PubMed Health⌕ Search

Biomedical subjects

J Ge

Publications and source records attributed to J Ge.

At least 91 records · Page 5Linked to original sources
PubMed1999

The study of influencing factors on the growth characters of Sprague-Dawley rat retinal neurons in vitro.

PURPOSE: To investigate the influencing factors in culturing Sprague-Dawley (S-D) rats retinal neurons in order to lay foundation for further experimental research. MATERIALS AND METHODS: Retinal cells were plated on plastic plates and coverslips coated with poly-l-lysine or ethylene imine polymer for primary culture. The cultured cells were divided into following groups: 1. Culture medium changed every 2 to 3 days vs changed only once; 2. Cytosine arabinoside (Ara-C) added to the culture medium vs not added. The cells were observed and pictured under inverted phase contrast microscope. The cells were identified through immunocytochemistry. RESULTS: The immunofluorescence showed that most of the cultured cells were neurons, among them were a few retinal ganglion cells. In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c, the neurons intended to aggregate into clusters with relatively straight neurites. In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c, the neurons grew dispersively with bent neurites. Both of them survived for 2 to 3 weeks. The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks. In the group of which medium changed several times, the survival time of neurons was shorter than that in the medium changed only once. CONCLUSIONS: The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth. It is not favorable for the growth of the neurons by changing culture medium many times. Ara-c may possibly have side effect on the growth of retinal neurons.

Animals↗
PubMed1999

Corrective change of retinal thickness measured by optical coherence tomography and histologic studies.

PURPOSE: To evaluate the correlation of retinal thickness between optical coherence tomography (OCT) images and histologic slides. METHODS: Retinal thickness was measured in 16 rabbit retinal histologic slides. The same eyes had been previously measured by OCT for the comparison of results between two methods. Retinal thickness of each OCT image section was measured using both the manually assisted (requiring localization of reflectivity peaks by observer) and automated modes of the computer software. RESULTS: Retinal thickness measured by OCT demonstrated a high degree of correlation with retinal histologic study. The automated method (Cc = 0.66, P < 0.01) was less reliable than the manually assisted one (Cc = 0.84, P < 0.001). The former had an error in 95% confidence interval, ranged between -0.71 and 11.09 microns. The latter had a less error, ranged from -2.99 to 5.13 microns. CONCLUSION: OCT can quantitatively measure the retinal thickness. However, automatical identification of the reflective boundaries by computer may result in errors in some cases. To measure the retinal thickness by manually assisted mode can increase the accuracy.

Animals↗
PubMed1999

New management of malignant glaucoma by phacoemulsification with posterior chamber foldable intraocular lens implantation.

OBJECTIVE: To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma. PATIENTS AND METHODS: Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study. 12 patients developed malignant glaucoma after filtration surgery. 1 developed after peripheral iridectomy. 1 patient developed malignant glaucoma without any clear cause. Cataract phacoemulsification was performed. Posterior chamber intraocular foldable lens was implanted in 10 cases of patients. RESULTS: All 14 patients were cured with normal intraocular pressure, normal anterior chamber depth and increased visual acuity. CONCLUSION: Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

Aged↗
PubMed1999

[Effect of N-methyl-D-aspartate and dexamethasone on apoptosis of rat cultured retinal ganglion cells].

PURPOSE: To investigate the effect of N-methyl-D-aspartate(NMDA) and Dexamethasone on cultured rat retinal ganglion cells (RGCS). METHODS: RGCs were obtained from 1-3 days old SD rats. In two groups, exposure of cocultured ganglion cells to N-methyl-D-aspartate (20-500 mumol/L) lasted for 24 hours. Apoptotic cells were identified by Hochest 33258 in one group; In another group, 0.4% Trypan blue dye was added. Cells excluding the dye were counted, and the survival rate of cells was determined by the ratio of the excluding cells in the experiment over in the control; Cocultured RGCs and purified RGCs were exposed to Dexamethasone(1 x 10(-4), 1 x 10(-5) and 1 x 10(-6) mol/L). After 24 hours, apoptotic cells were identified by Hochest33258. RESULT: Cocultured RGCs showed distinct morphological appearance of apoptotic cells when they were exposed to NMDA. The survival rate of cells was dose-related to the concentration of NMDA. Cocultured RGCs didn't show typical apoptotic appearance at 24 hours after exposure to Dexamethasone. But purified RGCs did so, even in the control group. CONCLUSION: NMDA has the effect of inducing cocultured RGCs apoptosis. Dexamethasone had no this effect on RGCs. Without additional neurotrophic factors, purified RGCs may become apoptotic cells when cultured in vitro for 24 hours.

