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Biomedical subjects

A Aris

Publications and source records attributed to A Aris.

At least 19 recordsLinked to original sources
PubMed1992

The Monostrut Björk-Shiley valve. Seven years' experience.

The results of cardiac valve replacement with the Monostrut Björk-Shiley prosthesis (Shiley, Inc., Irvine, Calif.) during a 7-year period are presented. A total of 984 valves were implanted in 820 patients from May 1983 to April 1990. Aortic valve replacement was performed in 378 patients, mitral replacement in 294, and multiple replacement in 148. In addition, 180 patients (22%) underwent associated procedures. Mean age was 52.6 +/- 11 years. Operative (30 days) mortality was 5.9% (49 patients): 3.9% (15 patients) for aortic, 7.8% (23 patients) for mitral, and 7.4% (11 patients) for multiple valve replacement. All patients were given long-term anticoagulation therapy. Follow-up was 99% complete (eight patients were lost to follow-up), with a closing interval of 3 months, and totaled 2422 patient-years. Valve-related complications, expressed as percentage event-free (+/- standard error) at seven years were as follows: structural deterioration, 100%; nonstructural dysfunction, 98.3% +/- 0.6%; thromboembolism, 90.2% +/- 1.7%; anticoagulant-related hemorrhage, 88.7% +/- 2.8%; and prosthetic valve endocarditis, 98.1% +/- 0.8%. There were no cases of valve thrombosis. Actuarial survival (free from operative, valve-related, and sudden death) was 88.4% +/- 1.2% at 7 years. Freedom from reoperation was 96.8% +/- 0.1%. Probability of being free from all valve-related morbidity and mortality was 70% +/- 3%, and 708 (93%) of the survivors were in New York Heart Association class I or II. Serial Doppler echocardiograms were done prospectively in 243 patients (with 154 aortic and 120 mitral prostheses), both postoperatively and at regular intervals up to 3 years. Mean prosthetic gradients ranged from an average of 20.9 to 7 mm Hg in the aortic prostheses (21 to 29 mm) and from 6.1 to 4.8 mm Hg in the mitral prostheses (25 to 31 mm). The gradients in each patient did not change significantly during the follow-up period. Our 7 year's experience with the Monostrut valve shows a low rate of valve-related complications, a durable design, and good hemodynamic and functional results.

Actuarial Analysis↗
PubMed1992

Hemodynamic effects of prostaglandin E1 and isoproterenol early after cardiac operations for mitral stenosis.

Patients with mitral stenosis and some degree of right ventricular failure may benefit from inotropic or pulmonary vasodilator drugs in the early postoperative period. Thirty patients undergoing an operation for mitral stenosis were randomized into three groups. In group I (n = 10), isoproterenol (5 micrograms/kg/min) was started in the immediate postoperative period. In group P (n = 10), prostaglandin E1 (0.08 microgram/kg/min) was given, and in group C, the control group (n = 10), no drugs were used. After the operation and before drug therapy was begun, basal measurements of cardiac index, mean pulmonary arterial and mean arterial pressures, and pulmonary vascular resistance were taken. Measurements were repeated at 6, 12, and 24 hours. Mean measurements of cardiac index (basal up to 24 hours) were as follows: 1.39 +/- 0.3, 1.92 +/- 0.4, 2.4 +/- 0.5, and 2.34 +/- 0.3 L/min/m2 for group C; 1.54 +/- 0.5, 2.64 +/- 0.4, 2.68 +/- 0.7, and 2.2 +/- 0.6 L/min/m2 for group I, and 1.57 +/- 0.3, 2.2 +/- 0.6, 2.72 +/- 0.7, and 2.27 +/- 0.4 L/min/m2 for group P (p less than 0.05 between groups C and I at 6 and 12 hours). Mean pulmonary artery pressures were as follows: 19.5 +/- 3.2, 24.8 +/- 7, 27.7 +/- 7.3 and 28.8 +/- 5.7 mm Hg in group C; 21.4 +/- 8.7, 25.7 +/- 7.2, 26.4 +/- 7, and 29.4 +/- 8.6 mm Hg in group I, and 19.1 +/- 4, 19.2 +/- 3, 20.4 +/- 6, and 20.7 +/- 5 mm Hg in group P (p less than 0.05, group P versus groups C and I at 6, 12, and 24 hours). Mean pulmonary vascular resistances were as follows: 3.9 +/- 2.4, 3.9 +/- 1, 3.36 +/- 2, and 3.2 +/- 1.4 Wood units in group C; 4.84 +/- 4, 3.37 +/- 2.2, 3.69 +/- 3, and 4.69 +/- 4.1 Wood units in group I, and 3.29 +/- 1.3, 1.71 +/- 0.5, 1.61 +/- 0.5, and 1.96 +/- 0.8 Wood units in group P (p less than 0.05, group P versus groups C and I at 6, 12, and 24 hours). There was no difference in mean systemic arterial pressure among the three groups. Our results indicate that patients subjected to mitral valve operations have a low cardiac index. Isoproterenol increases cardiac index but has little effect on pulmonary resistance. At low doses, prostaglandin E1 effectively decreases pulmonary vascular resistance without altering systemic arterial pressure or heart rate.

