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A Parolari

Publications and source records attributed to A Parolari.

At least 37 records · Page 2Linked to original sources
PubMed1999

Platelet function and anesthetics in cardiac surgery: an in vitro and ex vivo study.

UNLABELLED: We studied the effects of the anesthetics commonly used in cardiac surgery on platelet function. Fentanyl, droperidol, succinylcholine, pancuronium, thiopental, and diazepam at therapeutic concentrations were tested for their in vitro effects on the expression of platelet membrane glycoproteins Ib and IIbIIIa (GpIb, GpIIb-IIIa) and of P-selectin in anticoagulated whole blood by flow cytometry. The expression of P-selectin was determined under basal conditions, after the incubation of blood with adenosine diphosphate (ADP) 10 micromol/L, and the stable prostaglandin endoperoxide analog U46619 1 micromol/L. No drug affected the expression of P-selectin in unstimulated and ADP- or U46619-stimulated platelets, with the exception of thiopental, which markedly decreased the U46619-induced expression of P-selectin. Thiopental concentration-dependently inhibited U46619-induced and ADP-induced platelet aggregation, with effects on U46619-induced aggregation at therapeutic concentrations. To assess ex vivo effects, the same platelet markers were also assessed in blood obtained from 10 patients undergoing elective coronary surgery. Compared with basal values, platelet response to U46619 was significantly reduced just after the administration of anesthetic drugs, and the effect persisted for 48 h after surgery. Our study suggests that, at therapeutic concentrations, thiopental inhibits U46619-induced platelet activation both in vitro and ex vivo. The mechanisms responsible of this effect, together with its clinical significance, require further investigation. IMPLICATIONS: Thiopental inhibited prostaglandin-induced platelet activation at therapeutic concentrations both in vitro and ex vivo in cardiac surgical patients whereas adenosine diphosphate-induced activation was affected only at supratherapeutic drug concentrations. Thus, administration of sodium thiopental may contribute to the in vivo impairment of platelet function in patients undergoing elective cardiac surgery.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1999

Amino acids are compatible osmolytes for volume recovery after hypertonic shrinkage in vascular endothelial cells.

The response to chronic hypertonic stress has been studied in human endothelial cells derived from saphenous veins. In complete growth medium the full recovery of cell volume requires several hours and is neither associated with an increase in cell K+ nor hindered by bumetanide but depends on an increased intracellular pool of amino acids. The highest increase is exhibited by neutral amino acid substrates of transport system A, such as glutamine and proline, and by the anionic amino acid glutamate. Transport system A is markedly stimulated on hypertonic stress, with an increase in activity roughly proportional to the extent and the duration of the osmotic shrinkage. Cycloheximide prevents the increase in transport activity of system A and the recovery of cell volume. It is concluded that human endothelial cells counteract hypertonic stress through the stimulation of transport system A and the consequent expansion of the intracellular amino acid pool.

Amino Acids↗
PubMed1998

[Oxygen consumption during cardiovascular surgery conducted under extra-corporeal circulation].

Whole-body oxygen consumption (VO2) is universally considered both a measure of the metabolic activity of the body and an indicator of the adequacy of tissue perfusion during cardiopulmonary bypass as well. There is little agreement in the literature about the main determinants of oxygen consumption during CPB, except for the role of temperature in reducing the metabolic activity of the body. Many studies, which have been performed both on animals and in humans, have reached some contradictory conclusions about the role of delivery and perfusion flow rates, of haemodynamic variables, of the acid-base status, and of drugs influencing the variations of oxygen consumption during CPB. Aim of this paper is to review the evidences in literature about the determinants of whole-body oxygen consumption during cardiopulmonary bypass in man.

Cardiopulmonary Bypass↗
PubMed1997

Hypertonicity induces injury to cultured human endothelium: attenuation by glutamine.

