Activation of nuclear factor-kappa B significantly contributes to lumen loss in a rabbit iliac artery balloon angioplasty model.

BACKGROUND: To investigate the contribution of inflammation to postangioplasty lumen loss, we used an adenoviral gene therapy approach to inhibit the central inflammatory mediator nuclear factor-kappaB (NF-kappaB) by overexpression of its natural inhibitor, IkappaBalpha. METHODS AND RESULTS: The adenovirus carrying human IkappaBalpha was applied immediately after balloon dilatation by a double-balloon catheter in a rabbit iliac artery restenosis model. Immunohistochemistry of IkappaBalpha revealed that mainly smooth muscle cells of the media but also cells of the adventitia were transduced and expressed the transgene IkappaB alpha for >/= 8 days. At this time point, intercellular adhesion molecule-1 (30%) and monocyte chemotactic protein-1 (50%) expression, as well as recruitment of macrophages into the wounded area (90%), were significantly reduced in IkappaB alpha-treated vessels. In addition, expression of inhibitor of apoptosis proteins was reduced and the percentage of apoptotic cells was increased compared with control-treated contralateral vessels. Animals killed 5 weeks after treatment exhibited a significantly reduced degree of lumen narrowing (P<0.02) on the side treated with adenovirus IkappaBalpha. The lumen gain of approximately 40% was due to positive remodeling. CONCLUSIONS: From these data, we conclude that balloon angioplasty-induced activation of NF-kappaB contributes to lumen loss likely via induction of an inflammatory response and a decrease in the rate of apoptosis. These data show for the first time that inflammation mediated by NF-kappaB is involved in postangioplasty lumen narrowing. Specific and more potent inhibitors of NF-kappaB might therefore be a useful therapeutic measure to improve clinical outcome after balloon dilatation.

Preoperative fast MRI of brain tumors using three-dimensional segmented echo planar imaging compared to three-dimensional gradient echo technique.

The purpose of this study was to compare the diagnostic efficacy of a newly developed T(1)-weighted three-dimensional segmented echo planar imaging (3D EPI) sequence versus a conventional T(1)-weighted three dimensional spoiled gradient echo (3D GRE) sequence in the evaluation of brain tumors. Forty-four patients with cerebral tumors and infections were examined on a 1.0 T MR unit with 23 mT/m gradient strength. The total scan time for the T(1) 3D EPI sequence was 2 min 12 s, and for a conventional 3D GRE sequence it was 4 min 59 s. Both sequences were performed after administration of a contrast agent. The images were analyzed by three radiologists. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, signal-to-noise and contrast-to-noise-ratio (C/N) were calculated. The gray-white differentiation and C/N ratio of 3D EPI were found to be inferior to conventional 3D GRE images, but the difference was not statistically significant. In the qualitative comparison, lesion detection and conspicuity of 3D EPI images and conventional 3D GRE images were similar, but a tow-fold reduction of the scanning time was obtained. With the 3D EPI technique, a 50% scan time reduction could be achieved with acceptable image quality compared to conventional 3D GRE. Thus, the 3D EPI technique could replace conventional 3D GRE in the preoperative imaging of brain.

[Interventions in infrainguinal bypass grafts]. / Interventionen an infrainguinalen Bypässen.

The long-term success of infrainguinal bypass grafts depends on meticulous surgical technique and a periodic program of postoperative surveillance. Duplex scanning is the method of choice for the detection of stenotic lesions that threaten graft patency. As an alternative to surgery, PTA is gaining increasing acceptance for the treatment of non-recurrent, short, and single stenotic lesions, despite somewhat controversial opinions. The initial technical success rates for PTA were reported to be up to 100 %, and a 5-year primary assisted patency rate of up to 65 % has been achieved. Some authors favorize intra-arterial infusion of fibrinolytic agents for the treatment of bypass graft occlusion with technical success rates of up to 92 %. In addition to a reduced trauma compared to surgical thrombectomy, of the venous wall the advantage of thrombolytic therapy is clot lysis in run-off vessels, and uncovering of the stenotic lesions. This stenosis may then be treated by an endovascular or surgical approach.

[Simple and effective rt-PA thrombolysis design]. / Einfaches und effektives rt-PA Thrombolyse-Design.

