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Biomedical subjects

M Turina

Publications and source records attributed to M Turina.

At least 307 records · Page 17Linked to original sources

[Surgery of ruptured aneurysms of the abdominal aorta and iliac arteries: mortality and early morbidity].

Two hundred patients with ruptured aneurysms of abdominal aorta and iliac artery were operated between 1979 and 1988. There were 179 males and 21 females with a mean age of 69 years (range 51 to 90 years). A total of 53/200 (27%) patients died in the hospital; of these 12/200 (6%) died intraoperatively. In following groups mortality was significantly higher: age greater than 70 years (37% vs 17%; p less than 0.01), preoperative shock (36% vs 14%; p less than 0.01), duration of symptoms greater than 12 hours (33% vs 17%; p less than 0.01), operative time greater than 240 min (53% vs 20%; p less than 0.01), intraoperative resuscitation (83% vs 21%; p less than 0.01), amount of volume greater than 4 liters (29% vs 12%; p less than 0.01) and intraperitoneal rupture (40% vs 24%; p less than 0.05). Location of rupture (suprarenal, infrarenal, iliac vessel), location of aortic clamping and the experience of the surgeon also influenced mortality but not significantly.

Aged↗

[Typical nosocomial infection with an unusual cause: Hafnia alvei. Report of 2 cases and literature review].

The route of infection and the course of two typical nosocomial infections are described in two patients infected with a rare gram-negative bacterium. Both patients underwent cardiovascular surgery. They were placed close to each other in the intensive care unit for several days and suffered from pneumonia and from wound infection respectively. In both patients bacterial culture grew Hafnia alvei. Successful antibiotic treatment was achieved with Netilmicin and Imipenem. Urinary tract, respiratory tract and wound infections are the most frequent nosocomial infections according to the literature. Risk factors are duration of stay in the intensive care unit, shock, poor general condition and advanced age.

Aged↗

[Long-term results of surgical coronary vessel intervention in patients with reduced left ventricular function].

From 1975 to 1980, 112 patients with an ejection fraction below 45% underwent coronary artery bypass grafting (CABG) in the Cardiovascular Surgery Unit, University Hospital Zürich. The mean age was 35 years and the mean ejection fraction 32% (21-44%). The vast majority of patients had severe symptoms (angina pectoris or congestive heart failure). Elective surgery was performed in 62 patients (55%) and emergent or urgent in 50 (45%). All were operated on in mild hypothermia (26-30 degrees C). An average of 2.9 bypasses per patient were performed; in 57, internal mammary artery bypass was carried out for revascularization of the left anterior descending branch. - Early postoperative mortality (within 30 days of operation) was 3.6%; all deaths were of cardiac origin. Perioperative myocardial infarction occurred in 7.5% of all patients. Cumulative survival was 83% at 5 years and 68% at 9 years. Mean mortality rate/year was 3.8% with a maximum of 6.5% in the first year after operation. The incidence of angina pectoris and congestive heart failure was significantly lower after revascularization. Cumulative survival was significantly enhanced in patients with complete revascularization (91% at 5 years vs 71% for incomplete revascularization). Early postoperative mortality was especially high in urgent and emergent cases, and was higher after revascularization with internal mammary artery bypass than with venous graft. Postoperative ejection fraction was assessed in 20 patients (12 with 2- or 3-vessel disease and 8 with left main coronary artery stenosis). Ejection fraction was significantly increased only in the patient group with left main coronary artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Long-term performance of mitral valve bioprosthesis].

