Is there such a thing as the "tendon of the infundibulum" in the heart?

Heart valve macro- and microstructure

Each heart valve is composed of different structures of which each one has its own histological profile. Although the aortic and the pulmonary valves as well as the mitral and the tricuspid valves show similarities in their architecture, they are individually designed to ensure optimal function with regard to their role in the cardiac cycle. In this article, we systematically describe the structural elements of the four heart valves by different anatomical, light- and electron-microscopic techniques that have been presented. Without the demand of completeness, we describe main structural features that are in our opinion of importance in understanding heart valve performance. These features will also have important implications in the treatment of heart valve disease. They will increase the knowledge in the design of valve substitutes or partial substitutes and may participate to improve reconstructive techniques. In addition, understanding heart valve macro- and microstructure may also be of benefit in heart valve engineering techniques.

The Ross Procedure: New Insights Into the Surgical Anatomy

BACKGROUND

The precise knowledge of regional anatomical details is of utmost importance specially in complex procedures such as the Ross operation. This anatomical study offers a critical approach regarding the advantages, limits, and precautions for this procedure.

METHODS

Using dissection techniques, magnifications up to x6 and nontraditional approaches, 68 fixed normal heart specimens were studied over a 2-year period. The details of surgical relevance such as the boundaries and relations of the pulmonary and aortic roots, their vascularization, and the number and distribution of the septal arteries are described.

RESULTS

The aortic and pulmonary roots include interdependent elements functioning in a coordinated manner and establishing important relations with adjacent structures. Both coronary arteries vascularize the arterial roots. The infundibular branches from the right coronary artery are larger and more constant. The septal arteries establish important relations with the pulmonary infundibulum but their contribution to its vascularization is negligible. In this series, the main septal artery was the second, showing the longest retroinfundibular course. However, no constant relation was found between this vessel and the intraventricular landmarks.

CONCLUSIONS

A novel approach was used by performing nontraditional dissections of the arterial roots and by studying their vascularization The depicted details are useful to the surgeon specializing in the Ross procedure and represent the basis for further research.

Anatomy of the muscular subpulmonary infundibulum with regard to the Ross procedure

BACKGROUND

To clarify the precise anatomical relationship of the muscular subpulmonary infundibulum.

METHODS

Eleven hearts were dissected, and microscopic sections taken through the arterial trunks of a 37-week-old fetus and of a neonate. The anatomy was also investigated during operative Ross procedures.

RESULTS

The sinotubular junctions of the pulmonary and aortic roots cross obliquely. The leaflets of the pulmonary valve are lifted away from the ventricular septum by the free-standing subpulmonary infundibulum, whereas the aortic valve is deeply wedged between the atrioventricular junctions. The muscular infundibulum spirals around the aortic root, being longest below the right-facing aortic sinus and shortest below the left. The first septal perforating artery pierces the septum below the shortest part of the infundibulum, sometimes within a millimeter of the pulmonary valvar hinge, but a muscular sleeve lifts the pulmonary leaflets from the septal musculature.

CONCLUSIONS

The pulmonary valvar leaflets are supported entirely by free-standing musculature, having no direct relationship with the ventricular septum. This makes possible the Ross procedure.