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At least 1,549 records · Page 86Linked to original sources
PubMed1997

Role of inverted buttoned device in transcatheter occlusion of atrial septal defects or patent foramen ovale with right-to-left shunting associated with previously operated complex congenital cardiac anomalies.

Feasibility, safety, and effectiveness of transcatheter occlusion of atrial septal defect (ASD) with the buttoned device has been demonstrated. Despite its effectiveness in occluding secundum ASD with left-to-right shunt and patent foramina ovalia, presumably responsible for paradoxic embolism, it has limitations in effectively occluding ASD with evident right-to-left shunts. Therefore, the device was modified so that the square-shaped occluder component of the device is on the right atrial side, the inverted buttoned device. This study determines the feasibility, safety, and effectiveness of inverted buttoned device occlusion of atrial defects with right-to-left shunts. During a 17-month period ending August 1996, 12 patients, aged 1.6 to 39.0 years, underwent occlusion of residual ASD after repair of pulmonary atresia/stenosis with intact ventricular septum (n = 5), modified or fenestrated Fontan for tricuspid or pulmonary atresia (n = 5), and double-inlet left ventricle (n = 2). The systemic arterial oxygen saturation increased (p <0.001) from 82 +/- 7% (range 72% to 90%) to 94 +/- 3% (range 88% to 98%). There was no change in heart rate or cardiac index measured by Fick. Right atrial pressure increased by 1 to 4 mm in 5 of 12 patients (42%). There was trivial (n = 5) or no (n = 7) residual shunt by color Doppler study. Six- to 18-month (median 12) follow-up in all 12 patients revealed stable oxygen saturations (92 +/- 3%) by pulse oximetry. Color Doppler studies revealed small (n = 1), trivial (n = 1), or no (n = 10) residual shunt at follow-up. Based on these data, it is concluded that transcatheter occlusion of ASD with right-to-left shunts with inverted buttoned device is feasible in relieving arterial hypoxemia. Further clinical trials in a larger number of patients and careful evaluation of follow-up results are indicated to examine its safety and longer term effectiveness.

Adolescent↗
PubMed1990

[A clinical trial with a new silicone implant by Silikon Optik].

A new silicone IOL is described which was implanted in 57 eyes, in 50 cases following phacoemulsification through a 4.2-4.8 mm incision. The principal advantages of this IOL are (a) faster visual rehabilitation, because postoperative astigmatism is reduced and more stable, and (b) less glare and color alteration than after implantation of PMMA lenses. These optical advantages may be due to the non-occurrence of optic decentration, the absence of positioning holes, the biconvex optic, the fact that the surface is less reflective than that of PMMA, and the Tyndall effect of the lens material. The only disadvantage of this lens as compared to PMMA lenses is that the YAG laser is more likely to produce pitting or cracks during capsulotomy.

Adolescent↗
PubMed1991

Color-flow duplex criteria for grading stenosis in infrainguinal vein grafts.

Color-flow duplex scanning of infrainguinal vein bypasses was used to identify failing grafts. Several duplex parameters were compared to determine their value in identifying and quantifying the degree of stenosis. Intraarterial digital subtraction angiography was used as the "gold standard" to determine the severity of the stenosis. The goal of this study was to identify specific color-flow duplex criteria for grading stenotic lesions. After a retrospective analysis some of these parameters were prospectively validated. The surveillance protocol required a color-flow duplex scan every 3 months for the first year and every 6 months during the second year. One hundred sixteen vein grafts in 112 patients were studied. Forty-three stenoses were identified and classified into categories from 30% to 49%, 50% to 69%, and 70% to 99% diameter reduction. These stenoses were identified in either the bypass graft or adjacent inflow or outflow arteries. Failing grafts were evaluated further by intraarterial digital subtraction angiography. Patients with normal appearing bypasses (without suspected stenotic lesions) had intravenous digital subtraction angiography. The five duplex parameters that were studied included the following: (1) graft peak systolic velocity (PSV-graft), (2) the maximum peak systolic velocity (at the site of a stenosis or in normal grafts at the narrowest segment of the bypass) (PSV-max), (3) the ratio between PSV-graft and PSV-max, (PSV-index), (4) end-diastolic velocity (EDV) at a stenosis or from narrowest graft segment, (5) color-flow image diameter measurements. For discrimination of different degrees of stenosis, threshold values of these parameters were calculated by receiver operating characteristic analysis. Diameter reduction measured by color-flow imaging was best to identify all stenotic lesions greater than 29% (sensitivity 88%, specificity 99%). Peak systolic velocity-index proved optimal identification of stenoses greater than 49% (sensitivity 89%, specificity 92%), and 70% to 99% stenoses were associated with increased EDV (sensitivity 91%, specificity 100%). The PSV-index criteria were then validated prospectively in a separate group of vein grafts. The data support the value of surveillance of femorodistal vein grafts and demonstrate that calculation of the degree of graft stenosis is feasible.

