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M Porqueddu

Publications and source records attributed to M Porqueddu.

18 recordsLinked to original sources
PubMed2001

Determinants of early and late outcome after surgery for type A aortic dissection.

The aim of this study was to identify the most important variables associated with early and late mortality in patients operated on for type A aortic dissection over a 15-year period. From January 1984 to March 1999, 110 patients underwent surgery for type A aortic dissection. The 88.1% of patients had an acute type A dissection (AD) and 11.8% had a chronic dissection (CD). Cardiac tamponade and shock occurred in 21.8% and 14.5% of the patients, respectively. The location of the primary intimal tear was in the ascending aorta in 70.9% of cases, in the arch in 17.2%, and in the descending aorta in 7.2%. Univariate and multivariate analyses were conducted to identify non-embolic variables independently correlated to in-hospital death. Kaplan-Meier and Cox regression analyses and hazard function for death risk were used to analyze factors influencing overall and surgical survival. The overall in-hospital mortality rate was 20.9% (23/110 patients), being 9% for CD and 21.6% for AD. Emergent procedures had an in-hospital mortality rate of 47.6%, whereas nonemergent operations had an in-hospital mortality rate of 13.7% (p < 0.01). Univariate analysis revealed 41 preoperative and operative variables, including age (years), age >70 years, remote myocardial infarction, cerebrovascular dysfunction, diabetes, preoperative renal failure, shock, cardiopulmonary bypass time (minutes), emergency operation, as factors associated to in-hospital death (p < 0.05). Stepwise logistic regression analysis for in-hospital death selected as independent predicting variables (p < 0.05) remote myocardial infarction [p = 0.006, odds ratio (OR) = 1.9], preoperative renal failure (p = 0.031; OR = 0.8), shock (p = 0.001; OR = 3.1), and age >70 years (p = 0.007; OR = 1.7). Follow-up ranged from 9 to 172 months (median 78 months), with Kaplan-Meier survivals for all the patients and hospital survivors of 42% and 54% at 10 years, respectively. Cox regression analysis has identified postoperative stroke [relative risk (RR) = 3.7; p = 0.012), intimal tear in the aortic arch (RR = 2.3; p = 0.036), and postoperative renal failure (RR = 4.5; p = 0.007) as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, preoperative renal dysfunction (RR = 1; p = 0.013), reoperation (RR = 1.7;p = 0.004) and intimal tear in the aortic arch (RR = 1.2; p = 0.002) emerged as risk factors. The actuarial freedom from reoperation was 85.4% at 5 years. Multiple factors still influence early and late survival after surgery for type A aortic dissection. Preoperative renal impairment both affects early and late outcome. Early postoperative course affects late outcome in hospital survivors. The presence of the intimal tear in the aortic arch has a negative impact on late survival.

Adult↗
PubMed2001

Centrifugal pump and reduction of neurological risk in adult cardiac surgery.

This study was performed to assess if the kind of pump used for CPB (roller vs. centrifugal) can influence neurological outcomes of adult cardiac surgery patients. Between 1994 and 1998, 3438 patients underwent coronary and/or valve surgery at our hospital; of these, 1805 (52.5%) underwent surgery with the use of a centrifugal pump, and 1633 (47.5%) were operated with a roller pump. The effect of the type of the pump and of common preoperative and intraoperative risk factors for five different neurological outcomes (permanent neurological deficit, coma, delirium, transient neurological deficit, overall neurological complications) were assessed with univariate and multivariate analyses in the whole patients population, in patients > or = 75 years old and in patients with histories of previous neurological events. Centrifugal pump use was the only protective factor for perioperative permanent neurological deficit in multivariable models developed for the whole patient population and for patients > or = 75 years old. In addition, it resulted as the only protective factor for perioperative coma occurrence in multivariable models developed for patients > or = 75 years old, and for patients with histories of previous neurological events. The use of the centrifugal pump provided a risk reduction for the considered events ranging from 23 to 84%. Centrifugal pump use can be helpful in reducing the occurrence of some of the most feared neurological complications of adult cardiac surgery patients.

Aged↗
PubMed2000

Cosgrove-Edwards Annuloplasty System: midterm results.

