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PubMed1993

Improvement in the diagnosis of bioprosthetic valve dysfunction by transesophageal echocardiography.

Transthoracic two-dimensional echocardiography has been considered the method of choice for the non-invasive assessment of bioprosthetic valves. Recently, transesophageal echocardiography has provided a better imaging window for detecting valve abnormalities not identified otherwise, but pathologic confirmation is essential to establish the role of new diagnostic techniques in clinical practice. Therefore, the purpose of this study was to evaluate the usefulness of transesophageal echocardiography in determining the etiology of bioprosthetic valve dysfunction. Transthoracic and transesophageal two-dimensional and color-flow Doppler echocardiography were performed on 44 consecutive patients with suspected bioprosthetic dysfunction who underwent surgical intervention. At surgery a total of 63 abnormalities in 44 bioprostheses were identified: 31 (49.2%) flail cusps, 14 (22.2%) vegetations, four (6.3%) abscesses, four (6.3%) dehiscences, and 10 (15.9%) stenoses. Transesophageal echocardiography was superior to its transthoracic counterpart for the detection of flail cusps (96.7% vs. 54.8%, p < 0.01), vegetations (85.7% vs. 42.8%, p < 0.01), abscesses (100% vs. 25.0%, p < 0.05), and dehiscences (100% vs. 25.0%, p < 0.05). All patients with flail cusps had severe regurgitation as evaluated by color-flow Doppler. In bioprosthetic mitral stenosis, both methods provided accurate estimates of valve area, while in bioprosthetic aortic stenosis, transthoracic Doppler velocity measurements allowed calculation of valve area in four of six patients. In two patients with high flow velocities, the valve area was not estimated because of an inability to measure the left ventricular outflow tract dimension. Conversely, the transesophageal approach provided measurement of the outflow tract in all six patients, but Doppler velocities were not obtained in any of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1990

A survey of dentists practicing implant dentistry in Israel.

Due to the increasing interest in the field of implant dentistry, a first survey of dentists in Israel who used implants was conducted. Out of a total of 312 dentists questioned, 97 reported using dental implants in their practice. In spite of the team approach advocated in the literature, 40% of the dentists in the survey conducted both the surgical and the prosthetic phases of treatment. Over 60% of the respondents had less than 3 years' experience in the field, which is in keeping with the worldwide trend. A smaller number than expected regarded red gingival color and bone resorption based on radiographic findings as grounds for implant failure. In the view of at least 10 respondents, pain, discomfort, exudate, and fistulization did not indicate unsuccessful implants. A disparity was revealed between the dentists' practice methods and their hypothetical choice of self-treatment. Although the Core-Vent method was the most widely employed, only 50% of those using this system preferred it for themselves. Even fewer (25%) of those using blade implants considered it their self-treatment of choice. In contrast, although only 10% of the dentists had used the Branemark method, 30% preferred it for their own treatment.

Attitude of Health Personnel↗
PubMed1999

[The pericardium: a heterogeneous tissue. Anatomic and morphometric considerations].

BACKGROUND AND AIMS OF THE STUDY: Short-term glutaraldehyde fixed autologous pericardium is widely used in cardiac valve repair or in autologous pericardial bioprosthesis construction. The thinner the tissue, the better the fixation. The aim of this study was to determine thickness and useful surface area of pericardium in relation to harvesting site using a digital thickness counter (0.01 mm precision). Parietal pericardium fragments were obtained from the pericardial sac of six fresh cadavers (group I). In the other groups, pericardial strips (80 x 30 mm) were obtained from patients undergoing surgery: group II patients (n = 5 females) and group III (n = 10 males) were non-cardiomegalic (cardiothoracic ratio (CTR) < 0.5)), while group IV patients (n = 5) were all cardiomegalic (CTR > 0.5). Results were reported on a coloric scale according to measurement position. In group I, mean surface area was 93 +/- 18 cm2, and thickness gradually increased from 0.1 to 0.6 mm, maximally on the diaphragm, along the left heart side. In other groups, a gradual increase in thickness was identified towards the diaphragmatic zone. Significant differences in tissue thickness appear as a result of cardiomegaly, but are not related to the sex of the patients. Pericardium taken from the right anterior aspect of the pericardial sac in patients without cardiomegaly is the most appropriate tissue for valve reconstructive surgery, due to its thin nature and hence better fixation properties.

