Biomedical subjects

A Harjula

Publications and source records attributed to A Harjula.

At least 91 records · Page 5Linked to original sources

PubMed1984

Sequential internal mammary artery (IMA) grafts in coronary artery bypass surgery.

Since 1972, double or triple left IMA bypasses have been made on 61 consecutive patients with a total of 123 distal anastomoses to the LAD or to the LD branches of the LAD. There were 54 additional vein grafts with 102 distal anastomoses. The number of single IMA grafts in the same period of time was 400. Hospital mortality was 2 patients (3.3%), with a late mortality of 7 patients (11.3%), 2 of them being heart-related, one of hypernephroma, one suicide, and of unknown cause in the remaining 3 patients. Five patients refused postoperative angiography. There were 50 patients with one or more postoperative angiograms available for the analysis after a mean follow-up time of 35.1 (0.5 to 128) months. The late patency of the left IMA anastomoses was 97% (98/101) and 82.4% (84/102) of the vein anastomoses. There were 2 anastomotic left IMA occlusions to the LD at 2 weeks and 10 months, respectively, and to LAD at 13 months. No left IMA graft had become completely occluded. According to the trend analysis, there was a 97.5% patency at 5 years, and 95.7% at 10 years with left IMA grafts compared to 78.4 and 67.9, respectively, with vein grafts. Ten left IMA grafts were dilated, 2 narrowed and 36 unchanged at the late angiography. Sequential left IMA graft, in appropriate cases seems to result in the most superior patency rate of all types of grafts.

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PubMed1984

Cardiac tamponade and different modes of artificial ventilation.

Cardiac tamponade after open-heart surgery often occurs in a situation when the patient is still mechanically ventilated and needs circulatory support with catecholamines. To evaluate the effects of different modes of artificial ventilation and dopamine on cardiac tamponade, an experimental study was carried out in seven mongrel dogs. In pentobarbital - N2O anaesthesia, a cardiac tamponade of 20 mmHg was produced by injecting 120-200 ml of normothermic saline into the pericardium. Intermittent positive pressure ventilation (IPPV) and positive end-expiratory pressure (PEEP) ventilation with frequencies of 12 and 20 were tested before and after producing the tamponade. Cardiac tamponade produced a significant fall in arterial pressure and cardiac output, a significant rise in central venous pressure and only a slight increase in pulmonary arterial pressure. PEEP with the slower ventilation frequency of 12 produced additional, significant falls in cardiac output and systemic arterial pressure, which were not noted with the ventilation frequency of 20 and PEEP. Dopamine infusion increased the cardiac output by increasing the heart rate during tamponade. It is concluded that PEEP ventilation with a slow frequency should not be used if cardiac tamponade is suspected after open-heart surgery, and that dopamine has a favourable effect on haemodynamics even in the presence of a severe cardiac tamponade.

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PubMed1984

Combined valve replacement and myocardial revascularization. Factors influencing early and late results.

The risk factors involved in simultaneous valve replacement and coronary artery bypass grafting were evaluated in 54 consecutive patients, 42 men and 12 women, aged 22 to 73 years. The predominant valve anomalies were aortic stenosis (30 patients), aortic regurgitation (9), mitral regurgitation (10) and mitral stenosis (5). All the patients had angina. Myocardial infarction had occurred in 22 cases and was impending at the time of operation in 10. The diseased valves were replaced with mechanical prostheses, and on average 2.5 coronary arteries per patient were bypassed with vein or with internal mammary artery grafts. Four of the 54 patients died in association with surgery, and four more during follow-up (0.5-6 years). The operative mortality was 2/39 in the aortic valve group and 2/14 in the mitral valve group. The late mortality was equal in both groups. A relatively small ejection fraction and long aortic cross-clamping were the only factors which attained statistical significance as surgical risks, but mitral regurgitation due to ischaemic papillary muscle dysfunction, advanced rheumatic mitral regurgitation and tight aortic stenosis combined with coronary artery disease also seemed to be indicators of poor prognosis.

