Comparison of Postoperative Analgesic Efficacy of Two Different Blocks in Modified Radical Mastectomy Surgery

Official title

Comparison of Postoperative Analgesic Efficacy of Superior Posterior Serratus Intercostal Plane Block (SPSIP) and Anterior Serratus Plane Block in Modified Radical Mastectomy Surgery

Overview

Postoperative pain following modified radical mastectomy remains a significant clinical challenge and may delay recovery, impair patient comfort, and increase opioid consumption. Ultrasound-guided fascial plane blocks have become an important component of multimodal analgesia for breast surgery. The serratus anterior plane block (SAPB) is an established regional anesthesia technique that provides effective postoperative analgesia. The serratus posterior superior intercostal plane block (SPSIPB) is a recently described interfascial block with promising analgesic effects, but evidence comparing its efficacy with SAPB in breast surgery remains limited. This prospective, randomized, double-blind, single-center clinical trial aims to compare the postoperative analgesic efficacy of ultrasound-guided SPSIPB and SAPB in patients undergoing modified radical mastectomy under general anesthesia. Seventy female patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I-III will be randomly assigned to receive either SPSIPB or SAPB before surgery. The primary outcome is postoperative pain intensity assessed using the Visual Analog Scale (VAS). Secondary outcomes include intraoperative remifentanil consumption, cumulative tramadol consumption during the first 24 postoperative hours, postoperative nausea and vomiting (PONV), quality of recovery assessed with the QoR-40 questionnaire, rescue analgesic requirements, and block-related complications. The findings of this study are expected to provide evidence regarding the comparative effectiveness and safety of these two interfascial plane blocks for postoperative analgesia in breast cancer surgery.

Detailed description

Breast cancer surgery, particularly modified radical mastectomy, is frequently associated with moderate to severe postoperative pain. Inadequate pain control may impair respiratory function, delay mobilization, prolong hospital stay, increase opioid consumption, and contribute to the development of persistent postsurgical pain. Therefore, effective multimodal analgesia incorporating regional anesthesia techniques has become an important component of perioperative care in breast surgery.

Among ultrasound-guided fascial plane blocks, the serratus anterior plane block (SAPB) has been widely adopted because of its ability to block the lateral cutaneous branches of the intercostal nerves, resulting in reduced postoperative pain scores and opioid requirements. More recently, the serratus posterior superior intercostal plane block (SPSIPB) has been introduced as a novel interfascial block that may provide broader thoracic dermatomal spread through injection between the serratus posterior superior and intercostal muscles. Although early clinical reports have demonstrated promising analgesic efficacy, comparative evidence between SPSIPB and SAPB in breast surgery remains limited.

This study is designed as a prospective, randomized, double-blind, single-center clinical trial to compare the analgesic efficacy of ultrasound-guided SPSIPB and SAPB in patients undergoing modified radical mastectomy under general anesthesia. Seventy female patients aged 18 to 65 years with American Society of Anesthesiologists (ASA) physical status I-III who meet the eligibility criteria will be enrolled after providing written informed consent. Participants will be randomized in a 1:1 ratio using sealed-envelope allocation to receive either ultrasound-guided SPSIPB or SAPB before induction of general anesthesia. Both blocks will be performed using 30 mL of 0.25% bupivacaine under standardized ultrasound guidance by experienced anesthesiologists.

General anesthesia and postoperative analgesic management will be standardized for all participants. Intraoperative anesthetic management will include propofol, fentanyl, rocuronium, sevoflurane, and remifentanil according to institutional practice. Following surgery, all patients will receive standardized multimodal analgesia consisting of intravenous paracetamol, tramadol patient-controlled analgesia (PCA), and rescue analgesics when clinically indicated.

The primary outcome is postoperative pain intensity assessed using the Visual Analog Scale (VAS) at predefined postoperative time points. Secondary outcomes include intraoperative remifentanil consumption, cumulative tramadol consumption during the first 24 postoperative hours, postoperative nausea and vomiting (PONV) scores, rescue analgesic requirements, quality of recovery measured using the QoR-40 questionnaire at 24 hours, block-related complications, and other postoperative adverse events.

The findings of this study are expected to clarify whether SPSIPB provides analgesia comparable or superior to SAPB for patients undergoing breast cancer surgery. The results may contribute to optimizing regional anesthesia strategies and improving postoperative recovery while reducing perioperative opioid consumption.

Interventions

• Procedure Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block (SPSIPB)
  An ultrasound-guided serratus posterior superior intercostal plane block will be performed before induction of general anesthesia using 30 mL of 0.25% bupivacaine injected into the fascial plane between the serratus posterior superior muscle and the intercostal muscles.
• Procedure Ultrasound-Guided Serratus Anterior Plane Block (SAPB)
  Ultrasound-guided injection of 30 mL of 0.25% bupivacaine into the serratus anterior plane before induction of general anesthesia.

Primary outcome measures

• Postoperative pain intensity [Time frame: 24 hours after surgery (assessed at PACU arrival, 30 minutes, 2, 4, and 24 hours postoperatively)]

Secondary outcome measures (6)

• Intraoperative remifentanil consumption [Time frame: During surgery]
• Postoperative tramadol consumption [Time frame: 24 hours after surgery]
• Postoperative nausea and vomiting [Time frame: 24 hours after surgery]
• Quality of recovery [Time frame: 24 hours after surgery]
• Rescue analgesic requirement [Time frame: 24 hours after surgery]
• Block-related complications [Time frame: From block performance until 24 hours after surgery]

Eligibility criteria

Inclusion criteria

• Female patients aged 18 to 65 years.
• Scheduled for elective modified radical mastectomy under general anesthesia.
• American Society of Anesthesiologists (ASA) physical status I-III.
• Body mass index (BMI) <35 kg/m².
• Normal coagulation profile (including INR and platelet count).
• Normal liver and renal function tests.
• Able to understand the study procedures and provide written informed consent.

Exclusion criteria

• Known allergy or hypersensitivity to local anesthetics.
• Coagulation disorders or bleeding diathesis.
• Infection or inflammation at the planned block site.
• ASA physical status IV or higher.
• Chronic opioid use or chronic pain requiring long-term analgesic therapy.
• Advanced hepatic or renal insufficiency.
• Severe pulmonary disease.
• Opioid use within 24 hours before surgery.
• Cognitive impairment or inability to complete postoperative assessments.
• Revision breast surgery.
• Refusal to participate in the study.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• Tang W, Luo G, Lu Y, Chen C, Liu H, Li Y. Application of a new serratus anterior plane block in modified radical mastectomy under ultrasound guidance: A prospective, randomized controlled trial. J Clin Anesth. 2021 Nov;74:110377. doi: 10.1016/j.jclinane.2021.110377. Epub 2021 Jun 9. PMID 34118568
• Meng J, Zhao HY, Zhuo XJ, Shen QH. Postoperative Analgesic Effects of Serratus Anterior Plane Block for Thoracic and Breast Surgery: A Meta-analysis of Randomized Controlled Trials. Pain Physician. 2023 Mar;26(2):E51-E62. PMID 36988359
• Ciftci B, Alver S, Ahiskalioglu A, Bilal B, Tulgar S. Serratus posterior superior intercostal plane block for breast surgery: a report of three cases, novel block and new indication. Minerva Anestesiol. 2023 Nov;89(11):1054-1056. doi: 10.23736/S0375-9393.23.17432-3. Epub 2023 Jun 1. No abstract available. PMID 37272274

Identifiers

NCT: NCT07737132 · SBU-ANESTEZİ-DMY-06

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