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Biomedical subjects

H G Borst

Publications and source records attributed to H G Borst.

At least 145 records · Page 8Linked to original sources
PubMed1987

[Ectopic atrial tachycardia: surgical therapy (case report and review of the literature)].

Focal atrial tachycardia with frequencies up to 200/min in an 11-year-old girl had been resistant to drugs over a period of 5 years. An electrophysiological study demonstrated a left atrial ectopic tachycardia. Intraoperative epicardial mapping localized the automatic focus at the base of the left atrial appendage. Excision of the appendage and cryoablation of the adjacent area were performed using cardiopulmonary bypass. Histological examination of the excised tissue showed no specific alterations aside from islets of fatty tissue. The girl has been in sinus rhythm and has shown no tachycardias during the 6 months following the operation. Review of the literature covering 17 cases of right and 12 cases of left atrial focal tachycardia indicates excision of the atrial tissue in combination with cryoablation to be the treatment of choice to ensure success.

Child↗
PubMed1986

Complete correction of total anomalous pulmonary venous drainage: experience with 53 patients.

From January, 1973, to August, 1984, 53 infants with total anomalous pulmonary venous drainage (TAPVD) underwent a corrective operation in our unit. TAPVD was of the supracardiac type in 41% of the patients, cardiac in 17%, infracardiac in 36%, and mixed in 6%. Overall operative mortality was 23%; it was highest at 42% in the infracardiac group. Factors determining the outcome were the anatomical type of the lesion, the degree of pulmonary venous obstruction, the severity of pulmonary hypertension, and the young age of the patients. In addition, surgical experience appears to be an important factor in determining the outcome. During the study, hospital mortality decreased considerably to 11%. A corrective procedure offers the only chance of survival for patients with TAPVD. With some experience, excellent results can be obtained.

Age Factors↗
PubMed1986

Experimental and clinical experiences with double-velour woven Dacron prostheses.

Double-velour woven Dacron prostheses were investigated both experimentally and clinically. In 6 mongrel dogs, a tandem conduit between the right ventricle and the pulmonary artery was implanted, consisting of a plain woven and a double-velour woven graft. Following explanation after 2, 4, and 6 months, superior healing properties of the double-velour woven prostheses could be assessed by microscopy, as represented by an increase of tissue ingrowth, as well as by a thin and densely adherent inner healing capsule. Double-velour woven grafts were implanted in 50 patients undergoing open heart surgery. All grafts were presealed with fibrin glue and no bleeding could be detected at the time of implantation, even under the adverse influence of full heparinization and extracorporeal circulation.

Animals↗
PubMed1986

Clinical experience with a new collagen-coated Dacron double-velour prosthesis.

Vascular grafts with primary zero porosity are desirable in surgery for aortic aneurysms with intraoperative partial or total systemic heparinization of the patient. The present study describes the clinical application and results of a new knitted Dacron double-velour prosthesis (primary porosity: 1,400 cc/min/cm2), coated with cross-linked bovine collagen; the resulting porosity for implantation is O cc/min/cm2. Such grafts were implanted in 111 patients between 12/83 and 11/84: for replacement of the infrarenal aorta in 74 aneurysms, for replacement of the thoraco-abdominal aorta in 4 instances, and for replacement of 13 aneurysms of the descending aorta. In 20 patients with arterial occlusive disease, the prosthesis was employed as bifurcation graft. In 43 cases (38%) the underlying disease was a ruptured (26) or symptomatic aortic aneurysm requiring emergency operation. There was no leakage from any of the implanted grafts regardless of whether partial (100 units/kg BW) or total (300 units/kg BW) systemic heparinization was administered. The overall mortality rate was 11.7% (13/111). For cases of ruptured abdominal aortic aneurysm the mortality rate was 22.7% (5/22). There was no graft-related complication either in the early postoperative course or during the follow-up period (1 to 10 months, mean: 6.2 months). It is concluded that this new type of graft combines the advantages of knitted Dacron prostheses in respect to healing and incorporation with primary zero porosity, and is therefore the graft of choice in surgery for ruptured aortic aneurysm.

Adult↗
PubMed1986

Management of immediate graft failure after cardiac transplantation using cardiopulmonary bypass and intraaortic balloon-pumping followed by cardiac retransplantation.