BACKGROUND: Although most preservation solutions as well as some cardioplegic solutions used for organ storage and transplantation are hypertonic, the effects of extracellular hypertonicity on endothelium are not well established. Aims of this study were to evaluate the response of cultured human saphenous vein endothelial cells to extracellular hypertonicity and to investigate the role of the amino acid glutamine in preventing endothelial damage in vitro. METHODS: Eight distinct strains of human saphenous vein endothelial cells were studied. Hypertonic (350 and 400 mosm/kg) media were obtained by supplementing culture medium with sucrose. Cell viability was assessed in the absence or the presence of glutamine through the determination of cell number and protein content of the cultures. Confocal microscopy of cells loaded with the fluorescent dye calcein was also performed. RESULTS: Exposure of human saphenous vein endothelial cells to hypertonic media without glutamine caused significant cell loss within 30 minutes. Cell loss progressed steadily during incubation and after 6 hours reached 50% at 350 mosm/kg and 65% at 400 mosm/kg. In the presence of 2 mmol/L glutamine, endothelial damage was completely prevented at 350 mosm/kg and significantly lessened at 400 mosm/kg compared with glutamine-free media. Confocal microscopy showed that most hypertonicity-treated cells exhibited the typical features of an apoptotic death and confirmed the osmoprotective effect of glutamine. CONCLUSIONS: These results indicate that the supplementation of hypertonic storage solutions with glutamine might exert a partial osmoprotective effect and suggest that the relationship between endothelial damage and tonicity of storage and cardioplegic solutions should be carefully investigated.

Aged↗
PubMed1997

Surgery of descending thoracic aortic aneurysms with centrifugal pump support.

Fifty-five patients with descending thoracic aortic aneurysms were operated upon between October 1987 and October 1994. All patients were supported by a centrifugal pump during operation. The mean(s.d.) duration of cross-clamping was 39(13) min. In order to evaluate the efficacy of the centrifugal pump, haemodynamic and metabolic measurements were made on four occasions (before cross-clamping, immediately after cross-clamping and before cross-clamp removal) and again after cross-clamp removal. The haemodynamic data remained stable throughout the procedure: central venous pressure (15(4.6) versus 16(4.8) versus 16(4.6) versus 15(4.6) mmHg; P = n.s.), pulmonary artery pressure (25(6.2) versus 24(5.1) versus 22(5.3) versus 23(4.4) mmHg; P = n.s.), radial systolic pressure (119(19.9) versus 116(25.2) versus 111(25.9) versus 111(20.7) mmHg; P = n.s.) and heart rate (75(12.6) versus 77(14) versus 76(15.6) versus 78(16) beats/min; P = n.s.). The acid-base status deteriorated slowly during surgery. Values before and after cross-clamping were: pH (7.42 (0.04) versus 7.37(0.06); P < 0.05), base excess (-0.67(2.20) versus -3.70(2.50); P < 0.05) and bicarbonates (24(8.9) versus 20(1.9); P < 0.05). The cerebrospinal fluid pressure remained constant: 20(5.7) versus 19(5.9) versus 18(5) versus 19(5) mmHg; P = n.s. Renal function, measured before, and at 1, 3 and 7 days after the operation also remained stable (creatinine: 1.1(0.4) versus 1.2(0.4) versus 1.2(0.4) versus 1.2(0.4); P = n.s.; blood urea nitrogen: 46(18.7) versus 46(18.6) versus 51(24.9) versus 55(27.9); P = n.s.). Step-wise multiple linear regression comparing cerebrospinal fluid pressure against haemodynamic and metabolic data showed that during aortic cross-clamping there was a significant relationship between central venous pressure (P < 0.0013) and arterial pH (P < 0.0148), while before and after cross-clamping multivariate analysis showed a relationship only between central venous pressure and cerebrospinal fluid pressure (P < 0.0035). The results confirm that centrifugal pump support is effective in stabilizing haemodynamics and protecting the kidney during thoracoabdominal aneurysm repair.

