Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Prosthesis Coloring”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed2001

Outcome and follow-up of aortic valve replacement with the freestyle stentless bioprosthesis.

BACKGROUND: The aim of this study was to determine the morbidity, mortality, and hemodynamics after implantation of the Freestyle stentless bioprosthesis in the aortic position. METHODS: A total of 280 patients were operated on from June 1993 to July 1999 as part of a multicenter investigation. Factors influencing hospital mortality and long-term survival were assessed by logistic regression and Cox proportional hazards analysis. Patients were evaluated postoperatively at discharge, at 3 to 6 months, and yearly by clinical examination and color flow Doppler echocardiography. RESULTS: Hospital mortality in this group was relatively high (9.6%). Logistic regression analysis showed that cross-clamp time, age, myocardial infarction, diabetes, left ventricular hypertrophy, coronary artery disease, New York Heart Association class III or IV and female gender were the independent predictive factors. According to the Kaplan-Meier method, the 4-year survival for hospital survivors was 94%. In the multivariate Cox proportional hazard analysis, only coronary artery disease proved to be prognostic. During follow-up, 11 patients developed paravalvular leakage due to prosthetic dehiscence at the side of the noncoronary cusp. Performance of the prosthesis as assessed by echocardiography was excellent. Mean gradient decreased significantly between discharge and follow-up at 3 to 6 months. At 1-year follow-up trivial regurgitation was found in 6 patients (3%) and mild regurgitation in 4 (2%). Regurgitation did not increase with time. The effective orifice area increased significantly from discharge to follow-up at 3 to 6 months. CONCLUSIONS: Hospital mortality after implantation of a stentless bioprosthesis was higher compared to conventional prosthesis. A high incidence of prosthesis dehiscence at the proximal suture line was found, which was probably due to technique. Hemodynamic performance up to 3 years showed low transvalvular gradients. There is echocardiographic evidence for reduction of left ventricular hypertrophy and improvement of left ventricular function.

Actuarial Analysis↗
PubMed2004

Early experience with percutaneous transcatheter implantation of heart valve prosthesis for the treatment of end-stage inoperable patients with calcific aortic stenosis.

OBJECTIVES: This study was done to assess the results of percutaneous heart valve (PHV) implantation in non-surgical patients with end-stage calcific aortic stenosis. BACKGROUND: Replacement of PHV has been shown to be feasible in animals and humans. We developed a PHV composed of three pericardial leaflets inserted within a balloon-expandable stainless steel stent. We report the acute and early follow-up results of the initial six PHV implantations. METHODS: An anterograde approach was used in all cases. The PHV, crimped over a 22-mm diameter balloon, was advanced through a 24-F sheath from the femoral vein to the aortic valve and delivered by balloon inflation. Clinical, hemodynamic, and echocardiographic outcomes were assessed serially. RESULTS: All patients were in New York Heart Association functional class IV. The PHV was successfully delivered in five patients. Early migration with subsequent death occurred in one patient who presented with a torn native valve. Acute hemodynamic and angiographic results showed no residual gradient, mild (three patients) or severe (two patients) aortic regurgitation, and patent coronary arteries. On echocardiography, the aortic valve area was increased from 0.5 +/- 0.1 cm(2) to 1.70 +/- 0.03 cm(2) and the aortic regurgitation was paravalvular. Marked and sustained hemodynamic and clinical improvement was observed after successful PHV implants. The first three patients died of a non-cardiac cause at 18, 4, and 2 weeks, respectively, and the other patients are alive at 8 weeks with no signs of heart failure. CONCLUSIONS: Implantation of the PHV can be achieved in patients with end-stage calcific aortic stenosis and might become an important therapeutic option for patients not amenable to surgical valve replacement.

Aged↗
PubMed1994

[Transesophageal echocardiography assessment of regurgitant jets of eccentric geometry in mitral valve prosthesis: superiority of multiplanar sections over standard sections].

