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Biomedical subjects

Luca Dainese

Publications and source records attributed to Luca Dainese.

15 recordsLinked to original sources
PubMed2007

Resection and end-to-end anastomosis for ascending aortic aneurysms associated with a bicuspid valve: case reports.

Ascending aortic aneurysms associated with a bicuspid valve are generally treated by replacement with a tubular graft because the aortic wall is claimed to be genetically pathological. We describe 9 cases in which patients with an ascending aortic aneurysm and an associated diseased bicuspid valve underwent aneurysmal resection and end-to-end anastomosis. This technique permitted us to remove the entire aneurysmal wall, avoiding graft interposition.

Adult↗
PubMed2006

17Beta-estradiol effects on human coronaries and grafts employed in myocardial revascularization: a preliminary study.

BACKGROUND: This study was undertaken to compare the in vitro effects of 17beta-estradiol on human epicardial coronary arteries, resistance coronary arteries and on arterial vessels usually employed as grafts in surgical myocardial revascularization. METHODS: Coronary artery rings (descending coronary artery, right coronary artery, circumflex coronary artery, first septal branch) and arterial graft rings (internal thoracic artery, gastro-epiploic artery) obtained from human heart donors with heart not suitable to cardiac transplantation were connected to force transducer for isometric force recording. Precontracted specimens with and without endothelium were exposed to increasing concentration of 17beta-estradiol (3-30-300-3000 nmol/l) and to vehicle (0.1% v/v ethanol). We also evaluated the effects of 17beta-estradiol on vessels before and 20 minutes after exposure to L-monomethyl-arginine and indomethacin. RESULTS: 17beta-estradiol induced a significant relaxation in all precontracted vessels (mean maximum effect: 78,6% +/- 8,5). This effect was not different among the different rings and was not related to the presence of endothelium. N-monomethyl-L-arginine and indomethacin did not modify 17beta-estradiol relaxant effect. CONCLUSION: The vasodilator action of the 17beta-estradiol is similar on coronary arteries, resistance coronary arteries and arterial vessels usually employed as grafts in myocardial revascularization.

Journal Article↗
PubMed2006

Reduction ascending aortoplasty: midterm follow-up and predictors of redilatation.

BACKGROUND: Reduction ascending aortoplasty is an alternative procedure to the replacement of the ascending aorta in case of ascending aorta aneurysm without aortic root involvement. This study was designed to evaluate the midterm follow-up of aortoplasty and to determine predictors of redilatation. METHODS: From January 1, 1998, to April 30, 2005, 68 patients with dilatation of the ascending aorta underwent unsupported reduction aortoplasty in combination with other cardiac procedures. All patients underwent associated surgical procedures. Sixty patients (88.2%) underwent associated aortic valve replacement. Cumulative follow-up time was 191.4 patient-years and was 100% complete. Median follow-up time was 2.5 years, and mean follow-up time was 2.9 +/- 1.7 years (range, 0.4 to 6.3 years). RESULTS: The overall perioperative mortality rate was 1.5%. Overall survival estimates at 3 and 6 years were 93.3% +/- 4.5% and 89.3% +/- 5.9%, respectively. The actuarial freedom from cardiac-related death at 3 and 6 years was 100% and 95.7% +/- 4.3%, respectively. Ascending aorta redilatation occurred in 5 patients (7.5%). The actuarial freedom from redilatation at 3 and 6 years was 97.7% +/- 2.3% and 79.8% +/- 8.4%, respectively. The actuarial freedom from reoperation at 3 and 6 years was 100% and 86.3% +/- 7.5%, respectively. Only preoperative diameter was a significant predictor of redilatation using multivariate stepwise logistic regression analysis. CONCLUSIONS: Unsupported reduction aortoplasty is a safe and effective technique with low mortality, low morbidity, and rare late complications for selected chronic aneurysm of the ascending aorta with diameter less than 55 mm.

Adult↗
PubMed2006

Left common carotid artery as inflow site in coronary artery bypass grafting.

Porcelain aorta is associated to significantly increased risk of atheromatous embolization in patients who undergo cardiac surgery. We described three cases in which coronary artery bypass grafting was performed off-pump and the saphenous vein graft was anastomosed proximally to the left common carotid artery. This technique permitted avoidance of ascending aortic manipulation and reduce the risk of atheromatous embolization.

Aged↗
PubMed2006

Effect of cryopreservation techniques on aortic valve glycosaminoglycans.