Acid-Base Equilibrium↗
PubMed1997

Non-invasive evaluation of right gastroepiploic artery with colour Doppler echography.

The right gastroepiploic artery has been increasingly used as a coronary bypass graft. Short- and mid-term patency rates support the supposition that the right gastroepiploic artery is a satisfactory bypass conduit. However, conclusive angiographic data on long-term patency rates are still lacking. An echo-colour Doppler method was used to detect patency of the right gastroepiploic artery grafts through an upper abdominal approach. A group of 24 patients with a right gastroepiploic artery graft to the right or posterior descending coronary artery, all of whom also had a postoperative angiographic study which showed 100% patency of the graft were used as a reference group. A second group of 89 patients was also investigated only with echo-colour Doppler during the postoperative period (mean 8.0 (range 1-48) months). A patent right gastroepiploic artery graft showed a biphasic velocity pattern. Systolic peak velocity ranged from 8 to 26 cm and diastolic peak velocity from 4 to 13 cm. The right gastroepiploic artery diameter ranged from 1.7 to 2.4 mm and flow from 10.2 to 58.8 ml. Among the second group were three patients who had, at their echo-colour Doppler examination, a possible occlusion of the right gastroepiploic artery graft; an angiographic study was conducted and the graft closure confirmed in all cases. Serial echo-colour Doppler evaluation of the right gastroepiploic artery blood flow pattern and diameter is a non-invasive and safe method to check the patency and flow capacity of the artery graft in follow-up studies.

Adult↗
PubMed1997

Aprotinin and deep hypothermic circulatory arrest: there are no benefits even when appropriate amounts of heparin are given.

OBJECTIVE: To evaluate retrospectively the effect of 'high-dose' aprotinin on blood losses, donor blood requirements and morbid events on patients undergoing ascending aorta and/or aortic arch procedures with the employ of deep hypothermic circulatory arrest (HCA). METHODS: During the period 1987-1994, 39 patients underwent a thoracic aorta procedure with the employ of circulatory arrest; of these 18 (46.2%) were operated on during the period 1990-1994 and were given aprotinin intraoperatively following the 'high-dose' protocol (group I), while 21 (53.8%) who underwent surgery during the years 1987-1989, did not receive intraoperative aprotinin and served as historical controls (group II). Twenty-seven (69.2%) patients were male, 18 (46.2%) were operated on on an emergency basis, 15 (38.5%) were acute type A dissections, and two (5.1%) were redo-operations. Circulatory arrest times were not significantly different between the two groups (40 +/- 4 (S.E.) group I vs. 43 +/- 4 min group II, P = 0.62) likewise cardiopulmonary bypass (CPB) times (181 +/- 9 vs. 201 +/- 20 mm, P = 0.74) and the amount of heparin administered (32056 +/- 1435 vs. 31 691 +/- 1935 IU, P = 0.56). RESULTS: Postoperative blood loss was comparable between the two groups (1213 +/- 243 (median 850) group I vs. 1528 +/- 377 (median 880) ml group II, P = 0.87), as well as the number of units of donor blood transfused (9.4 +/- 3.0 (median 6) vs. 9.9 +/- 3.6, (median 5) P = 0.87), and revisions for bleeding (2/18, 11.1% vs. 3/21, 14.3%, P = 0.77). In-hospital mortality rate was not statistically different (5/18, 27.7% group I vs. 6/21, 28.6% group II, P = 0.92). There were no significant differences between the two groups in myocardial infarction (2/18, 11.1% vs. 0/21, 0%, P = 0.21), and postoperative renal failure rates (3/18, 16.7% vs. 2/21, 9.5%, P = 0.65). On the other hand, there was a trend towards an increased incidence of permanent neurological deficit (5/18, 27.7% group I vs. 1/21, 4.8% group II, P = 0.07) and towards a more complicated postoperative course (perioperative renal failure and/or myocardial infarction and/or neurological deficit either transient or permanent) (8/18, 44.4% group I vs. 4/21, 19% group II, P = 0.09) in group I patients. Forward stepwise logistic regression analysis, performed on the whole group of patients, identified chronic obstructive pulmonary disease (P = 0.010, Odds ratio (OR) = 5.7), aprotinin use (P = 0.017, OR = 5.1), and the number of units of blood collected intraoperatively by the cellsaver (P = 0.045, OR = 1.3/unit) as independent predictors of complicated postoperative course in the whole group of patients. CPB time (P = 0.040, OR = 1.032/min), circulatory arrest time (P = 0.053, OR = 1.22/min), and overall donor blood units transfused (P = 0.067, OR = 1.37/unit) emerged as independent risk factors for in-hospital mortality at multivariate analysis. CONCLUSIONS: Even when appropriate amounts of heparin are administered, 'high-dose' aprotinin probably is not an effective blood-sparing drug in deep HCA. Aprotinin should be employed cautiously in this clinical setting because of its possible correlation with an increased rate of postoperative morbid events.

