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At least 1,189 records · Page 66Linked to original sources
PubMed1998

Surveillance of patients after abdominal aortic aneurysm repair with endovascular grafting or conventional treatment.

At Nuremberg Southern Hospital we have been using endovascular therapy for aortic aneurysms for the past 3 years. Between August 1994 and August 1997, 193 patients with infrarenal aortic aneurysms were treated with endovascular stent grafts. Besides using commercially available modular systems of the Stentor type (MinTec/Vanguard*, Boston Scientific) we also participated in a multicenter study implanting EGS devices (EVT in 65 patients). Follow-up examinations must strive to detect thrombotic complications as well as endoleaks with high sensitivity and specificity. To avoid aneurysm rupture significant increase in aneurysm diameter must be detected in a timely fashion to select patients for additional corrective endovascular procedures or conversion to open surgical therapy. A close follow-up regimen therefore is absolutely mandatory for all patients undergoing endovascular aortic grafting, particularly when new prosthetic devices are being introduced. Prosthetic devices that have been adequately tested using controlled study designs and are commercially available may be followed-up using a standardized follow up scheme as delineated. Particularly during the first postoperative year color duplex with use of an intravenous ultrasound enhancing agent has been used successfully to detect even minor endoleaks originating from retrograde perfusion via aortic side branches (lumbar or inferior mesenteric artery). Only patients with documented endoleaks or suspected outflow obstruction requiring further intervention need to undergo diagnostic arteriography. After conventional aneurysm repair yearly duplex scans are usually sufficient to follow the normal patient. Patients who have undergone endovascular therapy, however need to be followed much closer using duplex as well as abdominal CT scans. This will logically result in significantly higher follow up costs. Periinterventional costs of endovascular aortic reconstruction currently exceed those of conventional aortic repair by approximately 50%. Given the current health care finance situation it is questionable whether endovascular therapy of abdominal aneurysm will become standard practice in Germany.

Aged↗
PubMed1996

Mechanisms of venous leakage: a prospective clinicopathological correlation of corporeal function and structure.

PURPOSE: We investigated the pathophysiology of structurally based corporeal veno-occlusive dysfunction. MATERIALS AND METHODS: We prospectively evaluated 24 impotent patients (mean age plus or minus standard error 46 +/- 3 years) who had exposure to vascular risk factors and/or disorders inducing diffuse trabecular structure alterations and who underwent penile prosthesis insertion. Preoperative indexes of veno-occlusive function (flow to maintain, venous outflow resistance and pressure decay measurements using repeat dosing pharmacocavernosometry) were correlated with postoperative erectile tissue computer assisted color histomorphometry (percent trabecular smooth muscle to total erectile tissue area). To develop further study findings and correlate histomorphometric findings with molecular biological properties molecular biological studies (ribonuclease protection analysis, reverse transcription-polymerase chain reaction assay for expression of transforming growth factor-beta 1 messenger [m] ribonucleic acid [RNA] and protein affinity labeling techniques for specific transforming growth factor-beta receptors) were performed in representative patients with high (39 to 43%), intermediate (30 to 37%) and low (13 to 29%) trabecular smooth muscle content (normal 42 to 50%). RESULTS: Flow to maintain, venous outflow resistance and pressure decay values significantly correlated with trabecular smooth muscle cell content (r = -0.89, 0.82 and -0.85, respectively). In the high, intermediate and low smooth muscle content subgroups flow to maintain, venous outflow resistance and pressure decay values were 1 to 5, 9 to 30 and 50 to 120 ml. per minute, 17 to 84, 3 to 9 and 1 to 2 mm. Hg/ml. per minute, and 40 to 60, 48 to 80 and 110 to 120 mm. Hg decrease in 30 seconds from 150 mm. Hg, respectively. There were no significant differences in patient age or prevalence of risk factors among the 3 subgroups. Patients representative of all 3 subgroups had transforming growth factor-beta 1 mRNA, auto-induction of transforming growth factor-beta 1 mRNA and induction and/or increased availability of all 3 types of transforming growth factor-beta receptors. CONCLUSIONS: The pathophysiology of structurally based corporeal veno-occlusive dysfunction is related to elevated corporeal connective tissue content. Based on our data and those in the literature corporeal fibrosis is hypothesized to develop secondary to abnormalities in the regulation of normal collagen synthesis and degradation, most likely associated with adverse influences of chronic ischemia.

