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Biomedical subjects

E Merikallio

Publications and source records attributed to E Merikallio.

At least 19 recordsLinked to original sources
PubMed1989

Intracellular-type solution flush for preservation of myocardium and coronary and pulmonary artery flow surface.

Modified Euro-Collins solution (ECS), which has been successfully used in kidney, liver and lung transplantation, was tested concerning myocardial and endothelial preservation in nine piglets. In six (group I), 1-hour cardiac arrest was induced with cold modified ECS, and in three (group II) heart-lung transplantation was performed, using modified ECS for graft preservation. In group I myocardial energy preservation was determined with biochemical assays for adenosine triphosphate, creatine phosphate, lactate and creatine 5, 15, 30 and 60 minutes after aortic clamping, and preservation of endothelium in the aorta and coronary arteries was studied with scanning electron microscopy. In group II electron microscopy was performed on endothelial samples from the ascending aorta and coronary and pulmonary arteries of the heart-lung block after excision, after 2 hours of ischemia, and after 1-2 hours of reperfusion. High-energy phosphates decreased progressively during the ECS cardioplegia in group I, and circulatory support was required during the post-transplantation reperfusion period in group II. The endothelial lining in all specimens was remarkably well preserved, however. Modified ECS flush thus was ideal for vascular endothelium but, because of its poor energy-preserving capacity, unsuitable for cardioplegia.

Animals↗
PubMed1989

The possibility of using celiac trunk branches as coronary artery bypass grafts.

The internal mammary artery has proved to be superior to the saphenous vein for coronary artery bypass grafting, because of its arterial nature and closer approximation in size to the coronary arteries. But the internal mammary artery cannot reach the posterior surface of the heart as a pedicled graft. Two suitable intra-abdominal grafts can reach that surface, viz. the right gastroepiploic artery and the splenic artery. In experiments on eight dogs (weight 9-13.5 kg), the gastroepiploic artery was found to be too small for coronary artery anastomosis, and therefore the splenic artery was used. The size approximation with coronary artery (diameter less than 1 mm) was good. Four dogs survived the month of the study. In two of them the anastomosis was patent, in another the splenic artery was patent despite occlusion of the anastomosis, and in the fourth dog both anastomosis and graft were thrombosed. The possibility of using visceral arterial grafts in coronary surgery is discussed.

Anastomosis, Surgical↗
PubMed1987

Cardiorespiratory function after correction of tetralogy of Fallot. Modifying effect of previous shunt operation.

Of 28 patients with total surgical correction of tetralogy of Fallot in adult life, 22 had previously undergone Blalock-Taussig shunt operation. Possible modifying effects of the shunt on pulmonary ventilation and perfusion and on exercise tolerance were investigated with spirometry, radiospirometry and bicycle ergometry. The observed ventilatory volumes and capacities and diffusing capacity were significantly lower than the predicted values. Vital capacity was significantly reduced in patients with adverse NYHA or haemodynamic classification. Between the various NYHA or haemodynamic groups no statistically significant difference was demonstrable in pulmonary function or diffusing capacity or in airway resistance. Ventilatory obstruction was found also in patients without previous shunt. Other lung function tests showed no significant difference between the shunt and the non-shunt group. Nor was distribution of lung perfusion significantly affected by shunt. No correlation was seen between lung function and bicycle ergometric findings. However, in non-shunt patients who had ventilatory obstruction or impaired diffusing capacity, exercise tolerance was significantly higher than in patients who had had palliative shunt.

Adult↗
PubMed1987

Correlation of NYHA classification, bicycle ergometry and right heart haemodynamics after total correction of tetralogy of Fallot in adults.

Thirty-two patients who had undergone correction of Fallot's tetralogy in adult life were examined on average 6.3 years postoperatively, at mean age 25.8 years. Palliative shunt operation had been performed in childhood in 28 cases. The clinical condition was good in 25 patients (78%). 13 of whom had mean gradient between right ventricle and pulmonary artery 16.0 +/- 4.2 mmHg and systolic right ventricular pressure 39.0 +/- 10.0 mmHg, while 12 had right ventricular pressure 62.6 +/- 16.3 mmHg. In these groups the maximum exercise capacity was, respectively, 136.7 +/- 36.1 and 106.1 +/- 30.8 W/min. Three other patients were in satisfactory, and four in poor clinical condition, with right ventricular systolic pressure, respectively, 74.3 +/- 10.9 and 91.5 +/- 60.0 mmHg. The gradient from right ventricle to pulmonary artery averaged 58.5 +/- 10.4 mmHg in the latter group but, despite the obstructed pulmonary outflow tract, the exercise capacity (116.7 +/- 28.9 W/min) was similar to that in the groups with better clinical results. It is concluded that in most patients with palliative surgery in childhood, tetralogy of Fallot can be successfully corrected in adult life. The causes of right ventricular impairment do not significantly reduce the exercise capacity.

