Search PubMed⌕ Search

Biomedical subjects

M I Turina

Publications and source records attributed to M I Turina.

At least 127 records · Page 7Linked to original sources
PubMed1994

Treatment of acute pulmonary hypertension with inhaled nitric oxide.

We examined the effectiveness of inhaled nitric oxide (NO) as a selective pulmonary vasodilator in acute pulmonary hypertension in an in vivo canine model with fixed cardiac output. In 5 dogs, total right heart bypass was instituted, and pulmonary hypertension was induced by infusion of the thromboxane analogue U-46619. During U-46619 infusion, NO was administered at 10 and 40 ppm for 5 minutes followed by breathing of the oxygen mixture without NO. Pump flow was held constant during the experiment. Infusion of the thromboxane analogue resulted in an increase in pulmonary vascular resistance and systemic vascular resistance from 147 +/- 83 to 740 +/- 126 dyne.s.cm-5 and from 1,720 +/- 113 to 2,407 +/- 232 dyne.s.cm-5, respectively. During inhalation of 10 ppm NO, pulmonary vascular resistance significantly decreased to 613 +/- 55 dyne.s.cm-5 (p < 0.05) and further decreased to 527 +/- 163 dyne.s.cm-5 with 40 ppm NO inhalation (p < 0.05). Systemic vascular resistance did not change during NO treatment (2,300 +/- 70 dyne.s.cm-5 during 40 ppm NO). There was no increase in intrapulmonary shunting or methemoglobin levels during NO inhalation. In this setting, with a constant cardiac output throughout the experiment, NO acted as a selective pulmonary vasodilator without altering systemic vascular resistance. However, induced pulmonary vasoconstriction was only partially reversed by NO inhalation.

Acute Disease↗
PubMed1994

Superior late patency of small-diameter Dacron grafts seeded with omental microvascular cells: an experimental study.

The purpose of the study was to investigate the effect of omental microvascular cell seeding on the patency of small-diameter Dacron prostheses usable for coronary artery bypass grafting. In a canine carotid artery model, each dog (n = 64) received one seeded and one similar nonseeded Dacron prosthesis (internal diameter = 4 or 6 mm). Enzymatically harvested omental microvascular cells (omentum = 27.6 +/- 5.9 g [+/- the standard deviation]; range, 17 to 50 g) were seeded prior to implantation. The seeding density was 1.91 +/- 0.26 [+/- the standard error] x 10(6) cells/cm2 of graft surface. Dipyridamole (75 mg/d) and acetylsalicylic acid (325 mg/d) were administered orally for 4 weeks postoperatively. The prostheses were explanted between 2 and 52 weeks after placement. The results were assessed by angiography; light, scanning electron, and transmission electron microscopy; and morphometry. The seeded grafts developed a uniform luminal monolayer of endothelial cells with minimal platelet or cellular deposition. These grafts also had a significantly higher overall patency rate and significantly larger thrombus-free surface areas than the nonseeded grafts. The overall actuarial patency rates at 1 week, 5, 12, 26, and 52 weeks were 100%, 98%, 93%, 93%, and 93%, respectively, for seeded Dacron grafts and 100%, 91%, 61%, 54%, and 18%, respectively, for nonseeded grafts. The patency rates of Dacron grafts usable for coronary artery bypass grafting are significantly improved by seeding with omental microvascular cells in a canine model.

Actuarial Analysis↗
PubMed1994

Aortic homograft and mitral valve repair in a patient with Werner's syndrome.

We report the case of a 66-year-old man suffering from Werner's syndrome (adult progeria); he presented with several cardiac disorders, including coronary artery disease, aortic stenosis, and mitral regurgitation, mainly due to calcific deposits in the mitral annulus and the aortic cusps. Treatment consisted of mitral repair, homograft replacement of the aortic valve, and coronary artery bypass grafting. Avoidance of prosthetic material because of chronic infectious skin ulcers constituted the main goal of the operation.

Aged↗
PubMed1994

Risk and benefit of low systemic heparinization during open heart operations.