Animals↗
PubMed1998

Pharmacokinetics and pharmacodynamics of oral methotrexate and mercaptopurine in children with lower risk acute lymphoblastic leukemia: a joint children's cancer group and pediatric oncology branch study.

We prospectively assessed the pharmacokinetics of methotrexate, mercaptopurine, and erythrocyte thioguanine nucleotide levels in a homogenous population of children with lower risk acute lymphoblastic leukemia and correlated pharmacokinetic parameters with disease outcome. The maintenance therapy regimen included daily oral mercaptopurine (75 mg/m2) and weekly oral methotrexate (20 mg/m2). One hundred ninety-one methotrexate doses and 190 mercaptopurine doses were monitored in 89 patients. Plasma drug concentrations of both agents were highly variable. The area under the plasma concentration-time curve (AUC) of methotrexate ranged from 0.63 to 12 micromol*h/L, and the AUC of mercaptopurine ranged from 0.11 to 8 micromol*h/L. Drug dose, patient age, and duration of therapy did not account for the variability. Methotrexate AUC was significantly higher in girls than boys (P =.007). There was considerable intrapatient variability for both agents. Erythrocyte thioguanine nucleotide levels were also highly variable (range, 0 to 10 pmol/g Hgb) and did not correlate with mercaptopurine dose or AUC. A Cox regression analysis showed that mercaptopurine AUC was a marginally significant (P =.043) predictor of outcome, but a direct comparison of mercaptopurine AUC in the remission and relapsed patient groups failed to show a significant difference. Methotrexate and mercaptopurine plasma concentrations and erythrocyte thioguanine nucleotide levels were highly variable, but measurement of these pharmacokinetic parameters at the start of maintenance will not distinguish patients who are more likely to relapse.

Administration, Oral↗
PubMed1998

Improved assessment of coronary stenosis severity using the relative flow velocity reserve.

BACKGROUND: Myocardial fractional flow reserve (FFR) is based on pressure measurements. We have now sought to establish a Doppler-based concept of relative flow velocity reserve (RFVR) for the functional assessment of stenosis severity in epicardial coronary arteries. A clear threshold value to discriminate the functional severity of a coronary stenosis does not exist for coronary flow velocity reserve (CVR) based on intracoronary Doppler measurements. In contrast, the concept of FFR, which is based on intracoronary pressure measurements, has been extensively validated. An FFR value below 0.75 reliably indicates a significant stenosis. METHODS AND RESULTS: RFVR is calculated as the ratio between distal CVR in the stenosed target vessel and distal CVR in a nonstenotic reference vessel. In 21 patients, RFVR was determined in 24 target vessels by use of intracoronary adenosine and correlated to the FFR, determined as the ratio of mean poststenotic to aortic pressures, in the target vessel. Stenosis severity was classified according to quantitative coronary angiography analysis. Reference diameter was 3.0+/-0.4 mm (mean+/-SD), and area stenosis was 74+/-15% (range, 40% to 95%). CVRs in the target and reference vessels were 2.1+/-0.5 and 2.6+/-0.7, respectively. FFR ranged from 0.49 to 0.99 (mean, 0.81+/-0.15) and RFVR from 0.53 to 1.0 (mean, 0.82+/-0.13). Poststenotic CVR did not correlate with either percent area stenosis (r=0.27, P=NS) or FFR (r=0.33, P=NS). In contrast, FFR as well as RFVR showed a curvilinear relation to percent area stenosis (r=0.89, P<0.0001 and r=0.79, P<0.0001, respectively). There was a close linear correlation between FFR and RFVR (r=0.91, P<0.0001). CONCLUSIONS: RFVR correlates closely to FFR and to percent area stenosis, whereas the correlation of CVR with FFR and percent area stenosis is rather poor. RFVR is a promising new concept for assessment of coronary stenosis severity and clinical decision making based on Doppler measurements.

