Ultrasound-based navigated pedicle screw insertion without intraoperative radiation: feasibility study on porcine cadavers

BACKGROUND Navigation systems for spinal fusion surgery rely on intraoperative computed tomography (CT) or fluoroscopy imaging. Both expose patient, surgeons and operating room staff to significant amounts of radiation. Alternative methods involving intraoperative ultrasound (iUS) imaging have recently shown promise for image-to-patient registration. Yet, the feasibility and safety of iUS navigation in spinal fusion have not been demonstrated. PURPOSE To evaluate the accuracy of pedicle screw insertion in lumbar and thoracolumbar spinal fusion using a fully automated iUS navigation system. STUDY DESIGN Prospective porcine cadaver study. METHODS Five porcine cadavers were used to instrument the lumbar and thoracolumbar spine using posterior open surgery. During the procedure, iUS images were acquired and used to establish automatic registration between the anatomy and preoperative CT images. Navigation was performed with the preoperative CT using tracked instruments. The accuracy of the system was measured as the distance of manually collected points to the preoperative CT vertebral surface and compared against fiducial-based registration. A postoperative CT was acquired, and screw placements were manually verified. We report breach rates, as well as axial and sagittal screw deviations. RESULTS A total of 56 screws were inserted (5.50 mm diameter n=50, and 6.50 mm diameter n=6). Fifty-two screws were inserted safely without breach. Four screws (7.14%) presented a medial breach with an average deviation of 1.35±0.37 mm (all <2 mm). Two breaches were caused by 6.50 mm diameter screws, and two by 5.50 mm screws. For vertebrae instrumented with 5.50 mm screws, the average axial diameter of the pedicle was 9.29 mm leaving a 1.89 mm margin in the left and right pedicle. For vertebrae instrumented with 6.50 mm screws, the average axial diameter of the pedicle was 8.99 mm leaving a 1.24 mm error margin in the left and right pedicle. The average distance to the vertebral surface was 0.96 mm using iUS registration and 0.97 mm using fiducial-based registration. CONCLUSIONS We successfully implanted all pedicle screws in the thoracolumbar spine using the ultrasound-based navigation system. All breaches recorded were minor (<2 mm) and the breach rate (7.14%) was comparable to existing literature. More investigation is needed to evaluate consistency, reproducibility, and performance in surgical context. CLINICAL SIGNIFICANCE Intraoperative US-based navigation is feasible and practical for pedicle screw insertion in a porcine model. It might be used as a low-cost and radiation-free alternative to intraoperative CT and fluoroscopy in the future

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression

Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (&lt; 5 years, 5–10 years, 10–20 years, and &gt; 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (&lt; 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs &gt; 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (&lt; 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs &gt; 20 years: 0.62), and only surgeons with &gt; 20 years of experience did not have substantial reliability on assessment 2 (&lt; 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs &gt; 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

Διερεύνηση της ανατομικής ακρίβειας του συστήματος νευροπλοήγησης StealthStation σε επεμβάσεις νευροχειρουργικής

