Post-Mastectomy Chronic Pain SyndromeRPNINCT04530526
Surgical Treatment of Post-surgical Mastectomy Pain Utilizing the Regenerative Peripheral Nerve Interface
A study testing Regenerative Peripheral Nerve Interface in people with Post-Mastectomy Chronic Pain Syndrome, run by University of Michigan Rogel Cancer Center at 1 site in United States.
Trial summary
Post-mastectomy pain due to nerve injury leads to long-term opioid use and diminished quality-of-life. The investigators on this study will evaluate the regenerative peripheral nerve interface (RPNI), a novel surgical approach to neuroma treatment, to improve patient-reported post-mastectomy pain and definitively… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Post-Mastectomy Chronic Pain Syndrome
- What is being tested?
- Regenerative Peripheral Nerve Interface
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 26 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Jul 2019to 30 Sep 2023
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- In order to be eligible to participate in this study, a subject must meet all of the following criteria:
- Reporting post-mastectomy pain at least six months removed from mastectomy or partial mastectomy (lumpectomy).
- Willing to comply with all study procedures and be available for the duration of the study
- Fluent in English
- Women of reproductive potential must use highly effective contraception (specify methods of contraception acceptable for the study, e.g., licensed hormonal methods) and/or willingness to undergo a pregnancy test.
Who cannot join
- A potential subject who meets any of the following criteria will be excluded from participation in this study:
- Previous surgical management for chronic post-mastectomy pain
- Signs/symptoms which are not suggestive of neuropathic pain based on physical exam at time of consultation.
- Pregnancy or lactation
- Men will not be enrolled in this study due to the low prevalence of male mastectomy.
- Anything that, in the opinion of the investigator, would place the subject at increased risk or preclude the subject's full compliance with or completion of the study.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Michigan Rogel Cancer Center
Ann Arbor, Michigan, 48109
About this study
Official title: Surgical Treatment of Post-surgical Mastectomy Pain Utilizing the Regenerative Peripheral Nerve Interface (RPNI)
Post-mastectomy pain due to nerve injury leads to long-term opioid use and diminished quality-of-life. The investigators on this study will evaluate the regenerative peripheral nerve interface (RPNI), a novel surgical approach to neuroma treatment, to improve patient-reported post-mastectomy pain and definitively treat intercostal neuromas after mastectomy.
Read the detailed description
Up to 40% of patients who undergo mastectomy suffer from chronic pain, defined as pain lasting greater than three months. Chronic post-mastectomy pain due to nerve injury leads to long-term opioid use and diminished quality-of-life. A novel surgical approach to neuroma treatment, the regenerative peripheral nerve interface (RPNI) developed to treat painful neuromas associated with limb amputation has shown significant reductions in patient-reported pain. RPNI surgery is now available through Michigan Medicine's Multi-Disciplinary Peripheral Nerve (MDPN) Clinic to improve post-mastectomy pain and definitively treat intercostal neuromas following mastectomy. Using patient-reported outcomes and clinical data the investigators will evaluate the use of RPNI surgery to reduce persistent post- mastectomy pain in women seeking surgical consultation through the Plastic Surgery or MDPN clinics.
- Conditions
- Post-Mastectomy Chronic Pain Syndrome
- Being tested
- Regenerative Peripheral Nerve Interface
- Keywords
- neuroma,outcome-assessment health care, post-mastectomy, outcome-assessment health care, post-mastectomy, neuroma
- Medical subject headings
- Neuroma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Regenerative Peripheral Nerve InterfaceProcedure or surgery
The regenerative peripheral nerve interface (RPNI) has emerged as a novel strategy to treat neuromas in peripheral nerves. The RPNI consists of the residual peripheral nerve end implanted in a skeletal muscle graft, following surgical resection of the injured terminal nerve portion (neuroma). The free muscle graft is separated from its native nerve innervation, leaving open neuromuscular junctions for ingrowth and attachment of nerve fibers from the implanted nerve.
| Study group | Role | What they receive |
|---|---|---|
| Regenerative Peripheral Nerve Interface (RPNI) | Other | Using evaluative ultrasound measurements and a standard panel of patient-reported outcome measures (PROMs) to measure pain experience, anxiety and depression, patients will be evaluated at baseline (T1=0months), pre-operatively following 3 months of standard neuropathic pain management therapy (T2=3months) and at three months (T3=6months) and nine months (T4=12months) post RPNI surgery. Receives: Procedure: Regenerative Peripheral Nerve Interface |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Pain Level
The use of RPNI surgery to reduce post-mastectomy pain will be evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Numerical Pain Rating Scale (0-10)- 10 indicating more pain Short Form McGill Pain Questionnaire 2 (0-10)- 10 indicating more pain Pain Catastrophizing Score (0-52)- 52 indicating more pain PROMIS Intensity (0-12)- 12 indicating more pain PROMIS Interference (0-24)- 24 indicating more pain PROMIS Neuropathic (0-20)- 20 indicating more pain
Measured: baseline, and 9 months post surgery
Change in Depression/Anxiety Scores
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Patient Health Questionnaire-9 range is 0-27. 27 indicates a worse outcome. Generalized Anxiety Disorder-7 range is 0-21. 21 indicates a worse outcome.