BACKGROUND: The Cosgrove-Edwards Annuloplasty System includes a universally flexible band that corrects mitral annular dilatation via measured plication of the posterior annulus. The purpose of this study was to evaluate midterm clinical and functional results in the first 197 patients receiving this flexible annuloplasty band at mitral valve repair. METHODS: From February 1993 to July 1994, 197 consecutive patients with mitral regurgitation had mitral valve repair using this system. Valve disease was degenerative in 73%, rheumatic in 15%, ischemic in 5%, infectious in 2.5%, and other in 4%. RESULTS: Immediately after repair, echocardiographic mitral regurgitation was none or trivial in 92%, 1+ in 5%, and 2+ in 3%. There were no hospital deaths. Late follow-up was available in 195 patients (99%), with 661 patient-years of follow-up available for analysis. Four-year actuarial survival was 93%, freedom from thromboembolism 94%, from endocarditis 98%, and from reoperation 95%. At a mean interval of 18 months, echocardiography in 157 patients demonstrated no or trace mitral regurgitation in 56%, 1+ in 24%, 2+ in 9%, 3+ in 6%, and 4+ in 3%. At a mean of 61 +/- 5 months, reconstruction of the mitral annulus from real-time three-dimensional echocardiographic images in 10 patients confirmed preserved nonplanar shape and sphincter mechanism of the mitral annulus. Annular orifice area decreased 28% +/- 11% during the cardiac cycle from a mean of 10.1 +/- 3.9 cm2 in diastole to 7.2 +/- 2.8 cm2 in systole. CONCLUSIONS: This annuloplasty system is effective for repair of mitral regurgitation secondary to all causes and preserves mitral annular flexibility and function at 5-year follow-up.

Female↗
PubMed1999

Quick, simple clamping technique in descending thoracic aortic aneurysm repair.

BACKGROUND: Although significant advances have been made in the surgical treatment of diseases affecting the descending thoracic aorta, paraplegia remains a devastating complication. We propose the quick, simple clamping technique to prevent spinal cord ischemic injury. METHODS: From 1983 to 1998, 143 patients had descending thoracic aorta aneurysm repair. We divided the patients into the following three groups according to the surgical technique used: selective atriodistal bypass was used in group 1 (66 patients); simple clamping technique in group 2 (28 patients); and quick simple clamping technique in group 3 (49 patients). Mean aortic cross clamp time was 39+/-13 minutes in group 1, 37+/-11 minutes in group 2, and 17+/-6 minutes in group 3 (p<0.01 group 3 versus group 1 and group 2). RESULTS: The overall incidence of paraplegia was 4.8% (7 patients), 4.5% (3 patients) in group 1, 14.3% (4 patients) in group 2, and 0 in group 3 (p<0.05 group 3 versus group 2). The overall in-hospital mortality rate was 5.5%. Multivariate logistic regression analysis showed a powerful effect of aortic cross-clamping time as risk factor for both paraplegia (p<0.008), with an odds ratio of 1.03 per minute, and in-hospital mortality (p<0.001), with an odds ratio of 2.5 per minute. The mean follow-up time was 65 months with a lower overall mortality rate in group 3 than in group 1 and group 2 (p<0.05). CONCLUSION: In descending thoracic aortic aneurysm repair, spinal cord perfusion can be maintained adequately without reimplantation of segmental vessels or use of atriodistal bypass when the aortic cross-clamp time is short (<15 to 20 minutes).

Aortic Aneurysm, Thoracic↗
PubMed1999

Cardiopulmonary bypass and oxygen consumption: oxygen delivery and hemodynamics.

BACKGROUND: This study was undertaken to investigate the relations between whole body oxygen consumption (VO2), oxygen delivery (DO2), and hemodynamic variables during cardiopulmonary bypass. METHODS: One hundred one patients were studied during cooling, hypothermia, and rewarming. Oxygen consumption, DO2, hemodynamics, and DO2crit were measured at these times. RESULTS: There was a direct linear relation between DO2 and VO2 during all three times. No relation between VO2 and hemodynamics was detected during cooling; during hypothermia, an inverse linear relation with peripheral arterial resistance was found. Finally, during rewarming, there was a direct relation with pump flow rate, and an inverse relation with arterial pressure and arterial resistance. The same relations among the variables were found at delivery levels above or below DO2crit. CONCLUSIONS: During cardiopulmonary bypass there is a direct linear relation between DO2 and VO2; the relations with hemodynamic variables depend on the phases of cardiopulmonary bypass. This suggests that increasing delivery levels may recruit and perfuse more vascular beds, and higher delivery levels are advisable during perfusion. During rewarming and hypothermia, lower arterial resistances are also desirable to optimize VO2.

Aged↗
PubMed1998

Endothelial-dependent dynamic and antithrombotic properties of porcine aortic and pulmonary valves.

