Freimann, Florian Baptist

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Neurological Surgery Part A Central European Neurosurgery"],["dc.bibliographiccitation.volume","77"],["dc.contributor.author","Freimann, Florian Baptist"],["dc.contributor.author","Thomale, Ulrich-Wilhelm"],["dc.date.accessioned","2018-11-07T10:21:20Z"],["dc.date.available","2018-11-07T10:21:20Z"],["dc.date.issued","2016"],["dc.format.extent","1"],["dc.identifier.doi","10.1055/s-0035-1566300"],["dc.identifier.isi","000368522900001"],["dc.identifier.pmid","26761508"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42063"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Thieme Medical Publ Inc"],["dc.relation.issn","2193-6323"],["dc.relation.issn","2193-6315"],["dc.title","Obituary Christian Sprung In Memoriam"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2191"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Acta Neurochirurgica"],["dc.bibliographiccitation.lastpage","2199"],["dc.bibliographiccitation.volume","156"],["dc.contributor.author","Freimann, Florian Baptist"],["dc.contributor.author","Kimura, Takaoki"],["dc.contributor.author","Stockhammer, Florian"],["dc.contributor.author","Schulz, Matthias"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Thomale, Ulrich-Wilhelm"],["dc.date.accessioned","2018-11-07T09:33:12Z"],["dc.date.available","2018-11-07T09:33:12Z"],["dc.date.issued","2014"],["dc.description.abstract","Anti-siphon devices (ASDs) of various working principles were developed to overcome overdrainage-related complications associated with ventriculoperitoneal shunting. We aimed to provide comparative data on the pressure and flow characteristics of six different types of ASDs (gravity-assisted, membrane-controlled, and flow-regulated) in order to achieve a better understanding of these devices and their potential clinical application. We analyzed three gravity-dependent ASDs (ShuntAssistant [SA], Miethke; Gravity Compensating Accessory [GCA], Integra; SiphonX [SX], Sophysa), two membrane-controlled ASDs (Anti-Siphon Device [IASD], Integra; Delta Chamber [DC], Medtronic), and one flow-regulated ASD (SiphonGuard [SG], Codman). Defined pressure conditions within a simulated shunt system were generated (differential pressure 10-80 cmH(2)O), and the specific flow and pressure characteristics were measured. In addition, the gravity-dependent ASDs were measured in defined spatial positions (0-90A degrees). The flow characteristics of the three gravity-assisted ASDs were largely dependent upon differential pressure and on their spatial position. All three devices were able to reduce the siphoning effect, but each to a different extent (flow at inflow pressure: 10 cmH(2)O, siphoning -20 cmH(2)O at 0A degrees/90A degrees: SA, 7.1 A +/- 1.2 /2.3 A +/- 0.5 ml/min; GCA, 10.5 A +/- 0.8/3.4 A +/- 0.4 ml/min; SX, 9.5 A +/- 1.2 /4.7 A +/- 1.9 ml/min, compared to control, 11.1 A +/- 0.4 ml/min [ p < 0.05]). The flow characteristics of the remaining ASDs were primarily dependent upon the inflow pressure effect (flow at 10 cmH2O, siphoning 0 cmH(2)O/ siphoning -20cmH(2)O: DC, 2.6 A +/- 0.1/ 4 A +/- 0.3 ml/min; IASD, 2.5 A +/- 0.2/ 0.8 A +/- 0.4 ml/min; SG, 0.8 A +/- 0.2 / 0.2 A +/- 0.1 ml/min [ p < 0.05 vs. control, respectively]). The tested ASDs were able to control the siphoning effect within a simulated shunt system to differing degrees. Future comparative trials are needed to determine the type of device that is superior for clinical application."],["dc.identifier.doi","10.1007/s00701-014-2201-y"],["dc.identifier.isi","000343884400023"],["dc.identifier.pmid","25123252"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31916"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","Wien"],["dc.relation.issn","0942-0940"],["dc.relation.issn","0001-6268"],["dc.title","In vitro performance and principles of anti-siphoning devices"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Neurosurgical Review"],["dc.contributor.author","Bettag, Christoph"],["dc.contributor.author","von der Brelie, Christian"],["dc.contributor.author","Freimann, Florian Baptist"],["dc.contributor.author","Thomale, Ulrich-Wilhelm"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Fiss, Ingo"],["dc.date.accessioned","2021-06-01T10:49:17Z"],["dc.date.available","2021-06-01T10:49:17Z"],["dc.date.issued","2021"],["dc.description.abstract","Abstract Diagnosis of symptomatic valve malfunction in hydrocephalic patients treated with VP-Shunt (VPS) might be difficult. Clinical symptoms such as headache or nausea are nonspecific, hence cerebrospinal fluid (CSF) over- or underdrainage can only be suspected but not proven. Knowledge concerning valve malfunction is still limited. We aim to provide data on the flow characteristics of explanted shunt valves in patients with suspected valve malfunction. An in vitro shunt laboratory setup was used to analyze the explanted valves under conditions similar to those in an implanted VPS. The differential pressure (DP) of the valve was adjusted stepwise to 20, 10, 6, and 4 cmH 2 O. The flow rate of the explanted and the regular flow rate of an identical reference valve were evaluated at the respective DPs. Twelve valves of different types (Codman CertasPlus valve n  = 3, Miethke Shuntassistant valve n  = 4, Codman Hakim programmable valve n  = 3, DP component of Miethke proGAV 2.0 valve n  = 2) from eight hydrocephalic patients (four male), in whom valve malfunction was assumed between 2016 and 2017, were replaced with a new valve. Four patients suffered from idiopathic normal pressure (iNPH), three patients from malresorptive and one patient from obstructive hydrocephalus. Post-hoc analysis revealed a significant difference ( p  < 0.001) of the flow rate between each explanted valve and their corresponding reference valve, at each DP. In all patients, significant alterations of flow rates were demonstrated, verifying a valve malfunction, which could not be objectified by the diagnostic tools used in the clinical routine. In cases with obscure clinical VPS insufficiency, valve deficiency should be considered."],["dc.identifier.doi","10.1007/s10143-021-01564-8"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/86232"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.relation.eissn","1437-2320"],["dc.relation.issn","0344-5607"],["dc.title","In vitro testing of explanted shunt valves in hydrocephalic patients with suspected valve malfunction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]