Adult↗
PubMed1986

Effects of synthetic blood combined with contrast medium on coronary endothelium: an experimental study.

The study described was carried out to evaluate endothelial injury following incubation of coronary material in contrast medium and in contrast medium diluted with fluorocarbon solution. Six porcine hearts were excised and isolated. Immediately thereafter, pieces of the main coronary arteries and ascending aortas were incubated in four different solutions: 1) blood, 2) contrast medium, 3) fluorocarbon solution, 4) fluorocarbon--contrast medium (1:1). Flow surfaces and coronary endothelial morphology were evaluated by scanning electron microscopy (SEM). Porcine blood (at room temperature) preserved endothelial structures intact but, in two samples, small patchy areas of denuded surface were found. Four minutes' immersion in contrast medium resulted in easily visible changes in the endothelial lining and individual cells. Denuded flow surface areas were common, the intact surface morphology was flattened. After 7 minutes, destruction was total. The addition of fluorocarbon solution to contrast medium (1:1) diminished the changes, which also occurred later than after incubation in pure contrast medium. After 7 minutes, separate endothelial cells were still identifiable but the microvilli had disappeared. Fluorocarbon solution preserved the endothelial lining well during a 10-minute follow-up period. The experimental protocol described confirmed the deleterious effect of contrast medium on coronary endothelial lining, which could be reduced to some extent by adding fluorocarbon solution to contrast medium.

Animals↗
PubMed1986

Hospital cost development in coronary bypass surgery.

The rapid expansion of open-heart surgery together with steadily rising costs of health services has elicited criticism against uncontrollably expanded costs of coronary bypass surgery. However, critical analyses of the cost structures and the attempts for cost containment can only rarely be found in medical literature. This study emphasizes self-evident surgical principles which have led to surprisingly high cost reductions. Further savings can be obtained by constant financial education of the surgical staff, in spite of some controversial experiences gained elsewhere. The conditions needed are more accurate, up-to-date hospital bookkeeping and closer contacts between the hospital administration and the medical staff.

Coronary Artery Bypass↗
PubMed1985

Effects of synthetic blood and crystalloid cardioplegic solutions on coronary endothelium: an experimental scanning electron microscope study.

In an experimental study the effects of Fluosol DA (added with potassium chloride) on the vascular interface and endothelial cells were compared to those of crystalloid potassium cardioplegic solution using scanning electron microscope. Twenty rabbits (10 in each group) were sacrificed, the hearts with ascending aorta were immediately excised, and cold oxygenated solution was infused via a cannula inserted into the cross-clamped aorta. The hearts were left immersed in the perfusion medium for 2 hr. In the Fluosol DA group endothelial cover and endothelial cells were normal or minimal changes were seen in seven cases. Occasional breaking of intercellular attachments, small areas of denuded flow surface, and disappearance of microvilli were seen in three cases. In the crystalloid potassium cardioplegic group 7 of the 10 cases showed moderate or severe damage with large areas of denuded flow surface. The present experimental protocol represented an extreme situation where no collateral coronary blood was present. The coronary endothelial damage was obvious after the crystalloid potassium cardioplegic solution. Similar damage was not found following Fluosol DA infusion.

Animals↗
PubMed1985

Cardioplegic protection with hypothermic K-Fluosol DA and K/Mg-Fluosol DA solutions.

