postoperative 6, 12, 24, and 48 hours
Patient satisfaction	Patient satisfaction with postoperative analgesia will be assessed using a 4-point Likert scale, where 0 indicates very dissatisfied and 3 indicates very satisfied.	At postoperative 6, 12, 24, and 48 hours
Incidence of Opioid-Related Adverse Effects	Presence of nausea, vomiting, pruritus, constipation, urinary retention, sedation, and respiratory depression. Adverse effects will be compared among the two groups.	From the end of surgery to 48 hours postoperatively
Duration of anesthesia	The total duration of anesthesia will be recorded in minutes.	Intraoperative period
Duration of surgery	The total duration of surgery will be recorded in minutes.	Intraoperative period
Time to mobilization	The time from the end of surgery to first mobilization will be recorded.	From the end of surgery until the first documented ambulation, assessed within the first 48 postoperative hours
Length of hospital stay	The duration of postoperative hospitalization will be recorded.	Length of postoperative hospital stay, defined as the time from the end of surgery to hospital discharge, assessed up to 30 days postoperatively

Collaborators and Investigators

• Sponsor: Marmara University
• Investigators: Study Chair: Cem Özdemir, MD, Marmara University; Principal Investigator: Seniyye Ülgen Zengin, Associate Professor, MD, Marmara University; Study Director: Meliha Orhon Ergün, Associate Professor, MD, Marmara University

Study record dates

Study Major Dates

• Study Start (Actual): June 22, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: June 30, 2026
• First Submitted That Met QC Criteria: July 6, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Postoperative Pain; Regional Anesthesia; Opioid Consumption; Serratus Anterior Plane Block; Pectus excavatum; Multimodal Analgesia; Serratus Posterior Superior Intercostal Plane Block; Opioid-Free Anesthesia; SPSIP Block; SAP Block; Opioid-Related Adverse Effects; Chest Deformity Surgery
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Bone Diseases; Musculoskeletal Diseases; Postoperative Complications; Pathologic Processes; Musculoskeletal Abnormalities; Congenital Abnormalities; Bone Diseases, Developmental; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Funnel Chest
• Other Study ID Numbers: 09.2026.769

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared. The study involves clinical information collected under institutional ethical approval, and no consent was obtained for external sharing of identifiable or de-identified participant-level data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes