Search results for "Intraoperative"

Anwendungsm�glichkeiten der intraoperativen Sonographie

1983

Sonographie, Computertomographie, Angiographie und endoskopisch retrograde Cholangiopancreaticographie haben sich in der Allgemein- und Gefaschirurgie als wertvolle Untersuchungsmethoden etabliert. Schwierigkeiten bestehen jedoch manchmal in der Korrelation der Praoperativen Befunde mit dem intraoperativen Befund. Hier ist das Anwendungsgebiet der intraoperativen Sonographie (IOS) zu sehen. Sie bietet dem Chirurgen eine zusatzliche Information durch Darstellung von pathologischen Gefasprozessen, Kontrolle von Gefasanastomosen, intraoperative FlowMessung in Gefasen, Lokalisationsdiagnostik in parenchymatosen Organen. Die intraoperative Sonographie ist somit ein neues Instrument des Chirurgen…

Modifications of a nerve integrity monitor useful in skull base surgery.

1993

Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring

2016

Abstract Finite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

SU-G-201-02: Application of RayStretch in Clinical Cases: A Calculation for Heterogeneity Corrections in LDR Permanent I-125 Prostate Brachytherapy

2016

Purpose: Tissue heterogeneities and calcifications have significant impact on the dosimetry of low energy brachytherapy (BT). RayStretch is an analytical algorithm developed in our institution to incorporate heterogeneity corrections in LDR prostate brachytherapy. The aim of this work is to study its application in clinical cases by comparing its predictions with the results obtained with TG-43 and Monte Carlo (MC) simulations. Methods: A clinical implant (71 I-125 seeds, 15 needles) from a real patient was considered. On this patient, different volumes with calcifications were considered. Its properties were evaluated in three ways by i) the Treatment planning system (TPS) (TG-43), ii) a M…

Towards clinical application of RayStretch for heterogeneity corrections in LDR permanent 125-I prostate brachytherapy

2017

Purpose RayStretch is a simple algorithm proposed for heterogeneity corrections in low-dose–rate brachytherapy. It is built on top of TG-43 consensus data, and it has been validated with Monte Carlo (MC) simulations. In this study, we take a real clinical prostate implant with 71 125I seeds as reference and we apply RayStretch to analyze its performance in worst-case scenarios. Methods and Materials To do so, we design two cases where large calcifications are located in the prostate lobules. RayStretch resilience under various calcification density values is also explored. Comparisons against MC calculations are performed. Results Dose–volume histogram–related parameters like prostate D90, …

Die Sonoanatomie des Spinalkanales der LWS

2008

UNLABELLED Results of an Experimental Study and Report of Intraoperative Application: AIM Intraoperative sonography has been used in neurosurgery (especially in tumors) and in traumatology (assess reduction of dorsal vertebral body fragments). This study was performed to determine the value of sonography in detecting vertebral disc tissue. RESULTS We examined 6 specimens of the Lumbar spine using the extended flavectomy approach. We found that sono-anatomy was reproducible and that the assessable area was large enough to make sonography useful for detection of sequesters. Dislocated vertebral disc tissue could be differentiated clearly from original disc tissue and from other intraspinal st…

Evidence, Lack of Evidence, Controversy, and Debate in the Provision and Performance of the Surgery of Acute Type A Aortic Dissection

2011

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or t…

Navigated Transcranial Magnetic Stimulation Motor Mapping Usefulness in the Surgical Management of Patients Affected by Brain Tumors in Eloquent Area…

2021

Background: The surgical strategy for brain glioma has changed, shifting from tumor debulking to a more careful tumor dissection with the aim of a gross-total resection, extended beyond the contrast-enhancement MRI, including the hyperintensity on FLAIR MR images and defined as supratotal resection. It is possible to pursue this goal thanks to the refinement of several technological tools for pre and intraoperative planning including intraoperative neurophysiological monitoring (IONM), cortico-subcortical mapping, functional MRI (fMRI), navigated transcranial magnetic stimulation (nTMS), intraoperative CT or MRI (iCT, iMR), and intraoperative contrast-enhanced ultrasound. This systematic re…

Unusual recurrence of trigeminal neuralgia after microvascular decompression by muscle interposal.

2011

Summary Background Patients with trigeminal neuralgia (TN) and persistent or recurrent facial pain after microvascular decompression (MVD) typically undergo less invasive procedures in the hope of providing pain relief. However, re-operation should be considered in selected patients. Case Report A 48-year-old woman presented with recurrent trigeminal neuralgia (TN) 3 years following microvascular decompression (MVD). The patient underwent brain magnetic resonance angiography (MRA), which did not reveal neurovascular compression; therefore surgical re-exploration was carried out. During the operation, the fifth cranial nerve was seen without impingement from any blood vessels; however, a ver…

Role of  1-Adrenoceptor Subtypes in Pupil Dilation Studied With Gene-Targeted Mice

2014

PURPOSE The α₁A-adrenoceptor (α₁A-AR) subtype was suggested to mediate contraction and trophic effects in the iris dilator muscle, and thus its pharmacological blockade may be involved in intraoperative floppy iris syndrome. We tested the hypothesis that the α₁A-AR mediates pupil dilation and trophic effects in the mouse iris. METHODS The α₁-AR subtype mRNA expression was quantified in iris tissue by real-time PCR. To assess the role of individual α₁-ARs for mediating pupil dilation, the α₁-AR agonist phenylephrine was topically applied to the ocular surface of mice deficient in one of the three α₁-AR subtypes (α₁A-AR(-/-), α₁B-AR(-/-), α₁D-AR(-/-), respectively) and wild-type controls. Cha…