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 .
A nondivided intercostal muscle flap further reduces pain of thoracotomy: a prospective randomized trial.
BACKGROUND The pain of thoracotomy  may be related to trauma to the intercostal nerves . METHODS This was a prospect i ve r and omized study of 160 patients . All patients had a functioning epidural , similar type and size thoracotomy , an intercostal muscle flap  ( ICM ) harvested before rib spreading , inferior rib drilling , and postoperative pain management . In one group , the ICM was left intact distally and it dangled ( D group ) ; the ICM in the other was cut distally ( C group ) . Pain was assessed using multiple pain scores . Outcomes assessed were qualitative and quantitative pain scores , number of ribs broken , spirometric values , analgesic use , and return to baseline activity for postoperative days 1 to 5 and weeks 2 , 3 , 4 , 8 , and 12 . RESULTS The D group had 85 patients and the C group , 75 . The groups had similar demographics , types of procedures , and histology . Intrahospital pain scores were similar ; however , at postoperative weeks 3 , 4 , 8 , and 12 , the D group had significantly lower mean numeric pain scores and was using fewer analgesics ( p < 0.05 for all ) . At 12 weeks , patients in the D group were more likely to have returned to baseline activity ( p = 0.002 ) . CONCLUSIONS An ICM flap reduces pain . Harvesting and then leaving the ICM flap intact instead of cutting it before rib spreading further reduced thoracotomy pain . This technique , when added to rib drilling , leads to reduced pain on postoperative weeks 3 to 12 , to quicker return to baseline activity , and lessens the need for analgesics
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 .