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Dive into the research topics where Alexander M. Prusa is active.

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Featured researches published by Alexander M. Prusa.


Journal of Endovascular Therapy | 2012

Type II endoleaks after endovascular repair of abdominal aortic aneurysms: fate of the aneurysm sac and neck changes during long-term follow-up.

Richard Nolz; Harald Teufelsbauer; Ulrika Asenbaum; Dietrich Beitzke; Martin Funovics; Andreas Wibmer; Christina Plank; Alexander M. Prusa; Johannes Lammer; Maria Schoder

Purpose To evaluate the frequency of type II endoleaks after endovascular aneurysm repair (EVAR) and to compare sac diameter and neck changes in patients with type II endoleak to endoleak-free patients with at least 3-year imaging follow-up. Methods Among 407 consecutive EVAR patients, 109 patients (101 men; mean age 72.1 years, range 55–86) had at least 3-year computed tomography (CT) data and no type I or III endoleak. In this cohort, 49 patients presented with a type II endoleak at some time and 60 patients had no endoleak. Patients with type II endoleaks were further divided into subgroups based on the vessel origin and the perfusion status (persistent or transient). The course of the perfusion status of type II endoleaks and changes in the aneurysm sac diameters, neck diameters, and renal to stent-graft distances (RSD) were evaluated in the defined groups. Reintervention and death rates were also reported. Results The mean follow-up was 68.1±23.8 months. Compared to the no endoleak group, overall sac diameter increased significantly in the type II endoleak group (p=0.007), but vessel origin did not have any influence. With regard to the perfusion status of type II endoleaks, aneurysm sac changes were significantly higher (p = 0.002) in the persistent endoleak group. During the study period, the increase in the proximal neck diameter was significantly higher in the no endoleak group compared to the type II endoleak group (p=0.025). No significant difference was found in RSD changes between the defined groups. Reinterventions were performed in 20 (18.3%) patients (13 for type II endoleak); 2 (1.8%) patients without type II endoleak died of ruptured aneurysm. Conclusion Persistent type II endoleaks led to significant aneurysm sac enlargement, but without increased mortality or rupture rates.


Archives of Surgery | 2008

Improved Survival After Abdominal Aortic Aneurysm Rupture by Offering Both Open and Endovascular Repair

Andreas Wibmer; Maria Schoder; Klaus S. Wolff; Alexander M. Prusa; Maryana Sahal; Johannes Lammer; Ihor Huk; Peter Polterauer; Georg Kretschmer; Harald Teufelsbauer

BACKGROUND In the treatment of ruptured abdominal aortic aneurysm (rAAA), the results of open graft replacement (OGR) have remained constant but discouraging for the last 4 decades. Provided suitable anatomy, elective endovascular abdominal aortic aneurysm repair (EVAR) is less invasive and leads to improved perioperative mortality. Thus, it is reasonable to assume that endovascular treatment should improve the results of rAAA therapy. OBJECTIVE To determine whether the use of both endovascular and open repair of rAAA leads to improved results. DESIGN A single-center, retrospective analysis of 89 patients suffering from rAAA treated either by EVAR or OGR. PATIENTS From October 1999 until July 2006, a consecutive series of patients with rAAA were analyzed. Time was divided into 2 periods of 41 months. During the first period, 42 patients were treated by OGR exclusively. Period 2 started with the availability of an EVAR protocol to treat rAAA; 31 patients received open repair while 16 patients underwent EVAR. MAIN OUTCOME MEASURES Kaplan-Meier survival estimates were calculated and compared. RESULTS Survival estimates showed a statistically significant reduction in overall postoperative mortality following the introduction of EVAR (P < .03). The 90-day overall mortality rate was reduced from 54.8% to 27.7% during the second period (P < .01). Survival of patients older than 75.5 years was especially improved (75% vs 28.6%; P < .01). There was a parallel pattern of significant reduction of the mortality rate after OGR to 29% (P < .03). CONCLUSION Offering both EVAR and OGR to patients with rAAA leads to significant improvements in postoperative survival.


Journal of Endovascular Therapy | 2005

Endografting increases total volume of AAA repairs but not at the expense of open surgery: experience in more than 1000 patients.