Analysis of Variance↗
PubMed1998

Prevalence of microembolic signals in patients with different types of mono-leaflet and bi-leaflet prosthetic heart valves.

Microembolic signals (MES) have been described in patients with different types of prosthetic valves. The aim of our study was to compare prevalence of MES in patients with mono-leaflet and bi-leaflet valves, and to correlate them with different clinical and echocardiographic parameters. We evaluated 42 patients, 15 with mono-leaflet and 27 with bi-leaflet valves, with 30-minute bilateral simultaneous transcranial Doppler monitoring for the identification of MES. All patients performed blood testing for international normalized ratio (INR), color-coded duplex of supra-aortic vessels, and echocardiography. Eighteen patients (43%) showed MES; 61% of MES were detected bilaterally, 17% only on the left and 22% only on the right middle cerebral artery (MCA), with no interhemispheric difference. MES did not correlate with patient's age, echocardiographic parameters, INR, presence of atrial fibrillation, or site of valve replacement. One (7%) of the 15 patients with mono-leaflet valves had MES, as opposed to 17 (63%) of the 27 with bileaflet valves (p=0.0003). Patients with bileaflet valves and MES had valves of older implantation and, only for aortic valves, larger valve size.

Adult↗
PubMed2005

Effect of L-carnitine on cardiomyocyte apoptosis and cardiac function in patients undergoing heart valve replacement operation.

The effects of L-carnitine, as an ingredient of cardioplegia solution, on cardiac function and cardiomyocyte apoptosis in patients undergoing heart valve replacement operation were investigated. Twenty-three cases undergoing heart valve replacement with cardiopulmonary bypass (CPB) were randomly allocated into two groups: L-carnitine group (n = 12, 12 g/L L-carnitine was put in the ST. Thomas cardioplegia) and control group (n = 11, identical to the L-carnitine group except that normal saline was administered instead of L-carnitine). Serum cardial troponin I (cTnI) levels, the left ventricular ejection fraction (LVEF), and cardiac index (CI) were measured perioperatively. A bit of myocardial tissue obtained from right atria was taken before CPB and by the end of intracardiac procedure to undergo electron microscopy examination and estimate apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). From the end of CPB to 3 days after operation, the serum levels of cTnI in the L-carnitine group was significantly lower than that in the control group (P < 0.05). Heart color ultrasonogram showed that the CI index and LVEF at 7th day postoperatively in the L-carnitine group were significantly higher than in the control group (P < 0.05). Compared to the control group, L-carnitine significantly alleviated the morphologic changes of cardiac muscle cells (electron microscopy examination) and decreased the amounts of apoptotic cardiac muscle cells (TUNEL). Furthermore, the dosage of vasoactive drugs used after operation was significantly less in the L-carnitine group (P < 0.01). It was concluded that L-carnitine cardioplegia solution could improve cardiac function in patients undergoing heart valve replacement operation and alleviate CPB-mediated apoptosis of cardiac muscle cells.

Adult↗
PubMedDate not supplied

Percutaneous treatment of iliac aneurysms and pseudoaneurysms with Cragg Endopro System 1 stent-grafts.

PURPOSE: To evaluate the feasibility and short-term follow-up results of treating iliac aneurysms by the Cragg Endopro System 1 stent-graft. METHODS: Nine lesions (two pseudoaneurysms and seven atherosclerotic aneurysms) were treated in eight patients by percutaneous implantation of a total of 10 stent-grafts. The procedure was followed by anticoagulation with heparin for 6 days, then antiplatelet therapy. Follow-up was by color Doppler ultrasound scan at 2 days and 3 months after the procedure for all patients, and by venous digital subtraction angiography and/or angio-CT up to 12 months later for four patients. RESULTS: Initial clinical success rate was 100% and there were two minor complications. In one case the delivery system was faulty resulting in failure to deploy the stent-graft. An additional device had to be used. At 3-12 months all prostheses were patent but one patient (12.5%) had a minimal pergraft leak. CONCLUSION: Percutaneous stent-grafting with this device is a safe and efficacious treatment of iliac artery aneurysms.

