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Biomedical subjects

J R Skinner

Publications and source records attributed to J R Skinner.

At least 55 records · Page 3Linked to original sources
PubMed1984

Natural history of surgically treated ventricular aneurysm.

Forty-one patients underwent resection of a postinfarction ventricular aneurysm. Thirty-seven of them had associated saphenous vein grafting procedures (average, 2.3 grafts per patient). Thirty-five patients sustained left ventricular dysfunction preoperatively. Forty patients were followed until death or for a minimum of five years (1 was lost to follow-up), and functional status was evaluated. Hospital mortality was 12%. Twenty-four patients survived five years or longer, and 20 patients were alive after a mean follow-up of 84 months. Eighty percent of the nonsurvivors died of atherosclerosis-related events. Forty-nine percent of the patients who survived the operation sustained severe atherosclerotic events postoperatively. Only 2 of 15 nonsurvivors ever regained functional status as judged by return to work. Twelve of the 20 long-term survivors returned to work. Of those patients less than 50 years old at operation, only 17% returned to work. Preoperative left ventricular function was a significant predictor of long-term functional results of aneurysmectomy and saphenous vein grafting. All patients remained at high risk for continued events related to atherosclerotic cardiovascular disease, and only 37% returned to full-time, preoperative work status. Return to productive status was especially disappointing in patients less than 50 years old.

Adult↗
PubMed1984

A technique for immediate manual external aortic counterpulsation during cardiac surgery.

Intraaortic balloon pump counterpulsation is well established as a lifesaving measure. Aortic counterpulsation may be achieved externally as well as internally. A simple technique for manual external aortic counterpulsation during cardiovascular surgical procedures is presented. This technique is available on immediate demand and identical in effect to intraaortic balloon pumping, and it may be lifesaving in patients with acute cardiovascular decompensation since it allows time for institution of necessary emergency therapy.

Aorta↗
PubMed1984

Immediate coronary bypass following failed streptokinase infusion in evolving myocardial infarction.

Since December of 1980, 184 patients with evolving myocardial infarction (EMI) have undergone streptokinase infusion, with associated percutaneous transluminal coronary angioplasty (PTCA) in 68 patients. Emergency coronary bypass was deemed necessary in 24 of these patients. All 24 patients had severe triple-vessel disease and moderate to marked ventricular dysfunction, with eight (33%) requiring intra-aortic balloon pump (IABP) support for profound cardiac decompensation preoperatively. All 24 patients underwent immediate coronary bypass (average 4.1 grafts/patient), with four operative and two late deaths. Average postoperative blood loss was 1,453 ml, and average blood transfusion postoperatively was 8.2 units per patient. Thirteen patients had normal clotting studies immediately postoperatively, and only two patients developed frank coagulopathy (hyperfibrinolysis). Four patients required reexploration; two for coagulopathy, one for surgical bleeding, and one to rule out tamponade (negative). In those patients with EMI in whom streptokinase fails to result in adequate reperfusion, immediate emergency saphenous vein bypass grafting may be performed with reasonable morbidity and with acceptable hematologic consequences.

Adult↗
PubMed1984

Inflammatory epicardial reaction to processed bovine pericardium: case report.

Processed bovine pericardium is increasingly used as a pericardial substitute. It is allegedly nonreactive with epicardium, but adequate clinical data are lacking on this subject. A case report is presented wherein a dense epicardial reaction to processed bovine pericardium was found at reoperation. Histologic examination confirmed the presence of a severe inflammatory response.

Animals↗
PubMed1983

Percutaneous initiation of cardiopulmonary bypass.

Improved technology has allowed us to develop support pumps that can be applied rapidly and safely. A system utilizing thin-walled (4 mm inner diameter) percutaneously inserted sheaths has been designed for rapid bedside arterial and central venous cannulation to establish femoral arterial and venous cardiopulmonary bypass. The system utilizes two 30-cm-long large-bore, thin-walled (end and side holes) venous cannulas and a single 15-cm-long (end hole) arterial reperfusion cannula, which is connected to a pediatric oxygenator and a vortex pump head. Five patients with refractory cardiac arrest who could not be resuscitated by conventional means were revived with this system. Application time was approximately five minutes. This system appears to be an easily applied and reliable short-term mechanical support device.