PURPOSE: Assessment of a novel, simple and practical thrombolysis scheme for the purposes of a central hospital. MATERIALS AND METHODS: 314 thromboembolic lower extremity occlusions in 260 consecutive patients were treated by thrombolysis as follows: 6 ml rt-PA/h for 30 min; 3 ml rt-PA/h for another 30 min; 1 ml rt-PA/h for 7 hours, and 0.4 ml rt-PA until vessel patency. Antegrade introduction of a 5 F straight end-hole catheter through a 6 F, constantly heparin-flushed sheath, to the level of occlusion was followed by subsequent advancement of the catheter tip according to progress of lysis at time intervals of 2, 4, and 8 hours. The regimen was continued overnight. RESULTS: 82% of arterial occlusions were completely recanalized at the end of thrombolysis. Then, angioplasty was performed if appropriate. Best results (100% recanalization rate) were achieved by treating occlusions of the superficial femoral artery, even in cases of involvement of the entire length of the vessel, and isolated popliteal occlusions. A recanalization rate of 70% was achieved by treating distal crural vessel occlusion. Bypass grafts were recanalized in 50%. COMPLICATIONS: 3 x major hematoma, 2 x transluminal perforation; 16 x minor hematoma from the puncture site at the sheath, 4 x erythema, obviously reaction to rt-PA (together n = 25; 8%). CONCLUSIONS: We empirically found and solidly evaluated an effective thrombolysis scheme. Our results demonstrate that major advances are possible even in this well-grounded field.

[PTA versus Palmaz stent placement in femoropopliteal artery stenoses: results of a multicenter prospective randomized study (REFSA)]. / PTA versus Stent bei Stenosen der A. femoralis und A. poplitea: Ergebnisse einer prospektiv randomisierten Multizenterstudie (REFSA).

PURPOSE: To evaluate whether stent placement is superior to percutaneous transluminal angioplasty (PTA) in the treatment of chronic symptoms in short femoropopliteal arterial stenoses. MATERIALS AND METHODS: One hundred twenty-four limbs in 116 patients, who ranged in age from 39 to 87 years (mean age, 67 years), were randomized to PTA (n = 53) versus PTA followed by implantation of long-medium Palmaz-Stents (n = 71). Inclusion criteria were intermittent claudication or chronic critical limb ischemia, short stenosis or occlusion (lesion length < or = 5 cm), and at least one patent run-off vessel at angiography. The follow-up included clinical assessment, measurement of ankle/brachial index (ABI), color duplex ultrasound, and/or angiography at 6, 12 and 24 months. Angiographic follow-up between 12 and 36 months was available in 54 limbs (45 %). RESULTS: Initial technical success was achieved in 50 of 53 limbs (94.4 %) in the PTA group versus 70 of 71 limbs (98.6 %) in the stent group. Overall, major complications occurred in 9.5 % (n = 11), with n = 4 in the PTA group compared to n = 7 in the stent group. No difference was found between the groups of treatment: clinical success at 1 and 2 years was 80.5 and 77.1 % in the PTA group versus 78.1 and 71.0 % in the stent group. The cumulative 1-year and 2-year angiographic primary patency rates were 66.1 and 49.1 % in the stent group versus 76.1 and 66.1 % in the PTA group. The secondary 1-year and 2-year angiographic patency rates were 88.5 and 53.3 % in the stent group versus 82.7 % and 76.2 % in the PTA group. CONCLUSION: The primary success rate was slightly higher after stent placement than after PTA. However, the angiographic, clinical and hemodynamic success after 1 and 2 years tends to be slightly better for PTA.

Accuracy of MDCT in the determination of supraaortic artery stenosis using DSA as the reference standard.

PURPOSE: Accurate stenosis quantification in the carotid arteries is of great clinical importance. We aimed to compare the diagnostic accuracy of multi-slice computed tomography angiography (CTA) to digital subtraction angiography (DSA) for the detection and grading of atherosclerotic lesions involving the supraaortic arteries. MATERIALS AND METHODS: We retrospectively analyzed 30 patients (10 women; mean age, 67 years). CTA was performed after administration of 100 ml Ultravist 370 (Bayer Schering, Germany), at a flow of 5 ml/s, using a Philips Brilliance 16MDCT scanner (Philips, Best, Netherland) at a collimation of 16 mm×0.75 mm prior to DSA. The supraaortic arteries were divided into 17 segments, and, within each segment, the presence and severity of stenotic or occlusive lesions was determined, based on a four-point scale (0-49%, 50-69%, 70-99%, occlusion), by four independent readers using the NASCET criteria. Sensitivity and specificity of MDCT was calculated for the detection of moderate (50-69%) versus significant stenoses (70-99%) and occlusion. RESULTS: There were 291 segments assessed with both methods. Thirteen lesions were "not assessable" on CTA. DSA identified 53 significant lesions, and CTA 56 significant lesions. With regard to significant lesions, CTA overrated six lesions and underestimated six lesions, resulting in a sensitivity, specificity, and accuracy of 86.4%, 97.6%, and 95.9%, respectively. For the detection of stenoses greater than 50%, sensitivity, specificity, and accuracy were 90.2%, 95.8%, and 94.8%, respectively. CONCLUSIONS: Compared to DSA, CTA shows high accuracy in the detection and grading of lesions involving the supraaortic arteries enabling its use in the detection and treatment planning for stenoses of the supraaortic vessels.

