ANATOMY OF THE AORTIC ROOT WITH PARTICULAR EMPHASIS ON OPTIONS FOR ITS SURGICAL ENLARGEMENT

Background and aims of the study: The aortic root is a frequent site o f surgical intervention, both in adults and children, yet there is amb iguity about the precise nature and relation of the various structures composing the aortic root. The present review aims to clarify these a mbiguities and to explain the morphological basis of surgical procedur es for enlargement of the aortic root. Materials and methods: Using au topsied specimens of normal hearts, the morphology of the attachment o f the leaflets, the interleaflet triangles and the circular ventriculo -arterial junction of the aortic root were studied in detail, paying s pecial regard to fibrous and muscular continuity, relation to the atri oventricular conduction axis, and the coronary arterial branching. Sur gical dissections and incisions required for enlargement of the aortic root were simulated in these specimens. Results: It was evident that the locus of attachment of aortic valvar leaflets takes the form of th ree (semilunar) crescents. This attachment is not circular, as the wor d 'annulus' suggests, neither does it correspond to the anatomical ven triculo-arterial junction. During implantation of a mechanical valve i n the aortic position, a circular prosthetic valve ring is sutured on to the attachments of the native valvar leaflets. This must entail som e distortion when the sutures are tied. Analysis of autopsied specimen s showed that, on completion of the process of suturing, the location of the prosthetic valve is close to the anatomic ventriculo-arterial j unction - one of the true annular regions of the aortic root. Conclusi ons: The continuity of the aortic valvar leaflets and the interleaflet triangles with structures such as the aortic (anterior) leaflet of th e mitral valve posteriorly, and with the muscular ventricular septum a nteriorly, provide an opportunity for surgeons to enlarge the aortic r oot by widening of the anatomic ventriculo-arterial junction.