Background

The arterial switch operation (ASO) has become a safe, reproducible surgical procedure with low mortality in experienced centers. We examined morbidity, which remains significant, particularly for complex ASO.

Methods

From 2003 to 2011, 101 consecutive patients underwent ASO, arbitrarily classified as “simple” (n = 52) or “complex” (n = 49). Morbidity was measured in selected complications and postoperative hospitalization. Three outcomes were analyzed: ventilation time, postextubation hospital length of stay, and a composite morbidity index, defined as ventilation time + postextubation hospital length of stay + occurrence of selected major complications. Complexity was measured with the comprehensive Aristotle score.

Results

The operative mortality was zero. Twenty-five major complications occurred in 23 patients: 6 of 25 (12%) in simple ASO and 19 of 49 (39%) in complex ASO (p = 0.002). The most frequent complication was unplanned reoperation (15 vs 6, p = 0.03). No patients required permanent pacing. The complex group had a significantly higher morbidity index and longer ventilation time and postextubation hospital length of stay. In multivariate analysis, factors independently predicting higher morbidity were the comprehensive Aristotle score, arch repair, bypass time, and malaligned commissures. Myocardial infarction caused one sudden late death at 3 months. Late coronary failure was 2%. Overall survival was 99% at a mean follow-up of 49 ± 27 months.

Conclusions

In this consecutive series without operative mortality, morbidity was significantly higher in complex ASO. The only anatomic incremental risk factors for morbidity were aortic arch repair and malaligned commissures, but not primary diagnosis, weight less than 2.5 kg, or coronary patterns.

This report from a single institution describes the results of consecutive pediatric heart operations done by trainees under the supervision of a senior surgeon. The 3.1% mortality seen in 1067 index operations is comparable across procedures and risk bands to risk-stratified results reported by the Society of Thoracic Surgeons. With appropriate mentorship, surgeons-in-training are able to achieve good results as first operators.

We describe the case of a 76-year old female who presented with a Type A aortic dissection requiring repair with an interposition graft and aortic valve replacement. Post-operatively she had clinical features and computerised tomographic images suggestive of a pulmonary embolus and died 24 hours later. The extremely rare finding of intramural thrombus occluding the right pulmonary artery was seen at post mortem.