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Biomedical subjects

D M Nicoloff

Publications and source records attributed to D M Nicoloff.

At least 55 records · Page 3Linked to original sources
PubMed1980

Accessory flaplike tissue causing ventricular outflow obstruction.

In three cases, two in children and one in a young adult, ventricular outflow obstruction was caused by a valvelike flap of accessory endocardial tissue. The angiocardiographic feature was that of a narrow radiolucent, crescent-shaped or linear filling defect corresponding to the site of obstruction. Resection of the accessory tissue was performed in each case at the time of correction of associated conditions. In one case (a woman 20 years of age) the obstructing membrane was in the outflow tract of the right ventricle, and a ventricular septal defect was associated. In each of the other two cases the outflow tract of the left ventricle was the site of obstruction. In one (a 14-month-old boy), an ostium primum type of atrial septal defect and cleft mitral valve were associated; in the remaining case (a 7-year-old boy) complete transposition and ventricular septal defect were also present. In the latter case a Mustard procedure was performed and was followed by death. Successful results were obtained in the first two patients.

Adult↗
PubMed1979

Pulmonary valve replacement with a porcine aortic heterograft.

Pulmonary valve replacement is an uncommon surgical procedure, yet lifesaving when performed under the appropriate circumstances. The patient reported on here had the classic indications for valve replacement: increased pulmonary vascular resistance and associated pulmonary valve incompetence following repair of a congenital heart defect resulting in right heart failure and secondary tricuspid insufficiency. A review of the literature provides the basis for the decision to replace the pulmonary valve with a glutaraldehyde-preserved porcine heterograft.

Animals↗
PubMed1979

Pulmonary artery banding: long-term results in 63 patients.

Sixty-three patients who underwent banding of the pulmonary artery between 1968 and 1975 were studied. Mortality among patients who underwent the banding procedure was 22%, and among those with ventricular septal defect it was 7%. Thirty-eight of the 49 survivors of the banding procedure were investigated for abnormalities of the pulmonary outflow tract caused by the band. Seventy-one percent of these 38 patients had an identifiable abnormality of the pulmonary valve or artery. These complications occurred more frequently in patients banded at a very young age (less than 2 months old) and in patients in whom the band was in place more than two years. Corrective operations have been performed in 24 of the 49 patients who survived banding. Seventy-six percent of the patients with ventricular septal defect survived corrective operation, while only 29% of the patients with more complex lesions survived.

Age Factors↗
PubMed1979

The Bezold reflex: a special case of the left ventricular mechanoreceptor reflex.

Our previous finding that increasing myocardial contractility caused reflex systemic hypotension, the left ventricular (LV) mechanoreceptor reflex, suggested that the classical Bezold reflex (systemic hypotension and bradycardia after intracoronary administration of veratrum alkaloids) may be initiated by these same LV mechanoreceptors. In our working LV preparation with the coronary and systemic circulations isolated and perfused separately, intracoronary injection of veratrum alkaloids, like that of catecholamines or ouabain, had a positive inotropic effect which produced the hypotensive response typical of the LV mechanoreceptor reflex. To test directly if veratridine's positive inotropic effect initiates the Bezold reflex, verapamil, which blocks the slow Ca(2+) channels of myocardial cells but leaves intracardiac nerves unaffected, was injected by the intracoronary route to prevent the increased contractility from intracoronary injection of veratridine which also abolished the reflex hypotension, demonstrating conclusively that increasing myocardial contractility and thereby activating LV mechanoreceptors but not chemoreceptors initiates the Bezold reflex. Contrariwise, decreasing contractility or cardiac asystole by administration of tetrodotoxin, verapamil, or EDTA resulted in an increase in the systemic resistance, indicating that changes in the magnitude of the stimulus initiating the LV mechanoreceptor reflex (i.e., changes in myocardial contractility) lead to directionally opposite changes in peripheral resistance, as in the sino-aortic mechanoreflexes. Thus, it is concluded that the Bezold reflex is a special case of the LV mechanoreceptor reflex. The latter, by means of feedback mechanisms, functions normally by continuously matching the peripheral resistance to the LV contractile state so as to maintain the arterial pressure constant, thereby playing an important role in blood pressure regulation.