OBJECTIVE: The purpose of this study was to determine whether multiplanar (MP) transesophageal echocardiographic views were superior to standard views (ST) at 0 degree and 90 degrees in the evaluation of mitral prosthesis regurgitation (MR), particularly in presence of wall regurgitant jets. DESIGN: Comparison between MP and ST views in the evaluation of mitral prosthesis regurgitation. SETTING: Laboratory of Echocardiography of the General Hospital Gregorio Marañon. MATERIAL AND METHODS: Study of all mitral prostheses in which pathological mitral regurgitation had been detected by multiplanar TEE, between January 1993 and March 1994. Regurgitation prosthesis were classified in two groups according to the presence of wall regurgitation jets and maximum turbulent color flow areas (MAX) were measured on standard (0 degree and 90 degrees) and MP (0 degree to 180 degrees) views. The sample was divided in two groups, A (n = 33): with wall jets and B (n = 10): without wall jets. Students' t test was used to compare both areas using a 95% confidence interval (95% c.i.). RESULTS: MAX detected on ST views were of 5.80 +/- 4.60 cm2 and on MP were of 7.42 +/- 5.13 cm2 being the difference statistically significant: 1.61 cm2, 95% c.i. from 0.94 to 2.28 cm2, p = 0.000025. MAX for group A was of 5.64 +/- 4.30 cm2 in ST views and of 7.51 +/- 5.12 cm2 in MP views, being the difference 1.86 cm2, 95% c.i. from 1.04 to 2.68; p = 0.00009. Differences for group B were also statistically significant: 0.68 cm2, p = 0.0176. Mitral regurgitation (MR) was classified as mild, moderate and severe according to the color flow area. MP views detected a severer degree of MR than ST views in 8 patients, all of them with wall regurgitation jets. Three of these cases had been considered normal on ST views. CONCLUSIONS: Multiplanar transesophageal views are significantly superior to standard views in the assessment of regurgitant prosthetic mitral valves, particularly in presence of wall regurgitant jets. Our data strongly suggest that multiplanar TEE is the procedure of choice in the assessment of wall regurgitant mitral prostheses.

Adult↗
PubMed1999

[Percutaneous treatment of a superficial femoral artery aneurysm using an intravascular stent-prosthesis].

One case of superficial femoral aneurysm treated percutaneously by endovascular stent graft (Passager Boston) is reported. The initial radiographic evaluation included arteriography and color doppler sonography which enable analysis of the flow path, the extent of the wall thrombus, the choice of stended graft size. The procedure of implantation was technically trouble free. The post-procedure 3D CT and arteriography demonstrated occlusion of the aneurysm and resaturation of normal flow path. The six and twelve month check confirmed the stability of the results locally and the integrity of run off vessels. In weakened and specially elderly patient percutaneous treatment of superficial femoral artery aneurysm can be carried out easily. The contribution of 3D CT is essential in follow up to ensure an optimal result and to detect any complication.

Aged↗
PubMed2006

Mitral valve surgery simultaneous to coronary revascularization in patients with end-stage ischemic cardiomyopathy.

Mitral valve regurgitation (MVR), occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction, predicts a poor outcome in terms of survival and morbidity. Between 1995 and 2003, 180 consecutive patients with impaired LV function and chronic ischemic MVR underwent cardiac surgery. Fifty-four patients (group I), MVR (grade III-IV) underwent simultaneous MV surgery and coronary artery bypass grafting (CABG); 40 patients (group II), MVR (grade II-III), and 86 patients (group III), MVR (grade I-II), underwent CABG alone. In group I, MV repair was performed in 36 patients (group IA) and MV replacement in 18 (group IB). The incidence of hospital death was similar between groups. The actuarial event-free survival was significantly lower in group than in groups II and III (P = 0.0045) and I (P = 0.038). The overall actuarial survival was significantly higher in group IA than in group IB (P = 0.027). Postoperatively, the LV ejection fraction (P < 0.001), LV end-diastolic diameter (P < 0.001), LV end-systolic diameter (P < 0.01), and cardiac index (P < 0.001) improved significantly in group I. The regurgitation fraction decreased significantly in Groups I and III after surgery (P < 0.001 and P = 0.003, respectively). Both MV repair and replacement that preserves subvalvular apparatus in patients with end-stage ischemic myocardiopathy offer an acceptable outcome. Mitral valve repair simultaneous to CABG improves significantly the LV function and its geometry. In patients with mild to moderate mitral regurgitation, CABG alone may be performed with good overall survival, but with lower event-free survival than those undergoing concomitant mitral valve repair.

Aged↗
PubMed1996

Meniscal repair by fibrocartilage in the dog: characterization of the repair tissue and the role of vascularity.

