Im Rahmen der vorliegenden retrospektiven Studie wurden die Fälle von 418 Patienten mit distaler Radiusfraktur untersucht. Die Patienten waren 0-16 Jahre alt und wurden in den Jahren 2006-2017 im Uniklinikum Würzburg behandelt. Aufgrund der hohen Fallzahl und des langen Beobachtungszeitraumes war ein umfassender Blick auf Epidemiologie, Therapiestrategien, Therapieergebnisse und deren Entwicklung während des untersuchten Zeitraums möglich. / The study analyzed 418 cases of children with distal radius fractures. The children were between 0-16 years old and treated during the years 2006-2017 at the Uniklinikum Würzburg. The goal was an objective examination of etiology, strategies of treatment, outcome and their development in the examined time period.

Hintergrund: Distale Radiusfrakturen sind eine der häufigsten Frakturformen und werden zumeist mit einer palmaren Platte versorgt. Ziel dieser Arbeit war es die Behandlungseffizienz und Komplikationsraten der palmaren winkelstabilen Aptus 2,5 mm Rahmenplatte von MedArtis zu untersuchen und mit publizierten Daten anderer Behandlungsmethoden zu vergleichen. Patienten und Methoden: In dieser Studie waren 153 Patienten eingeschlossen mit einem follow-up von >90% in der klinischen Nachuntersuchung. Es erfolgte eine Anamnese über den Unfallhergang und postoperative Komplikationen, eine Inspektion, Palpation sowie Messung der Bewegungsausmaße und Kraft, eine Einordnung in den Gartland & Werley Score, eine Erhebung des subjektiven Wohlempfindens mittels DASH-Score, eine Bewertung prä- und postoperativer Röntgenbilder sowie ein Literaturvergleich. Ergebnis: Bei der Operation mit der Aptus 2,5 mm palmaren winkelstabilen Rahmenplatte von MedArtis handelt es sich um ein sicheres Verfahren in der Behandlung dislozierten distalen Radiusfrakturen mit exzellenten funktionellen Ergebnissen. Die palmare Rahmenplatte kann bei guter operativer Technik als M. Pronator-quadratus-sparendes Standardimplantat empfohlen werden. / Background: Distal radius fractures are one of the most common types of fractures and are usually treated with a palmar plate. The aim of this study was to investigate the treatment efficacy and complication rates of the MedArtis palmar fixed angle 2.5 mm plate and to compare it with published data from other treatment methods. Patients and methods: In this study, 153 patients were included with a follow-up of > 90% in the clinical follow-up. Beside an anamnese about the accident itself and postoperative complications, an inspection, palpation and measurement of movement and strength, a classification in the Gartland & Werley Score, a survey of subjective well-being using DASH score, a rating of pre- and postoperative X-rays and a literature comparison was done. Results: The Aptus 2.5 mm palmar fixed angle plate from MedArtis is a secure procedure for treating dislocated distal radius fractures with excellent functional results. The palmar plate can be recommended as a M. Pronator quadratus-sparing standard implant.

