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Biomedical subjects

M Turina

Publications and source records attributed to M Turina.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Heart surgery in acute heart infarct. Indications and results].

The therapy of acute myocardial infarction has made major advances in the last 10 years. Cardiac surgeons have to adapt their strategies to the more aggressive management of acute myocardial infarction. Only in mechanical complications of acute myocardial infarction is cardiac surgery nowadays the therapy of choice. In cardiac rupture and ventricular septal defect, surgery is the only therapeutic option. In ischemic mitral regurgitation, cardiac surgery is required in the event of concomitant cardiogenic shock and pulmonary edema after intra-aortic balloon pump placement. Coronary artery bypass surgery my be indicated at low risk in patients with unstable angina pectoris when PTCA is not feasible or has failed, or in catheter emergencies.

Acute Disease↗
PubMed1996

Toxoplasmosis in heart transplant recipients.

In cardiac transplant recipients, infection with Toxoplasma gondii may be transmitted with the transplanted organ to immunosuppressed recipients or may be due to reactivation under immunosuppression in cases of pretransplant infection. In the present study the incidence of infection with Toxoplasma gondii and the clinical presentation of the infection in 121 consecutive heart transplant recipients were investigated. Data on IgG and IgM antibodies for Toxoplasma gondii measured by a semiquantitative microparticle immunoassay of donors and recipients were collected prospectively in 121 patients. Infection with Toxoplasma gondii was defined as IgM seroconversion with proven pre-transplant seronegativity (primary infection) or at least a fourfold increase of IgG antibodies (reactivation). Infection with Toxoplasma gondii occurred in 16 of 121 patients (13%) whereas overt clinical disease occurred in 5 of 121 patients (4%). Organ-transmitted infection was more frequent (11/18, 61%) and more often associated with acute disease than reactivation of latent infection (5/69 patients, 7%) (p < 0.01), although one case of Toxoplasma retinochoroiditis occurred in a patient with recrudescence of latent pretransplant infection. Treatment with pyrimethamine and sulfadiazine was efficient in all patients with acute disease and in controlling disease in patients with evidence of acute infection.

Animals↗
PubMed1996

Endothelial cell seeding improves patency of synthetic vascular grafts: manual versus automatized method.

Lack of an endothelial surface is the most important variable causing the relatively poor patency of synthetic bypass grafts. This study was designed to investigate the effect of endothelial cell seeding on small-diameter Dacron grafts seeded with microvascular endothelial cells from omentum, and to evaluate two methods (manual vs automatized) for one-stage seeding in a canine carotid artery model. In 30 mongrel dogs microvascular endothelial cells were harvested from omentum, either by a manual or an automatized method, and seeded onto 6-mm internal diameter Dacron prostheses prior to the graft interposition into the common carotid arteries. Non-seeded Dacron grafts were used as control grafts. All dogs received dipyridamole (75 mg/day) and acetylsalicylic acid (325 mg/day) for 4 weeks. The prostheses were explanted between 2 and 26 weeks after insertion. The results were assessed by patency, angiography, light and scanning electron microscopy, transmission electron microscopy, and morphometry. Endothelial cell seeding improved the patency rate significantly, regardless of the seeding methods used. The overall actuarial patency rates at 5, 12, and 26 weeks were 98%, 94% and 94%, respectively, for the seeded Dacron grafts, and 92%, 62% and 54%, respectively, for the non-seeded grafts. The automatized method yielded more endothelial cells per gram of omental tissue than the manual method (P = 0.0002), but there was no difference (P = 0.34) between the seeding densities per square centimeter of the graft surface. The harvesting and seeding by the automatized method took 55 min for the whole procedure, 20 min less than the manual method. We concluded that one-stage endothelial cell seeding with omental microvascular endothelial cells improved the patency of small-diameter Dacron grafts in a canine model. The automatized method obtained excellent results comparable to the manual procedure, and also reduced the time necessary for the cell seeding.

Animals↗
PubMed1996

Surgery for ruptured thoracic and thoraco-abdominal aortic aneurysms.

