Predictors and Outcomes of Sternotomy Conversion and Cardiopulmonary Bypass Assistance in Minimally Invasive Coronary Artery Bypass Grafting

Abstract

Objective

This work's objective was to identify the determinants of conversion of minimally invasive coronary artery bypass grafting to sternotomy, with and without cardiopulmonary bypass assistance, and to compare clinical outcomes in patients who needed conversion.

Methods

This is a prospectively collected data on patients who underwent minimally invasive coronary bypass done by a single surgeon from February 2005 to September 2014. Statistical analyses were expressed as mean values ± standard deviation or proportions.

Results

The total number of patients was 266, with an average age of 62 years. The median number of grafted territories was 2, higher in those with pump assistance (median, 3 grafts; P ≤ 0.01). Predictors for use of cardiopulmonary bypass included diabetes, 3-vessel disease, left circumflex involvement, and small target vessels (P < 0.05). The rate for sternotomy conversion was 3.8%. Risk factors for conversion to sternotomy included smoking, preoperative bradycardia (<50 beats per minute), low intraoperative ejection fraction, inability to tolerate one-lung ventilation, inadequate surgical exposure, and hemodynamic instability. Postoperative complications included superficial thoracotomy infection (3%), sternotomy infection (10%), new atrial fibrillation (3%), and need for blood transfusion (14%). Twelve patients (5%) developed left-sided pleural effusion that required drainage. There were no perioperative deaths, major adverse cardiac event, or stroke.

Conclusions

Minimally invasive coronary bypass grafting with conversion to sternotomy and use of cardiopulmonary bypass is safe. Conversions may be alleviated by an effort to optimize modifiable risk factors and the adequacy of surgical exposure. These data may help develop objective selection criteria to identify patients who are excellent candidates for the procedure.