Ziel/Hintergrund: Die Behandlung der distalen Radiusfraktur machte mit der Zeit eine zunehmende Entwicklung, sodass heute eine Vielzahl von verschiedenen Behandlungsverfahren beschrieben wurden. Dabei befasst sich die vorliegende retrospektive Studie vor allem mit der objektiven, subjektiven, funktionellen und radiologischen Bewertung des Behandlungsergebnisses beim Einsatz der palmaren winkelstabilen Aptus 2,5 mm Rahmenplatte der Firma Medartis. Patienten und Methoden: Es wurden 87 Patienten mit 88 distalen Radiusfrakturen im untersuchten Zeitraum vom 01.01.2009 bis 31.12.2011 mit der palmaren winkelstabilen Aptus 2,5mm Rahmenplatte der Firma Medartis in die Studie aufgenommen. Alle Frakturen wurden nach AO klassifiziert. Während der Nachuntersuchung wurde die Patientenanamnese, der Unfallhergang, das funktionelle Outcome im Sinne der Kraft und der Bewegung am Handgelenk und die radiologischen Parameter erhoben. Eine Einordnung in den Gartland und Werley Score, eine Erhebung des subjektiven Wohlempfindens mittels DASH-Score sowie die Einteilung in die Soong Klassifikation erfolgte ebenfalls. Ergebnis: Die durchschnittliche Follow Up Zeit lag bei 57±10,9 Monaten. Das Durchschnittsalter der Patienten lag bei 58±17,2 Jahren. Es wurden zehn A2, 21 A3, eine B1, zwei B2, eine B3, sieben C1, 18 C2 und 28 C3 Frakturen erfasst. Das Ergebnis der radiologischen Untersuchung zeigt, dass alle präoperativ gemessenen Parameter höchstsignifikante Unterschiede zu postoperativen Verhältnissen aufwiesen. Nach radiologischer Sicht zeigen 68% des Patientenkollektivs ein einwandfreies Ergebnis mit einem Radiusbasiswinkel von 23°, Dorso-Palmaren Kippwinkel von 3°, einer Ulnar Varianz von +1 mm und einer Radiushöhe von 11 mm. Die Patienten erreichten 98% des Bewegungsausmaß verglichen zu ihrer gesunden Gegenseite. Zusammenfassend konnte bei 79% des Patientenkollektivs ein exzellentes bis gutes Kraftergebnis zur intakten Gegenseite ermittelt werden. Mit einem durchschnittlichen Punktewert von 10 erreichten die Patienten ein exzellentes bis gutes Ergebnis im DASH Score. Auch beim Gartland und Werley Score zeigten sich mit einem durchschnittlichen Punktewert von 1, 85% mit einem exzellenten und 15% mit einem guten Ergebnis. Insgesamt wurden 43 Platten in Klasse 0, 37 Implantate in Klasse 1 und lediglich 2 Platten in Klasse 2 nach Soong klassifiziert. Insgesamt ließ sich bei einem Patienten eine frühe Infektion erkennen, welches sich mit oralen Antibiotika gut behandeln ließ. Drei weitere Patienten wiesen eine intraartikuläre Schraubenlage auf. Schlussfolgerung: Bei der Aptus 2,5 mm palmaren winkelstabilen Rahmenplatte von MedArtis handelt es sich um ein sicheres Verfahren in der Behandlung distaler Radiusfrakturen mit sehr guten objektiven, subjektiven, radiologischen und funktionellen Ergebnissen. Die palmare Rahmenplatte kann somit als Standardimplantat empfohlen werden. / Purpose/Background: Distal radius fractures are difficult to manage and so various treatment modalities have been described. This retrospective study presents our experience by using a volar variable-angle locking plate (Aptus 2.5 mm frame plate by Medartis) to evaluate the objective, subjective, functional and radiological outcomes. Patients and Methods: We reviewed 87 patients with mit 88 distal radius fractures that were treated at our institution with volar variableangle locking plates (Aptus 2.5 mm frame plate by Medartis) during 01.01.2009 and 31.12.2011. The fractures were classified according to AO. The follow-up examination included the study of the patient’s history, anamnese about the accident itself, the functional evaluation by measuring the range of motion at the wrist joint as well as the strength and measurment of radiographical parameters. A classification in the Gartland and Werley Score, the DASH score and Soong Classification was also done. Results: The average follow-up time was 57±10,9 months. The mean age of the examined patients was 58±17,2 years. There were ten A2, 21 A3, one B1, two B2 and one B3 fractures, seven C1,18 C2 and 28 C3 fractures. The result of the radiographical measurment shows a significant difference between the pre- and postoperativ parameters. At follow-up the average radial inclination was 23°, the palmar tilt was 3°, ulnar variance was +1 mm and the radial height was 11 mm. 98% of the patients reached an unrestricted wrist motion to their uninjured contralateral side. By testing the strength 79% of the patients reached an good to excellent result to their contralateral side. Patients regained excellent function as represented in an average DASH score of 10 points. According to Gartland and Werley, excellent results were reported in 85% cases, while good results were present in 15% cases. The mean Gartland and Werley score of 1 point was reached. 43 plates were Soong grade 0, 37 plates were Soong grade 1 and 2 plates were Soong grade 2. There was one patient with an early infection that responded to oral antibiotics. And three cases of an intraarticular screw placement. Conclusions: The use of Aptus 2.5 mm frame plate by Medartis in the treatment of distal radius fractures is associated with very good objective, subjective, radiographical and functional outcomes with minimal complications. The palmar plate can be recommended as a standard implant.

