Methods: Between January 2012 and December 2012, a total of 167 procedures in 163 patients who were operated by a single surgeon were analyzed. Early mortality rates were calculated. Intensive care unit stay more than one week was identified as the marker of morbidity. We adopted a threshold duration of 120 min of cardiopulmonary bypass time to evaluate the surgical technical difficulty. The patients were divided into six complexity levels based on the Aristotle basic scores (ABC) and Aristotle comprehensive scores (ACC). Complications for each procedure were classified.

Results: The mean ABC and ACC scores were calculated as 7.5±2.7 and 8.6±3.5, respectively. Thirty three patients were neonates (23.9%) and 46 patients were infants (28.2%). The overall hospital mortality rate was 12.5% (n=21 procedures). Based on the complexity level, 3.7% at ACC level 1, 4.5% for level 2, 13.6% for level 3, 18.8% for level 4, 66.6% for level 5, and 100% for level 6 (only one patient). The overall morbidity index was 33.5% (n=56 procedures). It increased form 3.7% at level 1 to 100% at level 5. The index of surgical difficulty was estimated to be 31.7% (n=53 procedures) and zero at level 1 and it increased up to 66% at level 5. A strong correlation was found between the ACC scores and mortality (p<0.019), indices of morbidity (p<0.001) and surgical difficulty (p<0.001). We detected 155 complications in 43.5% (n=71 patients) of the patients.

Conclusion: Our study confirms that the Aristotle scoring system offers an opportunity for a detailed analysis to evaluate the surgical results in congenital heart surgery. It is possible to compare the results yearly in a center or among the centers across the world. These data can be used to improve the quality of care.