Biomedical subjects
Publications and source records attributed to V Klauss.
We report a case of successful percutaneous transluminal coronary angioplasty guided from pressure-wire measurements in a transplanted patient. Fractional flow reserve, a lesion-specific, pressure-independent index of functional stenosis severity, was used to guide the intervention.
BACKGROUND: The study shows differences between contact lens wearers and patients without history of contact lenses regarding the spectrum of etiological agents in bacterial keratitis. Based on microbiological analysis, there are given recommendations for an optimal initial antibiotic treatment in both groups. MATERIAL AND METHODS: From 1989 to 1997 smears, scrapings and corneal biopsies were taken from 218 patients with bacterial keratitis. The causing pathogens were isolated on directly inoculated culture media and identified by staining and microscopy. The resistance pattern of a total of 275 germs was analysed for different antibiotics. RESULTS: The most frequently isolated germs were Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus spp., Propionibacterium acnes and Pseudomonas aeruginosa. Whereas sensitive gram-positive germs were predominating in contact lens wearers as well as in non-contact lens wearers, multiresistant gram-negative germs could nearly exclusively be isolated from contact lens wearers. Frequently administered antibiotics like aminoglycosides and quinolones are effective in infections caused by Staphylococcus spp., but increasing resistance could be seen to Streptococcus spp. In this case, erythromycin is very sensitive. Gram-negative germs like Pseudomonas aeruginosa are sensitive to quinolones and some aminoglycosides (e.g. tobramycin). CONCLUSION: In contact lens wearers, more aggressive germs have to be considered than in non-contact lens wearers. In such cases, frequently administered antibiotics like amino-glycosides are not effective. To cover problematic gram-negative germs we recommend the application of quinolones alternating with erythromycin. The latter one is more effective than quinolones and aminoglycosides in case of Streptococcus spp. co-involvement.
PURPOSE: To report that silicone oil may be safely removed from immuno-recovered patients with acquired immunodeficiency syndrome (AIDS) after instillation for cytomegalovirus (CMV)-related rhegmatogenous retinal detachment. METHOD: We report two patients with CMV-related retinal detachment who had previously been treated with vitrectomy and silicone oil. RESULTS: Six months after removal of silicone oil, the retina remained attached in both patients. Without specific anti-CMV therapy, there was no relapse of CMV retinitis while patients were undergoing highly active antiretroviral therapy. Best-corrected visual acuity improved in both patients. CONCLUSION: It appears to be possible to remove silicone oil safely from patients with AIDS who show immune recovery, thus avoiding side effects of long-standing silicone oil and increasing quality of life. After silicone oil removal, visual acuity was improved.
UNLABELLED: Few data on the incidence of blindness in Germany are available. We analysed causes of legal blindness for the region Württemberg-Hohenzollern (population 5.5 million) in order to help fill in this gap. MATERIAL AND METHODS: Population-based investigation on the incidence of legal blindness (visual acuity <1/50) based on materials from the social services. Age-dependent blindness incidences were modelled via logistic regression models. RESULTS: 647 blind persons were newly registered in 1994 (blindness incidence 11.6/100,000). The blindness incidence is moderate in infants (4.5/100,000) and decreases further during childhood. At the age of 20 years, the incidence again rises to the former level and remains relatively constant. After the age of 60 years, the incidence increases sharply: 5-year odds ratios are 1.76 (CI: 1.68-1. 85) in women and 1.72 (CI: 1.60-1.84) in men. The blindness incidence is higher in women, 15.6/100,000, compared to 12.2/100,000 in men. The major causes of blindness are: macular degeneration, 3. 92/100,000; diabetic retinopathy, 2.01/100,000; glaucoma, 1.6/100, 000; high myopia, 0.77/100,000; optic atrophy, 0.68/100,000; central nervous system-triggered blindness; 0.56/100,000, and tapetoretinal degenerations, 0.52/100,000. DISCUSSION: Due to monetary incentives for the blind persons, social service files offer accurate and complete data. Besides macular degeneration, glaucoma and diabetic retinopathy are major causes of blindness. Thus, this study suggests further blindness prevention activities for diabetic retinopathy and glaucoma.