BACKGROUND: In the present study, the endothelium-dependent antithrombotic and dynamic properties of porcine aortic (AoV) and pulmonary valves (PuV) were investigated. METHODS: Fifteen fresh AoV and 15 fresh PuV were obtained from 25 9-month-old swines. The valves were examined for endothelial function by pharmacologic evaluation (with and without endothelium) of both the endothelial-releasing capacity of prostacyclin and the endothelial-dependent dynamic response to relaxing (acetylcholine from 10[-10] mol/L to 10[-4] mol/L in AoV and PuV segments precontracted with norepinephrine [3 x 10(-6) mol/L]) and contracting (endothelin-1, from 10[-11] mol/L to 10[-5] mol/L; and NG-monomethyl-L-arginine, 10[-4] mol/L) drugs. The ultrastructural integrity of the endothelial valve layer was also examined with transmission electron microscopy. RESULTS: Acetylcholine caused potent relaxation in both AoV and PuV specimens with, but not in those without, endothelium. Endothelin-1 produced a concentration-dependent tension increase in AoV and PuV with and without endothelium. However, the intrinsic activity of the peptide significantly increased in tissues without endothelium. NG-monomethyl-L-arginine evoked a progressive increase in resting tension of the preparations, but the AoV and PuV without endothelium were less sensitive to the inhibition of the nitric oxide generation. Aortic and pulmonary valves with an intact endothelium showed a spontaneous ability to release prostacyclin. The basal release of this lipidic autacoid significantly decreased in cardiac valves without endothelium. This phenomenon was observed in both basal conditions, and under stimulation with the aforementioned drugs. Transmission electron microscopy showed the perfect preservation of endothelial cells in all the preparations examined. CONCLUSIONS: Valvular endothelium of AoV and PuV seems to have similar antithrombotic and dynamic functions of vascular endothelium, actively participating in valvular homeostasis.

Acetylcholine↗
PubMed1997

Effects of warm ischemia on valve endothelium.

BACKGROUND: This study investigates the time-dependent resistance of the endothelium of porcine aortic and pulmonary valves to different periods of warm ischemia (WIT). METHODS: Twenty-five 9-month-old swine were divided after death into five groups of WIT (0, 6, 12, 24, and 36 hours). Aortic and pulmonary valves were removed and a total of 15 aortic and 15 pulmonary valve specimens were obtained for each WIT interval. Valves were then examined for (1) their viability rate by the trypan blue dye exclusion method at light microscopy (percent of viability compared with 0 hours of WIT); (2) ultrastructural signs of irreversible or reversible ischemic damage by transmission electron microscopy (cell disruption, dilation of endoplasmic reticulum, cytoplasmic edema, nuclear and mitochondrial changes); (3) endothelial function by pharmacologic evaluation of both the endothelial-releasing capacity of prostacyclin and the endothelial-dependent dynamic responses to relaxing (acetylcholine from 1 x 10(-10) mol/L to 1 x 10(-4) mol/L) in aortic and pulmonary valve segments precontracted with norepinephrine (1 x 10(-6) mol/L) and contracting (NG-monomethyl-L-arginine, 1 x 10(-4) mol/L) drugs. RESULTS: Our results showed an endothelial progressive time-dependent ischemic injury, which reached significance after 12 hours of exposure. Viability and functional data indicated that 6 hours of WIT only provoked slight endothelial damage (p > 0.05 respect to time 0 hours), with signs at transmission electron microscopy consistent with a reversible injury. At 12 hours of exposure, we observed a significant reduction (p < 0.05) with respect to time 0 of the viability rate of prostacyclin production and of the endothelium-dependent dynamic responses to acetylcholine and NG-monomethyl-L-arginine. These functional impairments, although significant, were not consistent, however, with a complete loss of viability. Transmission electron microscopic observations confirmed the appearance of signs of irreversible injury; nevertheless, some elements were found to be well preserved or presented reversible damage. After 24 hours of WIT, ultrastructural and functional data were consistent with a dramatic decrease compared with controls in endothelial viability and functions (p < 0.01). Finally, after 36 hours of WIT, there was a subtotal loss of viability, of functions (p < 0.001) and, at transmission electron microscopic observations, of the endothelial layer of the valves. CONCLUSIONS: Our data show that the endothelial cells are resistant to short periods of WIT (up to 6 hours), and suggest that these cells can endure longer exposures, up to 12 hours of warm ischemia. Periods of 24 and 36 hours of WIT provoke progressive irreversible damage.