Aged↗
PubMed1997

Mid-term follow-up of 183 arterial myocardial revascularization procedures.

OBJECTIVE: To evaluate the mid-term results of complete arterial myocardial revascularization performed with arterial conduits. METHODS: From July 1987 to December 1994, 183 patients underwent a myocardial revascularization procedure with the use of at least two arterial grafts (IMAs, rGEA, IEA) at our institute. Their mean age was 56 +/- 8.7 years, the redo-operation rate was 16.9% (31/183), two-vessel disease was present in 61 patients (33.3%), three-vessel disease in 122 (66.7%). RESULTS: The LIMA was used in 179 patients (97.8%), the RIMA in 116 (63.4%), the rGEA in 66 (36.1%) and the IEA in 41 (22.4%). In-hospital mortality was 1.1% (2/183), while the perioperative myocardial infarction (MI) rate was 2.2% (4/183). The angiographic restudy, performed on 87 (47.5%) patients during the early postoperative period (median 38 days) showed the following grafts patency rates: LIMA 98.8 (86/87), RIMA 97.1 (34/35), IEA 85.7 (24/28), rGEA 97.05 (33/34) and saphenous vein 90.9% (10/11). The median follow-up was 35 months. Kaplan-Meier survival was 96 +/- 2% at 3 and 5 years, freedom from angina 94 +/- 2% at 3 years and 91 +/- 3% at 5 years, while the Kaplan-Meier freedom from cardiac events was 90 +/- 3% at 3 years and 88 +/- 3% at 5 years. Cox regression analysis identified perioperative MI (P = 0.03, relative risk 3.6) as the only prognostic factor for mortality at follow-up. With regards to recurrence of angina, multivariate analysis has shown that incremental risk factors for the return of angina are redo-operation (P < 0.01, relative risk 2.7) and the persistence of hypertension after surgery (P < 0.01; relative risk 3.2), while the use of the RIMA in the operation has emerged as a protective factor (P = 0.02; relative risk 0.43). Finally, only redo-operation (P < 0.01; relative risk 2.3), has emerged as a predictor of cardiac complications. CONCLUSION: Myocardial revascularization with at least two arterial grafts can be performed with very low perioperative morbidity and mortality and good mid-term follow-up. The mid-term results of arterial myocardial revascularization are less favourable in cases of redo-operations or when the RIMA is not used.

Actuarial Analysis↗
PubMed1997

[Surgical therapy for prosthetic infections of the thoracic aorta. Conservative approach].