Klaus S. Wolff; Alexander M. Prusa; P. Polterauer; Andreas Wibmer; Maria Schoder; Johannes Lammer; Georg Kretschmer; Ihor Huk; Harald Teufelsbauer

Purpose: To compare the volume of open graft replacements (OGR) for abdominal aortic aneurysm (AAA) versus endovascular aneurysm repairs (EVAR) over time and after modifying selection criteria. Methods: A review was conducted of 1021 consecutive patients who underwent AAA repair from 1989 through 2002: 496 elective OGRs for infrarenal AAAs (STANDARD), 289 elective EVARs for infrarenal AAAs, 59 complex OGRs for suprarenal AAAs, and 177 emergent OGRs for ruptured AAAs. Patients from 1995 to 2002 were divided into 2 groups based on shifting treatment strategies; 454 patients were treated by STANDARD or EVAR at the surgeons discretion between 1995 and 2000 (post EVAR). The second group comprised 161 patients treated in 2001–2002 after the introduction of “high-risk” screening criteria (age ≥72 years, diabetes mellitus, renal dysfunction, impaired pulmonary function, or ASA class IV) that dictated EVAR whenever anatomically feasible. For comparison, 170 STANDARD repairs performed in the 6 years prior to EVAR served as a control. Results: While surgery for ruptured AAAs remained fairly stable over the 14-year period, the number of patients undergoing elective repair increased due to the implementation of EVAR. During the 6 years after its introduction, EVAR averaged 34.3 patients per year; after 2001, the annual frequency of EVAR increased to 41.5 (p>0.05). In like fashion, the rate of STANDARD repairs increased to 41.3 patients per year versus 28.3 before EVAR (p=0.032). ASA class IV patients increased by almost 9 fold in the recent period versus pre EVAR (p= 0.006). The overall mortality after elective infrarenal AAA repair decreased between the pre and post EVAR periods (6.5% versus 3.7%, p>0.05) and fell still further to 1.2% in the most recent period (p=0.021 versus pre EVAR). Conclusions: The implementation of an EVAR program increases the total volume of AAA repairs but does not reduce open surgical procedures. By allocating patients to EVAR or open repair based their risk factors, mortality was markedly reduced.


The Annals of Thoracic Surgery | 2012

Light-Induced Vasodilation of Coronary Arteries and Its Possible Clinical Implication

Christian A. Plass; Hans G. Loew; Bruno K. Podesser; Alexander M. Prusa

BACKGROUND Low-level laser therapy and light-emitting diodes (LED) are increasingly used in phototherapy. Their therapeutic effects are at least partly mediated by light-induced vasodilation. The aim of this study was to determine the effect of different light sources on coronary arteries. METHODS Porcine left coronary arteries were cut into 4-mm rings that were irradiated either by a semiconductor nonthermal gallium-arsenide diode laser or a noncoherent athermic red light source both with the same energy density up to 16 J/cm(2). After precontraction with 9, 11-dideoxy-11α, 9α-epoxymethano-prostaglandin F(2)α, respective relaxation responses were evaluated. The role of endothelium as well as intracellular pathways was investigated. RESULTS Maximum vasodilation after exposure to laser was observed at 10 J/cm(2) (56.8% ± 1.2%) and decreased to 43.9% ± 2.8% at 16 J/cm(2) (p < 0.003). After adjusting exposure time to achieve equivalent energy densities in the LED group, vessel segments revealed photorelaxation of 52.9% ± 6.5% and 47.5% ± 0.6%, respectively. Vasodilations achieved by either light source were comparable at 10 J/cm(2) (p < 0.574) and 16 J/cm(2) (p < 0.322). Furthermore, vasodilation could be inhibited by administration of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (nitric oxide scavenger) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (guanocyclase inhibitor) but not with L-nitro-arginine methyl ester or deendothelialization. CONCLUSIONS Vessels exposed to either light source showed a remarkable as well as comparable photorelaxation at definite energy densities. This effect is mediated by an intracellular nitric oxide-dependent mechanism. As LED sources are of small size, simple, and inexpensive build-up, they may be used during routine coronary artery bypass surgery to ease suturing of anastomosis by target vessel vasodilation.


Journal of Trauma-injury Infection and Critical Care | 2005

Effect of body armor on simulated landmine blasts to cadaveric legs.