Measured: baseline, and 9 months post surgery
Change in Opioid Consumption (Number of Opioid Medications)
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Measured: baseline, and 9 months post surgery
Freedom From Neuroma Recurrence Evaluated by Physical Exam
Data will be derived from standard clinical care for patients seeking surgical management of post-mastectomy chronic pain. Physical examinations will be performed at the time of patient enrollment and subsequent follow-up visits, as part of routine clinical evaluation, up to approximately 9 months after RPNI surgery. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Measured: 24 months post enrollment
Freedom From Neuroma Recurrence Evaluated by Ultrasound
Data will be derived from standard clinical care for patients seeking surgical management of post-mastectomy chronic pain. Ultrasound will be performed at the time of patient enrollment and subsequent follow-up visits, as part of routine clinical evaluation, up to approximately 9 months after RPNI surgery. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Measured: 24 months post enrollment
Change in Opioid Consumption (Oral Morphine Equivalents)
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Measured: baseline, and 9 months post surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Aug 2020
- Study start12 Jul 2019
- Primary completion30 Jun 2023
- Study completion30 Sep 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Post-Mastectomy Chronic Pain SyndromeStudies of the same condition, open and under way.
- More trials run by University of Michigan Rogel Cancer CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Michigan Rogel Cancer Center
- Sponsor type
- University, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Responsible party
- Sponsor
- Investigators
- David L Brown, M.D., Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04530526
- Sponsor's protocol ID
- UMCC 2018.124
- Other IDs
- HUM00149189, R21CA234760
- Acronym
- RPNI
- Status last verified
- Dec 2025
- First submitted
- 24 Aug 2020
- Last updated
- 24 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Nag S, Kennedy P, Aris K, Moore AM, Farhadi R. The Role of Nerve Surgery in the Management of Post-Breast Surgery Pain Syndrome: A Systematic Review and Meta-analysis. Ann Plast Surg. 2025 Dec 1;95(6):625-629. doi: 10.1097/SAP.0000000000004516. Epub 2025 Oct 16.
PubMed 41133892
Study at a glance
From the registry record, last updated by the sponsor on 24 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Surgical Treatment of Post-surgical Mastectomy Pain Utilizing the Regenerative Peripheral Nerve Interface (RPNI)
- ClinicalTrials.gov ID
- NCT04530526
- Acronym / sponsor ID
- RPNI / UMCC 2018.124
- Conditions
- Post-Mastectomy Chronic Pain Syndrome
- Keywords
- neuroma,outcome-assessment health care, post-mastectomy, outcome-assessment health care, post-mastectomy, neuroma
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- University of Michigan Rogel Cancer CenterUniversity, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Study start
- 12 Jul 2019 (actual)
- Primary completion
- 30 Jun 2023 (actual)
- Study completion
- 30 Sep 2023 (actual)
- First posted
- 28 Aug 2020 (actual)
- Results
- Posted 24 Dec 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Post-mastectomy pain due to nerve injury leads to long-term opioid use and diminished quality-of-life. The investigators on this study will evaluate the regenerative peripheral nerve interface (RPNI), a novel surgical approach to neuroma treatment, to improve patient-reported post-mastectomy pain and definitively treat intercostal neuromas after mastectomy.
Detailed description
Up to 40% of patients who undergo mastectomy suffer from chronic pain, defined as pain lasting greater than three months. Chronic post-mastectomy pain due to nerve injury leads to long-term opioid use and diminished quality-of-life. A novel surgical approach to neuroma treatment, the regenerative peripheral nerve interface (RPNI) developed to treat painful neuromas associated with limb amputation has shown significant reductions in patient-reported pain. RPNI surgery is now available through Michigan Medicine's Multi-Disciplinary Peripheral Nerve (MDPN) Clinic to improve post-mastectomy pain and definitively treat intercostal neuromas following mastectomy. Using patient-reported outcomes and clinical data the investigators will evaluate the use of RPNI surgery to reduce persistent post- mastectomy pain in women seeking surgical consultation through the Plastic Surgery or MDPN clinics.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Regenerative Peripheral Nerve Interface (RPNI) | Other | Procedure: Regenerative Peripheral Nerve InterfaceUsing evaluative ultrasound measurements and a standard panel of patient-reported outcome measures (PROMs) to measure pain experience, anxiety and depression, patients will be evaluated at baseline (T1=0months), pre-operatively following 3 months of standard neuropathic pain management therapy (T2=3months) and at three months (T3=6months) and nine months (T4=12months) post RPNI surgery. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- In order to be eligible to participate in this study, a subject must meet all of the following criteria:
- Reporting post-mastectomy pain at least six months removed from mastectomy or partial mastectomy (lumpectomy).