Angiography, Digital Subtraction↗
PubMed2006

Is now the time to purchase an in-office CAD/CAM device?

In-office CAD/CAM is a reality. It allows fabrication of tooth-colored inlays and onlays, crowns and veneers in one appointment. It is especially well-suited to dentists who accomplish many single-tooth or single-quadrant restorations. As with any new technology, its cost is high, but using it can be financially feasible. Clinical and basic science investigations have resulted in positive findings on the concept. There are some significant advantages and several disadvantages. In-office CAD/CAM works well for many dentists, but practitioners should evaluate it carefully before accepting it, as it is not for everybody.

Ceramics↗
PubMed1993

Development and evaluation of a pliable biological valved conduit. Part II: Functional and hemodynamic evaluation.

Many congenital cardiac malformations may require a valved conduit for the reconstruction of the right ventricular outflow tract. In spite of many endeavors made in the last 25 years, the clinical results of right ventricular outflow tract reconstruction with currently available valved conduits are still not satisfactory. Specific problems encountered clinically include suboptimal hemodynamic performance, conduit kinking or compression, and fibrous peeling from the luminal surface. To address these deficiencies, we undertook the development of a biological valved conduit: a bovine external jugular vein graft with a retained native valve cross-linked with a diglycidyl ether (DE). This study, using a canine model, was to evaluate the functional and hemodynamic performance of this newly developed valved conduit. Three 14 mm conduits, implanted as bypass grafts, right ventricle to pulmonary artery, were evaluated. The evaluation was conducted with a noninvasive color Doppler flow mapping system at pre-implantation, immediately post implantation, one- and three-months post implantation, and prior to retrieval (five-months post implantation). The two-dimensional tomographic inspection of the leaflet motion at various periods post implantation showed that the valvular leaflets in the DE treated conduit was quite pliable. No cardiac failure or valvular dysfunction was observed in any of the studied cases. The color Doppler flow mapping study demonstrated that the valve in the DE treated conduit was competent, with no conduit kinking or compression observed in any of the three cases. The spectral Doppler velocity study evidenced that the transvalvular pressure gradients of the DE treated conduit were minimal as compared to those of the currently available conduits. In conclusion, from the functional and hemodynamic performance points of view, this newly developed valved conduit is superior to those currently available.

Animals↗
PubMed2004

The artificial silicon retina microchip for the treatment of vision loss from retinitis pigmentosa.

OBJECTIVE: To determine the safety and efficacy of the artificial silicon retina (ASR) microchip implanted in the subretinal space to treat vision loss from retinitis pigmentosa. METHODS: The ASR microchip is a 2-mm-diameter silicon-based device that contains approximately 5000 microelectrode-tipped microphotodiodes and is powered by incident light. The right eyes of 6 patients with retinitis pigmentosa were implanted with the ASR microchip while the left eyes served as controls. Safety and visual function information was collected. RESULTS: During follow-up that ranged from 6 to 18 months, all ASRs functioned electrically. No patient showed signs of implant rejection, infection, inflammation, erosion, neovascularization, retinal detachment, or migration. Visual function improvements occurred in all patients and included unexpected improvements in retinal areas distant from the implant. MAIN OUTCOME MEASURES: Subjective improvements included improved perception of brightness, contrast, color, movement, shape, resolution, and visual field size. CONCLUSIONS: No significant safety-related adverse effects were observed. The observation of retinal visual improvement in areas far from the implant site suggests a possible generalized neurotrophic-type rescue effect on the damaged retina caused by the presence of the ASR. A larger clinical trial is indicated to further evaluate the safety and efficacy of a subretinally implanted ASR.