OBJECTIVE: To assess the outcome of patients with ruptured descending thoracic and thoracoabdominal aortic aneurysms undergoing emergency repair, in comparison to elective surgery for chronic lesions. METHODS: A prospective study of 100 consecutive patients operated upon the descending aorta (1-8 segments) using proximal unloading and distal protection with partial cardiopulmonary bypass, heparin surface-coated perfusion equipment and low systemic heparinization (loading dose 100 IU/kg, activated coagulation time > 180 s), staged cross-clamping, sealed grafts and graft inclusion. RESULTS: Arteriosclerotic lesions were present in 53/100 patients (53%) for all, 30/53 (56%) for chronic, and 21/33 (63%) for ruptured, aneurysms (NS). Dissecting lesions were found in 38/100 patients (38%) for all, 20/53 (38%) for chronic, and 8/33 (24%) for ruptured aneurysms (NS). Preoperative hematocrit was 38 +/- 6% for all, 40 +/- 5% for chronic, and 33 +/- 5% for ruptured aneurysmal patients (P < 0.001 ruptured versus chronic). The extent of aortic repair (1-8 segments) was 3.3 +/- 1.6 for all, 3.5 +/- 1.5 for chronic, and 3.2 +/- 1.4 for ruptured, aneurysms (NS). Transdiaphragmatic repair was performed in 51/100 (51%) of all, 28/53 (53%) of chronic, and 17/33 (51%) of ruptured aneurysms (NS). Aortic cross-clamp time was 38 +/- 21 min for all, 39 +/- 24 min for chronic, and 38 +/- 17 min for ruptured, aneurysmal patients (NS). The amount of red cells washed and autotransfused was 2792 +/- 2239 ml in all, 3143 +/- 2531 ml in chronic, and 2074 +/- 1350 ml in ruptured, aneurysmal patients (P < 0.025). The amount of packed red cells required was 2181 +/- 1830 ml for all, 1736 +/- 1333 ml for chronic, and 2947 +/- 2395 ml for ruptured aneurysmal patients (P < 0.010). Thirty-day mortality was 9/100 (9%) for all, 3/53 (6%) for chronic, and 5/33 (15%) for ruptured aneurysmal patients (NS). Parapareses/plegias occurred in 9/100 (9%) of all, 6/53 (11%) of chronic, and 3/33 (9%) of ruptured, aneurysmal patients (NS). Stepwise regression analysis identified aortic cross-clamp time as a predictor of early mortality (P = 0.002) and parapareses and paraplegias (P = 0.001). Age (P = 0.001), extent of repair (P = 0.008) and preoperative hematocrit (P = 0.001) were predictors for homologous transfusion requirements. CONCLUSION: Emergency repair of ruptured descending thoracic and thoracoabdominal aortic aneurysms can be achieved with acceptable results.

Aortic Dissection↗
PubMed1996

Cardiac papillary fibroelastoma.

Papillary fibroelastomas are rare and benign heart tumors. We present two cases with these lesions. A young female patient with cerebral infarction was operated to resect the tumor on the mitral valve and the valve was successfully repaired. Another male patient had a history of bradycardia. On examination, coronary stenosis and a tumor in the left ventricle was found. Tumor excision combined with aorto-coronary artery bypass grafting was performed. Echocardiography proved to be highly effective to diagnose these tumors. Because of the potential cerebral and coronary embolization, these tumors should be excised. Surgical results are good.

Adult↗
PubMed1996

Pretransplant malignancy in candidates and posttransplant malignancy in recipients of cardiac transplantation.

BACKGROUND: Malignancy is generally considered a contraindication for cardiac transplantation, whereas secondary malignancy has been described under chronic immunosuppression. PATIENTS AND METHODS: We report here the frequency of malignancy encountered among the 495 patients evaluated at our cardiac transplant centre as well as the incidence and the course of post-transplant malignancy among 129 consecutive patients who underwent cardiac-transplantation, with a subsequent minimum follow-up of 6 months. RESULTS: A total of 10 out of 495 patients (2%) evaluated for heart transplantation presented with a history of previous malignancy: 3 of them underwent transplantation (2 survive, 1 died) whereas in the remaining 7 patients neoplasia was considered a contraindication for cardiac transplantation, and all 7 died (4 cardiac, 3 tumor-related deaths). Post-transplant malignancy was diagnosed in 10 of 129 patients (9%) 35 +/- 15 months after transplantation (6 skin cancers, 1 lymphoproliferative disease, 3 solid tumors). No significant association was found between post-transplant malignancy and primary prophylaxis with antithymocyte globulin (ATG) or murine antihuman T-cell monoclonal antibodies (OKT3). CONCLUSION: These results confirm that pre-transplant malignancy is not an absolute contraindication for cardiac transplantation and that post-transplant follow-up must include careful monitoring of post-transplant malignancy.

