Heng Elbert, Stone James R, Kim Joon Bum, Lee Hang, MacGillivray Thomas E, Sundt Thoralf M
Brown University Medical School, Providence, Rhode Island.
Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
Ann Thorac Surg. 2015 Dec;100(6):2095-101; discussion 2101. doi: 10.1016/j.athoracsur.2015.05.105. Epub 2015 Sep 1.
A more aggressive posture toward resection of the dilated aorta has been advocated when associated with bicuspid aortic valve (BAV), based on the notion that aortic material properties are weaker in this setting despite scant data to support or refute this position. The hypothesis that histologic abnormality reflects aortic wall strength was tested by comparing aortas from patients with BAV and trileaflet aortic valve.
Resected aortas associated with BAV (n = 60) and trileaflet aortic valve (n = 24) were compared with normal diameter aortas from patients undergoing cardiac transplantation (n = 16) by five histologic criteria: elastic fiber loss (graded 0-4), smooth muscle cell loss (graded 0-4), medial proteoglycan accumulation (graded 0-3), medial fibrosis (graded 0-3), and atherosclerosis (graded 0-3). Patients with known connective tissue disorders, systemic inflammatory conditions, dissection, or prior heart surgery were excluded.
Patients with BAV were a decade younger and more often had functional stenosis. The extent of elastic fiber loss, smooth muscle cell loss, medial fibrosis, and atherosclerosis was more severe in trileaflet aortic valve than BAV when considered across all diameters and when stratified to those between 4 and 5 cm.
More severe histologic abnormalities associated with trileaflet aortic valve compared with BAV, especially when stratified by diameter, do not support a more aggressive approach to surgical intervention for dilatation associated with BAV. Indeed, if based on histologic diagnosis alone, our findings are suggestive that the converse might be true. Additionally, the lack of correlation between aortic diameter and histologic abnormality in the setting of BAV highlights the inadequacy of diameter alone as a criterion for aortic resection.
对于与二叶式主动脉瓣（BAV）相关的扩张主动脉，有人主张采取更积极的切除态度，其依据是尽管缺乏数据支持或反驳这一观点，但认为在这种情况下主动脉的材料特性较弱。通过比较患有BAV和三叶式主动脉瓣的患者的主动脉，对组织学异常反映主动脉壁强度这一假设进行了检验。
将与BAV（n = 60）和三叶式主动脉瓣（n = 24）相关的切除主动脉与接受心脏移植的患者的正常直径主动脉（n = 16）按照五项组织学标准进行比较：弹性纤维损失（0 - 4级）、平滑肌细胞损失（0 - 4级）、中膜蛋白聚糖积聚（0 - 3级）、中膜纤维化（0 - 3级）和动脉粥样硬化（0 - 3级）。排除患有已知结缔组织疾病、全身性炎症性疾病、主动脉夹层或既往心脏手术史的患者。
患有BAV的患者年龄小十岁，且更常出现功能性狭窄。当考虑所有直径以及分层至4至5厘米之间的直径时，三叶式主动脉瓣的弹性纤维损失、平滑肌细胞损失、中膜纤维化和动脉粥样硬化程度比BAV更严重。
与BAV相比，三叶式主动脉瓣相关的组织学异常更严重，尤其是按直径分层时，并不支持对与BAV相关的扩张采取更积极的手术干预方法。实际上，如果仅基于组织学诊断，我们的研究结果表明情况可能相反。此外，在BAV情况下主动脉直径与组织学异常之间缺乏相关性，凸显了仅以直径作为主动脉切除标准的不足之处。