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PubMed1984

Primary malignant melanoma of the oesophagus. A case report.

A primary malignant melanoma of the oesophagus was surgically treated in a 71-year-old man. Maximally radical excision of the tumour was performed, with broad 'safety' margins and radical ablation of the para-oesophageal tissue at tumour level, without touching the tumour. When oesophagoscopy shows a tumour strongly suggestive of melanoma, confirmation should be made with fine-needle aspiration biopsy in preference to histologic biopsy, to avoid explosive spread of the tumour.

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PubMed1983

Postoperative median sternotomy dehiscence.

An analysis of the records of 2130 patients who consecutively underwent median sternotomy with or without cardiopulmonary bypass showed that sternal insufficiency necessitating refixation of the sternal plates developed in 12 patients (0.56%). This complication arose during the initial hospital stay in 11 patients, but in one patient the sternal instability appeared about a year after the operation. Re-exploration showed interruption of the stainless steel wires in six cases. In the other cases the wires had loosened, or knots had opened, or wires had cut through the sternal bone. All 12 patients had undergone open-heart surgery. The commonest risk factors for sternotomy dehiscence were excessive blood loss with heavy transfusion requirements, and postoperative wound infections. Other factors were respiratory complications and postoperative ventilatory support, low cardiac output syndrome, chronic obstructive pulmonary disease and obesity. Careful closure of the sternum, using figure-of-eight sutures if necessary, and avoidance of excessive application of bone wax are important for preventing this harmful complication.

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PubMed1983

Fistula between abdominal aortic aneurysm and left renal vein.

A 77-year-old man with spontaneous rupture of an abdominal aortic aneurysm into the left renal vein, in the presence of an anomalous retroaortic left renal vein is described. The patient was operated and recovered without complications. In the previous literature seven similar cases were found.

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PubMed1982

Surgical intervention in cases of Ebstein's anomaly. Abnormal origin and structure of the tricuspid valve.

During the ten-year period 1972-81 four patients, two men and two women, with Ebstein's disease underwent operation at our institution. Their average age was 34. Central cyanosis at rest, clubbing and polycythaemia were the most common clinical features of the patients. Enlarged heart, a small pulmonary arterial arch and transluminal lung fields were seen in chest X-ray. Operative findings were a grossly enlarged right atrium and ventricle, the latter having a segment that was typically atrialized and thin-walled but was contracting synchronously with the true right ventricle, and a wide variation in the leaflets of the tricuspid valve and their origins. The atrial septal defect was small in all cases. Artificial heart valves (1 Cutter-Smeloff, 2 Björk-Shiley, 1 St. Jude) were used in the tricuspid reconstruction in addition to closure of the ASDs. One of the patients died postoperatively, the other three are doing well.

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PubMed1982

The effects of a centrifugal pump as a left-ventricular-assist device in myocardial infarction.

Cardiogenic shock after acute myocardial infarction and open heart surgery having cardiopulmonary bypass may present a difficult clinical problem with high mortality. The present study was carried out to evaluate a newly developed laminar flow centrifugal pump as a left-ventricular-assist device to support the circulation and prevent myocardial damage in such situations. Experimentally induced acute myocardial infarction in dogs was used as the model. Cardiogenic shock was effected by ligating enough branches of the left coronary artery. In addition to recording the haemodynamic parameters, samples of myocardium were taken with a biopsy needle from the infarcted area, transitional zone and intact myocardium for determination of adenosine triphosphate, creatine phosphate and lactate. In the first phase of the work the effects of acute myocardial infarction on haemodynamics and high-energy compounds were defined, to form a basis for the evaluation of the pump as left-ventricular-assist device. Ligation of the branches of the left coronary artery produced a rapid fall in aortic pressure, cardiac output and cardiac performance, elevation of ST-segment in the ECG and fall in high-energy compounds. However, there was a marked spontaneous recovery in the transitional zone within 120 min, despite the haemodynamic deterioration. The laminar flow pump produced a significant improvement in the haemodynamic and metabolic parameters which exceeded the spontaneous changes noted previously.

