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Biomedical subjects

Gianfederico Possati

Publications and source records attributed to Gianfederico Possati.

At least 19 recordsLinked to original sources
PubMed2006

Repeat valvular operations: bench optimization of conventional surgery.

BACKGROUND: Repeat heart valve operations have become a quite common procedure. We reviewed our experience with reoperative valvular surgery during a 6-year period to assess the risk factors affecting in-hospital mortality and medium-term survival. METHODS: A series of 316 redo procedures performed on a total of 290 patients in the period between 1997 and 2002 at our institution was retrospectively analyzed. Univariate and multivariable analyses were performed. RESULTS: In-hospital mortality was 3.8%; overall mortality at the end of a 30-month follow-up was 9.3%. We identified advanced New York Heart Association class, advanced age, depressed ejection fraction, emergent or urgent presentation, impairment of renal function, and involvement of tricuspid valve as predictors of mortality. In contrast, duration of cardiopulmonary bypass and multiple valve procedure were not associated with increased short-term risk. CONCLUSIONS: The present study is characterized by particular attention in reducing confounding variables and biases correlated to heterogeneities. The main determinants of mortality are related to the degree of patients' illness rather than to inherent technical factors of reoperations. Although highest-risk individuals (previous coronary artery bypass grafting or coexistence of aortic aneurysm) were excluded from the study, our data suggest that patients undergoing isolated redo valvular procedures now face operative risks that are comparable to primary intervention.

Cardiac Surgical Procedures↗
PubMed2006

Patients with in-stent restenosis have an increased risk of mid-term venous graft failure.

BACKGROUND: This study was designed to evaluate if patients in whom in-stent restenosis developed had an higher risk of early venous graft failure compared with normal patients. METHODS: The study cohort comprised 120 patients (60 with previous in-stent restenosis and 60 controls) who received a total of 165 complementary venous grafts on the circumflex or right coronary artery system (84 in the restenosis group and 81 in the control group). All patients were prospectively followed-up and underwent reangiography at 5-years follow-up. RESULTS: In the restenosis group, 28 venous grafts (33.%) were perfectly patent, 10 showed major irregularities, and 46 were occluded. In the control patients, 50 grafts (61.7%) were perfectly patent (p < 0.001 compared with the restenosis series), 12 showed major irregularities (p = .74), and 19 were occluded (p < 0.0001). In contrast, the 5-year outcome of internal thoracic artery grafts was not affected by history of in-stent restenosis. CONCLUSIONS: Patients who developed in-stent restenosis have an higher risk of early venous graft failure compared with the control patients. Arterial grafts should probably be preferred in these patients.

Aged↗
PubMed2005

Ten-year Echo-Doppler evaluation of forearm circulation following radial artery removal for coronary artery bypass grafting.

OBJECTIVE: To investigate the chronic consequences of radial artery removal for coronary artery bypass surgery on the forearm circulation. METHODS: Thirty-nine patients submitted to radial artery removal for coronary artery bypass were submitted to serial Echo-Doppler evaluation of the flow and morphology of the forearm arteries until 10 years follow-up. RESULTS: The peak systolic velocity of the ulnar artery of the operated side was significantly higher than the control site. The intima-media thickness of the ulnar artery was always significantly higher on the operated side, and this difference reached statistical significance at 10 years follow-up. There was a significantly higher prevalence of atherosclerotic plaques in the ulnar artery (UA) of the operated versus control arm (11/39 vs 0/39; p=0.005). CONCLUSIONS: Radial artery removal for coronary artery bypass surgery leads to a chronic increase in ulnar flow accompanied by increased intima-media thickness and accelerated atherosclerotic disease. These findings may have potentially important implications for surgical indications and patients management.

Blood Flow Velocity↗
PubMed2005

Implantation in coronary circulation induces morphofunctional transformation of radial grafts from muscular to elastomuscular.