Hintergrund: Distale Radiusfrakturen sind eine der häufigsten Frakturformen und stellen den Operateur nicht selten vor eine große Herausforderung. In unserer Studie bewerten wir die Rolle der prä- und postoperativen CT-Untersuchung in Bezug auf das postoperative Outcome und prüfen erneut die Indikationsstellung. Patienten und Methoden: In dieser Studie waren 163 Patienten mit insgesamt 173 Frakturen eingeschlossen. Es wurden zwei Gruppen gebildet ohne (Gruppe 1, 78 Patienten) und mit (Gruppe 2, 85 Patienten) postoperativer CT. Die postoperativen Röntgenbilder der Gruppe 2 wurden in 3 Kategorien geteilt, welche mit der postoperativen CT-Untersuchung verglichen wurden. Ergebnis: Es zeigte sich eine hohe Korrelation zwischen den beiden Untersuchungsmethoden bezüglich der Revisionsrate. Schlussfolgerung: Die postoperative CT-Untersuchung kann in vielen Fällen durch eine einfache Röntgenaufnahme vermieden werden. Um den Operateur bei der Entscheidung für oder gegen eine postoperative CT-Untersuchung zu unterstützen erstellten wir einen einfachen Algorithmus, um die Strahlenbelastung der Patienten zu minimieren ohne das postoperative Outcome zu verschlechtern. / Background: Distal radius fractures are one of the most common fractures and often pose a big challenge to the surgeon. In our study we assess the role of the pre-and postoperative CT scan relating to the postoperative outcome and try to revalue the indications of postoperative CT scan. Patients and Methods: 163 patients with 173 intraarticular distal radius fractures were included in this study. They were split in two groups without (group 1, 78 patients) and with (group 2, 85 patients) postoperative CT scan. The postoperative radiographs of group 2 were split in 3 categories and compared to the postoperative CT scan. Results: The results of this correlation showed a high statistical significance regarding the revision rate. Conclusions: A normal x-ray photograph can often avoid a postoperative CT scan. To support the surgeon`s decision for or against a postoperative CT scan we worked out a simple algorithm with the intention to minimize the radiation exposure for the patients without limiting the postoperative outcome.

Die vorliegende Arbeit befasst sich mit therapierelevanten Faktoren bei distalen Radiusfrakturen. Auf der Grundlage der nach AO klassifizierten, distalen Radiusfrakturen werden sowohl verletzungsbedingte, als auch therapiebedingte Einflußfaktoren hinsichtlich des klinisch-radiologischen Ergebnisses untersucht. Es erfolgt die Darstellung der Komplikationshäufigkeit bei operativ und konservativ versorgten distalen Radiusfrakturen. Diese wird in Zusammenhang mit unfall-und patientenbezogenen Faktoren, Begleitverletzungen und therapiebezogenen Einflußfaktoren untersucht und am klinisch-radiologischen Ergebnis gemessen. Zur Objektivierung der klinisch-radiologischen Nachuntersuchung dienen der DASH-Score, der Gartland und Werley-Score (modifiziert nach Sarmiento) und der Stewart Score.

Die vorliegende Arbeit befasst sich mit therapierelevanten Faktoren bei distalen Radiusfrakturen. Auf der Grundlage der nach AO klassifizierten, distalen Radiusfrakturen werden sowohl verletzungsbedingte, als auch therapiebedingte Einflußfaktoren hinsichtlich des klinisch-radiologischen Ergebnisses untersucht. Es erfolgt die Darstellung der Komplikationshäufigkeit bei operativ und konservativ versorgten distalen Radiusfrakturen. Diese wird in Zusammenhang mit unfall-und patientenbezogenen Faktoren, Begleitverletzungen und therapiebezogenen Einflußfaktoren untersucht und am klinisch-radiologischen Ergebnis gemessen. Zur Objektivierung der klinisch-radiologischen Nachuntersuchung dienen der DASH-Score, der Gartland und Werley-Score (modifiziert nach Sarmiento) und der Stewart Score.

