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Biomedical subjects

W F Bernhard

Publications and source records attributed to W F Bernhard.

16 recordsLinked to original sources
PubMed1979

Temporary left ventricular bypass: factors affecting patient survival.

Circulatory support (range, 2 hours-8 days) was undertaken in eight cardiac surgical patients (with two survivors) exhibiting intractable cardiogenic shock. A paracorporeal, pneumatic, xenograft-valve pump was interposed between the left ventricular apex and ascending aorta. Pumping lowered left atrial and ventricular pressure while maintaining cardiac output (1.8--2.6 l/min/m2). Following implantation, plasma hemoglobin and erythrocyte mechanical fragility values were elevated but decreased to normal when renal function was not impaired. Mild thrombocytopenia was noted in three patients and was severe in five others with persistent hemorrhage. Anticoagulation agents were used during tapering of pump flow (three patients) after 100, 105 and 120 hours of bypass. Otherwise, for the major portion of the interval of mechanical circulatory support, anticoagulants were not administered. Despite this fact, no systemic embolization was detected in any of the patients. It appears that assist pump support can be life-saving in acute left ventricular failure in patients following cardiac surgery.

Adult↗
PubMed1979

Successful use of a left ventricular assist device in cardiogenic shock from massive postoperative myocardial infarction.

A 41-year-old man underwent an uneventful aorta-coronary bypass for unstable angina pectoris. Four hours later, a massive anterior wall myocardial infarction resulted in cardiac arrest. Conventional resuscitative means were not effective. A left ventricular assist device (LVAD) was successfully employed for 94 hours. The patient is alive and well 8 months postoperatively.

Adult↗
PubMed1978

An appraisal of blood trauma and blood-prosthetic interface during left ventricular bypass in the calf and humans.

Mechanical circulatory support was accomplished in 20 calves (mean, 140 days) and in 5 patients following operation for acquired heart disease (range, 1 hour to 8 days) employing a pneumatically actuated xenograft-valved assist pump interposed between the left ventricular apex and aorta. Following pump implantation in calves, hematocrit and platelets decreased transiently and returned to normal within 14 days. Plasma hemoglobin and erythrocyte mechanical fragility values were elevated for 48 hours. Platelet survival was slightly reduced, but erythrocyte survival values were similar to controls. In patients who received assist pumps, plasma hemoglobin and erythrocyte mechanical fragility were transiently elevated, but rapidly decreased to normal. Thrombocytopenia occurred only in the presence of bleeding and renal failure requiring hemodialysis. Pump flow of the left ventricular assist device was maintained above 2.0 L/min/m2 despite serious arrhythmias. Postmortem examination revealed no evidence of thromboemboli in the clinical patients although anticoagulant agents were not administered.

Adult↗
PubMed1978

Mechanical circulatory support in postoperative cardiogenic shock.

A 38-year-old white woman had cardiogenic shock after elective mitral valve replacement and was unresponsive to pressor drugs and intra-aortic balloon counterpulsation. A left ventricular assist device (left ventricle to ascending aorta) was implanted 16 hours after the initial operation and provided circulatory support for 8 days. Improvement in the patient's own cardiac performance was documented, and there were no complications attributable to the assist device. However, intercurrent medical problems resulted in clinical deterioration on the fifth day after operation, and the patient died 8 days after operation. The findings in this patient suggest a potential role for this left ventricular assist device in future cases of acute, intractable, but potentially reversible myocardial failure.

Acute Kidney Injury↗
PubMed1977

Ascending aorta-pulmonary artery anastomosis for cyanotic congenital heart disease.

The course and prognosis of 208 patients with an ascending aorta to pulmonary artery anastomosis is reviewed. Mortality rate during, or within one month, of surgery was 24 per cent (50/208) and late mortality rate, prior to repair, was 10 per cent (21/208). An additional 5 per cent (10/208) died during subsequent intracardiac repair. Congestive heart failure developed in 25 per cent (53/208), pulmonary artery hypertension in 17 per cent (12/72), and pulmonary vascular obstruction in 6 per cent (4/72). An increase in orifice size of the stoma with time was documented in eight patients. Additional subsequent palliative surgery was required in 22 per cent (45/208). Mortality rate was directly related to age at operation and was highest in neonates less than one week of age. In infants with tetralogy of Fallot, a preliminary comparison of mortality rate between palliative surgery and primary repair clearly suggests that the latter is the preferred method of treatment.

Aorta↗
PubMed1977

Experience with valved conduits for repair of congenital cardiac lesions.