Alprostadil↗
PubMed1989

Fertility in a case of progeria.

A 32-year-old woman with Hutchinson-Gilford disease (progeria) is described. The absence of complete sexual maturation has been considered characteristic of the syndrome, but this woman delivered a normal child at the age of 23.

Adult↗
PubMed1988

Long-term results of mitral valve surgery in patients with severe pulmonary hypertension.

Mitral valve surgery was performed in 88 patients with severe pulmonary hypertension (average systolic pulmonary artery pressure, 94.7 +/- 22 mm Hg; range, 70-180 mm Hg) over a 10-year period. Sixty-four patients (73%) were in New York Heart Association Functional Class III or IV. There were 64 valve replacements and 24 open mitral commissurotomies. Operative mortality was 5.6% (5 patients) and was not related to the degree of pulmonary hypertension, surgical procedure performed, or type of valve lesion. A 100% follow-up was obtained, ranging from nine months to 10 years, with a mean of 44 months. Six late cardiac deaths (7.2%) occurred, 5 in patients with valve replacement and 1 in a patient who underwent a commissurotomy. Actuarial survival was 86 +/- 3% at five years and 83 +/- 4% at 10 years. Fourteen patients underwent right ventricular catheterization a mean of 24 months following operation. Systolic pulmonary artery pressure had decreased from a mean preoperative value of 101 +/- 22 to 40.5 +/- 7 mm Hg (p less than 0.001). Cardiac index increased by 55% of the preoperative values. Functional status improved markedly; 71 survivors (93%) were in New York Heart Association Class I or II. These results indicate that, in patients with mitral valve lesions and severe pulmonary hypertension, (1) surgical procedures can be performed with an acceptable operative mortality; (2) excellent long-term survival and functional results can be obtained; and (3) pulmonary hypertension decreases significantly after operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1988

Clinical and hemodynamic results of cardiac valve replacement with the Monostrut Björk-Shiley prosthesis.

Between May 1983 and April 1986, 318 patients underwent cardiac valve replacement with the Monostrut Björk-Shiley prosthesis. There were 136 aortic valve replacements, 128 mitral valve replacements, and 54 multiple replacements. A total of 373 valves were implanted. Associated procedures were done in 79 (25%) of the patients. Hospital (30-day) mortality rate was 5.6% (18 patients): 2.9% (n = 4) after aortic, 7.8% (n = 10) after mitrals and 7.4% (n = 4) after multiple valve replacement. Follow-up was obtained in all 300 operative survivors, for a total of 500 patient-years (mean 18 months). Actuarial survival rate, excluding operative deaths, at 4 years was 94.7% +/- 1.5% (mean +/- standard error of the mean). There were 16 thromboembolic episodes (3.2/100 patient-years). Freedom from all valve-related complications was 87% +/- 2.4% at 3 1/2 years. Neither valve thrombosis nor structural failure has been observed. Eighty percent of the patients are in New York Heart Association functional class I. Forty-two patients (26 with aortic and 16 with mitral valve replacement) underwent cardiac catheterization a mean of 6 1/2 months after the operation. In the aortic position, peak gradients were an average of 6.9 +/- 1.2 mm Hg. Mean systolic gradients were 12.4 +/- 6.3 mm Hg and did not increase with exercise. In the mitral position, end-diastolic gradients were an average of 2.1 +/- 2 mm Hg and mean gradients, 5.9 +/- 2 mm Hg. Discharge coefficient (estimated orifice area/geometric area) was 0.63 +/- 0.2 for the aortic and 0.53 +/- 0.2 for the mitral prostheses. Disc opening was maximal in most patients. These results indicate that the Monostrut prosthesis has a low rate of thromboembolic events, no structural failures or thrombotic obstructions and excellent hemodynamic performance, especially in the small aortic sizes (discharge coefficient for 19 and 21 mm valves, 0.77).