Adult↗
PubMed1991

[Regurgitation jets in mitral prosthesis studied using transesophageal echocardiography].

STUDY OBJECTIVE: To analyze the regurgitant jets of mitral valve prostheses studied by transesophageal echocardiography. DESIGN: Prospective study of patients with mitral prostheses with or without suspicion of dysfunction. SETTING: Patients referred to the Echocardiology Department of the Instituto de Cardiologia in Madrid, some as outpatients. PATIENTS AND INTERVENTIONS: Twenty five patients with mitral valve prostheses (5 biological, 7 St Jude, 12 Bjork Shiley and 1 Hall Kaster). Ten male patients and fifteen female, mean age 50 years. Five also had aortic valve prostheses. In only 5 there was a suspicion of dysfunction. The transthoracic echos were done with phased array transducers and the transthoracic with 2.5 (18 patients) or 5 MHz (7 patients) transducers coupled to a commercial echocardiographer. The presence of regurgitant jets was looked for, as well as their origin, maximal area and length, their type and degree of turbulence. MAIN RESULTS: Only 3 mitral regurgitations were noticed by transthoracic echocardiography. All the mechanical prostheses and 80% of the biological ones had regurgitant jets by transesophageal echocardiography. The tilting disc prostheses had two physiological jets, the St. Jude 2, 3, or exceptionally only one central jet. The biological prostheses had one central regurgitant jet, that was smaller than those from the mechanical prostheses (p less than 0.05). There were ten malfunctioning prostheses (5 Bjork Shiley, 3 St Jude and 2 biological). The diagnosis of dysfunction was based on the abnormal origin of the jet (9 cases) or just simply on the characteristics of the regurgitation (turbulence). Four patients were submitted to surgery, all with dysfunctioning prostheses. CONCLUSIONS: Transthoracic echocardiography has a low sensitivity for detecting the regurgitant jets of mitral prostheses. All mechanical prostheses and 80% of biological ones have regurgitation by transesophageal echocardiography. The area and length of the jets are not so different between normal and malfunctioning prostheses in order to separate them. The abnormal jets are recognised because of their abnormal origin and/or their characteristics, with formation of mosaic in color coded Doppler echocardiography.

Adult↗
PubMed1999

The stentless quadrileaflet bovine pericardial mitral valve: echocardiographic assessment.

BACKGROUND AND AIMS OF THE STUDY: Recently, a stentless chordally supported quadrileaflet mitral valve (QMV) bioprosthesis made of selected tanned bovine pericardium treated to minimize calcification, has become available for clinical trial. The aim of this study was to report both the echocardiographic appearance and hemodynamic performance of this valve by means of echocardiography. METHODS: The QMV was implanted in 22 patients (mean age 38 +/- 12 years) requiring isolated mitral valve replacement for valve lesions not deemed suitable for repair. Echocardiography was performed pre-operatively, and at one and three months postoperatively. Transthoracic echocardiography (TTE) was used to monitor mean instantaneous pressure gradient as calculated from the long modified Bernoulli equation, cardiac index (CI), pressure half-time and effective orifice area (EOA) using the Hatle and continuity equations. Regurgitation patterns were sought by color Doppler transesophageal echocardiography in all valves intraoperatively following valve implantation, and by TTE in the outpatient clinic at follow up. RESULTS: After a mean follow up of 8.3 months (range: 1 to 18 months), all patients were well and symptomatically improved. At three months postoperatively, the mean pressure gradient ranged from 1.7 to 2.2 mmHg. The EOA was larger using the Hatle as compared with the continuity equation (2.4 +/- 0.7 cm2 versus 1.8 +/- 0.5 cm2, respectively; p < 0.005). Mitral regurgitation was trivial in 77% and mild in 14% of patients at 3 months after surgery; moderate mitral stenosis was noted in one patient. The CI improved significantly postoperatively (p < 0.005), and left ventricular function was maintained. CONCLUSIONS: The hemodynamic performance of this novel prosthesis is favorable. Although follow up is too short to assess durability, it is hoped that the unique design and improved valve preservation technique of this device will enhance long-term durability.

