16 research outputs found
Koponyaűri aneurysmák hemodinamikai elemzése: vérzési kockázat és műtéti hatékonyság = Hemodynamic analysis of intracranial aneurysms: risk of bleeding and efficacy of treatment
Koponyaűri aneurysmák áramlástani elemzĂ©sĂ©t vĂ©geztĂĽk idealizált 2D Ă©s 3D geometriai modelleken valamint valĂłs aneurysmákrĂłl kĂ©szĂĽlt rotáciĂłs angiográfia 3D rekonstrukciĂłjábĂłl kĂ©szĂĽlt vĂ©ges elemes modelleken, számĂtĂłgĂ©pes áramlás szimuláciĂłval. Idealizált modelleken összefĂĽggĂ©st találtunk az aneurysma bemeneti nyĂlásának ("nyak") átmĂ©rĹ‘je illetve terĂĽlete Ă©s az aneurysmán belĂĽli rotáciĂłs áramlás mĂ©rtĂ©ke között. A nyak magassága befolyásolta a kialakulĂł örvĂ©nyáramok helyĂ©t Ă©s számát. A legnagyobb nyĂrĂłerĹ‘ a nyak áramlásirány szerinti távoli pontján lĂ©p fel. ValĂłs aneurysmák vĂ©ges elemes modelljein az áramlási mintát meghatározta, hogy az aneurysma a szĂĽlĹ‘Ă©r kanyarulatának kĂĽsĹ‘ vagy belsĹ‘ ĂvĂ©n, vagy elágazási pontján alakult-e ki, valamint hogy nyaka körkörösen, vagy csak egy oldalon Ă©rinti a szĂĽlĹ‘Ă©r falát. További kĂĽlönbsĂ©get eredmĂ©nyezett az aneurysma legnagyobb magassága Ă©s a szĂĽlĹ‘Ă©r hossztengelye által bezárt szög. Az Ă©rfalat falát körkörösen involválĂł zsákoknál szabálytalan örvĂ©nyáramlást, a szĂĽlĹ‘Ă©rrel párhuzamosan elrendezett aneruysmáknál pedig sugár-áramlást Ă©szleltĂĽnk. UtĂłbbi esetekben az aneurysmzsák távoli fala áramlás elosztĂłkĂ©nt viselkedik. A dynamikus nyomás ilyenkor egyenetlen, az áramláselosztĂł pontnak megfelelĹ‘en kisebb csĂşcsot mutat, mĂg más esetekben a zsák fala mentĂ©n egyenletes. Nem talátlunk egyĂ©rtelmű összefĂĽggĂ©st a nyĂrĂłerĹ‘k eloszlásával kapcsolatban. Mindezek alapján megalapozottan feltehetĹ‘, hogy a körkörös nyakkal eredĹ‘ illetve a szĂĽlĹ‘Ă©r hossztengelyĂ©vel párhuzamosan elrendezett aneurysmák hemodynamikai terhelĂ©se Ă©s vĂ©rzĂ©si kockázata magasabb lehet. | Peri-aneurysmal flow was studied in 2D and 3D idealized geometric models of sidewall aneurysms and on finite element models of real human intracranial aneurysms based on 3D reconstruction of rotational angiographic images using computerized flow simulations. On ideal models, the diameter and surface of the aneurysm?s entrance ("neck") significantly impacted the amount of rotational flow within the aneurysm sac and the heights of neck affected the number and site of intra-aneurysmal vortices. The peak shear stress was found at the upstream edge of the neck. On real aneurysm models, the flow pattern was influenced by the location of aneurysms on the inner or outer surface of a loop of the parent artery, by the limited or circumferential involvement of the parent artery?s wall and by the angle between the parent artery?s main axis and the heights of the aneurysm sac. Vortex flow was found in sidewall aneurysms with limited neck involvement, irregular vortex in those with circumferential involvement and jet flow in aneurysms with a parallel arrangement in relation to the parent artery. Dynamic pressure was unevenly distributed over the wall of the aneurysm in these later cases, while there was no peak of pressure in the others. No firm relationship was found between aneurysm geometry and shear stress distribution. These results suggest that aneurysms in a parallel position to the parent artery and those with circumferential involvement of the parent artery?s wall may have an increased hemodynamic stress and subsequently a higher likelihood of rupture
Anterior communicating artery aneurysm rupture and functional outcome in short-term: clipping versus coiling
Our research aims to assess the change in the grade of responsiveness using the Hunt and Hess score as well as the modified ranking scale in patients suffering from anterior communicating artery rupture. We retrospectively analyzed data from 11-patients who suffered from an anterior communicating artery aneurysm rupture that caused a subarachnoid hemorrhage. Severity was assessed using the Hunt and Hess scale grade and modified ranking scale. Anterior communicating artery rupture caused a subarachnoid hemorrhage in 40.81% of all aneurysm ruptures that took place at the Circle of Willis. Unfortunately, 4-patients deceased (3.4%) at a median age