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At least 991 records · Page 55Linked to original sources
PubMedDate not supplied

Device closure of an atrial septal defect following successful balloon valvuloplasty in a neonate with critical pulmonary valve stenosis and persistent cyanosis.

Persistent cyanosis after successful balloon valvuloplasty for neonatal critical pulmonary valve stenosis is often related to poor right ventricular compliance and right-to-left shunting at the atrial level. A successful catheter closure of an atrial septal defect was performed with a dramatic increase in systemic oxygen saturation alleviating the need for a surgical systemic-to-pulmonary artery shunt.

Catheterization↗
PubMed2006

An unusual late complication of axillobifemoral bypass graft: a case report.

Axillobifemoral bypass is a well-established surgical procedure performed in conditions that preclude direct arterial reconstruction due to aortic sepsis, aortoenteric fistula, or other hostile abdominal pathology or prohibitive surgical risk. The choice of prosthetic graft used is either knitted Dacron(R) or polytetrafluoroethylene, with equally good results. Although externally supported grafts reportedly yielded improvement in primary patency compared to historical controls, no consensus exists as to which demonstrates superiority over the other despite several retrospective studies. Complications are usually limited to the perioperative period, although late anastomotic disruption, graft thrombosis, axillary thromboembolism, pseudoaneurysm formation due to seat belt trauma, and hemorrhage or graft rupture have all been described. In addition to the above complications responsible for graft failure, perigraft infection, intimal hyperplasia, poor distal runoff, anastomotic fibrosis, and comorbid conditions may contribute to graft failure. We describe an unusual late complication of an axillobifemoral bypass graft whereby an organized thrombus within the layers of the bypass graft led to luminal compromise and, hence, attenuation of flow and resultant "failing graft."

Aged↗
PubMed1993

Some physical properties of an improved facial elastomer: a comparative study.

An attempt was made to evaluate some properties of clinical importance of a new facial elastomer, Cosmesil HC2. A comparative study versus Silskin II and Cosmesil SM4 was also carried out and took into account the effect of weathering after exposure to ultraviolet radiation. The results showed that Cosmesil HC2 is a resilient material and yet displays good tensile characteristics. The results also showed that weathering does not significantly affect Cosmesil HC2 elastomer's tear strength. The overall effect of irradiation was moderate in all materials tested.

Chemical Phenomena↗
PubMed1996

Serial doppler echocardiographic evaluation of bioprosthetic valves in the tricuspid position.

OBJECTIVES: This study sought to evaluate bioprosthetic valve dysfunction in the tricuspid position by serial Doppler echocardiography. BACKGROUND: Few reports on the long-term results of tricuspid valve replacement with bioprosthetic valves are evaluated by serial Doppler echocardiography. METHODS: Between September 1979 and December 1993, 95 patients underwent tricuspid valve replacement with bioprosthetic valves at our facility. Sixty patients who underwent serial Doppler echocardiographic examination at intervals of at least 2 years after operation were included in the final analysis. These patients were followed up from 1.5 to 13.0 years (mean 5.8 +/- 2.5). RESULTS: The actuarial rates of freedom from bioprosthetic valve stenosis and regurgitation at 10 years were 46% and 51%, respectively. The prevalence of bioprosthetic valve stenosis and regurgitation increased progressively in a linear manner beginning 1 or 2 years after tricuspid valve replacement. Right heart failure developed during follow-up in 20 of the 25 patients with bioprosthetic valve dysfunction. CONCLUSIONS: The long-term durability of bioprosthetic valves in the tricuspid position was substantially lower in our study than that reported in previous studies. Tricuspid bioprosthetic valve dysfunction increased progressively in a linear manner beginning 1 to 2 years after tricuspid valve replacement.

Actuarial Analysis↗
PubMed2001

Comparison of three types of fiber-reinforced composite molar crowns on their fracture resistance and marginal adaptation.

