Discussion
Aortic dissections and aneurysms are rare complications in patients with SLE; however, their incidence is higher in patients with SLE than in age- and sex-matched controls1, 2. Patients with SLE develop aortic aneurysms at a relatively early age4. Pathological changes in patients with SLE include cystic medial necrosis with mucopolysaccharide deposition and Marfan-like changes, such as destruction of elastic fibers5. Interestingly, histopathology results from the present case showed a tear in the tunica media elastic fibers, suggesting that this was the cause of the aortic dissection 17 years previously. Various factors, other than atherosclerosis, have been postulated to contribute to the formation of aortic aneurysms in patients with SLE. Mucoid degeneration, vascular injury, hypertension, arteriosclerosis, and steroid therapy are reportedly associated with aneurysm formation 6. Long-term steroid therapy inhibits chondroitin sulfate and granulation tissue formation, affecting connective tissues and increasing the incidence of atherosclerosis6, 7. The thoracic aorta is considered more resistant to atherosclerosis than the abdominal aorta. The difference in susceptibility to lipid deposition and subsequent plaque formation suggests differences in the cellular and extracellular compositions of the thoracic and abdominal aorta. This supports a different pathophysiological mechanism for the development of TAA and AAA8. Vasculitis and cystic medial degeneration reportedly cause TAA, whereas atherosclerotic changes due to long-term steroid therapy cause AAA in patients with SLE9. The present case was of a TAA with severe atherosclerotic lesions. These lesions and her early age suggest that the TAA may have been influenced by SLE and steroid therapy.
The incidence of postoperative pseudoaneurysm after cardiac surgery is estimated to be <0.5%10. Previous reports include pseudoaneurysm occurring 1 year after acute aortic dissection repair3, and true aneurysm recurrence 5 months after AAA repair in SLE patients11. We should consider the possibility of true aneurysms developing in patients with SLE even after total arch replacement and consider using a technique that does not leave the aortic wall short of the sino-tubular junction.