The prosthetic graft infection of the thoracic aorta is a dreaded complication and it is associated with a high mortality rate. There is not substantial agreement in literature about how to manage a vascular graft infection, except for local anti-septic irrigation with a systemic antibiotic therapy. The main point of discussion is if it is mandatory to remove or not the infected thoracic aorta prosthesis: some authors prefer to eliminate all the thoracic aortic prostheses which may be infected, while others propose graft removal only when the sutures lines are involved. In this paper we report our experience on the conservative management of infected thoracic aorta prostheses using a local antiseptic irrigation, a perigraft debridement and leaving the original graft "in situ" when there is evidence of graft damage especially or involvement of the sutures lines. This approach has been performed in three patients: two had an infected aortic arch prosthesis, while one had a descending thoracic aorta prosthesis infection.

Aorta, Thoracic↗
PubMed1997

[Surgery of the ascending aorta: the 1984-1995 experience of the cardiac surgery teaching unit in the University of Milan. Multivariate analysis of its risk factors for hospital mortality and reduced long-term survival].

Between 1984 and 1995, 183 patients underwent an ascending aorta procedure at our institution. Their mean age was 60 +/- 12.3 years; 116 (63.4%) patients were male, 35 (19.1%) had a history of congestive heart failure, 72 (39.3%) presented acute type A dissection, 23 (12.6%) were redos and 63 (34.4%) were operated on an emergency basis. In-hospital mortality was 10% (12/120) in elective procedures and 36.5% (23/63) in emergency operations (p < 0.0001). Multivariate stepwise logistic regression analysis identified cardiopulmonary by-pass time, emergency operation, arch replacement and the need for femoral vein cannulation at surgery as independent predictors of in-hospital death. Mean follow-up time was 54 +/- 30 months (median 50 months), with a Kaplan-Meier survival of 69 +/- 4% and of 60 +/- 5% at 5 and 7 years, respectively. Cox regression analysis identified arch replacement, perioperative myocardial infarction, preoperative NYHA class, acute type A aortic dissection, the need for femoral vein cannulation at intervention and redo operations as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, postoperative tracheostomy, reexploration for bleeding, and the occurrence of postoperative ventricular arrhythmias emerged as risk factors. In conclusion, multiple factors affect both early and long-term outcome following ascending aorta surgery. Preoperative clinical status of patients, priority of surgery and aortic dissection are the main determinants of the short-term results. Otherwise, in hospital survivors, the main determinant for long-term outcome seems to be the immediate postoperative course.

Aged↗
PubMed1996

Midterm angiographic study of five recycled mammary arteries during four coronary redos.

BACKGROUND: Recently the technical feasibility of reusing the left internal mammary artery (IMA) in coronary artery reoperation has been documented, but the patency of "recycled" IMAs has not yet been established. METHODS: In 4 patients undergoing coronary reoperation, five internal mammary arteries (3 left IMAs and 2 right IMAs) that were patent but severely stenotic at the anastomotic site were taken down and reused. In 2 cases the IMAs were reanastomosed to the same target coronary artery, in 2 cases the IMAs were rerouted to another coronary artery, and in 1 case an interposition of a short segment of the greater saphenous vein was needed to reach the target coronary artery. RESULTS: Angiographic midterm evaluation, performed between 7 and 35 months postoperatively, showed patency of all the reused grafts without stenoses. CONCLUSIONS: When feasible, recycling of the IMAs may be considered if one or both IMAs have been previously used and are stenotic in the perianastomotic area, or when there is a stenosis in the native coronary artery distal to the anastomosis itself.

Adult↗
PubMed1996

[Heart surgery, cardiopulmonary bypass and inflammatory response. I. Changes in hemostasis and complement].

The use of cardiopulmonary bypass for surgical cardiac procedures is characterized by a whole-body inflammatory reaction due to the contact of blood through nonendothelialized surfaces; this stimulates the organism to recognize the cardiopulmonary bypass system as "nonself" and to activate specific (immune) and nonspecific (inflammatory) responses. These responses are then related with postoperative damage to many body systems, like pulmonary, renal or brain dysfunction, excessive bleeding and postoperative sepsis. In this paper, present knowledge on untoward responses of the patient to the use of cardiopulmonary bypass in cardiac surgery is reviewed and discussed, particularly focusing on the perturbation of the hemostasis and of the complement activation system.

