Abstract: ISMICS 2006 Annual Meeting Abstracts
Minimally invasive direct coronary artery bypass (MIDCAB) has become a routine operation. Yet, some technical and anatomical aspects as well as human factors deserve special attention and are the source of potential error.
1344 standard MIDCAB-procedures performed between 1996 and 2004 were analysed for ten major complications and risk adjusted early mortality rate. The learning curves and the assessment of perioperative outcome were analysed using standard descriptive statistics and CUSUM failure analysis for the eight involved surgeons with a personal experience ranging from 27–443 procedures.
The incidence of in-hospital mortality was 0.8% and compared favourably with the predicted mortality calculated by the logistic EUROSCORE (3.6% p<0,01). There were significant differences between the “learning phase” (less than 50 operations), the “intermediate phase” and the “expert phase” (more than 100 operations). Perioperative mortality dropped after the learning phase from 0.8% to 0.4% (p<0.05). The need for intraoperative conversion decreased from 2.7% to 0.2% (p<0.05) after 150 operations. The overall complication rate and need for reintervention dropped after 100 operations from 12.7% to 7.1% (p<0.05) and 5.1% to 2.8% (p<0.05), respectively. CUSUM analysis revealed significant differences between surgeons with regard to the learning curves and complications (3.6%–29.6% p<0.01) despite a similar patient risk profile. Four surgeons crossed the 95% reassurance boundary after 50 or 100 operations whereas two surgeons reached the 95% alarm-line indicating unacceptable high failure rate.
MIDCAB has become a procedure with low mortality and complication rates but Results are case-load dependent. CUSUM analysis allows for a breakdown of complication rates over time displaying individual surgeons' strengths.