Heparin surface-coated perfusion equipment with improved thromboresistance was evaluated in 104 consecutive patients undergoing open heart operation in a prospective, randomized trial with low versus full systemic heparinization. Surgical procedures included coronary artery revascularization in 47 of 54 (87%) for low versus 44 of 50 patients (88%; not significant [NS]) for full, valve repair/replacement in 8 of 54 (15%) for low versus 5 of 50 patients (10%; NS) for full, left ventricular aneurysm repair in 1 of 54 (2%) for low versus 2 of 50 patients (4%; NS) for full, and other in 3 of 54 (6%) for low versus 3 of 50 patients (6%; NS) for full. Cross-clamp time was 39.2 +/- 10.7 minutes for low versus 39.5 +/- 10.5 minutes for full (NS). Cardiopulmonary bypass time was 68.6 +/- 20.1 minutes for low versus 69.3 +/- 16.6 minutes for full (NS). Lowest activated coagulation time during perfusion was 255 +/- 75 seconds for low versus 537 +/- 205 seconds for full (p < 0.0005). In the low group, the target activated coagulation time of more than 180 seconds was not reached during perfusion in 4 of 54 patients (7%), the lowest value being 164 seconds. No oxygenator failure occurred. Hospital mortality was 0 of 54 (0%) for low versus 1 of 50 patients (2%) for full (NS). Bleeding required surgical revision in 0 of 54 (0%) for low versus 4 of 50 patients (8%) for full (p = 0.05). Drainage (24 hours) was 790 +/- 393 mL for low versus 1,039 +/- 732 mL for full (p < 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1994

Surgical revascularization in acute myocardial infarction.

To determine the potential benefit of myocardial revascularizations in acute myocardial infarction we analyzed a consecutive series of 641/3397 patients with stable or unstable angina in Canadian Heart Association Class IV divided into five groups: A) unstable angina (ECG S-T modifications), B) evolving infarction (new Q-wave, CK more than 3 times normal), C) mechanical complications (ventricular septal defect (VSD), wall rupture, acute mitral regurgitation), D) coronary artery occlusion (crashed percutaneous transluminal coronary angioplasty (PTCA)), and E) stable angina class IV (control group). The mean follow-up was 72 +/- 33 months (range 24-144 months). Of the 641 patients 362 were unstable (A), 22 had evolving infarction (B), 20 suffered from mechanical complications (C), 48 had acute coronary artery occlusion (D), and 189 were in the control group (E). There was no difference for left ventricular (LV) ejection fraction before surgery (P < 0.05 = * as compared to control (E)), however cardiogenic shock was present before surgery in 13/362 (4%) for unstable angina, 5/22 (23%) for evolving infarction, 6/20 (30%) for mechanical complications, 4/48 (8%) for acute occlusion, and none of the controls. The number of bypasses was 3.8 +/- 1.3* for unstable angina, 3.6 +/- 1.3 for evolving infarction, 2.3 +/- 1.2* for mechanical complications, 2.0 +/- 1.2* for acute occlusion, and 3.4 +/- 1.5 for control. Intra-aortic balloon pumping was necessary in 26/362 (7%) for unstable angina, 5/22 (23%*) for evolving infarction, 7/20 (35%*) for mechanical complications, 7/48 (15%*) for acute occlusions, and 5/189 (3%) of the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Assisted circulation without systemic heparinization.

The need for improvements in materials and equipment for extracorporeal circulation has been obvious for years. Among the surfaces with biologically active compounds, those with heparin binding have been found sufficiently thromboresistant and particularly suitable for different types of artificial perfusion. Partial left heart bypass (LHBP) was performed in 10 anesthetized, acutely instrumented, and open-chested mongrel dogs (weight 23 to 50 kg) with a servo-controlled roller pump. The pump flow was maintained at 50 mL/kg/min for 6 hours. Heparin surface-coated equipment was used without additional heparin. For LHBP with a standard circuit, the total amount of heparin during the study period was (mean +/- SD) 487 +/- 124 IU/kg. The right atrial, pulmonary artery, and left ventricular end-diastolic pressures, cardiac output, left ventricular output, right and left ventricular stroke work, pulmonary gas exchange, and acid-base balance changed similarly with both systems. Blood loss (204 +/- 78 v 1,240 +/- 586 mL, P < 0.0005), volume substitution requirements (647 +/- 48 v 1,860 +/- 764 mL, P < 0.0025), and oxygen extraction ratio (mean 25.4 to 32.0 v 25.4 to 56.4%, P < 0.025) were significantly lower, and mean aortic pressure (mean 65 to 69 v 62 to 38 mmHg, P < 0.025) and hemoglobin concentration (mean 9.1 to 8.1 v 9.4 to 3.9 g/dL, P < 0.05) were significantly higher during 6 hours of LHBP without systemic heparinization. Low but stable oxygen delivery was provided with heparin-coated LHBP, whereas it showed a descending trend (mean 14.0 to 10.8 v 13.4 to 5.5 mL/kg/min, P < 0.1) with the standard circuit.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Early and late results after correction for double-outlet right ventricle: uni- and multivariate analysis of risk factors.