Blood Coagulation↗
PubMed1996

[Heart surgery, cardiopulmonary bypass, and organic inflammatory response. Part II: changes in leukocytes, arachidonic acid derivatives, and hormones].

The use of cardiopulmonary bypass for surgical cardiac procedures is characterized by a whole-body inflammatory reaction due to the contact of blood through nonendothelialized surfaces; this stimulates the organism to recognize the cardiopulmonary bypass system as "nonself" and to activate specific (immune) and nonspecific (inflammatory) responses. These responses are then related with postoperative damage to many body systems of the body, like pulmonary, renal or brain dysfunction, excessive bleeding and postoperative sepsis. In this paper, present knowledge on untoward responses of the patient to cardiopulmonary bypass in cardiac surgery is reviewed and discussed, particularly focusing on the perturbation of the leukocytes, of the hormones and of the products of the arachidonic acid cascade.

Arachidonic Acids↗
PubMed1996

Myocardial revascularization procedures on multisegment diseased left anterior descending artery: endarterectomy or multiple sequential anastomoses (jumping)?

Complete revascularization is the primary goal in coronary surgery because of its superior long term results. However, in some patients the extent of the coronary artery disease is such that the usual coronary bypass technique may not allow to perform a complete myocardial surgical revascularization and, consequently, a satisfactory myocardial perfusion: so complementary revascularization techniques may become mandatory, especially when the diseased vessel is LAD or its branches. As a consequence, alternative procedures should be undertaken: coronary endarterectomy (EA) and multiple sequential anastomoses on a single vessel (jump), which guidelines are actually somehow controversial. Between January, 1989, and May, 1992, 53 patients underwent a myocardial revascularization procedure on LAD system unsuitable for single distal bypass; of them 35 (66%) underwent coronary endarterectomy, while in 18 (34%) multiple sequential anastomoses (jumping) were performed on the same vessel. About preoperative variables, average NYHA class (2.7 jump vs 2.1 EA group, p < 0.05), the history of more than 1 myocardial infarction (22.2% jump vs 2.9% EA, p < 0.04) and the presence of preoperative nitrates e.v (33.3% vs 8.6%, p < 0.04) were statistically higher in the jump group, suggesting a more unstable clinical status, while other clinical echocardiographic and catheterization features were not statistically different. For what operative and postoperative features are concerned, the number of anastomoses performed was statistically higher in the jump group, as exasperated (3.8 vs 2.7, p < 0.002) while perfusion (138 vs 141 min) and crossclamp time (103 vs 106 min) were similar. Furthermore we found a statistically lower incidence of perioperative myocardial infarction (0% jump is 22.8% EA group, p < 0.04); the postperfusion inotropic drugs requirement (22.2% vs 37.1%), the need of an intraaortic counterpulsation (0% vs 2.9%) and the in-hospital mortality (0% vs 5.7%) were lower in the jumping group too, also if they didn't reach statistical significance. Our experience suggest, also with the limits imposed by a retrospective case review and by a low number of cases reported, that myocardial revascularization of a multisegment diseased LAD system may be safely performed with the jumping technique with a low incidence of postoperative complications: it should be the first choice technique when conventional revascularization procedures are not enough to achieve complete myocardial revascularization. We advocate the use of EA technique only in that cases characterized by a diffuse atherosclerotic core and a well delimited plane of dissection, associated to a very poor runoff, which really excludes any chance to multiple anastomoses.

Aged↗
PubMed1995

False hydatic aneurysm of the thoracic aorta.

In this article we report the successful treatment of a lower descending thoracic aorta hydatidosis that mimicked a posterior saccular aneurysm; surgical excision was performed and the aorta was repaired with a prosthetic Dacron patch. At a 26-month follow-up, the patient is alive and conducting a normal life. Discussion about the management of this rare case also is given.

Adult↗