The incidence of chronic post-sternotomy pain after cardiac surgery - a prospective study

Background: Post-sternotomy pain is sometimes a sequela of cardiac surgery. The incidence, characteristics and clinical course of post-sternotomy pain are not well known. The aim of our study was to determine the incidence of chronic post-sternotomy pain in patients undergoing sternotomy for cardiac surgery in general and according to the specific surgical procedure. Method: In a prospective manner, a group of 349 consecutive patients were evaluated for chronic post-sternotomy pain one year after surgery. The patients were asked in a postal questionnaire to describe and score any persistent pain following the surgical procedure. The patients were classified into 3 subgroups according to surgical procedure. The first group consisted of patients operated for coronary artery by-pass grafting (CABG) including internal thoracic artery grafting (ITAG). The second group included patients operated with CABG without ITAG and the third group of patients with valve replacement without CABG. Result: A total of 318 patients (91%) answered the questionnaire of whom 90 (28%) reported chest discomfort different from what they experienced before surgery. The scoring on the visual analogue scale (VAS, 0-100 mm) showed that 41 patients (13%) reported maximum pain intensity greater than or equal to 30 mm (moderate pain), and 14 of these patients (4%) scored greater than or equal to 54 mm (severe pain). There was no statistically significant difference in pain incidence and pain intensity when comparing the patients subjected to different surgical procedures. Conclusions: This prospective study shows that the overall incidence of non-cardiac pain after sternotomy for cardiac surgery is high (28%). Most patients experience a modest pain intensity but some (1%) report severe pain, never being lower than 54 mm on VAS. The study also indicates that the incidence of pain after sternotomy is not only associated with harvest of the ITA and additional aetiological factors must be sought.