of 52-years (range 34-75-years), three of which deceased after coiling and one after clipping. In 71-patients (61.2%) endovascular coiling was performed - 33-males and 38-females - and in the remaining 45-cases, (38.8%) clipping was indicated - 24-males and 21-females. Overall, the pre-interventional median Hunt and Hess scale was 2, which remained after the intervention. When relating the outcome score to the intervention performed, we found that the Hunt and Hess scale score was 3 before coiling and 2 before clipping, whereas afterward, there was a slight increase to 2 and 2, respectively. The modified ranking scale was 2 after clipping, respectively, coiling (P = 0.218). No significant differences were observed between the different groups. Our results show that clipping is as effective as coiling in terms of the Hunt and Hess scale and the rate of mortality in the short-term
Supplex libellus, ad sacratissimam Romanorum imperatoriam, ac Germaniae, Hungariae, Bohemiae regiam majestatem directus, et per mgf. D. Nyáry praesentatus
A biológiai indikátorok információ-tartalmának felhasználása Budapest környezeti viszonyainak értékelésére
Az ipari tevékenység, közlekedés, valamint a különböző fűtőanyagok felhasználása következtében Budapest talajában és a fák leveleiben mind több (és mind nagyobb mennyiségben) toxikus elem mutatható ki.
Számos fafaj levele (mint bio-akkumulátor) a terhelés mértékétől függően képes az egyes elemeket nagyobb mennyiségben felhalmozni. Biológiai indikációjuk alapján meghatározható Budapest egyes területeinek immissziós terhelése, ill. az emberi egészségre toxikus elemek előfordulása
Long-term effectiveness of an ad hoc tailored titanium implant as a spacer for microvascular decompression in the treatment of trigeminal neuralgia caused by megadolichoectatic basilar artery anomaly: 9-year follow-up
Statistical evaluation of measured biomechanical properties of human brain aneurysm samples
Background and purpose – Human brain aneurysms may often prove fatal if not re cognized in time and treated accordingly. The understanding of development and rupture of aneurysms can significantly be im proved by the application of numerical mod elling, which in turn, requires the knowledge of mechanical properties of vessel wall. This study aims to identify assumed differences with respect to age, sex, spatial orientation, and rupture by utilizing detailed statistical analysis of uniaxial tensile measurements of human brain aneurysm samples, performed by the authors in a previous project. Methods – At surgery of 42 patients, aneu rysm fundi were cut distally to the clip. In each case, depending on size, varying num ber of stripes (altogether 88) were prepared and uniaxial stressstrain measurements were performed. Quantities related to the capacity, energy absorption or stiffness were determined and statistically analysed. Results – The number of specimens in the aneurysm sample was sufficient to establish statistical differences with respect to sex and rupture (p<0.05). No significant differences were detected in orientation, though higher values of stresses and deformations were ob tained in the circumferential direction com pared to the meridional direction. Conclusion – Significant differences bet ween sexes with respect to ultimate defor mations were demonstrated according to expectation, and the hypothesis on equal ity of energy capacity could be supported. Similarity of curves with respect to specimen orientation was also observed and ruptured aneurysm sacs tended to be smaller in size. It seems that differences and trends de scribed in this paper are realistic and need to be applied in numerical modelling
Szomszédos csigolyatörések előfordulása percutan vertebroplastica után = Frequency of adjacent vertebral fractures following percutaneous vertebroplasty
Háttér és célkitűzés:
A percutan vertebroplastica (PVP) rendkĂvĂĽl hatĂ©kony mĂłdszer az osteoporoticus csigolyatörĂ©sek okozta fájdalom csökkentĂ©sĂ©ben. A beavatkozás után azonban a betegek egy rĂ©sze Ăşjabb kompressziĂłs törĂ©st szenved. A vizsgálat cĂ©lja az Ăşjabb törĂ©sek gyakoriságának felmĂ©rĂ©se, valamint a PVP okozati szerepĂ©nek becslĂ©se volt a kezelt betegcsoportban.