Adolescent↗
PubMed1996

Up-regulation of endothelin-B receptors in atherosclerotic human coronary arteries.

Both endothelin-A (ETA) and endothelin-B (ETB) receptors are known to be present in human coronary arteries. However, their absolute and relative amounts, functional roles, and the influence of pathology are uncertain. The goal of the present study was to characterize endothelin receptors mediating constriction in human coronary arteries and to assess the influence of cardiomyopathy (CMP) and coronary artery disease (CAD) on ET receptors in human tissue. For comparison, porcine coronary arteries were evaluated in parallel. Competition binding experiments using [125I]ET-1 and different selective and nonselective ETA- and ETB-receptor agonists or antagonists revealed similar relative densities (relative Bmax) of ETA and ETB receptors in coronary arteries from human cardiomyopathic hearts (83% ETA and 17% ETB; n = 5) and porcine hearts (78% ETA and 22% ETB; n = 5). In marked contrast, the relative Bmax of ETB receptors were significantly higher in coronary arteries from human atherosclerotic hearts (51% ETA and 49% ETB; n = 3). Total receptor density (Bmax; fmol/mg protein) was highest in porcine (385 +/- 29) arteries, followed by human CAD (253 +/- 41) and CMP (174 +/- 20) coronary arteries. The relative and absolute Bmax values for ETA and ETB receptors in coronary arteries from a donor heart were similar to those obtained in CMP hearts. There were no significant differences in affinity constants (KD) values for ET-1, ET-3, Sarafotoxin S6c (SRTX S6c), BQ-123, and bosentan (Ro 47-0203) between tissues. In human coronary arteries from CMP hearts, ET-induced constriction seemed to be solely mediated via ETA receptors. In contrast, in porcine coronary arteries 20% of the maximal effect mediated by ET-1 could be attributed to ETB receptors, in agreement with the binding data. The functional role of ETB receptors in CAD tissue could not be evaluated because of the occurrence of spontaneous phasic contractions. We conclude that ETB receptors are up-regulated in human atherosclerotic coronary arteries. Further studies are needed to determine the pathophysiological importance of these receptors.

Acetylcholine↗
PubMed1996

Sterno-laparotomy and extracorporeal circulation for liver transplantation after repeat-surgery for Budd-Chiari syndrome.

The surgical management of two patients undergoing living transplantation for Budd-Chiari syndrome is reported. Mesenteriocaval shunt had previously been performed in both cases, followed by transcaval liver resection and hepatoatrial anastomosis after 3 and 5 years, respectively. Liver transplantation was necessitated by deteriorating liver function with portal hypertension and recurrent bleeding. The successful operation was performed via sternolaparotomy. Atrioatrial anastomosis was constructed during cardiopulmonary bypass, considerably simplifying the technical procedure and dramatically reducing blood loss.

Adult↗
PubMed1996

Congenital coronary fistulas in children and adults: diagnosis, surgical technique and results.

Coronary artery fistula is a very rare congenital malformation with abnormal coronary-cameral communication that may involve any chamber and any or all coronary artery branches. We present our experience with 11 consecutive patients [mean age 16.6 years, ranging from 4 to 64 years]; 9 of them were treated surgically, spontaneous closure of the fistula was observed in one patient and one patient is still under observation. Fistulas originated from the right coronary artery in 4 patients and drained either into the right [n=3] or into the left system [n=1]. In 9 patients, the fistulas originated from the left coronary system and the fistulous communication developed with the right cardiac structures only. In 2 patients both coronary arteries were involved in the pathological drainage and 2 patients were demonstrated to have multiple drainage from the left coronary artery. Additional congenital cardiac malformations were found in 2 patients. Surgical closure of the fistula was successful in all operated patients [in one case treatment was possible without cardiopulmonary bypass]. Simple ligation of the fistula was performed in 1 patient, intracardiac closure of the fistula was combined with different reconstructive procedure in the other patients. Neither hospital mortality nor severe complications occurred. Mean follow-up interval was 39.4 months and all patients except one were in NYHA I. In presence of symptoms of congestive heart failure, significant left-to-right shunt and arrhythmias, elective closure of coronary fistula is generally accepted, whereas indication is more controversial in asymptomatic patients.

Adolescent↗
PubMed1996

[Analysis of early and late results of surgically treated Wolff-Parkinson-White syndrome].