Aged↗
PubMed2005

Molecular and imaging techniques for bacterial biofilms in joint arthroplasty infections.

Biofilm formation on surfaces is an ancient and integral strategy for bacterial survival. Billions of years of adaptation provide microbes with the ability to colonize any surface, including those used in orthopaedic surgery. Although remarkable progress has been made in the treatment of orthopaedic diseases with implanted prostheses, infection rates remain between 1% and 2%, and are higher for revision surgeries. The chronic nature of implant infections, their nonresponsiveness to antibiotics, and their frequent culture negativity can be explained by the biofilm paradigm of infectious disease. However, the role of biofilms in orthopaedic implant infections and aseptic loosening is controversial. To address these issues, we developed molecular diagnostic and confocal imaging techniques to identify and characterize biofilms associated with infected implants. We designed PCR and reverse transcription (RT)-PCR-based assays that can be used to detect bacterial infections associated with culture-negative joint effusions that distinguish between physiologically active Staphylococcus aureus and Staphylococcus epidermidis. Using clinical isolates of Pseudomonas aeruginosa, we constructed a series of reporter strains expressing colored fluorescent proteins to observe biofilms growing on 316L stainless steel and titanium orthopaedic screws. Three-dimensional structures of Pseudomonas aeruginosa and staphylococci biofilms growing on the screws were documented using confocal microscopy. The application of these tools for clinical diagnosis and biofilm research in animal and in vitro models is discussed.

Arthroplasty↗
PubMed2005

Transcatheter device closure of interatrial septal defects in patients with hypoxia.

BACKGROUND: There has been growing interest in transcatheter closure of interatrial septal defects (IASDs) for a variety of indications, but reports are limited in patients with hypoxia from right-to-left shunting. METHODS: Between August 2000 and October 2004, 181 patients were referred to our institution for elective closure of a patent foramen ovale (PFO) or atrial septal defect (ASD). Among these patients, 10 (5.5%) underwent closure for hypoxia due to persistent or intermittent right-to-left shunting. Clinical evaluation, including echocardiography with color Doppler and agitated saline, was performed in all patients to determine the degree of right-to-left shunting. Defects were closed with Amplatzer (n = 4) or Cardioseal (n = 6) devices, under transesophageal (TEE) or intracardiac echocardiography (ICE) guidance. RESULTS: Mean age was 62.7 years (range: 31-88 years) with 70% female. Characteristics for closure included four patients with persistent hypoxia and six with intermittent hypoxia, including two with platypnea-orthodeoxia syndrome. All patients had echocardiography showing moderate (n = 6) or severe (n = 4) shunting. Patients had significant comorbidities, including chronic lung disease requiring supplemental oxygen (n = 5) and congestive heart failure (n = 2). TEE guidance was used in three patients, and ICE was performed in the remainder. Mean closure device diameter was 27 mm. Mean preprocedural arterial oxygen saturation of 86.7% improved to 95.9% immediately after closure, with color Doppler and agitated saline revealing the absence of (n = 5) or mild (n = 5) shunting. In-hospital major complications were limited to one patient with a transient ischemic attack after an initially unsuccessful closure attempt. CONCLUSIONS: Percutaneous closure of IASDs in a heterogeneous group of patients with hypoxia can be safely and effectively performed. The procedure results in immediate arterial saturation improvement and reduced right-to-left shunting.

Adult↗
PubMedDate not supplied

A newly developed porcine heart valve bioprosthesis fixed with an epoxy compound. An experimental evaluation.