No description available.

La masse corporelle et la direction des charges sont des facteurs qui peuvent modifier la morphologie des surfaces articulaires qui sont généralement orientées et de taille suffisante pour résister aux charges chroniques. Chez les hominoïdes, les forces de tension et compression, générées par la locomotion, sont transmises à travers l’articulation du coude. Ces espèces ont une morphologie similaire de l’extrémité distale de l’humérus, mais qui présente certaines différences selon la taille des individus et leurs modes de locomotion. Ce projet tente de caractériser plus exhaustivement cette variation en analysant la largeur des surfaces articulaires ainsi que leur position et orientation par rapport à l’axe long de la diaphyse. La prémisse de ce mémoire est que, chez les espèces plus arboricoles, la morphologie de l’articulation distale de l’humérus répond aux stress transverses générés par les puissants muscles fléchisseurs du poignet et des doigts qui traversent le coude obliquement. En revanche, les espèces plus terrestres présentent une morphologie permettant de résister aux forces axiales provenant du contact avec le sol. Des coordonnées tridimensionnelles et des mesures linéaires ont été recueillies sur un échantillon squelettique d’individus des genres Homo, Pan, Gorilla et Pongo. Les résultats obtenus révèlent que l’orientation et la position des surfaces articulaires de la trochlée correspondent aux types de locomotion, or leur taille et celle et du capitulum semblent être influencées par la taille des individus. L’hypothèse suggérant que les stress reliés aux divers modes de locomotion des hominoïdes influencent la morphologie de l’articulation distale de l’humérus est donc supportée. / In hominoids, tensile and compressive forces generated by locomotion and upper-limb use are transmitted through the elbow joint. It has been noticed that the distal humerus of hominoid is morphologically very similar across species. However, some studies have suggested that articular shape varies in relation to size and locomotor modes. This project is an attempt to characterize more thoroughly distal humeral variation in hominoids. It considers the humeral trochlea not only as a structure by itself, as it has been done before, but as an articulation that varies in orientation relative to the diaphysis. Indeed, there is evidence that articulations have a minimum size and are generally oriented to better resist habitual loads. This project tested the hypothesis that predominantly arboreal species are expected to present joints that have a size, position and orientation of articular surfaces to better resist shear loads generated by the strong finger and wrist flexor muscles crossing the elbow obliquely. Consequently, predominantly terrestrial species should present articulations shape and orientation that are better to resist axial load generated by ground reaction forces. Ten landmarks and two linear measurements were taken from a skeletal sample including specimens from the Homo, Pan, Gorilla and Pongo genus. Results show that orientation and position of humeral trochlea joint surfaces correlate with locomotor modes and that length of the articular surfaces seems to be better correlated with size. The main hypothesis suggesting that stress related to locomotion in hominoids should influence the morphology of distal humeral joints is therefore supported.