Dacron valved conduits or aortic allografts were placed between the right heart and the pulmonary artery for repair of various complex congenital cardiac anomalies in 56 patients (aged 15 days to 33 years; median, 11 years). Forty-four patients had a total of 56 previous palliative procedures, which contributed to postoperative morbidity and mortality. Six patients had a total of seven episodes of early or late sepsis involving the conduit. One patient, treated for early sepsis, again developed infection in the Hancock graft 1 year postoperatively and died. Three other patients, 2 with calcified allografts, developed infections 4 months to 7 years following repair and required graft replacement. Hemodynamic data 1 month to 5 years (mean, 1.6 years) following repair revealed mild to moderate obstruction (less than 45 mm Hg gradient) at the Hancock conduit valve ring in 13 of 19 patients, while 5 had large pressure gradients (greater than 75 mm Hg). All aortic allografts had severe obstruction and calcification necessitating graft replacement. It is anticipated that improved technique and appropriate timing of palliative and corrective operations will substantially reduce or eliminate these problems.

Adolescent↗
PubMed1977

Repair of tetralogy of Fallot after aortopulmonary anastomosis.

Thirty-eight corrective operations have been performed in patients with tetralogy of Fallot and a functioning aortopulmonary shunt. There were 3 operative deaths (7.9%) and 1 late death (2.6%), and 3 patients have required reoperation for significant residual defects. Only 1 of 10 patients studied postoperatively by radionuclide scanning has a significant reduction in blood flow to the lung on the side of the closed shunt. We conclude that the presence of an aortopulmonary shunt does not add to the risk of repair in patients with tetralogy of Fallot and that mortality after such operations is related to the complex anatomy often present in patients of this group.

Adolescent↗
PubMed1977

Tetralogy of Fallot with a single pulmonary artery: operative repair.

Surgical repair was performed on 8 patients with tetralogy of Fallot and congenital or acquired absence of the left pulmonary artery. Prior palliative systemic-pulmonary artery shunts had been performed in the 5 patients with acquired absence of the pulmonary artery, and in none was repair of the damaged pulmonary artery possible. A valve-containing conduit (Hancock) was used in each patient to prevent pulmonary valvular regurgitation during the early postoperative period. All patients survived operation and have exhibited marked symptomatic and hemodynamic improvement. This contrasts with the poor results of corrective operation previously reported in patients in this diagnostic category. We believe that the present improved results are due in large part to the valved conduit, and we therefore recommend its use during repair in children or adults with tetralogy and a single pulmonary artery.

Cardiac Catheterization↗
PubMed1977

Congenital mitral stenosis. A review of 20 years' experience.

The clinical course of 38 patients with congenital mitral stenosis (MS) is reviewed. Associated cardiac defects were present in 28 patients, including tetralogy of Fallot in five. In all but one of the eight patients with supravalvar mitral ring (SVR), there were concomitant abnormalities of the mitral valve. Delay in the diagnosis of MS was common. Serial cardiac catheterizations and pulmonary pathologic examination indicated that pulmonary vascular obstructive disease develops during childhood. Mitral valve surgery was performed in 19 of 38 patients: valvotomy alone in eight, excision of SVR in five (two ofwhom also had valvotomy) and mitral valve replacemtnt in seven. Additional non-mitral cardiac surgery was performed in 18 patients. Overall surgical mortality was 49%; mortality for surgery on the mitral valve was 26%. Only patients having mitral valve replacement or with isolated SVR which was then resected became asymptomatic and had normal hemodynamics on postoperative catheterization.

Adolescent↗
PubMed1976

The surgical management of discrete and diffuse supravalvar aortic stenosis.

Between 1956 and 1976, 18 patients underwent surgery for supravar aortic stenosis at the The Children's Hospital Medical Center, Boston. Discrete obstruction, present in 11, was treated by insertion of a prosthetic gusset placed across the area of narrowing and extending into the noncoronary sinus of Valsalva. There was one operative death. Residual gradients (measured in five patients) ranged from 4-55 mm Hg, one of which was supravalvar in location. Significant aortic regurgitation was not common preoperatively. The diffuse form of supravalvar obstruction, a more difficult surgical problem, was present in seven patients. There were three operative deaths. Complete relief of the pressure gradient was achieved only in one instance by insertion of a left ventricular-aortic bypass shunt diverting the majority of the cardiac output into the descending thoracic aorta. This patient is now asymptomatic 20 months following operation. On the basis of this experience, it is suggested that patients with the diffuse form of supravalvar obstruction, and perhaps even those with a hypoplastic annulus alone, would benefit from a left ventricular-aortic bypass shunt.

Adolescent↗
PubMed1976

The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. A report of eight patients.

Five patients with double outlet right ventricle, ventricular septal defect, pulmonary arterial hypertension and pulmonary vascular obstructive disease and three patients with complete d-transposition of the great arteries, ventricular septal defect, pulonary arterial hypertension and pulmonary vascular obstructive disease underwent an elective Mustard baffle operation. The ventricular septal defect was not closed. A large patent ductus arteriosus was divided in three patients. Seven of the eight patients are alive five to 32 months after surgery; one patient died 11 months after surgery. Cyanosis, dyspnea on exertion, and exercise limitation improved initially in all and has persisted in the survivors. In pre and postoperative hemodynamic studies in four patients, systemic arterial oxygen saturation and effective pulmonary blood flow increased from mean values of 70% to 90% and 1.7/min/m2 to 3.3 L/mon/m2, respectively. Absolute systemic and pulmonary flows, and pressures and resistances, were not significantly altered. Criteria for selection of patients with transposition of the great arteries of double outlet right ventricle who would benefit from a palliative Mustard procedure (Mustard atrial baffle without closure of the ventricular spetal defect) are: 1) severe symptoms; 2) pulmonary arteiral hypertension (75% systemic) with pulmonary vascular obstructive disease; and 3) pulmonary artieral oxygen saturation greater than systemic (ascending aorta) arterial oxygen saturation by approximately 10%.