Acetylcholine↗
PubMed1997

[Cellular viability and immune response in homologous cryopreserved cardiac valves].

BACKGROUND: Long-term durability of homograft valves is related to cellular viability and immunological compatibility. In this paper, we carry out a critical update of the relationship between cellular viability and immunology of cryopreserved homograft valves. BIOLOGICAL ISSUE: In the first section, we review the theoretical background of the superior durability of cryopreserved valves with high cellular viability, with respect to the "fresh" antibiotic-stored valves, with lower viability rates. Afterwards, a brief review of the principal factors influencing the homograft valve viability rate during harvesting, preparation, sterilization and cryopreservation phases, is performed. CELLULAR VIABILITY: In the second paragraph, we analyze the problem of cellular viability in cryopreserved valves, both for matrix cells--fibroblast--and for endothelium. In particular, we report the current methods of quantifications of viability and more recent biological researches. Correlations between biological and clinical data are also discussed. IMMUNOLOGICAL ISSUE: Finally, the immunological issue and its relationships with cellular viability is analyzed, with particular regard to experimental evidence and clinical implications. Moreover, we have described the recent hypothesis on the influence of cryopreservation on the antigenicity of tissues, and the laboratory researches on the long-term antibody response in humans after homograft valve implantation.

Cell Survival↗
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

Retention of endothelium-dependent properties in human mammary arteries after cryopreservation.

BACKGROUND: We investigated the effects of cryopreservation and antibiotic treatment on endothelium-dependent vasomotor properties of human internal mammary arteries (IMAs). METHODS: Sixty IMA specimens from routine coronary artery bypass grafting procedures were randomly assigned to six groups. Group I (controls) were immediately tested after harvest. Remaining groups were prepared according to a stepwise design: group II, 6 hours of warm ischemia; group III, 6 hours of warm ischemia + 24 hours at 4 degrees C (without antibiotics); group IV, 6 hours of warm ischemia + 24 hours of 4 degrees C antibiotic disinfection; group V, 6 hours of warm ischemia + 24 hours at 4 degrees C (without antibiotics) + cryopreservation; and group VI, 6 hours of warm ischemia + 24 hours of 4 degrees C disinfection+cryopreservation. The IMA specimens were cut into rings and the tension of vascular smooth muscle was recorded. The IMA rings were contracted with norepinephrine (3 x 10(-6) mol/L) and tested with cumulative concentrations of acetylcholine (from 1 x 10(-9) to 1 x 10(-5) mol/L), contracted with endothelin-1 (from 1 x 10(-11) to 1 x 10(-6) mol/L), and contracted with the nitric oxide-synthase inhibitor NG-monomethyl-L-arginine (1 x 10(-4) mol/L). Rings were also tested for their capacity to generate 6-keto-prostaglandin F1 (the stable metabolite of prostacyclin), and endothelial cell viability rate was finally evaluated with the trypan blue dye exclusion method. RESULTS: Our results show that a complete cryopreservation protocol does not significantly modify (p > 0.05) the relaxant activity to acetylcholine in norepinephrine-precontracted IMA rings (controls; 90.2% +/- 4.2% vs group VI, 77.1% +/- 6.2%) or the vasoconstrictor response induced by endothelin-1 (controls, 62.6% +/- 2.8% versus group VI, 73.7% +/- 4.8%) and NG-monomethyl-L-arginine (controls, 22.4% +/- 1.5% versus group VI, 18.9% +/- 1.9%). Furthermore, IMA cryopreservation does not significantly modify (p > 0.05) the endothelial release of prostacyclin either in basal conditions (-20% versus controls) or during pharmacologic intervention with acetylcholine (-18% versus controls), endothelin-1 (-17% versus controls), and NG-monomethyl-L-arginine (-18% versus controls). CONCLUSIONS: We conclude that the IMA endothelial function does not seem significantly injured by any of the current steps of disinfection and cryopreservation.

6-Ketoprostaglandin F1 alpha↗
PubMed1995

Ectopic thyroid tissue in the ventricular outflow tract: embryologic implications.

The case of a 66-year-old female patient with a tumor located in the right ventricular outflow tract is reported. Histologic examination of an intraoperative biopsy revealed that the tumor was an intracardiac ectopic thyroid. We performed conservative surgery with partial resection of the mass. After 5 years, the patient is asymptomatic and leading a normal life. The authors examine the relation between the embryologic development of the primitive heart and the thyroid primordium and suggest the hypothesis of ectopic thyroid location in the right- or left-ventricular outflow tract.

