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Completed Not applicable Interventional Results available

Cryoanalgesia to Treat Post-Amputation Phantom Limb Pain: A Department of Defense Funded Multicenter Study

ClinicalTrials.gov ID: NCT03449667

Public ClinicalTrials.gov record NCT03449667. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 5, 2026, 9:17 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

Cryoanalgesia to Treat Post-Amputation Phantom Limb Pain: A Multicenter, Randomized, Double-Masked, Placebo-Controlled, Definitive Human Subjects Clinical Trial

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

When a limb is severed, pain perceived in the part of the body that no longer exists often develops and is called "phantom limb" pain. Unfortunately, phantom pain goes away in only 16% of afflicted individuals, and there is currently no reliable definitive treatment. The exact reason that phantom limb pain occurs is unclear, but when a nerve is cut-as happens with an amputation-changes occur in the brain and spinal cord that actually increase with worsening phantom pain. These abnormal changes may often be corrected by putting local anesthetic-called a "nerve block"-on the injured nerve, effectively keeping any "bad signals" from reaching the brain with a simultaneous resolution of the phantom limb pain. However, when the nerve block resolves after a few hours, the phantom pain returns. But, this demonstrates that the brain abnormalities-and phantom pain-that occur with an amputation are not necessarily fixed, and may be dependent upon the "bad" signals being sent from the injured nerve(s), suggesting that a very long peripheral nerve block-lasting many months rather than hours-may permanently reverse the abnormal changes in the brain, and provide definitive relief from phantom pain. A prolonged nerve block lasting a few months may be provided by freezing the nerve using a process called "cryoneurolysis". The ultimate objective of the proposed research study is to determine if cryoanalgesia is an effective treatment for intractable post-amputation phantom limb pain. The proposed research study will include subjects with an existing lower extremity amputation who experience intractable daily phantom limb pain. A single ultrasound-guided treatment of cryoneurolysis (or sham block-determined randomly like a flip of a coin) will be applied to the target nerve(s) involved with the phantom pain. Although not required, each subject may return four months later for the alternative treatment (if the first treatment is sham, then the second treatment would be cryoneurolysis) so that all participants have the option of receiving the active treatment. Subjects will be followed for a total of 12 months with data collected by telephone.

Study identification

NCT ID
NCT03449667
Recruitment status
Completed
Study type
Interventional
Phase
Not applicable
Enrollment
144 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Mar 22, 2018
Primary completion
Aug 16, 2021
Completion
Mar 16, 2022
Last update posted
Feb 16, 2023

2018 – 2022

United States locations

U.S. sites
6
U.S. states
4
U.S. cities
5
Facility City State ZIP Site status
Veterans Affairs Palo Alto Health Care System Palo Alto California 94304
University California San Diego San Diego California 92103
Naval Medical Center San Diego (NMCSD) San Diego California 92134
University of Florida Gainesville Florida 32610
Walter Reed National Military Medical Center Bethesda Maryland 20889
Cleveland Clinic Cleveland Ohio 44195

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT03449667, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Feb 16, 2023 · Synced Sep 5, 2026

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The complete protocol, eligibility criteria, and contact information for NCT03449667 live on ClinicalTrials.gov.

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