RISS Versus SPSIP Block in Modified Radical Mastectomy (RSMRM)

Comparison of Rhomboid Intercostal-Subserratus Plane Block and Serratus Posterior Superior Intercostal Plane Block for Postoperative Analgesia and Dermatomal Spread After Modified Radical Mastectomy: A Randomized Double-Blind Trial

This prospective randomized double-blind controlled trial aims to compare the postoperative analgesic efficacy and dermatomal spread of rhomboid intercostal-subserratus plane (RISS) block and serratus posterior superior intercostal plane (SPSIP) block in patients undergoing modified radical mastectomy. Postoperative pain scores, opioid consumption, rescue analgesic requirements, block-related complications, and quality of recovery outcomes will be evaluated.

Study Overview

• Status: Recruiting
• Conditions: Breast Cancer; Postoperative Pain
• Intervention / Treatment: Procedure: Rhomboid Intercostal-Subserratus Plane Block; Procedure: Serratus Posterior Superior Intercostal Plane Block

Detailed Description

Breast cancer surgery is frequently associated with moderate to severe postoperative pain, which may negatively affect recovery and increase opioid consumption. Ultrasound-guided fascial plane blocks have become an important component of multimodal analgesia strategies for breast surgery.

The rhomboid intercostal-subserratus plane (RISS) block and serratus posterior superior intercostal plane (SPSIP) block are recently described regional anesthesia techniques that may provide effective postoperative analgesia by blocking the lateral and posterior branches of the thoracic spinal nerves. However, comparative clinical evidence regarding their analgesic efficacy and dermatomal coverage in modified radical mastectomy remains limited.

This prospective randomized double-blind controlled trial will compare RISS block and SPSIP block in adult patients undergoing modified radical mastectomy under general anesthesia. Participants will be randomly allocated to receive either RISS block or SPSIP block before surgery. The primary objective is to compare postoperative opioid consumption. Secondary outcomes include postoperative pain scores, dermatomal sensory spread, time to first rescue analgesia, quality of recovery, opioid-related adverse events, and block-related complications.

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

Contacts and Locations

• Study Contact: Name: Yusuf Alan, MD; Phone Number: +905396210977; Email: dryusufalan@gmail.com

Study Locations

• Turkey (Türkiye)
  • Nilüfer
    • Bursa, Nilüfer, Turkey (Türkiye), 16100
      • Recruiting
      • Bursa City Hospital
      • Contact: Yusuf Alan, MD; Phone Number: 05396210977; Email: dryusufalan@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Female patients aged 18-75 years
• ASA physical status I-III
• Scheduled for elective unilateral modified radical mastectomy with axillary dissection under general anesthesia
• Provision of written informed consent

Exclusion Criteria:

• Anticoagulant therapy
• Bleeding diathesis
• Known allergy to local anesthetics or opioids
• Infection at the block application site or previous surgery in the block area
• Cognitive impairment preventing NRS assessment
• Pregnancy or lactation
• Chronic opioid use
• Severe hepatic or renal failure
• Refusal to participate in the study
• Technical inability to perform the block or failed block

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: RISS Block; Patients will receive an ultrasound-guided rhomboid intercostal-subserratus plane (RISS) block before modified radical mastectomy for postoperative analgesia.	Procedure: Rhomboid Intercostal-Subserratus Plane Block; Ultrasound-guided rhomboid intercostal-subserratus plane block performed before modified radical mastectomy for postoperative analgesia.
Experimental: SPSIP Block; Patients will receive an ultrasound-guided serratus posterior superior intercostal plane (SPSIP) block before modified radical mastectomy for postoperative analgesia.	Procedure: Serratus Posterior Superior Intercostal Plane Block; Ultrasound-guided serratus posterior superior intercostal plane block performed before modified radical mastectomy for postoperative analgesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Postoperative Opioid Consumption	Total opioid consumption during the first 24 hours after modified radical mastectomy.	24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative Remifentanil Consumption	Total intraoperative remifentanil consumption will be recorded and compared between groups.	During surgery
Postoperative Pain Scores	Postoperative pain intensity measured using the Numeric Rating Scale (NRS), ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate worse pain.	0-24 hours after surgery
Compartmental Pain Scores Using Numeric Rating Scale	Numeric Rating Scale (NRS) score (0-10 points) measured separately for axillary pain, anterolateral chest wall pain, and surgical drain insertion site pain. A score of 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate greater pain intensity.	0-24 hours after surgery
Dermatomal Sensory Block Distribution	Number of dermatomes blocked, assessed by pinprick sensory testing 30 minutes after block performance. Higher values indicate wider sensory block distribution.	30 minutes after block performance
Quality of Recovery-15 Score	Quality of Recovery-15 (QoR-15) questionnaire score ranging from 0 to 150, where higher scores indicate better postoperative recovery and patient satisfaction.	24 hours after surgery
Block- and Opioid-Related Complications	Complications related to block performance and opioid use will be recorded.	24 hours after surgery

Collaborators and Investigators

• Sponsor: Ferit Yetik
• Collaborators: Bursa City Hospital
• Investigators: Principal Investigator: Mürsel Ekinci, MD, Bursa City Hospital; Study Chair: Yusuf Alan, MD, Bursa City Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 19, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: June 12, 2026
• First Submitted That Met QC Criteria: June 17, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 24, 2026
• Last Update Submitted That Met QC Criteria: June 19, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Postoperative Pain; Breast Neoplasms; Anesthesia, Conduction
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Signs and Symptoms; Pain, Postoperative; Breast Neoplasms
• Other Study ID Numbers: MRM-2025-KAEK47; 2025-KAEK-47 (Other Identifier: Clinical Research Ethics Committee of University of Health Sciences Bursa Faculty of Medicine)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No