Stereotaxy was the first well-established and traditionally the gold standard method of targeting intracranial structures. The extensive refinement of the stereotactic devices along with the development of MRI in the 1990s and a large number of relevant publications with consistent results rendered the frame-based stereotactic brain biopsy the gold standard technique for brain biopsies, too. (Hall 1998, Yu, Liu et al. 2000, Heper, Erden et al. 2005) However, the stereotactic method is characterized by various important disadvantages: 1) the patient’s discomfort, 2) the necessity of a new CT/MRI scan immediately preoperatively, 3) the requirement of calculating and verifying the coordinates, 4) the head frames themselves, which may restrict both the anesthesiologist and the surgeon, and 5) the fact that biopsy specimens can be acquired intraoperatively only from the targets defined preoperatively. (Goldstein, Gumerlock et al. 1987, Matsumoto, Tomita et al. 1995, Lozano, Gildenberg et al. 2009, Shooman, Belli et al. 2010)Modern intraoperative navigation systems provide several significant advantages, e.g. multiplanar image reconstruction (axial, coronal, sagittal, probe’s eye view) and 3D pre- and intra-operative planning, real-time intraoperative surgical instrument guidance, and precise localization of intracranial targets. (Bale, Laimer et al. 2006, Georgiopoulos, Ellul et al. 2014) Moreover, in the case of brain biopsies they are combined with miniframe stereotactic devices. As a result, the various disadvantages of the stereotactic methods and apparatuses (e.g. Cosman-Roberts-Wells (CRW) or Leksell systems) can be avoided.In order to perform a brain biopsy, a biopsy needle must be inserted accurately and safely into the selected target. Therefore, a reliable targeting device (stereotactic apparatus or navigation system) is necessary, as well as a device that holds steadily the needle in the pre-specified trajectory as it is inserted, i.e. a needle guide attached on the stereotactic device or a miniframe device.Regarding Trigeminal Neuralgia (TGN), percutaneous balloon compression (PBC) is a very reliable technique, which along with radiofrequency thermo-coagulation (RFT), they are the most effective percutaneous methods in the long term. Additionally, it is characterized by a relatively lower and milder morbidity than microvascular decompression and RFT (16.1% vs 29.2%), which also includes avoidance of anesthesia dolorosa and keratitis, while it is appropriate for involvement of the ophthalmic division. (Lopez, Hamlyn et al. 2004, Tatli, Satici et al. 2008, Toda 2008) Moreover, the patients are not obligated to cooperate, while they are sedated avoiding pain and stress. However, failure to cannulate the foramen ovale (FO) (with any of the percutaneous methods) using only fluoroscopy is a significant problem in some cases, due to various possible reasons, i.e. inadequate visualization of the FO, presence of anatomical variations (smaller size, intraforaminal bony ridges or ossified pterygospinous/pterygoalar ligament) or in the case of PBC, the thick Tuohy needle. In addition, the exposure to radiation might be significant for the surgeon, while multiple attempts of cannulation could increase the risk of complications. (Georgiopoulos, Ellul et al. 2014)The first purpose of the present thesis was to compare the characteristics, i.e. efficacy, duration of each procedure, safety and length of hospitalization, of a frameless fiducial-less brain biopsy method with those of the standard frame-based stereotactic technique. Secondly, in this thesis, we have also suggested a treatment alternative: the use of an optical navigation system (StealthStation® S7™, Medtronic Inc., Minneapolis, MN, USA) for the guidance of PBC for TGN, in cases of reoperation after prior failure to cannulate the FO under fluoroscopy only. Overall, the purpose of the present thesis was to evaluate the anatomical accuracy of the neuronavigation system StealthStation in neurosurgical operations, specifically in brain biopsy and PBC procedures; by assessing the efficacy, the targeting accuracy and the safety of the StealthStation navigated operations, compared with the standard respective techniques.Brain biopsies, Patients/Materials and Methods: In the present prospective cohort study were enrolled 56 adult patients: 1) for whom no conclusive diagnosis could be settled in a noninvasive manner; and 2a) who also had lesions involving deeply seated and eloquent areas, or multifocal lesions, or lesions for which the probable diagnosis is a contraindication for craniotomy, or 2b) were poor candidates for craniotomy (over 80 years old or serious comorbidities that were considered contraindications for craniotomy). 