Long-term clinical performance of mitral tissue valves was analyzed in a consecutive series of 250 patients (131 men, 118 women; mean age 51 years) over a 13-year period. Mean follow-up was 71 months (range 1-141 months). The total cumulative follow-up period was 1466 years. The late mortality was 2.0% per patient-year, whereas thromboembolism occurred in 1.4% per patient-year, prosthetic valve endocarditis in 1.0% per patient-year, periprosthetic leaks in 0.3% per patient-year and structural valve deterioration in 3.0% per patient-year. The rate of reoperation was 3.4% per patient-year. Actuarial analysis showed the following results (1 year/5 years/10 years): Survival rate: 97 +/- 1%/89 +/- 2%/82 +/- 5%; free of embolisms: 98 +/- 1%/96 +/- 1%/86 +/- 5%; free of endocarditis: 99 +/- 1%/95 +/- 2%/90 +/- 3%; free of valve deterioration: 99 +/- 1%/96 +/- 1%/60 +/- 8%; no reoperation: 98 +/- 1%/94 +/- 2%/57 +/- 8%; free of late complications: 92 +/- 2%/77 +/- 4%/41 +/- 10%. On the basis of our statistical evaluation the probabilities are that, 11 years after implantation of a mitral bioprosthesis: (a) only 35% of patients are free of late complications (including thromboembolisms, prosthetic valve endocarditis, structural valve deterioration and death); (b) and only 50% of patients have not needed reoperation.

Actuarial Analysis↗

[Injuries of the large brain-feeding arteries].

Among 2923 severely injured patients in the period 1980-1988, 17 had injuries or large supraaortic arteries. The incidence was 0.58%, with an overall mortality of 53%. In 75% of survivors there was a persistent neurological deficit. We treated 5 penetrating (A. carotis 4, A. vertebralis 1) and 12 nonpenetrating (A. carotis 11, A. vertebralis 1) injuries. In all penetrating carotid injuries (4) repair was performed on admission and mortality was 50%; 1 of 2 survivors has postoperative hemiparesis. Localization of nonpenetrating carotid injuries (11) was intrathoracic (2), in the neck (7) and intracranial (2). Main complication of nonpenetrating extracranial carotid injuries is neurological deficit (7/9) due to thrombosis (3) or stenosis (4) with embolism (2). Surgery was performed in 3 cases comprising pseudoaneurysm in 2 and concomitant aortic rupture in 1. Mortality was 44%, and 80% of survivors had persistent neurological deficits. Extracranial carotid injuries (n = 13) carried a mortality rate of 83% in occluded and 29% in nonoccluded vessels (p less than 0.05). Location of carotid injury in the neck (n = 11) carried a mortality of 55%, and intracranial (n = 2) of 100% respectively. Duplex-Doppler scanning of carotid arteries is a safe, noninvasive method which is essential in blunt carotid artery trauma. Prognosis is dependent upon the size of cerebral infarction. Once neurologic deficit has been established for more than 24 hours, reconstruction of the artery should be postponed and performed only for complications (pseudoaneurysm or embolization). Clamping of arteries without hypothermic circulatory arrest or shunt should be avoided. The danger of rupture in dissection and pseudoaneurysm is slight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Permeability pulmonary edema in pheochromocytoma].

We describe two patients with pheochromocytoma who developed pulmonary edema of rapid onset. The edema occurred spontaneously in the first case and during surgery for the tumor in the second patient. Since left ventricular function was normal in both patients and the protein content of the edema fluid was elevated in one patient, the conditions involved were permeability edemas.

Adrenal Gland Neoplasms↗

Liver transplantation with atrioatrial anastomosis for Budd-Chiari syndrome.

We report the case of a young woman with Budd-Chiari syndrome in whom mesentericoval shunt was first performed, followed by transcaval liver resection and hepatoatrial anatomosis 3 years later. Liver transplantation became necessary 5 years later because of deterioarating liver function with portal hypertension and bleeding. Successful transplantation was performed with atrioatrial anastomosis with help of cardiopulmonary bypass, simplifying considerably the technical procedure and reducing dramatically blood loss.

Adult↗

Futility of pericardiectomy for postirradiation constrictive pericarditis?

