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 .
Effect of Cryoanalgesia Combined with Intravenous Continuous Analgesia in Thoracotomy Patients
Fifty patients undergoing thoracotomy was studied to compare the effects of cryoanalgesia combined with intravenous continuous analgesia ( IVCA ) .  Patients were r and omized into two groups : IVCA group and IVCA-cryo group .  Subjective pain intensity was assessed on a visual analogue scale at rest ( VAS-R ) and during movement ( VAS-M ) . Analgesic requirements were evaluated over the 7 days following surgery . Forced vital capacity ( FVC ) and forced expiratory volume in 1 sec ( FEV1 ) were measured before operation , on the 2nd and 7th postoperative days ( POD ) . We interviewed patients by telephone to evaluate the prevalence of post-thoracotomy pain at the 1st , 3rd , and 6th months postoperatively . No significant differences were observed between the two groups with respect to postoperative pain , analgesic requirements , side effects , respiratory complications , or prevalence of post-thoracotomy pain . However , a significant increase in FVC and FEV1 was observed on the 7th POD in IVCAc-ryo group . The incidence of the post-thoracotomy pain at the 1st , 3rd , and 6th months postoperatively was 68 , 60 , and 44 % in IVCA group , and 88 , 68 , and 28 % in IVCA-cryo group , respectively . Our study showed that cryoanalgesia combined with IVCA effectively restore respiratory function on 7th POD , but that it was not effective at reducing the incidence of post-thoracotomy pain
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 .