Early and mid-term outcomes of thoracic aortic reconstruction using the frozen elephant trunk technique: a single-center retrospective study

Background. The frozen elephant trunk (FET) technique for the treatment of both thoracic aortic aneurysms and dissections has become universally popular over the past two decades because extensive open surgical reconstruction of the thoracic aorta has been found to be associated with high complication and mortality rates or unfavourable long-term outcomes as it requires repeated interventions. The FET technique has also been shown to produce excellent, immediate and long-term results. Hence, it is important to evaluate the outcomes of thoracic aortic reconstruction using this technique. Aim. This study aimed to investigate immediate and long-term outcomes of the FET technique in patients with thoracic aortic diseases. Methods. We retrospectively analysed the pre-, intra- and post-operative data of 40 patients with distal aortic arch aneurysm who had undergone aortic arch reconstruction using the FET technique at Meshalkin National Research Medical Center from February 2012 to October 2020. To assess the early and long-term post-operative survival of these patients, we categorised them into group I (including 14 patients without aortic dissection) and group II (including 26 patients with type I and type III aortic dissections). Results. The in-hospital survival rates for groups I and II were found to be 68.5% and 95.9%, respectively (log rank, p=0.048). Groups I and II did not differ significantly in the incidence of stroke (7.1% vs 7.7%, respectively; p=0.724) and spinal cord ischaemia (14.3% vs 0%, respectively; p=0.117). Long-term (1-, 3- and 5-year) survival rates in group II remained unchanged at 95.9%, whereas survival rates at 30 days, 6 months and 1 year in group I were 91.3%, 68.5% and 57%, respectively. The risk of mortality was 90% lower in group II than in group I, with a hazard ratio of 0.096 and a 95% confidence interval of 0.01-0.81 (p=0.038). The rates of freedom from thoracoabdominal aortic interventions in group II were 91.8%, 83%, 64.7%, 59.3% and 59.3% at 30 days, 6 months, 1 year, 3 years and 5 years, respectively; these rates in group I were 90.9%, 75.7% and 75.7% at 30 days, 6 months and 1 year, respectively. There was no significant difference between the groups concerning thoracoabdominal aortic interventions (log rank, p=0.587). Conclusion. The use of the FET technique in patients with thoracic aortic diseases is associated with acceptable rates of mortality and thoracoabdominal aortic interventions in immediate and long-term post-operative periods.