BACKGROUND: The purpose of this research was to investigate the in vivo morphofunctional changes induced in the radial artery (RA) by its use as coronary artery bypass conduit by comparing the morphological features and vasoreactivity of the native RA versus the coronary RA graft in the same patient. METHODS AND RESULTS: Ten years after surgery, 10 patients were submitted to intravascular ultrasound examination of the RA graft of the controlateral (in situ) RA and of the internal thoracic artery (ITA) graft and to vasoactive challenges with acetylcholine and serotonin. Quantitative angiographic assessment showed that the mean diameter of the RA coronary grafts was significantly larger than that of the in situ RA and of the ITA (2.89+/-0.40 mm RA grafts, 2.14+/-0.52 mm in situ RA, 2.25+/-0.53 mm ITA grafts; P<0.001). The in situ RA demonstrated a typical muscular architecture, whereas RA coronary grafts showed a clear reduction of the thickness of the medial layer and had a less well-defined muscular component of the media with interposition of elastic tissue. Serotonin endovascular infusion elicited a strong spastic reaction in in situ RAs; the same challenge induced only moderate constriction in RA and ITA coronary grafts. CONCLUSIONS: Implantation in the coronary circulation leads to major anatomic and vasoreactive modifications of the RAs that tend to lose the morphofunctional features of a muscular conduit and assume those of an elastomuscular artery, such as the ITA.

Acetylcholine↗
PubMed2005

Arterial versus venous bypass grafts in patients with in-stent restenosis.

BACKGROUND: In patients who develop in-stent restenosis, successful revascularization can be difficult to achieve using percutaneous methods. This study was designed to verify the surgical results in this setting and to evaluate the potential beneficial role of arterial bypass conduits. METHODS AND RESULTS: Sixty consecutive coronary artery bypass patients with previous in-stent restenosis and 60 control cases were randomly assigned to receive an arterial conduit (either right internal thoracic or radial artery; study group) or a great saphenous vein graft (control group) on the first obtuse marginal artery to complete the surgical revascularization procedure. At a mean follow-up of 52+/-11 months, patients were reassessed clinically and by angiography. Freedom from clinical and instrumental evidence of ischemia recurrence was found in 19 of 60 subjects in the study group versus 45 of 60 in the control series (P=0.01). The results of the arterial grafts were excellent in both the study and control groups (right internal thoracic artery patency rate, 19 of 20 for both, and radial artery patency rate, 20 of 20 versus 19 of 20; P=0.99). Saphenous vein grafts showed lower patency rate than arterial grafts in both series and had extremely high failure rate in the study group (patency rate, 10 of 20 in the study group versus 18 of 20 in the control group; P=0.001). Use of venous graft was an independent predictor of failure in the study group, whereas hypercholesterolemia was associated with graft failure in both series. CONCLUSIONS: Venous grafts have an high incidence of failure among cases who previously developed in-stent restenosis, whereas the use of arterial conduits can improve the angiographic and clinical results. Arterial grafts should probably be the first surgical choice in this patient population.

Aged↗
PubMed2005

Managing latex-free mitral valve replacement.

The management of cardiac surgery patients with latex allergy can be challenging. We describe successful mitral valve replacement in a latex-allergic patient using an integrated multidisciplinary approach. We also provide a list of some available latex-free products or latex-free alternatives.

Adult↗
PubMed2005

Different profiles of patients who require dialysis after cardiac surgery.

BACKGROUND: This study was aimed at evaluating the determinants of postoperative dialysis-requiring acute renal failure and at identifying eventual correlations between the different etiologic mechanisms and postoperative prognosis. METHODS: We evaluated the preoperative and intraoperative features of the 69 out of 6,542 consecutive cardiac surgery patients who developed postoperative dialysis-requiring acute renal failure at our Institution during a 10-year period. RESULTS: Age, valvular and aortic surgery, hypertension, extracardiac vasculopathy, timing of surgery, cardiopulmonary bypass time, and preoperative creatinine level greater than 2.0 mg/dL were identified as predictors by multivariate analysis. In a second analysis, patients were divided in two groups according to the preoperative creatinine level: group A (preoperative creatinine 2.0 mg/dL or less; 38 cases) and group B (preoperative creatinine 2.1 mg/dL or more; 31 cases). The two groups significantly differed in preoperative and intraoperative characteristics and in postoperative outcome: group A patients were younger, had a lower incidence of cardiac and vascular risk factors and comorbidities, were mainly operated on urgent or emergent basis for valvular or aortic pathologies, had longer cardiopulmonary bypass and cross-clamp time, and worse in-hospital outcome but higher midterm survival. Group B patients were older, had a higher prevalence of comorbidities, required more often in-hospital or after-discharge dialysis, had lower in-hospital mortality, but reduced midterm survival. CONCLUSIONS: Postoperative dialysis-requiring acute renal failure can be the result of two different pathophysiological pathways: complicated perioperative course due to urgent-emergent surgery or main intraoperative technical complications in patients with preoperative normal renal function and uncomplicated perioperative course associated with reduced preoperative kidney function. The two patient groups significantly differ in baseline preoperative features, as well as in in-hospital and in midterm outcome.

