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 .
Comparison of epidural analgesia and intercostal nerve cryoanalgesia for post‐thoracotomy pain control
Epidural analgesia is regarded as the gold method for controlling post‐thoracotomy pain . Intercostal nerve cryoanalgesia can also produce satisfactory analgesic effects , but is suspected to increase the incidence of chronic pain . However , r and omized controlled trials comparing these two methods for post‐thoracotomy acute pain analgesic effects and chronic pain incidents have not been conducted previously . We studied 107 adult patients , allocated r and omly to thoracic epidural bupivacaine and morphine or intercostal nerve cryoanalgesia .  Acute pain scores and opioid‐related side effects were evaluated for three postoperative days . Chronic pain information , including the incidence , severity , and allodynia‐like pain , was acquired on the first , third , sixth and twelfth months postoperatively . There was no significant difference on numeral rating scales ( NRS ) at rest or on motion between the two groups during the three postoperative days . The patient satisfaction results were also similar between the groups . The side effects , especially mild pruritus , were reported more often in the epidural group . Both groups showed high incidence of chronic pain ( 42.1–72.1 % ) , and no significance between the groups . The incidence of allodynia‐like pain reported in cryo group was higher than that in Epidural group on any postoperative month , with significance on the sixth and the twelfth months postoperatively ( P<0.05 ) . More patients rated their chronic pain intensity on moderate and severe in cryo group and interfered with daily life ( P<0.05 ) . Both thoracic epidural analgesia and intercostal nerve cryoanalgesia showed satisfactory analgesia for post‐thoracotomy acute pain . The incidence of post‐thoracotomy chronic pain is high . Cryoanalgesia may be a factor that increases the incidence of neuropathic 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 .