Animals↗
PubMed1979

A new cardiac prosthesis: the St. Jude Medical cardiac valve: in vivo results.

The St. Jude Medical cardiac valve prosthesis is a low profile, lightweight, bi-leaflet, central-flow device constructed entirely of pyrolytic carbon. In vivo testing was performed in 24 cows in which the tricuspid valve (n = 14) or mitral valve (n = 10) was replaced by a St. Jude Medical prosthesis with a 26 mm tissue annulus diameter. Eight animals died in the operative period. The 16 surviving animals were sacrificed at 4, 8, 12, or 18 weeks. There were no valve-related deaths nor mechanical valve failures. Anticoagulation was not used in the postoperative period during which time monthly laboratory parameters were obtained including hemoglobin, hematocrit, white cell count, red cell count and indices, lactic acid dehydrogenase, serum haptoglobin, and, additionally at sacrifice, platelet and red cell morphology. Values indicated this prosthesis did not cause hemolysis. At sacrifice the pulmonary arterial tree and peripheral organs showed no evidence of thromboemboli. There was smooth endocardial ingrowth on all valve sewing rings. One valve had thrombus formation on the valve sewing ring. Nine animals were anesthetized prior to sacrifice and underwent open cardiac catheterization. Ventriculography (n = 6) showed minimal transvalvar reflux, and atriograms (n = 6) demonstrated central flow. Transvalvar gradients were 0 to 22 mm Hg (n = 9). One valve of an 18-week tricuspid implant was examined for wear; valve life was calculated to be greater than 2500 years. These data in conjunction with in vitro test results justify clinical trial of the St. Jude Medical prosthesis.

Animals↗
PubMed1979

Pulmonary artery banding in infants with complete atrioventricular canal.

Management of symptomatic atrioventricular canal (AVC) in infancy may be difficult. Between July, 1969, and September, 1977, 31 infants with complete AVC presented in congestive heart failure (CHF) to the University of Minnesota Hospitals. Fifteen of these patients have responded to medical management and have been followed as outpatients. The other 16 patients remained in CHF. Six of them died of persistent heart failure within 4 months. The other 10 infants, aged 3 weeks to 1 year (mean 4 months), underwent pulmonary artery banding and seven survived operation. One of the survivors died with apparent pneumonia 1 month postoperatively. Each of the remaining six patients, who have been followed for 9 months to 9 years, had minimal mitral insufficiency and a large ventricular shunt. The three patients dying after banding had significant mitral insufficiency. We believe that pulmonary artery banding is an effective palliative procedure for infants with complete AVC and CHF who have large ventricular shunts and minimal mitral insufficiency.

Angiocardiography↗
PubMed1979

St. Jude Medical cardiac valve prosthesis: in vitro studies.

The St. Jude Medical cardiac valve prosthesis is an all-pyrolitic carbon, bileaflet, low profile, central flow device. Prior to clinical use on intensive program of in vitro and in vivo testing was undertaken. Simulated radiographic studies determined that the tungsten impregnation needed to make the valve leaflets radiopaque was 0.013 inch. Steady-state flow and pulse duplicator studies demonstrated a high ratio of flow orifice to tissue anulus diameter with low transvalvular pressure gradients. Regurgitation was found to be acceptable. Flow visualization revealed central flow through all three flow orifices with minimal turbulence and vorticeal current formation. In vitro comparison with other available cardiac valve devices of various sizes demonstrated superior hemodynamic performance of the St. Jude Medical cardiac valve.

Aortic Valve↗
PubMed1978

Hemodynamic evaluation of Lillehei-Kaiser and Starr-Edwards prosthesis.

The central-flow low profile disc-valve prosthesis has been offered as an alternative to ball- and tissue-valve prostheses. Extensive laboratory investigation with both pulse duplicator and experimental animals has been reported for the Lillehei-Kaster prosthesis. A series of patients receiving this prosthesis underwent postoperative cardiac catheterization to better define the hemodynamic function of this prosthesis in vivo. Because of the variations in reports of hemodynamic data from various institutions, the results of post-operative studies in an earlier group of patients with Starr-Edwards prostheses were used as a standard for comparison. Good hemodynamic function was found with the pivoting-disc prosthesis in all but the smallest valve sizes. Lillehei-Kaster and early model Starr-Edwards prostheses with equivalent tissue annulus dimensions were found to have nearly equal valve areas in vivo in the aortic position. The Lillehei-Kaster mitral valves provided larger areas than Starr-Edwards prostheses in large tissue annulus sizes.

