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In the present study, we analyzed the effect of conditioned media (CM) from bovine aortic endothelial cells exposed to laminar shear stress (SS) of 5 dyne/cm2 (SS5) or 15 dyne/cm2 (SS15) for 16 hours on smooth muscle cell (SMC) migration. In response to CM from bovine aortic endothelial cells exposed to SS5 (CMSS5) and SS15 (CMSS15), migration was 45 +/- 5.5 and 30 +/- 1.5 cells per field, respectively (P<0.05). Similar results were obtained with SS of 2 versus 20 dyne/cm2 and also when SS of 5 and 15 dyne/cm2 lasted 24 hours. Platelet-derived growth factor (PDGF)-AA levels in CMSS5 and CMSS15 were 9 +/- 7 and 18 +/- 5 ng/10(6) cells for 16 hours, respectively (P<0.05); PDGF-BB levels in CMSS5 and CMSS15 were 38 +/- 10 and 53 +/- 10 ng/10(6) cells for 16 hours, respectively (P<0.05). PDGF receptor alpha (PDGFRalpha) and PDGF receptor beta (PDGFRbeta) in SMCs were phosphorylated by CMSS15>CMSS5. In response to CMSS15, a neutralizing antibody against PDGF-AA enhanced SMC migration to a level comparable to that of CMSS5; in contrast, antibodies against PDGF-BB abolished SMC migration. Transfection of SMCs with a dominant-negative PDGFRalpha or PDGFRbeta increased or inhibited, respectively, SMC migration in response to CMSS15. Overexpression of wild-type PDGFRalpha inhibited SMC migration in response to CMSS5, CMSS15, or recombinant PDGF-BB (P<0.001). These results suggest that the ability of high SS to inhibit arterial wall thickening in vivo may be related to enhanced activation of PDGFRalpha in SMCs by PDGF isoforms secreted by the endothelium.

A case of intimal-type primary sarcoma of the thoracic aorta with unusual left arm embolization is reported.

Background: Redo coronary artery bypass grafting (CABG) represents an high-risk surgical procedure, because of an increased incidence of perioperative death, myocardial infarction and stroke. Theoretically, the avoidance of cardiopulmonary bypass may reduce surgical traumatism and ameliorate early results., Materials and Methods: From January 1995 to May 2001, we performed 123 redo CABGs, of which 53 (44%) off-pump. Off-pump procedure represented respectively 90% of redo CABG in the period 2000-2001 versus 30% in the 1995-1999 period. The mean age was 66.4 years, males were 39 (73%). The mean 2D-echo ejection fraction was 56% and in 9 cases (17%) was less than 40%. Three operations (5.6%) were performed on an urgent base. The access was median sternotomy in all cases. The mean number of grafts per patient was 1.9 (1.7 in the period 1995-99 vs. 2.3 in the period 2000-01, p=0.01). In 20 cases (38%) we grafted the circumflex artery branches (19% in the period 1995-99 vs. 55.5% in the period 2000-01, p=0.015). Improvements in surgical techniques were achieved over time. The current operative strategy includes the use of deep traction stitches in the posterior pericardium and wall stabilizers to expose target vessels, coronary intraluminal shunts during construction of the anastomoses and continuous trans-esophageal echocardiographic monitoring. Urgent conversion to on-pump procedure was not required in any case., Results: We recorded no in-hospital death, one perioperative myocardial infarction (1.9%), one fifth postoperative day-stroke (1.9%) and 9 atrial fibrillations (17%). Mediastinal re-exploration for bleeding was performed in no one patient; 13 patients (24.5%) required postoperative blood transfusion. The mean length of postoperative stay was 7.5 days, ranging from 6 to 18 days., Conclusions: In our experience off-pump redo CABG is a safe and effective alternative to on-pump procedure and now off-pump is our first choice-technique in redo CABG. A complete revascularization is technically feasible with a low incidence of perioperative complications.

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.