UNLABELLED: Three types of fiber-reinforced composite (FRC) molar crowns were tested on their fracture resistance and marginal adaptation under simulated oral stress conditions. Two glass fiber systems, one processed with a vacuum/pressure system, the other by manual fiber adaptation, and a polyethylene fiber system were evaluated. Every group consisted of 12 crowns. All crowns were luted adhesively on human molars and exposed to thermal cycling and mechanical loading (TCML: 6000 x 5 degrees C/55 degrees C; 1.2 x 10(6) x 50N; 1.66Hz). The marginal adaptation was evaluated through dye-penetration and analyzed semi-quantitatively with a scanning electron microscope. The fracture resistance was measured using a Zwick universal testing machine. The highest fracture resistance was observed on the glass-fiber systems (FibreKor/Sculpture 1875N +/- 596; Vectris/Targis 1726+/-542), though statistically, the polyethylene system (belleGlass/Connect 1388+/-620) was not significantly weaker. All systems exceeded the fracture resistance required to withstand the maximum masticatory forces expected in the molar region. The marginal adaptation generally had a tendency towards larger gaps after TCML. The crown/composite-cement bond deteriorated significantly after TCML with the manual fiber adaptation and the polyethylene fiber system. The cement/tooth bond strength depended on which composite-cement/dentin-adhesive system was used. CONCLUSION: The fracture resistance of molar crowns made of glass-fiber reinforced composite was higher than those of polyethylene fiber-reinforced composite crowns. However, there was no statistically significant difference. The marginal adaptation seems to depend on the fiber systems and composite-cement/dentin adhesive system used.

Analysis of Variance↗
PubMed1999

Morphological evaluation of a regurgitant orifice by 3-D echocardiography: applications in the quantification of valvular regurgitation.

The clinical evaluation of blood flow regurgitation through a heart valve or stenotic lesion is an unresolved problem. The proximal flowfield region has been the study focus in the last few years; however, investigators have failed to identify an accurate and reliable calculation scheme due to lack of geometric information about the shape and size of the regurgitating or stenotic orifice. Presented here is a superior method of calculation, by using three-dimensional (3-D) echocardiography combined with Doppler velocimetry. The geometric structure of the orifice in a regurgitating porcine prosthetic valve in vitro was formulated by 3-D image construction of sequentially obtained 2-D images. The velocity flowfield was accessed by color Doppler flow mapping (CD) and continuous-wave Doppler (CW). Two accurate methods of calculation of regurgitant variables were developed. The first method calculated peak regurgitant flow rate from CD and the second method calculated regurgitant flow volume from CW. Both methods showed excellent correlation with the corresponding true values from an electromagnetic flowmeter. The promising preliminary results in such a realistic porcine model indicate the possibility of establishing a routine procedure to be tested in the clinical setting.

Animals↗
PubMed2002

Crowns and other extra-coronal restorations: aesthetic control.

A pleasing dental appearance is the subjective appreciation of the shade, shape and arrangement of the teeth and their relationship to the gingiva, lips and facial features. Achieving such a pleasing appearance in our patients is not always easy but is critical, not least because our work is effectively on display and this has implications for patients' perceptions of our practice. To be successful, thorough assessment, careful planning and precise clinical execution is required. Every bit as important though, is good communication, both with the dental laboratory and particularly with the patient. In few areas of dentistry can effective communication be as critical as it is here.

Attitude to Health↗
PubMed1998

Comparison of computed tomography and duplex imaging in assessing aortic morphology following endovascular aneurysm repair.

