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Biomedical subjects

H H Scheld

Publications and source records attributed to H H Scheld.

At least 307 records · Page 17Linked to original sources
PubMed1987

PTFE grafts to the right coronary artery following endarterectomy.

In ten of 3031 patients undergoing coronary surgery, we used a PTFE graft for bypass to the right coronary artery following endarterectomy. Diffuse calcification was the reason for endarterectomy of the right coronary artery in all cases. We chose a PTFE graft only in those cases where autologous grafts were not available in a sufficient number. After a mean follow-up period of twelve months nine of the ten grafts were patent.--This study demonstrates that under selected circumstances PTFE grafts can be successfully used in coronary surgery if autologous grafts are lacking.

Blood Vessel Prosthesis↗
PubMed1986

Myocardial protection of hypertrophied hearts by administration of cardioplegia according to regional myocardial temperature.

Hypertrophied hearts are known to be extremely vulnerable to ischemia. During cardioplegic arrest different regional myocardial temperature are known to occur. We investigated myocardial protection in 61 patients with aortic valve disease undergoing aortic valve replacement. Three different cardioplegic solutions were used. Regional myocardial temperature was continuously controlled and adjusted to a temperature of not more than 15 degrees C by intermittend infusion of cardioplegia. Before, after heart arrest and after 10 minutes of reperfusion we did myocardial biopsies and determined high energy phosphates and lactate. From our results we conclude that three cardioplegic solutions were able to protect hypertrophied hearts adequate during an ischemic period of 60 minutes if the regional myocardial temperature does not increase above 15 degrees C.

Body Temperature↗
PubMed1986

Ultrastructure of the human myocardium after intermittent ischemia compared to cardioplegia.

A lot of reports informed about the detrimental effects of intermittent ischemia nevertheless this method is still used during coronary surgery. We investigated the myocardial protection due to cardioplegic arrest compared to intermittent ischemia in 120 patients undergoing coronary surgery. In all patients we took myocardial biopsies from the left ventricle before and after ischemia. Electron microscopic studies of all biopsies were performed and the degree of ultrastructural alteration was determined. The ischemic period in the cardioplegic group was 61 +/- 15 minutes and in the group with intermittent ischemia the total ischemic time was 45 +/- 21 minutes. After ischemia the myocardium showed most time only damage of moderate or light degree, while after intermittent ischemia the most biopsies showed severe ultrastructural damage. From our results we conclude, that intermittent ischemia is unable to protect the myocardium in a sufficient amount and should therefore no longer be used as a method of myocardial protection.

Biopsy↗
PubMed1986

The influence of extracorporeal circulation on extravascular lung water in coronary surgery patients.

The influence of extracorporeal circulation (ECC) on extravascular lung water (EVLW) was investigated in a total of 45 consenting patients undergoing coronary artery bypass surgery. The patients were subdivided into 3 groups according to positive fluid balance during ECC: 1. less than 500 ml; 2. 500 to 1500 ml; 3. 1500 to 3000 ml. Lung water measurement was performed intraoperatively using the thermal green-dye double indicator dilution technique, with indocyanine green and a microprocessed lung water computer, before and after ECC. In the group with high positive fluid balance during ECC (group 3) EVLW - increase was more pronounced (5.18 ml/kg----8.18 ml/kg) than in the groups with lower positive fluid input (group 1: 5.35 ml/kg----5.68 ml/kg, group 2: 5.56 ml/kg----6.70 ml/kg). Extravascular lung water increase was accompanied by a deterioration of pulmonary gas exchange demonstrated by the greatest decrease of paO2 in group 3 (490 mmHg----243 mmHg). No significant relationship of lung water changes to various hemodynamic parameters was observed in this study.

Body Water↗
PubMed1986

Closure of longitudinal sternotomy with absorbable sutures.

In a consecutive series of 150 patients who underwent open heart surgery, absorbable suture (PDS-Ethicon) were used for the closure of median sternotomy. One patient developed sternal dehiscence; wound complications or incompatibility with the suture material did not occur. With the technique of "double" PDS sutures, rapid and secure sternal closure can be performed even in cases of friability of the sternum without cutting through the sternal bone.

