CT- versus MRI-Based Imaging for Thrombolysis and Mechanical Thrombectomy in Ischemic Stroke: Analysis from the Austrian Stroke Registry.

BACKGROUND AND PURPOSE: It is unclear whether a particular stroke imaging modality offers an advantage for the acute stroke treatment. The aim of this study was to compare procedure times, efficacy and safety of thrombolysis and/or thrombectomy based on computed tomography (CT) versus magnetic resonance imaging (MRI) acute stroke imaging. METHODS: Data of stroke patients who received intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT) were extracted from a nationwide, prospective stroke unit registry and categorized according to initial imaging modality. Study endpoints included procedure times, symptomatic intracerebral hemorrhage (sICH), early neurological improvement, 3-month functional outcome by modified Rankin Scale (mRS) and mortality. RESULTS: Stroke patients (n=16,799) treated with IVT and 2,248 treated with MT were included. MRI-guided patients (n=2,599) were younger, had less comorbidities and higher rates of strokes with unknown onset as compared to CT-guided patients. In patients treated with IVT, no differences were observed regarding the rates of functional outcome by mRS 0-1 (adjusted odds ratio [OR], 0.87; 95% confidence interval [CI], 0.71 to 1.05), sICH (adjusted OR, 0.82; 95% CI, 0.61 to 1.08), and mortality (adjusted OR, 0.88; 95% CI, 0.63 to 1.22). Patients undergoing MT selected by MRI as compared to CT showed equal rates of functional outcome by mRS 0-2 (adjusted OR, 0.87; 95% CI, 0.65 to 1.16), sICH (adjusted OR, 0.9; 95% CI, 0.51 to 1.69), and mortality (adjusted OR, 0.62; 95% CI, 0.35 to 1.09). MRI-guided patients showed a significant intrahospital delay of about 20 minutes in both the IVT and the MT group. CONCLUSIONS: This large non-randomized comparison study indicates that CT- and MRI-guided patient selection for IVT/MT may perform equally well in terms of functional outcome and safety.

[Interdisciplinary position paper: the value of radiofrequency denervation in the treatment of chronic pain]. / Interdisziplinäres Positionspapier: der Stellenwert der Radiofrequenzdenervierung in der Therapie chronischer Schmerzen.

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

Austrian consensus on the definition and treatment of portal hypertension and its complications (Billroth II).

In November 2004, the Austrian Society of Gastroenterology and Hepatology (ÖGGH) held for the first time a consensus meeting on the definitions and treatment of portal hypertension and its complications in the Billroth-Haus in Vienna, Austria (Billroth I-Meeting). This meeting was preceded by a meeting of international experts on portal hypertension with some of the proponents of the Baveno consensus conferences (http://www.oeggh.at/videos.asp). The consensus itself is based on the Baveno III consensus with regard to portal hypertensive bleeding and the suggestions of the International Ascites Club regarding the treatment of ascites. Those statements were modified by new knowledge derived from the recent literature and also by the current practice of medicine as agreed upon by the participants of the consensus meeting. In October 2011, the ÖGGH organized the second consensus meeting on portal hypertension and its complications in Vienna (Billroth II-Meeting). The Billroth II-Guidelines on the definitions and treatment of portal hypertension and its complications take into account the developments of the last 7 years, including the Baveno-V update and several key publications.

Contrast-enhanced MRA of the renal and aorto-iliac-femoral arteries: comparison of gadobenate dimeglumine and gadofosveset trisodium.