Between April 68 and May 91, 59 patients underwent total correction for double-outlet right ventricle. The mean age was 59.2 +/- 7.8 months. The hospital mortality rate was 27%; it was 41% before 1980 and 13% thereafter. Low cardiac output failure was the leading cause of early death. Myocardial protection without cardioplegia and long cardiopulmonary bypass time were significant predictors of hospital mortality in univariate as well as in multivariate analysis. The late death rate was 7%. The actuarial survival rate was 67% (CL 55-80%) after 10 and 20 years. The reoperation rate was 42%, a loose VSD patch constituted the main indication (23%). The actuarial freedom from reoperation rate was 51% (CL 33%-69%) after 10 years and 31% (12%-50%) after 20 years. The mean follow-up time was 8.4 +/- 0.9 years (2 to 20 years). Seventy-five percent of all postoperative survivors are in NYHA functional class I and left ventricular ejection fraction is normal in 82%.

Adolescent↗
PubMed1994

Anomalous origin of the right coronary artery from the pulmonary artery.

Isolated anomalous origin of the right coronary artery (RCA) is a very rare congenital malformation. The case of a 15-month-old boy with anomalous origin of the RCA from the pulmonary artery is presented. The RCA was reimplanted into the aorta. The anatomical correction was uneventful and its success demonstrates that diagnosis and surgical correction are possible at a very young age.

Aorta↗
PubMed1994

Dissection of the descending thoracic aorta extending into the ascending aorta. A therapeutic challenge.

Proper management of dissections of the descending thoracic aorta with intimal disruption close to the left subclavian artery and retrograde extension of the dissection into the aortic arch or the ascending aorta is controversial, because the standard approach for ascending aortic aneurysms is surgical repair, which is difficult to achieve through a median sternotomy if the predominant aortic lesion is located in its descending part. Sixteen patients with descending thoracic aortic dissection, intimal disruption close to the subclavian artery, and extension of the dissection into the aortic arch or the ascending aorta are described here: Eleven patients underwent surgical repair including 9 emergency (82%) and 2 elective (18%) procedures. Retrograde aortic dissection included the aortic arch in 11 of 11 patients (100%) and the ascending aorta in 7 of 11 (63%). Pericardial effusion was present in 1 of 11 patients (9%) and mild aortic regurgitation was found in 1 of 11 (9%). Repair of the ascending aorta and arch with transaortic closure of the entrance tear in the descending thoracic aorta was performed in 4 of 11 patients (36%) via a median sternotomy. In 6 of 11 patients (55%) a lateral thoracotomy was used for repair of the descending thoracic aorta and closure of the entrance tear. Hospital mortality occurred in 1 of 11 patients (9%) and there was 1 late death. Paraplegia occurred in 1 of 11 patients (9%). Five patients with descending thoracic aortic dissection, intimal disruption close to the subclavian artery, and extension into the ascending aorta but without ascending aortic aneurysm (diameter 4.2 +/- 0.2 cm), pericardial effusion, or aortic incompetence were treated medically without early mortality. These results are compared with those achieved in 120 patients operated on during the same period for type A (89/120) and type B (31/120) aortic dissections. Considering the technical difficulties of simultaneous repair of dissections of the ascending and the descending thoracic aorta, we recommend that descending thoracic aortic dissection extending into the arch or the ascending aorta be managed in accordance with the site of the predominant lesion. Replacement of the arch with a varying portion of ascending aorta via a median sternotomy is recommended in patients with enlarged aortic diameter, pericardial effusion, and/or aortic insufficiency. Predominantly distal dissections with dilated descending thoracic aorta and/or distal complications are best approached via a lateral thoracotomy.

