However , intercostal nerve injury seems to be the most important pathogenic factor .
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 systematic s 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 .
Pain management and spirometry following thoracotomy: a prospective, randomized study of four techniques.
Forty-five patients who underwent anterolateral and posterolateral thoracotomy  were studied to compare the relative efficacy of cryoanalgesia , epidural morphine , intrapleural analgesia , and intravenous morphine for relief of postoperative pain and prevention of deterioration in pulmonary function . Spirometry ( FEV1 , FVC ) was performed preoperatively and postoperatively . Patients '  pain was assessed using the 0 to 100 mm visual analog scale . Because intravenous morphine was used to supplement pain relief in the patients who received intrapleural analgesia and cryoanalgesia , total morphine use was compared to that administered to patients in the intravenous morphine group . Epidural morphine was found to offer better pain relief than the other treatment modalities . There were no differences in spirometric testing between the groups at any time during the study . Although the number of evaluable patients was insufficient to draw definitive conclusions , 12-week follow-up suggested a difference in the incidence of post-thoracotomy pain syndrome in patients who received cryoanalgesia . It is concluded that post-thoracotomy pain is best relieved with epidural morphine , compared to intrapleural analgesia , cryoanalgesia , and parenteral morphine . There was no change in the deterioration in spirometric tests after thoracotomy , nor was there any advantage offered by cryoanalgesia or intrapleural analgesia over intravenous morphine , with respect to pain relief
However , intercostal nerve injury seems to be the most important pathogenic factor .
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 systematic s 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 .