PTA versus carbofilm-coated stents in infrapopliteal arteries: pilot study.

PURPOSE: To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study. METHODS: Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47-80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan-Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions. RESULTS: The inter-reader agreement was high (kappa = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05). CONCLUSION: Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.

Successful type II endoleak closure by subclavian-to-carotid artery transposition after stent-graft placement of a distal aortic arch aneurysm.

Endovascular stent-graft placement has become a safe and effective treatment modality for various diseases of the distal aortic arch as well as of the descending aorta. However, its effectiveness may be limited by various kinds of endoleaks resulting in persistent or recurrent perfusion of the aneurysm sac. Subsequently, systemic pressurization leads to expansion of the aneurysm sac, exposing the patient to a recurrent risk of aneurysm rupture. We report on the case of a 57-year-old male who underwent emergency stent-graft placement in March 2001 due to a contained rupture of a distal aortic arch aneurysm involving the origin of the left subclavian artery. Due to the emergency condition, a subclavian-to-carotid artery transposition had not been performed prior to stent-graft placement. During follow-up the patient developed a type II endoleak originating from the left subclavian artery with consecutive enlargement of the aneurysm sac. The endoleak was successfully treated by subclavian-to-carotid artery transposition.

[Noninvasive vascular diagnosis with magnetic resonance angiography]. / Nicht-invasive Gefässdiagnostik mittels Magnetresonanzangiographie.

Currently contrast medium-enhanced, 3D magnetic resonance angiography enables fast and non-invasive depiction of the arterial vessels in the neck, thorax, abdomen, and limbs, which allows high sensitivity and specificity in the diagnostically evaluation of aneurysms, dissection and arterial stenosis. Intravenous bolus administration of a paramagnetic contrast medium is performed after timing of the bolus arrival time, thus enabling rapid acquisition of 3D datasets with high contrast between vessel lumen and surrounding soft tissue. Thorax and abdomen are examined within one breath-hold, the periphery of the extremities and the supra-aortal vessels can be imagined with longer sequences and even increased spatial resolution. Fast contrast-enhanced 3D magnetic resonance angiography--in combination with flow measurements--carries the potential to replace the additional functional information obtained by conventional digital subtraction angiography.

[PTA vs. stent in femoro-popliteal obstruction]. / PTA versus Stent in der femoropoplitealen Strombahn.

PURPOSE: To evaluate whether primary stenting is superior to balloon angioplasty (PTA) alone in the treatment of femoropopliteal obstructive disease. MATERIALS AND METHODS: Sixty-two patients, 24 female and 38 male, mean age 67 years (39-87) years, were randomized to PTA alone (n = 37) or balloon angioplasty followed by implantation of Palmaz stents (n = 33). Follow-up included clinical assessment, ankle-brachial index (ABI), color duplex ultrasound at 1, 3, 6 and 12 months after intervention and intravenous angiography at 6 or 12 months. RESULTS: We had four cases of primary PTA failures (10.8%) and no early (< 30 days) thrombosis compared to one primary stent failure (3.0%) and three early thromboses (9.0%) in the stent group. Cumulative primary angiographic patency rates (life-table analysis) for PTA alone were 82% and 72% (6 and 12 months, respectively) compared to 81% and 60% for primary stent placement. The secondary angiographic patency were 97% and 88% for PTA and 88% and 72% for stent implantation, respectively. However, there was no significant difference in patency rates. CONCLUSIONS: Despite fewer primary technical failures, mid-term angiographic and clinical patency were not improved by primary stent placement compared to PTA alone.