Aged↗
PubMed1989

Doppler color flow evaluation of prosthetic mitral valves: experimental epicardial studies.

More than 300 epicardial Doppler color flow mapping studies on 23 different types of clinical and preclinical valves were performed after implantation in the mitral position in sheep. The transducers were placed directly on the heart to obtain the greatest possible resolution. Studies were performed in each animal under different hemodynamic conditions by varying heart rate and cardiac output. Eighty-six valves were studied late (20 to 52 weeks), whereas the remainder were studied early (0 to 10 days) after operation. The valves included 3 types of ball and cage valves, 3 types of disc and cage valves, 7 types of tilting disc valves, 1 type of bileaflet hemidisc mechanical valve, 13 types of porcine aortic valves and 5 types of bovine pericardial valves. The results of these studies were compared with those obtained in 40 studies of 20 native mitral valves. Doppler color velocity/flow profiles were imaged in real time with simultaneous electrocardiographic gating; the aortic flow was also displayed for the timing of velocity/flow events. Native normal mitral valves had no in-orifice flow disturbances and laminar low velocity/flow directed toward the left ventricular apex. Ball and cage and disc and cage valves had high velocity peripheral jets and vortices of velocity/flow reversals distal to the occluders. Tilting disc valves had differing velocity/flow patterns determined by their orientation in the mitral anulus. Bileaflet hemidisc valves had three jets, which decayed 1.5 cm downstream. Porcine aortic and bovine pericardial bioprosthetic valves had high velocity, turbulent, nonaxisymmetric jets (more severe for the latter).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1999

Dynamic three-dimensional reconstruction of the heart by transesophageal echocardiography.

OBJECTIVE: To evaluate echocardiography accuracy in performing and obtaining images for dynamical three-dimensional (3D) reconstruction. METHODS: Three-dimensional (3D) image reconstruction was obtained in 20 consecutive patients who underwent transesophageal echocardiography. A multiplanar 5 MHz transducer was used for 3D reconstruction. RESULTS: Twenty patients were studied consecutively. The following cardiac diseases were present: valvar prostheses--6 (2 mitral, 2 aortic and 2 mitral and aortic); mitral valve prolapse--3; mitral and aortic disease--2; aortic valve disease--5; congenital heart disease--3 (2 atrial septal defect--ASD- and 1 transposition of the great arteries-TGA); arteriovenous fistula--1. In 7 patients, color Doppler was also obtained and used for 3D flow reconstruction. Twenty five cardiac structures were acquired and 60 reconstructions generated (28 of mitral valves, 14 of aortic valves, 4 of mitral prostheses, 7 of aortic prostheses and 7 of the ASD). Fifty five of 60 (91.6%) reconstructions were considered of good quality by 2 independent observers. The 11 reconstructed mitral valves/prostheses and the 2 reconstructed ASDs provided more anatomical information than two dimensional echocardiography (2DE) alone. CONCLUSION: 3D echocardiography using a transesophageal transducer is a feasible technique, which improves detection of anatomical details of cardiac structures, particularly of the mitral valve and atrial septum.

Adult↗
PubMed1995

Direction or reversal of preshunt portal blood flow as determinants of outcome up to 1 year after small-diameter prosthetic H-graft portacaval shunt.