Lesions in the avascular part of 20 canine menisci were repaired by implantation of a porous polyurethane. Seven menisci were not repaired and served as controls. The repair tissue was characterized by biochemical and immunological analysis. The role of vascularity in healing was studied by perfusion of menisci with Indian ink. Histologically, repair tissue inside the implants initially consisted of fibrous tissue containing type I collagen. After 2 months, fibrocartilaginous tissue developed inside the implants, whereas control defects only showed repair with fibrous tissue. Both type I and type II collagen, the two major collagen types of normal meniscal fibrocartilage, could be detected in this newly formed fibrocartilage. The implant guided vascular tissue from the periphery towards the lesion resulting in healing of the tear. After fibrocartilage had formed, vascularity decreased and was completely absent in mature fibrocartilage. Control defects remained filled with vascular connective tissue. Two-thirds of the longitudinal lesions were found to be healed partially or completely. It is concluded that implantation of a porous polymer does enhance vascularity sufficiently to result in healing of meniscal lesions extending into the avascular part. Healing takes place by repair tissue strongly resembling normal meniscal fibrocartilage.

Animals↗
PubMed1995

Is there a hemispheric side preference of cardiac valvular emboli?

Microaggregates arising from prosthetic cardiac valves offer the opportunity to examine the distribution of valvular emboli in the human cerebral circulation. Forty-four patients with different kinds of prosthetic valves underwent bilateral transcranial Doppler monitoring for 1 h to detect high intensity Doppler signals representing microemboli. Comparing the total number of embolic signals in both middle cerebral arteries (N = 1066), a side preference was not statistically evident. However, clear side preferences were obvious in some individuals. The lack of statistical evidence for hemispherical preferences of cardiac microembolism in general does not exclude selective streaming in individuals, explaining the clinical observation of lodging preferences of recurrent cardiac embolism. A cardiac source of microembolism may mimic disease activity of extracranial carotid artery stenosis and bias the localization of embolic source.

Adult↗
PubMed1996

Estimation of pulmonary artery pressure by spectral analysis of the second heart sound.

The objective of the present work was to test and validate a noninvasive method based on spectral analysis of the second heart sound (S2) to estimate the pulmonary artery (PA) systolic pressure in 89 patients with a bioprosthetic heart valve. The technique was compared with continuous-wave Doppler estimation of PA systolic pressure in these patients. The heart sounds recorded at the pulmonary area on the chest wall were digitized by computer. The spectra of S2 and those of the aortic (A2) and the pulmonary (P2) components of S2 were computed with a fast-Fourier transform. Seven features were extracted from these spectra. The statistical analysis performed with the Pearson linear correlation coefficient showed that the best estimation of PA systolic pressure obtained by spectral phonocardiography (r = 0.84, SEE +/- 5.6 mm Hg, p <0.0001) was provided by the following equation: PA systolic pressure = 47 + 0.68 Fp - 4.4 Qp - 17 Fp/Fa - 0.15 Fs, where Fs and Fp are dominant frequencies associated with the maximal amplitude of the power spectra of S2 and P2, respectively, Qp is the quality of resonance of P2, and Fp/Fa is the ratio of the dominant frequencies of P2 and A2, respectively.

Adult↗
PubMed1998

Long-term follow-up of rheumatic patients undergoing left-sided valve replacement with tricuspid annuloplasty--validity of preoperative echocardiographic criteria in the decision to perform tricuspid annuloplasty.

Between September 1989 and December 1991, modified De Vega tricuspid annuloplasty was performed in 43 patients who survived surgery for mitral or mitral plus aortic valve replacement. The preoperative indications for tricuspid annuloplasty were moderate to severe tricuspid regurgitation (TR) in 33 patients and mild or no TR but with a dilated tricuspid annulus (> or =30 mm) as measured by 2-dimensional echocardiography at end-diastole in 10 patients. The mean age was 31 +/- 13 years. The mean duration of follow-up was 57 +/- 18 months. Overall long-term mortality was 12%. On Doppler color flow mapping, postoperative severe TR was present in 1 patient and moderate TR in 4 patients at latest follow-up. The tricuspid annulus diameter decreased from 37 +/- 5 mm preoperatively to 24 +/- 6 mm at latest follow-up. During the study period, an additional 77 patients underwent mitral valve replacement or double valve replacement, but without tricuspid annuloplasty. Within this group, 38 patients had a preoperative tricuspid annulus diameter of > or =30 mm, and 5 of these patients (13%) developed moderate or severe TR in the postoperative period, which may have been prevented had clinicians adhered to the preoperative indications for tricuspid annuloplasty. Thus, preoperative echocardiographically documented moderate or severe TR or a tricuspid annulus diameter of > or =30 mm are valid indications for performing tricuspid annuloplasty; modified De Vega tricuspid annuloplasty is a durable procedure in rheumatic patients; it appears that reducing the diastolic tricuspid annulus diameter to 24 mm is adequate to prevent residual TR in the long term.

