Chronic post-thoracotomy pain: a critical review of pathogenic mechanisms and strategies for prevention.

Chronic pain complaints after thoracic surgery represent a significant clinical problem in 25-60% of patients. Results from thoracic and other surgical procedures suggest multiple pathogenic mechanisms that include pre-, intra-, and postoperative factors. This review attempts to analyse the methodology and systematics of the studies on the post-thoracotomy pain syndrome (PTPS) after lung cancer surgery in adults, in order to clarify the relative role of possible pathogenic factors and to define future strategies for prevention. Literature published from 2000 to 2008 together with studies included in previous systematic reviews was searched recursively using PubMed and OVID by combining three categories of search terms. The available data have major inconsistencies in collection of pre-, intra- and postoperative data that may influence PTPS, thereby hindering precise conclusions as well as preventive and treatment strategies. However, intercostal nerve injury seems to be the most important pathogenic factor. Since there is a general agreement on the clinical relevance of PTPS, a proposal for design of future trials is presented.