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We report a case of successful treatment of coronary artery perforation and cardiac tamponade, which developed during percutaneous transluminal coronary angioplasty, with a PTFE-coated stent. Intravascular ultrasound was first used to overcome the shortcomings of conventional angiography and overlapping of a conventional stent was not as effective as coated-stent placement in sealing a further leakage. Thus, PTFE-coated stents may be an effective alternative to emergency surgery or autologous venous covered stenting and should be considered when coronary artery perforation occurs.
BACKGROUND: Endophthalmitis associated with penetrating injury represents a distinct kind of intraocular infection. The preceding trauma, infective agents and inflammatory changes determine the functional outcome. MATERIALS AND METHODS: In a retrospective study, 18 patients with endophthalmitis were investigated and compared to a control group of 54 patients with penetrating ocular trauma. A number of clinical variables were evaluated for association with an increased risk of endophthalmitis. RESULTS: Risk factors found to be significant were: (1) a purely corneal wound, (2) surgical primary repair more than 24 h after injury and (3) initiation of intravenous antibiotic therapy later than 24 h after trauma. A two-fold increased relative risk was related to the presence of an intraocular foreign body, lens injury and a wound length less than 5 mm. Direct inoculation of surgical specimens and immediate microbiological processing succeeded in the presumptive identification of infective agents with preliminary therapeutic recommendations in 72% of the patients. CONCLUSIONS: In "risk eyes" particular attention should be paid to prophylaxis and signs of infection.
BACKGROUND: Last year's pilot study, which examined for the first time a representative group of patients with Chagas disease, showed that in this parasitosis changes in the ocular fundus can be expected in the form of defects of the retinal pigment epithelium. Examination of more patients in this study should give further information about the character and extent of the alterations found. MATERIALS AND METHODS: After serological confirmation of the disease, we performed an ophthalmological examination of the anterior and posterior segments. RESULTS: In 21 out of 23 patients the fundus was unobtrusive; 1 patient showed fibrae medullares and 1 patient clear pigment dispersion on the posterior pole. Together with the pilot study, a total of 102 chagasic patients were examined. In 8 patients (7.8%) defects of the retinal pigment epithelium were found, which did not cause any significant loss of vision. CONCLUSIONS: We presume that the described defects are a matter of rare and harmless postinflammatory or immunological changes in the American type of trypanosomiasis.
BACKGROUND: Propionibacterium acnes has been described as a causative agent of postoperative endophthalmitis. This gram-positive, immotile, non-spore-forming bacterium is highly pleomorphic and grows under conditions of low to no oxygen concentration. It is commonly found on the skin at the openings of sebaceous glands and on hairs. A near-symptomless postoperative endophthalmitis occurs particularly when Propionibacteria are enclosed in the capsular bag. We investigated to what extent the number of P. acnes in the conjunctival sac can be reduced by preoperative disinfection with polyvidone iodine (1%). PATIENTS AND METHODS: A total of 261 patients with intrabulbar surgery had two conjuctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after disinfection with polyvidone iodine before opening the conjunctiva. RESULTS: Of the 261 swabs, 60 (23%) taken prior to polyvidone iodine application were positive for Propinibacterium acnes. Following polyvidone iodine treatment, a further 5 (1.9%) remained culture-positive. After disinfection, 55 (92%) of the 60 positive swabs for Propionibacterium acnes remained culture-negative. CONCLUSIONS: We concluded that a significant reduction of P. acnes can be achieved by preoperative application of polyvidone iodine (1%) (P < 0.001).
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Explore the source record for details and available documents.