The results of surgical procedures for termination of Wolff-Parkinson-White (WPW) Syndrom were assessed in 59 patients undergoing operation between January, 1980 and December, 1993. All cases of WPW were refractory to medical treatment and 14 of 58 patients had one or several syncopes, and 4 of them had to be reanimated. The surgical treatment of these patients was a dissection of an accessory atrioventricular pathway. 15 patients required additional heart operation. A total of 60 accessory pathways were diagnosed preoperatively, 64 were located intraoperatively. The reoperation rate was 3% (2 patients) due to persistent WPW. Incidence of total AV block after the operation was 7% (4 patients). In the late postoperative stage, 12 patients developed supraventricular tachycardias, but none of these cases required a surgical treatment. The actuarial survival rate after 10 years was 100% and after 14 years 96%. We conclude that surgical dissection of accessory pathways offers a good alternative in cases of unsuccessful catheter ablative procedure or in cases of additional heart operation.

Adolescent↗
PubMed1996

[32 years of Senning's correction for transposition of the great vessels].

Between 1962 and 1994 342 patients with transposition of the great arteries (TGA) were treated by atrial correction. Since 1992 the atrial switch operation is the treatment of choice for TGA. We reviewed our 32 year experience. Average age of the patients at operation was 69 months (7 days--8.5 years). 177/342 (52%) patients had a complex TGA: 74 patients with ventricular septal defect (VSD), 49 patients with pulmonary stenosis (PS) and 54 with both (VSD and PS). The 30 day mortality was for the whole series 15.7%. In the last 4 years 7.5%. The actuarial survival rate for all patients was 88% after 10 years and 82% after 20 years. For simple TGA 91% after 10 years and 83% after 20 years, for complex TGA 84% and 81%. The most important cause of death during our longterm observation were heart failure (19 patients) and sudden death (7 patients). Average follow-up for the whole group was 13.4 years. Most of the survivors are functionally symptom free (66% NYHA I) or they have slight symptoms (29% NYHA II). Only 5% were NYHA III or IV. Arterial switch operation has replaced the atrial correction for TGA. Nevertheless the longterm results after atrial correction remains encouraging. The main threat to the patients is the failure of the systemic ventricle.

Cardiac Surgical Procedures↗
PubMed1996

[Thrombosis-resistant heparin-coated diffusion membrane oxygenators: an experimental study].

In the present study the thromboresistance of heparin-coated diffusion membrane oxygenators (Jostra, M 30) combined with heparin-coated venous reservoirs, tubing sets and arterial filters was investigated in six bovine experiments (70 +/- 5 kg). The perfusion with reduced systemic heparin dose (100 IE/kg) body weight) was performed with activated clotting time over 180 seconds. The perfusion began with a blood flow of 31/min and was maintained during six hours. Clotting studies including blood platelet count, activated clotting time, fibrinogen (factor I), antithrombin III and fibrinopeptid A were performed before the operation and ten minutes, two hours and five and six hours after beginning of bypass. The venous and arterial saturation remained stable during the whole investigation. After ten minutes activated clotting time dropped from 619 +/- 114s to 203 +/- 15s after six hours (p < 0.05). The antithrombin III level changed significantly from 109 +/- 11% to 95 +/- 16%. Factor 1 and fibrinopeptid A changes were not significant: from 1.6 +/- 0.3 g/1 to 1.5 +/- 0.3 g/1, and 3.0 +/- 1.4 ng/mL to 3.5 +/- 1.2 ng/mL, accordingly. There were no mechanical defects and especially no plasma leakage. Slight sediments were found only in areas of stagnant blood flow. The investigated bypass circuit with reduced systemic heparinization seems therefore particularly appropriate for long-term perfusions.

Animals↗
PubMed1996

[Self-expanding endoluminal vascular prosthesis: experimental basis and in-vivo evaluation].

The present study investigates the physical properties and the in vivo application of in vivo of a self-expandable stent (Wallstent) with an incorporated sealant of microporous polyurethane. Measurements of diameter and length as a function axial load featured the data for the calculation for radial pressure. Porosity control was assessed in comparison to non gelatin-sealed knitted Dacron. 11 stents on a 11.5F catheter were inserted in the aorta of three minipigs and evaluated by pressure measurement and angiography. The coverage of the stent causes an increase of 0.05-0.1 bar of radial pressure. The graph received by calculations demonstrates the corresponding pressure for every given diameter of the stents. Porosity is similar to the Dacron graft. The patency-rate is 100%. Characteristics of this covered stents meet requirements of an endovascular prostheses. Exclusion of fistulas and small aneurysms seems to be possible.