Adenosine Triphosphate↗

PubMed1981

Human umbilical cord vein as arterial substitute in the dog.

The aim of this study was to compare human umbilical cord vein grafts (HUCV), treated in different ways, as arterial substitutes in the dog. A portion of the infrarenal abdominal aorta was replaced by a fresh HUCV in 18 dogs. Six HUCV grafts were covered with a vascular dacron prosthesis, 4 of them stayed open during a follow-up time of one year, 2 became occluded. Within an interval of 4 weeks, aneurysms developed in the uncovered 12 HUCV grafts. They also thrombosed within 3 months. The infrarenal abdominal aorta was replaced by HUCV grafts treated with glutaraldehyde in 39 dogs. Within a follow-up time of six months, all grafts were patent and no aneurysm formation could be observed. Eight biografts were compared with eight PTFE grafts ileofemoral positions. Six Biografts as well as six PTFE grafts were patent after six weeks.

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PubMed1981

Glutaraldehyde pre-treated human saphenous and umbilical veins as xenogeneic small vessel substitutes and shunts in dogs.

A total of 84 grafts 100 mm in length was inserted as arterial and shunt conduits in 31 mongrel dogs. There were 24 glutaraldehyde pre-treated vein bypass grafts, 15 glutaraldehyde pre-treated vein shunt grafts, 9 fresh, untreated vein bypass grafts, 10 combined teflon-glutaraldehyde pre-treated vein shunt grafts, 11 glutaraldehyde pre-treated umbilical vein shunt grafts, 11 glutaraldehyde pre-treated umbilical vein bypass grafts, 4 dacron mesh covered modified umbilical vein bypass grafts. The internal diamter was 4 mm in all the saphenous vein grafts and in seven of the umbilical vein grafts and 6 mm in all other grafts. After an implantation period of 0.5--2.5 months, 5 of the 24 glutaraldehyde pre-treated saphenous vein bypass grafts were patent, and the rest thrombosed. These grafts were very adherent to surrounding structures. Glutaraldehyde pre-treated saphenous vein shunt grafts occluded within 2.5 months. Combined teflon-glutaraldehyde pre-treated saphenous vein shunt grafts functioned better, 6 of 10 grafts being patent after 4.0--6.0 months. Eight of 9 fresh grafts were thrombosed within one month. Eleven glutaraldehyde pre-treated human umbilical vein bypass grafts were followed up for 5.0 months and both those with a 4 mm internal diameter and those with 6 mm functioned well. Glutaraldehyde pre-treated human umbilical shunt grafts also functioned well up to 5.0 months. Reactive changes were minimal around umbilical grafts.

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PubMed1980

The effect of glutaraldehyde-tanning on the elasticity of the human saphenous vein.

The elasticity of eighty-one vessel samples was evaluated by a tensile strength test. Twenty of these were untreated veins, 24 glutaraldehyde-pre-treated veins, 16 pre-treated implanted veins and 21 untreated arteries. The artery was the most elastic vessel. Glutaraldehyde-pre-treatment diminished the elasticity of veins, but added tensile strength. Insertion of glutaraldehyde-pre-treated human veins into carotid arteries of dogs did not alter the elastic properties of these grafts.

Animals↗

PubMed1980

Histological study of glutaraldehyde-processed vascular grafts of biological origin.

A total of 90 grafts of 100 mm in length was inserted as arterial and shunt conduits in 31 mongrel dogs. Histological changes before and after implantation were evaluated. Sections were stained with van Gieson, haematoxylin eosin and Wiegert's method for elastic fibres, and studied with light microscopy. Twenty five of the 42 cases studied showed classic signs of rejection around the graft, the strongest immunological response being seen in the fresh vein grafts. Glutaraldehyde pre-treatment diminished this reaction but it was still clearly visible in 13 of the 21 cases. Of the fourteen human umbilical vein grafts tanned with glutaraldehyde and used either as shunts or bypass grafts, seven showed only slight or moderate reaction and in seven cases no clear sign of rejection could be seen. The absence of intimal hyperplasia with this type of graft also showed its superiority over that of the human "non-umbilical" vein grafts. The problem in all the groups was the anastomotic area, where fibrous hyperplasia developed. The graft structure seemed to be well-preserved during the follow-up period of 6.0 months.

