48 research outputs found

    Untersuchung zur Anwendbarkeit der Argon-Plasma-Koagulation (APC) in einem Modellversuch fĂŒr neurochirurgische Operationen

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    Die Argon-Plasma-Koagulation (APC) wird heutzutage in vielen chirurgischen Disziplinen und deren operativen Indikationen angewendet. In der Neurochirurgie wurde jedoch bisher von einer Anwendung abgesehen, da die Datenlage zur Reaktion des Nervengewebes auf diese Art der monopolaren Koagulation noch unklar ist. FĂŒr die genaue Evaluation der Art und Ausdehnung des Gewebeschadens wurde ein Tiermodell mit einem standardisierten Versuchsaufbau etabliert, um die Auswirkungen von Helium(Argon)-Plasma-Koagulation auf das Rattenhirn zu untersuchen. Die Gewebereaktionen wurden mit konventionellen und immunhistologischen FĂ€rbemethoden dokumentiert und untersucht. Weiterhin wurde ein zeitabhĂ€ngiges Profil der Umbauprozesse erstellt, welches sich ĂŒber eine bis sechs Wochen nach der Operation erstreckte. Die Gewebsreaktion stellte sich als eine Abgrenzung von klar demarkierten konzentrischen Zonen dar. Die Organisation des Gewebeschadens fand sowohl an den RĂ€ndern als auch im Zentrum der LĂ€sion statt. Die Schichten der LĂ€sion nehmen durch unterschiedliche Mechanismen an der Reparatur des Gewebeschadens teil; die weitere Beobachtung dieser Schichten kann daher zum besseren VerstĂ€ndnis der OrganisationsvorgĂ€nge fĂŒhren. Diese Studie hat gezeigt, dass man durch H(A)PC eine scharf abgrenzbare und reproduzierbare LĂ€sion an Rattenhirngewebe generieren kann. Die Methode erwies sich wie in anderen chirurgischen Indikationen als minimal traumatisch. Daher ist die klinische Anwendung dieser Methode vielversprechend. Außerdem sind die H(A)PC-LĂ€sionen sehr gut geeignet, um die Morphologie frĂŒher und spĂ€ter reparativer Reaktionen neuronaler Gewebe zu studieren

    Untersuchung zur Anwendbarkeit der Argon-Plasma-Koagulation (APC) in einem Modellversuch fĂŒr neurochirurgische Operationen

    Get PDF
    Die Argon-Plasma-Koagulation (APC) wird heutzutage in vielen chirurgischen Disziplinen und deren operativen Indikationen angewendet. In der Neurochirurgie wurde jedoch bisher von einer Anwendung abgesehen, da die Datenlage zur Reaktion des Nervengewebes auf diese Art der monopolaren Koagulation noch unklar ist. FĂŒr die genaue Evaluation der Art und Ausdehnung des Gewebeschadens wurde ein Tiermodell mit einem standardisierten Versuchsaufbau etabliert, um die Auswirkungen von Helium(Argon)-Plasma-Koagulation auf das Rattenhirn zu untersuchen. Die Gewebereaktionen wurden mit konventionellen und immunhistologischen FĂ€rbemethoden dokumentiert und untersucht. Weiterhin wurde ein zeitabhĂ€ngiges Profil der Umbauprozesse erstellt, welches sich ĂŒber eine bis sechs Wochen nach der Operation erstreckte. Die Gewebsreaktion stellte sich als eine Abgrenzung von klar demarkierten konzentrischen Zonen dar. Die Organisation des Gewebeschadens fand sowohl an den RĂ€ndern als auch im Zentrum der LĂ€sion statt. Die Schichten der LĂ€sion nehmen durch unterschiedliche Mechanismen an der Reparatur des Gewebeschadens teil; die weitere Beobachtung dieser Schichten kann daher zum besseren VerstĂ€ndnis der OrganisationsvorgĂ€nge fĂŒhren. Diese Studie hat gezeigt, dass man durch H(A)PC eine scharf abgrenzbare und reproduzierbare LĂ€sion an Rattenhirngewebe generieren kann. Die Methode erwies sich wie in anderen chirurgischen Indikationen als minimal traumatisch. Daher ist die klinische Anwendung dieser Methode vielversprechend. Außerdem sind die H(A)PC-LĂ€sionen sehr gut geeignet, um die Morphologie frĂŒher und spĂ€ter reparativer Reaktionen neuronaler Gewebe zu studieren

    Do-It-Yourself Preoperative High-Resolution Ultrasound-Guided Flap Design of the Superficial Circumflex Iliac Artery Perforator Flap (SCIP)