La masse corporelle et la direction des charges sont des facteurs qui peuvent modifier la morphologie des surfaces articulaires qui sont généralement orientées et de taille suffisante pour résister aux charges chroniques. Chez les hominoïdes, les forces de tension et compression, générées par la locomotion, sont transmises à travers l’articulation du coude. Ces espèces ont une morphologie similaire de l’extrémité distale de l’humérus, mais qui présente certaines différences selon la taille des individus et leurs modes de locomotion. Ce projet tente de caractériser plus exhaustivement cette variation en analysant la largeur des surfaces articulaires ainsi que leur position et orientation par rapport à l’axe long de la diaphyse. La prémisse de ce mémoire est que, chez les espèces plus arboricoles, la morphologie de l’articulation distale de l’humérus répond aux stress transverses générés par les puissants muscles fléchisseurs du poignet et des doigts qui traversent le coude obliquement. En revanche, les espèces plus terrestres présentent une morphologie permettant de résister aux forces axiales provenant du contact avec le sol. Des coordonnées tridimensionnelles et des mesures linéaires ont été recueillies sur un échantillon squelettique d’individus des genres Homo, Pan, Gorilla et Pongo. Les résultats obtenus révèlent que l’orientation et la position des surfaces articulaires de la trochlée correspondent aux types de locomotion, or leur taille et celle et du capitulum semblent être influencées par la taille des individus. L’hypothèse suggérant que les stress reliés aux divers modes de locomotion des hominoïdes influencent la morphologie de l’articulation distale de l’humérus est donc supportée. / In hominoids, tensile and compressive forces generated by locomotion and upper-limb use are transmitted through the elbow joint. It has been noticed that the distal humerus of hominoid is morphologically very similar across species. However, some studies have suggested that articular shape varies in relation to size and locomotor modes. This project is an attempt to characterize more thoroughly distal humeral variation in hominoids. It considers the humeral trochlea not only as a structure by itself, as it has been done before, but as an articulation that varies in orientation relative to the diaphysis. Indeed, there is evidence that articulations have a minimum size and are generally oriented to better resist habitual loads. This project tested the hypothesis that predominantly arboreal species are expected to present joints that have a size, position and orientation of articular surfaces to better resist shear loads generated by the strong finger and wrist flexor muscles crossing the elbow obliquely. Consequently, predominantly terrestrial species should present articulations shape and orientation that are better to resist axial load generated by ground reaction forces. Ten landmarks and two linear measurements were taken from a skeletal sample including specimens from the Homo, Pan, Gorilla and Pongo genus. Results show that orientation and position of humeral trochlea joint surfaces correlate with locomotor modes and that length of the articular surfaces seems to be better correlated with size. The main hypothesis suggesting that stress related to locomotion in hominoids should influence the morphology of distal humeral joints is therefore supported.

Background: Permanent paraplegia is a rare but feared complication of both open and endovascular thoracoabdominal aortic repair. The rate of postoperative paraplegia varies depending on the extent of open repair, from 0.9% to 4.7%, even in expert centers (Coselli et al. 2016; Etz et al. 2015). Among the currently available protective adjuncts, distal perfusion (DP) and cerebrospinal fluid (CSF) drainage are one of the most widely used ones (Etz et al. 2015). The scientific evidence of DP is based on observational clinical studies with heterogenous patients and perioperative strategies, and few experimental works with various combinations of preventive techniques analyzed simultaneously (Rose et al. 1997; Winnerkvist et al. 2002). Aim of the study: The aim of the study was to evaluate the isolated effect of DP on regional spinal cord perfusion during aortic cross-clamping, and additional deliberate CSF pressure elevation in a large animal model. Additionally, we aimed to assess DP impact on paraspinous muscle perfusion, and evaluate the efficacy of collateral network near-infrared spectroscopy (cnNIRS) as a monitoring technique during DP. Methods: The study was performed in an acute large animal model (8 juvenile female German landrace pigs) via upper left lateral thoracotomy in the 3rd intercostal space, and retroperitoneal access. Distal perfusion was performed using partial cardiopulmonary bypass (CPB) with target perfusion pressure of 60 mmHg. Arterial lines of CPB were placed into the descending thoracic and