Cardiac Surgical Procedures↗
PubMed1986

Ultrastructural study comparing the efficacy of five different methods of intraoperative myocardial protection in the human heart.

The quality of myocardial protection during cardiac arrest in cardiac operations was investigated in 310 patients. Eighty patients underwent aortic valve replacement and 230 had coronary artery bypass grafting. Four different cardioplegic solutions (Kirsch, Bretschneider, St. Thomas' Hospital, and Hamburg) and the method of induced fibrillation were tested by ultrastructural analysis of the degree of ischemic injury at the end of the cardiac arrest period. Hypothermia was identical in all five groups. In this study, subendocardial and subepicardial needle biopsies were evaluated by a standardized scoring system. Chemical cardioplegia produced mainly moderate ultrastructural injury independent of the time of ischemia. Kirsch cardioplegia and the intermittent fibrillation procedure produced ischemic injury of greater and unpredictable severity. Only with Kirsch cardioplegia was a correlation observed between the duration of intraoperative arrest and the degree of injury, which is indicative of a lack of myocardial protection. The tolerance to ischemia was significantly better in patients undergoing bypass grafting than in those with aortic valve disease and therefore longstanding hypertrophy. In conclusion, the Bretschneider, St. Thomas' Hospital, and Hamburg solutions provide satisfactory myocardial protection but are not able to completely prevent myocardial ischemic injury. Kirsch cardioplegia and the intermittent fibrillation procedure provide insufficient myocardial protection. Patients with left ventricular hypertrophy are at a greater risk during cardiac operations than patients undergoing coronary bypass operations.

Aortic Valve↗
PubMed1986

[Separation of a Beall Surgitool prosthesis disk 15 years after mitral valve replacement].

The case of a 46-year-old woman who survived disc embolization of a Beall Surgitool prothesis for 10 days is described. The patient presented to another hospital 15 years after implantation of a mitral valve prothesis with acute severe heart failure refractory to medical therapy. Ten days later she was referred for cardiological investigation and a missing mitral valve disc was diagnosed by echocardiography and right heart catheterization. Immediate surgical valve replacement led to a good recovery. The embolized disc was later localized by ultrasound and abdominal CT and removed from the abdominal aorta.

Aorta, Abdominal↗
PubMed1986

Incidence and pathogenesis of late aneurysms after patch graft aortoplasty for coarctation.

From 1957 to 1984 direct and indirect isthmoplasty as described by Vossschulte has been the method of choice for surgical therapy of coarctation of the aorta in our hospital. A total of 317 patients have been so treated, 54 of whom were less than 12 months old at operation. The hospital mortality in this group was 15% and the mortality in patients older than 1 year was 3%. The early results were encouraging, but during follow-up an increasing number of postoperative aneurysms have been detected. During reinvestigation an aneurysm was diagnosed in 18 cases. Therefore, we have studied the cause of these aneurysms. To this point reoperation has been performed in 15 patients having late aneurysms. Extensive resection of a fibrous membrane of the aortic isthmus at the first intervention seems to be an essential predisposing factor for development of aneurysms. Microscopic examination of the aneurysmal wall revealed degeneration of the media in more than half of the patients. From our experience we conclude that the posterior fibrous ridge should no longer be excised and the Vossschulte operative technique should be viewed more critically.

Adolescent↗
PubMed1985

Combined therapy of re-coarctation of the aorta and coronary heart disease.

We report on an uncommon case of recoarctation of the aorta 36 years after resection and end-to-end anastomosis associated with coronary heart disease. Since a two-staged surgical therapy implies an increased risk of life for the patient, we decided to perform a combined surgical procedure. Exposing the heart by a median sternotomy we implanted a 16 mm synthetic graft from the ascending to the descending thoracic aorta and performed a prosthesio-coronary bypass in one session. The patient had an uneventful recovery. In our opinion this procedure is the method of choice for similar cases.

Adult↗
PubMed1985

Protection of the hypertrophied human heart by adjusting regional myocardial temperature to a safe level.

