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Dive into the research topics where Monika Killer-Oberpfalzer is active.

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Featured researches published by Monika Killer-Oberpfalzer.


Interventional Neuroradiology | 2012

Coiling after treatment with the woven EndoBridge cerebral aneurysm embolization device. A case report.

A.K. Wallner; E. Broussalis; T. Hauser; Eugen Trinka; Monika Killer-Oberpfalzer

Retreatment options after the use of the newly launched Woven EndoBridge cerebral aneurysm embolization device (WEB II) are mostly unknown. Nine months after WEB II implantation, a 55-year-old female patient presented with regrowth of an MCA aneurysm. For the first time, standard balloon-assisted coiling was used to close the regrown aneurysm proximal to the WEB II implant. We report on the feasibility and safety of balloon-assisted coiling after implantation of the WEB II device.


Journal of NeuroInterventional Surgery | 2016

Ignoring floor and ceiling effects may underestimate the effect of carotid artery stenting on cognitive performance

Martin Scherr; Alexander Kunz; Anselm Doll; Johannes Sebastian Mutzenbach; Erasmia Broussalis; Hans Jürgen Bergmann; Margarita Kirschner; Eugen Trinka; Monika Killer-Oberpfalzer

Introduction Data on neuropsychological outcome after carotid artery stenting (CAS) remain inconsistent, furthermore cognitive outcome seems to be unpredictable in the individual case. Previous studies reporting improvement or decline might be due to ceiling and floor effects of the applied cognitive tests. We applied cognitive testing before and after CAS, avoiding the pitfall of ceiling and floor effects. Methods In our prospective database, we identified 72 patients free of clinical stroke with ≥70% carotid artery stenosis, who were treated with CAS. They were administered a neurocognitive test battery before and 3 months after CAS to compare cognitive performance before and after CAS. To avoid ceiling and floor effects of test performances, we additionally analysed subgroups of patients without baseline floor and ceiling cognitive performance. Results Pre-interventional to post-interventional cognitive performance improved significantly in the subtests measuring verbal episodic memory; deterioration was observed in spatial memory. The subgroups of patients without baseline floor and ceiling cognitive performance improved in measures of global cognition, verbal episodic memory (patients with left-sided CAS) and divided attention (patients with right-sided CAS); we observed no significant effects in the other domains. Conclusions Ignoring floor and ceiling effects may underestimate the impact of CAS on cognitive performance.


Interventional Neuroradiology | 2015

Therapeutic challenges after successful thrombectomy in a patient with an antiphospholipid syndrome associated M1-occlusion: A case report

Katharina Stadler; Johannes Sebastian Mutzenbach; Gudrun Kalss; Johann Sellner; Abdul R Al-Schameri; Eugen Trinka; Monika Killer-Oberpfalzer

Backround Stroke is a frequent disorder in patients with an antiphospholipid syndrome (APS). Due to a high risk for further thromboembolic events, appropriate anticoagulation therapy in patients with an APS-associated stroke seems mandatory but drug eluting and duration is a matter of debate. Case A 48-year-old female patient presented with Broca’s aphasia and mild hemiparesis on the right side. Diagnostic work-up revealed left middle cerebral artery (MCA) occlusion yet without diffusion-weighted lesions. Due to a thrombocytopenia (67.00 g/l) systemic thrombolysis was not indicated and endovascular treatment was initiated 150 min after symptom onset. After successful clot retrieval, recurrent re-occlusions lead to the necessity of stent implantation and anticoagulation, respectively. On day 5 she developed a new severe right-sided hemiparesis. The magnetic resonance imaging (MRI) showed a subtotal restenosis of the left MCA despite the regular anticoagulation regime leading to a new left MCA ischaemic stroke. In the meantime, the unknown aetiology, the patients’ age and the thrombocytopenia let to further diagnostic workup. Elevated blood parameters such as lupus anticoagulant (LA)-1, LA-ratio, positive anti-nuclear antibody (ANA), p-anti-neutrophil cytoplasmic antibodies (ANCA), c-ANCA confirmed the diagnosis of APS. Conclusion This case report showed the feasibility of mechanical clot retrieval and stent implantation in patients with APS. Due to the elevated risk of in-stent thrombosis a prolonged therapy with glycoprotein (GP)IIb/IIIa receptor antagonists in the initial postoperative period and further anticoagulation with coumarin derivate might be needed.


