NCT04267315

Trigger Point Injections for Post-Mastectomy Pain Syndrome

Trigger Point Injections for Post-Mastectomy Pain Syndrome: A Double-Blind Randomized Controlled Trial With Intention-to-Treat Analysis

• Status: Unknown
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 72 (actual)
• Sponsor: Instituto do Cancer do Estado de São Paulo · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Not accepted

Summary

Post-Mastectomy Pain Syndrome (PMPS) is a chronic pain that persists for more than three months after a surgical breast procedure. It has 11-70% incidence in patients that underwent a breast surgery. It consists of mixed pain, frequently associated with myofascial pain, an specific type of muscular pain. Trigger point injections (TPI) are classically used for the treatment of myofascial pain in other painful conditions. However, there are no controlled trials assessing the efficacy of TPI in the treatment of PMPS. The intervention objective is to assess the efficacy of TPI in patients with PMPS, when associated with a comprehensive rehabilitation program and pain management.

Detailed description

INTRODUCTION: Post-Mastectomy Pain Syndrome (PMPS) is a chronic pain that persists for more than three months after a surgical breast procedure. It has 11-70% incidence in patients that underwent a breast surgery. It consists of mixed pain, frequently associated with myofascial pain. Trigger point injections (TPI) are classically used for the treatment of myofascial pain in other etiologies. However, there are no controlled trials assessing the efficacy of TPI in the treatment of PMPS OBJECTIVE: Assess the efficacy of TPI in patients with PMPS, when associated with a comprehensive rehabilitation program and pain management. METHODS: Double-blind randomized controlled trial with intention-to-treat analysis. Both groups will undergo standard of care delivered by Physiatrist blinded to group allocation. Active group will undergo TPI with 1% lidocaine in each identified trigger-point, weekly, for three consecutive weeks. Control group will undergo subcutaneous saline injection superficial to the same trigger points, with the same frequency and number of sessions. Primary outcome is the mean difference between groups for pain levels, as assessed by Visual Numeric Scale (VNS), from baseline to 3 months after the procedure. STATISTICAL ANALYSIS: Difference between groups at baseline, one and three months after injection, using Analysis of Covariance (ANCOVA) for the following outcomes: VNS; Presence of active trigger points, Pressure pain threshold (PPT); Short-Form McGill Pain Questionnaire (SF-MPQ); Neuropathic Pain Symptom Inventory (NPSI); Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH); Range of motion (ROM) of affected shoulder, for abduction and external rotation; adverse events; use of pain medication. Total sample size is 120. Alpha=5%, power=80%.

Conditions

• Post-mastectomy Pain Syndrome
• Myofascial Pain Syndrome
• Trigger Point Pain, Myofascial
• Breast Cancer

Interventions

Type	Name	Description
PROCEDURE	Trigger point injection	1mL injections of 1% lidocaine in the muscles identified active trigger points at the day of intervention (pectoralis major, serratus anterior, levator scapulae, latissimus dorsi, infraspinatus).
PROCEDURE	Subcutaneous saline injection	0.2mL subcutaneous saline injections superficial to the muscles identified with active trigger points at the day of intervention (pectoralis major, serratus anterior, levator scapulae, latissimus dorsi, infraspinatus).
OTHER	Comprehensive Rehabilitation program	Patients in both groups will undergo standard of care rehabilitation delivered by a Physiatrist, which may include Physical Therapy, Occupational Therapy, Exercise Physiologist, Rehabilitation Nurse, Psychologist, as per Physiatrist's prescription. Both the comprehensive rehabilitation program and pain medications will continue to be managed by participant's Physiatrist, who will be blinded to patient's allocation. The researchers will be responsible for TPI and for data collection.

Timeline

• Start date: 2020-01-03
• Primary completion: 2023-11-30
• Completion: 2024-02-15
• First posted: 2020-02-12
• Last updated: 2023-10-16

Locations

2 sites across 1 country: Brazil