RATIONALE AND OBJECTIVES: Dedicated contrast agents are now available for contrast-enhanced magnetic resonance angiography (CE-MRA). This study retrospectively compares the safety and diagnostic performance data from Phase III regulatory trials performed to evaluate gadobenate dimeglumine (MultiHance(®)) and gadofosveset trisodium (Vasovist®)) for renal and peripheral CE-MRA. MATERIALS AND METHODS: Similar examination and blinded assessment methodology was utilized in all studies to determine the safety and diagnostic performance of the agents for detection of significant (>50%) steno-occlusive disease. Digital Subtraction Angiography (DSA) was used as the standard of truth. Diagnostic performance data (sensitivity, specificity, predictive values [PVs], and likelihood ratios [LRs]) were compared (Chi-square test). RESULTS: CE-MRA with gadobenate dimeglumine was more specific (92.4% vs. 80.5%, p < 0.0001) and accurate (83.6% vs. 77.1%, p = 0.022) than CE-MRA with gadofosveset in the detection of significant renal artery stenosis. The average sensitivity was higher for gadofosveset (74.4% vs. 67.3%, p = 0.011) in peripheral vessels although gadobenate dimeglumine was more specific (93.0% vs. 88.2%, p < 0.0001) with no difference in accuracy (86.6% vs. 86.3%, p = 0.66). PPVs were higher (p < 0.0001) for gadobenate dimeglumine in both vascular territories. Pre- to post-test shifts in the probability of detecting significant disease were greater after gadobenate dimeglumine. Adverse events in the renal and peripheral studies were reported by 9.2% and 7.7% of patients after gadobenate dimeglumine compared with 30.3% and 22.1% of patients after gadofosveset. CONCLUSION: The diagnostic performance of CE-MRA for the detection of significant steno-occlusive disease is similar with gadofosveset and gadobenate dimeglumine although the rate of adverse events appears higher with gadofosveset.

Multicenter, double-blind, randomized, intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for MR angiography of peripheral arteries.

PURPOSE: To prospectively compare the image quality and diagnostic performance achieved with doses of gadobenate dimeglumine and gadopentetate dimeglumine of 0.1 mmol per kilogram of body weight in patients undergoing contrast material-enhanced magnetic resonance (MR) angiography of the pelvis, thigh, and lower-leg (excluding foot) for suspected or known peripheral arterial occlusive disease. MATERIALS AND METHODS: Institutional review board approval was granted from each center and informed written consent was obtained from all patients. Between November 2006 and January 2008, 96 patients (62 men, 34 women; mean age, 63.7 years +/- 10.4 [standard deviation]; range, 39-86 years) underwent two identical examinations at 1.5 T by using three-dimensional spoiled gradient-echo sequences and randomized 0.1-mmol/kg doses of each agent. Images were evaluated on-site for technical adequacy and quality of vessel visualization and offsite by three independent blinded readers for anatomic delineation and detection/exclusion of pathologic features. Comparative diagnostic performance was determined in 31 patients who underwent digital subtraction angiography. Data were analyzed by using the Wilcoxon signed-rank, McNemar, and Wald tests. Interreader agreement was determined by using generalized kappa statistics. Differences in quantitative contrast enhancement were assessed and a safety evaluation was performed. RESULTS: Ninety-two patients received both agents. Significantly better performance (P < .0001; all evaluations) with gadobenate dimeglumine was noted on-site for technical adequacy and vessel visualization quality and offsite for anatomic delineation and detection/exclusion of pathologic features. Contrast enhancement (P < or = .0001) and detection of clinically relevant disease (P < or = .0028) were significantly improved with gadobenate dimeglumine. Interreader agreement for stenosis detection and grading was good to excellent (kappa = 0.749 and 0.805, respectively). Mild adverse events were reported for four (six events) and five (eight events) patients after gadobenate dimeglumine and gadopentetate dimeglumine, respectively. CONCLUSION: Higher-quality vessel visualization, greater contrast enhancement, fewer technical failures, and improved diagnostic performance are obtained with gadobenate dimeglumine, relative to gadopentetate dimeglumine, when compared intraindividually at 0.1-mmol/kg doses in patients undergoing contrast-enhanced MR angiography for suspected peripheral arterial occlusive disease.

CT-guided ozone/steroid therapy for the treatment of degenerative spinal disease--effect of age, gender, disc pathology and multi-segmental changes.