Background: This study was undertaken to assess our experience of the evolution, over time, of beating heart surgery in the Cardiologic Center Foundation Monzino., Methods: From March 1995 to June 2000, 506 patients underwent myocardial revascularization on beating heart: 313 until May 1999, and 193 between June 1999 and June 2000, after the advent of coronary artery stabilizers and shunts, to keep the surgical field bloodless, with minimal motion and continuous myocardial perfusion. Surgical accesss was via a median sternotomy for 408 cases and via a left anterior thoracotomy for 98 cases., Results: The indications by choice increased, from I to II period, from 61% to 83% with special situations in which patients had three-vessel coronary artery disease raised from 33% to 50%, concerning also bypass grafts performed on circumflex artery and right coronary increased. Postoperative mortality in hospital decreased from 1.3% to 0.5% and perioperative IMA (acute myocardial infarction) from 3.8% to 0.5% in patients undertaken to median thoracotomy. Hospital stay decreased from 8 to 7 days about [no significant differences with patients who underwent CPB (cardiopulmonary bypass)]; in patients who underwent to MTS (left anterior minithoracotomy) there was no deaths, IMA decreased from 3.9% to 0% and hospital stay from 6 to 5 days. Grafts patency increased from 92.3% to 100%., Conclusions: To perform completed revascularisations is possible now even on the beating heart, and also to make precise anastomosis as on pump CABG, in a reproducible and easy way. The beating heart procedure, that is also more economical, might be expanded to all patients, not only high risk patients.

Background: Endothelium-dependent relaxation is abnormal in a variety of diseased states. Despite the widespread use of the internal mammary artery (IMA) in coronary artery bypass grafting, there is a lack of comparative studies on IMA endothelial-dependent function in patients with major cardiovascular risk factors., Methods: An IMA segment from 48 selected patients undergoing coronary artery bypass grafting was harvested intraoperatively and assigned to one of four groups (n = 12): diabetics requiring therapy, hypertensives, hypercholesterolemic, and nondiabetic-normotensive-normocholesterolemic patients. Internal mammary artery specimens were cut into rings and suspended in organ bath chambers, and the isometric tension of vascular tissues was recorded. The IMA rings were (1) precontracted with norepinephrine, and the endothelium-derived relaxation was evaluated by cumulative addition of acetylcholine, (2) contracted with cumulative concentrations of endothelin-1, and (3) contracted with the nitric oxide synthase inhibitor, N(G)-monomethyl-L-arginine. Furthermore, the release of prostacyclin by the IMA rings was directly measured during basal tone conditions and at the end of the various pharmacologic interventions. Histology of IMA rings was randomly performed., Results: The results obtained in these experiments showed that IMA rings harvested from hypertensive patients have the greatest impairment of endothelium-dependent response to relaxant and contracting stimuli (p < 0.01 versus nondiabetic-normotensive-normocholesterolemic tissues; p < 0.05 versus hypercholesterolemic and diabetic tissues) and prostacyclin release in normal and stimulated conditions. To a lesser extent, hypercholesterolemic and diabetic tissues show similar depression (diabetic > hypercholesterolemic) both of relaxation and prostacyclin production, with respect to nondiabetic-normotensive-normocholesterolemic specimens (p < 0.05). Histology findings (scanning electron microscopy) did not differ in multiple sections from vessel studies., Conclusions: Major cardiovascular risk factors affect the endothelium-dependent vasoactive homeostasis of human IMA differently. Depression of relaxation is highest in patients with a history of hypertension. These findings may be pertinent to early and long-term treatment of patients undergoing coronary artery bypass grafting.