Adult↗
PubMed2004

Convergence angle, occlusal reduction, and finish line depth of full-crown preparations made by dental students.

OBJECTIVE: To measure the convergence angle, incisal/occlusal clearance, and finish line depth, which indicate the amount of axial reduction of full metal-ceramic crown preparations made by final-year dental students. METHOD AND MATERIALS: A total of 157 preparations were assessed. Convergence angle and finish line depths were measured by Tool Maker Microscope, while crown height was measured using a digital caliber. RESULTS: The mean convergence angle, faciolingually and mesiodistally, was 22.4 and 25.3 degrees, respectively. The mean for molars was statistically significantly greater than that for other teeth. The incisal/occlusal reduction ranged from 1.8 to 2.2 mm and averaged 2 mm. Buccal shoulder finish line depth averaged 0.86 mm, and mean chamfer finish line depth was 0.74 mm lingually, 0.7 mm mesially, and 0.66 mm distally. The buccal shoulder for mandibular anterior teeth was significantly smaller than for other teeth and averaged only 0.45 mm. CONCLUSION: The mean convergence angle was clinically acceptable. However, shoulder depth was less than the recommended depth of 1.0 to 1.5 mm for metal ceramic crowns. Incisal/occlusal reduction was clinically adequate to provide enough structural durability and color matching.

Analysis of Variance↗
PubMed1995

Insonation and impedance analysis in graft surveillance.

Seventy consecutive patients with infrainguinal bypass grafts entered a 1-year graft surveillance programme involving colour duplex scanning, direct graft insonation and computer-assisted impedance analysis. Graft patients with a positive duplex scan, high frequencies on graft insonation or an impedance value above 0.50 subsequently underwent arteriography. Sixteen patients were excluded before the initial surveillance visit. The 54 remaining patients with grafts (30 vein, 24 synthetic) underwent a total of 137 surveillance visits, with 21 grafts confirmed to be 'at risk'. The sensitivity of an impedance value above 0.55 in identifying these grafts was 86 per cent, rising to 95 per cent when combined with graft insonation. Duplex scanning did not identify any abnormalities in 11 grafts that were either shown by arteriography to be 'at risk' or occluded before arteriography. Impedance measurement and graft insonation are simple screening techniques with a high sensitivity (when combined), which identify 'at risk' infrainguinal grafts. Positive graft insonation or an impedance value over 0.55 will identify all 'at risk' vein grafts while minimizing the number of unnecessary arteriograms.

Angiography↗
PubMed1995

Treatment times for three different types of veneer restorations.

In a longitudinal clinical trial the treatment times needed for the fabrication of veneer restorations (VRs) were recorded and analysed. Treatment times were determined for: (1) direct resin composite (DC), (2) indirect resin composite (IC) and (3) porcelain (P) veneer restorations and for two preparation designs, with and without incisal coverage. Significant effects on the treatment times were found for the factors: (1) type of VR, (2) operator, (3) number of VRs and (4) 'problems' in try-in phase for indirect VRs (IC- and P-VRs). The mean total time needed to perform one DC-VR was 46 min with a 95% confidence interval (c.i.) of 40-54 min, for one IC-VR 70 min (c.i. 60-82 min) and for one P-VR 62 min (c.i. 53-71 min). In the cases where more than one VRs were placed in one patient the times per VR were respectively: DC, 38 min (c.i. 34-44 min); IC, 59 min (c.i. 52-67 min); P, 49 min (c.i. 44-55 min). The results of this study are considered to be useful in further cost-benefit analyses.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2005

Substance distribution in a cochlea model using different pump rates for cochlear implant drug delivery electrode prototypes.