Contrast-enhanced magnetic resonance angiography in the evaluation of peripheral bypass grafts.

The aim of this study was to determine the potential of contrast-enhanced magnetic resonance (MR) angiography in the evaluation of peripheral bypass grafts. Digital subtraction angiography (DSA) served as a standard of reference. Thirty-five patients with previous bypass graft surgery underwent DSA and contrast-enhanced MR angiography within 2 weeks. MR angiography was performed using a three-dimensional fast gradient-echo sequence after administration of gadopentetate dimeglumine. Every leg was divided into 11 segments and scored in five categories of stenosis. MR angiography findings were compared with those of DSA. A total of 38 bypass grafts and 454 segments in 27 patients were included in the evaluation. In 33 (87%) bypass grafts stenosis grading with both methods corresponded, and in 5 (13%) cases stenosis was overestimated on MR angiography. Agreement in detection of hemodynamically significant stenosis (stenosis =50%) was 94.7% with a sensitivity of 100% and a specificity of 91.3%. In 340 (83.0%) vascular segments there was conformity in graduation, in 69 (16.88%), there was a difference of one or more grades on MR angiograms. Forty-four segments (9.6%) were not assessable due to technical limitations. Contrast-enhanced MR angiography is an useful noninvasive tool in the detection of failing peripheral vascular bypass grafts.

Simple and effective technique of guided biopsy in a closed MRI system.

BACKGROUND: Magnetic resonance (MR)-guided biopsies are generally regarded as complex interventions. We implemented interventional MR (IMR) with the resources available in and for practical application in a large (1100 beds) central hospital. METHODS: This simple and straightforward IMR technique uses a step-by-step approach for localization, access route planning, biopsy, verification in at least two planes, and postoperative control. The technique has been used and evaluated unchanged for more than 400 punctures and interventions. RESULTS: Contrast, signal, matrix options, and visibility of needle track and tip permit uncomplicated orientation. The mean duration of a biopsy is 19 min. The technique can be applied to all radiologic puncture settings without any technical or medical complications. CONCLUSION: The crucial step in implementing IMR is not to contemplate its application but to simply start applying the procedure.

Primary implantation of polyester-covered stent-grafts for transjugular intrahepatic portosystemic stent shunts (TIPSS): A pilot study.

PURPOSE: To investigate whether placement of a polyester-covered stent-graft increases the primary patency of transjugular intrahepatic portosystemic stent shunts (TIPSS). METHODS: Between 1995 and 1997 Cragg Endopro or Passager MIBS stent-grafts were used for the creation of TIPSS in eight male patients, 35-59 years of age (mean 48 years). All patients suffered from recurrent variceal bleeding and/or refractory ascites due to liver cirrhosis. Seven stent-grafts were dilated to a diameter of 10 mm, one to 12 mm. Follow-up was performed with duplex ultrasound, clinical assessment, and angiography. RESULTS: The technical success rate for creation of a TIPSS was 100%. The mean portosystemic pressure gradient decreased from 25 mmHg to 12 mmHg. In seven of eight patients TIPSS dysfunction occurred between 2 days and 3 years after stent-graft placement. In one patient the TIPSS is still primarily patent (224 days after creation). The secondary patency rates are 31 days to 3 years. CONCLUSION: The primary use of polyester-covered stent-grafts for TIPSS did not increase primary patency rates in our small series.

[Percutaneous radiologically-guided vertebroplasty in the treatment of osteoporotic and tumorous spinal body lesions]. / Perkutane, radiologisch gesteuerte Vertebroplastie zur Therapie osteoporotischer und tumoröser Wirbelkörperläsionen.

Vertebroplasty is a radiological intervention for the augmentation of bone lesions with bone cement. Main indications are the treatment of osteoporotic vertebral body fractures, however also the treatment of tumorous lesions becomes more and more established. The indication for vertebroplasty of tumorous lesions is therapy-refractory pain in symptomatic hemangiomas, metastases and myelomas. By minimal invasive therapy stabilization of vertebral bodies and pain reduction may be achieved.

Kinetics of apoptosis and secondary necrosis in cultured rat thymocytes and S.49 mouse lymphoma and CEM human leukemia cells.

