Perioperative factors related to the severity of vocal cord paralysis after thoracic cardiovascular surgery

BACKGROUND Vocal cord paralysis (VCP) is a rare complication of thoracic cardiovascular surgery. In severe cases, life-threatening airway obstruction may occur. OBJECTIVE To evaluate the incidence and severity of VCP among patients who underwent thoracic cardiovascular surgery and to identify possible risk factors. DESIGN Single-centre retrospective review of adult patients. SETTING Osaka University Hospital, Suita, Japan, from January 2013 to August 2015. PATIENTS We included 688 patients in the final analysis. Preoperative, intraoperative and postoperative data were collected from medical records. Patients with preoperative VCP or tracheostomy prior to extubation were excluded. The VCP severity in relation to functional recovery was graded using the following categories: absent; mild, remission at 6 months; moderate, partial or persistent VCP at 6 months; or severe, airway obstruction after extubation requiring reintubation. An otolaryngologist diagnosed all VCP cases. MAIN OUTCOME MEASURES The incidence and severity of VCP after extubation. RESULTS The incidence (number) of VCP was 4.7% (32), with those of mild, moderate and severe VCP being 1.7% (12), 1.5% (10) and 1.5% (10), respectively. The ICU stay was significantly longer in patients with severe VCP than in patients without VCP [12.5 days (interquartile range 5.5 to 25.5) vs. 3 days (interquartile range 2 to 5), P = 0.0002]. In our multivariable analysis, type 2 diabetes mellitus [odds ratio (OR) 1.853, P = 0.009], intubation period (OR per 24 h 1.136, P = 0.014), ascending aortic arch surgery with brachiocephalic artery reconstruction (OR 8.708, P < 0.001) and ventricular assist device implantation (OR 3.460, P = 0.005) were independent predictors for VCP. CONCLUSION The identification of these risk factors may facilitate screening for VCP before extubation and possibly help anaesthesia personnel to be prepared to treat VCP-related airway obstruction should it occur.