Several studies using animals have shown the protective effects of neurotrophic factors (NF) on spiral ganglion cells (SGC). This is of particular importance since the number of SGCs is considered to be among the factors defining the efficacy of cochlear implants. A device for local inner ear treatment is therefore of great interest. As described previously, we modified a Contour(TM) cochlear implant electrode, to examine the inbuilt canal to be used for fluid release [Paasche, G., Gibson, P., Averbeck, T., Becker, H., Lenarz, T., Stöver, T., 2003. Technical report: modification of a cochlear implant electrode for drug delivery to the inner ear. Otol. Neurotol. 24, 222-227]. In the present study, three different electrode prototypes with openings of the delivery channel at various locations along the electrode array were examined to determine distribution of dye in a cochlea model over time. We compared dye delivery with: (a) release of the dye at the tip, (b) release of the dye at the tip and the side of the electrode, and (c) release of the dye only at the side of the electrode (6 mm from the tip). A mechanical pump was used to drive the system at pump rates of 100, 10, and 1 microl/h. Dye concentration changes along the length of the whole cochlea were investigated. Mean values for all experimental conditions show that the distribution along the array is fastest with two outlets whereas the distribution via a single outlet at the side of the electrode array is not considered to be sufficient. The established experimental setup provides the possibility of investigating prototypes of a fluid based drug delivery system for the treatment of inner ear pathologies in combination with electrical stimulation.

Animals↗
PubMed2004

Effect of blue staining of expandable hydrophilic intraocular lenses on contrast sensitivity and glare vision.

PURPOSE: To evaluate the effect of trypan blue staining of expandable hydrophilic acrylic intraocular lenses (IOLs) on contrast sensitivity and glare. SETTING: Department of Ophthalmology, Federal University, and Oculistas Associados, Rio de Janeiro, Brazil. METHODS: Phacoemulsification with expandable hydrophilic IOL implantation was performed in 19 eyes. Group 1 (stained group) consisted of 12 eyes with the IOL unintentionally stained by trypan blue 0.1% solution during surgery; Group 2 (unstained group) consisted of 7 eyes with IOLs that were not stained because trypan blue was not used during surgery. The eyes were examined postoperatively for Snellen best corrected visual acuity (BCVA), contrast sensitivity BCVA, and glare vision. The examiners were masked to whether the IOL was stained by trypan blue. Inclusion criteria included a BCVA of 20/30 or better 1 month postoperatively. Patients who had other ocular pathology or previous ocular surgery were excluded from the study. RESULTS: The mean postoperative BCVA was 20/24 in the stained group and 20/23 in the unstained group (P =.73). The mean contrast sensitivity visual acuity was 20/31 in the stained group and 20/26 in unstained group (P =.10). The mean glare visual acuity was 20/75 and 20/33, respectively (P =.03). CONCLUSIONS: Patients with expandable hydrophilic acrylic IOLs stained with trypan blue performed significantly worse on a glare vision test than patients whose IOLs were not stained. Cataract surgeons should avoid using trypan blue with this IOL type.

Acrylic Resins↗
PubMed2000

Clinical assessment of high-strength all-ceramic crowns.

STATEMENT OF PROBLEM: All-ceramic crowns are being used extensively. Little data are available on their clinical performance. PURPOSE: This study evaluated the clinical performance of In-Ceram (Vita Zahnfabrik) crowns. MATERIAL AND METHODS: Forty-one patients (16 men, 25 women; mean age 47.3 years, range 18 to 77 years) were examined with a total of 80 In-Ceram all-ceramic crowns fabricated at the University of Iowa College of Dentistry from 1994 to 1997. The percentage distribution for crowns included: 67% anterior single crowns, 26% posterior single crowns, 6% anterior implant crowns, and 1% posterior implant crowns. This study documented the integrity of the junction between crown and tooth, color match to adjacent teeth, secondary dental caries, wear of crown and opposing dentition, and visible cracks in the crown. Alpha, Bravo, and Charlie ratings were assigned with a modified USPHS criteria. The patients were also surveyed with respect to oral hygiene and satisfaction of treatment. Estimations of 4-year success rates and corresponding confidence intervals were calculated by fitting a constant hazard function model with the SAS procedure GENMOD. RESULTS: Marginal integrity for 88% of artificial crowns was rated Alpha or Bravo. Shade match for 99% was Bravo or better. Only 1% of the crowns were carious, and 1 crown exhibited occlusal wear. One premolar crown had a small fracture of veneering porcelain. One molar crown was remade after core fracture. All patients (100%) expressed satisfaction with their crowns. The estimated 4-year success rates (Alpha or Bravo), with 95% confidence intervals in parentheses were calculated as: 83.5% (65.7%-94.6%) for marginal integrity, 95.8% (82.9%-99.8%) for shade match, and 95.5% (81.6%-99.7%) for secondary caries, 100% (88%-100%) for wear, and 100% (88%-100%) for cracks.

