Serratus Plane Block (SPB) Versus Capsaïcine Versus Botox-A for Chronic Neuropathic Pain in Post-mastectomy Syndrome
Centre Oscar Lambret
123 participants
Mar 31, 2026
INTERVENTIONAL
Conditions
Summary
The goal of this phase II clinical trial is to study the effectiveness of a treatment with Serratus Plane Block (SPB) or Botox-A in comparison with capsaicin for the control of chronic neuropathic pain of post-mastectomy syndrom, that is not adequately managed by systemic treatment alone. The primary outcome will be the pain evaluation at 8 weeks. 123 patients with chronic neuropathic pain of post-mastectomy syndrom insufficiently relieved by systemic treatment alone will be recruited over 24 months at the Centre Oscar Lambret. Patients will be randomly assigned to one of three treatment groups (41 patients per group): Capsaicin Botulinum toxin A SPB Patients will be followed for 24 weeks after the study treatment. The follow-up will include remote evaluation and 2 medical visits during which pain and quality of life will be assessed.
Eligibility
Inclusion Criteria12
- Women aged ≥ 18 years;
- Unilateral breast cancer treated by total or partial mastectomy:
- with sentinel lymph node technique (SLN) or axillary dissection;
- with or without immediate reconstruction using a prosthesis;
- associated or not with radiotherapy and/or chemotherapy;
- Presenting moderate to severe chronic neuropathic pain, defined by:
- Numerical Pain Scale (NPS) ≥ 3 and DN4 ≥ 4,
- on a localised aera ((≤ 240 cm²), at the surgical site, in the axillary hollow, or on the inner side of the ipsilateral arm,
- between 3 and 9 months after breast surgery,
- with indication of additional locoregional treatment in complement to a systemic treatment of chronic neuropathic pain, as recommended by the SFETD - French Society for the Study and Treatment of Pain (tricyclic antidepressants or IRSNA or gabapentinoid PLUS lidocaine patch, at the appropriate dosage) and implemented for at least 4 weeks;
- Patient affiliated with a health insurance plan;
- Patient informed and having consented to participate in the trial.
Exclusion Criteria32
- Ipsilateral breast cancer recurrence, regardless of the first treatment;
- History of breast or thoracic surgery prior to mastectomy with residual pain;
- Painful polyneuropathy related to chemotherapy requiring treatment;
- Ongoing or planned loco-regional adjuvant radiotherapy within the next 8 weeks;
- Treatment area not suitable for potential botulinum toxin type A treatment;
- Breast reconstruction using flap or lipomodelling;
- Indication for breast reconstruction within the next 8 weeks;
- Chronic pain of another etiology such as:
- Neuropathic pain secondary to a neuroma (localized pain),
- Radiodermatitis,
- Phantom breast pain,
- Lymphedema,
- Complex regional pain syndrome,
- Adhesive capsulitis,
- Fibromyalgia;
- Hypersensitivity or allergy to anesthetics, capsaicin, naropein, clonidine hydrochloride, an amide-type local anesthetic, botulinum toxin type A, or any excipient contained in the preparations;
- Infection or inflammation at the injection site;
- Therapeutic/effective anticoagulation;
- Clinical signs or medical history leading to the diagnosis of:
- Hemostasis disorder,
- Local infection,
- Severe renal insufficiency (creatinine clearance \< 30 mL/min),
- Thrombocytopenia \< 50,000 platelets/mm3;
- Generalized muscle activity disorders (e.g., myasthenia, Lambert-Eaton syndrome);
- Heart rate lower than 60/minute;
- Severe bradyarrhythmia due to sick sinus syndrome or second or third-degree atrioventricular block;
- State of depression (HADS score ≥ 11);
- Other contraindication to any of the study treatments;
- Inability for the patient to follow the study schedule;
- Inability for the patient or the healthcare team to perform the treatment within 2 weeks;
- Pregnant or breastfeeding women, women who are able to conceive and who do not use a highly effective method of contraception during the trial and for at least 1 month after the end of treatment ;
- Patient under guardianship or curatorship.
Interventions
One or two capsaicin patch (8%) are applied for 60 minutes to the site of neuropathic pain, in day-hospital. An oral, antalgic pre-medication may be done with one of the following medications (alone or association): paracetamol 1g, nefopam 30 mg, tramadol 100 mg, morphine 10mg, oxycodone 5mg. Capsaicin will be administered in addition to a systemic treatment that has been ongoing for at least 4 weeks. If pain persists, the capsaicin patch application may be repeated at 12 weeks.
The Serratus Plane Block (SPB) is a nerve block performed by a trained anesthesiologist to provide localized pain relief. It involves the injection of a local anesthetic: Maximum 150 mg naropeine combined with 150 μg clonidine hydrochloride into the serratus anterior plane under ultrasound guidance. An anesthesiologist will perform the procedure in a post-interventional recovery room, with light sedation.The SBP will be carried out in addition to a systemic treatment that has been ongoing for at least 4 weeks. The SPB may be repeated every two weeks up to four times in the initial 8-week period, with an additional repeat at 12 weeks if pain control remains insufficient.
Botulinum Toxin A (Botox-A) is injected into the affected area, with a total of 300 units administered across up to 60 injection sites. An anesthesiologist will perform the procedure in a post-interventional recovery room, with light sedation. This intervention will be carried out in addition to a systemic treatment that has been ongoing for at least 4 weeks, and is aimed at providing prolonged pain relief for post-mastectomy neuropathic pain. Light sedation is provided, and injections may be repeated at 12 weeks if necessary.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06807164