Acute Kidney Injury↗
PubMed2005

Midterm angiographic patency and vasoreactive profile of proximal versus distal radial artery grafts.

BACKGROUND: No data are available on the different angiographic results and the in vivo vasoreactivity of radial artery (RA) grafts obtained from different parts of the conduit, although it is known that the distal segment of the artery has a more pronounced muscular component. This study was conceived to evaluate the angiographic patency and tendency to spasm of proximal versus distal RA grafts. METHODS: In 29 patients, at the time of surgical myocardial revascularization, the radial artery was divided into two separate conduits, so that these patients received a total of 58 radial grafts (29 from the proximal and 29 from the distal portion of the artery). All cases were submitted to midterm angiography and vasoactive challenges to verify angiographic patency and vasoreactive profile. RESULTS: Radial artery patency rate was 28 of 29 for both groups. Nine cases of string sign were reported, all in the distal series (p = 0.001). The perfect patency rate of distal grafts was markedly lower than that of proximal grafts (19 of 29 versus 27 of 29; p = 0.02). Vasoactive challenges testified to a higher vasospastic attitude of distal grafts. CONCLUSIONS: Radial artery grafts obtained from the distal portion of the artery have a higher vasospastic tendency, greater incidence of string sign, and lower midterm perfect patency rate than graft taken from the more proximal part of the artery. The proximal part of the RA should be preferred for use as a conduit for surgical myocardial revascularization.

Angiography↗
PubMed2005

Harmonic scalpel reduces bleeding and postoperative complications in redo cardiac surgery.

BACKGROUND: Intraoperative and postoperative bleeding and injuries to cardiac structures are among the main determinants of complications and hospital and intensive care unit stay after cardiac reinterventions. The harmonic scalpel has been reported to achieve optimal tissue dissection with little blood loss. The present retrospective work was performed to evaluate the safety and usefulness of this device in redo cardiac surgery. METHODS: Ninety-six redo cardiac surgery patients were operated on with the use of harmonic scalpel, and 105 redo patients operated on by traditional electrocautery and scissors were selected from our database and served as controls. Intraoperative and postoperative data of the two groups were collected and compared. Univariate and multiple logistic regression analyses were performed for identification of factors associated with death and with major and minor complications in the overall study population and in both groups, separately. RESULTS: Although mortality and major postoperative morbidity were comparable in the two groups, harmonic scalpel patients presented markedly reduced postoperative bleeding, lower incidence of minor complications, cardiac injuries, major arrhythmias, and need for transfusions. Operative time and mean intensive care unit stay were shorter. Use of ultrascissor was found to be a protective factor against minor morbidity at multivariate analysis. CONCLUSIONS: Our data suggest that harmonic scalpel is safe and is associated with better in-hospital outcome and lower postoperative blood loss in redo cardiac surgery.

Aged↗
PubMed2005

Is postoperative calcium channel blocker therapy needed in patients with radial artery grafts?

