Safety and Efficacy of Baseline Antiplatelet Treatment in Patients Undergoing Mechanical Thrombectomy for Ischemic Stroke: Antiplatelets Before Mechanical Thrombectomy.

PURPOSE: To investigate the safety and efficacy of baseline antiplatelet treatment in patients with acute ischemic stroke (AIS) undergoing mechanical thrombectomy (MT). MATERIALS AND METHODS: Baseline use of antiplatelet medication before MT for (AIS) may provide benefit on reperfusion and clinical outcome but could also carry an increased risk of intracranial hemorrhage (ICH). All consecutive patients with AIS and treated with MT with and without intravenous thrombolysis (IVT) between January 2012 and December 2019 in all centers performing MT nationwide were reviewed. Data were prospectively collected in national registries (eg, SITS-TBY and RES-Q). Primary outcome was functional independence (modified Rankin Scale 0-2) at 3 months; secondary outcome was ICH. RESULTS: Of the 4,351 patients who underwent MT, 1,750 (40%) and 666 (15%) were excluded owing to missing data from the functional independence and ICH outcome cohorts, respectively. In the functional independence cohort (n = 2,601), 771 (30%) patients received antiplatelets before MT. Favorable outcome did not differ in any antiplatelet, aspirin, and clopidogrel groups when compared with that in the no-antiplatelet group: odds ratio (OR), 1.00 (95% CI, 0.84-1.20); OR, 1.05 (95% CI, 0.86-1.27); and OR, 0.88 (95% CI, 0.55-1.41), respectively. In the ICH cohort (n = 3,685), 1095 (30%) patients received antiplatelets before MT. The rates of ICH did not increase in any treatment options (any antiplatelet, aspirin, clopidogrel, and dual antiplatelet groups) when compared with those in the no-antiplatelet group: OR, 1.03 (95% CI, 0.87-1.21); OR, 0.99 (95% CI, 0.83-1.18); OR, 1.10 (95% CI, 0.82-1.47); and OR, 1.43 (95% CI, 0.87-2.33), respectively. CONCLUSIONS: Antiplatelet monotherapy before MT did not improve functional independence or increase the risk of ICH.

Clinical Question Influence on Radiation Dose of Cardiac CT Scan in Children.

Background: To assess the impact of different clinical questions on radiation doses acquired during cardiac computed tomography in children. Methods: A total of 116 children who underwent cardiac CT on a third-generation dual-source CT scanner were included. The clinical questions were divided into three main categories: the extent of scanning in the z-axis, coronary artery assessment and cardiac function assessment. Radiation dose values represented as a dose-length product (DLP) in mGy*cm were recorded from the CT scanner protocols. Results: There were significantly higher doses in cases with cardiac function assessment (median DLP 348 versus 59 mGy*cm, p < 0.01) and in cases with coronary artery assessment (median DLP 133 versus 71 mGy*cm, p < 0.01). Conclusion: The most important factor was the assessment of cardiac function, where the median radiation dose was 4.3× higher in patients with a request for cardiac function assessment. We strongly recommend that clinical requests for cardiac CT should be carefully considered in the paediatric population.

Fresh Cold-Stored Vascular Allografts in Subgenicular Location: Our Experience with Rescue Endovascular Techniques.

BACKGROUND: Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. CLI is associated with high rates of morbidity and mortality with high risk of limb amputation. In the absence of appropriate autologous grafts, unsuitability of prosthetic bypasses, and endovascular methods, fresh cold-stored venous allografts is an option. Endovascular interventional methods are essential methods for maintaining primary and secondary patency. METHODS: A single-centre retrospective analysis of 82 surgical revascularizations using allogeneic vascular grafts and rescue endovascular techniques restoring and maintaining the patency of these allogeneic revascularizations in the period between July 2005 and July 2021. RESULTS: We have performed 82 allogeneic revascularizations in 75 patients (52 reconstructions in men/63.4%/, 30 reconstructions in women/36.6%/). The median age of patients was 68 years (49 min, 87 max). We subsequently had to intervene a total of 26 bypasses. We intervened in 30 acute occluded allogeneic bypass grafts and 9 failing stenotic bypass grafts. We performed 52 angiographies. The success rate of rescue endovascular procedures in primary allogeneic reconstruction with distal anastomosis to the popliteal artery is statistically significant (P < 0.02) compared to procedures with distal anastomosis to the tibial and pedal bed. The cumulative patency (primary at time) of allogeneic reconstructions in our group was 89% after 1 month, 51.9% after 12 months, 24.2% after 3 years, 9.8% after 5 years. Limb salvage was 72.6% in 1 year, 53% in 3 years, 36.5% in 5 years, respectively. CONCLUSIONS: Cold-stored venous allografts may be used for performing below-the-knee revascularization for CLI with acceptable results, despite the poor long-term patency. Rescue endovascular techniques are an essential method for restoring or maintaining the patency of these reconstructions. These techniques have a high success rate and no other alternative.