Evaluation Studies as Topic↗
PubMed1978

Development of a practical membrane lung system.

The purpose of this study was to evaluate a compact, single-pump membrane oxygenator system designed for both short-term open-heart procedures and long-term extracorporeal support. Work was directed at developing a compatible, disposable venous reservoir, fabricating a compact mounting board, determining acceptable priming volumes, and establishing safe and effective modes of setup and operation. Ten adult baboons undergoing total cardiopulmonary autotransplantation as part of a separate study were operated on using a 1.5 m2 Kolobow spiral-coil membrane system. Blood gases, oxygen transfer, extracorporeal blood flows, priming volume, and setup times were determined. In addition, 3 infant and 6 adult human subjects undergoing cardiac operations in which spiral-coil membranes of various sizes were used were also similarly studied. The data and experience from these studies suggest that the spiral-coil membrane system utilized is safe and effective in procedures requiring short-term cardiopulmonary bypass.

Adolescent↗
PubMed1978

Placement of pericardial drainage tube for the treatment of pneumopericardium in the neonate.

A method for resolving the life-threatening complication of neonatal pneumopericardium is described. In patients suspected of having this complication, needle aspiration of the pericardial sac should be performed to confirm the diagnosis. Then a tube should be inserted directly into the sac, attached to continuous-suction drainage, and allowed to remain in place until positive end-expiratory pressure is discontinued. The technique has not been associated with morbidity, mortality, or recurrence of pneumopericardium.

Drainage↗
PubMed1978

Bronchioloalveolar cell carcinoma of the lung: a clinicopathological study.

Thirty-nine patients with bronchioloalveolar carcinoma were reviewed. The primary lung tumor from 27 patients was examined and divided by histological criteria into three categories. The type 1 pattern was associated with a mean survival of 4.7 years. A mean survival of 3.8 years was attained in patients with type 2. Patients with the type 3 pattern had an average survival of 1.4 years. There was a statistically significant difference in survival when types 1 and 2 together were compared with type 3 (rho less than 0.05). Another statistically significant finding was a mean survival of 5.2 years in patients with negative lymph nodes after surgical resection and a 2.2 year mean survival in patients with positive nodes. The tumor histology of bronchioloalveolar carcinoma should be examined carefully to obtain helpful information in predicting survival. We recommend that these tumors be classified as well-differentiated or poorly differentiated bronchioloalveolar carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1978

Abdominal aortic aneurysm with rupture into inferior vena cava associated with horseshoe kidney.

The first patient with an abdominal aortic aneurysm with rupture into the inferior vena cava associated with a horseshoe kidney is reported. Rupture of an aortic aneurysm into the inferior vena cava with formation of an aortocaval fistula has been reported in 100 patients. Aortic aneurysm in combination with horseshoe kidneys has been described in 34 patients. The diagnosis was made by an abdominal aortogram. The patient's preoperative condition was characterized by circulatory and renal failure subsequent to the development of a large aortocaval fistula. Operative repair was performed by dividing and rotating the kidney, dividing a renal polar artery, incising the aneurysm, and over-sewing the fistula from within. The patient's postoperative course was complicated by renal failure and sepsis and he died two months later. It is essential to preserve renal function in patients with this combination of anomalies.

Aorta, Abdominal↗
PubMed1978

Ball variance and fracture of mitral valve prosthesis causing recurrent thromboemboli.

This report documents the ninth case of ball variance in a Starr-Edwards Model 6000 mitral prosthesis occurring 10 years, 9 months after implantation. It is the fourth case of fracture of a mitral ball of any type. As this case illustrates, the presence of ball variance in the mitral position may be subtle. One must carry a high index of suspicion if the diagnosis is to be made and treatment undertaken before catastrophic events take place. The incidence of ball variance is likely to increase with the length of implantation. We recommend surgical replacement of the defective prosthesis immediately upon confirmation of diagnosis.

Adult↗