Adolescent↗
PubMed1993

[Bullet embolism. Case report and literature review].

Migratory intravascular bullets may produce confusing clinical pictures in patients with gunshot wounds. We report on a patient in whom the missile entered the right chest at the fourth intercostal space in the anterior axillary line. The bullet was finally found in the abdominal aorta. The penetration site remained unclear but was probably the heart. After repair of the chest wall the bullet was successfully removed from the aortic bifurcation.

Adult↗
PubMed1993

[Hemodynamic effects of the implantation of an intracaval oxygenator].

Treatment of severe respiratory failure by extracorporeal membrane oxygenation (ECMO) is complex. However, there is now an intravascular gas exchanger (IVOX) available that provides extrapulmonary gas transfer without requiring an extracorporeal blood path. The present study was performed to determine the hemodynamic effects resulting from the intracaval placement of the intravascular device. A bovine model (n = 6; body-weight = 72 +/- 5 kg) was selected for temporary lung support with the intravascular device. The latter was placed in the caval axis under fluoroscopic control after full instrumentation of the animal for hemodynamic measurements including a pulmonary artery catheter for determination of cardiac output by thermodilution and continuous readout of mixed venous oxygen saturation. All measurements were taken after a stabilization period of 15 min. The heart rate moved from 65 +/- 8 before to 72 +/- 10 after implantation and 68 +/- 9 after onset of intravascular gas exchange (NS). Right atrial pressure was 13 +/- 3 mm Hg before, 12 +/- 3 mm Hg after implantation and 10 +/- 3 mm Hg after onset (NS) whereas femoral venous pressure moved from 14 +/- 3 mm Hg to 17 +/- 4 mm Hg (p < 0.05) and remained at 17 +/- 4 mm Hg after onset. Cardiac output was 5.3 +/- 0.7 l/min before, 5.4 +/- 0.7 l/min after implantation and 5.3 +/- 1.1 l/min after onset (NS) while mixed venous oxygen saturation dropped from 60 +/- 7% to 54 +/- 11% and moved to 57 +/- 11 after onset of the device (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Sternal cleft associated with vascular anomalies and micrognathia.

Sternal defects combined with craniofacial vascular defects are rare. We report on a 45-year-old woman with a sternal cleft associated with craniofacial and brain hemangiomata, an aneurysm of the aortic arch, anomalous origin of the coronary arteries, a left superior vena cava, micrognathia, supraumbilical midline raphe, and a cervical cyst. The surgical procedure consisted of the resection and replacement of the aortic arch and the innominate artery with reimplantation of the left carotid artery into the graft under circulatory arrest and deep hypothermia. The presence of sternal cleft is an indication for the search for other asymptomatic internal vascular anomalies.

Abnormalities, Multiple↗
PubMed1993

Improved distal circulatory support for repair of descending thoracic aortic aneurysms.

Bleeding is a well-known problem when cardiopulmonary bypass with full systemic heparinization is used for distal support during aortic cross-clamping. The recent advent of heparin-coated cardiopulmonary bypass equipment prompted our review of 91 consecutive patients who underwent repair of descending thoracic and thoracoabdominal aortic aneurysms. Two different surgical techniques were used: 42 of 91 patients had simple aortic cross-clamping and rapid reanastomosis, whereas 49 of 91 had distal support using all heparin-coated perfusion equipment with low systemic heparinization (100 IU/kg body weight; activated coagulation time > 180 seconds). Baseline parameters, location (thoracoabdominal: 28/91; 31%), and type of aneurysm (ruptured: 14/91; 15%) were similar in both groups. Cross-clamp time was 37 +/- 22 minutes for support versus 29 +/- 13 minutes for simple clamping (p < 0.05). There were fewer revisions due to bleeding for support (1/49 patients; 2%) versus simple (4/42; 10%; p < 0.05) and fewer patients with impaired renal function requiring temporary hemofiltration for support (4/49 patients; 8%) versus simple (6/42; 14%). Hospital mortality was lower for support (5/49; 10%) versus simple (8/42; 19%). Transfusion requirements during operation were 3,732 +/- 3,458 mL for simple versus 3,392 +/- 2,058 mL for support (not significant). Chest tube drainage totaled 982 +/- 1,102 mL for simple versus 720 +/- 618 mL for support (not significant). The total volume requirements were 8,156 +/- 4,753 mL for simple versus 7,495 +/- 3,342 mL for support (not significant) during operation and 4,416 +/- 2,422 mL for simple versus 3,380 +/- 1,432 mL for support (p < 0.025) during the 24 hours after operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Reoperations after operation on the thoracic aorta: etiology, surgical techniques, and prevention.