Background: The aim of this study was to identify and stratify the most important preoperative factors for in-hospital death after surgery for type A aortic dissection., Methods: From January 1985 to June 1998, 108 patients underwent surgery for type A aortic dissection. 89.9% of the patients had an acute type A dissection (AD), whereas 11.1% had a chronic dissection (CD). Cardiac tamponade and shock occurred in 22% and 14.8% of the patients, respectively. The location of the primary intimal tear was in the ascending aorta in 71.2% of the cases, in the arch in 16.6% and in the descending aorta in 7.4%. Univariate and multivariate analyses were conducted to identify non-embolic variables independently correlated to in-hospital death. A predictive model of in-hospital mortality was then constructed by means of a mathematical method with the variables selected from logistic regression analysis., Results: The overall in-hospital mortality rate was 20.3% (22/108 patients), being 9% for CD and 21.6% for AD. Emergent procedures had an in-hospital mortality rate of 47.6%, whereas non-emergent operations had an in-hospital mortality rate of 13.7% (p<0.01). Univariate analysis revealed among 39 preoperative and operative variables, 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 selected as independent predicting variables (p<0.05), remote myocardial infarction (p=0.006), preoperative renal failure (p=0.032), shock (p=0.001), age >70 years (p=0.007). Finally, a probability table of death risk was obtained with the logistic regression coefficients. The lower death probability (10.6%) was calculated in absence of risk variables; the higher one in presence of all of them (79.7%). Between these extremes, a total of 64 combinations of death risk were obtained., Conclusions: Increasing age, shock, coronary artery disease and renal failure are variously associated to a high risk of in-hospital death after surgical correction of type A aortic dissection. This predictive model of death probability allows to collocate preoperatively patients with type A aortic dissection at different levels of risk for in-hospital death.

We define as Banking of the tissues all the procedures that include the finding, preparation, conservation and distribution of the homograft. The vascular homografts are taken and put into a solution of transportation at +4 degrees C and kept at this temperature till their arrival at the Bank. The following step is the dissection of the homograft which will have to be performed as quickly as possible at most 24 hours after the taking in conditions of maximum sterility. At the Italian Homograft Bank at Centro Cardiologico, the vascular homografts are kept at +4 degrees C for 96 hours on average with antibiotics. After a phase of sterilization at +4 degrees C the tissue is frozen according to a homogeneous and controlled thermic decrease and stored at -150 degrees C/-180 degrees C in fumes of liquid nitrogen till the moment of their employment allowing a long term conservation. The aim of all these procedures of cryopreservation is to keep the structural and functional integrity of cells and tissues. The thermic decrease of the tissues must occur so that to avoid all the damages of the cellular vitality and functionality and especially of the tissue structure in toto. In order to limitate these events some cryoprotector agents are employed because they reduce the concentration of the solutes, the cellular dehydration, the formation of micro-macro crystals. Another step to establish if the homograft is proper is the study of bacteriological and viral aspects. The viral screenings are performed on the donor's blood and the bacteriological tests are performed on the tissue and on the liquids. For each phase of the banking a series of information about the donor and about the tissues are recorded and filed both on paper and database so that to grant always a right conduct of the material.

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.

The aim of this study was to identify and stratify the most important nonembolic risk factors for stroke after coronary bypass grafting. From June 1994 to June 1997 a series of 1532 patients (pts) underwent isolated myocardial revascularization on cardiopulmonary bypass (CPB). A retrospective chart review selected 1417 pts in whom the presence of aortic calcification or left ventricular mural thrombi was not detectable by echocardiogram, angiogram, and intraoperative records. Univariate and multivariate analyses were conducted to identify nonembolic variables independently correlated to postoperative stroke. A predictive model of stroke probability was then constructed by means of a mathematic method with the variables selected from logistic regression analyses. The global incidence of stroke was 1.8%. Univariate analysis revealed that, among 29 preoperative and operative variables, age, vasculopathy, emergency operation, previous cerebrovascular accident (CVA), CPB, and aortic cross-clamping times were factors strongly associated with postoperative stroke (p < 0.01). A first logistic regression analysis (LRA) selected as independent predicting variables (p < 0.05) age [odds ratio (OR) 1.07/year], vasculopathy (OR 4), previous CVA (OR 7.2), CPB time (OR 1/year), and emergency operation (OR 4.2). In a second stepwise LRA, age and CPB time were subdivided into cohorts as follows: age 65 but < 75 years, >/= 75 years; CPB time 120 but < 180 minutes, >/= 180 minutes. Both age >/= 75 years (p = 0.024; OR 3.3) and CPB time >/= 180 minutes (p = 0.002; OR 4.2), were found to be predictors of postoperative neurologic damage. Finally, a probability table of stroke risk was obtained with the logistic regression coefficients. A lower stroke probability (0.7%) was calculated in the absence of risk variables and a higher one in the presence of all of them (83.3%). Between these extremes, a total of 158 combinations of stroke probabilities were obtained. We concluded that previous CVA, vasculopathy, emergency operation, and age > 75 years are variously associated with a high risk of nonembolic stroke after myocardial revascularization. A duration of CPB longer than 3 hours strongly increases the probability of neurologic damage in the presence of the aforementioned variables.