Animals↗
PubMed1996

[Incidence, clinical aspects and therapy of late pericardial tamponade following heart surgery].

Late cardiac tamponade is a very severe condition that presents with subtle signs and symptoms within days or weeks after cardiac surgery. In a consecutive series of 3782 patients, 33 developed this complication, mostly due to overdosage of anticoagulants or to unsafe combination of 2 anticoagulation regimen. Diagnosis can be difficult and is best confirmed by echocardiography; in patients with primary uneventful recovery and sudden cardiocirculatory deterioration, intensive work-up should be performed to exclude or confirm the suspicion of late pericardial tamponade. The treatment of late pericardial tamponade should not be delayed and consists in subxyphoidal drainage. Re-sternotomy might be necessary to assume complete decompression of the heart in case of well-localized and posterior tamponade and/or organized pericardial fluid. Since this complication can happen in any patient transferred to peripheral hospital for postoperative recovery after cardiac surgery, we believe that this complication should be recognized very early and should be treated, in case of necessity, by general surgeons. Usually, no active bleeding is found at revision.

Adult↗
PubMed1996

[Latex covering and mechanical analysis of balloon expandable stents].

To the moment a few stents of metallic coils or meshes are available with a sealing coverage. In the present study balloon-expandable stents have been covered with a thin layer of natural rubber latex. The physical properties of these impervious stents were compared to the conventional stents. The expansion, the loss of expansion and the deformity during and after balloon inflation have been analyzed. In the pressure zone of 4-6 bar the mechanical characteristics of the impervious stents were similar to the conventional stents. The stents were expanded at 100% related on the balloon diameter used for expansion. Additional pressure of 1 bar was necessary to expand the impervious stents. At balloon pressure below 4 bar the stents tied the balloons in the midzone. The impervious stents, expanded at 6, 8 and 10mm, underwent a loss of expansion of 10% after withdrawal of the balloons. Their configuration was barrel-shaped (4% central enlargement) due to the latex rubber, constricting the wire meshes at both ends. These preliminary results are encouraging and allow further investigations.

Biomechanical Phenomena↗
PubMed1996

Low-dose cyclosporine treatment fails to prevent coronary luminal narrowing after heart transplantation.

BACKGROUND: Cyclosporine has been reported to induce endothelial dysfunction, arterial vasculitis, and accelerated atherosclerosis in experimental models. The purpose of the present study was to evaluate whether low-dose cyclosporine treatment started 1 year after heart transplantation reduces graft coronary artery narrowing compared with conventional cyclosporine doses. METHODS: One year after heart transplantation, 30 patients were randomly assigned to receive low-dose cyclosporine A (whole-blood polyclonal cyclosporine target trough levels 200 to 400 micrograms/L; group A; n = 15) or usual cyclosporine dosage (target levels 400 to 600 micrograms/L; group B; n = 15). Proximal and distal diameters of the left anterior descending, circumflex, and right coronary arteries were measured by quantitative coronary angiography at baseline (1 year after transplantation) and at 2 and 3 years after transplantation. RESULTS: One major cardiac event occurred in group A (retransplantation) and two in group B (sudden deaths). Moderate to severe allograft rejection (International Society for Heart and Lung Transplantation score 3A or higher) occurred in seven patients in group A and five in group B during the study period. Mean biopsy sample rejection score during the same period was increased in group A compared with that in group B (1.44 +/- 0.63 versus 1.05 +/- 0.59; p < 0.05). New angiographic evidence of vascular disease was observed in four patients of group A and in one patient of group B. Proximal coronary artery diameter was slightly, although not significantly, reduced in both groups at follow-up angiography. Distal segments showed a significant diameter reduction, which was greater in group A than in group B (-9.7% +/- 1.1% and -5.2% +/- 1.3%, respectively; p < 0.05). CONCLUSIONS: Cyclosporine dose reduction started 1 year after heart transplantation is ineffective in reducing coronary luminal narrowing and may be associated with an increased prevalence of cardiac allograft vasculopathy, especially in the distal coronary tree. Low-dose cyclosporine treatment may slightly enhance the risk of allograft rejection. Further investigations are needed to evaluate the effects of cyclosporine dose reduction started at an earlier time after heart transplantation.

Adult↗