Endovascular Treatment of a Life-threatening Blunt Thoracic Aortic Injury in Polytraumatized Patients - A Single Center Experience.

A retrospective analysis of our group of patients, efficacy, safety and the results of endovascular treatment of descending thoracic aorta by using stentgraft implantation in polytraumatized patients. In the period between 6/2006 and 2/2020, in the processing of data, we analysed retrospectively patients with polytrauma diagnosed with thoracic aortic rupture or transection (TAT) and treated with multiple injuries. Clinical characteristics, complications, pathological features, and hospital follow-up data were retrieved from our group. In our group of 28 polytraumatized patients referred to our Trauma Centre with current TAT, all 28 patients with such a thoracic aortic injury were treated by using thoracic stentgraft implantation. In our group of patients, the average Injury Severity Score (ISS) was 22 for women (min 19, max 27) and 26 for men (min 17, max 41), respectively. We reached 100% technical implantation success rate with our patients. In our group, we had 30-day mortality of 10.7% (3 patients) and the in-hospital mortality was 17.8% (5 patients). Surviving patients had calculated ISS score of 25 (min 17, max 41); dead patients had an ISS score of 28 (min 19, max 34) - p≤0.05. Endovascular treatment of TAT, as a minimally invasive and effective procedure with rapid bleeding control, may increase survival chances for severely compromised polytraumatized patients in the context of multiple-organ damage and the need for a major cardio-vascular surgery.

Thrombectomy vs medical management in low NIHSS acute anterior circulation stroke.

OBJECTIVE: To undertake an effectiveness and safety analysis of EVT in patients with LVO and NIH Stroke Scale (NIHSS) score ≤6 using datasets of multicenter and multinational nature. METHODS: We pooled patients with anterior circulation occlusion from 3 prospective international cohorts. Patients were eligible if presentation occurred within 12 hours from last known well and baseline NIHSS ≤6. Primary outcome was modified Rankin Scale (mRS) score 0-1 at 90 days. Secondary outcomes included neurologic deterioration at 24 hours (change in NIHSS of ≥2 points), mRS 0-2 at 90 days, and 90-day all-cause mortality. We used propensity score matching to adjust for nonrandomized treatment allocation. RESULTS: Among 236 patients who fit inclusion criteria, 139 received EVT and 97 received medical management. Compared to medical management, the EVT group was younger (65 vs 72 years; p < 0.001), had more proximal occlusions (p < 0.001), and less frequently received concurrent IV thrombolysis (57.7% vs 71.2%; p = 0.04). After propensity score matching, clinical outcomes between the 2 groups were not significantly different. EVT patients had an 8.6% (95% confidence interval [CI] -8.8% to 26.1%) higher rate of excellent 90-day outcome, despite a 22.3% (95% CI, 3.0%-41.6%) higher risk of neurologic deterioration at 24 hours. CONCLUSIONS: EVT for LVO in patients with low NIHSS score was associated with increased risk of neurologic deterioration at 24 hours. However, both EVT and medical management resulted in similar proportions of excellent clinical outcomes at 90 days. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with acute anterior circulation ischemic strokes and LVO with NIHSS < 6, EVT and medical management result in similar outcomes at 90 days.

Distinctive Patterns of Seizure-Related White Matter Alterations in Right and Left Temporal Lobe Epilepsy.