Adolescent↗
PubMed2002

Permanent blue discoloration of a hydrogel intraocular lens by intraoperative trypan blue.

A 79-year-old white man had cataract surgery in the right eye with implantation of an Acqua intraocular lens (IOL) (Mediphacos). Trypan blue 0.1% was used during surgery to stain the anterior capsule and enhance the contrast during capsulorhexis. Seven days after surgery, the patient presented with "dark and double" vision (monocular diplopia). The IOL was decentered superiorly and appeared dark blue. The lens was explanted 2 months after surgery and sent for gross and microscopic analyses in a dry state and after hydration. The same analyses were performed on 2 unused lenses of the same design that had been immersed in diluted trypan blue solutions (0.01% and 0.001%). On the explanted lens, the dark blue staining was denser in the optic, especially in its periphery. The blue discoloration could not be removed after 24 hours of lens immersion in a balanced salt solution at 37 degrees C. Permanent staining of the unused lenses was also obtained after immersion in the trypan blue solutions.

Aged↗
PubMed2006

[Ruptured aortoiliac aneurysm with AV-fistula].

HISTORY AND ADMISSION FINDINGS: A 65-year-old man presented an acute swelling of the left leg as the main sign. A pulsatile bruit could be auscultated over the abdomen. INVESTIGATIONS: Doppler ultrasound suggested an aortic aneurysm with fistula. Dynamic bolus-triggered computed tomography demonstrated an aortoiliac aneurysm with a fistula into the confluence of the common iliac veins. TREATMENT AND COURSE: An aorto-iliac graft was inserted surgically and and the patient recovered well. CONCLUSION: In patients with an acute swelling of a lower limb an aorto-iliac aneurysm, though a rare cause, should be considered.

Aged↗
PubMed1994

[Effect of diffractive multi-focal lenses on contrast vision, glare sensitivity and color vision].

BACKGROUND: Due to theoretical considerations an increase in the depth of field of the diffractive IOL may be combined with a reduction in contrast sensitivity, glare sensitivity and colour perception. PATIENTS AND METHODS: A comparative analysis of both eyes was performed in ten patients with a diffractive multifocal IOL (3M 815LE) in one eye and a monofocal IOL in the other eye. Contrast sensitivity was examined by computer generated sine wave gratings of 6 different spatial frequencies; visual acuity with glare and glare sensitivity were determined under 7 different levels of field luminance; colour vision was examined using the Farnsworth-Munsell-100-Hue-test. RESULTS: Contrast sensitivity of the diffractive lens was reduced for intermediate spatial frequencies, but not for low and high frequencies. Visual acuity with glare was only reduced at maximum field luminance; no differences were found in glare sensitivity and colour perception between monofocal and multifocal. CONCLUSION: Altogether, the diffractive lens did not show a dramatic reduction in the examined visual functions compared with the monofocal IOL.

Aged↗
PubMed2004

Transvenous embolization and stent placement for an internal iliac arteriovenous fistula with central iliac vein occlusion.

The authors present a case of traumatic arteriovenous fistula of the internal iliac vessels treated with attempted surgical ligation of the common iliac artery and external iliac artery. The fistula persisted after the operation, and because the patient received no further treatment for the following 6 years, a venous outflow occlusion also developed as a result of high-flow angiopathy. Because the arterial route was eliminated at previous surgery, the fistula and venous occlusion were percutaneously treated via a transvenous approach.

Adult↗