Background: This study was conducted to assess the impact of coronary bypass surgery (CABG) without cardiopulmonary bypass (CPB) on high-risk patients., Methods: From February 1997 to July 1998, 71 patients considered at high-risk underwent a CABG off-pump. Using the "Higgins score", eleven preoperative risk factors were identified and stratified in this group of patients. Among 1271 patients who underwent CABG with CPB in the same period, using a computer-based matched comparison, a second identical group of patients was selected according to the 11 risk variables and the number with coronary disease, so that complete preoperative matching included the year of operation, score index and coronary target. Moreover, among seven other preoperative variables that were not included in the matching comparison, the two groups differed only in mean age (64 +/- 10.9 vs 61.6 +/- 7.3 in groups off and on-pump, respectively, p < 0.05). Postoperative outcome and complications and blood requirement were compared. Myocardial cell injury and left ventricular performance were also assessed in the two groups., Results: The global incidence of neurologic complications in the off-pump group was significantly lower (9.8 vs 0%, in on and off-pump groups, respectively; p = 0.02). Patients undergoing CABG off-pump required blood far less often (% of transfused patients: 26.7% for the patients with CPB and 11.2% for the patients without CPB; p = 0.032). Three patients from the on-pump group (4.2%) had a perioperative myocardial infarction (AMI), versus 0% of the off-pump cases (p = ns). Postoperative atrial fibrillation accounted for 14.1% in off-pump patients and 30.9% in on-pump patients (p = 0.027). One patient in both groups (1.4%) suffered from postoperative heart failure. Mean ventilation time and ICU stay did not differ significantly between the two groups. However, hospital discharge occurred earlier in the off-pump group (9.3 +/- 3 vs 12.6 +/- 8, p = 0.007). In-hospital death occurred in one case from the on-pump group (1.4%) versus 0% of patients operated off-pump. CPK-MB release in patients without perioperative AMI was significantly lower in off-pump patients 6 and 12 hours after the operation (36.6 +/- 17 IU/l vs 69.8 +/- 23 IU/l after 6 hours, p < 0.05; and 36.7 +/- 19 IU/l vs 67.3 +/- 26 IU/l after 12 hours, p < 0.05, in off and on-pump groups, respectively) and LVSWI turned out to be better in off-pump patients 6 hours postoperatively (34.2 +/- 2 g*m/m2 vs 27.2 +/- 3 g*m/m2, p < 0.01)., Conclusions: CABG without CPB seems to be a promising technique for high-risk patients. It offers better neurologic and cardiac protection, shortens postoperative hospital stay and reduces the need for blood transfusion.