Aged↗
PubMed1998

Central 5-HT3 receptors in P and in AA alcohol-preferring rats: An autoradiographic study.

Considerable evidence exists for an involvement of serotonergic mechanisms in the control of alcohol consumption. In the present study, an extensive 5-hydroxytryptamine (5-HT3) receptor autoradiographical investigation was performed using two genetically selected rat strains, alcohol preferring (P) and Alko alcohol (AA) alcohol-preferring rats, as well as the corresponding alcohol nonpreferring (NP) and Alko nonalcohol (ANA) alcohol-nonpreferring rats. The aim was to determine if there are any differences in 5-HT3 binding levels that may illuminate mechanisms of alcohol preference in these animals. For quantitating 5-HT3 binding sites, [3H]S(-)zacopride (0.5 nM) was used. Non-specific binding was measured in the presence of granisetron 10(-6) M. The [3H]S(-)zacopride binding density was measured in two subregions of the amygdaloid nucleus, frontal cortex, piriform cortex, cingulate laminae, parietal anterior cortex, parietal medial cortex, hippocampus CA1, hippocampus CA3, and entorhinal cortex. In all the brain areas investigated, the results showed no differences between AA and ANA rats. In P rats, compared to NP controls, there was a 30% lower 5-HT3 binding level in the lateral nucleus and the posteromedial cortical nucleus of the amygdala. These findings suggest that the expression of high alcohol preference in genetically selected P and AA rats is not associated with a general alteration of central 5-HT3 receptors, although a lower 5-HT3 receptor level in the amygdala of P rats may contribute to the phenotype of this strain of animals.

Alcohol Drinking↗
PubMed1998

Role of intravascular ultrasound in the evaluation of mechanisms of coronary interventions and restenosis.

Intravascular ultrasound (IVUS) has emerged from being a research tool to becoming an intrinsic part of modern invasive cardiology. The main reason is its ability to obtain "in vivo" microanatomy. For the first time it is possible to base decisions not only on lumenograms but also on vessel wall assessment. The intervention-associated potential of IVUS includes the ability to allow optimal device selection, i.e., rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of percutaneous transluminal coronary angioplasty (PTCA) on vessel-wall morphology can be studied in great detail and the effect on luminal gain can be assessed almost on-line. Several groups have showed that the residual plaque area, even after angiographically successful PTCA, still lies in the range of 60%. A significant reduction of this percentage may influence long-term outcome after PTCA. Minimal luminal areas and residual plaque area after PTCA seem to be an indicator of restenosis, whereas the presence or absence of dissections seem to be less predictive. The main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with a significant increase in postprocedural luminal diameters and finally the ability to withhold anticoagulation in patients with optimal stent deployment.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Treatment of coronary pseudoaneurysm by stent-graft implantation].

HISTORY AND CLINICAL FINDINGS: A 54-year-old man was urgently admitted because of sudden onset of progressively worsening angina pectoris, his first attack. Physical examination was unremarkable. INVESTIGATIONS: Electrocardiography and laboratory tests excluded acute myocardial infarction. With the exception of hypercholesterolemia (total cholesterol 247 mg/dl) laboratory tests were normal. Coronary angiography revealed a 60% eccentric narrowing in the proximal part of the interventricular branch with adjacent aneurysmatic dilatation. Intravascular ultrasound (IVUS) showed a coronary pseudoaneurysm, its cavity communicating with the empty atheroma hole of an adjacent ruptured coronary plaque. TREATMENT AND COURSE: A 19 mm stent graft was implanted, via a percutaneously inserted balloon-catheter system, in the region of the stenosis and the pseudoaneurysm. Subsequent angiography demonstrated a smooth nonstenotic lumen. The membrane of the graft (made of polytetrafluoroethylene [PTFE]), fixed between two thin metal stents, had occluded the pseudoaneurysm. Occlusion of an immediately distal septal branch briefly produced an asymptomatic rise of creatine kinase to maximally 173 U/l. Oral medication included ticlopidine hydrochloride (2 x 250 mg daily for 4 weeks). The patient was symptom-free after the procedure and was discharged 5 days later. CONCLUSION: Implantation of a new type of stent-graft provides quick and uncomplicated treatment of a coronary aneurysm. The membrane fixed between two stents prevents wash out of any thrombi. The method may also be applicable to other potentially thrombus-containing lesions.