Cardiopulmonary Bypass↗
PubMed1983

Emergency coronary artery reperfusion: a choice therapy for evolving myocardial infarction. Results in 339 patients.

Between 1975 and 1982, 339 patients underwent emergency coronary artery reperfusion for treatment of evolving myocardial infarction (MI). Group I (112 patients) had reperfusion with intracoronary streptokinase. Group II (46 patients) had reperfusion with a combination of intracoronary streptokinase and percutaneous transluminal coronary angioplasty (PTCA). Group III (181 patients) had saphenous vein bypass grafting. Twenty Group I patients and one Group II patient had emergency bypass grafting as streptokinase and PTCA were unsuccessful and significant myocardium remained at risk due to residual stenosis in the MI artery. Seventy-nine percent of Group III patients had successful thrombectomy of the infarcted artery, 33% of Group I had significant residual lesions after clot lysis, and 16% of Group I and 17% of Group III patients had no observable lesion on restudy. There were 10 early and two late deaths in the surgical patients. There were two deaths in Group I and no deaths in Group II. All deaths occurred in patients who were in cardiogenic shock before reperfusion (Group IV). Late follow-up (220 patients to 78 months) revealed three late MIs, four cerebral vascular accidents, two late cardiac and three noncardiac late deaths, and 31 patients with residual symptoms. Patients with an emerging MI should be treated via reperfusion of the MI vessel by one of these techniques. With single-vessel involvement, streptokinase lysis of the intercoronary thrombosis should be attempted. If this is successful and there is a significant residual stenotic lesion, the vessel should undergo balloon angioplasty at that time. If PTCA is unsuccessful, then bypass grafting should be done. When significant multiple-vessel disease exists in conjunction with an acute MI, the patient should have emergency saphenous vein bypass grafting as the treatment of choice.

Adult↗
PubMed1983

Intravenous balloon pumping for acute right ventricular failure.

A patient with acute right ventricular failure and severe hemodynamic instability following coronary artery revascularization was treated with intra-aortic and intravenous balloon pumping. The intravenous balloon was timed to inflate during diastole and deflate during systole as did the intra-aortic balloon; in fact, the two were connected to the same system through a Y-connector. The intravenous balloon acted as an artificial atrium, which allowed approximately 20% improvement in the cardiac output when this intravenous balloon was functioning. Hemodynamic stability was achieved with this system. Intravenous balloon pumping should be considered for patients with unstable hemodynamics secondary to acute right ventricular failure.

Aged↗
PubMed1982

Surgery for evolving myocardial infarction.

One hundred fifty-six patients underwent emergency coronary revascularization during the early phases of evolving myocardial infarction (MI). There were six hospital deaths (3.8%) and two later deaths (1.3%). Thrombectomy of the MI artery was achieved in 79% of the patients, and 17% of the patients showed no observable lesion in the MI vessel on restudy. Graft patency was 99%. Late follow-up to 62 months disclosed 17 patients with residual limitations. Analysis of the data established criteria for recognizing patients with early MI who would benefit from surgical therapy. The criteria are derived by comparing preoperative and postoperative ventricular anatomy, creatine phosphokinase levels, and hemodynamics.

Clinical Enzyme Tests↗
PubMed1982

Stress analysis of porcine bioprosthetic heart valves in vivo.

During the normal functioning of aortic porcine bioprosthetic valves, the leaflets undergo complex configurational changes which can produce stresses large enough to damage the leaflets. Stress analyses of these valves in vivo have not been performed before. We investigated the behavior of aortic bioprostheses in vivo in calves by placing radiopaque markers on the valves and observing them under x-ray. Based upon the behavior of the leaflets, a method of stress analysis is proposed. Membrane stresses were associated with a pressure gradient across the leaflet and bending stresses with a change in the leaflet curvature. Total stresses were obtained by summation of the two stresses. A model of leaflet deformation at its attachment is proposed and the stresses determined. In diastole, the total stresses in the leaflet were tensile. In systole, the total stresses at the leaflet attachment were large and compressive on the aortic surface. Since the leaflet is unable to sustain compressive stresses, it is concluded that large compressive stresses cause structural damage at the leaflet attachment. This may explain the clinical observation that bioprosthetic leaflets detach or calcify in this region.