INTRODUCTION: Oxygen-ozone nucleolysis (ONL) is a new, minimally invasive procedure for the treatment of discogenic low back pain with or without radicular symptoms. The aim of the present study was to determine associations between the morphology of the basic disease, patient-specific factors and the outcome of the treatment. MATERIALS AND METHODS: Six hundred and twelve patients not responding to conservative therapy were divided into five groups (disc bulging, disc herniation, postoperative patients, osteochondrosis, others) and subjected to nucleolysis with ozone and to periradicular infiltration with steroids and local anaesthesia. The success of treatment was assessed by means of a visual analog pain scale (VAS) and the Oswestry Disability Index (ODI). RESULT: A significant reduction in the VAS was registered after 2 and 6 months (from 8.6 to 5.4 and 6.0; p < 0.001) in all patient groups; an excellent therapy response (VAS below 3.0) was achieved by about a third of the patients. A significant improvement in ODI was registered in all patients (46 to 31; p < 0.001), most pronounced in the herniation group (25.5, p = 0.015). Patients below 50 years had significantly better values in the VAS and ODI score 6 months after treatment. Final VAS and ODI scores for patients with a single diseased segment were 4.2 and 28.0, in two affected segments 6.5 and 32 and in three segments 6.7 and 38.5 (p < 0.001 and p = 0.051). CONCLUSION: ONL with periradicular steroid therapy might exert a functional and sustained analgesic effect in patients with degenerative changes in the lumbar spine not responding to conservative therapy and was most effective below 50 years with disc herniation in one segment.

Safety and efficacy of gadofosveset-enhanced MR angiography for evaluation of pedal arterial disease: multicenter comparative phase 3 study.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of gadofosveset, a gadolinium-based albumin-binding MRI contrast agent, in patients with pedal arterial disease. SUBJECTS AND METHODS: A total of 185 adult patients with known or suspected pedal arterial disease were randomized in a group receiving 0.03 mmol/kg and a group receiving 0.05 mmol/kg of gadofosveset for MR angiography of the pedal arteries. Gadofosveset-enhanced and unenhanced time-of-flight MR angiograms were compared with conventional angiograms, the standard of reference, for the presence of vascular stenosis. All patients underwent drug safety analysis. RESULTS: For each of three blinded readers, the specificity (21-35%) of gadofosveset-enhanced MR angiography was a statistically significant (p < 0.010) improvement over that of unenhanced MR angiography in the detection of clinically significant (> 50%) stenosis. The sensitivities of the two techniques were similar. For all blinded readers of MR angiograms, sensitivity, specificity, and accuracy were higher with use of the 0.03-mmol/kg dose of gadofosveset than with the 0.05-mmol/kg dose. In the 0.03-mmol/kg group, 28% of patients reported a total of 50 adverse events, 96% of which were reported as mild or moderate. In the 0.05-mmol/kg group, 28% of patients reported a total of 55 adverse events, 98% of which were reported as mild or moderate. No patients died; one patient left the study because of myocardial infarction considered unrelated to the study drug. CONCLUSION: Because of markedly better efficacy than no contrast agent and a minimal and transient side-effect profile, 0.03 mmol/kg of gadofosveset was found safe and effective for MR angiography of patients with pedal arterial disease.

Diagnostic performance of gadobenate dimeglumine enhanced MR angiography of the iliofemoral and calf arteries: a large-scale multicenter trial.

OBJECTIVE: The purpose of this study was to compare gadobenate dimeglumine-enhanced MR angiography and unenhanced time-of-flight MR angiography for the detection of significant peripheral arterial occlusive disease using digital subtraction angiography as our reference standard. SUBJECTS AND METHODS: Two hundred seventy-two patients underwent MR angiography and digital subtraction angiography of the iliofemoral arteries. MR angiography was performed before (2D time-of-flight acquisitions) and after (spoiled gradient-echo acquisitions) the administration of 0.1 mmol/kg of gadobenate dimeglumine at 1-2 mL/s. Contrast-enhanced MR angiography and digital subtraction angiography of the calf arteries were performed in 241 of 272 participants. Images were evaluated on-site and by four blinded reviewers (three for MR angiography, one for digital subtraction angiography). Comparative diagnostic performance for the detection of significant (> or = 51% vessel lumen narrowing) disease was evaluated using the McNemar test and generalized estimating equations. Interobserver agreement was assessed with generalized kappa statistics. The chi-square test was used to compare technical failure rates. RESULTS: Digital subtraction angiography confirmed significant disease (597 stenoses, 386 occlusions) in 983 iliofemoral segments. The sensitivity (54-80.9%), specificity (89.7-95.3%), and accuracy (85-87.5%) of contrast-enhanced MR angiography for the detection of significant iliofemoral disease were significantly (p < 0.001, all reviewers) better than those of time-of-flight MR angiography (33.2-62.8%, 74.3-88.9%, and 68-77.3%, respectively). Similar diagnostic performance was obtained for the calf arteries. The technical failure rate with contrast-enhanced MR angiography (2.5-3.4%) was similar to that of digital subtraction angiography (1.4%) and significantly (p < 0.001) lower than that of time-of-flight MR angiography (6.2-18.0%). Significantly better reproducibility (p < 0.001) was obtained with contrast-enhanced MR angiography (82% vs 65.2% agreement; kappa = 0.66 vs 0.45). CONCLUSION: Improved diagnostic performance and reproducibility are achievable with gadobenate dimeglumine-enhanced MR angiography in patients with peripheral arterial occlusive disease.