Interventional Neuroradiology | 2011

treatment of vertebral Artery Origin Stenosis with a Pharos Stent device: a Single Center Experience

E. Broussalis; A.B. Kunz; G. Luthringshausen; S. Klein; M.R. Mccoy; Eugen Trinka; Monika Killer-Oberpfalzer

Atherosclerotic stenosis of vertebral artery (VA) origin exceeding 70% severity accounts for one third of all vertebrobasilar strokes. For a period of one year the results of endovascular treatment of VA stenosis with the new Pharos stent device were assessed. Twenty-two patients with symptomatic VA stenosis were treated with the Pharos stent. Clinical status and stenosis grade were documented before treatment and 24 hours, one, three and twelve months after treatment via ultrasound and magnetic resonance tomography. All procedures proved to be technically successful without the occurrence of intra-procedural complications. During the observation period of more than one year, 55% of patients were documented with a mean stenosis degree of 60%: two (10%) of these patients showed a residual stenosis after angioplasty and nine patients (45%) an in-stent restenosis, whereas only two patients were documented with a hemodynamically relevant in-stent restenosis of 80%. These two patients were retreated with balloon dilatation. None of the patients showed neurological deterioration or new abnormalities at magnetic resonance tomography examination. Neither VA occlusion nor restenosis of the contralateral VA negatively affected the clinical outcome. An in-stent restenosis was developed by more female than male patients. VA origin stenting with the Pharos stent device is an effective treatment of stenosis. The good clinical results compared to the high restenosis rates have to be examined in further studies. Pin particular, it has to be determined whether the Pharos stent allows the vessel time for collateralization, whether double antiplatelet treatment prevents recurrent cerebrovascular events or whether merely the low restenosis degree is causative for the clinical outcome.


Journal of NeuroInterventional Surgery | 2018

Surgical technique for venous patch aneurysms with no neck in a rabbit model

Kilian Greim-Kuczewski; Alejandro Berenstein; Sebastian Kis; Anna Hauser; Monika Killer-Oberpfalzer

Background Animal experimental studies are crucial for the development of endovascular devices and embolization techniques for intracranial aneurysms. The aim of the study was to describe the surgical creation technique for an aneurysm with a dilated shape and no definable aneurysm neck. The model should be reproducible in size and shape and stay patent over a long period of time. It should constitute a challenge to endovascular therapy and provide a valuable testing environment for new endovascular devices and techniques. Methods Surgical creation of 30 no-neck aneurysms was attempted in 15 New Zealand White rabbits using a segment of jugular vein, which was transected, longitudinally opened and sutured to the anterior aspect of the common carotid artery. The first 14 aneurysms were used to develop the technique. Once the technique was mastered and the procedure was standardized, 16 consecutive aneurysms were created. For these aneurysms, digital subtraction angiography was employed after a mean of 120 days to confirm size and patency. All aneurysms were evaluated for patency. Results Overall aneurysm patency was 93%. Three complications occurred, two of which were related to the vascular anastomosis. Angiographic follow-up showed a median (SD) aneurysm base and height of 6.7 (0.76) mm and 3.2 (0.85) mm), respectively. Conclusions This technique allows creation of aneurysms without a neck which are reproducible in size and shape, and which remain patent. The model contributes to the list of aneurysm models fit for evaluation of embolization devices and techniques. It is particularly useful in exploring treatment options for wide-neck aneurysms and aneurysms which presently do not qualify for conventional coiling.


