Chronic pain in thoracotomy.

Background/aims Chronic pain is frequent after thoracotomy (Wildgaard et al., 2009; Guastella et al., 2011). According to a recent Danish study with a follow-up period of 22 months, 33% of the patients developed pain after thoracotomy, and 4-12% of the patients experienced severe pain (Wildgaard et al., 2011). The mechanisms underlying chronic pain after surgery are not fully known, but several risk factors have been identified, e.g. intraoperative nerve damage and acute postoperative pain (Kehlet et al., 2006). A few studies have suggested a correlation between nerve damage during surgery and the development of pain after thoracotomy (Benedetti et al., 1997, 1998; Rogers et al., 2002). We plan to investigate if intraoperative nerve damage is responsible for the development of pain and sensory abnormalities after thoracotomy. Methods Sixty individuals with normal sensibility on the thorax will be included preoperatively. Motor and sensory nerve conduction studies (NCS) will be performed during surgery. Post-surgical follow-up with questionnaires and bilaterally Quantitative Sensory Testing (QST) on the thorax will be performed according to the protocol of the German Research Network on Neuropathic Pain (DFNS). Before implementing the neurophysiological measurements in humans, they have been tested in pigs. Results Neurophysiological measurements in pigs have shown that it is possible to do NCSs on both motor and sensory intercostal nerves, suggesting that measurements are possible in humans. Inclusion of patients is pending. Conclusion The preliminary results will be presented at the congress.