Two-Stage Surgery Using FROZENIX Partial ET for Frozen Elephant Trunk Technique and Open Descending Aortic Replacement in a Patient With Recurrent Type B Aortic Dissection and Microscopic Polyangiitis: A Case Report.

The frozen elephant trunk (FET) technique, initially developed as a one-stage procedure to treat extensive thoracic aortic aneurysms, has since been adapted to address acute and chronic aortic dissections by closing entry tears and expanding the true lumen. It has become widely adopted due to its effectiveness in managing aortic diseases. We present the case of a 39-year-old female with microscopic polyangiitis (MPA) who developed recurrent type B aortic dissection accompanied by rapid expansion. The patient, a compromised host with multiple comorbidities such as glomerulonephritis, chronic renal failure, alveolar hemorrhage, and acute pancreatitis, required urgent surgical intervention. Given the complexity of her condition and the high risks associated with direct surgery, a staged approach was selected. The first stage involved using a novel FET prosthesis, the FROZENIX Partial ET (FPET), inserted via median sternotomy, followed by a left thoracotomy for non-deep hypothermic circulatory arrest (non-DHCA) descending aortic replacement. The surgery led to favorable outcomes without any major complications or sequelae. FPET offers distinct advantages in this complex scenario. Its design features a 2 cm stent-free distal section, which reduces the risk of distal stent graft-induced new entries (dSINEs) and simplifies anastomosis during the second stage of surgery. For patients with severe comorbidities and anatomical challenges that make the thoracic endovascular aortic repair (TEVAR) unsuitable, a staged open surgical approach is a viable alternative, mitigating the risks linked to DHCA. This case underscores the utility of a staged surgical approach using FPET in managing complicated chronic type B aortic dissection in patients with significant comorbidities. The FPET prosthesis facilitates effective lesion control while minimizing the risk of dSINEs and streamlining subsequent surgical procedures, presenting a promising strategy for similar complex cases.