abdominal aorta, and the venous line – into the pulmonary artery. Lumbar puncture at the L3-L4 level was performed in order to perform plasma injection during CSF pressure elevation stage. Spinal cord and paraspinous muscle regional perfusion was evaluated using microspheres injections (a total of 6 colors) at four experimental time-points: on running CPB (baseline), 5 minutes after proximal aortic cross-clamping, 5 minutes after abdominal aortic cross-clamping and initiation of DP, and after 15 minutes of manually increased (tripled) CSF pressure. During the DP, proximal and distal blood flows were evaluated separately with two microsphere colors injected simultaneously via CPB arterial lines. For the analysis, the spinal cord was divided into three segments: upper (C1-T7), mid- (T8-L2) and lower (L3-S). Paraspinous muscle perfusion and oxygenation were assessed at 4 levels: mid- and lower thoracic, upper and lower lumbar levels. At the end of each experiment, the whole spinal cord and 2 cm3 samples of paraspinous muscles corresponding to the cnNIRS levels, were harvested. Results: Spinal Cord Perfusion: In the upper spinal cord, statistically significant changes of regional perfusion were observed both after DTA cross-clamping (decrease to 62% from baseline), and after distal aortic cross-clamping with initiation of DP (increase to 156% in proximal and decrease to 5% from baseline in distal flow). These were followed by a significant drop of proximal spinal cord perfusion (from 152% back to 102%, p = 0.038), and some increase of distal perfusion values (from 5% to 19%, however not reaching statistical significance) during the CSF pressure elevation stage. In the mid-spinal cord, a notable decrease of perfusion was observed after proximal aortic cross-clamping (to 27%, p = 0.025). The initiation of DP was not associated with any notable changes in proximal and distal perfusion values. Afterwards, a decrease of proximal and distal perfusion values (from 33% to 13% in proximal, and from 24% to 10% in distal perfusion) was observed during CSF pressure elevation stage. These changes were, however, not statistically significant. Lower spinal cord measurements showed, similarly to mid-segment, a decrease in perfusion after DTA cross-clamping (to 14% from baseline, p = 0.001). Initiation of DP led to normalization of proximal perfusion of the lower spinal cord (to 96% from baseline). At the same time, it was associated with extreme hyperperfusion due to distal perfusion (up to 480% from baseline). The tripling of CSF pressure resulted in decrease of both proximal (from 96% to 59%, p = 0.131) and distal (from 480% to 468%, p = 0.999) perfusion rates. Paraspinous muscle perfusion: The analysis of paraspinous muscle (i.e. collateral network) perfusion values revealed few statistically significant changes. Proximal aortic cross-clamping resulted in a decrease of paraspinous muscle perfusion (not reaching statistical significance). The least perfused were lower thoracic and upper lumbar segments. Neither initiation of DP, nor CSF pressure elevation were associated with any statistically significant changes in paraspinous muscles perfusion at any of the analyzed levels, except the lower lumbar one. Here, the distal perfusion increased from 7% to 27% from baseline during DP, and from 27% to 60% during the CSF elevation stage (p = 0.034). cnNIRS: Continuous cnNIRS monitoring did not reveal any notable changes at the mid-thoracic level. At the other three levels, the values decreased after DTA cross-clamping (p < 0.001 according to ANOVA). At the lower thoracic level, the tissue oxygenation values crossed the 70% from baseline ischemic threshold after initiation of DP. CSF pressure elevation did not have any influence on cnNIRS values at any level. Discussion: Comparison of the present experiment with the previously published studies is limited due to discrepancy in experimental sequences, analyzed segments and possible effects of other protective adjuncts used in the studies. However, in the initial phase of the experiment, the decrease of blood flow in all the spinal cord segments, was similar to the previously published works (Brattli et al. 2007; von Aspern et al. 2020). These changes were used as a second, “ischemic” baseline during the present study. Initiation of the DP led to limited or no perfusion increase of spinal cord perfusion in upper (C1-T7) and mid-spinal cord (T8-L2). And, if in the upper spinal cord this could be compensated by increased proximal flow, the mid-spinal cord was the least protected segment. At the same time, it was associated with extreme hyperperfusion (due to distal flow) of the spinal cord in the lumbar segment (L3-S), which is a known risk factor of spinal cord injury itself (Bower et al. 1989; Gallagher et al. 2019). The CSF pressure elevation resulted in further spinal cord tissue perfusion decrease, as previously reported by Haunschild