Endovascular stent graft repair has become a common treatment for complicated Stanford type B aortic dissection to restore true lumen flow and induce false lumen thrombosis. Using computational fluid dynamics, this study reports the differences in flow patterns and wall shear stress distribution in complicated Stanford type B aortic dissection patients after endovascular stent graft repair. Five patients were included in this study: 2 have more than 80% false lumen thrombosis (group 1), while 3 others had less than 80% false lumen thrombosis (group 2) within 1 year following endovascular repair. Group 1 patients had concentrated re-entry tears around the abdominal branches only, while group 2 patients had re-entry tears that spread along the dissection line. Blood flow inside the false lumen which affected thrombus formation increased with the number of re-entry tears and when only small amounts of blood that entered the false lumen exited through the branches. In those cases where dissection extended below the abdominal branches (group 2), patients with fewer re-entry tears and longer distance between the tears had low wall shear stress contributing to thrombosis. This work provides an insight into predicting the development of complete or incomplete false lumen thrombosis and has implications for patient selection for treatment.
Acute type A aortic dissection remains one of the most challenging conditions in aortic surgery. Despite the advancements in the field, the mortality rate still remains high. Though there is a general consensus that the ascending aorta should be replaced, the distal extension of the surgery still remains a controversy. Few surgeons argue for a conservative approach to reduce operative and postoperative morbidity while others considering the problems associated with "downstream problems" support an aggressive approach including a frozen elephant trunk. The cohort in the Indian subcontinent and APAC is far different from the western world. Many factors determine the decision for surgery apart from the pathology of the disease. Economy, availability of the suitable prosthesis, the experience of the surgeon, ease of access to the medical facility all contribute to the decision making to treat acute type A dissection.
Delayed ascending aortic dissection following coronary artery bypass surgery is a rare but lethal complication. We present the case of a 54-year-old man with a delayed acute Stanford A aortic dissection following an off-pump coronary artery bypass surgery in preexisting chronic type B disease. Such a case of an iatrogenic acute aortic dissection poses a significant challenge and dilemma in choosing the best technique for coronary revascularization in this group of patients. The pathophysiology and technical options are discussed.
The incidence of infection following TEVAR is low. To the best of our knowledge, this is the first case report of post thoracic endovascular aortic repair (TEVAR) with Streptococcus viridans graft infection. A 54-year-old male underwent TEVAR for dissecting thoracic aneurysm with spinal ischaemia. He had an eventful recovery with prolonged period of stay in intensive care unit. Three months later, he presented with persistent chest discomfort and fever. Computed tomography (CT) of the thorax revealed evidence of graft infection and the blood culture grew Streptococcus viridans. The rarity of TEVAR graft infection due to Streptococcus viridans and its management are being discussed.