Animals↗

PubMed1980

Morphological study of flow surface of glutaraldehyde pre-treated vascular substitutes.

90 grafts were inserted as arterial and shunt conduits in 31 dogs. Human saphenous veins and umbilical veins were either fresh or treated with 0.2% v/v glutaraldehyde. 72 samples from these grafts were studied morphologically. Macroscopic inspection, and light, scanning and transmission microscopy was used. The insertion time of the grafts were kept in place for periods up to 6.0 months. The tanning procedure with glutaraldehyde destroyed all normal endothelial structures. However, the new vascular interface appeared to be quite thrombo-resistant, because only slight changes were found on the flow surface following surgery. Multiple collagen fibres were seen with fibrin like deposits predominating. In those grafts which were thrombosed the thrombus had its origin at the anastomotic site and the graft itself was free of thrombus. No endothelium could be seen in any case studied. Fresh untreated saphenous vein grafts studied as controls showed clear degenerative changes and thrombus accumulation on the inner surface. The same kind of changes were found also in the anastomosing artery.

Animals↗

PubMedDate not supplied

Sequential CT in monitoring experimental lung transplant.

The criteria for diagnosis of lung rejection remain controversial. In this study early changes in lung rejection were characterized using sequential CT with the aim of developing a sensitive and safe monitoring method, which would also provide specific information on graft status. Twenty-one experimental single lung transplants (SLTs) in piglets, including unmodified rejections, immunosuppressed recipients, and autogenic reimplants, were scanned using CT on days 3, 5, 7, 10, 14, 22 up to 134 days after operation. In addition to morphological analysis, bilateral densitometric CT measurements of the peripheral lung parenchyma were used to evaluate the intensity of interstitial infiltration of lung grafts. Altogether 67 postoperative CT studies were carried out. Simultaneous transbronchial/thoracic biopsies were undertaken. The mean follow-up time was 28 days (range 0-134 days). The experience obtained was then used in relation to SLT in a male patient for chronic obstructive pulmonary disease. All piglets had a typical hilar reimplantation response, which disappeared in 10-20 days. Two distinct patterns of radiological acute rejection were found. Increasing peripheral alveolar infiltrates reflected early massive rejection in untreated animals. In immunosuppressed animals, after the initial reimplantation response, acute rejection was detected as densitometrically measured diffuse interstitial infiltration over the whole graft. Local findings, like focal infections, were seen later in the lingula and basal portions of the graft. In the SLT patient, density changes preceded clinical rejection episodes, which responded to steroid therapy. In the experimental study, the lung graft was compared to normal contralateral lung. In the SLT patient, however, this was not possible, and, therefore, the subsequent repeated CT studies formed the basis of clinical follow-up. Sequential imaging and densitometric measurements allowed objective estimation of diffuse interstitial infiltration relating to rejection.

Animals↗

PubMedDate not supplied

Early and late results of surgery for atrial septal defect in patients aged over 60 years.

To assess the risks and benefits attending the surgical repair of atrial septal defect in the elderly the case histories of all patients operated on at the age of 60 years or more were reviewed and follow-up study, including cardiac catheterization, was performed. A total of 17 patients (12 females and 5 males) were identified. The left-to-right shunt ratio averaged 2.7. Fifteen patients had abnormally high systolic (greater than 30 mmHg) or mean (greater than 20 mmHg) pulmonary artery pressure and the pulmonary arterial resistance was elevated (greater than 1.5 units) in eight. One patient died shortly after surgery (operative mortality, 6%) and major postoperative complications were found in four additional patients (24%). Three months after surgery the effort capacity had improved by at least one class in all survivors. After an average of 8.2 years follow-up 12 patients were alive. Ten of them felt better than preoperatively. Eight agreed to cardiac catheterization. The pulmonary blood flow was markedly decreased in all (means, 5.6 l/min postoperatively, vs 11.2 l/min preoperatively) even though a hemodynamically significant shunt persisted in two patients. The mean pulmonary artery pressure had decreased in all who were hypertensive before operation (mean, 25 mmHg vs 33 mmHg). It had slightly increased in patients who had normal pulmonary pressure preoperatively (mean, 27 mmHg vs 19 mmHg). The pulmonary arterial resistance was higher than before surgery in all except one patient (mean, 2.2 units vs 1.5 units).(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMedDate not supplied

