A sham-controlled randomised trial of Tecar therapy for painful caesarean scars: the NOCEPAIN study protocol.

Introduction: Caesarean section is a frequent procedure in obstetrics, accounting for 21.4% of deliveries in France in 2021. Three months after delivery, 15.4% of these women report they still have pain, which can be associated with psychological disorders (including anxiety and depression). Although the only treatment currently recommended is self-massage of the scar, capacitive and resistive electric transfer (Tecar) therapy could improve healing and reduce pain associated with caesarean scars and, therefore, improve women's health-related quality of life (QoL). We aim to evaluate the analgesic efficacy of Tecar therapy for postoperative scar pain and/or discomfort at 3 months postpartum by comparing it with sham Tecar therapy.

Methods and analysis: The NOCEPAIN study is a two-centre, single-blind, two-arm, parallel-group, sham-controlled randomised trial currently underway. A total of 120 women with a caesarean scar still painful at 6-8 weeks postpartum, aged 18-50 years, are being randomly allocated in a ratio of 1:1 to either the active Tecar therapy group (active device group) or the sham Tecar therapy group (placebo device group). The women undergo one Tecar or sham session of 20 min per week for 3 weeks. Women in both groups also receive the recommended standard treatment: manual self-massage of the scar.The primary outcome is the caesarean scar pain and/or discomfort at 3 months postpartum, assessed with a Visual Analogue Scale from 0 (no pain and/or discomfort) to 10 (the worst imaginable). Secondary outcomes include validated self-report questionnaires about pain (French adaptations of the McGill Pain Questionnaire and the Brief Pain Inventory, as well as the 'Douleur Neuropathique en 4 Questions' instrument for neuropathic pain), the interference of pain with activities of daily living (Multidimensional Pain Inventory), anxiety and depression (Hospital Anxiety and Depression Scale), health-related QoL (WHO QoL Brief) and sexual functioning (Female Sexual Function Index). The final secondary outcomes are the quality of skin healing (Vancouver Scar Scale), as well as analgesic use and concomitant treatments for analgesia.

Ethics and dissemination: The West III Committee for the Protection of Persons (French Institutional Review Board) approved this study and its compliance with French individual data protection laws (number: 2022-A01492-41, 20 March 2023). All participants provide written informed consent before randomisation. The results will be reported in peer-reviewed journals and at scientific meetings.

Trial registration number: NCT05696301.