Blood Vessel Prosthesis Implantation↗
PubMed1998

Preferential blockade of cholecystokinin-8S-induced increases in aspartate and glutamate levels by the CCK(B) receptor antagonist, L-365,260, in rat brain.

In the present studies, the ability of a locally delivered cholecystokinin (CCK) receptor agonist and systemically delivered antagonists to modulate extracellular levels of aspartate and glutamate in the frontal cortex of anaesthetised rats and frontal cortex and caudate-putamen of freely moving rats was investigated using an in vivo microdialysis technique. In the anaesthetised rats, local application of sulphated CCK octapeptide (CCK-8S, 10 microM) into the frontal cortex enhanced extracellular aspartate levels to a maximum of 265+/-16% of the basal levels, whereas glutamate levels were increased to a maximum of 168+/-7% of the basal levels. Given 40 min prior to the cortical perfusion of 10 microM of CCK-8S, the CCK(B) receptor antagonist, L-365,260 (20 mg/kg, s.c.), limited the rise in cortical aspartate by over half to 170+/-10% of the basal levels. However, this same dose of L-365,260 still allowed CCK-8S to increase glutamate by 44+/-15% above the basal levels. Whereas the enhanced glutamate levels were totally unaffected by systemic administration of the CCK(A) receptor antagonist, L-364,718 (20 mg/kg, -40 min, s.c.), this treatment was able to limit the elevation in aspartate to 220+/-4% of the basal levels. In the freely moving rats, local perfusion of CCK-8S (10 microM) increased aspartate and glutamate levels to maxima of 275+/-12% and 225+/-14% of the basal levels, respectively, in the frontal cortex. In the caudate-putamen, aspartate and glutamate levels were also elevated by CCK-8S (10 microM) to 248+/-15% and 185+/-12% of the basal levels, respectively. The respective increase in aspartate and glutamate induced by CCK-8S (10 microM) were limited to 140+/-10% and 124+/-6% (frontal cortex), of the basal levels, and 162+/-15% and 143+/-8% (caudate-putamen), by 40 min pretreatment with L-365,260 (20 mg/kg, s.c.). In conclusion, CCK-8S was able to enhance both aspartate and glutamate overflow in the frontal cortex of anaesthetised rats, and frontal cortex and caudate-putamen of freely moving rats. These increases were preferentially offset by the selective CCK(B) receptor antagonist, L-365,260, since no influence could be discerned using the selective CCK(A) receptor antagonist, L-364,718.

Animals↗
PubMed1998

Comparison of electron-beam computed tomography and intracoronary ultrasound in detecting calcified and noncalcified plaques in patients with acute coronary syndromes and no or minimal to moderate angiographic coronary artery disease.

We compared intracoronary ultrasound (ICUS) and electron-beam computed tomography (EBCT) on a coronary segmental basis in 40 consecutive patients with acute coronary syndromes and no or minimal to moderate angiographic disease (53+/-10 years; 34 men, 6 women). ICUS was used to define plaques, and EBCT was used to quantify coronary calcium (using a threshold of a CT density > 130 Hounsfield units in an area > 1.03 mm2). In a site-by-site analysis, coronary segments were defined as normal if both methods were negative, as containing noncalcified plaques if only ICUS was positive, and as containing calcified plaques if both methods were positive. A total of 222 coronary segments were analyzed (5.6+/-1.9 segments per patient). In 36 patients (90%), a total of 95 segments with plaques were identified, whereas in 4 patients (10%), only normal segments were seen. Of the 95 segments with plaques, 61 (64%) were calcified, and 34 (36%) were noncalcified. There was a linear relationship between the number of segments with calcified and with noncalcified plaques (r = 0.86, p <0.0001), but the mean relative frequency of segments with calcified plaques (55+/-38%) was highly variable. Calcium was found in 15 of 16 patients (93%) with 3 or more segments with plaques, while it was found in only 12 of 20 patients (60%) with one or 2 segments with plaques (p = 0.026). Younger age, higher low-density lipoprotein-cholesterol levels, diabetes, and active smoking predicted a higher relative frequency of segments with noncalcified plaques. Thus, in patients with acute coronary syndromes but no angiographically critical stenoses, there is a linear relationship between segments with calcified plaques versus segments with noncalcified plaques. However, while the mean ratio of these segments is close to 1:1, it is highly variable among individual patients.