Recurrent aortic aneurysms, persistent or new dissection, new onset of valvular and coronary artery disease, graft infection, and prosthetic endocarditis are not rare after thoracic aortic operations; they can be difficult to diagnose and represent a formidable surgical challenge. Between 1977 and 1991, 876 operations were performed on the thoracic aorta in our institution: 340 in dissections, 299 in true aneurysms, 150 for aortic remodeling and external wall support during aortic valve replacement, and 87 for miscellaneous causes. During the same period, there were 193 additional reoperations. Vascular reoperations on abdominal aorta and peripheral arteries accounted for 73 cases and are not further discussed in this study. The reasons for reoperation (n = 130) in 120 patients were: failure of biologic valves (n = 23); aneurysm recurrence in a proximal or distal aortic segment (n = 21); pseudoaneurysm formation at suture lines (n = 13); new dissection or dilatation involving ascending aorta (n = 11), aortic arch (n = 13), and descending aorta (n = 10); aneurysm after aortic remodeling (n = 13); new onset of valvular disease (n = 5); and new onset of coronary disease (n = 5). Infected aortic graft and prosthetic endocarditis accounted for 10 reoperations, and a planned two-staged procedure was performed in 6 patients. Omitting the failed biologic valves, reoperations were performed on the aortic segment previously operated on in 69.3% of the cases and on other thoracic segments in 30.7%. Overall hospital mortality rate after reoperation was 5.8%. A significant decrease in operative mortality was observed in the most recent period (3.0% between 1989 and 1991). Reoperations are technically demanding, and some of them are preventable; therefore (1) graft inclusion technique should be abandoned in ascending aortic operation due to formation of false aneurysms; (2) in patients with Marfan syndrome, complete repair of the diseased aorta should be attempted during the initial operation; (3) aortic arch dissection should be repaired definitively during the first operation in low-risk patients; (4) biological valves should be avoided in aneurysm operations; and (5) homograft replacement is the treatment of choice in prosthetic endocarditis or in infected composite graft after an aortic valve or ascending aortic operation.

Actuarial Analysis↗
PubMed1993

Cardiotomy suction versus red cell spinning during repair of descending thoracic aortic aneurysms.

Two consecutive series of patients undergoing repair of descending thoracic and thoracoabdominal aortic aneurysms with partial cardiopulmonary bypass and low systemic heparinization (activated coagulation time: ACT greater than 180 sec) for proximal unloading and distal protection were analyzed. During the surgical procedures, thoracic shed blood was recovered either with a red cell spinning autotransfusion device (n=10) or two pump suckers and Duraflo II heparin surface coated cardiotomy reservoirs (n=10). There were 5/10 acute lesions and 1/10 ruptures for the autotransfusion group versus 5/10 acute lesions and 2/10 ruptures for the cardiotomy group (NS). Extension of aortic resection (range 1-8) was 3.6+/-1.2 for autotransfusion versus 3.5+/-1.4 for cardiotomy suction (NS). Mean number of reimplanted patches for intercostal and visceral reperfusion was 0.3+/-0.6 for autotransfusion versus 0.6+/-1.0 for cardiotomy (NS). Perfusion time was 41+/-17 min for autotransfusion versus 60+/-19 min for cardiotomy (p less than 0.05) and cross clamp time was 33+/-14 min for autotransfusion versus 43+/-17 min for cardiotomy (p less than 0.01). Total heparin dose was for 9500+/-2100 IU for autotransfusion versus 9800+/-1300 IU for cardiotomy (NS). The mean of the lowest ACTs measured during perfusion was 281+/-121 sec for autotransfusion versus 258+/-58 sec for cardiotomy (NS). The total protamine dose given was 7800+/-2100 IU for autotransfusion versus 9700+/-1900 IU for cardiotomy (p less than 0.05). The volume of washed red cells prepared was 3186+/-1318 ml for autotransfusion versus 0 for cardiotomy (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