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 .
Pre-emptive effect of multimodal analgesia in thoracic surgery.
Thirty subjects undergoing posterolateral thoracotomy were allocated r and omly to receive one of two analgesic regimens : group Pre received i.v . morphine , i.m . diclofenac and intercostal nerve blocks from T2 to T11 , 20 min before operation and placebo injections after operation . Group Post received placebo injections before operation , and i.v . morphine , i.m . diclofenac and intercostal nerve blocks from T2 to T11 at the end of surgery , before discontinuation of anaesthesia . Visual analogue pain scores , extent and duration of intercostal nerve block , analgesic consumption and complications were assessed during the postoperative period by a single blinded observer . Subjects were followed-up for a minimum of 12 months to determine the incidence of post-thoracotomy pain syndrome . During the first 48 h after operation there were lower pain scores in group Pre when taking a vital capacity breath but there were no significant differences between the groups in any other measure . The effects of pre-emptive analgesia given before surgery appeared to be relatively modest in terms of analgesia , analgesic consumption and long-term outcome and were of limited clinical significance
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 .