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Biomedical subjects

A Aris

Publications and source records attributed to A Aris.

At least 37 records · Page 2Linked to original sources
PubMed1996

The 20 mm Medtronic Hall prosthesis in the small aortic root.

BACKGROUND AND AIMS OF THE STUDY: The choice of prosthesis becomes crucial in the narrow aortic annulus. The 20 mm Medtronic Hall valve has a reduced sewing ring that fits in an annulus where only a 19 mm valve would fit. This study assesses the hemodynamic performance of this prosthesis at rest and at exercise, and compares it with two 19 mm mechanical prostheses. MATERIALS AND METHODS: Forty-two patients were studied by Doppler echocardiography, a mean of 34 months following surgery. Twenty-six had a 19 mm prosthesis implanted (12 standard St. Jude Medical and 14 Monostrut valves) and 16 had a 20 mm Medtronic Hall. Parameters studied were peak velocity and transvalvular gradient, both at rest and at exercise, effective orifice area and valve index. RESULTS: No differences were found between the two 19 mm valves, but when compared with the Medtronic Hall valve at rest, this valve showed significantly lower peak velocity and gradient (2.9 vs. 3.3 m/sec, p < 0.01, and 17 vs. 23 mmHg, p < 0.003, respectively) and higher effective orifice area and valve index (1.3 vs. 1.0 cm2, p < 0.01 and 0.81 vs. 0.62 cm2, p < 0.006, respectively). There were also significant differences under exercise. CONCLUSIONS: The 20 mm Medtronic Hall prosthesis shows a significantly better hemodynamic performance, both at rest and under exercise, than other, 19 mm mechanical prostheses and represents a superior choice in valve replacement with a small aortic root.

Aged↗
PubMed1994

Retrograde strut embolization in a fractured Björk-Shiley mitral prosthesis.

The case of the minor strut fracture of a Björk-Shiley convexo-concave mitral valve, with retrograde embolization to a pulmonary vein is presented. Migration probably occurred during ventricular systole and the strut became anchored to the pulmonary vein wall. The patient underwent emergency mitral valve replacement with event free recovery. The strut was located by computed tomography postoperatively, and it has remained in the same location for over one and a half years.

Emergencies↗
PubMed1993

Cardiopulmonary bypass in HIV-positive patients.

To prove the hypothesis that cardiopulmonary bypass may accelerate the development of acquired immunodeficiency syndrome (AIDS) in the human immunodeficiency virus carrier, the clinical course of 40 patients positive for human immunodeficiency virus who underwent cardiac operations between 1986 and 1992 was analyzed, especially in regard to the progression to AIDS. Mean age was 30 years (range, 19 to 61 years). Thirty-four patients (85%) were intravenous drug abusers; in 4 (10%) transmission of infection was sexual, and in 2 (5%) it was through a contaminated blood transfusion. Valve procedures were performed in 38 patients (95%), mostly for endocarditis in drug addicts. Hospital mortality was 20% (8 patients). The 32 survivors have been followed up a mean of 21 months (range, 4 months to 6 years). Four patients (12.5%) experienced progression to AIDS during the follow-up period. Actuarial progression to AIDS is 5% (+/- 5%) at 1 year, 20% (+/- 10%) at 2 years, and 40% (+/- 19%) at 5 years. There have been 8 late deaths (5 due to recurrent endocarditis, 2 due to AIDS, and 1 due to overdose). Actuarial survival is 79% (+/- 8%) at 1 year, 60% (+/- 11%) at 2 years, and 48% (+/- 14%) at 5 years. The results indicate that progression to AIDS in the patient positive for human immunodeficiency virus is not accelerated by the use of cardiopulmonary bypass. The poor prognosis in these patients is mainly related to the particular pathological conditions that often affect the drug addict population.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Subacute cardiac rupture: repair with a sutureless technique.

Thirteen patients with ages between 53 and 74 years had development of free wall left ventricular rupture after a myocardial infarction (mean interval, 3.8 days). All patients showed clinical signs of cardiac tamponade. Diagnosis was established by bedside multiple pressure monitoring and echocardiography, which showed pericardial effusion with compression of the right ventricle. Cardiac catheterization was not performed. A new surgical technique was employed for the repair. After the pericardium was opened and cardiac tamponade was relieved, the myocardial tear was identified. A Teflon patch was applied over the area and glued to the heart surface with a surgical glue (cyanoacrylate). Cardiopulmonary bypass was not used except in a patient with a posterior tear. The method was consistently effective in controlling bleeding from the myocardial tear. All patients survived the operation and were discharged from the hospital a mean of 15 days after the operation. Follow-up extending up to 5 years (mean, 26 months) shows a 100% survival, 11 asymptomatic patients, and 2 patients with mild exertional angina. The technique is a simple, effective, and safe method for repair of subacute cardiac rupture and obviates the need for suturing on an infarcted ventricle.

Aged↗
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↗