Aged↗
PubMed1994

[Myocardial revascularization in aged patients: what is the surgical risk?].

There are still controversies about the surgical results of myocardial revascularization in aged population, in terms of cardiac and non-cardiac morbidity and mortality. This issue prompted us to study retrospectively 71 patients older than 75 years electively operated of coronary artery bypass grafting (CABG) from June 1990 to June 1993 (Group A). Elderly population was compared with a contemporaneous and concurrent control group of patients younger than 75 years (Group B). Patients > 75 years have been divided in successive subgroups according to the severity of coronary artery disease (3 vessel disease 67.7%, 2 vessel disease 26.7%, 1 vessel disease 5.6%), echocardiographic ejection fraction (EF > 50%: 40.8%; 50-30%: 42.2%; < 30%: 16.9%) and preoperative risk factors. Left internal thoracic artery (LITA) utilization rate was 97.1% in Group B and 57.7% in Group A (p < 0.001). Cardiopulmonary bypass circulation, aortic cross-clamping time and number of coronary anastomoses were similar in the 2 groups (2.87 +/- 0.9 versus 2.8 +/- 0.8, NS). Operative mortality rate of aged population was 4.2% while no patient of Group B died (NS). Concerning the cardiac morbidity, there were no significantly differences between the 2 groups: myocardial infarction occurred in 3 patients of Group B (4.2%) and in 5 patients of Group A (7%; NS). Atrioventricular block was also similar in the 2 groups. Non-cardiac complications occurred more frequently in the aged population group: neurologic complications in 11.2% versus 1.4% (p < 0.04), renal insufficiency in 12.6% versus 1.4% (p < 0.03) and respiratory failure in 9.8% versus 1.4% (p = 0.06). (ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1993

Intracardiac ectopic thyroid: conservative surgical treatment.

The case of a patient with an intracardiac ectopic thyroid is reported. A cardiac tumor was found in a 66-year-old woman and was diagnosed by two-dimensional echocardiography. An intraoperative biopsy was performed, and the mass was recognized as an ectopic thyroid and treated with a conservative surgical approach because of the size, location, and relationship to adjacent structures. The 60-month follow-up shows normal echocardiographic images and the good clinical status of the patient.

Aged↗
PubMedDate not supplied

Protectant activity of defibrotide in cardioplegia followed by ischemia/reperfusion injury in the isolated rat heart.

BACKGROUND: Previous studies have shown that defibrotide, a polydeoxyribonucleotide obtained by depolymerization of DNA from porcine tissues, has important protective effects on myocardial ischemia, which may be associated with a prostacyclin-related mechanism. The purpose of this study was to investigate the direct effects of defibrotide (given in cardioplegia or after ischemia) on a model of rat heart recovery after cardioplegia followed by ischemia/reperfusion injury. METHODS: Isolated rat hearts, undergoing 5 minutes of warm cardioplegic arrest followed by 20 minutes of global ischemia and 30 minutes of reperfusion, were studied using the modified Langendorff model. The cardioplegia consisted of St. Thomas' Hospital solution augmented with defibrotide (50, 100, and 200 microg/mL) or without defibrotide (controls). Left ventricular mechanical function and the levels of creatine kinase, lactate dehydrogenase, and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha; the stable metabolite of prostacyclin) were measured during preischemic and reperfusion periods. RESULTS: After global ischemia, hearts receiving defibrotide in the cardioplegic solution (n = 8) manifested in a concentration-dependent fashion lower left ventricular end-diastolic pressure (p < 0.001), higher left ventricular developed pressure (p < 0.01), and lower coronary perfusion pressure (p < 0.001) compared to the control group. After reperfusion, hearts receiving defibrotide in the cardioplegic solution also had, in a dose-dependent way, lower levels of creatine-kinase (p < 0.01), lactate dehydrogenase (p < 0.001), and higher levels of 6-keto-PGF1alpha (p < 0.001) compared to the control group. Furthermore, when defibrotide was given alone to the hearts at the beginning of reperfusion (n = 7), the recovery of postischemic left ventricular function was inferior (p < 0.05) to that obtained when defibrotide was given in cardioplegia. CONCLUSIONS: Defibrotide confers to conventional crystalloid cardioplegia a potent concentration-dependent protective effect on the recovery of isolated rat heart undergoing ischemia/reperfusion injury. The low cost and the absence of contraindications (cardiac toxicity and hemodynamic effects) make defibrotide a promising augmentation to cardioplegia.

Animals↗