BACKGROUND: Computed tomography (CT) has been used to assess patients following endovascular aneurysm repair to determine the need for secondary endoluminal or operative procedures. This prospective study compared CT and duplex imaging to evaluate aneurysm morphology following endoluminal aortic grafting. METHODS: Twenty patients were evaluated at regular intervals following successful endoluminal aneurysm repair. CT and duplex scanning were compared in their ability to determine aneurysm and aortic diameter, the presence of perigraft extravasation (endoleaks) and technical defects in the endograft. RESULTS: In 20 patients who were assessed 6 months after operation, duplex imaging identified four endoleaks (two early, two late; one proximal, three distal). In three cases, the aneurysm diameter progressively increased after operation. In patients with a thrombosed aneurysm sac, the aneurysm regressed at a median of 0.40 (range 0.13-0.8) cm per year. The CT findings were similar (median regression 0.43 (range 0-1.0) cm per year), although CT was unable to predict the site of the leak as accurately as duplex imaging. CT demonstrated that the diameter of the juxtarenal aorta increased following endografting. CONCLUSION: Duplex imaging is a less invasive, less costly alternative to CT in the follow-up of patients after endoluminal aortic surgery. Increase in size of the aneurysm sac following endovascular aneurysm repair strongly suggests the presence of an endoleak.

Aged↗
PubMedDate not supplied

Assessment of circulating blood volume in calves with a total artificial heart.

Measurement of the circulating blood volume (CBV) is essential to a proper understanding of the hemodynamic performance of total artificial hearts (TAHs). Recently, the authors employed CBV measurements using indocyanine green dye in calves with a TAH. The advantages of this method over previous methods using radionuclides include simplicity, low cost, and the capability of repeated and frequent measurements. Reproducibility of the measurements was demonstrated in three normal calves with a relative standard deviation of 3.9 +/- 2.4%. CBV was measured in eight calves with the Cleveland Clinic-Nimbus TAH and compared with that of seven calves that underwent mitral valve replacement. Small standard deviations in pre operative values in both TAH and mitral valve replacement groups demonstrated the precision of CBV measurements. Although there was no change in CBV in the mitral valve replacement group, CBV in the TAH group increased to more than twice the pre operative value after 2 weeks. Although the right atrial pressure increased similarly after TAH implantation, there was no correlation (r = 0.08) between the right atrial pressure and CBV, which suggested a possible inaccuracy in estimating CBV from the right atrial pressure. A negative correlation between the hematocrit value and CBV suggested that hemodilution might be one of the causes of anemia observed in our TAH animals.

Animals↗
PubMed2006

A continuous murmur.

A 61-year-old male with a history of a mechanical Bjork-Shiley aortic valve replacement in 1977 and repair of an ascending aortic root dissection in 1993, presented with a 2-week history of fatigue and exertional dyspnea. Echocardiography confirmed the presence of an aortic pseudoaneurysm with a fistulous connection between the aorta and right atrium, which subsequently underwent successful repair. Although there have been several cases describing the development of an aortic pseudoaneurysm after aortic dissection repair, our case is the first to describe an aorta-atrial fistula as a long-term complication of a previous aortic dissection repair.

Aortic Dissection↗
PubMed2004

Abdominal aortic aneurysm: contrast-enhanced US for missed endoleaks after endoluminal repair.

PURPOSE: To evaluate contrast material-enhanced ultrasonography (US) for depiction of endoleaks after endovascular abdominal aortic aneurysm repair (or endovascular aneurysm repair [EVAR]) in patients with aneurysm enlargement and no evidence of endoleak. MATERIALS AND METHODS: From November 1998 to February 2003, 112 patients underwent EVAR. At follow-up, duplex US and biphasic multi-detector row computed tomographic (CT) angiography were performed. In 10 patients (group A), evident aneurysm enlargement was observed, with no evidence of complications, at both CT angiography and duplex US. Group A patients, 10 men (mean age, 69.6 years +/- 10 [standard deviation]), underwent US after intravenous bolus injection of a second-generation contrast agent, with continuous low-mechanical index (0.01-0.04) real-time tissue harmonic imaging. Group B patients, 10 men (mean age, 71.3 years +/- 8.2) with aneurysm shrinkage and no evidence of complications, and group C patients, 10 men (mean age, 73.2 years +/- 6) with CT angiographic evidence of endoleak, underwent contrast-enhanced US. Digital subtraction angiography (DSA) was performed in groups A and C. Endoleak detection and characterization were assessed with imaging modalities used in groups A-C; at contrast-enhanced US, time of detection of endoleak, persistence of sac enhancement, and morphology of enhancement were evaluated. RESULTS: In group A, contrast-enhanced US depicted one type I, six type II, one type III, and two undefined endoleaks that were not detected at CT angiography. All leakages were characterized by slow and delayed echo enhancement detected at longer than 150 seconds after contrast agent administration. DSA results confirmed findings in all patients; percutaneous treatment was performed. In group B, contrast-enhanced US did not show echo enhancement; in group C, results with this modality confirmed findings at CT angiography and DSA. CONCLUSION: Contrast-enhanced US depicts endoleaks after EVAR, particularly when depiction fails with other imaging modalities.

