Aortic Root Replacement with a Composite Valved Conduit

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Currently there are several operative techniques in use aroundtheworldtoaddressaorticrootpathologicproblems. These include valve-sparing aortic root replacement, stentless porcine aortic root replacement, pulmonary autograft root replacement, and composite valved graft conduits (CVG) housed with either a mechanical or in some cases a bioprosthetic valve. The CVG root replacement is the most time tested of all options and was first described by Bentall and DeBono in 1968. 1 Since then there have been many published series that have extended out beyond 20 years that demonstrate the efficacy of this approach. The indications for aortic root replacement include aneurysmal disease, aortic dissection when the primary tear occurs in the aortic root or with concomitant aortic valve disease or aneurysmal disease, and invasive aortic valve endocarditis that involves the aortic root. Most commonly aortic root replacement is performed for aneurysmal disease that stems from a degenerative process or is secondary to a genetic abnormality that predisposes to proximal aortic dilation as in Marfan syndrome, Loeys‐Dietz syndrome, Ehlers‐Danlos syndrome vascular-type (type IV), familial aortic aneurysm or dissection syndromes, and aneurysm associated with bicuspid aortic valve. Abnormal aortic root and ascending aortic dimensions have been determined based on patient age and body size. Accrual of large amounts of echocardiographic and crosssectional imaging data from normal individuals has allowed the development of regression formulas and nomograms to define abnormal aortic dilation. For example, an individual 18 to 40 years old will have an average aortic diameter at the sinus level equal to 0.97 (1.12 BSA [m 2 ]) (cm). The upper limit of normal is 2.1 cm/m 2 for the sinus segment in most adults. The aorta is pathologically dilated if its diameter exceedsthenormforagivenageandbodysurfacearea(BSA). Itisdefinedasananeurysmifitsdiameteris50%greaterthan the norm. There remains some debate as to what the indication for operative intervention should be based on maximal orthogonal diameter alone without consideration of other clinical factors like aortic valve pathologic complications. Clearly, there are cohorts of patients with aortic root and ascending aortic aneurysms that are at higher risk of an aortic catastrophe (dissection, disruption, or sudden death) than others, like patients with a bona fide connective tissue disorder or family history of aortic dissection. Moreover, surgeon experience with aortic root replacement operations varies widely. Highvolumecentershavetendedtogeneratethebestresults,