Aortic Arch Replacement with Frozen Elephant Technique - A Single Center Experience Evaluating the Neurological Outcome

Abstract

Introduction: A modern concept for the treatment of extensive aortic disease involving the aortic arch and the proximal descending aorta is the frozen elephant trunk (FET) technique. The perioperative incidence of spinal cord ischemia and stroke is reported to be up to 24% and 16%, respectively. The results on neurological outcome with the FET technique are presented. Methods: Between July 2011 and August 2014, 33 consecutive patients underwent extensive thoracic aorta surgery using the FET technique (n = 11 E-vita hybrid open stent graft, n = 22 Thoraflex hybrid graft). Root replacement was performed in 38.7% (Bentall n = 9, David procedure n = 3) and additional bypass grafting in 6.1% (n = 2). Mean age of these high-risk patients (mean Euroscore II 13.2 ± 15.7) was 63.2 ± 10.7 years (75.8% males). Indications for surgery were as follows: extensive degenerative aneurysm (33.3%, n = 11), acute (36.4%, n = 12), and chronic (30.3%, n = 10) type A dissection. Of these, 3 patients had acute aortic rupture and 3 patients suffered from Marfan syndrome. About one quarter (24.2%, n = 8) were reoperations. Preoperative neurological pathologies were as follows: paraparesis n = 1, monoparesis n = 2, impaired consciousness n = 2. In addition, 4 patients had already been intubated at the referring clinic. For perioperative neurological protection deep hypothermia (< 25°C) and bilateral antegrade perfusion were used and cerebral oxygenation was monitored by NIRS. Results: Cardiopulmonary bypass, aortic clamping, cerebral perfusion, and circulatory arrest times were 262 ± 79, 143 ± 63, 88 ± 31 and 80 ± 28 minute, respectively. The 30-day mortality was 15.2% (n = 5). Of these, 4 patients underwent emergency surgery. Only 1 patient who underwent elective FET died (3%). Permanent and temporary neurological deficit occurred in 6.3% (n = 2) and 15.2% (n = 5), respectively. Paraplegia occurred in 1 patient (3%) who had previous complete thoracoabdominal endovascular stenting. Left recurrent nerve paralysis was observed in 22.6% (n = 7). Conclusion: The above-mentioned regime which involves bilateral antegrade cerebral perfusion in combination with deep hypothermia provides adequate protection for the spinal cord and the brain even during longer periods of circulatory arrest. Due to anatomical reasons, the left recurrent nerve is difficult to protect.