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Biomedical subjects

A Bernhard

Publications and source records attributed to A Bernhard.

At least 55 records · Page 3Linked to original sources
PubMed1988

Heterotopic heart transplantation: current indications for the procedure, with results in 10 patients.

From January 1986 to September 1987, we performed 27 orthotopic and 10 heterotopic cardiac transplantations at our institution. Of the 10 heterotopic transplantation recipients, 9 were men; ages ranged from 36 to 65 years; and indications for transplantation were ischemic cardiomyopathy in 8 patients and dilatative cardiomyopathy in 2 patients. Five of the 10 heterotopic transplantation recipients received donor hearts under emergency conditions, when no hearts of suitable size for orthotopic transplantation were available. In 3 of the 10 heterotopic procedures, we performed pure left ventricular (rather than biventricular) bypass in patients with chronic conditions requiring only aneurysmectomy, or aneurysmectomy in combination with an aortocoronary graft. During postoperative hospitalization, the following complications occurred in the 10 heterotopic-transplantation recipients: 10 infectious episodes in 6 patients; 1 episode of severe graft rejection; and 1 episode of severe gastrointestinal bleeding. All these complications were overcome, and no patient in the heterotopic-transplantation group died. Fifteen months postoperatively, one male in the group lost his graft, but his own heart had by then recovered function, despite dilatative cardiomyopathy. More commonly, late investigation (6 months or longer after transplantation) has yielded ambiguous overall evaluations of pump performance of the recipients' native hearts, showing slight improvement in some instances and further deterioration in others. We conclude that heterotopic heart transplantation is a life-saving procedure in urgent cases when only small donor hearts are available, and that it offers a good chance of hemodynamic and functional improvement not only in emergency cases, but also in cases of chronic cardiomyopathy when there is salvageable myocardium.

Journal Article↗
PubMed1987

Transplantation of aortic and pulmonary allografts, enhanced viability of endothelial cells by cryopreservation, importance of histocompatibility.

Fresh heart valve allografts were preserved at 4 degrees C for 14 days, cryopreserved and stored for 63 days, and studied for endothelial viability and antigenicity, in order to obtain some information on the immunobiological status of allografts before transplantation. The surgical technique described by Ross for subcoronary position is preferred and briefly outlined. Four explanted incompatible allografts were studied by light and scanning electron microscopy and immunohistochemistry to assess the immunological reactions and tissue changes that occurred between 9 days and 16 weeks postoperatively. Valve leaflet motion and opening velocities were studied by echocardiography postoperatively to establish a baseline with which to distinguish early leaflet degeneration. Distensibility of the aortic annulus was studied postoperatively by supraaortic angiography to justify one of the goals of reconstruction of the aortic root with allografts. Antibiotic preserved allografts at 4 degrees C showed no viable endothelial cells after 8 days while the cryopreserved allografts demonstrated a high rate of viable endothelial cells capable of expressing surface antigens (HLA class I and II). Although the valve explants showed focal mononuclear cell infiltrations with T-lymphocytes, the allografts healed in place. The "classic" findings of rejection could not therefore be demonstrated. In summary, cryopreserved valve allografts, like the fresh, are antigenic. It is therefore recommended to use compatible valve grafts, when possible, which might be a positive step to improve the functional longevity of valve allografts. Immune response after valve allograft transplantation does not cause acute valvular dysfunction but rather chronic tissue changes which might lead to early degeneration of the allograft. The opening velocities of preserved aortic and pulmonary allografts were normal at 3-4 years postoperatively irrespective of histocompatibility. Echocardiography might be a useful tool to detect early degenerative changes of incompatible valve leaflets. The aortic root is distensible after allograft transplantation.

Adolescent↗
PubMed1986

Cardiac rhythm and conduction after two-stage anatomic correction of simple transposition of the great arteries.

To assess postoperative arrhythmias and AV-conduction defects associated with anatomic correction of simple transposition of the great arteries, 207 standard 12-lead surface and 43 24-hour electrocardiograms of all 17 patients followed after anatomic correction for up to 6.5 years were reviewed. No dysrhythmias or AV-conduction delays definitely attributable to anatomic correction were observed. One patient with a severe complex supraventricular tachyarrhythmia after a Blalock-Hanlon procedure has improved markedly, exhibiting respiratory AV-dissociation and 5 premature atrial complexes/minute 5 years after anatomic correction.

Arrhythmias, Cardiac↗
PubMed1986

Up to 7 years of follow-up after two-stage anatomic correction of simple transposition of the great arteries.

In 16 patients, constituting 100% of children followed for up to 7 years after two-stage anatomic correction of complete transposition of the great arteries, clinical and electrocardiographic data, as well as cardiac catheterization data in 12 patients, were analyzed. None of them has had signs or symptoms of coronary or myocardial insufficiency after an adaptation phase of 6 months after anatomic correction. Body weight normalized 3 to 6 months after anatomic correction, and was normal in most cases after 1 year. No atrioventricular conduction delays or arrhythmias definitely attributable to anatomic correction were observed. Peak systolic pressure in the right ventricle was slightly elevated in 10 of 12 patients studied due to residual pulmonary stenosis from the band site. End-diastolic and end-systolic volumes as well as ejection fraction and end-diastolic pressure of the right ventricle were normal. End-diastolic and end-systolic volumes of the left ventricle were elevated (p less than .01), while muscle volume, ejection fraction, and end-diastolic pressure were normal. The pulmonary root was distended during the banding stage and did not dilate as did the aortic root after anatomic correction. Patients with complete transposition of the great arteries up to 7 years after anatomic correction develop normally without atrioventricular conduction delays, arrhythmias, or signs of coronary and myocardial insufficiency. The enlarged aortic root does not seem to dilate. The reasons for elevated left ventricular volumes are not clear at the present time. Earlier operation may prevent these changes.