BACKGROUND: Chronic calcium channel blocker therapy has traditionally been considered necessary in patients carrying a radial artery graft, even in the absence of objective data to support it. This report was conceived to evaluate the angiographic and clinical effects of calcium channel blocker therapy during the first postoperative year. PATIENTS AND RESULTS: A total of 100 consecutive patients who received a radial artery graft at our institution were randomly assigned to receive (n = 53) or not receive (n = 47) calcium channel blocker therapy with oral diltiazem 120 mg/daily started in the early postoperative period. At 1-year follow-up, all patients were reassessed clinically and by Tl 201 myocardial scintigraphy, and 83 of them underwent control angiography. In 12 cases we also evaluated the response of the radial artery to the endovascular infusion of serotonin. No difference in terms of clinical outcome, scintigraphic results, and patency rate was found between patients who received or did not receive calcium channel blocker therapy. Endovascular serotonin infusion evoked an evident spastic reaction of radial artery grafts, not attenuated by calcium channel blocker therapy. CONCLUSION: Calcium channel blocker therapy started immediately after surgery and continued for the first postoperative year does not affect radial artery graft patency and clinical and scintigraphic outcomes. On the basis of these data, the prophylactic use of calcium channel blocker therapy in patients with radial artery grafts seems unsubstantiated.

Aged↗
PubMed2005

Chronic compensatory increase in ulnar flow and accelerated atherosclerosis after radial artery removal for coronary artery bypass.

BACKGROUND: Only scant information is available on the chronic consequences of radial artery removal for coronary artery bypass surgery on forearm circulation. METHODS: Twenty-five patients submitted to radial artery removal for coronary artery bypass were submitted to serial Doppler echocardiographic evaluation of the flow and morphology of the forearm arteries. RESULTS: The peak systolic velocity of the ulnar artery of the operated side was significantly higher than that of the control site. The intimal-medial thickness of the ulnar artery was always significantly higher on the operated side, and this difference reached statistical significance at 10 years' follow-up. There was a significantly higher prevalence of atherosclerotic plaques in the ulnar artery of the operated versus control arm (7/25 vs 0/25, P = .03). CONCLUSION: Radial artery removal for coronary artery bypass surgery leads to a chronic increase in ulnar flow accompanied by increased intimal-medial thickness and accelerated atherosclerotic disease. These findings might have potentially important implications for surgical indications and patient management.

Arteriosclerosis↗
PubMed2004

Survival after aortic valve replacement for aortic stenosis: does left ventricular mass regression have a clinical correlate?

AIM: The effects of post-operative left ventricular mass regression (LVMR) on clinical outcome after aortic valve surgery remains to be established. This study was intended to establish the impact of patient characteristics on post-operative survival in patients referred for aortic valve replacement (AVR), with particular regard to LVMR. METHODS AND RESULTS: Two hundred and sixty consecutive cases submitted to aortic valve replacement for valvular stenosis were prospectively followed for a mean of 28+/-9 months. Baseline, characteristics and extent of LVMR were tested for association with survival by uni- and multivariable analysis. Ten deaths occurred during hospital stay and 52 during out-of-hospital follow-up. Mean left ventricular mass decreased from 190+/-43 to 158+/-70 g/m2 (P<0.001). Older age, advanced functional class, hypertension, reduced left ventricle ejection fraction, and high pre-operative left ventricular mass index were associated with reduced survival. Overall the extent of LVMR did not influence the clinical results, while only early (<6 months) LVMR was weakly associated with mid-term outcome. CONCLUSION: Survival after aortic valve surgery is mainly determined by the pre-operative functional cardiac and systemic status. The extent of LVMR does not correlate with clinical outcome, whereas aggressive treatment of hypertension may improve post-operative survival.

Aged↗
PubMed2004

Skeletonization does not influence internal thoracic artery innervation.

BACKGROUND: This study was designed to compare the effect of surgical harvesting on internal thoracic artery innervation and to assess the eventual presence of denervation supersensitivity in skeletonized grafts. METHODS: Nineteen patients who underwent primary isolated coronary artery bypass grafting were randomly assigned to receive a skeletonized (n = 9) or pedicled (n = 10) internal thoracic artery graft. Immunohistochemical nerve localization using anti-S-100 protein, anti-160-kd neurofilament polypeptide and anti-tyrosine hydroxylase antibodies was performed on distal specimens of arteries to study vascular innervation. Moreover, endovascular vasoactive challenges using serotonin and methylergometrine were performed at early angiographic control to evaluate the eventual presence of denervation supersensitivity. RESULTS: Quantitative analysis of immunohistochemical specimens revealed lack of difference in the number of positive cells between skeletonized and pedicled arteries for all the antibodies used. No difference in the reaction to serotonin and methylergometrine was found between skeletonized and pedicled arteries. CONCLUSIONS: Skeletonization does not influence internal thoracic artery innervation.