Concerns with currently available bioprostheses are calcification, long-term durability, and functional and hemodynamic performance. It has been well known that these concerns are all more or less related to the fixatives, glutaraldehyde or formaldehyde, used in preserving bioprostheses. To address these concerns, we undertook the development of a porcine bioprosthesis fixed with an epoxy compound. It was discovered that the porcine leaflets fixed with the epoxy compound appeared more natural than those preserved with glutaraldehyde. The performance of this newly developed epoxy compound bioprosthesis (three samples) was evaluated in a juvenile sheep model. The results were compared to those of its glutaraldehyde counterpart (three samples). Two-dimensional echocardiographic inspection of the valvular leaflet motion indicated that the epoxy compound leaflets were more pliable than their glutaraldehyde counterparts. In addition, the epoxy compound valve appeared to open more widely than the glutaraldehyde valve. Color Doppler flow mapping demonstrated that the blood flow distal to the epoxy compound valve was slightly broader than that observed distal to the glutaraldehyde valve. Moreover, at retrieval, less calcium and pannus ingrowth were observed in the epoxy compound valve than its glutaraldehyde counterpart. The results of this preliminary evaluation indicated that the performance of this newly developed epoxy compound valve was at least equivalent to its glutaraldehyde counterpart, if not better.

Animals↗
PubMed2001

Homograft pulmonic stenosis after the Ross procedure: evaluation of the stenotic valve area by proximal isovelocity surface area (PISA).

The proximal isovelocity surface area (PISA) technique has been used to evaluate valvular regurgitant flow, regurgitant orifice area, and stenotic valve area. This report shows the usefulness of this Doppler technique in quantifying the stenotic valve area of a pulmonic valve homograft prosthesis after the Ross procedure. The patient was a 35-year-old man who had a Ross procedure 3 years earlier for aortic stenosis, which included replacement of the pulmonic valve with a cryopreserved homograft pulmonic valve. With an aliasing velocity set at 40 cm/s and a PISA radius of 1.1 cm, the pulmonic valve area was calculated as follows: Pulmonic valve peak flow rate = 2 x3.14 x1.12 x40 = 304 mL/s; Pulmonic valve area = Peak flow rate / Peak velocity = 284/350 = 0.87 cm2.

Adult↗
PubMed1992

Postprandial augmentation of portal hepatic inflow after prosthetic H-graft portacaval shunt.

Encephalopathy after portasystemic shunting generally occurs after eating. After partial portal decompression, encephalopathy is uncommon, presumably because of associated portal hemodynamics. However, after partial shunting, the changes in portal venous hemodynamics that occur with eating are unknown. With this in mind, 11 nonencephalopathic adults were studied more than 1 year after 8-mm H-graft portacaval shunt (PCS). The studies utilized color flow duplex ultrasound to determine the changes in portal vein (PV) and inferior vena cava blood flow that occur with eating a standardized meal. Following H-graft PCS, there is increased blood flow in the inferior vena cava after eating, particularly cephalad to the H-graft PCS, implying increased flow through the prosthetic shunt. Eating also increases hepatopedal blood flow in the PV distal to the H-graft PCS. Postprandial increases in hepatopedal portal blood flow may play an important role in avoiding encephalopathy after H-graft PCS.

Blood Flow Velocity↗
PubMed1982

Evaluating cosmetic results in maxillofacial prosthetics.

Fifty-two patients with maxillofacial prosthetic restorations answered questionnaires to measure their feelings of well being. Their overall scores averaged 38.6%. Subsequently, three independent observers reported their evaluation for each patient, yielding a combined improvement score of 35.1%. The apparently low figures reflect the strict criteria used. Men patients showed a greater response than women patients both in subjective questionnaire scores and objective evaluation rating. Greater improvement was reported in younger patients, yet the objective evaluators found better success in the older age group. The original etiology of the maxillofacial defect, i.e., traumatic injury, congenital malformation, or surgical tumor excision was the most important factor in the evaluation. Questionnaire scores were similar in all categories. However, the objective evaluation, especially that of the sculptor, who judged color slides alone, was significantly higher in the injury group than in cancer patients. Apparently, the inner desperation of many cancer patients is apparent in their facial appearance even after complete prosthetic rehabilitation. Such patients deserve greater psychologic attention during their treatment. Prosthodontists should realize their tendency to be hypercritical of their own treatment results. Their constant striving for improvement in their treatment results leads them to belittle their achievements and to underestimate their success. Public opinion, as represented by the artists, is significantly more enthusiastic about maxillofacial prosthetic achievements.

Adolescent↗
PubMed2006

T lymphocytes in implant-associated posttraumatic osteomyelitis: Identification of cytotoxic T effector cells at the site of infection.

