Long-term clinical and hemodynamic evaluation of the Ionescu-Shiley pericardial xenograft heart valve

Middle Molecules in Chronic Uremic Patients Treated with Continuous Ambulatory Peritoneal Dialysis

Endogenous middle molecules (MM), which accumulate in uremia are more efficiently removed and better controlled by CAPD than by other forms of dialysis treatment. The generation rate of MM's in CAPD patients is closely related to protein intake and/or breakdown.

Two-dimensional echocardiographic assessment of complications involving the Ionescu-Shiley pericardial valve in the mitral position

The function of the Ionescu-Shiley bovine pericardial xenograft in the mitral position was investigated in 70 patients by two-dimensional echocardiography. Echocardiographic data from 21 patients with suspected bioprosthetic dysfunction and 49 patients with normal clinical findings were analyzed in a double-blind fashion. Confirmation of cardiovascular status was obtained by means of cardiac catheterization, surgery, autopsy or other techniques in 19 of the 21 symptomatic patients. Two-dimensional echocardiography correctly evaluated bioprosthetic function in 98% of the patients. Six of the seven patients with proven xenograft dysfunction demonstrated echocardiographic evidence of malfunction. There was one false negative evaluation but no false positive results. Valve dysfunction included endocarditic mass lesions, mitral regurgitation resulting from dehiscence of a leaflet or the sewing ring or mitral stenosis due to calcification or malposition of the valve. This experience indicates that two-dimensional echocardiography is useful for assessing the Ionescu-Shiley mitral bioprosthesis, particularly in those patients who develop nonspecific symptoms.

M-Mode and 2-dimensional echocardiographic characteristics of the Ionescu-Shiley valve in the mitral and aortic positions

Using M-mode and 2-dimensional (2-D) echocardiography, ultrasonic features of the Ionescu-Shiley valve were characterized. A number 23 prosthesis was placed in a saline-filled chamber and subjected to pulsatile flow. Production of a linear tear at the base of a cusp resulted in coarse fluttering in the open position, and there was a reduction in the anterior cusp slope. Partial detachment of a cusp from its stent produced high-amplitude low-frequency fluttering during ejection. Alteration of transducer position eliminated the abnormal echoes. Fourteen patients with aortic and 11 with mitral prostheses were studied. There was a close approximation of echographically determined values for the bare stent internal diameter, cusp excursion, and valve orifice diameter compared with the manufacturer's specifications. Random punctiform echoes were noted when the cusps opened. Cusp echoes were superimposed on stent echoes in 21% of patients, and a third cusp was detected in 29%. Two-dimensional echocardiograms of good quality were recorded in the vast majority of subjects. Cusp echoes were smooth and had a consistent motion in both the short and longitudinal axis. Multiple transducer positions were required to delineate prosthetic components with optimal clarity. It is concluded that (1) M-mode and 2-D echocardiography is useful in assessing Ionescu-Shiley valve function, (2) in vitro valve tears or detachment produces characteristic cusp fluttering, (3) careful attention to transducer positions is necessary to record high-quality valve images, and (4) these findings represent a data base for the longitudinal follow-up study of patients with the Ionescu-Shiley valve.