Uneven distribution of temperature and the persistence of electro-mechanical activity after aortic cross-clamping are 2 factors limiting the myocardial protection during cardioplegic arrest, especially in hypertrophied hearts which are known to be extremely vulnerable to ischemia. In the present study regional myocardial temperature (T) was continuously controlled, and the time until arrest occurred (delta t) was determined in 61 patients undergoing aortic valve replacement. In addition, the myocardial contents of high energy phosphates and lactate were assessed. Three different cardioplegic solutions were employed: In the first group we used Bretschneider solution (Br), in the second group St. Thomas' solution (St), and in the third group the so-called "Hamburg cardioplegia" (H). During cardiac arrest the regional myocardial temperature was adjusted to temperatures not exceeding 15 degrees C by intermittent infusions of cold cardioplegic solution. We found a positive correlation between left ventricular muscle mass (LVMM) and delta t. A negative correlation existed between LVMM and adenosine triphosphate (ATP) contents at the end of the ischemic period. The cooling characteristics and delta t were significantly longer and the cooling to 15 degrees C was less rapid when H was used. Adenosine-triphosphate contents were well preserved during ischemia in all 3 groups. We conclude that all 3 cardioplegic solutions tested protect the hypertrophied myocardium adequately if the regional myocardial temperature does not increase above 15 degrees C during cardiac arrest. Hearts with a higher LVMM showed a decreased myocardial ATP content at the end of the ischemic period. Therefore, the LVMM may limit myocardial protection.

Adenosine Triphosphate↗
PubMed1985

[Significance of endocrine parameters of stress].

Thirty two male patients undergoing coronary bypass surgery were given low (group A, 0.01 mg/kg bw) and high dose (group B, 0.035 mg/kg bw) fentanyl anaesthesia. Haemodynamic and hormone responses were investigated from the beginning of anaesthesia until extracorporeal circulation (ECC) (group A: n = 16; group B: n = 16). Significant changes in haemodynamics occurred only in group A including an increase in heart rate (36%) and systolic arterial pressure (21%). Plasma vasopressin (ADH) levels rose significantly in both groups after the beginning or surgical procedure which was markedly less pronounced in patients with high fentanyl (group B). In group A (low dose) a second dose of fentanyl was given after sternotomy, which was followed by a significant decrease in ADH (80% from previous value). No significant variations could be demonstrated in plasma levels of cortisol, ACTH, and human growth hormone (HGH). The data stress the importance of plasma-vasopressin-levels in determining the endocrine stress response following trauma and operation. On the other hand there was a lack of correlation between trauma and pain and frequently reported patterns of the endocrine-metabolic stress response.

Adrenocorticotropic Hormone↗
PubMed1985

[Thrombosis of a St. Jude Medical valve in malignant lymphoma and extensive blood vessel malformation].

We present a case of thrombosis of a St. Jude Medical valve in mitral position at the time of manifestation of an acute malignant lymphoma. Since valve thrombosis and the onset of acute malignant lymphoma appeared simultaneously, we conclude that the malignant lymphoma may have been the cause of valve thrombosis. In our case report we discuss the genesis and prophylaxis of valve thrombosis during malignant disease.

Heart Valve Prosthesis↗
PubMed1984

Sarcoma of the lung in a pacemaker pocket--simple coincidence or oncotaxis?

An 82-year-old man developed a soft-tissue sarcoma in the subpectoral pocket of a titanium-covered pulse generator that had been replaced 8 months previously without evidence of tumor. The tumor represented a metastatic manifestation of a malignant fibrous histiocytoma situated in the contralateral lower pulmonary lobe. The patient died some weeks postoperatively due to cachexia. Autopsy revealed no further metastases. The appearance of cancer in patients with pacemakers is probably coincidental and not related to material or electrochemical stimulation, although the site of the generator pocket might be oncotactic because of the irritation that would trap tumor cells and provide disruption in the intracellular endothelial barrier allowing migration of the tumor cells into tissues. Possible causes and relationships are reviewed.

Aged↗