The books and articles devoted to the anatomy of the aortic valvar complex are numerous. Until now, however, little consideration has been given to understanding the anatomy with percutaneous valvar replacement in mind. It is axiomatic that knowledge of the anatomy of the valve is fundamental in understanding key principles involved in valvar replacement. Such an appreciation of the anatomy helps better understand the optimal positioning for the prosthetic valve within the root of the aorta with respect to the coronary arteries, mitral valve, and the conduction system and may circumvent complications that can arise during its implantation. In this review, therefore, we describe the anatomy of the trifoliate aortic valvar complex and its implications for percutaneous valvar replacement.

Background—: Recent transcatheter aortic valve replacement studies have raised concerns about adverse cerebrovascular events. The etiopathology of the embolized material is currently unknown. Methods and Results—: A total of 40 patients underwent transcatheter aortic valve replacement with the use of a dual filter–based embolic protection device (Montage Dual Filter System, Claret Medical, Inc). Macroscopic material liberated during the transcatheter aortic valve replacement procedure was captured in the device filter baskets in 30 (75%) patients and sent for histopathologic analysis. The captured material varied in size from 0.15 to 4.0 mm. Amorphous calcified material (size, 0.55–1.8 mm) was identified in 5 patients (17%). In 8 patients (27%), the captured material (size, 0.25–4.0 mm) contained valve tissue composed of loose connective tissue (collagen and elastic fibers) with focal areas of myxoid stroma, with or without coverage by endothelial cells and intermixed with fibrin. In another 13 (43%) patients, collagenous tissue, which may represent elements of vessel wall and valvelike structures, was identified. In 9 patients (30%), thrombotic material was intermixed with neutrophils (size, 0.15–2.0 mm). Overall, thrombotic material was found in 52% of patients, and tissue fragments compatible with aortic valve leaflet or aortic wall origin were found in 52% (21/40) of patients. Conclusions—: Embolic debris traveling to the brain was captured in 75% of transcatheter aortic valve replacement procedures where a filter-based embolic protection device was used. The debris consisted of fibrin, or amorphous calcium and connective tissue derived most likely from either the native aortic valve leaflets or aortic wall.

OBJECTIVE: The predictive value of microalbuminuria (MA) in children with type 1 diabetes has not been defined. We describe the natural history of MA in a large cohort of children recruited at diagnosis of type 1 diabetes. RESEARCH DESIGN AND METHODS: Between 1985 and 1996, 514 children (279 male) who developed type 1 diabetes before the age of 16 years (91% of those eligible from a region where ascertainment of new cases is 95%) were recruited for a longitudinal study with central annual assessment of HbAlc and albumin excretion (three urine samples). Dropout rates have been < 1% per year, and 287 children have been followed for > 4.5 years. RESULTS: MA (defined as albumin-to-creatinine ratio > or = 3.5 and > or = 4.0 mg/mmol in boys and girls, respectively) developed in 63 (12.8%) and was persistent in 22 (4.8%) of the subjects. The cumulative probability (based on the Kaplan-Meier method) for developing MA was 40% after 11 years. HbAlc was worse in those who developed MA than in others (mean difference +/- SEM: 1.1% +/- 0.2, P < 0.001). In subjects who had been 5-11 years of age when their diabetes was diagnosed, the appearance of MA was delayed until puberty, whereas of those whose age was < 5 years at diagnosis of diabetes, 5 of 11 (45%) developed MA before puberty. The adjusted proportional probability (Cox model) of MA was greater for female subjects (200%), after pubertal onset (310%), and with greater HbAlc (36% increase for every 1% increase in HbAlc). Despite earlier differences based on age at diagnosis of diabetes (< 5, 5-11, and > 11 years), the overall cumulative risks in these groups were similar (38 vs. 29 vs. 39%, respectively) after 10 years' duration of diabetes. CONCLUSIONS: Prepubertal duration of diabetes and prepubertal hyperglycemia contribute to the risk of postpubertal MA. The differences in rates of development of MA relating to HbAlc, sex, and age at diagnosis relative to puberty may have long-term consequences for the risk of subsequent nephropathy and for cardiovascular risk.

To evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection. Multislice computer tomography annulus diameters [minimum: D_min; maximum: D_max; mean: D_mean = (D_min + D_max)/2; mean from circumference: D_circ; mean from surface area: D_CSA] were measured in 75 patients referred for percutaneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n = 22; 29 mm: n = 28). D_min and D_max differed substantially [mean difference (95% CI) = 6.5 mm (5.7–7.2), P < 0.001]. If D_min were used for sizing 26% of 75 patients would be ineligible (annulus too small in 23%, too large in 3%), 48% would receive a 26 mm and 12% a 29 mm CRS. If D_max were used, 39% would be ineligible (all annuli too large), 4% would receive a 26 mm, and 52% a 29 mm CRS. Using D_mean, D_circ, or D_CSA most patients would receive a 29 mm CRS and 11, 16, and 9% would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing based on D_CSA and D_mean (76%, 74%), but undersizing occurred in 20 and 22% of which half were ineligible (annulus too large). Eligibility varied substantially depending on the sizing criterion. In clinical practice both under- and oversizing were common. Industry guidelines should recognize the oval shape of the aortic annulus.