Individualized thoracic aortic replacement for the aortopathy of biscuspid aortic valve disease

Abstract

Background and aim of the study: Bicuspid aortic valve (BAV) disease is associated with an aortopathy resulting in aneurysmal dilatation spanning the root, ascending, and arch segments. To date, no large series of proximal aortic replacement in this population has been reported. The study aim was to report contemporary surgical outcomes for proximal aortic replacement in BAV disease, and to examine the relationships between valve morphology, valve pathophysiology, and pathology of the thoracic aorta.

Methods: Between September 2005 and December 2009, a total of 100 consecutive patients (mean age 54 +/- 13 years; range: 29-80 years) with BAV and proximal aortic enlargement underwent aortic replacement at a single referral institution. Of these patients, 16% had undergone prior aortic valve replacement (AVR). The aortic repair was individually tailored to treat the aortic valve and thoracic aortic pathology, and included supracoronary ascending aortic (AA) replacement (n = 17), AVR with separate supracoronary AA replacement (n = 39), aortic root replacement (n = 42), and valve-sparing root replacement (n = 2). Concomitant arch replacement was performed in 82 patients (80 hemi-arch, two full arch). Other concomitant cardiac procedures were performed in 28 patients.

Results: The 30-day/in-hospital rates of death and stroke were both 1%. The predominant aortic valve pathophysiology was aortic stenosis (AS; 33%), aortic insufficiency (AI; 29%), mixed AS/AI (17%), normally functioning BAV (17%), and unknown (4%). Valve morphology included Sievers Type I, R/L (75%), Type I, R/N (9%), Type I, L/N (2%), Type 0 (7%), and Type II (7%). BAV patients with predominantly AI had more frequent root dilatation (62%) than those with either AS (30%) or normal valve function (35%). Based on BAV morphology, there were no significant differences in maximal thoracic aortic diameters between groups. At a mean follow up of 16 months, there were no late deaths or valve-related complications.

Conclusion: Proximal aortic replacement in patients with BAV can be performed with low rates of mortality and morbidity. The pathologic anatomy of the thoracic aorta was not predicted by the aortic valve morphology, although dilation of the aortic root was most common in BAV patients with a predominant AI pathophysiology. These findings convey the safety and feasibility of treating concomitant aortopathy, including arch replacement as needed, and may help tailor the specific operation needed to the patient's pathology.

Figure 1

Explanted Sievers Type II BAV with two raphe (monocuspid valve). All patients with this Sievers subtype in the present series exhibited a mixed aortic stenosis/insufficiency hemodynamic pattern (N=non, R=right, and L=left coronary cusp).

Figure 2

(A) Numerical distribution of BAV hemodynamic patterns and (B) correlation with extent of maximal aortic enlargement. (C) BAV patients with predominant aortic insufficiency (AI) had a significantly greater likelihood of necessitating aortic root replacement relative to patients with predominantly aortic stenosis (AS), mixed AI/AS, and normally functioning BAV (* P<0.05). (D) Correlation between BAV morphology (Sievers classification, types I, II, 0) and hemodynamic pattern of BAV disease.

Figure 3

(A) Representative three-dimensional (3D) MRA imaging for a typical BAV patient requiring proximal arch (hemi-arch) replacement. Note that the aorta does not become normal in caliber until just distal to the left common carotid artery. (B) 3D CTA of one of the two patients in the present series who required total arch replacement. Note that in this case the aorta does not become normal in diameter until just distal to the left subclavian artery. (C) 3D CTA of a patient who did not require concomitant arch replacement. Note that the ascending aorta becomes normal in caliber several centimeters proximal to the innominate artery.