Comparison of US-Guided Paravertebral and Proximal Intercostal Nerve Blocks

November 21, 2025 updated by: Kamen Vlassakov, Brigham and Women's Hospital

A Prospective, Randomized Comparison Between the Ultrasound Guided Paravertebral Block and the Ultrasound Guided Proximal Intercostal Nerve Block

The purpose of this study is to compare the proximal intercostal block to the more medial (classic) ultrasound-guided paravertebral block. The investigators hypothesize that the proximal intercostal block will allow for improved needle visualization, shorter block time, and improved safety profile compared to the classic paravertebral bock.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Although previous studies have made advances towards applying ultrasound guidance to the performance of paravertebral blocks (PVB), a technique combining both safety and technical ease remains elusive. The ideal technique (1) permits continuous visualization of the entire needle shaft and tip, (2) avoids aiming the needle tip and injectate directly toward the neuraxis or lung, and (3) is easy to perform. Visualization of all structures by ultrasound is essential to minimize the risk of vascular puncture, nerve root or spinal cord injury, and pneumothorax. Failure to consistently and quickly identify the transverse process and pleura, as occurs when using older techniques, results in several needle redirections, causing pain and discomfort to patients, and increases the potential risk of pneumothorax. The technical difficulty of applying previously-described US-guided techniques takes an inordinate amount of time and is clinically less practical within a busy surgical practice.

In the current study, the investigators describe a novel, modified approach to real-time ultrasound-guided single shot paravertebral blockade, the proximal intercostal block (PICB), which utilizes a sagittal paramedian US probe placement to identify the intercostal space and PVS. In this method, instead of placing the probe at a fixed traditional distance of 2.5 cm from the spinous processes, the probe is moved laterally to obtain a comprehensive image, with a clear view of the ribs, internal intercostal membrane, and the parietal pleura.

The investigators propose that moving the probe laterally towards the proximal intercostal space allows clearer simultaneous visualization of both pleura and needle as it advances towards the PVS, while achieving comparable injectate spread and, ultimately, similar or better clinical results. Such improved visualization will reduce the number of needle passes, increase confidence in the user, decrease block placement time, and improve overall block success. This technique combines the advantages of more lateral approaches (better visualization of structures, in particular the pleura) with the advantage of the more medial approaches (in-plane, closer, and not directed at the neuraxis).

Study Type

Interventional

Enrollment (Actual)

20

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 Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham and Women's Hospital

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

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Females age 18-85 years old
  2. ASA 1-3
  3. Patient scheduled for unilateral or bilateral mastectomy with or without reconstruction

Exclusion Criteria:

  1. Coagulopathy
  2. Patient refusal
  3. Allergy to local anesthetics

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Proximal Intercostal Block
See Intervention Section
Procedure: Proximal Intercostal Block
After identifying the correct intercostal space, the ultrasound probe will be moved medially to identify the transverse processes, then again laterally from the transverse processes to rest over the ribs so as to obtain the best view of ribs and pleura. A 10cm, 21G needle will be inserted in-plane at the caudal border of the probe. An attempt will be made to keep the needle tip and the target injection position (just under the internal intercostal membrane (IIM)) in view. Correct needle tip placement will be demonstrated by depression of the pleura/endothoracic fascia upon local anesthetic injection and by lack of retrograde spread of LA over the muscles or the ribs. The LA will be injected in 4 cc aliquots after negative aspiration of air, CSF and blood.
Other Names:
  • PICB
Active Comparator: Paravertebral Block
See Intervention Section
Procedure: Paravertebral Block
After identifying the correct intercostal space, the ultrasound probe will be placed between the adjacent transverse processes in a longitudinal/parasagittal plane measuring 2.5cm from the midline. The best possible view of the transverse processes, the superior costotransverse ligament and pleura will be obtained. An attempt will be made to keep the needle tip and the target injection position (immediately beneath the costotransverse ligament) in view. Correct placement of the needle tip will be demonstrated by depression of the pleura upon injection of local anesthetic and by lack of retrograde spread of LA over the muscles or transverse processes. The LA will be injected in 4 cc aliquots after confirming negative aspiration of air, CSF and blood.
Other Names:
  • PVB

