Aortic valve opening and closure: the clover dynamics

Aortic valve leaflets are asymmetric and correlated with the origin of coronary arteries

Background

Asymmetry of the aortic valve leaflets has been known since Leonardo Da Vinci, but the relationship between size and shape and origin of the coronary arteries has never been examined. Our aim was to evaluate this anatomy in a population of pediatric patients using a cross-sectional study design.

Methods

Consecutive pediatric patients with trans-esophageal echocardiography (TEE), with or without trans-thoracic echocardiography (TTE), were included in our study. Exclusion criteria: (I) bicuspid aortic valve; (II) aortic valve stenosis; (III) hypoplasia of aortic valve annulus, or aortic root; (IV) truncal valve; (V) coronary artery atresia; (VI) previous surgery on aortic valve and/or coronary arteries. In pre-operative TTE and intra-operative TEE inter-commissural distance and length of aortic valve leaflets were measured in short axis view in the isovolumic phase of systole. Echocardiography investigations, anonymized and randomly coded, were independently reviewed by at least two readers. Echocardiography, angiography, cardiac computed tomography (CT) scan and magnetic resonance imaging (MRI), and operative notes were reviewed to identify origin of coronary arteries.

Results

Two hundred sixty-one pediatric patients were identified, 93 excluded per our criteria, leaving 168 patients, age 2.6±4.3 years, weight 12.87±17.34 kg, 128 (76%) with normal and 40 (24%) with abnormal coronary arteries. In TTE and TEE measurements the non-coronary leaflet had larger area (P<0.001), while the right and left had equal areas, but different shape, with the left leaflet longer (P<0.001) and narrower (P=0.005) than the right. With the major source of blood flow from the right coronary sinus, the non-coronary leaflet was still the longest. However, there was no statically significant difference between the size and shape previously observed between the right and left leaflets.

Conclusions

Our study showed asymmetry of size and shape among aortic valve leaflets, and a relationship with coronary artery origin. The complex aortic root anatomy must be approximated to optimize function of any surgical repair. These findings also may prove useful in the pre-operative definition of coronary artery anatomy and in the recognition of coronary artery anomalies.

Valve sparing root replacement: an update

PURPOSE OF REVIEW

Until the year 2000, the publications concerning aortic valve sparing (AVS) did not exceed 20 articles; in the following years almost 300 publications have appeared. Over 35 years from the introduction of valve sparing techniques and 500 years after the death of Leonardo da Vinci, this review highlights the significant steps in modern imaging techniques and the excellent clinical results in the field of reconstructive aortic root surgery.

RECENT FINDINGS

AVS operations underwent significant modifications over the last few years making it reproducible with satisfactory outcomes. The extraordinary potential of imaging opens new boundless horizons in the perspective of an increasingly patient-tailored surgical planning. The basic surgical concepts include the preservation and resuspension of the aortic valve in a near-normal environment (with the creation of functionally suited neo-aortic sinuses) and the re-establishment of a normal relationship of the aortic root components.

SUMMARY

Today is possible to perform a reimplantation procedure with the creation of neo-sinuses or a remodeling procedure with the addition of annular support. Both procedures can now guarantee an anatomical root reconstruction and an increased long-term durability. AVS operations have become established alternatives to Bentall procedures for patients with aortic root pathology, especially in young patients.

Surgical treatment of mitral regurgitation

PURPOSE OF REVIEW

Mitral repair is the best treatment for degenerative mitral regurgitation. Many patients are referred too late for optimal outcomes. The US repair vs. replacement rate is only 60-80%, at a time when the inferiority of replacement has been established. Therefore, widely used traditional techniques of repair are being reappraised.

RECENT FINDINGS

Identification of risk factors predictive of poor early and late outcome have improved timing for surgical referral. Composite risk scores have been developed. Novel echocardiographic, cardiac MRI, and molecular level risk factors could improve timing. Analysis of factors contributing to low repair rates is also of critical importance. The role of institutional and surgeon volumes have been identified. More detailed data on the importance of dynamic function of the mitral valve have led to improved repair techniques such as intraoperative simulation of end diastole and early systole, use of expanded polytetrafluoroethylene neochords instead of leaflet resection, and dynamic instead of rigid annuloplasty.

SUMMARY

Our perception of mitral regurgitation has changed from a seemingly simple condition to one of considerable complexity at multiple levels. National guidelines should be studied and followed.