Animals↗
PubMed1982

Evaluation of the pathologic and prognostic correlates of estrogen receptors in primary breast cancer.

The presence of estrogen receptors in breast cancer tissue has been reported to correlate with improved prognosis in women after mastectomy. The prognostic value (if any) of the presence or absence of estrogen receptors (ER) in malignant breast tissue was evaluated 104 women who were treated for primary breast cancer, whose pathology was re-examined, and whose records were subjected to multifactorial analysis. Sixty patients were ER positive, and 44 were ER negative, and a total of 94 who had curative resections were available for follow-up (mean follow-up time 20 months). The presence of estrogen receptors showed significant positive correlations with age, lobular cancer, and a variant of infiltrating duct cancer that is prevalent in the elderly and characterized by the presence of cells showing granular eosinophilic cytoplasm. Of 26 cases identified as infiltrating duct cancer showing granular eosinophilic cytoplasm, 22 were ER positive, one was ER negative, and three had borderline values. There was no significant difference between the groups with regard to family history of breast cancer or hysterectomy. A striking observation was noted in the ER positive group in which there were seven cases of second primary breast cancers, whereas no such cases occurred in the ER negative patients (p=0.05). There was a higher percentage of nodal metastases in the patients who were ER positive compared with those who were ER negative; 27 of 53 (51%) of the ER positive patients has positive nodes compared with four of 40 (32%) who were ER negative, p = 0.08. There was no significant correlation of disease free survival nor time to recurrence in either the overall group nor according to stage. In patients whose tumors had been reviewed and graded, there was no prognostic relationship of ER status in high grade tumors, but in patients with low-grade tumors, improved disease-free survival was demonstrated in patients who were ER negative. Although the estrogen receptor assay is a highly useful tumor marker and guide for therapy of advanced breast cancer, its relationship to the prognostic variables of primary breast cancer is complex and controversial and merits continued study.

Age Factors↗
PubMed1982

Analysis of the design and dynamics of aortic bioprostheses in vivo.

An understanding of the in vivo design and dynamics of the present bioprosthetic valves should provide the information necessary for an improvement in their efficiency and durability. Three types of commercially available bioprostheses were prepared with radiopaque markers and implanted in the aortic position in calves. One week later, under light general anesthesia, the animals were studied to determine the in vivo design, shape, configuration, and motion of the bioprostheses. This information was then compared to that previously obtained from the natural aortic valve in vivo. The following observations were made: (1) In all three types of bioprostheses, the three leaflets opened and closed simultaneously in less than one thirtieth of a second; (2) there was no detectable flexion of the stent posts in any of the three types of valves; (3) in all of the bioprostheses studied, the greatest flexion occurred along the attachment of the leaflets; (4) the systolic and the diastolic geometry of the three types of valves was completely different for each type of valve, and none duplicated the geometry of the natural aortic valve; (5) the open configuration of the leaflets was different for each type of prosthetic valve and different from the natural aortic valve; (6) the zone of leaflet bending varied in size and extent for each of the valves. It is concluded that the differences between the design of bioprosthetic valves and that of natural valves are probably a major factor in increasing the stresses in bioprostheses. Hence stress failures could be reduced and durability increased by redesigning bioprostheses to duplicate more closely the design of the natural aortic valve.

Aortic Valve↗
PubMedDate not supplied

Estimation of pulmonary arterial pressure in the newborn: study of the repeatability of four Doppler echocardiographic techniques.