Effect of addition of magnesium to potassium-containing fluorocarbon cardioplegic preparations. An experimental study.

The effect of magnesium on potassium fluorocarbon cardioplegia was studied in 20 rabbits. Isolated hearts with ascending aortas were perfused with oxygenated and cooled (+4 degrees C) fluorocarbon solutions. In 10 experiments, the solution contained 20 mmol/l of potassium, in 10 further experiments, 20 mmol/l of potassium and 15 mmol/l of magnesium. Ultrastructural preservation of the myocardium was studied using transmission electron microscopy. In addition, the cation contents of the myocardium were studied by flame atomic absorption spectrophotometry (calcium, magnesium) or electrothermal atomic absorption spectrophotometry (copper). After 120 minutes of ischaemia, areas of moderate or severe ultrastructural myocardial cell damage were observed in both groups but severe damage was more extensive and commoner in the group with no access to magnesium. Preservation of the capillary endothelium was also worse in that group. There was a highly significant increase in magnesium content, a decrease in calcium content and an increase in the magnesium/calcium ratio following magnesium-potassium fluorocarbon infusion. The copper content remained unchanged. A protective effect of magnesium was observed. The electrolyte content of cardioplegic solutions also alters the electrolyte content of the myocardium. This may be important in reperfusion.

Animals↗

PubMedDate not supplied

Comparative effect of cyclosporin A and G on weight gain of primates during the pubertal growth period.

A double-blind study with six cynomolgus monkeys (mean age, 2.0 years) was carried out. All animals received immunosuppression therapy with 16 mg/kg/day of cyclosporin A or G (Norvaline cyclosporine), given intramuscularly in two divided daily dosages. All animals received a small dosage of steroids (0.1 mg/kg/day). After 14 months the dosage of cyclosporin G was increased to 20 mg/kg/day. During the first study year, weight velocity was normal in the cyclosporin G group and impeded in the group receiving cyclosporin A. During the second year of the study, the weight velocity was impeded in both groups. The weight gain was significantly less in the cyclosporin A group than in the group receiving cyclosporin G (p = 0.001). The results suggested that cyclosporine impeded weight gain in primates during the pubertal period. The effect was dosage-related and was less with cyclosporin G than with cyclosporin A. The mechanism is unclear, but the possible effect on the growth hormone merits further studies.

Animals↗

PubMedDate not supplied

Experience with arm veins as aorto-coronary bypass grafts.

In a series of 1,000 coronary bypass operations 15 patients received arm vein grafts. In these cases the saphenous veins were either absent or inadequate and the mammary arteries alone were not sufficient for multivessel coronary revascularization. Altogether, 34 coronary anastomoses were performed with 16 arm vein grafts; additional coronary endarterectomy was needed in four instances. Together with mammary artery or saphenous vein grafts these patients each had, on the average, 3.6 coronary anastomoses. There was no operative mortality and no complication related to the arm vein grafts. Postoperatively all the patients were free of angina pectoris. A follow-up angiogram (mean 1.4 years postoperatively) showed a patency rate of 87% for arm vein grafts. A frequent finding was an uneven diameter of the grafts. In three patients aneurysmal dilatation (of 8.3 to 9.8 mm in diameter) was revealed. Although the patency rate to date is satisfactory, our experience is too limited in time numbers to judge long term durability.

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