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Biomedical subjects

William C Roberts

Publications and source records attributed to William C Roberts.

At least 19 recordsLinked to original sources
PubMed2006

The heaviest known operatively-excised aortic valve.

A 60-year-old man whose operatively excised stenotic and regurgitant aortic valve weighed nearly 15 g, approximately 30 times the normal weight in an adult, is described. To the investigators' knowledge, this is the heaviest aortic valve ever encountered in a human being.

Aortic Valve↗
PubMed2005

Frequency by decades of unicuspid, bicuspid, and tricuspid aortic valves in adults having isolated aortic valve replacement for aortic stenosis, with or without associated aortic regurgitation.

BACKGROUND: Aortic valve stenosis (with or without aortic regurgitation and without associated mitral stenosis) in adults in the Western world has been considered in recent years to most commonly be the result of degenerative or atherosclerotic disease. METHODS AND RESULTS: We examined operatively excised, stenotic aortic valves from 932 patients aged 26 to 91 years (mean+/-SD, 70+/-12), and none had associated mitral valve replacement or evidence of mitral stenosis: A total of 504 (54%) had congenitally malformed valves (unicuspid in 46 [unicommissural in 42; acommissural in 4] and bicuspid in 458); 417 (45%) had tricuspid valves (either absent or minimal commissural fusion); and 11 (1%) had valves of undetermined type. It is likely that the latter 11 valves also had been congenitally malformed. Of the 584 men, 343 (59%) had either a unicuspid or a bicuspid valve; of the 348 women, 161 (46%) had either a unicuspid or a bicuspid aortic valve. CONCLUSIONS: The data from this large study of adults having isolated aortic valve replacement for aortic stenosis (with or without associated aortic regurgitation) and without associated mitral stenosis or mitral valve replacement strongly suggest that an underlying congenitally malformed valve, at least in men, is more common than a tricuspid aortic valve.

Adult↗
PubMed2004

Relation of weights of operatively excised stenotic aortic valves to preoperative transvalvular peak systolic pressure gradients and to calculated aortic valve areas.

OBJECTIVES: The purpose of this study was to correlate the weights of operatively excised stenotic aortic valves to preoperative transvalvular peak systolic gradients and to calculated aortic valve areas. BACKGROUND: No previous publication has correlated the weights of stenotic aortic valves to the transvalvular gradients or to the calculated aortic valve areas. METHODS: We weighed operatively excised stenotic aortic valves in 324 adults who had undergone preoperative left-sided cardiac catheterization. RESULTS: As the weights of the operatively excised stenotic aortic valves increased (from <1 g to >6 g), the average transvalvular peak systolic pressure gradients progressively increased. For any valve weight, in general, the women had higher average transvalvular gradients (p </= 0.005) and lower average valve areas (p </= 0.008) than did the men. Correlation between aortic valve weight and transvalvular gradient improved further when gender was taken into account. CONCLUSIONS: Preoperative transvalvular peak systolic pressure gradients across stenotic aortic valves correlate better with the weights of the operatively excised valves than do the calculated valve areas.

Adult↗
PubMed2004

Weights of individual cusps in operatively-excised congenitally bicuspid stenotic aortic valves.

We weighed each cusp separately in 200 operatively excised stenotic congenitally bicuspid aortic valves. It was found in 152 patients (76%) that the cusps differed (by > 0.2 g) in weight and in 48 patients (24%) that the cusps were of similar (a < or = 0.2 g difference) weights. In 161 of the 200 patients (80%), raphes were present in 1 cusp; the raphe and nonraphe cusps differed in weight in 120 patients (74%), with the raphe cusps being larger in 89 patients (74%), and were of similar weights in 41 patients (26%). Of the 39 patients with raphes in neither cusp, 32 cusps (82%) differed in weight and 7 (18%) were of similar weights. The weight of each cusp differed more as the total valve weights increased.

Adult↗
PubMed2004

Weights of individual cusps in operatively-excised stenotic three-cuspid aortic valves.

We weighed each cusp separately in 260 operatively excised stenotic 3-cuspid aortic valves. All 3 cusps differed (by > 0.1 g) in weight in 69 patients (26%); all 3 cusps were similar (a < or = 0.1 g difference) in weight in 33 patients (13%); and 1 cusp differed from either of the other 2 cusps, which were similar in weight, in 158 patients (61%). The weight differences appeared to be caused by differing quantities of calcium on the aortic surfaces of the cusps.

Adult↗