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    The superficial circumflex iliac artery perforator (SCIP) flap is a well-documented, thin, free tissue flap with a minimal donor site morbidity, and has the potential to become the new method for resurfacing moderate-size skin defects. The aim of this study is to describe an easy, reliable, systematic, and standardized approach for preoperative SCIP flap design and perforator characterization, using color-coded duplex sonography (CCDS). A list of customized settings and a straightforward algorithm are presented, which are easily applied by an operator with minimal experience. Specific settings for SCIP flap perforator evaluation were investigated and tested on 12 patients. Deep and superficial superficial circumflex iliac artery (SCIA) branches, along with their corresponding perforators and cutaneous veins, were marked individually with a permanent marker and the anatomy was verified intraoperatively. From this, a simplified procedure for preoperative flap design of the SCIP flap was developed. Branches could be localized and evaluated in all patients. A preoperative structured procedure for ultrasonically guided flap design of the SCIP flap is described. A 100% correlation between the number and emergence points of the branches detected by preoperative CCDS mapping and the intraoperative anatomy was found

    Using High-Resolution Ultrasound to Assess Post-Facial Paralysis Synkinesis—Machine Settings and Technical Aspects for Facial Surgeons

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    Background: Synkinesis of the facial musculature is a detrimental sequalae in post-paralytic facial palsy (PPFP) patients. Detailed knowledge on the technical requirements and device properties in a high-resolution ultrasound (HRUS) examination is mandatory for a reliable facial muscle assessment in PPFP patients. We therefore aimed to outline the key steps in a HRUS examination and extract an optimized workflow schema. Methods: From December 2020 to April 2021, 20 patients with unilateral synkinesis underwent HRUS. All HRUS examinations were performed by the first author using US devices with linear multifrequency transducers of 4–18 MHz, including a LOGIQ E9 and a LOGIQ S7 XDclear (GE Healthcare; Milwaukee, WI, USA), as well as Philips Affinity 50G (Philips Health Systems; Eindhoven, the Netherlands). Results: Higher-frequency and multifrequency linear probes ≄15 MHz provided superior imaging qualities. The selection of the preset program Small Parts, Breast or Thyroid was linked with a more detailed contrast of the imaging morphology of facial tissue layers. Frequency (Frq) = 15 MHz, Gain (Gn) = 25–35 db, Depth (D) = 1–1.5 cm, and Focus (F) = 0.5 cm enhanced the image quality and assessability. Conclusions: An optimized HRUS examination protocol for quantitative and qualitative facial muscle assessments was proposed

    Feasibility study of preoperative microvessel evaluation and characterization in perforator flaps using various modes of color-coded duplex sonography (CCDS)

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    Background Color-coded duplex sonography (CCDS) is useful for perforator flap design showing the highest sensitivity in identifying microvessels. This prospective study evaluates the feasibility of different ultrasound (US) modes applied by the microsurgeon in daily practice suggesting quantifiable reference values. Methods Twenty-four patients aged between 17 and 68 years (mean 43.3 +/- 14.2 years) with 18 anterolateral thigh (ALT) and 6 superficial circumflex iliac artery (SCIP) flaps were included. Indications were traumatic (n= 12), infectious (n= 6), ischemic (n= 4), or tumor-associated defects (n= 2). Different US modes were evaluated regarding applicability using multifrequency linear probes (5-15 MHz). Vessels diameter, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were measured. Preoperative results were correlated to intraoperative findings. Results In the examined patient group with 24 perforator flaps a 100% correlation was seen when comparing perforators detected with CCDS/PD with intraoperative findings using optimized US settings. Sensitivity, PPV, and accuracy of CCDS were 100% respectively. Mean PSV of 16.99 +/- 6.07 cm/s, mean EDV of 5.01 +/- 1.84 cm/s and RI of 0.7 +/- 0.07 were measured in microvessels (PW-mode). CCDS proved to be superior compared to PD in correct diameter assessment showing a mean diameter of 1.65 +/- 0.45 mm, compared to PD-mode 1.31 +/- 0.24 mm. Mean PSV and EDV were higher in ALT than in SCIP flaps, RI was slightly higher in SCIP flaps (p > .05). There were no significant differences in size of different flaps' perforators (p > .05). Conclusion CCDS represents a highly valuable tool in the daily practice of free flap reconstructions using optimized low flow US settings and multifrequency linear probes

    NAM—help or burden? Intercultural evaluation of parental stress caused by nasoalveolar molding: a retrospective multi-center study

