RISS Versus SPSIP Block in Modified Radical Mastectomy (RSMRM)

June 17, 2026 updated by: Ferit Yetik

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

Not yet recruiting

Conditions

Intervention / Treatment

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

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

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
Time Frame: 24 hours after surgery
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
Time Frame: During surgery
Total intraoperative remifentanil consumption will be recorded and compared between groups.
During surgery
Postoperative Pain Scores
Time Frame: 0-24 hours after surgery
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
Time Frame: 0-24 hours after surgery
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
Time Frame: 30 minutes after block performance
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
Time Frame: 24 hours after surgery
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
Time Frame: 24 hours after surgery
Complications related to block performance and opioid use will be recorded.
24 hours after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

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

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 30, 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 22, 2026

Last Update Submitted That Met QC Criteria

June 17, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MRM-2025-KAEK47
  • 2025-KAEK-47 (Other Identifier: Bursa City Hospital Clinical Research Ethics Committee)

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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