Oxygenated fluorocarbon cardioplegic solution was tested in 20 isolated rabbit hearts. In 10 of the hearts, 150 ml of solution (Fluosol DA) with addition of 20 mmol/l potassium, 4 degrees C, was infused during 3 min into the aortic root (infusion pressure 60-80 mmHg). The other 10 hearts were perfused with Fluosol DA containing 20 mmol/l potassium and 15 mmol/l magnesium. The hearts were left immersed in the perfusion solution for 2 hours. Myocardial biopsies were performed while the hearts were still beating, immediately after completion of the cardioplegic infusion and 60 and 120 min later. Transmission electron microscopy showed progressive, time-related deterioration of the myocardial cells, characteristic of myocardial ischaemia, in both groups. The changes, however, were clearly less pronounced in the K/Mg-Fluosol DA group. Myocardial capillaries remained patent in both groups throughout the observation period, but the capillary endothelium was better preserved in the K/Mg-Fluosol DA group. The study thus indicated that K/Mg-Fluosol DA was superior to K-Fluosol DA as a cardioplegic agent in terms of ultrastructural preservation of the myocardial cells and the endothelial lining of the myocardial capillaries.

Animals↗
PubMed1985

Effects of mitral valve replacement on ventilation, volumes, diffusing capacity and regional perfusion of lungs in patients with mitral valve disease.

The effects of mitral valve replacement on ventilation, lung volumes, diffusing capacity and regional perfusion of the lungs were studied in eight patients with long-standing mitral valve disease. Eight patients of the same age with coronary artery disease who underwent coronary bypass operation were tested as controls. Preoperatively, the patients with mitral valve disease had significantly higher perfusion of the upper lung fields and the ratio of residual volume to total lung capacity than the control patients. Vital capacity, forced expiratory volume in one second and maximal expiratory flow at 50% of vital capacity were lower in comparison with the control group. Seven days after open heart surgery the values of all the parameters mentioned above had decreased significantly from the preoperative levels in both groups. Three months post-operatively, the values returned to preoperative levels. The abnormal overperfusion of the upper lung fields and other derangements in the ventilatory pattern did not subside even though cardiac haemodynamics were corrected by mitral valve replacement.

Adult↗
PubMed1985

Direct hospital costs in coronary bypass surgery.

The direct hospital costs of 100 coronary artery bypass grafting operations are calculated. The basis of the calculations is the detailed, function-based, market-priced analysis of the files, including the hospital deaths, complication and reoperations of this patient group. The price of a CABG operation proved to lie somewhere between FIM 30,000 and 50,000, the mean value being FIM 46,800. The variation range is wide: FIM 18,200-FIM 249,500 (SD +/- FIM 26,000). It must be emphasized, however, that all preoperative hospital costs including coronary angiography costs and also postoperative follow-up hospital costs fall beyond this study.

Coronary Artery Bypass↗
PubMed1985

Acute renal failure related to open-heart surgery.

Open-heart surgery was performed on 1686 adult patients between 1980 and 1984. The patients were operated on using cardiopulmonary bypass procedures (CPB). Fifteen patients developed acute renal failure (ARF) after CPB, i.e. the incidence of ARF was 0.9%. All these patients were treated by peritoneal dialysis or haemodialysis. Pre-operative possible risk factors in the ARF group were compared to those in a control group of 30 patients (15 consecutive coronary artery bypass grafting and 15 consecutive valve repair procedures) experiencing no complications. Age, New York Heart Association (NYHA) classification, ejection fraction, cardiac volume and left ventricular end-diastolic pressure were not risk factors for the development of renal failure. The incidence of thrombocytopenia after CPB was statistically significantly different between the control and ARF groups. The mortality from ARF was 66.6%. The causes of death were peri-operative myocardial infarction, infection and gastrointestinal bleeding. CPB time, perioperative events and postoperative infection were the main factors contributing to ARF. Renal failure was twice as common in valve procedures as in coronary artery revascularization procedures. Impairment of renal function proved reversible only in those patients who survived. After restoration of renal function the prognosis was good.

Acute Kidney Injury↗
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.

Animals↗
PubMed1984

Unexpected urethral strictures after short-term catheterization in open-heart surgery.

Urethral stricture was found in 59 of 478 male patients who had undergone open-heart surgery between June 79 and December 81. In 40/59 cases the stricture showed a string-of-pearls configuration or long narrowing of the penile urethra on the urethrogram. Burning pain and dysuria were the main symptoms, and the urinary stream started to weaken immediately after the removal of the siliconized latex catheter which had been routinely inserted at the time of the heart operation and usually kept indwelling for 3 days. The stricture epidemic stopped after change of the latex catheters to silicone-ones. The different catheters were investigated for cell toxicity. Eluates of catheters were added at different concentrations to cultures of various cell lines. The cell proliferation was measured by thymidine incorporation. The results were uniform and showed marked toxicity of the latex catheters against all investigated cell lines.