Adolescent↗
PubMed1987

Patency of internal mammary artery grafts in no-flow situations.

We report two cases in which an internal mammary artery graft was found to be nonfunctional in the early postoperative period, but repeat catheterization at 6 months revealed the graft to be patent. These two cases substantiate that closure of an internal mammary artery graft may be reversible.

Cardiac Catheterization↗
PubMed1986

Arterial line filtration during cardiopulmonary bypass. Neurologic, neuropsychologic, and hematologic studies.

One hundred patients who underwent elective cardiac operations were randomized into two groups. Group 1 had a 20 micron nylon screen filter in the arterial line. In Group 2 no filter was used in the arterial line. Neurologic and neuropsychologic examination of the patients was performed with seven psychometric tests of the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale. These tests were conducted before and a mean of 10 days after the operation. Platelet counts and hemoglobin and total protein levels were measured at the onset and at the end of cardiopulmonary bypass. Two patients died during their hospital stay. Neurologic damage with focal signs was found in the postoperative examination in six patients (three in each group). Twenty-eight patients (28.5%) exhibited signs of mild cerebral dysfunction as assessed by the presence of archaic (primitive) reflexes. Fifteen were in Group 1 and 13 in Group 2 (no significant difference). Sixty patients (61%) had decrements greater than one standard deviation in at least one of the three tests that showed most decreased postoperative scores. There were 32 in Group 1 and 28 in Group 2 (no significant difference). When each test was analyzed individually, there were no significant differences between the two groups. Platelet counts decreased, during cardiopulmonary bypass, a mean of 33% in Group 1 and 34.5% in Group 2 (no significant difference). Both hemoglobin and total protein levels remained virtually unchanged. These results indicate that the addition of a small-pore filter in the arterial line does not prevent the neurologic and neuropsychologic disturbances frequently encountered after cardiopulmonary bypass. The filter itself does not appear to have a direct effect on the blood components. Routine use of an arterial line filter remains questionable.

Arteries↗
PubMed1985

Hemodynamic evaluation of the integral monostrut Björk-Shiley prosthesis in the aortic position.

Between May, 1983, and November, 1984, the new integral monostrut Björk-Shiley prosthesis was used for aortic valve replacement in 62 patients. The prosthesis is machined from a solid piece of cobalt alloy and has no welded joints. The traditional U-shaped outlet strut has been replaced by a projecting metal finger that holds the disc in place. The disc opens to 70 degrees and is convexoconcave. Successful transseptal heart catheterization was performed in 23 patients an average of 6 months following operation to evaluate the hemodynamic performance of the prosthesis. The mean peak-to-peak gradient was 7.73 +/- 7.49 mm Hg (+/- standard deviation). In five valves it was 0, and in only three was it higher than 15 mm Hg. Significant peak gradients were directly related to the valve index (valve area/body surface area). Mean systolic gradient at rest was 12.7 +/- 6.27 mm Hg and did not increase after exercise. Effective orifice areas were adequate, and the discharge coefficient ranged from 0.77 for the 21-mm prosthesis to 0.48 for the 29-mm prosthesis. Minimal regurgitation, which was washed out on the next systole, was observed with all sizes of the prosthesis. Disc opening was maximal (70 degrees) in all but one of the observed instances. Longer clinical follow-up is required, but the new integral monostrut Björk-Shiley prosthesis, with its important design changes and excellent hemodynamic performance, appears to be a promising aortic valve substitute.

Adult↗
PubMed1984

Combined aortocoronary bypass and intraoperative transluminal angioplasty in left main coronary artery disease.

Transaortic intraluminal angioplasty of the left main coronary artery by Grüntzig's technique has been used intraoperatively in 4 patients who underwent multiple aortocoronary bypasses. Angiographic and clinical results were excellent in 3 of them. It is suggested that this combined technique be used to obtain more complete revascularization at the time of coronary artery bypass. The technique is easy to perform without x-ray facilities in the operating room, and it seems reasonable to assume that it may improve the myocardial blood supply of those areas irrigated by small arteries originating between the stenosed main trunk and other subsequent lesions.

Angina Pectoris↗
PubMed1983

Clinical evaluation of a new temporary pacemaker wire.

A newly designed temporary pacemaker wire has been tested in 20 patients who underwent open-heart operations. This new device has a small tip that stays securely buried in the myocardium, thus greatly reducing the risk of accidental dislodgment. In addition, the increase in thresholds during the postoperative period is slighter than with the standard electrode.

Cardiac Surgical Procedures↗