Gadobenate dimeglumine-enhanced MR angiography: Diagnostic performance of four doses for detection and grading of carotid, renal, and aorto-iliac stenoses compared to digital subtraction angiography.

PURPOSE: To determine the diagnostic performance of contrast-enhanced MR angiography (CE-MRA) with four doses of gadobenate dimeglumine for detection of significant steno-occlusive disease of the carotid, renal, and pelvic vasculature. MATERIALS AND METHODS: Eighty-four patients with suspected disease of the renal (n = 16), pelvic (n = 41), or carotid (n = 27) arteries underwent CE-MRA (3D-spoiled gradient-echo sequences) at 1.5T. CE-MRA was performed with gadobenate dimeglumine at 0.025, 0.05, 0.1, or 0.2 mmol/kg (23, 24, 19, and 18 patients, respectively) administered at 2 mL/sec. Accuracy, sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) for detection of significant disease (>50% stenosis or occlusion for renal/pelvic arteries; >70% stenosis or occlusion for carotid arteries) was determined by three fully blinded, independent radiologists using conventional digital subtraction angiography (DSA) as reference standard. All comparisons were tested statistically (ANOVA, chi-square, and Mantel-Haenszel tests as appropriate) and reader agreement (kappa) was assessed. RESULTS: Values for accuracy, sensitivity, specificity, PPV, and NPV on CE-MRA were consistently higher for 0.1 mmol/kg gadobenate dimeglumine (accuracy = 95.2-97.3%, sensitivity = 84.2% (all readers), specificity = 96.9-99.2%, PPV = 80.0-94.1%, NPV = 97.6-97.7%). The greater accuracy of the 0.1 mmol/kg dose was significant (P < 0.01, all readers) compared to all other dose groups. Agreement between the three readers was good for all dose groups (kappa >/=0.58), with the highest percent agreement (85.7%) noted for the 0.1 mmol/kg dose. CONCLUSION: Significantly better diagnostic performance on CE-MRA of the renal, pelvic, and carotid arteries is achieved with a gadobenate dimeglumine dose of 0.1 mmol/kg bodyweight.

Abdominal and iliac arterial stenoses: comparative double-blinded randomized study of diagnostic accuracy of 3D MR angiography with gadodiamide or gadopentetate dimeglumine.