Acute Disease↗
PubMed1998

Extramural vessel wall hematoma causing a reduced vessel diameter after coronary stenting: diagnosis by intravascular ultrasound and treatment by stent implantation.

An extramural vessel wall hematoma occurred immediately after implanting a coronary stent in an in-stent-restenosis of the intermedius branch. Angiography showed a significant luminal reduction distal to the intervention site. Intravascular ultrasound revealed an extramural echolucent zone compressing the vessel lumen. Stent implantation compressed the hematoma and allowed adequate myocardial perfusion. This demonstrates the value of intravascular ultrasound (IVUS) in cases of unusual angiographic results which can help to manage complications after coronary intervention.

Coronary Angiography↗
PubMed1998

[Digital archiving of imaged heart catheter studies on CD-R. Detection of irreversible CD damage].

The digital archiving has great advantages compared to the standard 35-mm X-ray cinefilm documentation. The data are immediately available and quantitative coronary angiography possible. In addition the technical progress is enhancing the availability of data. The loss of films is nearly eliminated, as only copies of the digital archive data are delivered. In addition a big advantage concerning pollution is present, when CD Rs are used. We report about the damage of CD Rs after 89, 162, 181 and 252 days when they were stored in polypropylene material containing envelopes. The damaged CD Rs all belonged to the provider Verbatim, whereas CD Rs of the provider Rank Xerox or Kodak were never damaged. In contrary to the Verbatim company, Rank Xerox gave written confirmation for 10-year storage and a written confirmation, that the storage in the polypropylene envelopes is possible. Mechanical, thermal damage and damage by humidity have to be discussed as well as chemical interactions of the CD Rs surface with the polypropylene material. As the digital storage for X-ray images has to be provided for 10 years in Germany, it is concluded, that the storage in polypropylene envelopes has to be avoided, when a written confirmation by the company is not given. These observations should stimulate to better control and analyze the real storage availabilities of digital data and provide in the future other media than CD R for long-term archiving.

CD-ROM↗
PubMed1998

[Intravascular ultrasound--the new gold standard?].

Intravascular ultrasound (IVUS) has evolved to a research tool to an intrinsic part of modern invasive cardiology. The main reason is the capability to obtain "in-vivo" micro anatomy by means of miniaturized echo-transducers with an outer diameter of 2.9-3.5 French. For the first time it is possible to base decisions not only on lumenograms but also on vessel wall assessment. The capabilities of IVUS can be divided in its diagnostic and intervention associated potentials. The diagnostic strength of IVUS is the ability to monitor compensatory coronary artery enlargement as a response to arteriosclerosis, to assess intermediate lesions, to reveal occult left main stem disease, and angiographically "silent" arteriosclerosis. In conjunction with the estimation of intracoronary flow reserve, patients with the diagnosis of coronary "syndrome X" can be better classified into those with or without early signs of arteriosclerosis. Additionally, IVUS is at present the only method allowing the classification of coronary artery lesions according to the AHA/ACC Stary classification. The intervention associated potentials of IVUS are the ability to allow optimal device selection, i.e. rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of PTCA on vessel wall morphology can be studied in great detail and the effect on luminal gain can be assessed almost on-line. The correlation between IVUS and angiography for estimation of luminal dimensions is inferior, because angiography is not able to describe complex luminal geometries. Several groups showed that the residual plaque area even after angiographically successful PTCA lies still in the range of 60%. A significant reduction of this number may influence long-term outcome after PTCA. Minimal luminal areas and residual plaque area after PTCA seem to be an indicator of restenosis, while the presence or absence of dissections seem to be less predictive. Additionally, the main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with significant increase in post-procedural luminal diameters and finally the ability to withhold anticoagulation in patients with optimal stent deployment and to lower subacute stent thrombosis rates. First results for IVUS guided PTCA show a superior gain in post procedural free lumen without an increased complication rate. In the future, integrated devices, like balloons on IVUS catheters, steerable catheters, integrated flow and pressure transducers, tissue characterisation, and 0.018 inch IVUS guidewires will further enhance the usefulness of IVUS.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Management of coronary perforation after percutaneous balloon angioplasty with a new membrane stent].