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ultrasound Image Quality Score
Time Frame: Evaluated at time of block

The following will be assessed for each image and video, and saved during each block performed:

  1. Best possible image of block anatomy (including the pleura, transverse process/rib, costotransverse ligament/internal intercostal membrane, as appropriate) as well as needle location.
  2. Video of the space during injection, reflecting the injectate spread. The images will be rated by a separate regional anesthesiologist not involved in study, but proficient with both types of blocks and ultrasound imaging.
  3. The following score 3 point scale will be used to rate visibility: 0=not visible, 1=hardly visible, 2=well visible, 3=very well visible. Maximum score possible=18 including both pieces of media.
Evaluated at time of block

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Block Performance Time
Time Frame: Evaluated at time of block
Defined as the sum of imaging and needling times
Evaluated at time of block
Imaging Time
Time Frame: Established during block performance
Defined as the time interval between contact of the ultrasound probe with the patient, and the acquisition of a satisfactory image (which will be saved and analyzed later by a regional anesthesiologist blinded to the particular aims of the study).
Established during block performance
Needling Time
Time Frame: Established during block performance
Defined as the time interval between the start of the skin wheal and the end of local anesthetic injection through the block needle.
Established during block performance
Number of Needle Passes
Time Frame: Established during block performance
Initial needle insertion will be counted as "first pass". Any subsequent needle advancement, preceded by a retraction of more than 2 cm, will be counted as an additional pass.
Established during block performance
Distance of Injection Sites from Midline
Time Frame: Established during block performance
Measured and recorded (one of our clinical aims)
Established during block performance
Presence of Perioperative Block-Related Complications
Time Frame: Within 24 hours of block placement

The presence of the following complications will be recorded:

  1. Horner's syndrome
  2. Pneumothorax
  3. Local anesthetic systemic toxicity (LAST)
  4. Pain on injection
  5. Evidence of contralateral block (for unilateral procedures)
Within 24 hours of block placement
Effectiveness of the Block
Time Frame: One hour following extubation, and at 24 hours following block placement
Patients will be asked to provide a verbal rating score of pain (0-10) at two time points: one hour following extubation, and 24h following block placement. At the 1 hour following extubation time point, we will be checking the coverage of the block in terms of dermatomal spread (see below).
One hour following extubation, and at 24 hours following block placement
Dermatomal spread
Time Frame: One hour following extubation
Number of dermatomal block levels, determined by loss of sensation to cold (ice) or to loss of pinprick sensation in the PACU one hour after extubation.
One hour following extubation
Opioid requirement
Time Frame: Evaluated at 1 hour after extubation, and then at 24 hours following the block
Opioid requirement, including intraoperative, PACU, and during the entire hospital admission, normalized to morphine equivalents.
Evaluated at 1 hour after extubation, and then at 24 hours following the block
Prolonged postoperative pain
Time Frame: 6 and 12 months after surgery
Postoperative contact via secure e-mail at will assess for the incidence of chronic pain.
6 and 12 months after surgery

Collaborators and Investigators

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

Sponsor

Brigham and Women's Hospital

Investigators

  • Principal Investigator: Kamen Vlassakov, MD, Brigham and Women's Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Actual)

September 9, 2016

Primary Completion (Actual)

July 13, 2017

Study Completion (Actual)

January 7, 2020

Study Registration Dates

First Submitted

August 12, 2016

First Submitted That Met QC Criteria

September 20, 2016

First Posted (Estimated)

September 22, 2016

Study Record Updates

Last Update Posted (Estimated)

November 25, 2025

Last Update Submitted That Met QC Criteria

November 21, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2016P000174/MGH

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

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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