PURPOSE: To prospectively evaluate accuracy of gadolinium-enhanced three-dimensional (3D) magnetic resonance (MR) angiography with gadodiamide and gadopentetate dimeglumine (0.1 mmol/kg), with intraarterial DSA as reference standard, for imaging abdominal and iliac arterial stenoses. MATERIALS AND METHODS: The study was approved by all institutional review boards; informed consent was obtained from each subject before procedures. Two hundred forty-seven subjects were included; 240 received either contrast agent and were available for safety analysis; 222 were available for accuracy analysis. Enhanced 3D MR angiography and DSA were performed; image data were evaluated in a double-blinded randomized study. Stenoses were classified as not relevant (<50% stenosis) or relevant (> or =50%). For detection of main stenosis, accuracy with enhanced 3D MR angiography compared with that with DSA was determined. RESULTS: The difference in accuracy for imaging with gadodiamide and gadopentetate was 3.6%. Noninferiority was inferred because the lower bound of the exact two-sided 95% confidence interval was -10.1 and was above the noninferiority margin (-15%). Accuracy for detection of the main stenosis was low, 56.4% for gadodiamide and 52.8% for gadopentetate group. Subgroup analysis with exclusion of inferior mesenteric artery and internal iliac arteries and the most false-positive stenosis classifications yielded better results: 76.6% and 71.6%, respectively. Sensitivity, specificity, and negative and positive predictive values did not differ substantially between study groups. In the main analysis, values were 44%, 96%, 35%, and 97% for gadodiamide and 44%, 83%, 30%, and 90% for gadopentetate, respectively. In the subgroup analysis, values were 66%, 95%, 61%, and 96% for gadodiamide and 63%, 86%, 58%, and 88% for gadopentetate, respectively. CONCLUSION: Noninferiority of gadodiamide versus gadopentetate was verified based on the primary end point, which was accuracy for detection of the main stenosis with enhanced 3D MR angiography compared with DSA.

MRA of the carotid arteries.

Magnetic resonance angiography (MRA) is increasingly used as a non-invasive method to assess carotid arteries. Contrast-enhanced MRA (CE-MRA) has benefited from rapid technological developments, including specific hardware and pulse sequence design. In the evaluation of stenoses of the extracranial internal carotid artery (ICA), CE-MRA using "first generation" CE-MRA gadolinium (Gd)-based chelates can be a substitute for conventional digital subtraction angiography (DSA), although CE-MRA tends to overestimate the degree of stenosis. Studies describing the use of high-relaxivity contrast agents like gadobenate dimeglumine (Gd-BOPTA) reveal that this agent is safe and well tolerated for CE-MRA. The use of Gd-BOPTA shows significantly better quantitative and qualitative performance than carotid CE-MRA using first generation Gd-based chelates. In fact, CE-MRA with Gd-BOTPA provides information comparable to that attainable with rotational DSA. In conclusion, high-relaxivity contrast agents combined with dedicated MRA software appear to be optimal for achieving high-quality evaluation of the carotid arteries.

MRA versus DSA in the assessment of occlusive disease in the aortic arch vessels: accuracy in detecting the severity, number, and length of stenoses.

PURPOSE: To compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (MRA) to that of digital subtraction angiography (DSA) in the detection, grading, and measurement of atherosclerotic stenoses involving the aortic arch arteries. METHODS: The MRA and DSA studies from 28 patients (16 women; mean age 61.6 years, range 24-83) being evaluated for possible aortic arch vessel disease were examined. The aortic arch vasculature was divided into 9 segments; within each segment, the presence and severity of stenotic or occlusive disease was determined based on a 5-point scale. In addition, stenosis length and distance to the branch were measured in 5-mm increments. Image quality was assessed using a 5-point scale. The accuracy, sensitivity, and specificity values, as well as the positive and negative predictive values in MRA's identification of lesions, were evaluated in comparison to DSA. RESULTS: In 28 patients, 189 segments were assessed by both methods. Of these, 173 were correctly rated by MRA, resulting in an accuracy of 91.5%. The accuracy dropped slightly to 86.5% when 11 "not assessable" lesions were included. Sensitivity and specificity for severity measurement were 88.5% and 95.6%, respectively. In 39 of 45 lesions, stenosis length measurements were identical by both methods, but there was a difference of 0.5 cm each in 6 lesions. CONCLUSIONS: MRA as compared to DSA shows high accuracy in the detection and grading of lesions involving the aortic arch vessels. The noninvasive nature of this method recommends its use for screening, treatment planning, and follow-up in known or suspected arterial disease in aortic arch arteries.

Contrast material-enhanced, moving-table MR angiography versus digital subtraction angiography for surveillance of peripheral arterial bypass grafts.