A 59 year old patient underwent percutaneous transluminal coronary angioplasty of a de novo stenosis of the proximal right coronary artery. Vessel perforation occurred after balloon angioplasty and was successfully treated by implantation of a new stent graft, which completely covered the perforation without residual leakage. Emergency coronary surgery could, thus, be avoided.

Angioplasty, Balloon, Coronary↗
PubMed1998

[New imaging methods for visualizing coronary arteries].

Techniques in the field of coronary artery imaging can be divided into two groups: invasive and non-invasive methods. Apart from the conventional coronary artery angiography, invasive methods include intracoronary ultrasound, intracoronary angioscopy, and optical coherence tomography. Non-invasive methods include magnetic resonance tomography, synchrotron-coronary angiography, and electron beam computed tomography. In the late 1980s, intracoronary ultrasound has come into clinical practice. It offers a real-time, cross-sectional image of the coronary artery in high resolution. Coronary arteries enlarge in the presence of atherosclerotic plaque formation in order to compensate for luminal narrowing caused by plaque formation (remodeling). With coronary angiography, the plaque formation cannot be detected until a lumen reduction of about 40-45%. With intravascular ultrasound, the early stages of atherosclerosis can clearly be demonstrated. In combination with the intracoronary Doppler technique, syndrome X can be differentiated. Another important role of intracoronary ultrasound in the diagnosis of coronary artery disease is to guide coronary interventions and to assess the result of coronary interventions especially to evaluate the result of stent implantation. Due to the clinical use of intracoronary ultrasound and the guidance of high pressure stent implantation, the incidence of acute stent thrombosis has decreased to about 1%. Coronary angioscopy portrays the surface of the vessel lumen. It is helpful to identify the mural thrombus especially to differentiate fresh and chronic thrombus formation. Magnetic resonance tomography is able to image the coronary arterial contour of the proximal segment. With today's gating technique, it is possible to portray the whole coronary tree and avoid disturbances resulting from the heart beat and respiration. Electron beam computed tomography is a very promising technique in screening for coronary artery disease. It is a very sensitive method to identify coronary calcification and, thus, to detect atherosclerotic plaque. Studies have shown that the presence of calcification almost invariably indicates the presence of coronary artery disease and that the absence of calcification can nearly rule out significant coronary artery disease. Moreover, a close correlation exists between the amount of calcification and the severity of coronary artery disease. Additionally, in combination with contrast injection, coronary artery perfusion can be evaluated. This is important to assess the conductance of coronary stent and bypass graft.

Coronary Artery Disease↗
PubMed1998

[Arguments against conventional balloon dilatation of recurrences within the stent].

Today, stent restenosis is the major limitation of coronary stent implantation. Despite several prospective randomized trials, which documented significantly lower restenosis rates after stenting compared to conventional balloon angioplasty for the treatment of de-novo stenoses, restenotic lesions, bypass graft stenoses and symptomatic dissections, in daily clinical practice restenosis rates after coronary stenting are reported between 18% and 78% depending on the lesions treated. Interventional treatment options for symptomatic stent restenosis include repeat balloon angioplasty, a combination of ablative approaches (rotablation, laser angioplasty, directional atherectomy) with balloon angioplasty, and stent-in-stent (sandwich technique) placement. Long-term success for the treatment of focal (< or = 10 mm) stent restenosis seems to be equivalent for all these strategies with a restenosis rate of about 30% while after balloon angioplasty of diffuse (> 10 mm) stent restenosis restenosis rates range between 35% and 85%. From a pathophysiological point of view it seems conclusive that balloon angioplasty can only achieve a limited lumen by plastic deformation of the obstructive neointimal tissue, which is responsible for stent restenosis. In this situation techniques, which ablate the neointimal tissue, can create a more adequate lumen without extensive vessel trauma supported by lower restenosis rates between 25% and 56% compared to balloon angioplasty alone. Prospective randomized trial are needed in the future to support a superiority of ablative techniques over conventional balloon angioplasty for the treatment of stent restenosis.

Angioplasty, Balloon, Coronary↗