Journal of stroke | 2018

Higher Blood Pressure during Endovascular Thrombectomy in Anterior Circulation Stroke Is Associated with Better Outcomes

Slaven Pikija; Vladimir Trkulja; Christian Ramesmayer; Johannes Sebastian Mutzenbach; Monika Killer-Oberpfalzer; Constantin Hecker; Nele Bubel; Michael Ulrich Füssel; Johann Sellner

Background and Purpose Reports investigating the relationship between in-procedure blood pressure (BP) and outcomes in patients undergoing endovascular thrombectomy (EVT) due to anterior circulation stroke are sparse and contradictory. Methods Consecutive EVT-treated adults (modern stent retrievers, BP managed in line with the recommendations, general anesthesia, invasive BP measurements) were evaluated for associations of the rate of in-procedure systolic BP (SBP) and mean arterial pressure (MAP) excursions to >120%/<80% of the reference values (serial measurements at anesthesia induction) and of the reference BP/weighted in-procedure mean BP with post-procedure imaging outcomes (ischemic lesion volume [ILV], hemorrhages) and 3-month functional outcome (modified Rankin Scale [mRS], score 0 to 2 vs. 3 to 6). Results Overall 164 patients (70.7% pharmacological reperfusion, 80.5% with good collaterals, 73.8% with successful reperfusion) were evaluated for ILV (range, 0 to 581 cm3) and hemorrhages (incidence 17.7%). Higher rate of in-procedure SBP/MAP excursions to >120% was independently associated with lower ILV, while higher in-procedure mean SBP/MAP was associated with lower odds of hemorrhages. mRS 0-2 was achieved in 75/155 (48.4%) evaluated patients (nine had missing mRS data). Higher rate of SBP/MAP excursions to >120% and higher reference SBP/MAP were independently associated with higher odds of mRS 0-2, while higher ILV was associated with lower odds of mRS 0-2. Rate of SBP/MAP excursions to <80% was not associated with any outcome. Conclusions In the EVT-treated patients with BP managed within the recommended limits, a better functional outcome might be achieved by targeting in-procedure BP that exceeds the preprocedure values by more than 20%.


Journal of NeuroInterventional Surgery | 2018

The Casper Stent System for carotid artery stenosis

Sebastian Mutzenbach; Katharina Millesi; Cornelia Roesler; Erasmia Broussalis; Slaven Pikija; Johann Sellner; Lukas Machegger; Christoph J. Griessenauer; Monika Killer-Oberpfalzer

Purpose To report the results of a retrospective analysis of prospectively collected data evaluating the safety and efficacy of a double layer stent engineered for carotid artery occlusive disease. Methods Between January 2014 and February 2017, 138 patients (25.4% women; median age 71 years) underwent Casper stent implantation for carotid artery stenosis. Eligibility criteria included stenosis >70% of vessel diameter (or >50% diameter with ulceration) in symptomatic patients or asymptomatic patients with >80% stenosis at the carotid bifurcation or in the proximal internal carotid artery. For all procedures, a distal embolic protection device was used. The primary endpoint was the rate of 90 day major adverse neurological events, defined as minor stroke, major stroke, or death by independent neurological assessment. Results Stent deployment was completed successfully in all cases without documented technical failure. There were no adverse neurological events or mortalities within 90 days. One thromboembolic occlusion of a small distal branch of the anterior cerebral artery occurred during the procedure and resolved with systemic recombinant tissue plasminogen activator administration. New ischemic lesions, all clinically silent, were seen in 6.5% of patients on post-procedure cerebral MRI. Conclusion The Casper carotid stent demonstrated safety and efficacy in the treatment of carotid stenosis, with no technical failures and no adverse neurological events seen throughout the 90 day follow-up period. Its double layer structure seems to combine adequate plaque scaffolding with high vessel adaptability.


Journal of NeuroInterventional Surgery | 2018

Closure of large bore 9 F arterial puncture sites with the AngioSeal STS device in acute stroke patients after intravenous recombinant tissue plasminogen activator (rt-PA)

Hendrik Janssen; Monika Killer-Oberpfalzer; Ruediger Lange

Purpose This retrospective analysis was performed to evaluate whether large bore 9 F puncture sites can be safely closed with the 8 F AngioSeal STS device after endovascular stroke procedures in patients who did or did not receive recombinant tissue plasminogen activator (rt-PA). Methods Out of 161 consecutive endovascular stroke procedures we identified 72 patients who met the inclusion criteria, of whom 46 received rt-PA before the endovascular procedure and 26 did not. All groin complications such as major haemorrhage, failure of the device to close the puncture site, delayed haemorrhage, acute lower extremity ischaemia or necessary vascular surgery as well as infections were recorded. Results Only one patient had delayed groin haemorrhage after closure of the 9 F puncture site with the AngioSeal STS device. There was no significant difference in complications between patients with or without rt-PA treatment. Conclusion The 8 F AngioSeal STS seems to be safe and efficient to close 9 F femoral artery puncture sites, even under active rt-PA thrombolysis.