Adolescent↗
PubMed1975

Results of routine preoperative coronary angiography in tetralogy of Fallot.

In the surgical repair of tetralogy of Fallot, morvidity and mortality are increased by certain coronary anomalies, in particular, an anterior descending branch originating from the right coronary artery or a single coronary artery in which a large coronary branch runs across the pulmonary outflow tract. In series of 94 patients with tetralogy of Fallot who underwent cardiac catheterization, coronary artery visualization was attempted routinely, most often by flush aortography using a venous catheter. Diagnostic coronary visualization was obtained in 84 patients (89%). In these, the incidence of recognized coronary anomalies was 5%; anterior decending from the right coronary artery in four patients (4%), and singly left coronary in one patient (1%). In 195 autopsied cases of tetralogy, the incidence of coronary anomalies was also 5%. Routine preoperative demonstration of the coronary artery anatomy in tetralogy patients usually can be accomplished satisfactorily and conveniently by transvenous flush aortography.

Adolescent↗
PubMed1975

Aortic stenosis surgery in infancy.

During the past 14 years, 28 infants (23 males) underwent valvotomy for severe aortic stenosis at the Children's Hospital Medical Center in Boston. The median age was two months and the oldest patient was six months old. Congestive heart failure was present in all but two babies. Preoperatively, the electrocardiogram was abnormal in all, with left ventricular hypertrophy and a strain pattern being present in 19. At cardiac catheterization, the peak systolic ejection gradient (PSEG) ranged from 35-130 mm Hg (median 90 mm Hg). Associated cardiac lesions were present in 39%. Twenty-four infants underwent valvotomy with inflow occlusion. Four patients were operated upon using cardiopulmonary bypass. There were eight early and two late deaths. The 18 survivors have been followed from six months to 11 years (median five years). Only four are symptomatic. Mild aortic regurgitation developed postoperatively in six patients, moderate in one and severe enough to require valve replacement in another one. The electrocardiogram improved postoperatively in 15 patients, but became entirely normal only in one. Five children required a repeat valvotomy for residual stenosis 1-10 years after the original procedure (median four years). At this second operation, the majority of the valves were flexible and noncalcified, and valvotomy was accomplished without difficulty. One child who underwent valve replacement for aortic regurgitation at age two years is well seven years later.

Angiocardiography↗
PubMed1975

Relief of congenital obstruction to left ventricular outflow with a ventricular-arotic prosthesis.

Hypoplasia of the aortic valve annulus and ascending aorta is a rare form of congenital aortic stenosis, with a poor prognosis. Replacement of the aortic valve and ascending aorta with a suitable prosthesis is feasible, but the hypoplastic valve annulus must also be enlarged if an adult-sized aortic valve is to be placed in the subcornary position. In an effort to develop a new method of surgical treatment for this congenital abnormality, we fabricated a prosthesis which can be interposed between the left ventricular apex and descending thoracic aorta. This prosthesis is coupled to a 25 mm. Dacron graft and xenograft valve and is lined with flocked Dacron fibrils to encourage formation of a stable biologic lining and prevent thrombus buildup. The prosthesis was implanted in a 22 year old male patient of the Children's Hospital Medical Center without difficulty. Postoperative cardiac catheterization idicated that all of the contrast material was ejected from the left ventricle through the prosthesis. The patient was discharged from the hospital taking sodium warfarin and remains entirely asymptomatic.

Adult↗
PubMed1975

A new method for temporary left ventricular bypass. Preclinical appraisal.

Surgical patients who cannot be weaned from cardiopulmonary bypass during operation or who develop balloon-dependent left ventricular failure postoperatively are now considered unsavable. However, in those with potentially reversible ventricular dysfunction, recovery might be possible if an improved means of temporary circulatory support were available. Towards this end, a pneumatically actuated, left ventricular assist pump was developed and evaluated in 20 consecutive calf experiments. The device, containing a flexible polyurethane pumping chamber, was positioned on the chest wall and connected to the left ventricular apex and descending thoracic aorta by two Dacron valved conduits (xenograft valves). All animals survived a 14 to 30 day pumping interval, and 7 underwent successful removal of the device by division of the Dacron conduits below skin level. As a prelude to human investigation, pumps were implanted during a series of routine autopsies through midline sternotomy incison. The device was positioned on the right anterolateral chest wall, with two valved conduits traversing the mediastinum to connect the pump to the left ventricular apex and ascending aorta.

Animals↗