Persistent and acute postoperative pain after cardiac surgery with anterolateral thoracotomy or median sternotomy: A prospective observational study.

Objective: The primary objective of this study was to compare the association between cardiac surgical approach (thoracotomy vs. sternotomy) and incidence of persistent postoperative pain at 3 months. Secondary objectives were the incidence and intensity of persistent pain at 6 and 12 months, acute postoperative pain, analgesic requirement and its side effects.

Design: Single-center, prospective, observational study. Recruitment between December 2017 and August 2018.

Setting: Perioperative care at university-affiliated tertiary care centre.

Patients: 202 adults scheduled for cardiac surgery. Patients with chronic pain or behavioural disorder were excluded.

Interventions: Thoracotomy (n = 106) and sternotomy (n = 96).

Measurements: Pain scores and pain medication requirements from extubation until hospital discharge. Persistent postoperative pain was assessed using a telephone questionnaire.

Main Results: Incidence and intensity of pain was not significantly different between thoracotomy or sternotomy either in the short- or in the long-term follow-up. Incidence of persistent postoperative pain showed no differences between groups (30.2 vs 22.9% at 3 months (p = 0.297), 10.4 vs 7.3% at 6 months (p = 0.364) and 7.5 vs 7.3% at 12 months (p = 0.518) in thoracotomy and sternotomy group). A significant decrease of pain incidence was observed between 3 and 6 months (p < 0.001) but not between 6 and 12 months (p = 0.259) in both groups. ANOVA of repeated measures adjusted for confounding variable showed a decrease of acute pain intensity over time (p = 0.001) with no difference between groups (p = 0.145). Acute pain medication requirements were not different between the groups (p = 0.237 for piritramide and p = 0.743 for oxycodone) with no difference in their side effects.

Conclusions: Our study showed no difference in short- or long-term pain in patients undergoing anterolateral thoracotomy or median sternotomy. Both groups showed a decrease in persistent postoperative pain incidence between 3 and 6 months without any significant changes at 12 months.