Two patients underwent pericardiectomy for postirradiation constrictive pericarditis. Both had received radiotherapy (more than 6,000 rads) for treatment of Hodgkin's disease 17 (patient 2) and 20 years (patient 1) earlier. At the time of operation, the patients were in New York Heart Association functional class III-IV or IV. Preoperative catheterization showed the following pressures for patients 1 and 2, respectively: right atrial, 30 and 14 mm Hg; right ventricular end-diastolic, 28 and 14 mm Hg; wedge, 29 and 13 mm Hg; and left ventricular end-diastolic, 27 and 14 mm Hg. Complete epicardiectomy and pericardiectomy was attempted in both patients. However, hospital mortality was 100%; patient 1 died of multiorgan failure after six days, and patient 2 died of biventricular failure after 3 months. A review of the literature revealed 44 cases of pericardiectomy for postirradiation constrictive pericarditis and a late survival rate of less than 50%. The poor results in these patients compared with patients having pericardiectomy for other reasons seem to be due mainly to the various kinds of radiation-induced damage to the heart as a whole, including untimely coronary artery disease, myocardial fibrosis, atrioventricular conduction disturbances, and valve dysfunction, with the result that complete relief by epicardiectomy and pericardiectomy may not be technically feasible.

Adult↗

Noninvasive versus invasive assessment of cardiac output after cardiac surgery: clinical validation.

The accuracy of noninvasive cardiac output (CO) measurement techniques, such as electrical bioimpedance (BIO), suprasternal continuous-wave Doppler (CWD), pulsed-wave Doppler (PWD), and transesophageal continuous-wave Doppler (TED) ultrasound has been variably judged in recent years. In addition, clinical comparisons are hampered by the fact that there is no generally accepted gold standard in CO measurement. After coronary artery bypass surgery in 25 patients, CO was simultaneously determined by invasive standard techniques (thermodilution [TD] and Fick methods) plus BIO, CWD, PWD, and TED. There was an excellent agreement found between TD and the Fick method (COF = 0.13 + 1.01.COTD; r = 0.96; n = 99). Thermodilution was thus chosen to be the reference method. Bioimpedance underestimated COTD (COBIO = 0.47 + 0.60.COTD; r = 0.78; n = 111). Allowing physiological ejection times only led to an improved agreement between BIO and TD (COBIO = 0.05 + 0.69.COTD; r = 0.82; n = 79), but BIO still significantly underestimated COTD (P less than 0.0005). Using physiologic ejection times during COCWD determination reduced the scatter of data as compared with TD; however, CWD still considerably overestimated COTD, when COCWD computation was based on the echocardiographic aortic diameter (ECHO) (COCWD ECHO = 0.79 + 1.40.COTD; r = 0.84; n = 52). With the surgical aortic diameter (SURG), the agreement improved (COCWD SURG = 0.75 + 1.16.COTD; r = 0.89; n = 44), but overestimation of COTD remained significant (P less than 0.05). Irrespective of the aortic diameter, COPWD values showed a considerable scatter of data compared with COTD (COPWD ECHO = 1.26 + 0.60.COTD; r = 0.62; n = 64 and COPWD SURG = 1.42 + 0.41.COTD; r = 0.47; n = 61). Correlation of absolute COTED values to thermodilution depended on the method used for calibration. All investigated noninvasive CO measurement techniques unreliably measured relative CO changes. Despite its invasiveness, TD remains the method of choice for accurate CO determination in adult patients following cardiac surgery.

Adult↗

Superior hemodynamics in left heart bypass without systemic heparinization.

Open-chest left heart bypass was performed in 10 canine experiments (30 +/- 9 kg) by a servo controlled roller pump for 6 h at a pump flow of 50 ml/min per kg bodyweight. The surfaces of the tubing sets were either standard (with systemic heparinization) or with end-point attached heparin (no systemic heparin). Besides continuous monitoring of hemodynamics, a standard battery of blood samples was taken before bypass, after 10 min and every hour thereafter. There is no evidence of increased fibrin production in the group with end-point attached heparin surfaces perfused without systemic heparinization. Superior hemodynamics in left heart bypass performed without systemic heparinization appear to be due to improved hemostasis, reduced blood loss and therefore reduced transfusion requirements. Left heart bypass with heparin-coated equipment has been successfully used for resection of a thoracoabdominal aneurysm in six patients.