Cardiac Surgical Procedures↗
PubMed1984

Total correction of tetralogy of Fallot in adults.

A series of 42 patients who underwent total correction of tetralogy of Fallot as adults is presented. Previous palliative operation had been performed in 33 cases: Blalock-Taussig shunt in 28 (bilateral in 6), Brock operation in four and Potts' anastomosis in one case. Severe cyanosis (average hemoglobin 203 g/l), thrombotic complications and hypoxic spells were the most pertinent of the clinical manifestations necessitating the total repair. Blalock-Taussig shunt had closed spontaneously before the intracardiac operation in 14 cases (3 bilateral) and in 11 it was ligated. In six cases the shunt was left untreated, being hemodynamically insignificant at operation. Three of the 42 patients died in association with the intracardiac operation. A-V block developed in two patients and required permanent pacemaker. During follow-up periods of up to 13 years, a residual ventricular septal defect was found in seven patients. Two of the defects were surgically closed. Five were not corrected, as the patients were doing well and the pulmonary/systemic flow ratio was less than 1.5 at repeat catheterization. Two-thirds of the patients were in NYHA class I at re-examination, and the others were in class II. The subjective functional improvement was greater than could have been expected from results of exercise tolerance tests.

Adolescent↗
PubMed1983

Perioperative myocardial infarction in coronary bypass surgery.

Thirteen of 199 consecutive patients undergoing coronary artery bypass surgery revealed definite perioperative myocardial infarction (PMI) in electrocardiography (ECG). The occurrence of PMI was not higher in the group of 44 patients who had intermittent aortic cross-clamping than in those patients treated with cold chemical cardioplegia. In 83 patients serum MB isoenzyme of creatine kinase (CK) and LD1 isoenzyme of lactic dehydrogenase were determined. Patients with unchanged ECG had peak CK-MB levels of 0 to 49 U/l (mean 18.7 U/l +/- 2.6 SEM) at 18 hours postoperatively while patients with PMI showed CK-MB levels of 64-350 U/l (mean 207 +/- 53 U/l); the difference was significant (p less than 0.01). In patients with unchanged ECG, LD1 was 139 +/- 19 U/l and 594 +/- 95 U/l in those with PMI (p less than 0.01). Risk factors for PMI were: age greater than or equal to 60 years, coronary endarterectomies, or cardiopulmonary bypass time greater than or equal to 100 minutes. One patient died of PMI while the remaining patients had postoperative courses comparable to those patients without PMI.

Adult↗
PubMed1983

Late aneurysms after patch aortoplasty for coarctation of the aorta in adults.

Sixty-eight patch aortoplasties were performed for coarctation of the aorta (CoA) in adult patients from 1967 to 1978 in our hospital. The mortality was 1.5% and the immediate result of the surgical repair seemed good. Long-term follow-up of 2 to 14 years later revealed aneurysm formation at the repair area in 27% of the 62 patients for whom sufficient follow-up data are available. Two aneurysms had ruptured with a fatal outcome. Other repair methods used for coarctation in 106 patients were free from aneurysm complication. Thirteen patients with an aneurysm underwent reoperation without mortality. The etiology of these unexpected aneurysms is discussed.

Adolescent↗
PubMed1983

Cardioplegia versus topical cooling for cardiac protection during open-heart surgery. An electron microscopic and histochemical study of right atrial biopsies.

The effectiveness of topical cooling and cold cardioplegia for cardiac protection in the course of open-heart surgery was studied by electron microscopy and fluorescence microscopy of right atrial biopsies. In 20 patients with topical cooling, no changes or minimal changes were observed in 15 cases, more pronounced changes in 3 cases, and severe destruction in 2 cases. In the group of 20 patients with cold cardioplegia the range of the changes was significantly narrower: no specimen remained completely intact; on the other hand, very severe destruction was not observed. Fluorescence microscopy revealed that the neural noradrenaline stores were relatively resistant to ischaemia. Electron microscopy showed certain failure of the protective procedure, resulting in injury of myocardial cells and neural elements. Even "spot-like" destruction noted in the nerve terminals may interfere with the peripheral neuro-neuronal interaction, resulting in nonhomogenous spread of the excitation wave front and electrical instability of the heart. Therefore cardiac nerve damage should also be taken into consideration when evaluating the effectiveness of different methods for cardiac protection.

Aortic Valve↗