Partial portal decompression (PPD) is gaining popularity in the treatment of portal hypertension. We have achieved PPD in over 80 patients by utilizing an 8-mm prosthetic H-graft portacaval shunt (HGPCS). We have been pleased with the infrequency of encephalopathy and liver failure after shunting. While maintenance of portal blood flow would presumably play a role in outcome after shunting, changes in portal hemodynamic occurring within the first year after shunting are generally unknown. In 31 patients (Child's class 6% A, 61% B, 32% C) of an average age of 55 +/- 13.3 (SD) years undergoing HGPCS, clinical outcome was prospectively evaluated relative to the direction of portal blood flow determined before and after shunting and at 1 year after shunting using color-flow Doppler ultrasound. Preshunt hepatopetal flow reversed in 2/29 (7%) patients with shunting and in an additional 5/27 (18%) patients by 1 year after shunting. Death (due to alcoholism in 1, old age in 1) and encephalopathy (Child's class A = 1, B = 2, C = 1) were uncommon by 1 year after shunting. Eighty-one percent had excellent outcome (alive without encephalopathy or rebleeding) at 1 year. Though preshunt hepatopetal flow is generally maintained postshunt and after one year, maintenance of hepatopetal flow does not ensure an excellent outcome and reversal of hepatopetal flow does not pre-dispose to a suboptimal outcome. Outcome up to 1 year after HGPCS is not determined by direction or reversal of portal blood flow.

Aged↗
PubMed1988

Left ventricular outflow obstruction after mitral valve repair (Carpentier's technique). Proposed mechanisms of disease.

Left ventricular outflow tract obstruction (LVOTO) after mitral valve repair by Carpentier's technique has been recently reported in the literature. To assess the mechanisms of this phenomenon, we investigated 307 mitral valve repairs performed between July 1985 and December 1986. Incidence of LVOTO related to the mechanism of the mitral insufficiency and to the etiology demonstrates a direct relation to preoperative mitral valve prolapse (posterior leaflet +/- anterior leaflet) of degenerative origin. No LVOTO occurred after rheumatic mitral insufficiency repair regardless of size of the left heart cavities or of the prosthetic ring. Intraoperative and surficial two-dimensional echocardiography, color Doppler methods, and cardiac catheterization were used to investigate the mechanisms leading to LVOTO. Nonspecific modifications induced by reduction in size of the mitral annulus by the prosthetic ring (anterior displacement of the posterior ventricular wall and of the posterior mitral leaflet and narrowing of the mitroaortic angle) are not sufficient to explain the LVOTO. The association of mitral leaflets (composed of excess tissue and opposed to flow by a perpendicular position attributable to a narrow mitroaortic angle) and geometric left ventricular modifications (responsible for the superposition of mitral inflow to ventricular outflow) also qualifies as a mechanism for the induction of LVOTO after mitral surgical repair.

Cardiac Catheterization↗
PubMedDate not supplied

The aesthetic composite anterior single crown restoration.

Achieving natural aesthetics by harmoniously matching the shape and color of a single anterior crown is perhaps one of the greatest challenges in restorative dentistry. The clinician must often rely on the artistic skills of a laboratory technician who has no direct access to the patient. The shade selection process is, therefore, impaired, and the final result may be a restoration which does not emulate the aesthetics of the adjacent natural dentition. The learning objective of this article is to present an innovative technique which utilizes the qualities of high strength laboratory processing in association with the application of light curing and freehand bonding of composite resins. This combination allows the clinician to predictably achieve aesthetic results with single anterior crowns. The direct, indirect, and indirect/direct restorations are discussed, and the laboratory and clinical procedures are reviewed.

Composite Resins↗
PubMed1994

Size and shape of biomaterial wear debris.

A literature review of wear debris is presented. Included are debris retrieved at revision of total joint replacement and at autopsy, as well as debris produced in vitro in wear testers and joint simulators or otherwise fabricated for biological experiments. Observations of wear debris in vivo and in vitro are classified in tabular form according to material type, origin, size, shape and color. Polymer particles, most commonly ultra-high molecular weight polyethylene (UHMWPE), exhibit the largest size range and appear as granules, splinters or flakes, while ceramic particles possess the smallest size range and have a granular structure. Metal particles seen in vivo and in vitro, whether from cobalt-chromium alloys or, less frequently, other alloys, form granular or needle-like shapes and generally are smaller than polymer particles but larger than ceramic particles. Particles generated in joint simulators resemble the size and shape of in vivo wear particles from total joint replacement (TJR) retrieved at revision or autopsy. However, particles prepared in vitro, whether in simulators or by other means, do not consistently resemble wear debris particles from TJR.