In implant-associated posttraumatic osteomyelitis, a massive infiltration of leukocytes into the infected site is seen. As described previously, the most infiltrated cells were highly activated polymorphonuclear neutrophils. In addition, a considerable T-cell infiltrate was noted. Whereas our previous work was mainly concerned with the phenotypical and functional characterization of the polymorphonuclear neutrophils, we now analyzed T lymphocytes of 32 patients with implant-associated posttraumatic osteomyelitis. We found evidence for an expansion of CD8 T cells in the peripheral blood of the patients and for an infiltration of these cells into the infected site. Further analysis of the surface-receptor pattern by three-color cytofluorometry revealed that the majority of these cells belonged to the cytotoxic-effector phenotype. Of note is that cytotoxic T cells are generally associated with virus infection. Thus, the detection of those cells in patients with bacterial infection was rather unexpected and points to a novel, not yet appreciated, role of CD8 T cells also in the defense of bacterial infections.

Adolescent↗
PubMed2004

[Endovascular treatment of vertebral artery origin stenosis in high risk patients].

PURPOSE: Atherosclerotic stenosis of the vertebrobasilar system most commonly occurs at the vertebral artery origin. Stenting of these stenotic lesions in combination with antithrombotics with or without anticoagulants is a safe and effective treatment method. The purpose of this study is to present the results of vertebral artery origin stenting in 14 high-risk patients. MATERIALS AND METHODS: Significant vertebral artery origin stenosis was treated with primary stenting in 14 patients, aged between 58 and 74 years (mean, 66+/-5.3 years). Eleven patients were male, and three were female. Vertebral artery stenosis was detected in eight patients prior to coronary artery surgery, and in six patients after a posterior system stroke or during evaluation of a vertebrobasilar insufficiency. All stenosis were successfully treated with stent placement. Except one patient who had a left posterior cerebral artery infarction, all patients had an uneventful procedure without any complication. Third-month and sixth-month clinical and color Doppler follow-up examinations were available in ten patients, and 12th-month control angiography performed in three patients did not show stent restenosis. None of the patients had new neurologic deficit during the follow-up. CONCLUSION: Vertebral artery origin stenoses are one of the most common causes of vertebrobasilar stroke. In the presence of concomitant cerebral artery stenosis or systemic disorders, patients are under high risk even if they are on medical therapy. Primary stenting combined with medical treatment is a safe and effective treatment modality.

Aged↗
PubMed2002

[Interventional occlusion of interatrial communication after modified Fontan operation].

UNLABELLED: After modified Fontan operations various communications between the systemic and pulmonary venous returns may cause persistent or increasing postoperative cyanosis. Interventional closure of these right-to-left shunts may be necessary to eliminate hypoxemia and to reduce the risk of paradoxical embolic complications. PATIENTS AND METHODS: Eighteen patients with a mean age of 5.6 +/- 4.1 (2.5-17.5) years underwent interventional closure of a right-to-left shunt 17.4 +/- 15.8 (3-60) months after a modified Fontan operation. After test balloon occlusion fenestrations were closed in 13 patients using an Amplatzer Septal occluder (n = 7), a Rashkind PDA occluder (n = 3), a CardioSeal umbrella (n = 1) and detachable coils (n = 2). Residual leaks at the suture lines between the interatrial patch and the right atrial wall were closed using detachable coils and a Rashkind PDA occluder in 2 and 1 patients, respectively. In 3 patients intracardiac venous collateral channels were closed by means of detachable coils. RESULTS: The mean aortic oxygen saturation increased from 85 +/- 4.5 (70-89)% to 91.4 +/- 2.8 (83-95)% (p < 0.001) breathing room air and the mean tunnel pressure rose from 10.7 +/- 1.8 (6-14) mmHg to 12.1 +/- 2.4 (6-16) mmHg (p < 0.001). Calculated Qs decreased from 5.15 +/- 2.1 (2.1-11.3) l/min/m2 to 3.6 +/- 1.0 (1.8-5.6) l/min/m2 (p < 0.001). Mixed venous saturation (66.4 +/- 7.4% vs 65 +/- 7%) and mean systemic arterial pressure (73 +/- 8 mmHg vs 73 +/- 9 mmHg) remained unchanged. In one patient an additional leak of the tunnel could not be closed because of an increase to more than 18 mmHg of the mean pressure in the lateral tunnel during balloon test occlusion. In 2 patients residual leaks after umbrella and coil occlusion of a fenestration and an additional venous collateral channel were closed by means of coils after 16 and 21 months, respectively. At a follow-up of 42 +/- 23 (7-99) months, mean oxygen saturation measured by pulse oxymetry was 93 +/- 2 (90-97)%. In 2 patients color-coded Doppler echocardiography revealed a minimal residual right-to-left shunt. In 2 patients contrast echocardiography demonstrated the additional presence of intrapulmonary fistulas. All patients remained free from device migration, thromboembolic events and hemolysis. CONCLUSION: After modified Fontan operations various right-to-left shunts between the systemic and pulmonary venous returns can be successfully closed using umbrella devices or coils to eliminate cyanosis and to reduce the risk of paradoxical embolism.

