Association between sternotomy versus thoracotomy and the prevalence and severity of chronic postsurgical pain after mitral valve repair: An observational cohort study

Objective Investigate differences in the prevalence and severity of chronic postsurgical pain (CPSP) after cardiac surgery via thoracotomy versus sternotomy are not well-understood. Design An observational cohort study. Setting A tertiary care hospital. Participants Four hundred twenty-eight patients (sternotomy: 192 patients, thoracotomy: 236 patients) who underwent mitral valve repair. Interventions A questionnaire about the severity of surgical wound pain evaluated with a numerical rating scale (NRS) was sent. NRS responses for current pain, peak pain in the last four weeks, and average pain in the last four weeks were evaluated. Measurements and Main Results The main outcomes were the severity of CPSP evaluated using NRS and the prevalence of CPSP. CPSP was defined as pain >0 that developed after a surgical procedure. During the median follow-up of 29 months, 79 patients complained of CPSP. (sternotomy: 15 patients, thoracotomy: 64 patients). Multivariate ordinal logistic regression showed that NRS responses for current pain (adjusted odds ratio [aOR], 3.17; 95% confidence interval [CI] 1.64-6.12; p = 0.001), peak pain in the last four weeks (aOR, 2.00; 95% CI 1.11-3.61; p = 0.021), and average pain in the last four weeks (aOR, 2.21; 95% CI 1.31-3.72; p = 0.003) were significantly higher in patients who underwent thoracotomy. Multivariate logistic regression showed that thoracotomy was an independent predictor of CPSP (aOR, 3.63; 95% CI 1.67-7.88; p = 0.001). Conclusions The prevalence and severity of CPSP were higher among patients who underwent mitral valve repair via thoracotomy than sternotomy.