Biocompatible Materials↗
PubMed2005

Percutaneous transcatheter coil embolization of a ventricular septal defect in a dog.

A 4-month-old male French Bulldog weighing 5.0 kg (11 lb) was referred for a heart murmur. A grade 3/6 systolic murmur was detected at the left heart base and a grade 4/6 systolic murmur was detected at the right heart base. By use of color-flow Doppler ultrasonography and cardiac catheterization, a diagnosis of supracristal ventricular septal defect (VSD) with accompanying aortic regurgitation was made. Percutaneous transcatheter coil embolization was used to close the VSD. Because residual shunt was detected via echocardiography after coil implantation, the residual shunt was followed periodically via echocardiography to detect spontaneous closure of the VSD. Volume overload in the left ventricle was detected in the dog 131 days after admission. Additional coils were placed 137 days after admission. Hemolysis resulting in hemoglobinuria was detected, but this complication was mild. In the dog of this report, results of coil occlusion for correction of VSD were promising. Thus, coil occlusion should be considered as an alternative treatment for VSD in dogs.

Animals↗
PubMedDate not supplied

In vitro quantification of regurgitant jet flow by color Doppler ultrasound and conservation of momentum.

Prosthetic valve regurgitant jets can be imaged with color Doppler ultrasound (CDU), but clinical quantitation remains elusive. An equation based on an integrated conservation of momentum analysis was implemented for CDU quantitation of regurgitation. This was compared with a simple, non-CDU momentum balance analysis recently reported that requires only a pulsed Doppler ultrasound (PDU) reading within the jet and a continuous wave Doppler (CWD) reading of the orifice velocity. For in vitro steady flows, the simple, non-CDU method was accurate only with PDU readings taken 5 cm from the orifice; flows were underestimated when readings 1 and 3 cm from the orifice were used. The CDU method was accurate, even when flows calculated from readings between 0.5 and 6.0 cm from the orifice were averaged together.

Blood Flow Velocity↗
PubMed1998

Procera: a new way to achieve an all-ceramic crown.

The Procera System embraces the concept of computer-assisted design and computer-assisted machining to fabricate an all-ceramic crown composed of a densely sintered, high-purity aluminum oxide coping combined with a compatible veneering porcelain. Strength, precision of fit, color stability, cementation, and wear characteristics are among the many factors that concern clinicians when fabricating all-ceramic restorations with this new crown system. This article presents, in summary form, the data from the many studies on Procera AllCeram crowns that have been conducted at clinical and laboratory centers around the world. The evidence reported in these studies clearly demonstrates that the Procera AllCeram crown represents a combination of computer technology and creativity for which a positive prognosis can be made. Today its application is restricted to single crowns; however, with continued development, multiple unit all-ceramic anterior and posterior fixed partial dentures are clearly in the future.

Cementation↗
PubMed2003

Multicenter trial of the Jostent balloon-expandable stent-graft in renal and iliac artery lesions.

PURPOSE: To report the results of a multicenter feasibility study of the Jostent balloon-expandable stent-graft in the treatment of renal and iliac artery lesions. METHODS: Twenty-three patients (17 men; mean age 62 years, range 38-80) with lesions in the renal (n=12) or iliac arteries (n=12) were enrolled in 6 centers over a 1-year period. Preprocedural computed tomography (CT) and angiography were performed in all patients. The Jostent device was implanted in the 24 arteries to treat 11 in-stent stenoses, 2 arterial ruptures, 2 aneurysms, 2 dissections, 2 ulcerated stenoses, and 5 chronic occlusions. Follow-up included color duplex ultrasound examination on the day after the procedure and at 6 months; patients with renal artery stent-grafts were also evaluated with CT angiography. RESULTS: Twenty-seven stent-grafts were deployed successfully in the 24 (100%) arteries. Seven (30%) patients required adjunctive procedures to address 1 acute in-stent thrombosis, 2 dissections, and 4 in-stent residual stenoses. At 6-month follow-up, 2 (8.3%) restenoses occurred in the renal arteries; these were treated successfully using balloon angioplasty. CONCLUSIONS: These data suggest that a balloon-expandable stent-graft may be safe and useful in patients with selected peripheral indications.

