Does Minimally Invasive Mitral Valve Repair Mean Less Postoperative Pain?

Background: Rapid recovery after minimally invasive mitral valve (MV) repair has been demonstrated in many studies, but the issue of postoperative pain has not been fully elucidated. We evaluated pain scores and medication use in patients undergoing MV repair by minimally invasive surgery (MIS) and open sternotomy (OS). Methods: Between 2008 and 2019, 1332 patients underwent isolated MV repair by OS, and 913 underwent minimally invasive MV repair. After 1:1 propensity score matching, the study included 709 patients in each group. Opioid use was quantified as oral morphine equivalents in milligrams for each hospital day. The highest pain scores were collected from a visual analogue scale at 6-hour intervals. Predictive modeling was employed to compare pain medications and pain scores between the groups. Results: The postoperative median length of stay was 3 (3-4) and 5 (4-5) days for the MIS and OS groups, respectively (P < .001). The predicted geometric mean oral morphine equivalents demonstrated lower opioid use for the MIS group compared with the OS group for the first 4 days. However, the predicted mean pain score was higher in the first 24 hours for the MIS group compared with the OS group (4.7 [4.5-4.8] vs 4.4 [4.3-4.5], respectively, on a visual analogue scale of 0 to 10). Conclusions: MV repair by MIS methods was associated with decreased opioid use but not with decreased postoperative pain scores. Possible explanations include the difference in incision site pain and subjective differences in postoperative pain expectations.