Journal of NeuroInterventional Surgery | 2018

Reduction of cerebral DWI lesion burden after carotid artery stenting using the CASPER stent system

Erasmia Broussalis; Christoph J. Griessenauer; Sebastian Mutzenbach; Slaven Pikija; Hendrik Jansen; Valdo Stevanovic; Monika Killer-Oberpfalzer

Introduction Despite various measures to protect against distal embolization during carotid artery stenting (CAS), periprocedural ischemic lesions are still encountered. Objective To evaluate the periprocedural cerebral diffusion weighted imaging (DWI) lesion burden after CASPER stent placement. Methods Patients who underwent CAS using the CASPER stent system were reviewed. Degrees of carotid stenosis and plaque configuration were determined. All patients were pretreated with dual antiplatelet agents and cerebral pre- and postprocedural MRI was obtained. All CAS procedures were performed by a single operator. Results A total of 110 patients with severe carotid artery stenosis (median degree of stenosis 80%, median length of stenosis 10 mm) were treated with CAS. Hypoechogenic or heterogeneous, mostly hypoechogenic, plaques were documented in 48.6% (52/107) of patients. Carotid ulceration was present in 15.9% (17/107). Postprocedurally, 7.3% (8/110) of patients were found to have ischemic DWI lesions. They were asymptomatic in all patients. Follow-up at 90 days was available in 88.2% (97/110) of patients with excellent functional outcome (modified Rankin Scale score 0–1) in 95.9% (93/97). Conclusion Carotid artery stenting using the new CASPER stent in combination with a distal embolic protection device is safe and results in a lower rate of periprocedural DWI lesion burden compared with reported results for historic controls.


Interventional Neuroradiology | 2018

Microsurgical clipping and endovascular treatment of middle cerebral artery aneurysms in an interdisciplinary treatment concept: Comparison of long-term results:

Christoph Schwartz; Hans-Christoph Aster; Rahman Al-Schameri; Erasmia Müller-Thies-Broussalis; Christoph J. Griessenauer; Monika Killer-Oberpfalzer

Objective Treatment of middle cerebral artery (MCA) aneurysms has been historically considered as the almost exclusive domain of microsurgical clipping. This retrospective single-center study assesses whether microsurgical clipping or endovascular treatment (i.e. coiling and/or stenting) for MCA aneurysms yielded better occlusion rates and clinical outcome. Methods We identified patients with a minimum clinical follow-up of 12 months who had undergone MCA aneurysm repair either by clipping or by endovascular treatment between 2005 and 2015. Aneurysm occlusion rates were assessed by the Raymond-Roy Occlusion Classification (RROC) and patients’ clinical outcome was measured by the modified Rankin Scale (mRS). All patients had been treated in an interdisciplinary treatment concept at a large neurovascular center; both treatment modalities were available at all times. Results Ninety-two eligible patients with MCA aneurysms, of whom 21.7% patients were treated for subarachnoid hemorrhages, were included; 38 patients underwent endovascular therapy and 54 clipping. The median age at treatment was 53.5 years (range, 25–79 years) and the median clinical follow-up was 98.5 months (range, 18–213 months). Occlusion rates were significantly higher in the clipping cohort (RROC = 1: 96.3% vs 78.9%; p = 0.04), long-term clinical outcome was better in the endovascular treatment cohort (mRS ≤ 1: 100.0% vs 90.8%; p < 0.01). Permanent treatment-associated morbidity was seen more commonly in the clipping cohort (9.3% vs 0.0%). Conclusions Both treatment modalities are associated with excellent clinical and radiological outcome if applied within an interdisciplinary treatment concept. Endovascular aneurysm repair appears to be an attractive treatment alternative compared to clipping with low complication rates for well-selected patients.

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Christoph J. Griessenauer

Beth Israel Deaconess Medical Center

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