Despite the increasing use of Doppler echocardiographic (DE) techniques to determine pulmonary arterial pressure in the neonate undergoing intensive care, there have been no studies comparing their repeatability in this population. Our objective was to compare the repeatability of four such techniques in neonates. The study was conducted in two regional neonatal units serving the North East of England. Group A (repeatability between observers): Two experienced observers performed detailed DE examinations, one directly after the other. Group B (within observer repeatability/temporal variability): One observer performed two examinations 1 hour apart. Group A comprised 15 preterm babies (26-36 weeks' gestation, 975-2915 g), most with mild respiratory failure; 4 healthy term babies; and 7 with congenital heart disease, in whom tricuspid regurgitation (TR) only was measured. Their ages were 18 hours to 12 days. Group B comprised 11 babies aged 12-64 hours with moderate to severe respiratory failure; 10 were preterm (26-36 weeks, 785-2800 g). We recorded four measurements: (1) Peak velocity of TR in m/s; (2) peak left-to-right ductal flow velocity (PDAmax in m/s); (3) TPV/RVET ratio; and (4) PEP/RVET ratio, where TPV = time to peak velocity at the pulmonary valve, PEP = right ventricular preejection period, and RVET = right ventricular ejection time. The Bland-Altman analysis was used to produce the coefficient of repeatability (CR: 95% confidence limits of repeatability), also expressed as a repeatability index (CR/mean value) and as a number of "confidence steps"-a measure of sensitivity of the technique to hemodynamic change (range of values within the population/CR). Between-observer and within-observer repeatabilities were similar. Within-observer CR and index (%) results were for TR +/- 0.26 m/s (9%); for PDAmax, +/- 0.48 m/s (39%); TPV/RVET 0.1:1.0 (34%), PEP/RVET 0.12:1.00 (36%). TR and PDAmax had the largest number of confidence steps in the expected range of values (TR 8.5; PDA max 6.5; TPV/RVET 3.2; PEP/RVET 3.2). The most repeatable technique was TR, but PDAmax would also be useful for a serial study owing to the potential for large change. Systolic time interval ratios were less repeatable and likely to be less sensitive indicators of hemodynamic change.

Blood Pressure↗
PubMedDate not supplied

Hemopump support for the failing heart.

Under fluoroscopy, the hemopump is passed through the aortic valve into the left ventricle through a Gortex (WF Gore, Denver, CO) chimney sewn to a surgically exposed femoral artery. The system aspirates the left ventricular blood and actively pumps it into the aorta. Five patients (four men, one woman), aged 47-71 years (mean, 62 years), were candidates for hemopump support because of refractory cardiogenic shock. Three were recovering from repeated coronary artery bypass graft (CABG) surgery, and two required postoperative emergency CABG for failed percutaneous transluminal coronary angioplasty (PTCA). One patient died during insertion, and four had the hemo-pump successfully placed. All patients had low cardiac out-put and had intraaortic balloons in place. Average insertion time took 20 min, with maintenance on the hemopump for an average of 13 hr. One patient was maintained on the hemopump for 12 hr, but because of continued deterioration, was placed on a total artificial heart (Harvik 7-70). Patients 3 (hemopump inserted transthoracically) and 4 had the hemopump discontinued because of brain death, and the fifth survived. This patient is alive and working 1 yr later. The hemopump is an effective left ventricular support system that is less invasive than conventional transthoracic systems.

Aged↗
PubMedDate not supplied

Characteristics of drug abusers that discriminate needle-sharers.

To identify variables that discriminate needle-sharing among drug abusers, 224 male drug abusers were studied. They had been admitted to a 30-day inpatient drug treatment program over a 19-month period (September 1983 through March 1985). The variables examined were divided into three categories: demographic (age, race, education), personality (Minnesota Multiphasic Personality Inventory [MMPI] scores and MMPI deviant scores), and drug use patterns (drug of choice, use of single or multiple [mixed] drugs, severity of drug use, and place of use). Three variables were identified that discriminated needle-sharers from other drug abusers. Compared with other drug abusers, needle-sharers used more multiple drugs, were more likely to use a "shooting gallery," and had more problems related to drug use. No demographic or personality variables discriminated needle-sharers from nonsharers. The data suggested that needle-sharing is widespread in the drug culture. Needle-sharing was not confined to a particular racial group, educational level, or personality type. These findings can be used to structure education programs about acquired immunodeficiency syndrome (AIDS) for drug abusers. Drug treatment programs appear to provide an important opportunity to educate drug abusers about AIDS and related health issues associated with needle-sharing.

Adult↗