This study was designed to evaluate the effect of cryopreservation on the glycosaminoglycan (GAG) content of the aortic allografts. Twenty-one porcine aortic valves were obtained. Five aortic roots were immediately analyzed without cryopreservation, eight were cryopreserved in closed leaflet position, and eight in open leaflet position. The groups were compared in terms of GAG concentration and subclass proportion in three different zones including the aortic root wall, the commissures, and the leaflets. GAG content at the commissures was significantly lower in the closed leaflet group than in the other groups (P = 0.001). The electrophoretic analysis did not show any significant difference in the zonal distribution of GAG classes between groups. Quantitative analysis in various aortic valve zones suggests that cryopreservation can alter the GAG content. Cryopreservation of the aortic valve in an open leaflet position can preserve the matrix more efficiently and might prolong the durability of the aortic allograft.

Animals↗
PubMed2006

[Off-pump coronary bypass surgery: pros and cons].

Off-pump coronary artery bypass surgery is a well established surgical option for patients candidate to coronary artery bypass. Current evidence suggests that there are no differences between off-pump and on-pump coronary surgery in terms of major perioperative outcomes such as perioperative mortality, myocardial infarction, stroke, and renal failure, whereas off-pump coronary surgery seems to reduce some minor complications like atrial fibrillation, transfusion requirements, and postoperative hospital stay. However, some recent papers suggest that graft patency may be lower for grafts performed with the off-pump technique. In this paper we review current knowledge about pros and cons of off-pump and on-pump coronary bypass surgery.

Atrial Fibrillation↗
PubMed2005

Preoperative assessment of the radial artery for coronary artery bypass grafting: is the clinical Allen test adequate?

BACKGROUND: The clinical Allen test (AT) is widely adopted as the only preoperative assessment of the hand collateral circulation before radial artery (RA) harvest as a coronary artery bypass graft. Nevertheless, in some cases it may be misleading because of clinically undetectable anatomic anomalies of the forearm arteries. METHODS: We evaluated the nondominant forearm arterial circulation by echo color Doppler (ECD) technique and by performing static and dynamic tests such as the AT, snuffbox test (SBT), and palmar arch test (PAT) in 150 patients who underwent elective coronary artery revascularization with a RA graft. RESULTS: Although the clinical AT was normal in all patients, in 8 patients (5.3%) preoperative ECD AT, SBT, and PAT did contraindicate RA harvesting. We did not harvest the RA in these patients. In the remaining 142 patients the RA was harvested. We did not observe any case of postoperative forearm or hand ischemia. We examined the blood flow to the hand in all patients at both 5 days and 24 months after surgery. In all patients ECD showed adequate hand perfusion and a significant increase of the peak flow velocity in the ulnar artery at both follow-up times. CONCLUSIONS: The clinical AT may be not sufficient to assess the hand collateral flow and the quality of the RA as a coronary artery bypass graft in at least 5% of patients. The ECD technique, performed during static and dynamic tests, does offer a safer and more objective preoperative noninvasive evaluation and it may have an important role also from the medicolegal point of view.

Blood Flow Velocity↗
PubMed2005

Long-term results after aortic valve replacement with the Bravo 400 stentless xenograft.

BACKGROUND: This study was undertaken to evaluate the long-term clinical and echocardiographic outcome after aortic valve replacement with the Bravo Cardiovascular Model 400 stentless xenograft. METHODS: Between February 1992 and January 1994, 67 patients underwent aortic valve replacement with the Bravo 400 bioprosthesis. The valvular pathology was aortic stenosis in 36 patients (53.7%), aortic insufficiency in 17 patients (25.4%), and mixed lesion in 14 patients (20.9%). Mean follow-up time was 9.8 +/- 2.73 years and median follow-up time was 11 years. Cumulative follow-up time was 659 patients-years and was 94% complete. RESULTS: No early deaths were observed. Overall survival estimates at 11 years were 74.71% +/- 5.47%. The actuarial freedom from valve-related death at 11 years was 91.04% +/- 3.84%; from cardiac-related death at 11 years it was 87.95% +/- 4.29%; and from noncardiac death at 11 years it was 85.14% +/- 4.58%. Eleven-year Kaplan-Meier survival of patients younger than 65 years was 90.91% +/- 6.13% versus 66.08% +/- 7.38% for older patients (p = 0.0307, log-rank test). The actuarial freedom from all valve-related morbidity and mortality at 11 years was 80.3% +/- 5.4%. The mean transvalvular gradient decreased significantly after aortic valve replacement with a corresponding increase in effective orifice area. Left ventricular mass index at 10-year follow-up was 68.5% of the preoperative value. CONCLUSIONS: The Bravo Cardiovascular Model 400 stentless xenograft has provided good clinical and hemodynamic results up until 11 years of follow-up.