Aged↗
PubMed2004

Effect of target artery location and severity of stenosis on mid-term patency of aorta-anastomosed vs. internal thoracic artery-anastomosed radial artery grafts.

OBJECTIVE: To verify the effect of location and severity of stenosis of the target coronary artery (TCA) on mid-term patency of aorta-anastomosed vs. internal thoracic artery (ITA)-anastomosed radial artery (RA) graft. METHODS: During a 3-year period 228 consecutive patients received an RA graft at our institution. In 131 cases the RA was anastomosed to the aorta whereas in 97 the proximal anastomosis was performed on a mammary graft. The two groups were comparable in terms of preoperative variables and TCA characteristics. At a mean follow-up of 6.5 years 128 cases of the aorta-anastomosed and 95 of the mammary-anastomosed group were submitted to control angiography. RESULTS: Mid-term patency and perfect patency rates were 92.1 and 89.8% (118/128 and 115/128) for aorta-anastomosed RA vs. 86.3 and 84.2% for mammary-anastomosed grafts (82/95 and 80/95; P=0.81 and 0.82). The location of TCA did not influence graft patency in the two groups. The severity of the TCA stenosis strongly influenced graft patency in both groups but the threshold for failure was clearly higher in the mammary-anastomosed group. CONCLUSIONS: ITA-anastomosed RA grafts are more vulnerable to the detrimental effect of chronic native competitive flow and should be used only for target vessel with subocclusive stenosis. The location of the distal anastomosis does not influence long-term RA patency.

Aorta↗
PubMed2004

Myocardial ischemia, stunning, inflammation, and apoptosis during cardiac surgery: a review of evidence.

Cardiac surgery (CS), in particular cardiopulmonary bypass and cardioplegia, have been reported to trigger myocardial inflammation and apoptosis. This surgery-related inflammatory reaction appears to be of extreme complexity with regard to its molecular, cellular and tissue mechanisms. Both experimental and clinical studies have ascertained the role of several hormonal mediators, mitochondria, cardioplegia and extracorporeal circulation temperature, apoptosis and even genetic modulators of damage. However, the correlations between these factors in vivo and post-surgery outcome and prognosis have not yet been systematically investigated. In animal models of myocardial cardioplegia and/or ischemia-reperfusion, experimental drugs such as antioxidants have been documented to provide amelioration of post-intervention cardiac performance and reduction of apoptosis suggesting the possibility of new therapeutic strategies. However, these findings have been only partially confirmed in humans. Moreover, markers for the differential detection of early and late phases of apoptosis are subjects of intense investigations. This review will provide an overview of the major studies about the link between ischemia, myocardial inflammation and apoptosis during and after CS, with particular regard to the markers and methods for apoptosis detection.

Apoptosis↗
PubMed2004

Composite Y internal thoracic artery-saphenous vein grafts: short-term angiographic results and vasoreactive profile.

BACKGROUND: The angiographic patency of composite Y internal thoracic artery-saphenous vein grafts has not been investigated in detail. METHODS: Twenty-five patients who received composite Y internal thoracic artery-saphenous vein grafts had control angiography and vasoactive challenges with serotonin, acetylcholine, and isosorbide dinitrate at a mean of 2.5 +/- 1.2 years after surgery. RESULTS: The perfect patency rate of composite Y internal thoracic artery-saphenous vein grafts was 72% (18/25). The distal portion of the internal thoracic artery was stringed in 4 patients and occluded in 2. The saphenous branch of the composite Y internal thoracic artery-saphenous vein grafts was found patent in all patients except 1. No failures were reported in the proximal tract of the internal thoracic artery. The distal tract of the internal thoracic artery showed reduced capacity of endothelium-mediated relaxation. CONCLUSION: The short-term patency of composite Y internal thoracic artery-saphenous vein grafts is suboptimal and markedly influenced by distal runoff and native flow competition.

Aged↗