Aged↗
PubMed2003

Comparison of transthoracic and intraoperative transesophageal color flow Doppler assessment of mitral and aortic regurgitation.

BACKGROUND: We examined the agreement between transthoracic echocardiography (TTE) and intraoperative prepump transesophageal echocardiography (TEE) in the assessment of left-sided regurgitant lesions and echocardiographic variables associated with grading discrepancies. METHODS: The TTE and prepump TEE studies of 54 patients undergoing aortic-valve replacement for aortic stenosis were reviewed. Agreement and correlation in assessment of aortic (AR) and mitral regurgitation (MR) severity were evaluated. RESULTS: There was no significant difference between mean TTE and prepump TEE grading of MR (0.23 +/- 0.19 vs. 0.21 +/- 0.15 jet area/area of the left atrium, p = 0.49), but the correlation between the two methods was weak (r = 0.40, p = 0.003), with an exact agreement of 54%. Prepump TEE tended to grade AR as more severe (mean grade 1.43 +/- 0.94 vs. 1.24 +/- 0.75, p = 0.058). The correlation between the two methods in AR assessment was fair (r = 0.70, p = 0.0001) with an agreement of 59%. For MR and AR grading, no significant correlations between valvular regurgitation severity and blood pressure differences between preoperative TTE and prepump TEE were found. In 17% of cases, discrepancies in identifying severe mitral or aortic valve regurgitation could have affected patient management. CONCLUSIONS: There is modest agreement in MR and AR assessment between TTE and prepump TEE. Cardiologists, cardiac surgeons, and anesthesiologists must be aware of differences between these methods when using prepump TEE to guide intraoperative decisions.

Aged↗
PubMedDate not supplied

Evaluation of the hemodynamic performance of St. Jude mitral prostheses: a pilot study by dobutamine-stress Doppler echocardiography.

In contrast to the widespread use of dobutamine stress Doppler echocardiography in the hemodynamic evaluation of the prosthetic valves in aortic position, it has been rarely, if ever, used for assessment of these valves in mitral position. Therefore, this pilot study was done to assess the hemodynamic performance of St. Jude prosthetic mitral valves (functional orifice area 25-31) with dobutamine-stress Doppler echocardiography. Twenty consecutive patients (13 women and 7 men, aged 23 to 42 years) who had undergone mitral valve replacement 6 to 4745 days previously and 16 healthy volunteers (5 women and 11 men, aged 18 to 42 years) underwent dobutamine-stress Doppler echocardiography. Dobutamine infusion was started at a rate of 5 microg/kg per minute and was increased by 5 microg increments at 3-minute intervals. Maximum and mean gradients as well as pressure halftime were measured at rest and at the end of each stage. The correlation between Doppler-derived variables versus the heart rate was assessed and a regression equation was obtained for each of them. A significant increase in blood pressure, heart rate, maximum and mean gradients was noted during dobutamine infusion in both groups. There was a significant positive linear correlation between the increasing transprosthetic mitral valvular maximum and mean gradients and the increments in the heart rate (G(max) = 4.47 + 0.093 [HR], r= 0.474, p<0.05) and (G(mean) = 3.0+0.003 [HR], r=0.2697, p<0.05), respectively, indicating the heart rate dependency of these parameters. Pressure halftime, on the other hand, had an inverse but linear relationship with the heart rate (PHT = 142 - 0.55 [HR], r= -0.577, p<0.05). Similar findings were found for the control group as well. Standard dobutamine-stress echocardiography can safely be performed in patients with St. Jude mitral valve prostheses. Single Doppler measurements of the pressure gradients and pressure halftime may yield erroneous conclusions regarding the function and size of these valves unless corrected for the patients simultaneous, online heart rate. The use of the regression equations obtained in this pilot study may help to partly overcome some of these difficult issues.