A 37-year-old man underwent cardiac transplantation for diffuse coronary artery disease and malignant arrhythmias. During the harvesting of the donor heart slight distention of the left ventricle was present due to insufficiency of the aortic valve. After explantation of the graft, fusion of 2 cusps was found and a commissurotomy of the aortic valve was performed and the graft transplanted. Despite maximum inotropic support immediate graft failure and aortic insufficiency was present and discontinuation of cardiopulmonary bypass (CPB) was impossible. After replacement of the aortic valve using a bioprosthesis and implantation of an intraaortic balloon-pump, low cardiac output persisted and CPB had to be continued. After 11 hours of normothermic cardiopulmonary bypass and intraaortic balloon-pumping a second graft became available and was retransplanted successfully. The postoperative course was uneventful and the patient remains well 3 months after the operation.

Adult↗
PubMed1986

Successful surgical treatment of focal atrial tachycardia--a case report and review of the literature.

Focal atrial tachycardia with frequencies up to 200/min in an 11-year-old girl had been resistant to drugs over a period of 5 years. An electrophysiological study demonstrated a left atrial ectopic tachycardia. Intraoperative epicardial mapping localized the automatic focus at the base of the left atrial appendage. Excision of the appendage and cryoablation of the adjacent area were performed using cardiopulmonary bypass. Histologic examination of the excised tissue showed no specific alterations aside from islets of fatty tissue. The girl has been in sinus rhythm and has shown no tachycardias during the 6 months following the operation. A review of the literature, covering 17 cases of right and 12 cases of left atrial focal tachycardia, indicates excision of the atrial tissue in combination with cryoablation to be the treatment of choice to ensure success.

Child, Preschool↗
PubMed1986

[Unstable angina pectoris: disease picture and study of its course].

The object of the present study is to analyse the history of patients with typical unstable angina. For this purpose the data of all patients admitted to the Hannover Medical School between 1977 and 1983 and taken to the CCU because of proven unstable angina (history, duration of symptoms, intrahospital mortality, incidence of infarction, medical or surgical therapy, coronary pathomorphology, mortality after release from hospital, late incidence of infarction and rehospitalization) were documented and stored on a data bank for statistical analysis. 123 patients were entered into the study (97 males, 26 females; average age 58.4 +/- 9.2 years); during hospitalization all patients had angina at rest, 94% had transient ECG-changes (ST-segment changes, BBB etc.). The average follow-up was 4.2 +/- 2.0 years. 80 patients of the whole study population were treated medically, 43 underwent early bypass surgery. The two groups were different with respect to coronary pathomorphology (number of diseased vessels) as well as left ventricular wall motion, which was significantly more impaired in the surgical group (p less than 0.05). The hospital-mortality in the surgical group amounted to 9.3% (n = 4), the incidence of infarction to 18.6% (n = 8); the hospital mortality in medically treated patients was 2.5% (n = 2), the incidence of infarction 7.5% (n = 6). During the whole study period (average follow-up 4.2 years) the overall mortality amounted to 21%, the infarction rate was 23.5%: The cumulative survival rates revealed no significant difference between the 2 groups: after 3 years 84% of all patients were still alive, 65% without new infarction during the observation period; the rate of rehospitalization amounted to 50%. At the end of the study class III or IV angina (NYHA-criteria) was much more common in the medically treated than in the surgically treated group (NYHA mean 2.5 versus 2.0; p less than 0.5). The relatively high rate of perioperative death and myocardial infarction in the surgical group is based on the selection of patients according to coronary pathomorphology and the clinical status.

Angina Pectoris↗
PubMed1986

[Surgical therapy of intracardiac infected pacemaker electrodes and catheter remnants].

With the increase of pacemaker and central venous catheter implantation the number of intracardiac infections now constitutes a significant problem. Twenty patients between 22 and 77 years of age admitted for intracardial infected pacemaker probes or central venous catheter remnants presented with recurring attacks of endocarditic fever; in one case multiple pulmonary abscesses resulted from septic embolization. Staphylococci were the most frequently involved organism (75%). Risk factors leading to intracardiac infection were local reoperations and diabetes mellitus. Removal of the foreign body was achieved by cardiotomy in all cases. Twelve patients were operated upon without the use of the heart-lung machine, but extracorporeal circulation was necessary in 8 patients. There was one fatality in each of the 2 techniques, for a total mortality rate of 10%. In all cases the foreign bodies were removed without intracardial damage and the endocarditis was cured. When attempts at external extraction fail, the foreign body should be removed by either open or closed cardiotomy. This limits the danger of injury to the heart and of embolization of septic or thrombotic material. The use of the heart-lung machine is especially indicated in the presence of widespread, firm adhesions, or large bacterial vegetations and thrombi.