Background: The objective of this study was to analyse the impact of acute surgery for native aortic valve endocarditis and its influence on the long-term prognosis after surgery., Methods: A total of 161 patients underwent aortic valve replacement for native active aortic valve endocarditis (NAAVE) during a 29-year period, from 1967 to 1995 (age range: 10 to 72 years; mean 48 +/- 12). The main indication for surgery was progressive congestive heart failure (76%). Other indications were untreatable sepsis (27%), peripheral or central emboli (12%) and, from 1978, echocardiographic evidence of friable, pedunculated vegetations (3%). Streptococcal and staphylococcal infections predominated. Concomitant procedures were performed in 27% of the patients, including mitral and tricuspid valve surgery and coronary bypass procedures., Results: Operative mortality was 8% in the majority of cases caused by heart failure or multi-organ failure. Multivariate logistic regression analysis identified NYHA class IV to be an independent predictor for postoperative death. Long-term survival for discharged patients was 75% at 10 years and 58% at 15 years, with a mortality rate of 3.6%/patient/year. Cox regression analysis identified the year of operation, trivalvular endocarditis and staphylococcal infection as independent predictors of survival. At 10 and 15 years after aortic valve replacement, 91% and 84% of the patients, respectively, were free of recurrent endocarditis. The presence of an abscess cavity at first operation was found to be predictive of recurrent endocarditis., Conclusions: Valve replacement for NAAVE offers a good chance for a cure and satisfactory long-term survival. Improvements in pre- and per-operative management of the very ill patient, and the use of allograft valves are likely to further improve long-term results. Finally, the presence of staphylococcal endocarditis requires long-term postoperative antibiotic therapy.

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.

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.

We report a case of diffuse thinning of an inferior epigastric artery early after its implantation as a coronary free graft. This phenomenon showed reversibility at the 20-month angiographic follow-up in response to progression of the proximal lesion in the recipient coronary artery. Graft vasodilation in response to atrial pacing and nitroglycerin infusion at late angiography confirmed the vasomotor adaptability of this arterial conduit.

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.

Thirty-five consecutive patients with aortic arch aneurysm who required surgical reconstruction were operated on with the aid of extracorporeal circulation between February 1985 and December 1993. Nineteen patients (54.3%) were treated with hypothermic circulatory arrest (HCA) (Group A) and 16 (45.7%) (Group B) with HCA and selective cerebral perfusion (SCP) through the carotid arteries. Preoperative characteristics didn't show any significant differences between the two groups: mean age was 58.7 +/- 12 vs 62.1 +/- 7, p = ns, male sex 73.6% vs 75%, p = ns; atherosclerotic aneurysms were 57.8% vs 43.7%, p = ns; Type A dissections 42.2% vs 56.3%, p = ns and emergency operation were 68.4% vs 43.7%, p = ns in Groups A and B respectively. For SCP, blood was infused initially at a rate of 200-300 ml/min, maintaining the 30-40% of cerebral blood flow in normothermia, successively, with the aid of transcranial Doppler sonography (TDS) SCP-flow was improved to 500-1000 ml/min. The MHz pulsed TDS was used to measure the middle cerebral artery flow velocity in deep hypothermia before the arrest, in order to adjust the SCP flow during the HCA. In all patients we used open aortic anastomosis; in two cases an extraanatomical ascending-descending aorta was required, and in other two the "elephant trunk" technique was used in case of combined aortic arch and descending aneurysms. The HCA times were similar in the two groups 47.5 +/- 22 vs 47.7 +/- 78, p = ns. Early deaths occurred in 5 patients of the Group A (26.3%) and in 3 patients of the group B (18.7%), p = ns.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

It has been well established that the internal thoracic artery (ITA) is a good alternative to the saphenous vein as conduit for coronary artery bypass grafting because of superior early and late patency. Many surgeons now commonly use both ITAs for CABG and many have adopted complex grafting methods such as free ITA graft and sequential anastomosis; despite these techniques, it's not always possible to achieve complete revascularization with arterial conduits. More recently the right gastroepiploic artery (rGEA) and the inferior epigastric artery (IEA) have been used as alternative arterial conduits. The authors report the experience of a case of myocardial revascularization in a patient with angina not responsive to medical therapy, severe tri-vessel coronary artery disease, which had a previous total bilateral saphenectomy; the patient was also found to have a right fibrothorax. In the surgical strategy the authors considered that the bilateral use of mammary artery could have been the cause of the depressed respiratory function and that it was important to leave intact the left hemithorax; they therefore employed the rITA in the revascularization of the anterior descending (AD). To complete the revascularization they used the IEA for a marginal branch of the circumflex artery and the rGEA for the interventricular posterior artery, branch of the right coronary artery. In this fashion good early results were obtained with absence of perioperative complications with a good life expectancy.