- Willing to comply with all study procedures and be available for the duration of the study
- Fluent in English
- Women of reproductive potential must use highly effective contraception (specify methods of contraception acceptable for the study, e.g., licensed hormonal methods) and/or willingness to undergo a pregnancy test.
Key exclusion criteria (6 listed)
- A potential subject who meets any of the following criteria will be excluded from participation in this study:
- Previous surgical management for chronic post-mastectomy pain
- Signs/symptoms which are not suggestive of neuropathic pain based on physical exam at time of consultation.
- Pregnancy or lactation
- Men will not be enrolled in this study due to the low prevalence of male mastectomy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Regenerative Peripheral Nerve InterfaceThe regenerative peripheral nerve interface (RPNI) has emerged as a novel strategy to treat neuromas in peripheral nerves. The RPNI consists of the residual peripheral nerve end implanted in a skeletal muscle graft, following surgical resection of the injured terminal nerve portion (neuroma). The free muscle graft is separated from its native nerve innervation, leaving open neuromuscular junctions for ingrowth and attachment of nerve fibers from the implanted nerve. | Procedure or surgery | Regenerative Peripheral Nerve Interface (RPNI) |
Primary outcome
Change in Pain Level
Time frame: baseline, and 9 months post surgery
The use of RPNI surgery to reduce post-mastectomy pain will be evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops. Numerical Pain Rating Scale (0-10)- 10 indicating more pain Short Form McGill Pain Questionnaire 2 (0-10)- 10 indicating more pain Pain Catastrophizing Score (0-52)- 52 indicating more pain PROMIS Intensity (0-12)- 12 indicating more pain PROMIS Interference (0-24)- 24 indicating more pain PROMIS Neuropathic (0-20)- 20 indicating more pain
Change in Depression/Anxiety Scores
Time frame: baseline, and 9 months post surgery
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops. Patient Health Questionnaire-9 range is 0-27. 27 indicates a worse outcome. Generalized Anxiety Disorder-7 range is 0-21. 21 indicates a worse outcome.
Change in Opioid Consumption (Number of Opioid Medications)
Time frame: baseline, and 9 months post surgery
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Freedom From Neuroma Recurrence Evaluated by Physical Exam
Time frame: 24 months post enrollment
Data will be derived from standard clinical care for patients seeking surgical management of post-mastectomy chronic pain. Physical examinations will be performed at the time of patient enrollment and subsequent follow-up visits, as part of routine clinical evaluation, up to approximately 9 months after RPNI surgery. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Freedom From Neuroma Recurrence Evaluated by Ultrasound
Time frame: 24 months post enrollment
Data will be derived from standard clinical care for patients seeking surgical management of post-mastectomy chronic pain. Ultrasound will be performed at the time of patient enrollment and subsequent follow-up visits, as part of routine clinical evaluation, up to approximately 9 months after RPNI surgery. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Change in Opioid Consumption (Oral Morphine Equivalents)
Time frame: baseline, and 9 months post surgery
Evaluated by validated patient-reported outcome (PRO) surveys administered at 4 timepoints: at baseline (at time of enrollment), at the RPNI pre-operative visit (approximately 3 months after enrollment), and at approximately 3 and 9 months after RPNI surgery. The average time of study involvement for each patient will be 12 months. Patients enrolled during the first year of the study's 2-year recruitment period may be followed until the study stops.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 41133892Nag S, Kennedy P, Aris K, Moore AM, Farhadi R. The Role of Nerve Surgery in the Management of Post-Breast Surgery Pain Syndrome: A Systematic Review and Meta-analysis. Ann Plast Surg. 2025 Dec 1;95(6):625-629. doi: 10.1097/SAP.0000000000004516. Epub 2025 Oct 16.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David L Brown, M.D. principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Regenerative Peripheral Nerve Interface in people with Post-Mastectomy Chronic Pain Syndrome, run by University of Michigan Rogel Cancer Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 24 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Pain Level (time frame: baseline, and 9 months post surgery). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04530526, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Dec 2025.