Cell culture systems are widely used to study metabolic changes during apoptosis. In cell culture, unlike in vivo, apoptotic cells are not phagocytosed and eventually lyse (secondary necrosis). This is of practical importance because metabolic changes seen in cultures may be due to the transition from apoptosis to necrosis, rather than to the induction of apoptosis itself. In the present study, we followed the kinetics of the occurrence of several indicators of cell death in rat thymocytes and mouse lymphoma (S.49), and human leukemia (CEM) cell cultures after dexamethasone treatment (10(-6) M). The presence of apoptosis and secondary necrosis was demonstrated by electron microscopy. Nuclear condensation and fragmentation, which are considered to reflect early stages of apoptosis, were visualized with Hoechst fluorescent dye H 33258 for quantitative determination by light microscopy. In S.49 and CEM cultures their incidence increased after glucocorticoid treatment, but remained at relatively low levels not exceeding 6-9% until 36 h (S.49) or 3-4% until 92 h (CEM). The trypan blue positive cells, however, increased steadily to about 60%. Furthermore, flow cytometry (single parameter DNA analysis after propidium iodide staining) revealed the occurrence of cells with reduced DNA fluorescence. Morphological and biochemical (internucleosomal DNA cleavage) analysis of FACS-sorted cells showed that early after dexamethasone the majority of them were apoptotic. In S.49 and CEM cell cultures no clear-cut time lag between increase in cells with reduced DNA fluorescence, chromatin condensation/fragmentation, and the uptake of trypan blue could be detected.(ABSTRACT TRUNCATED AT 250 WORDS)

rt-PA thrombolysis in acute thromboembolic upper-extremity arterial occlusion.

PURPOSE: Retrospective analysis of the results of rt-PA thrombolysis in the treatment of acute thromboembolic occlusion of the upper limb. METHODS: Of 55 patients with demonstrated acute embolic arterial occlusion, rt-PA thrombolysis was performed on 40 occlusions in 38 patients (23 women with a mean age of 62 years, range 32-85 years; 15 men with a mean age of 65 years, range 32-92 years) according to the following design: 6 mg rt-PA/hr for 30 min, 3 mg rt-PA/hr for the next 30 min, 1 mg rt-PA/hr for 7 hr, and 0.4 mg rt-PA/hr until the end of lysis. Onset of symptoms varied from 1 to 14 days. Included were three isolated upper-arm occlusions, nine combined brachial and forearm occlusions, and 28 forearm and hand artery occlusions. RESULTS: The overall success rate was 55%. The lysis results for isolated upper arm, combined brachial and forearm occlusions, and forearm and hand artery occlusions were 100%, 66%, and 46%, respectively. In eight patients surgical embolectomy had to be performed after failed thrombolysis. No amputation was required in the follow-up period. No lethal complications occurred. CONCLUSIONS: Interventional rt-PA treatment of proximal upper-extremity arterial occlusions may be performed with comparable success rates to surgical embolectomy and without severe complications. For distal occlusions the results are inferior to the success rates obtained with surgery.

Creation of transjugular intrahepatic portosystemic shunts with stent-grafts: initial experiences with a polytetrafluoroethylene-covered nitinol endoprosthesis.

PURPOSE: To evaluate the safety and performance of a recently developed expanded polytetrafluoroethylene (ePTFE)-covered nitinol stent-graft to create transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension and related complications. MATERIALS AND METHODS: The ePTFE-covered nitinol stent-graft was used to create TIPS in 16 patients with recurrent variceal bleeding (n = 13) or refractory ascites (n = 3). Follow-up was performed with duplex ultrasonography, clinical assessment, and venography at 6 months. Technical success and portosystemic pressure gradients (PPGs) before and after stent-graft implantation and at follow-up were assessed. Two patients died during follow-up. Histopathologic follow-up data were available for one patient at autopsy and for the other after liver transplantation. RESULTS: The implantation technical success rate was 100%. Mean (+/- SD) PPG was reduced from 24 mm Hg +/- 5 to 9 mm Hg +/- 2. Histopathologic analysis of the explanted endoprostheses revealed no inflammatory response or neointima formation. The venographic follow-up data available for 10 patients demonstrated 100% in-graft patency (mean follow-up, 289 days +/- 26). Revisions with implantation of a new ePTFE-covered nitinol stent-graft or another commercially available stent in 10 patients were necessary because of hepatic vein stenosis above the grafted portion and/or relative diameter mismatch causing TIPS dysfunction. CONCLUSION: The ePTFE-covered nitinol stent-graft was used successfully to create TIPS and has the potential to prolong TIPS patency upon complete coverage to the hepatocaval junction.