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.

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.

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