Klaus S. Wolff; Alexander M. Prusa; Andreas Wibmer; Peter Rankl; Wilhelm Firbas; Harald Teufelsbauer

BACKGROUND Antipersonnel landmine protective footwear relies on blast deflection or on exaggerated standoff between the foot and the explosive. Neither design has been tested for clinical effectiveness. METHODS 4 cadaveric lower extremities--3 fitted with a Koflach boot incorporating TABRE (Technology for Attenuating Blast Related Energy) were subjected to controlled blast with charges of up to 100 g trinitrotoluene (TNT). The blasts were recorded by a digital recording system. All legs were X-rayed and underwent computed tomography scanning before and after testing. RESULTS TABRE-protected limbs directly subjected to the blast hyperextended at the knee during firing. Injuries showed a pattern of open tibial fractures (Gustilo grade I, II), of multiple calcaneal (Sanders Type III, IV), and fibular fractures and of the tibial plateau, but showed no traumatic amputation. CONCLUSIONS Development of protective footwear against landmine blast is feasible. From medium mines up to charges of 100 g TNT limb salvage may be possible.


Clinical Radiology | 2014

Diagnostic workup of primary sclerosing cholangitis: The benefit of adding gadoxetic acid-enhanced T1-weighted magnetic resonance cholangiography to conventional T2-weighted magnetic resonance cholangiography

Richard Nolz; Ulrika Asenbaum; Maria Schoder; Andreas Wibmer; H. Einspieler; Alexander M. Prusa; Markus Peck-Radosavljevic; Ahmed Ba-Ssalamah

AIM To evaluate the value of gadoxetic acid-enhanced T1-weighted (T1W) magnetic resonance cholangiography (MRC) versus conventional T2-weighted (T2W) MRC compared to endoscopic retrograde cholangiopancreatography (ERCP) in patients with primary sclerosing cholangitis (PSC). MATERIALS AND METHODS Based on T1W MRC, PSC patients were classified into a regular (RG) and a delayed (DG) excreting group, with an absence of gadoxetic acid in the common bile duct at 20 min. Beading, pruning, and gradation of central bile duct stenosis, evaluated by T1W and T2W MRC, were compared to ERCP. Liver parenchymal enhancement was measured in both study groups and compared to a reference group (n = 20) without a history of liver disease. Two readers performed all measurements. RESULTS Based on beading and pruning of the peripheral bile ducts, sensitivities, specificities, and accuracies for reader 1 were 0.17/0.43, 0/0.17, and 0.15/0.31 for T1W MRC, and 0.83/0.86, 1/0.83, and 0.85/0.85 for T2W MRC (p = 0.004). For reader 2 sensitivities, specificities, and accuracies were 0.25/0.57, 0/0.33, and 0.23/0.46 for T1W MRC, and 0.92/1, 1/0.83, and 0.92/0.92 for T2W MRC (p = 0.012). Compared to ERCP, central bile duct stenoses were significantly overestimated (p < 0.001) by T2W MRC. A significantly lower parenchymal enhancement was found in the DG (n = 7) compared to the RG (n = 13), and compared to the reference group (p < 0.001). CONCLUSION The combined performance of T2W and T1W MRC may provide a comprehensive imaging workup of PSC, including morphological and functional information resulting in optimal management.


Lasers in Surgery and Medicine | 2012

Low-level-laser irradiation induces photorelaxation in coronary arteries and overcomes vasospasm of internal thoracic arteries†‡

Christian A. Plass; Georg Wieselthaler; Bruno K. Podesser; Alexander M. Prusa

As low‐level laser irradiation (LLLI) seems to induce vasodilation besides many other known biological effects, LLLI has been increasingly used in therapy of medical conditions with various irradiation parameters. The aim of this study was to investigate the effect of LLLI on photorelaxation of human coronary and internal thoracic arteries (ITA).


European Journal of Vascular and Endovascular Surgery | 2012

Aortomonoiliac endografting after failed endovascular aneurysm repair: indications and long-term results.