Background: We hypothesized that right and left temporal lobe epilepsy (RTLE and LTLE, respectively) have distinctive spatial patterns of white matter (WM) changes that can be differentiated and interpreted with the use of multiple diffusion parameters. We compared the global microstructure of fiber bundles with regard to WM alterations in both RTLE and LTLE, addressing some of the methodological issues of previous studies. Methods: Diffusion tensor imaging data from 17 patients with RTLE (age: 40.7 ± 10.4), 15 patients with LTLE (age: 37.3 ± 10.4), and 15 controls (age: 34.8 ± 11.2) were used in the study. WM integrity was quantified by fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity (LD), and radial diffusivity (RD). The diffusion parameters were compared between the groups in tracts representing the core of the fiber bundles. The volumes of hippocampi and amygdala were subsequently compared across the groups, while the data were adjusted for the effect of hippocampal sclerosis. Results: Significantly reduced FA and increased MD, LD, and RD were found bilaterally over widespread brain regions in RTLE. An increase in MD and RD values was observed in widespread WM fiber bundles ipsilaterally in LTLE, largely overlapping with regions where FA was lower, while no increase in LD was observed. We also found a difference between the LTLE and RTLE groups for the right hippocampal volume (with and without adjustment for HS), whereas no significant volume differences were found between patients and controls. Conclusions: It appears that patients with RTLE exhibit a more widespread pattern of WM alterations that extend far beyond the temporal lobe in both ipsilateral and contralateral hemisphere; furthermore, these changes seem to reflect more severe damage related to chronic degeneration. Conversely, more restrained changes in the LTLE may imply a pattern of less severe axonal damage, more restricted to ipsilateral hemisphere. Comprehensive finding of more prominent hippocampal atrophy in the RTLE raises an interesting issue of seizure-induced implications on gray matter and WM microstructure that may not necessarily mean a straightforward causal relationship. Further correlations of diffusion-derived metrics with neuropsychological and functional imaging measures may provide complementary information on underlying WM abnormalities with regard to functional hemispheric specialization.

Mechanical thrombectomy performs similarly in real world practice: a 2016 nationwide study from the Czech Republic.

BACKGROUND: Randomized clinical trials have proven mechanical thrombectomy (MT) to be a highly effective and safe treatment in acute stroke. The purpose of this study was to compare neurothrombectomy data from the Czech Republic (CR) with data from the HERMES meta-analysis. METHODS: Available nationwide data for the CR from 2016 from the Safe Implementation of Treatments in Stroke-Thrombectomy (SITS-TBY) registry for patients with terminal internal carotid artery (ICA) and/or middle cerebral artery (MCA) occlusions were compared with data from HERMES. CR and HERMES patients were comparable in age, sex, and baseline National Institutes of Health Stroke Scale scores. RESULTS: From a total of 1053 MTs performed in the CR, 845 (80%) were reported in the SITS-TBY. From these, 604 (72%) were included in this study. Occlusion locations were as follows (CR vs HERMES): ICA 22% versus 21% (P=0.16), M1 MCA 62% versus 69% (P=0.004), and M2 MCA 16% versus 8% (P<0.0001). Intravenous thrombolysis was given to 76% versus 83% of patients, respectively (P=0.003). Median onset to reperfusion times were comparable: 232 versus 285 min, respectively (P=0.66). A modified Thrombolysis in Cerebral Infarction score of 2b/3 was achieved in 74% (433/584) versus 71% (390/549) of patients, respectively (OR 1.17, 95% CI 0.90-1.5, P=0.24). There was no statistically significant difference in the percentage of parenchymalhematoma type 2 (OR 1.12, 95% CI 0.66-1.90, P=0.68). A modified Rankin Scale score of 0-2 at 3 months was achieved in 48% (184/268) versus 46% (291/633) of patients, respectively (OR 0.92, 95% CI 0.71-1.18, P=0.48). CONCLUSIONS: Data on efficacy, safety, and logistics of MT from the CR were similar to data from the HERMES collaboration.

Thoracic Outlet Syndrome: A Significant Family Genetic Phenotypic Presentation.

We report on a very rare case of diagnosis and successful surgical treatment of three young family members with a four-fold presentation of thoracic outlet syndrome. In the relevant family case, we are considering and discussing the population incidence, a possible HOX genes disorder, and a significant phenotypic presentation.