Animals↗

Reduced blood loss and transfusion requirements with low systemic heparinization: preliminary clinical results in coronary artery revascularization.

In coronary artery revascularization, low systemic heparinization was compared to full systemic heparinization during perfusion with heparin surface-coated cardiopulmonary bypass equipment. Twelve patients were randomly assigned to two groups and perfused with low [activated clotting time (ACT) greater than 180 s] or full (ACT greater than 480 s) systemic heparinization. A standard battery of blood samples was taken before the procedure, after heparinization, and at regular intervals during and after cardiopulmonary bypass. No differences were seen between the two groups in regard to age, body surface area, preoperative hematocrit, duration of bypass, bypass hypothermia, cross-clamp time, and number of bypasses per patient. However, there were more internal thoracic artery (ITA) grafts in the group with low systemic heparinization (1.5 +/- 0.8 ITA grafts per patient versus 0.8 +/- 0.4 ITA grafts per patient with full heparinization; p less than 0.05). The oxygenator gradient at the end of perfusion (before weaning) was 107 +/- 40 mmHg for low versus 110 +/- 10 mmHg for full heparinization (difference not significant). The total amount of heparin used was 7200 +/- 1030 IU for low versus 51400 +/- 9700 IU for full (p less than 0.05). Postoperative hematocrit was 35.0 +/- 2.0% for low versus 24.7 +/- 2.7% for full (p less than 0.05). Total chest tube drainage was 428 +/- 153 ml/m2 for low versus 935 +/- 414 ml/m2 for full (p less than 0.05). Homologous transfusions of blood products were necessary in 3/6 patients for low versus 6/6 patients for full (p less than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗

Performance characteristics of centrifugal pumps with heparin surface coating.

Heparin surface coating is one approach to improve the biocompatibility of existing blood pumps used for mechanical circulatory support. Experimental evaluation of centrifugal pumps with heparin surface coating was performed during open chest left heart bypass (3.7 L/min over 6 hours) in two series of bovine experiments. Eight calves (74 +/- 4 kg) were perfused either by heparin surface coated equipment without systemic heparinization or uncoated equipment with systemic heparinization (300 I. U,/kg bodyweight; ACT greater than 400 s). A standard battery of analyses was performed before and at regular intervals after onset of perfusion. At the end of perfusion all pump-heads were gently rinsed. There were no macroscopic clots for both groups whereas macroscopic clots were observed in uncoated tubings introduced for control in the group perfused without systemic heparinization. The hemodynamics were significantly better in the group perfused without systemic heparinization and maintained functional coagulation system. Clinical application of heparin surface coated equipment during resection of thoraco-abdominal aortic aneurysms is showing promising results in 12 patients.

Animals↗

Different mobilization of calcium in endothelin-1-induced contractions in human arteries and veins: effects of calcium antagonists.

We studied the role of extra- and intracellular Ca2+ in endothelin-1-induced contractions of the isolated human internal mammary artery and vein. Veins were more sensitive to the peptide than arteries (concentration shift:3.2-fold; n = 4-10, p less than 0.05). The Ca2+ antagonists darodipine, verapamil, and diltiazem (10(-7)-10(-6) M) did not prevent the response to endothelin-1 in both vessels. In contrast, darodipine (10(-8)-10(-6) M), added after the contraction had developed, partially reversed the response in the artery (26 +/- 7%) and particularly in the vein (67 +/- 5%; n = 4, p less than 0.005 compared to the artery). Removal of extracellular Ca2+ reduced the contractions to endothelin-1 (10(-8) M) in the artery (control: 89 +/- 4% of 100 mM KCl; Ca2(+)-free: 68 +/- 4% n = 4-6, p less than 0.01), but not in the vein except at low concentrations (10(-9) M) of the peptide. After removal of intracellular Ca2+ with caffeine in the artery, endothelin-1 still evoked a contraction (17 +/- 3%, n = 3; p less than 0.005 vs. control), while in the vein the response was abolished. Thus, mobilization of Ca2+ during endothelin-1-induced contractions differs in the human internal mammary artery and vein. In the artery, the contraction depends on extracellular Ca2+, intracellular caffeine-sensitive Ca2+ stores, and a caffeine-insensitive component, while in veins, mobilization of intracellular Ca2+ is most important. Ca2+ antagonists do not prevent, but partially reverse, endothelin-1-induced contractions indicating that voltage-operated Ca2+ channels do not initiate but contribute to the maintenance of the response.