BACKGROUND: To compare the efficacy and safety of tacrolimus and cyclosporine in heart transplantation, this single-center, prospective, randomized, open-label clinical trial was undertaken. METHODS: Seventy-three adult patients were randomly assigned at the time of transplantation to receive either tacrolimus (n=43) or cyclosporine (n=30) as the primary immunosuppressant. Ten of the 43 patients in the tacrolimus group received the drug intravenously in the perioperative period; all other patients received only oral tacrolimus. RESULTS: With a mean follow-up of 27 months, patient survival rates (tacrolimus 83%, cyclosporine 81%) were similar. Fewer patients experienced acute rejection in the tacrolimus group (79%) than in the cyclosporine group (100%), but the difference was not statistically significant. The number of infections and dialysis and insulin requirements were similar for the 2 treatment groups, but the proportion of patients requiring multidrug antihypertensive regimens was lower in the tacrolimus group (12.5% vs 50.0% at month 6; p=.025). The interpatient variance in pharmacokinetic parameters in a subset of 10 patients was much higher after the first oral dose of tacrolimus than at steady-state (eg, first-dose time at which maximal concentration is reached (t(max)): 3.5+/-2.5h, steady-state t(max): 2.0+/-0.7h), and patients treated with intravenous tacrolimus (n=13) rather than oral tacrolimus (n=30) reached target concentrations faster and with less interpatient variability (eg, at day 0: 9.72+/-10.9 ng/mL intravenously vs 3.31+/-8.1 orally). CONCLUSIONS: Tacrolimus was associated with similar efficacy and safety profiles compared with cyclosporine. The higher interpatient variance in absorption associated with oral tacrolimus during the first few days after transplantation would suggest that intravenous tacrolimus should be used during the perioperative period.
BACKGROUND: Transplant coronary artery disease is the major factor limiting long-term survival after cardiac transplantation. Both intravascular ultrasound imaging (IVUS) and intracoronary flow studies have been used to assess the morphologic and functional importance of the disease. However, the impact of epicardial intimal thickening, as quantitated by IVUS, on the resistance vessel response to adenosine has not been explored. METHODS AND RESULTS: Seventy-six coronary arteries without angiographically overt coronary disease (diameter stenosis visually, < or =50%) were studied with both IVUS and intracoronary Doppler in 54 patients 0.5 to 127 months after transplantation. Mean intimal index and mean lumen cross-sectional area (CSA) were determined by IVUS, and the average was obtained for every coronary artery. Coronary flow average peak velocity (APV) was obtained by Doppler before and after administration of 16 microg adenosine to calculate coronary flow velocity reserve (CFVR) and coronary vascular resistance index (CVRI). The hyperemic pressure-flow velocity ratio (hyperemic mean aortic pressure/hyperemic APV) as an index of minimal coronary resistance was further derived. The intimal index (mean, 20.0+/-10%) did not correlate with either CFVR (mean, 2.9+/-0.7, r=.12) or CVRI (mean, 0.33+/-0.1, r=.16). However, a significant correlation between the intimal index and the hyperemic pressure-flow velocity ratio (mean, 1.52+/-0.47 mm Hg/cm/s, r=.74, P<.0001) was found. The hyperemic pressure-flow velocity ratio was not influenced by the presence or absence of left ventricular hypertrophy or a mild acute rejection period (International Society for Heart and Lung Transplantation grades IA and IB). CONCLUSIONS: This study shows that in patients without angiographically overt coronary disease, the degree of epicardial intimal thickening as quantified by IVUS did not predict the adenosine vasodilator response, when determined by commonly used parameters such as CFVR and CVRI. The hyperemic pressure-flow velocity ratio best reflected the functional significance of transplant coronary artery disease.
PROBLEM AND OBJECTIVE: Cardiac allograft vasculopathy influences long-term survival of patients after heart transplantation. Donor-transmitted coronary artery disease may contribute to the further development of cardiac allograft vasculopathy. The aim of this study was to characterize by intracoronary ultrasound the extent and frequency of transmitted coronary artery disease. PATIENTS AND METHODS: Intravascular ultrasound studies were performed at routine angiography in 33 patients (26 men, 7 women, mean age 51 [23-69] years) early after heart transplantation. Plaque morphology was analysed in 153 coronary segments of 52 epicardial coronary arteries. RESULTS: Relevant atherosclerosis (defined as maximal plaque thickness > or = 0.5 mm in at least one coronary segment) was found in 17 patients (52%), while angiography showed irregularities in only 7 patients (21%). Maximal plaque thickness in patients with relevant atherosclerosis was 1.13 +/- 0.32 mm, mean plaque index was 19.2 +/- 10.2%. Plaque formation was eccentric, and plaques were predominantly located in proximal segments. Morphologic changes affecting more than one segment were found in 52% of the patients. Comparing clinical factors, only donor age predicted the degree of atherosclerosis. CONCLUSIONS: In more than one half of the patients studied early after heart transplantation, Intravascular ultrasound revealed epicardial atherosclerotic lesions which were incompletely identified by coronary angiography. The degree of atherosclerosis was closely related to donor age. The potential influence of donor transmitted coronary artery disease on the progression of transplant coronary artery disease requires further longitudinal studies.