PURPOSE: To assess the accuracy of moving-table MR angiography (MRA) in the evaluation of peripheral bypass grafts. MATERIALS AND METHODS: There were 39 patients who had had peripheral bypass graft surgery and then subsequently underwent digital subtraction angiography (DSA) and contrast material-enhanced MRA, which was performed with moving-table software on a 1.0-T system before and during administration of 40 mL gadolinium. For evaluation, every bypass graft was divided into three parts and every leg into 14 segments. Disease severity was scored in four categories (0%-29%, 30%-69%, 70%-99%, 100%). Results were compared with those of the DSA. A total of 147 bypass graft segments and 938 vessel segments were classified. RESULTS: In 132 of the assessable 147 bypass segments, disease gradings with both methods were congruent; however, 13 stenoses were misinterpreted by MRA for one grade and two additional lesions by two grades, leading to an accuracy in precise stenoses detection of 89.9%. The sensitivity and specificity values in the detection of bypass graft stenoses >69% (grade 3 + 4 lesions) reached 90.0% and 98.3%, respectively. In 821 of 938 vessel segments the accuracy of MRA in stenoses detection reached 87.5%. The sensitivity and specificity values in the detection of grade 3 + 4 lesions were 95.6% and 94.0% for the native vessels, respectively. CONCLUSION: Moving-table MRA was as accurate in assessing bypass grafts as it was for the native arteries and showed a great accuracy in stenosis detection compared with DSA. Therefore, MRA is a promising modality for bypass graft surveillance and might be a noninvasive alternative to DSA in this regard.

Gadobutrol-enhanced moving-table magnetic resonance angiography in patients with peripheral vascular disease: a prospective, multi-centre blinded comparison with digital subtraction angiography.

The purpose of this study was to compare moving-table three-dimensional contrast-enhanced magnetic resonance angiography (CE MRA), using 1.0-mol gadobutrol, with intra-arterial digital subtraction angiography (i.a. DSA) for evaluation of pelvic and peripheral arteries in patients with peripheral arterial occlusive disease. A total of 203 patients were examined in a prospective, multi-centre study at 1.0/1.5 T. Ten vessel segments of one leg were evaluated on-site and by three independent blinded reviewers off-site. One hundred eighty-two patients were evaluable in blinded reading. For pelvis and thigh, there was statistically significant diagnostic agreement between CE MRA and i.a. DSA on-site (94%) and off-site (86-88%). Overall, for detection of clinically significant stenoses, 93% sensitivity and 90% specificity were achieved in on-site evaluation, with 71-76 and 87-93% off-site; for detection of occlusion, sensitivity and specificity on-site were 91 and 97%, with 75-82 and 94-98% off-site. Evaluation was more sensitive on-site than off-site for detection of stenoses and occlusion, whereas specificity was similar. The CE MRA with 1.0-mol gadobutrol gave results comparable to those of i.a. DSA for the larger arteries of pelvis and thigh. Results for calf arteries were compromised by spatial resolution and technical limitations.

Permanent transarterial embolization of neuroendocrine metastases of the liver using cyanoacrylate and lipiodol: assessment of mid- and long-term results.

OBJECTIVE: The purpose of our study was to assess the results of hepatic artery embolization using N-butyl-2-cyanoacrylate and ethiodized oil for the treatment of small-bowel neuroendocrine metastases to the liver as part of a multimodality protocol for the treatment of liver metastases from neuroendocrine small-bowel tumors. MATERIALS AND METHODS: Twenty-three patients underwent permanent embolization of the hepatic artery using cyanoacrylate and Lipiodol for treatment of liver metastases after radical resection of small-bowel neuroendocrine tumors. All patients received additional treatment including somatostatin, and most patients received interferon as well. Cumulative survival rates were estimated using the Kaplan-Meier method. RESULTS: Overall, 75 embolizations (range, 1-10; mean, 3.3) were performed. Median survival time was 69 months, and the estimated cumulative survival rates reached 95.7% and 65.4% for 1 and 5 years, respectively. Two deaths (8.7%) occurred within 1 month of treatment, and one patient experienced a vascular complication at the time of embolization. CONCLUSION: Permanent embolization of hepatic arteries as part of a multimodality treatment protocol is beneficial in long-term follow-up for patients with metastasized small-bowel neuroendocrine tumors. The use of cyanoacrylate as an embolic agent is safe and effective.