Body Weight↗
PubMed1985

Influence of the two-stage anatomic correction of simple transposition of the great arteries on left ventricular function.

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great arteries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = 11), and compared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 +/- 10) and between 13 and 47 months (mean 24 +/- 10), respectively. The interval between anatomic correction and the investigation ranged from 10 to 29 months (mean 20 +/- 7). After banding, LV ejection fraction decreased (p less than 0.01) and LV peak systolic pressure (p less than 0.01) as well as LV end-diastolic pressure (p less than 0.05) increased. After anatomic correction, these variables and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 patients after anatomic correction was within control range. The highest values were found in the youngest patients at banding and at anatomic correction. In contrast to measures of global myocardial function, such as LV ejection fraction and LV end-diastolic pressure data, the LV end-systolic stress-ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.

Age Factors↗
PubMed1985

Internal mammary artery as a palliative systemic-pulmonary shunt in order to develop diminutive pulmonary arteries.

Diminutive pulmonary arteries remain a problem in the surgery of congenital heart disease. This is the second report of a case in which the internal mammary artery was successfully used to enlarge small pulmonary arteries by 50% within 9 months accompanied by improvement of the symptomatic state in a patient with pulmonary atresia and diminutive left pulmonary arteries.

Adolescent↗
PubMed1985

Implantation of a xenogeneic stentless aortic bioprosthesis. First experience.

To overcome the specific disadvantages of mechanical valves and stented bioprostheses, we implanted a stentless xenogeneic aortic valve in a patient with calcified aortic stenosis. The postoperative study revealed a pressure gradient of 25 mmHg, a minor insufficiency of 10% of total stroke volume and a slightly restricted motion of the leaflets. Although the implantation of a stentless xenogeneic aortic valve is feasible, one should be aware of the specific technical difficulties due to the increased rigidity of the fixed tissue, which is not known in homografts. To our knowledge this is the first report on the implantation of a stentless xenogeneic aortic valve.

Aortic Valve↗
PubMed1985

Allogeneous transplantation of the mitral valve. An open question.

To overcome the disadvantages of mechanical valves and bioprostheses, especially in the mitral position, transplantation of an allogeneous mitral valve was performed in 3 patients. One transplant had to be removed 8 weeks postoperatively, most probably due to maladjustment of the anterior leaflet during surgery. The histology of this specimen showed not clear signs of rejection. In 2 patients, echocardiography showed a normal motion pattern of the mitral valves 6 months postoperatively. Regurgitation was less than 10% of the total stroke volume as calculated by videodensitometry. Both patients were in excellent clinical condition. Mitral valve transplantation can be performed with excellent short-term results. Further studies including immunologic monitoring are necessary to evaluate the long-term behavior of the transplant.

Adult↗
PubMed1985

Replacement of the aortic root by free implantation of a stentless aortic porcine bioprosthesis in a patient with aneurysm of the sinuses of Valsalva.

In a patient with aneurysms of the sinuses of Valsalva a stentless porcine bioprosthesis was implanted with excellent hemodynamic and clinical short-term results. The implantation technique was similar to the technique used for the implantation of a composite graft. The postoperative study revealed a pressure gradient of 7 mmHg between the left ventricle and aorta and no regurgitation. Although the implantation of a porcine aortic root including a part of the ascending aorta without any artificial stenting material is feasible, one should be aware of the specific technical difficulties due to the increased rigidity of the fixated tissue. To our knowledge this is the first report of an implantation of a stentless aortic root porcine bioprosthesis for the treatment of aneurysms of the sinuses of Valsalva.

Animals↗
PubMed1985

Surgical implications of early branching of the left coronary artery in anatomic correction of transposition of the great arteries.

Early branching of the left coronary artery (LCA) may become an additional operative challenge during coronary transfer in anatomic correction of transposition of the great arteries. An early branch of the LCA running in opposite transfer direction was present in 3 out of 25 patients who underwent anatomic correction. By excising a large cuff of aortic sinus wall around the ostium of the LCA enough length was gained for successful coronary transfer without kinking in 2 patients in whom the first branch was arising at the level of the origin of the circumflex artery. In the third patient with the first branch arising proximal to the origin of the circumflex artery an alternative surgical procedure seemed preferable. In such a coronary anomaly optimal visualization of the coronary branching pattern, possibly including selective coronary angiography, is advisable for better planning of the surgical technique.

Coronary Vessel Anomalies↗
PubMed1985

Assessment of coronary and aortic anastomoses after anatomic correction of transposition of the great arteries.

Anatomic correction of transposition of the great arteries always entails circumferential anastomoses of the aorta and coronary arteries. Long-term success of this procedure is predicted on adequate growth of these anastomotic sites. To assess the size of these arteries, we performed one or two cardiac catheterization on 25 children from 1 to 53 months (mean 18.8 months) following anatomic correction. Early studies (mean 12 months) were performed in 23 patients and late studies (mean 30 months) in 13 patients. Age at repair ranged from 2 to 168 months (mean 25.5 months) and 15 patients were less than a year of age. Fifteen patients had undergone previous pulmonary artery banding in preparation for anatomic repair. Postoperative catheterizations showed no area of narrowing at the aortic or coronary anastomoses and no kinking of the proximal coronary arteries. Almost all normalized diameters of the aortic root were larger than normal. There were no differences between early and late measurements after anatomic correction. No patient had a pressure gradient across the aortic anastomosis. It is, therefore, concluded that the coronary and aortic anastomoses allow for satisfactory growth even when there has been previous pulmonary artery banding.

Aorta, Thoracic↗