Adolescent↗
PubMed1998

The clinical longevity of porcelain veneers: a 48-month clinical evaluation.

The authors evaluated the clinical longevity of a brand of porcelain veneers and the accompanying cementation system. Fifty-nine porcelain veneers were prepared and placed in 12 patients by one practitioner and evaluated by two evaluators using modified Ryge criteria at baseline and 12 months. Fifty-three veneers were evaluated similarly at 48 months. Plaque index and gingival index scores were recorded as well. At 48 months, the veneers had stable color, all margins were clinically acceptable, there was no secondary caries and the patients reported no sensitivity.

Adhesives↗
PubMed1997

Histologic aspects of the bone and soft tissues surrounding three titanium non-submerged plasma-sprayed implants retrieved at autopsy: a case report.

The authors report the histological features found around three non-submerged titanium plasma-sprayed implants retrieved, after a 10-month loading period, from an autopsy case. At the time of implant insertion, the clinician had noted a wide vestibular dehiscence of the central implant, and it was decided to use a bioabsorbable membrane for guided bone regeneration in this area. After specimen processing, it was possible at low magnification to observe that in the most vestibular slides, the central implant was almost completely surrounded by connective tissue, while in the most lingual slides, the quantity of bone around the implant tended to increase. The other two implants had a bone-implant contact percentage of about 60%. Only in a few areas was mineralized bone in direct contact with the metal surface, while around the major portion of the implant perimeter a layer of unmineralized, red-stained, osteoid material was present. No inflammatory infiltrate was present in the epithelium and in the supracrestal connective tissues. The fibers of this tissue had a different orientation: in the most coronal portion of the implants (smooth surface), they tended to run parallel implant's surface, while in the most apical region (plasma-sprayed surface), they tended to be arranged in a perpendicular fashion. These results, in man, were strikingly similar to those previously reported in dogs and monkeys.

Absorption↗
PubMed1995

Mastique laminate veneers: results after 4 and 10 years of service.

The purpose of the present study was to evaluate the clinical quality over 4 years and the longevity over 10 years of 77 Mastique laminate veneers (DeTrey, Dentsply). The veneers were bonded to incisors and canines with a light-cured composite resin, using the acid-etch technique, and examined every 1/2 year in accordance with USPHS criteria. Anatomic form and marginal adaptation were rated excellent in more than 50% of the veneers throughout the study. Moderate surface wear was seen in most of the veneers after 4 years of service. Marginal discoloration and color match were recorded as not acceptable in 20% of the veneers at the 4-year control. No significant difference was found in the gingival index between veneer and control teeth. The cumulative retention rate was 40% after 4 years and 20% at the 10-year recall. Owing to the high frequency of spontaneous loss, Mastique laminate veneers cannot be recommended as permanent restorations.

Acid Etching, Dental↗
PubMed2004

Application of alumina coping to porcelain laminate veneered crown: part 1 masking ability for discolored teeth.

A densely sintered high-purity alumina has been successfully utilized as a coping for all-ceramic crown. In order to apply the alumina coping to the porcelain laminate veneer restoration for the discolored teeth, the present study evaluated its masking ability when it was thinner than the proposed thickness for the crown. Colorimetric examination was performed on white and black backgrounds for the 0.7 mm thick porcelain laminate veneer with 0.40 or 0.25 mm thick alumina coping and 0.7 mm thick porcelain without coping. With the presence of the coping, the porcelain appeared significantly lighter. Judging from the calculated color differences delta E and the literature, it was suggested that the masking ability of the alumina coping would be sufficient with a 0.25 mm thickness for the porcelain laminate veneer for heavily discolored teeth.

Aluminum Oxide↗