Betegek Ă©s mĂłdszer:
A retrospektĂv vizsgálatban áttekintettĂĽk az 5 Ă©s fĂ©l Ă©v alatt, csontritkulás talaján csigolyatörĂ©st szenvedett Ă©s PVP-vel kezelt, egymást követĹ‘ betegek adatait. A vizsgálati csoportot a teljes populáciĂł azon tagjai alkották, akik a csigolyastabilizáciĂł után Ăşjabb törĂ©st szenvedtek. A vizsgálat elsĹ‘dleges vĂ©gpontja a PVP után kialakult Ăşjabb törĂ©sek elĹ‘fordulásának gyakorisága volt. A másodlagos vĂ©gpontot a korábban kezelt csigolyákkal szomszĂ©dos szegmentumokban, 90 napon belĂĽl kialakult Ăşjabb törĂ©sek kĂ©peztĂ©k, ugyanis ebben a csoportban feltĂ©telezhetĹ‘ leginkább a PVP biomechanikai kiváltĂł szerepe.
Eredmények:
Ă–sszesen 396 beteget kezeltĂĽnk PVP-vel osteoporoticus csigolyatörĂ©s miatt. Az átlagĂ©letkor 68±11 Ă©v volt. A betegek 77%-a nĹ‘. Ă–sszesen 73 beteg szenvedett a PVP után Ăşjabb törĂ©st (vizsgálati csoport), amely a teljes populáciĂł 18,4%-át kĂ©pezte. Ebben a csoportban egy fĹ‘re átlagosan 3,8 csigolyatörĂ©s jutott. A PVP-vel szomszĂ©dos törĂ©sek szignifikánsan gyakrabban fordultak elĹ‘, mint a távoli szegmentumot Ă©rintĹ‘ fracturák. Ă–sszesen 44 beteg szenvedett szomszĂ©dos csigolyatörĂ©st a PVP utáni 90 napon belĂĽl, Ĺ‘k a teljes populáciĂł 11%-át kĂ©pviseltĂ©k. A teljes populáciĂłhoz viszonyĂtva ebben a csoportban szignifikánsan kevesebb volt a fĂ©rfi.
Következtetés:
PVP után közel minden ötödik betegnek van arra esĂ©lye, hogy Ăşjabb törĂ©st szenvedjen, azonban a korábban elvĂ©gzett csigolyastabilizáciĂłnak valĂłszĂnűleg csak minden tizedik betegnĂ©l lesznek biomechanikai következmĂ©nyei, egy Ăşjabb fractura formájában. A legnagyobb kockázatĂşak a több törĂ©st szenvedett, sĂşlyos csontritkulásban szenvedĹ‘ nĹ‘betegek.
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Introduction and aims:
Percutaneous vertebroplasty (PVP) proved to be very effective in the treatment of pain caused by osteoporotic vertebral compression fractures. A certain proportion of patients, however, suffer a new fracture after treatment. Our purpose was to analyze the frequency of new fractures, and to estimate the causative role of PVP in the treated population.
Methods:
The retrospective study reviewed all consecutive patients treated with PVP for osteoporotic compression fractures during a 5.5 years period. The study group comprised those patients, who suffered a new fracture during the follow up. The primary endpoint was the frequency of new fractures. The secondary endpoint was the occurrence of new fractures in a timeframe of 90 days after treatment that were adjacent to the previously treated segments. The causative role of PVP was estimated to be the highest in this subgroup.
Results:
Altogether 396 consecutive patients were treated with PVP for osteoporotic compression fractures. Mean age was 68+11 years, and 23% of the population was male. The study group comprised 73 patients (18.4%). In this subgroup the patients had an average of 3.8 vertebral fractures. After PVP, adjacent fractures were significantly more likely, than distal fractures. Altogether 44 patients (11% of the entire population) suffered an adjacent fracture in 90 days after PVP. In this group there were significantly less male patients as compared to the entire population.
Conclusions:
After PVP almost every fifth patient is at risk for developing a new fracture, however, it is likely to be related to the vertebral augmentation in every tenth subject only. Female patients with severe osteoporosis are probably facing the highest risk for developing new fractures