Caffeine↗

Threshold concentrations of endothelin-1 potentiate contractions to norepinephrine and serotonin in human arteries. A new mechanism of vasospasm?

Endothelin-1 is an endothelium-derived vasoconstrictor peptide. Its circulating levels are below those known to evoke direct vascular effects. To study whether low concentrations of endothelin-1 potentiate the effects of other vasoconstrictor hormones, we suspended isolated human internal mammary and left anterior descending coronary artery rings in organ chambers for isometric tension recording. In mammary artery rings, the contractions to norepinephrine (3 x 10(-8) M) were potentiated by threshold (3 x 10(-10) M) and low concentrations (10(-9) M) of endothelin-1 (96 +/- 35% and 149 +/- 58% increase from control; p less than 0.01 and 0.001; n = 6). The inhibitor of endothelial nitric oxide formation L-NG-monomethyl arginine did not affect the potentiating effects of the peptide. The calcium antagonist darodipine (10(-7) M) prevented the potentiation of the response to norepinephrine evoked by endothelin-1. Similarly, contractions to serotonin (10(-7) or 3 x 10(-8) M) were amplified by endothelin-1 (3 x 10(-10) M) in the mammary (30 +/- 9%) and in the coronary arteries (59 +/- 25%). Endothelin-1 (10(-9) M) further potentiated the response (57 +/- 23% in mammary and 87 +/- 26% in coronary arteries; p less than 0.05; n = 7 and 3). The sensitivity of mammary arteries to calcium chloride was markedly enhanced in the presence of endothelin-1 (3 x 10(-10) M; concentration shift, eightfold; p less than 0.01; n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Arteries↗

Interaction between endothelin-1 and endothelium-derived relaxing factor in human arteries and veins.

Endothelin-1 is a 21-amino acid endothelial vasoconstrictor peptide that may be the physiological antagonist of endothelium-derived relaxing factor (EDRF). Endothelin-1 (10(-11)-3 x 10(-7) M) evoked potent contractions of isolated internal mammary arteries, internal mammary veins, and saphenous veins, which were enhanced in internal mammary veins as compared with internal mammary arteries (concentration shift, 6.3-fold; p less than 0.05) but not in the saphenous veins. Endothelial removal augmented the response to the peptide (at 3 x 10(-7) M) in internal mammary arteries (p less than 0.05) but not in veins. In the artery, EDRF released by acetylcholine or bradykinin reversed endothelin-1-induced contractions; in saphenous veins, both agonists were much less effective compared with the artery and veins contracted with norepinephrine (p less than 0.005-0.01). This inhibition of endothelium-dependent relaxations in veins occurred at half-maximal contractions but was most prominent at maximal contractions to the peptide. Nitric oxide similarly inhibited contractions to endothelin-1 and norepinephrine in internal mammary arteries, whereas in veins that were contracted with endothelin-1 but not with norepinephrine, the relaxations were blunted (p less than 0.005). The nitric oxide donor SIN-1 and sodium nitroprusside induced complete relaxations of internal mammary arteries but were less effective in veins contracted with endothelin-1 (p less than 0.005). Thus, in normal human arteries, EDRF inhibits endothelin-1-induced contractions, whereas the peptide specifically attenuates the effects of EDRF and nitrovasodilators in veins. This may be important in pathological conditions associated with increased levels of endothelin-1 and in veins used as coronary bypass grafts.

Acetylcholine↗