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    Objectives Nasoalveolar molding (NAM) was developed to facilitate easier treatment and better outcomes for cleft lip and palate (CLP) patients. The aim of this study was to investigate the parental burden and possible intercultural differences of this treatment modality, which is often argued to burden parents to an extraordinary amount. Materials and methods Standardized questionnaires (available in English, Mandarin, and German) with 15 non-specific and 14 NAM-specific items to be retrospectively answered by Likert scales by parents of unilateral CLP patients with completed NAM treatment. Results The parents of 117 patients from two treatment centers in Taiwan and Germany were included. A very high level of overall satisfaction was found in both countries with significant intercultural differences in prenatal parent information, feeding problems, dealing with 3rd party’s perception, and experienced personal effort. Conclusion NAM is an effective treatment tool for children’s CLP deformities and their caregivers in overcoming the feeling of helplessness. Intercultural differences may be due to infrastructural reasons, cultural attitudes and habits, or different public medical education. Clinical relevance In addition to facilitating easier surgical treatment, NAM can be seen as a powerful coping strategy for parents dealing with a CLP deformity of their child and does not seem to burden them extraordinarily

    Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival

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    Extent: 14 p.The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K), promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML) cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3) and granulocyte macrophage colony stimulating factor (GM-CSF) receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting such pathways in cancer.Daniel Thomas, Jason A. Powell, Benjamin D. Green, Emma F. Barry, Yuefang Ma, Joanna Woodcock, Stephen Fitter, Andrew C.W. Zannettino, Stuart M. Pitson, Timothy P. Hughes, Angel F. Lopez, Peter R. Shepherd, Andrew H. Wei, Paul G. Ekert and Mark A. Guthridg

    Complications following orthognathic surgery for patients with cleft lip/palate: A systematic review

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    The purpose of this systematic review is to update the available data for complications following orthognathic surgery in cleft lip and/or palate patients. Methods: Three electronic databases (Medline, Embase, and Cochrane) were searched for publications from 1990 to 2014. Results: A total of 26 articles were selected including 1003 patients (male: 391, female: 353, 259: not mentioned) who underwent maxillary osteotomies for cleft lip/palate. Mean age at surgery was 19.3 years (range: 8.5–60 years). Overall perioperative complications were reported in 126 cases (12.76%). The most common complication was closure failure of pre-existing palatal fistula (28.57%), followed by velopharyngeal impairment (16.79%), closure failure of pre-existing alveolar fistula (10.74%), gingival recession (4.55%), and failure of premaxilla stabilization in bilateral cases (4.55%). Severe vascular complications included one arteriovenous fistula (0.10%), one maxillary aneurysm (0.10%), and one cavernous sinus thrombosis (0.10%). Mean horizontal relapse rate was 17.9% (range: −20.0% to 37.2%), and mean vertical relapse rate was 35.4% (range: −25.9% to 162.5%). Reoperation rate was 12.2% (range: 0.0–64.0%). Prospective studies or randomized trials were rare. Conclusion: To obtain a dataset with higher evidence, a prospective multicenter study should be conducted with clearly defined criteria for each complication

    3D printing in orthognathic surgery − A literature review

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    With the recent advances in three-dimensional (3D) imaging, computer-assisted surgical planning and simulation are now regularly used for analysis of craniofacial structures and improved prediction of surgical outcomes in orthognathic surgery. A variety of patient-specific surgical guides and devices have been designed and manufactured using 3D printing technology, which rapidly gained widespread popularity to improve the outcomes. The article presents an overview of 3D printing technology for state-of-the-art application in orthognathic surgery and discusses the impacts on treatment feasibility and patient outcome. The current available literature regarding the use of 3D printing methods in orthognathic surgery including 3D computer-aided design/computer-aided manufacturing, rapid prototyping, additive manufacturing, 3D printing, 3D printed models, surgical occlusal splints, custom-made guides, templates and fixation plates is reviewed. A Medline, PubMed, ProQuest and ScienceDirect search was performed to find relevant articles over the past 10 years. A total of 318 articles were found, out of which 69 were publications addressing the topic of this study. An additional 9 hand-searched articles were added. From the review, we can conclude that the use of 3D printing methods in orthognathic surgery provide the benefit of optimal functional and aesthetic results, patient satisfaction, and precise translation of the treatment plan. Keywords: Orthognathic surgery, 3D printing, Computer-aided design, Computer-aided manufacturing, Rapid prototyping, Additive manufacturin
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