Alexander M. Prusa; Andreas Wibmer; Maria Schoder; Martin Funovics; Johannes Lammer; P. Polterauer; Georg Kretschmer; Harald Teufelsbauer

OBJECTIVES To present long-term results of endoleak/endograft migration treatment by aortomonoiliac (AMI) endografting after failed endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms. DESIGN Post hoc analysis of a prospectively gathered database at a tertiary care university hospital. MATERIALS AND METHODS From March 1995 to November 2010, 23 patients were identified who underwent modification into AMI configuration after failed elective EVAR. Major causes for modification were type I (with/without endograft migration) or type III endoleaks with aneurysm expansion. An average increase in aneurysm size of 1.6 cm (range: -1.5 to 10.5 cm) since initial aneurysm treatment was observed. Interventional outcomes and long-term results were recorded for analysis. RESULTS Technical success rate of AMI endografting was 95.65% (n = 22). All except two endoleaks could be successfully sealed with this manoeuvre (94.44%). Median time to modification was 5.3 years (interquartile range Q1-Q3: 1.3-9.3 years). No intra-operative conversion to open surgery was necessary and mortality was 0%. Median follow-up was 44 months (interquartile range Q1-Q3: 17-69 months). CONCLUSIONS Treatment of graft-related endoleaks/endograft migration by AMI endografting after failed EVAR represents a safe and feasible procedure. This approach broadens the minimal invasive opportunities of aneurysm treatment, and open surgical conversion may be avoided except in selected patients.


European Journal of Radiology | 2012

Complete ten-year follow-up after endovascular abdominal aortic aneurysm repair: Survival and causes of death

Andreas Wibmer; Richard Nolz; Harald Teufelsbauer; Georg Kretschmer; Alexander M. Prusa; Martin Funovics; Johannes Lammer; Maria Schoder

PURPOSE To analyze the hazard and causes of death after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms during a complete ten year follow-up. METHODS This is a retrospective clinical study of 130 consecutive patients undergoing EVAR between 1995 and 1998. One-hundred twenty-one patients (93.1%) were treated with first-generation stentgrafts and nine patients (6.9%) received second-generation devices. All patients completed a follow-up of at least 10 years, unless death occurred before then. Time and causes of death were provided by the Austrian central register of deaths. RESULTS The median follow-up was 7.6 years, and the 130 patients had 968.5 person-years of follow-up. The ten-year mortality rate was 62.3%. Cardiovascular events were the most frequent causes of death, with a 3.9 incidence rate per 100 person-years. Cancer death and death due to other causes occurred in 2.1 and 1.8 cases per 100 person-years, respectively. Lethal late aneurysm rupture happened in 4.6% (n=6), which corresponds to an annual incidence rate of 0.6 per 100 person-years. All of those patients had been treated with first-generation devices. CONCLUSIONS Cardiovascular events were the most frequent cause of death after EVAR, followed by malignancy and other diseases. The risk of dying from secondary rupture was clearly lower than that of death due to other reasons during ten years after EVAR, even in patients with first-generation stentgrafts.


Wiener Klinische Wochenschrift | 2003

[Ruptured abdominal aortic aneurysms: status quo after a quarter century of treatment experience].

Harald Teufelsbauer; Alexander M. Prusa; Klaus Wolff; Marjana Sahal; Thomas Hölzenbein; Georg Kretschmer; Ihor Huk; Peter Polterauer