Adult↗
PubMed1995

Echocardiographic assessment of aortic valve replacement with stentless porcine xenografts.

Stentless porcine xenografts (SPXs) implanted in the aortic position have potential hemodynamic advantages over traditional valve prostheses because of the lack of a rigid stent. Twenty-four patients (mean age 59 years) who underwent aortic valve replacement with SPXs were studied by echocardiography early after and 26 +/- 10 months (range 8 to 40) after operation. Peak and mean gradients, as well as aortic valve area, did not change significantly from baseline (16.3 +/- 8 and 9.8 +/- 5.6 mm Hg, and 1.78 +/- 0.63 cm2, respectively) to follow-up study (12.5 +/- 5 and 7.7 +/- 3 mm Hg, and 1.8 +/- 0.65 cm2, respectively). At baseline, color flow Doppler imaging showed aortic valve regurgitation where the leaflets coapted centrally in 17 of 24 patients (trivial, n = 14; mild, n = 3). Besides the central leak, paravalvular regurgitation was seen in 4 patients (trivial, n = 3; mild, n = 1). At follow-up, 18 of 24 patients had aortic valve regurgitation (trivial, n = 11; mild, n = 6; and moderate, n = 1). New valvular regurgitation (graded as trivial, n = 2; mild, n = 2; and moderate, n = 1) was detected in 5 patients, and new paravalvular regurgitation (graded as mild) developed in 1 patient. Two patients underwent repeat operation for valve-related complications: (1) rupture of a valve cusp with acute pulmonary edema, and (2) fibrotic stenosis of the left coronary ostium with unstable angina. In conclusion, this study demonstrates good hemodynamic performance of the SPX in the aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

Microdamage accumulation in the cement layer of hip replacements under flexural loading.

Mechanical fatigue of bone cement leading to damage accumulation is implicated in the loosening of cemented hip components. Even though cracks have been identified in autopsy-retrieved mantles, damage accumulation by continuous growth and increase in number of microcracks has not yet been demonstrated experimentally. To determine just how damage accumulation occurs in the cement layer of a hip replacement, a physical model of the joint was used in an experimental study. The model regenerates the stress pattern found in the cement layers whilst at the same time allowing visualisation of microcrack initiation and growth. In this way the gradual process of damage accumulation can be determined. Six specimens were tested to 5 million cycles and a total of 1373 cracks were observed. It was found that, under the flexural loading allowed by the model, the majority of cracks come from pores in the bulk cement and not from the interfaces. Furthermore, the lateral and medial sides have statistically different damage accumulation behaviours, and pre-load cracks significantly accelerate the damage accumulation process. The experimental results confirm that damage accumulation commences early on in the loading history and that it is continuously increasing with load in the form of crack initiation and crack propagation. The results highlight the importance of replicating the loading and restraint conditions of clinical cement mantles when endeavouring to accurately model the damage accumulation process.

Aluminum↗
PubMed1999

Composite veneered acrylic resin provisional restorations for complete veneer crowns.

Restorations that are remade to improve esthetics, teeth with pronounced gingival-to-incisal color contrast, or high-value translucent teeth can limit the capability of shaded acrylic resin provisional restorations to satisfy the esthetic demands of certain patients. This article describes a procedure to incorporate a composite veneer in an acrylic resin provisional restoration. Improved optical properties of microfilled composite are combined with the excellent marginal seal and contour of acrylic resin. Precise control of color, translucency, and surface texture provide excellent interim esthetics and a better guide for the definitive prosthesis.

Acrylic Resins↗