Abscess↗
PubMed1986

The mechanism of spinal cord injury after simple and double aortic cross-clamping.

Ischemic spinal cord injury after cross-clamping of the descending aorta can occur independently of aortic disease. In a previous study we had shown a precipitous uniform fall of spinal surface oxygen tension downstream to the clamping site irrespective of level. In the present paper, the hemodynamic changes in the spinal and aortic collateral circulation were investigated. Pressures were measured in the proximal, distal, and excluded aortic segments (descending thoracic and lumbar aorta) as well as in the intercostal and the lumbar arterial beds. Before high aortic occlusion, pressures in the intercostal and lumbar arterial beds were lower than aortic pressure. Along with the postclamping fall in distal arterial pressure, intercostal and lumbar arterial bed pressure decreased further but remained above aortic pressure. Exclusion of the thoracic aorta by double clamping restored intercostal bed pressure almost to control, whereas exclusion of the abdominal aorta hardly affected lumbar bed pressure. We conclude that spinal collateral circulation is more highly developed in the thoracic than in the lumbar region. After aortic cross-clamping, blood tends to drain away from the spinal cord rather than supplying it longitudinally. Under clinical conditions, therefore, retrograde bleeding into the opened aorta as well as into the aorta downstream to the distal clamp should be minimized and larger vessels originating from the aorta should promptly be anastomosed to the graft.

Animals↗
PubMed1986

[Choice of heart valve prosthesis--1985].

Improvement of materials, prosthetic function and perioperative treatment has led to positive results with regard to life expectancy, quality of life and complication rates in heart valve replacement. While mechanical valves are still associated with the risks of thromboembolism and anticoagulant bleeding, there is a continuing risk of early valve dysfunction in bioprostheses. We have preferred the latter during the last 8 years; however, certain disadvantages have become obvious during the follow-up of a group of 132 patients beyond the 6th postoperative year. Anticoagulant treatment has been withheld in some patients in spite of a clear indication while others have received coumadin in the absence of obvious reasons. Valve degeneration as discovered by echocardiography often was not recognized in time, resulting in a significant reoperative mortality. As a result the indication for biological valve replacement, especially in the mitral position, has become more restrictive in our hands.

Anticoagulants↗
PubMed1985

Lumbar and thoracic spinal cord oxygen tension during aortic cross-clamping.

In order to investigate the changes in tissue oxygen and the efficiency of the collateral circulation in the different regions of the spinal cord (SC) during aortic occlusion, surface PO2 (sPO2) was measured on the exposed SC in the pig in the lumbar (L3-5) as well as in the thoracic (Th6-8) parts before, during and after a 45 minute occlusion. The pigs were divided into two groups: group IA: cross-clamping of the aorta immediately below the left subclavian artery; group II: occlusion of the aorta immediately above the arteria radicularis magna anterior (ARMA). In response to occlusion, the sPO2 distal to the occlusion always decreased significantly (group IA: mean lumbar sPO2 from 42.3 mm Hg to 3.2 mm Hg, mean thoracic sPO2 from 34.9 mm Hg to 3.9 mm Hg; group II: mean lumbar sPO2 from 28.0 mm Hg to 7.9 mm Hg). Mean thoracic sPO2 in group II remained constant. No statistically significant differences between the distal regions could be established. The collateral circulation in the thoracic as well as in the lumbar region was insufficient at least during occlusion.

Animals↗
PubMed1985

[Surgery of abdominal aortic aneurysm--results in 502 patients].

Between 1975 and 1985 502 patients (52 female, 450 male, aged 29 to 88 years, mean 66 years) were operated for abdominal aortic aneurysm (AAA). In 261 electively operated patients hospital mortality was 4.9% (group A). In 79 patients with impending rupture the rate was 12.2% (group B) and of 125 patients with a ruptured AAA 46.6% died (group C). Of 42 patients with thoraco-abdominal aneurysm (group D) 11 had a rupture. Mortality was 66%. These figures could be improved. Between November 1983 to the end of 1984 in group A lethality was 4.1% (2/49), in group B 6.25% (1/16), in group C 33% (8/24). Of the last 4 patients of group D operated electively 1 died. Reasons for this improvement were: 1. improved anesthesiological management, 2. use of graft-inclusion-technique, 3. implantation of straight tube grafts instead of bifurcated prostheses, 4. use of collagen-coated Dacron prostheses.

Aorta, Abdominal↗