Intercostal Cryoanalgesia Versus Thoracic Epidural Analgesia for Postoperative Pain Control After Thoracic Surgery: Study Protocol for a Randomized Clinical Trial.

Background: Post-thoracic surgery pain remains a major clinical challenge, with substantial impact on pulmonary function, postoperative recovery, and patient quality of life. Thoracic epidural analgesia is widely regarded as the standard of care; however, it is associated with potential complications, including hypotension, urinary retention, and inadequate analgesia in a subset of patients. Intercostal cryoanalgesia, a peripheral nerve block technique that induces temporary axonal degeneration through controlled freezing, has emerged as a potential alternative for prolonged postoperative pain control. Objective: The primary objective of this study is to compare postoperative hospital length of stay between intercostal cryoanalgesia and thoracic epidural analgesia. Secondary objectives include the evaluation of postoperative pain intensity, opioid consumption, adverse effects, postoperative complications, quality of life, quality of recovery, and patient satisfaction. Methods: This is a single-center, prospective, randomized, parallel-group clinical trial comparing intercostal cryoanalgesia with thoracic epidural analgesia for postoperative pain control in patients undergoing thoracic surgery. Fifty adult patients (≥18 y) are randomized 1:1 to either epidural or cryoanalgesia groups. All perioperative and postoperative care is provided by the attending clinical teams according to routine institutional practice, with no influence from the research team beyond randomized allocation. The primary endpoint is postoperative hospital length of stay. Secondary outcomes include pain intensity (visual analog scale), opioid consumption, incidence of adverse effects and complications, quality of life (WHOQOL-BREF), and quality of recovery (QoR-15). Data are collected up to 1 year postoperatively. Results: Approval from the Human Research Ethics Committee was obtained in November 2024, and participant recruitment began in July 2025. Data collection commenced concurrently with participant recruitment and is expected to be completed by August 28, 2027. Data analysis will begin in September 2027, with results anticipated in the first quarter of 2028. Conclusions: This study protocol outlines a randomized clinical trial designed to assess clinical outcomes associated with intercostal cryoanalgesia compared with thoracic epidural analgesia following thoracic surgery. The findings are expected to contribute to the evidence base on postoperative pain management and inform the design of future comparative and implementation studies in this field.