Difference in white matter microstructure in differential diagnosis of normal pressure hydrocephalus and Alzheimer's disease.

OBJECTIVES: Alzheimer's disease (AD) and normal pressure hydrocephalus (NPH) are both associated with cognitive decline and ventriculomegaly. While promising approach in differentiating between the two diseases, only a few diffusion tensor imaging (DTI) studies compared directly NPH and AD patients. The current study compares global whitematter (WM) alterations in AD and NPH addressing some of the methodological issues of previous studies. PATIENTS AND METHODS: Diffusion tensor images were obtained from 17 patients with NPH, 14 with AD, and 17 healthy controls. White matter integrity was quantified by fractional anisotropy (FA), mean (MD), axial (λ1) and radial diffusivity (RD). The diffusion parameters were compared between the groups in 'skeletonised' tracts representing the core of the fibre bundles. RESULTS: Reduced FA was found in NPH patients throughout the corpus callosum, particularly in the splenium, along with increased RD. On the other hand, FA, MD and RD were higher in NPH in the cortico-fugal fibres arising from the frontal and parietal cortex. While no FA changes were detected in AD patients compared to controls, widespread increased RD was observed. When comparing NPH and AD patients, higher FA, MD and RD was observed in the corona radiata in the periventricular fibres arising from the frontal and parietal cortex in NPH patients. The ventricular volumes were correlated with diffusivity parameters in the tracts next to the ventricles in AD and NPH patients. CONCLUSION: Our analysis identified a pattern of WM diffusion alterations that can differentiate NPH patients from controls and AD patients.

Cortical and subcortical atrophy in Alzheimer disease: parallel atrophy of thalamus and hippocampus.

Brain atrophy is a key imaging hallmark of Alzheimer disease (AD). In this study, we carried out an integrative evaluation of AD-related atrophy. Twelve patients with AD and 13 healthy controls were enrolled. We conducted a cross-sectional analysis of total brain tissue volumes with SIENAX. Localized gray matter atrophy was identified with optimized voxel-wise morphometry (FSL-VBM), and subcortical atrophy was evaluated by active shape model implemented in FMRIB's Integrated Registration Segmentation Toolkit. SIENAX analysis demonstrated total brain atrophy in AD patients; voxel-based morphometry analysis showed atrophy in the bilateral mediotemporal regions and in the posterior brain regions. In addition, regarding the diminished volumes of thalami and hippocampi in AD patients, subsequent vertex analysis of the segmented structures indicated shrinkage of the bilateral anterior thalami and the left medial hippocampus. Interestingly, the volume of the thalami and hippocampi were highly correlated with the volume of the thalami and amygdalae on both sides in AD patients, but not in healthy controls. This complex structural information proved useful in the detailed interpretation of AD-related neurodegenerative process, as the multilevel approach showed both global and local atrophy on cortical and subcortical levels. Most importantly, our results raise the possibility that subcortical structure atrophy is not independent in AD patients.

Prenatal diagnosis of congenital epulis by 2D/3D ultrasound and magnetic resonance.

Congenital epulis is a rare benign oral cavity tumor that usually arises from the maxillary alveolar mucosa. It is also known as congenital gingival granular cell tumor. Prenatal diagnosis is uncommon and mostly confined to the third trimester. We report a case of congenital epulis, which was referred to our department at 35 weeks of gestation. Both images from our prenatal 2D/3D ultrasound (including Doppler technique) and magnetic resonance examination are presented. A baby girl weighing 2,800 g was delivered spontaneously at 36 weeks and 1 day. The newborn had to be intubated immediately after delivery. A simple excision of the mass was performed on the first day of neonatal life after clinical examination by our pediatric stomatologists confirmed the presence of a tumor resembling epulis. The correctness of this diagnosis was subsequently confirmed by histogenesis. Photographs from the operating room show the postnatal appearance of the tumor. The baby was discharged at the age of 19 days and has remained well at follow-up controls.

Diffusion tensor imaging in Alzheimer disease and mild cognitive impairment.

