Transition from acute to chronic pain after surgery.

1. INTRODUCTION : Any tissue trauma can lead to “chronic pain,” which by definition is pain that persists past the normal healing time.40 This type of pain is frequent after surgery. In 1998, Crombie et al.8 noted that 22.5% of patients attending pain clinics attributed their pain to a previous surgery, and since then, numerous original research articles, review articles, and editorials have addressed chronic pain after surgery. Long-term pain after surgery causes disability and suffering associated with reduced quality of life and increased use of health care resources. For that reason, chronic postsurgical pain (CPSP) has become a health priority and will be included in the new version of the International Classification of Diseases (ICD-11), as a result of the combined efforts of the World Health Organization (WHO) and the IASP.40 Adequate pain treatment is a human right, and the inclusion of CPSP in the ICD-11 is expected to increase recognition of the problem and promote interdisciplinary research in the field. Indeed, CPSP is now accepted as an important outcome of surgery. Researchers have determined its prevalence in the adult population and examined its incidence after various procedures. However, while the global volume of surgeries is increasing worldwide,41 the occurrence of CPSP has not really decreased over the years because preventive strategies are not clearly defined and thereby not applied in clinical practice, in contrast to the progress made in basic research in the understanding of incisional pain physiology.10 In daily clinical practice, the transition from acute postoperative pain to CPSP is often subtle and unpredictable. Rather than focusing on pathophysiological mechanisms, the following discussion will address clinical aspects, ongoing improvements in management, and future challenges