Adult↗
PubMed1991

[Cardiological diagnosis in arterial embolism].

Potential cardiac sources of arterial embolism are in particular thrombi within the left atrium or ventricle, or attached to a prosthetic valve, intracardiac tumors, and vegetations due to endocarditis. Patent foramen ovale and atrial septal defect may lead to paradoxical embolism, and spontaneous echo contrast within the heart has to be considered as a parameter of increased thromboembolic risk. In rare cases, atrial septal aneurysm, mitral valve prolapse or annulus calcification and calcified aortic stenosis has to be taken into consideration. Current method of choice for diagnosis of these abnormalities is echocardiography. When the transthoracic approach fails, transesophageal echocardiography (TEE) leads to a definite diagnosis in most cases. Precordial echocardiography allows the detection of left ventricular thrombi with a sensitivity ranging between 72 and 95%, and monoplane TEE does usually not increase these numbers. In contrast, thrombi within the left atrium and particularly in the left atrial appendage can be detected with a significantly higher detection rate when TEE is used. The same is true for spontaneous echo contrast in the left atrium, a phenomenon which is almost exclusively diagnosed by TEE, as well as for endocarditis associated vegetations that can be identified by TEE with a sensitivity higher than 90%. Patient foramen ovale is usually diagnosed by precordial contrast echocardiography combined with a Valsalva maneuver; color Doppler or contrast TEE allows to increase the detection rate. In the diagnosis of prosthetic valve attached thrombi and vegetations, TEE is clearly superior compared to the precordial examination, at least concerning prosthetic devices in mitral position. If echocardiography fails to identify a potential cardiac source of embolism, other techniques don't add significant information in most cases. Detection of a potential source of embolism, however, does not necessarily prove that the particular finding represents the true etiology of an embolic event; results of all clinical and technical examinations have to be evaluated in a critical synopsis. In addition, proper therapeutic consequences in quite a number of abnormalities considered as potential cardiac sources of embolism are not yet defined.

Echocardiography↗
PubMed2001

Renal artery stenting in patients with a solitary functioning kidney.

PURPOSE: To retrospectively evaluate the results of renal artery stenting in patients with renovascular disease and a solitary functioning kidney. METHODS: Palmaz stents were placed in 16 patients with a solitary functioning kidney, renal artery stenosis, hypertension and renal failure. Stenoses were evaluated with color Doppler ultrasound, MR angiography and digital subtraction angiography (DSA). Indications for stenting were: recoil after percutaneous transluminal renal angioplasty (PTRA) (63%), arterial dissection after PTRA (13%) and primary stenting (25%). Immediate results were evaluated by DSA. On follow-up (6-36 months), patients underwent periodical evaluation of clinical conditions (blood pressure and serum creatinine level) and stent patency, by means of color Doppler ultrasound. RESULTS: Stent placement was successful in all patients (100%). Cumulative primary patency rate was: 100% at 1 day, 93.75% at 6 months, 81.25% at 12 months and 75% at 24 months. A significant reduction in diastolic blood pressure occurred (mean +/- SD 104 +/- 6 vs 92 +/- 3; p < 0.05); renal function improved or stabilized in over 80% of patients. However, there was no significant difference in the creatinine values before and after treatment (mean +/- SD 200 +/- 142 micromol/l vs 197 +/- 182 micromol/l; p > 0.05). CONCLUSION: Renal artery stenting, both after PTRA and as primary stenting, represents a safe procedure, able to preserve renal function in patients with a solitary functioning kidney.

Adult↗