A wide range of imaging studies provides growing support for the potential role of diffusion tensor imaging (DTI) in evaluating microstructural white matter integrity in Alzheimer disease (AD) and mild cognitive impairment (MCI). Our review aims to present DTI principles, post-processing and analysis frameworks and to report the results of particular studies. The distribution of AD-related white matter abnormalities is widely discussed in the light of deteriorated connectivity within certain tracts due to secondary white matter degeneration; primary alterations are also assumed to contribute to the pattern. The question whether it is more effective to assess the whole-brain diffusion or to directly concentrate on specific regions remains an interesting issue. Assessing white matter microstructure alterations, as evaluated by group-level differences of tensor-derived parameters, may be a promising neuroimaging tool for differential diagnosis between AD, MCI and other cognitive disorders, as well as being particularly helpful in the interpretation of underlying pathological processes.

Hepatic intra-arterial injection of drug-eluting bead, irinotecan (DEBIRI) in unresectable colorectal liver metastases refractory to systemic chemotherapy: results of multi-institutional study.

INTRODUCTION: Response rates and overall outcome for patients who have failed first-line and in some cases second-line chemotherapy are as low as 12% and 7 months, respectively. The aim of this study is to evaluate the efficacy of hepatic arterial sulfonate hydrogel microsphere (drug-eluting beads), irinotecan preloaded therapy (DEBIRI) in metastatic colorectal cancer refractory to systemic chemotherapy. METHODS: This was a multicenter multinational single-arm study of metastatic colorectal cancer patients who received DEBIRI after failing systemic chemotherapy from 10/2006 to 8/2008. Primary endpoints were safety, tolerance, tumor response rates, and overall survival. RESULTS: Fifty-five patients who had received prior systemic chemotherapy and who underwent a total of 99 DEBIRI treatments were reviewed. The median number of DEBIRI treatments was 2 (range 1-5), median treatment dose was 100 mg (range 100-200 mg), with total hepatic treatment of 200 mg (range 200-650 mg), with 86% of treatments performed as lobar infusion and 30% of patients treated with concurrent simultaneous chemotherapy. Adverse events occurred in 28% of patients with median grade of 2 (range 1-3) with no deaths at 30 days post procedure. Response rates were 66% at 6 months and 75% at 12 months. Overall survival in these patients was 19 months, with progression-free survival of 11 months. CONCLUSIONS: Hepatic arterial drug-eluting bead, irinotecan (DEBIRI) was safe and effective in treatment of metastatic colorectal cancer (MCC) refractory to multiple lines of systemic chemotherapy. DEBIRI is an acceptable therapy for treatment of metastatic colorectal cancer to the liver.

Bone geometry and volumetric bone mineral density in girls with Turner syndrome of different pubertal stages.

OBJECTIVE: An increased rate of fractures has been reported in patients with Turner syndrome (TS). We aimed to assess bone geometry and volumetric bone mineral density (vBMD) at the radius in girls with TS and to evaluate the relationships between bone parameters and fracture history. METHODS AND DESIGN: Sixty-seven girls with TS aged 6-19 years treated currently or in the past with growth hormone (GH) and/or oestrogens were examined using peripheral quantitative computed tomography. Results were compared to reference data. RESULTS: Cortical area and cortical thickness were low in all age groups (all P<0·001). Height-adjusted total bone area at the diaphysis was increased in prepubertal and postpubertal girls (mean Z-score 1·0, P<0·05 for both) and normal in the pubertal group (mean Z-score 0·1). Cortical vBMD was decreased (mean age-specific Z-scores -2·0, -1·6 and -1·0 for prepubertal, pubertal and postpubertal groups, respectively, P<0·01 for all groups). Height- , age- and cortical thickness-adjusted cortical vBMD was positively correlated to the duration of GH therapy (P=0·012) and to oestrogen administration (P=0·047). Girls with a history of fractures had lower total vBMD at the metaphysis compared to nonfractured TS girls (mean Z-scores -1·7 vs-0·9, P=0·04). CONCLUSIONS: There is a cortical bone deficit in girls with TS characterized by low cortical area, thin cortex and probably decreased cortical vBMD. Early commencement of GH therapy, as well as oestrogen replacement, is associated with higher cortical vBMD. Further studies should investigate the potential causality of this relation.