Elective endovascular stent-graft repair of atherosclerotic thoracic aortic aneurysms: clinical results and midterm follow-up.

OBJECTIVE: The purpose of this study was to evaluate the clinical and midterm results after endovascular treatment of atherosclerotic thoracic aortic aneurysms. MATERIALS AND METHODS: Twenty-eight consecutive patients who were 53-82 years old (mean age, 71.6 years) were treated with a commercially available endoprosthesis. Subclavian transposition or bypass surgery was performed before the procedure in eight patients. Size dynamics of the aneurysms were analyzed on the basis of diameter and thrombus volume measurements obtained on three-dimensional CT reconstructions before hospital discharge (n = 22) and at the 1-year (n = 22), 2-year (n = 12), and 3-year (n = 5) follow-ups. RESULTS: The technical success rate was 100%. There was no 30-day mortality. None of the patients had symptoms due to spinal cord ischemia. The survival rate at 1, 2, and 3 years was 96.1%, 90.9%, and 80.2%, respectively. During the perioperative period, patients presented with leukocytosis (37%), fever (36%), elevated C-reactive protein value (92%), pleural effusion (50%), and periaortic atelectasis (41%). Three early type I endoleaks sealed spontaneously. Three early type II endoleaks persisted over time, and one late type II endoleak was detected. In patients with type II endoleaks, thrombus volume of the aneurysms was constant (n = 2) or increased (n = 2). In patients without endoleaks, mean thrombus volume decreased (-53.2 +/- 56.8 mL, -40%) significantly (p = 0.001) during the first year. There was no significant interval decrease between the 1- and 2-year follow-ups (mean, -2.4 mL, p = 0.92) and between the 2- and 3-year follow-ups (mean, -0.4 mL, p = 0.68). CONCLUSION: Endovascular treatment of atherosclerotic thoracic aortic aneurysms may result in a substantial reduction of the aneurysm sac in patients without endoleaks.

Peripheral vascular occlusive disease: evaluation with contrast-enhanced moving-bed MR angiography versus digital subtraction angiography in 106 patients.

OBJECTIVE: The purpose of our study was to compare contrast-enhanced moving-bed MR angiography and digital subtraction angiography in the evaluation of peripheral vascular occlusive disease. MATERIALS AND METHODS: This retrospective report includes 106 patients (45 women, 61 men) with known or suspected peripheral vascular occlusive disease who underwent MR angiography and intraarterial digital subtraction angiography of the peripheral arteries. MR angiography was performed on a 1.0-T unit using a moving-bed technique. Every leg was divided into 14 vascular segments, and severity of disease was scored in four categories. Digital subtraction angiography was the standard of reference. RESULTS: In the 106 patients, 2378 vessel segments were evaluated with both imaging modalities. In 2156 segments, MR angiography and digital subtraction angiography were concordant for stenosis classification, in 188 segments the two modalities differed in one category, and in 24 segments they differed in two categories. MR angiography achieved sensitivity and specificity of 96.7% and 95.8%, respectively, for differentiating nonsignificant from hemodynamically significant stenosis (kappa = 0.91). CONCLUSION: This study indicates that MR angiography is an accurate imaging modality in clinical practice. Our data support the concept that MR angiography can modify the diagnosis of suspected peripheral vascular occlusive disease.

MR angiography vs CT angiography in the follow-up of nitinol stent grafts in endoluminally treated aortic aneurysms.

Our objective was to evaluate the accuracy of contrast-enhanced 3D MR angiography (MRA) in the follow-up of patients with endoluminally treated aortic aneurysms and correlate these findings with uni- or biphasic CT angiography (CTA). Forty MR angiograms in 32 patients with implanted aortic nitinol stent grafts were compared to CTA. Twenty-two MR examinations were correlated with arterial-phase CTA (uniphasic), and 18 MR examinations were correlated with biphasic CTA. Uniphasic CTA demonstrated three type-1/type-3 endoleaks and four reperfusion (type-2) endoleaks. In addition, MRA depicted two type-2 reperfusion endoleaks that were missed by CTA. Using biphasic CTA, two type-1/type-3 endoleaks and three reperfusion (type-2) endoleaks were detected; of those, delayed scanning detected three reperfusion (type-2) endoleaks missed during arterial-phase CTA. In addition to the findings by CTA, MRA depicted another type-2 reperfusion endoleak. Magnetic resonance angiography is at least as sensitive as uni- or biphasic CTA for detecting endoleaks and may consequently offer advantages in patients with contraindications to iodinated contrast agents.

