Iatrogenic aortic dissection during aortic root replacement in an older Loeys–Dietz syndrome type III patient with no family history of aortic disease: a case report

BACKGROUND: Iatrogenic aortic dissection during cardiac surgery is a rare but critical complication. At present, no strategies have been developed to prevent it. We herein report a case of intraoperative aortic dissection during aortic root replacement in an older patient with Loeys–Dietz syndrome type III who had no family history of aortic disease. CASE PRESENTATION: A 60-year-old man was admitted to the hospital for Stanford type B acute aortic dissection and given conservative treatment. He was found to have aortic root dilatation and severe aortic regurgitation. Thus, elective Bentall procedure was performed. Postoperative computed tomography showed new Stanford type A aortic dissection that may have developed due to aortic cannulation during surgery. The patient was given conservative treatment and successfully discharged to home at postoperative day 34. Although he had no family history of aortic disease, a genetic test revealed an unreported SMAD3 frameshift mutation (c.742_749dup, p. Gln252ThrfsTer7), and the patient was diagnosed with Loeys–Dietz syndrome type III. CONCLUSION: In patients with connective tissue disorder, aortic manipulations may become the cause of critical complications. Avoiding the use of invasive techniques, such as cannulation and cross-clamping, and implementing treatment strategies, such as perfusion from other sites than the aorta and open distal anastomosis, can prevent these complications, and may be useful treatment modalities. The possibility of connective tissue disease should be considered even if the patient is older and has no family history of aortic disease.