BACKGROUND: The effects of ultrasound-guided high-pressure stenting on late stent and reference segment dimensions are unknown. In this study, we report about angiographic and ultrasound measurements to assess the amount and distribution of neointimal ingrowth within the stent and the changes of plaque burden and dimensions within the reference segments. METHODS AND RESULTS: Sixty-eight consecutive patients with 72 lesions received single or multiple Palmaz-Schatz coronary stents with a standardized protocol for stent optimization under ultrasound guidance. The residual angiographic diameter stenosis was 3 +/- 12% (reference diameter, 3.16 +/- 0.61 mm). At follow-up 4.8 +/- 2.5 months later, angiography revealed a diameter stenosis of 27 +/- 21% with a restenosis rate of 15.3% (confidence interval: 7.8% to 25.6%). Lumen renarrowing within the stent was exclusively due to neointimal ingrowth; no stent compression was observed. The neointima covered 20 +/- 20% of the stent area and was more pronounced in the midportion of the stent. Volumetric assessment performed in 26 patients resulted in 13 +/- 14% or 65 +/- 28% of the stent volume occupied by neointimal ingrowth in patients without or with restenosis, respectively. Vessel remodeling had an impact on lumen dimensions only at reference sites but not within the stent. Plaque burden of 46 +/- 11% and 48 +/- 11% at the proximal and distal reference sites, respectively, did not show a relevant progression during the follow-up. CONCLUSIONS: Serial ultrasound analyses did not show any evidence of stent compression or relevant vessel remodeling. Restenosis was solely due to neointimal ingrowth. Despite a considerable plaque burden within the reference segments, there was no relevant progression of the disease adjacent to the stent.
This case report describes the intravascular ultrasound (IVUS) evaluation of a coronary artery aneurysm, developed in a stented segment within 6 mo after bailout stenting. Analysis of the IVUS images provides in vivo insights in the vessel-remodeling process after mechanical injury. The proximal entrance of the false lumen could be clearly visualized as well as the relationship between the stent struts, neolumen, and vessel wall. The discussion is focused on the options for management of such patients.
BACKGROUND: After stent deployment, larger balloons are frequently needed to optimize stent expansion according to angiographic and intravascular ultrasound (IVUS) criteria. The objective of this trial was to assess the feasibility and safety of a single-balloon approach for predilation, stent implantation, and optimization with a differential-compliant balloon allowing for focal overexpansion. We also evaluated the achieved degree of stent expansion according to IVUS criteria. METHODS AND RESULTS: Forty-seven consecutive patients with 50 lesions received single or multiple Palmaz-Schatz coronary stents. The final angiographic diameter stenosis was -2.6 +/- 12.6% (reference diameter, 2.89 +/- 0.44 mm), and the residual lumen area stenosis (IVUS) was 13.0 +/- 12.3% (reference area 10.8 +/- 3.0 mm2). This result was achieved in two steps (first angiographic, then IVUS-guided stent optimization). The balloon inflation pressure increased from 13.1 +/- 3.0 bar at step 1 to 16.1 +/- 3.0 bar at step 2, which resulted in a balloon to artery ratio of 0.97 +/- 0.12 and 1.10 +/- 0.15, respectively, at the low-compliant peripheral balloon segments. The more compliant central balloon segments showed a balloon to artery ratio of 1.09 +/- 0.17 and 1.28 +/- 0.17, respectively. The primary success rate for stent deployment was 94%. Acute complications included two type A and one type B dissection without clinical sequelae. CONCLUSIONS: The single-balloon approach for stenting is feasible and safe. The acute result is comparable to that of other studies with IVUS-guided stent optimization, the primary success rate, however, is slightly lower with the presently available catheter.