Imaging of aortic stent-grafts and endoleaks.

Although the technical success of stent-graft implantation is established and relatively safe, data on the long-term safety and efficacy of endovascular repair are just emerging. Because several late complications of aortic stent-graft placement have been observed, life-long follow-up remains essential. Imaging methods form an integral part of every stage of endovascular aortic aneurysm repair. The current imaging strategy should include initial plain films, CT angiography, and color-coded Duplex sonography. Plain films are an excellent means to detect migration, angulation, kinking, and structural changes of the stent mesh, including material fatigue, at follow-up. Helical CT angiography is considered a potentially revolutionary method for the noninvasive complete postprocedural assessment of aortic sten-grafting. Current data justify the use of biphasic C angiography as the postprocedural imaging technique of choice in most patients [118]. Ultrasound offers the advantages of low cost and lack of radiation exposure. High-quality ultrasound reliably excludes endoleaks in patients after stent-grafting of AAAs. There is a substantial variability, however, in measuring the diameter of aneurysm sacs; thus, confirmation using an alternative study is prudent in cases that demonstrate a significant change in size during follow-up. MR angiography serves as an attractive alternative to CT angiography in patients with impaired renal function or known allergic reaction to iodinated contrast media. With current techniques, the visualization of aortic stent-grafts (with the exception of stainless-steel-based devices) is sufficient with MR angiography. There is evidence that MR imaging is superior to CT angiography in detecting small type 2 endoleaks or for excluding retrograde perfusion in patients with suspected endotension. The role of diagnostic catheter angiography is limited to assessment of vascular pathways in equivocal cases or for suspected endotension. Currently, a consensus view about postprocedural management after aortic stent-graft implantation is lacking. The authors propose performing a baseline CT angiography at discharge and a biphasic CT angiography and Duplex ultrasound scan at three months. In patients with no evidence of an endoleak, CT angiography, plain film and Duplex sonography (abdomen) should be repeated every year after endovascular repair. If an endoleak is present at follow-up, immediate appropriate treatment should be initiated.

Endovascular stent grafting versus open surgical operation in patients with infrarenal aortic aneurysms: a propensity score-adjusted analysis.

BACKGROUND: Although transfemoral endovascular aneurysm management (TEAM) of infrarenal abdominal aortic aneurysms (AAA) is widely performed, open graft replacement is still considered the standard of care. The aim of this study was to investigate whether clear indications for TEAM can be established in patients with significant comorbidities without investigating differences in relative procedure efficacy or durability. METHODS AND RESULTS: A propensity score-based analysis of 454 consecutive patients treated electively for AAA from January 1995 through December 2000 was performed. Of those 454 patients, 248 received open surgery and 206 received TEAM. In-hospital mortality rates (MRs) were compared. After adjusting for propensity scores, a Cox proportional hazard model (COX) was employed to test the influence of the respective treatment on postoperative 900-day survival estimates (SEs). Several potential preoperative risk factors were used as covariates. The MR of all patients was 3.7%. Explorative analysis demonstrated that patients treated by TEAM presented with significantly more risk factors. In American Society of Anesthesiologists class IV patients, a significant difference in MR was detected (4.7% for TEAM versus 19.2% for open surgery; P<0.02). After adjusting for the propensity to receive TEAM or open surgery, a regression analysis of survival based on COX revealed predictive influences of impaired kidney (P<0.047) or pulmonary function (P<0.001), increased age (P<0.05), and selection of treatment modality (P<0.002) on SE. CONCLUSIONS: TEAM represents a less invasive procedure for AAA therapy in patients with significant preoperative risk factors. Especially in geriatric patients with multiple morbidities, TEAM offers a method of therapy with acceptable MRs and SEs, making active treatment possible in otherwise incurable patients.