Transarterial chemoembolisation (TACE) using irinotecan-loaded beads for the treatment of unresectable metastases to the liver in patients with colorectal cancer: an interim report.

BACKGROUND: Following failure of standard systemic chemotherapy, the role of hepatic transarterial therapy for colorectal hepatic metastasis continues to evolve as the experience with this technique matures. The aim of this study to gain a better understanding of the value of drug eluting bead therapy when administered to patients with unresectable colorectal hepatic metastasis. METHODS: This was an open-label, multi-center, single arm study, of unresectable colorectal hepatic metastasis patients who had failed standard therapy from 10/2006-10/2008. Patients received repeat embolizations with Irinotecan loaded beads(max 100 mg per embolization) per treating physician's discretion. RESULTS: Fifty-five patients underwent 99 treatments using Irinotecan drug eluting beads. The median number of total treatments per patient was 2(range of 1-5). Median length of hospital stay was 23 hours(range 23 hours - 10 days). There were 30(30%) sessions associated with adverse reactions during or after the treatment. The median disease free and overall survival from the time of first treatment was 247 days and 343 days. Six patients(10%) were downstaged from their original disease status. Of these, four were treated with surgery and two with RFA.Neither number of liver lesions, size of liver lesions or extent of liver replacement(25%) were predictors of overall survival. Only the presence of extrahepatic disease(p = 0,001), extent of prior chemotherapy (failed 1st and 2nd line vs > 2 line failure)(p = 0,007) were predictors of overall survival in multivariate analysis. CONCLUSION: Chemoembolization using Irinotecan loaded beads was safe and effective in the treatment of patients as demonstrated by a minimal complication rate and acceptable tumor response.

Congenital gastric outlet obstruction by pyloric membrane: prenatal and postnatal diagnosis and management.

Congenital gastric outlet obstruction is a rare condition representing only 1% of all gastrointestinal atresias. Prenatal diagnosis is uncommon and mostly confined to the third trimester of cases presenting a combination of polyhydramnios with dilated stomach. We report a case of congenital gastric outlet obstruction by pyloric membrane which was diagnosed prenatally in the third trimester by sonography and magnetic resonance imaging. The anomaly appeared to be isolated, thus a favorable outcome was expected. A baby girl weighing 3,430 g was delivered spontaneously at 36 weeks. Postnatal imaging methods confirmed the presence of a congenital gastric obstruction. 21 h after delivery, the baby underwent laparotomy, at which time a malrotation and pyloric membrane were found and resolved. The postoperative course was uneventful and the baby was discharged at the age of 18 days and remains well at controls.

Results of a peripheral cutting balloon prospective multicenter European registry in hemodialysis vascular access.

PURPOSE: To report initial experience with the Peripheral Cutting Balloon (PCB) in treatment of failing hemodialysis shunts. METHODS: A total of 190 patients (95 men, 95 women; average age 64.4 +/- 11.9 years, range 32-87 years) who were treated with the PCB for pressure-resistant stenosis, restenosis or failed percutaneous transluminal angioplasty (PTA) in the venous limb of an arteriovenous shunt were followed in seven European centers using a simple registry. The group consisted of 109 de novo lesions (57%) and 79 restenotic lesions (43%). RESULTS: Technical success was achieved in 88.9% of cases. Primary patency was as follows (the results for whole group and simultaneous results for de novo lesions and restenoses are presented): 1 month (140 patients followed): 94%, 98%, and 93%; 3 months (116 patients followed): 93%, 98%, and 92%; 6 months (40 patients followed): 85%, 92%, and 79%; 12 months (27 patients followed): 74%, 87%, and 48%. No complication occurred. Patients experienced an equal or lower level of pain during the procedure compared with conventional PTA. CONCLUSION: The PCB proved to be successful in dilating pressure-resistant stenoses. We cannot conclude whether PCB angioplasty can lower the restenosis rate in hemodialysis access lesions, but the long-term patency for de novo lesions is high. A further randomized study is advisable.

Percutaneous transcatheter one-step mechanical aortic disc valve prosthesis implantation: a preliminary feasibility study in swine.

PURPOSE: To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. METHODS: The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. RESULTS: MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. CONCLUSION: The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.