Adult↗
PubMed2004

Six-year monitoring of the donor-specific immune response to cryopreserved aortic allograft valves: implications with valve dysfunction.

BACKGROUND: The immune rejection has been anticipated as one of the major causes of allograft aortic valve (AAV) degeneration. The purpose of this study was to prospectively serially measure the magnitude and evolution of the recipient anti-HLA class I antibody response up to 6 years from AAV implant and to correlate serologic data with valve performance by means of a concurrent echocardiographic survey. METHODS: Cryopreserved AAVs were obtained from multiorgan HLA-typed donors. Nineteen patients younger than 50 years (mean age, 43.3 +/- 8 years) were prospectively studied. After successful surgery, all AAV recipient underwent at 3 and 6 months and each year postoperatively (mean follow-up, 71.9 months) concomitant serum sample collection and two-dimensional transthoracic echocardiography. The presence of anti-HLA antibodies was tested against a panel of lymphocytes obtained from 30 blood donors. RESULTS: Progressive structural valve deterioration was seen in 6 patients (31.5%) of whom 4 (21%) were reoperated. All pretransplant recipients sera were panel-reactive antibody negative. Seventeen patients (89.4%) demonstrated significant panel-reactive antibody levels, which peaked at 6 months postoperatively, declined from 6 to 24 months, and slowly decreased afterward. In 14 of 19 cases (73.6%) donor-specific HLA antibodies were identified. A strong immunization (6-year persistence of panel-reactive antibody > 70% and peak panel-reactive antibody > 80%) was detected in 31.5% and 36.8% of recipients, respectively. Strong immunization was found to be significantly associated with progressive structural deterioration. CONCLUSIONS: The immune reaction after cryopreserved AAV implantation is a peculiar long-lasting response occurring in the majority of recipients younger than 50 years of age. An association between a sustained and pronounced immunization and an aggressive AAV degeneration was observed.

Adolescent↗
PubMed2003

Aortic valve: do its nervous and contractile elements have any role?

Recent knowledge on aortic valve physiology and its cellular and ultrastructural characteristics lead us to believe that the opening and closing mechanism is not only the result of the different pressures between the aorta and left ventricle but it is also a function of the interaction between elastic forces acting on a complex structure such as the valve. The latter consists of cells with muscular properties and of some elements capable of dynamically modifying their properties. These cells, which can regenerate themselves, seem to be closely related to nerve endings whose exact function at the valvular level is yet to be defined. The aim of this paper was to review the most recent literature on the aortic valve nervous and ultrastructural properties as they are related to the physiological and pathophysiological patterns.

Aorta↗
PubMed2002

Acute effects of 17beta-estradiol on left internal mammary graft after coronary artery bypass grafting.

BACKGROUND: Vasospasm of arterial conduits used for coronary surgical procedures is an important cause of postoperative graft failure. Mounting experimental evidence suggests that estrogen reverses acetylcholine-induced vasospasm of the coronary arteries in animals and humans. Estrogen also affects endothelium-derived constrictor factors. We therefore investigated the in vivo vasomotor responses to transdermal 17beta-estradiol of the left internal mammary artery (LIMA) grafted on the anterior descending coronary artery. METHODS: We studied 20 women, mean age of 62 +/- 7.2 years (range, 48 to 73 years), who had undergone cardiopulmonary bypass for coronary artery bypass grafting. They received transdermal 17beta-estradiol on the fifth day after operation. The diameter, cross-sectional area, and blood flow of the LIMA graft were measured by transthoracic color Doppler echography before (basal values) and after the transdermal administration of 50 microg of 17beta-estradiol (control). RESULTS: LIMA graft vasodilation after the administration of 17beta-estradiol was observed. A significant increase in diameter (2.06 +/- 0.4 mm versus 2.37 +/- 0.28 mm; p = 0.035) and cross-sectional area (3.45 +/- 1. 2 mm2 versus 4.24 +/- 1 mm2; p = 0.039) was registered. The LIMA graft mean flow increased by 49% (44.76 +/- 27.19 mL/min versus 56.62 +/- 27.69 mL/min), but this increase was not statistically significant (p = 0.06). CONCLUSIONS: The acute postoperative transdermal administration of 17beta-estradiol induced a significant increase of LIMA graft diameter and cross-sectional area in postmenopausal women who underwent coronary artery bypass grafting. The LIMA graft vasodilation was also associated with an improvement in LIMA blood flow.

Administration, Cutaneous↗