et al. in experiments without aortic cross-clamping and DP (Haunschild et al. 2020). Although these changes were statistically significant only at the upper spinal cord level, they resulted in a pronounced reduction of proximal perfusion also in the other two spinal cord segments. Similarly, the decrease was observed also in distal perfusion in the mid- and lower spinal cord. Summarizing these findings, one would suggest that not only did DP (with 60 mmHg pressure) not lead to adequate protection of the mid-spinal cord during aortic cross-clamping, but it also was not able to protect it in the presence of increased CSF pressure. One also needs to point out, that although elevated CSF pressure led to some decrease of distal flow in lumbar segment, it did not eliminate the hyperperfusion of the spinal cord. In paraspinous muscle perfusion, as previously reported by von Aspern and colleagues, the perfusion reduction was more prominent in the lower thoracic and upper lumbar segments, which corresponds with the spinal cord regional perfusion results. During the next stages, almost no changes were observed in paraspinous muscles perfusion. The exclusion was the lower lumbar level, where some increase of distal perfusion was observed, however not reflecting the hyperperfusion of the spinal cord at this level. As a reflection of collateral perfusion, collateral network oxygenation monitoring using cnNIRS demonstrated limited changes. The most pronounced decrease of oxygenation was observed after aortic cross-clamping, thus following the pattern reported by von Aspern (von Aspern et al. 2020). However, at lower thoracic level, the values did cross the 70% ischemic threshold after initiation of DP, signaling ischemia. Similarly to paraspinous muscle perfusion, cnNIRS was not able to reflect the hyperperfusion of the distal spinal cord. Conclusions: The present study points out, that DP during open thoracoabdominal aortic repair should be managed with caution. It was shown that DP with stable unadjusted perfusion pressure of 60 mmHg does not provide adequate protection at the mid-thoracic level of the spinal cord and could not counteract CSF pressure elevation. At the same time, it may be associated with hyperperfusion of its distal segment. Distal perfusion, both with normal and elevated CSF pressure, did not lead to any significant changes in paraspinous muscles perfusion, except the lower lumbar segment. However, the lowest perfusion values were observed around the mid-spinal cord (the most vulnerable) area. Moreover, despite the fact that cnNIRS was able to reflect severe spinal cord ischemia, it did not reveal the spinal cord hyperperfusion. Further studies, including chronic animal experiments, are required for precise evaluation of DP in various pressure modes, and its ability to counteract the elevated CSF pressure.:Table of contents III List of abbreviations V 1 Introduction 1 1.1 Anatomy of the aorta 1 1.2 Descending thoracic and thoracoabdominal aortic pathology 2 1.3 Open surgical and endovascular treatment of thoracic and thoracoabdominal aortic pathology 4 1.4 Postoperative spinal cord injury 7 1.5 Spinal cord anatomy 9 1.6 Spinal cord blood supply: collateral network concept 10 1.7 Perioperative and adjunctive strategies to prevent spinal cord injury 12 1.8 Swine as an experimental model for spinal cord injury research 15 2 Aim of the study 16 3 Materials 17 3.1 Experimental materials 17 3.1.1 Devices 17 3.1.2 Expendable materials and instruments 18 3.1.3 Medications and chemicals 20 3.2 Laboratory materials 22 3.2.1 Devices 22 3.2.2 Expendable materials and instruments 23 3.2.3 Chemicals 25 3.3 Software 26 4 Methods 27 4.1 Experimental model 27 4.1.1 Experimental animals 27 4.1.2 Anaesthesia 28 4.1.3 Surgical approach and experimental sequence 29 4.1.4 Tissue harvesting and preparation 33 4.2 Analysis during the experiment 33 4.2.1 Microsphere measurements 33 4.2.2 Collateral network near-infrared spectroscopy 38 4.2.3 Histopathological assessment 39 4.2.4 Statistical analysis 42 5 Results 43 5.1 Vital parameters during the experiment 43 5.2 Spinal cord regional perfusion 45 5.3 Collateral network regional perfusion 50 5.4 Collateral network oxygenation 54 5.5 Relationships between regional perfusion and oxygenation values 56 5.6 Histopathological assessment 60 6 Discussion 62 6.1 Discussion of vital parameters during the experiment 64 6.2 Discussion of spinal cord regional perfusion 66 6.3 Discussion of collateral network regional perfusion 71 6.4 Discussion of collateral network oxygenation 73 6.5 Discussion of the relationships between regional perfusion and 75 oxygenation values 6.6 Discussion of histopathological results 76 6.7 Conclusions 77 6.8 Limitations of the study 78 7 Summary 81 8 References 86 9 Figure legends 103 10 Table legends 105 Acknowledgements 106 Declaration about the independent work for dissertation 107 Curriculum vitae 108