BACKGROUND Postoperative mortality rates between 40% and 50% have been invariably reported for the treatment of ruptured abdominal aortic aneurysms (rAAA) over the last 50 years. The aim of this analysis was to investigate which patient subgroups benefit from open surgery and in which subgroups a change of treatment strategies should be considered due to lack of improvement despite optimal patient management. PATIENTS AND METHODS From 1980 to 2002 a total of 230 patients underwent surgery because of a ruptured AAA. The observation period was divided into 3 intervals to achieve an approximately equal distribution of patients. The effect of the observation period and of baseline parameters on mortality rates were investigated. RESULTS Between 1980 and 1990, 72 patients were operated with a mortality rate of 38.9% (n = 28). During the second period (1991-1996) surgery was performed in 72 patients with a mortality rate of 40.3% (n = 29). In the third observation interval (1997-2002) 86 patients underwent surgery with an unvaried high mortality rate of 40.7% (n = 35). By applying a logistic regression model including age, gender, modality of rupture, location of cross-clamping and type of operation, only the modality of rupture and the patients age, which are uncontrollable by the surgeon, could be shown to have a significant impact. CONCLUSION Summing up these findings, open surgical repair of rAAA only leads to acceptable results when performed in younger patients without supposed comorbidities. Survival appears to be accidental in patients with advanced age and increased prevalence of relevant comorbidities/underlying diseases. Minimally invasive techniques may offer promising treatment options to those patients, as they do in elective interventions.SummaryBackgroundPostoperative mortality rates between 40% and 50% have been invariably reported for the treatment of ruptured abdominal aortic aneurysms (rAAA) over the last 50 years. The aim of this analysis was to investigate which patient subgroups benefit from open surgery and in which subgroups a change of treatment strategies should be considered due to lack of improvement despite optimal patient management.Patients and methodsFrom 1980 to 2002 a total of 230 patients underwent surgery because of a ruptured AAA. The observation period was divided into 3 intervals to achieve an approximately equal distribution of patients. The effect of the observation period and of baseline parameters on mortality rates were investigated.ResultsBetween 1980 and 1990, 72 patients were operated with a mortality rate of 38.9% (n=28). During the second period (1991–1996) surgery was performed in 72 patients with a mortality rate of 40.3% (n=29). In the third observation interval (1997–2002) 86 patients underwent surgery with an unvaried high mortality rate of 40.7% (n=35). By applying a logistic regression model including age, gender, modality of rupture, location of cross-clamping and type of operation, only the modality of rupture and the patient’s age, which are uncontrollable by the surgeon, could be shown to have a significant impactConclusionSumming up these findings, open surgical repair of rAAA only leads to acceptable results when performed in younger patients without supposed comorbidities. Survival appears to be accidental in patients with advanced age and increased prevalence of relevant comorbidities/underlying diseases. Minimally invasive techniques may offer promising treatment options to those patients, as they do in elective interventions.ZusammenfassungHintergrundBei der Behandlung des rupturierten abdominellen Aortenaneurysmas (rAAA) wurde während der letzten 50 Jahre eine nahezu unveränderte Mortalitätsrate zwischen 40% und 50% publiziert. Ziel dieser Analyse war es festzustellen, welche Patientensubgruppen von der offenen Operationstechnik profitieren und bei welchen trotz postulierter Optimierung im Management keine Verbesserung der Mortalitätsrate zu erzielen und damit eine Änderung der Behandlungsstrategie zu erwägen ist.Patienten und MethodenVon 1980 bis 2002 wurden 230 Patienten wegen eines rAAA operative behandelt. Der Beobachtungszeitraum wurde in 3 Intervalle mit annähernd gleichen Patientenzahlen unterteilt. Der Beobachtungszeitraum und grundlegende Basisparameter wurden bezüglich ihres Einflusses auf die Mortalitätsrate untersucht.ErgebnisseZwischen 1980 und 1990 wurden 72 Patienten operiert. Die Gesamt-Mortalitätsrate betrug 38,9% (n=28). Während der zweiten Periode (1991–1996) erfolgte eine operative Sanierung bei 72 Patienten mit einer Gesamt-Mortalitätsrate von 40,3% (n=29). Im dritten Beobachtungszeitraum (1997 bis 2002) wurde bei 86 Patienten eine Operation vorgenommen. Die Mortalitätsrate war mit 40,7% (n=35) unverändert hoch. In einem logistischen Regressionsmodell mit Einbeziehung von Alter, Geschlecht, Rupturmodalität, Klemmort und Operationsart ließ sich nur ein signifikanter Einfluss nicht beeinflussbarer Parameter wie Rupturmodalität und Patientenalter nachweisen.SchlussfolgerungZusammenfassend scheint die konventionelle offene chirurgische Versorgung beim rAAA nur bei jüngeren Patienten, ohne zu vermutende signifikante Begleiterkrankungne, zu vertretbaren ergebnissen zu führen. Bei Patienten im fortgeschrittenem Lebensalter mit entsprechend erhöhter Prävalenz von relevanten Begleit- oder Grunderkrankungen ergibt sich ein schicksalshafter Verlauf. Bei diesen Patienten könnte ein minimal invasives Verfahren ähnlich wie beim Elektiveingriff eine erfolgversprechende Behandlungsalternative eröffnen.

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Andreas Wibmer

Medical University of Vienna

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Maria Schoder

Medical University of Vienna

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Georg Kretschmer

Medical University of Vienna

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Johannes Lammer

Medical University of Vienna

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Richard Nolz

Medical University of Vienna

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P. Polterauer

Medical University of Vienna

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Christian A. Plass

Medical University of Vienna

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Ihor Huk

Medical University of Vienna

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