Segments of human saphenous vein, internal mammary artery, right gastroepiploic artery, and inferior epigastric artery were incubated in vitro in Krebs-Henseleit solution and compared in terms of their capacity to generate and release into the medium 6-keto-prostaglandin F1 alpha (PGF1 alpha), the stable metabolite of prostacyclin. The four vascular conduits were also challenged with endothelin-1 (40 ng/mL), and accumulation of the lipidic material in the bathing fluid was also studied. The results obtained show clearly that under both normal and endothelin-1-stimulated conditions, the four vascular segments generate a substantial amount of 6-keto-PGF1 alpha. Multiple-comparisons analysis of the results indicates that the rank order in producing 6-keto-PGF1 alpha is as follows: inferior epigastric artery > internal mammary artery > right gastroepiploic artery > saphenous vein (p < 0.01). A similar order of potency was obtained in vascular conduits stimulated with endothelin-1. The rate of formation of immunoreactive 6-keto-PGF1 alpha under both normal and stimulated conditions by the inferior epigastric artery (normal, 301 +/- 8 pg/mg of tissue; stimulated, 519 +/- 15 pg/mg of tissue) was at 10 minutes more than 2 times (p < 0.01) that of the saphenous vein and about 1.5 times (p < 0.01) that of the right gastroepiploic artery.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

Twenty-five patients underwent early and elective valve replacement for infective endocarditis during a 5-year period between April 1985 and March 1991. Indications for urgent surgical intervention performed at a mean 32 (range 6-47) days after admission were intractable heart failure, systemic emboli, septic multiorgan failure and the presence of vegetations. Indication for elective surgery was persistent (mean 42 (range 17-56) days) infection after appropriate antibiotic therapy. Twenty patients (80%) had a native valve endocarditis; five (20%) had prosthetic valve involvement. A total of 30 valvular prostheses were implanted: 22 (73.3%) were aortic (21 mechanical and one biological); eight (26.7%) were mitral (all mechanical). All unstable patients referred were treated before surgery in the intensive care unit and subjected to blood ultrafiltration to restore satisfactory circulatory parameters. No patient underwent cardiac catheterization; all patients were operated upon on the basis of echocardiographic data alone. One patient (4%) died during hospitalization; two (8%) died later at 48 and 12 months after the first intervention. The reoperation rate was 12%. After a mean follow-up of 49 (range 1-71) months, 21 of the survivors (95%) were in New York Heart Association functional class I or II; the actuarial 5-year survival rate was 87%. Precise preoperative assessment of early operative indications and timely association of medical therapy in unstable patients could represent a step forward in the treatment of acute infective endocarditis.

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.

Two successful cases of staged replacement of multiple aneurysms of the thoracic aorta using the 'elephant trunk' technique are described. The management of both cases is discussed.

When complete revascularization can not be obtained with the internal mammary artery and saphenous veins, the inferior epigastric artery may be an excellent alternative conduit. We describe our experience with this conduit, review the anatomy of this artery, and present the evolution of our harvesting technique through a pararettal approach. Proximal anastomoses were made first with the aid of an oval cuff of the common femoral artery (5 cases, Group A). Two patients (40%) of this group studied postoperatively revealed a graft occlusion. In the last 13 cases (Group B) we tailored the proximal anastomoses directly to the aorta. All patients studied postoperatively showed patent inferior epigastric artery grafts. There were no hernias and no deaths. Inferior epigastric artery can be considered a good alternative conduit in myocardial revascularization.