Adolescent↗
PubMed1992

Quantitation of the turbulent stress distribution downstream of normal, diseased and artificial aortic valves in humans.

Damage to blood corpuscles seems to be related to the magnitude and exposure time of the turbulent shear stresses (TSS). According to in vitro studies the critical TSS level for lethal erythrocyte and thrombocyte damage is 150-400 N/m2, for exposure times within physiological ranges. To study the distribution of TSS in the human ascending aorta, a hot-film anemometer needle probe was used to register blood velocities at 41 evenly distributed measuring points in the cross-sectional area 5-6 cm downstream of the aortic annulus. Measurements were made in the ascending aorta after normal aortic valves (prior to coronary bypass surgery), after stenotic aortic valves, and after implantation of either St. Jude Medical or Starr Edwards Silastic Ball valves. Three-dimensional visualization of velocity profiles were performed and Reynolds normal stresses (RNS) were calculated within 50-ms overlapping time windows in systole. By coordinating the mean RNS for each time window and for all 41 measuring points, 2-dimensional color-coded mapping of the RNS distribution was made. Based on the velocity profiles and the RNS distribution a relative blood damage index (RBDI) was calculated to incorporate the magnitude and exposure time for RNS in the entire cross-sectional area into one parameter. Turbulent shear stresses were estimated by using a previously determined correlation equation between RNS and TSS. After normal aortic valves, RNS was below 4 N/m2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1997

Mycotic aneurysm of the bilateral tibioperoneal trunks associated with bacterial endocarditis: a case report.

Since antibiotics have been widely used in the treatment of bacterial endocarditis, mycotic aneurysms caused by septic emboli have become extremely rare. We report the case of a 34-year-old man who had mycotic aneurysms in the tibioperoneal trunks of both legs six weeks after he had a mitral valve replacement due to Streptococcus viridans endocarditis. Color Doppler sonography was used to diagnose pseudoaneurysms in both legs. Surgical treatment included the closures of the orifices of both aneurysms in both legs and arterial reconstructions were not required. In the literature, however, the location of mycotic aneurysms in peripheral arteries related to endocarditis were usually reported to be in the upper extremities or femoral arteries. Thus, we present the extremely rare case of mycotic aneurysms because the aneurysms occurred in the infrapopliteal vessel and developed in both legs.

Adult↗
PubMed1996

Masticatory function of postoperative tumor patients rehabilitated with osseointegrated implants.

PURPOSE: This study determined the level of masticatory function that can be achieved with osseointegrated implants in postoperative tumor patients. PATIENTS AND METHODS: Masticatory function was evaluated in 15 postoperative tumor patients with implants, 22 nontumor patients with implants, and 15 natural dentate controls. The area of occlusal contact was evaluated with a pressure-sensitive, color-developing bite sheet analyzed by computer. Chewing performance was evaluated by a low-adhesive, color-developing, chewing-gum system. RESULTS: Subjects in the tumor group had load-bearing tooth contacts similar to those of the natural dentate controls and nontumor implant patients. Continuity of the mandible was essential to sustain occlusal load. The presence of the hypoglossal nerve was the main factor in determining restoration of chewing performance. CONCLUSIONS: Surgical efforts to preserve the mobility of the residual tongue and prosthetic approaches to restore impaired mobility to as great an extent as possible are especially important for better functional rehabilitation of patients who have defects of the hypoglossal nerve.

Adult↗