28 patients were operated on with each method. Regarding the frameless biopsy technique, we used an optical navigation system (StealthStation® S7™) without fiducials in combination with the Navigus miniframe device (burr-hole-mounted, ball-and-socket device). Concerning the frame-based stereotactic method we used the CRW stereotactic system and planning software (FrameLink™ Stereotactic Planning Software).Brain biopsies, Results: Failure of diagnosis was recorded in 4 cases (14.3%) of the frame-based method group and 3 cases (10.7%) of the frameless fiducial-less method group, in spite of the accurate targeting, without a statistically significant difference (p= 1.0). The smallest maximal diameter of a lesion successfully targeted, acquiring samples which led to a diagnosis, was 15mm for both groups. The mean duration of the overall procedure was 111.3min for the frame-based method and 79.1min for the frameless method, which was clearly a statistically significant difference (p= 0.001). Both the duration of the preparatory steps overall and of the preparation inside the operating room (OR) concerning the frame-based technique were significantly longer than the duration of the preparation overall – inside the OR of the frameless method. However, there was not a statistically significant difference between the two groups regarding either the operation’s duration (“skin-to-skin”) or the time spent inside the OR overall. Concerning neurologic morbidity, new abnormal findings in the postoperative head CT scan (p= 1.0) and postoperative hospital stay (p= 0.66) the two methods did not differ significantly.Navigated PBC, Patients/Materials and Methods: A total of 174 patients underwent PBC for TGN from 2003 to 2012. In 9 cases the penetration of the FO was not accomplished. Five of those patients were re-operated for PBC using navigation. Preoperatively, a head CT scan is performed and the acquired images are imported into the navigation system (StealthStation® S7™). Intraoperatively, a small reference frame is strapped firmly to the patient’s forehead, the CT images are registered, and cannulation is performed under the guidance of the navigation system and then confirmed by fluoroscopy.Navigated PBC, Results: In all patients, the operation overall was completed successfully. Moreover, all patients reported complete pain relief immediately postoperatively and no complications were recorded.The frameless fiducial-less brain biopsy method, described in the present thesis, was shown to be equally efficacious and safe, compared with the standard stereotactic frame-based technique, in terms of diagnostic yield, neurologic complications, and new abnormal findings in the postoperative head CT scan. In addition, the frameless fiducial-less method was associated with a shorter duration of the overall procedure and of the preparation overall – inside the OR, in comparison with the frame-based technique. Finally, the two methods resulted in similar duration of postoperative hospitalization. (Georgiopoulos, Ellul et al. 2017) Furthermore, the frameless fiducial-less technique does not involve the aforementioned disadvantages of the frame-based technique, while it is more flexible preoperatively and intraoperatively. Consequently, it could be hypothesized that it is friendlier to the patient and more comfortable for the surgeon, and seems to provide a more simplified workflow for both the operating room and the hospital overall.Secondly, the surgical management of unsuccessful PBC, and percutaneous treatments in general, due to various reasons remains controversial. In this thesis, we suggest the use of navigation for the guidance of the cannulation of the FO during PBC, in cases of prior failure to penetrate into the FO under fluoroscopy only. At least when our study was published, we had not encountered any other paper analyzing the application of a navigation system, without impractical special targeting/navigation devices/adjuncts, intraoperative imaging systems or immobilization of the head, specifically for PBC and TGN, after prior failure to cannulate the FO under fluoroscopy only. (Georgiopoulos, Ellul et al. 2014) This technique involves technology with significant advantages helping the successful cannulation of the FO and seems more convenient, more efficient and safer.Η τεχνική της στερεοταξίας ήταν η πρώτη καλά τεκμηριωμένη και παραδοσιακά η “gold standard” μέθοδος στόχευσης ενδοκράνιων δομών. Η εκτενής βελτίωση των στερεοτακτικών συσκευών μαζί με την ανάπτυξη της Μαγνητικής Τομογραφίας (MRI) τη δεκαετία του 90 και ένας μεγάλος αριθμός σχετικών μελετών με σταθερά αποτελέσματα καθιέρωσαν τη στερεοτακτική βιοψία εγκεφάλου βασισμένη σε πλαίσιο ως τη “gold standard” τεχνική και για τις βιοψίες εγκεφάλου. (Hall 1998, Yu, Liu et al. 2000, Heper, Erden et al. 2005) Παρόλα αυτά, η στερεοτακτική μέθοδος χαρακτηρίζεται από διάφορα σημαντικά μειονεκτήματα: 1) τη δυσανεξία εκ μέρους του ασθενή, 2) την αναγκαιότητα νέας λήψης Αξονικής τομογραφίας (CT)/MRI άμεσα προεγχειρητικά, 3) την απαίτηση υπολογισμού και επαλήθευσης των συντεταγμένων, 4) τα πλαίσια κεφαλής αυτά καθεαυτά, που μπορεί να εμποδίζουν τόσο τον αναισθησιολόγο όσο και τον χειρουργό, και 5) το γεγονός ότι τα δείγματα βιοψίας δύναται να ληφθούν διεγχειρητικά μόνο από τους στόχους που ορίστηκαν προεγχειρητικά. (Goldstein, Gumerlock et al. 1987, Matsumoto, Tomita et al. 1995, Lozano, Gildenberg et al. 2009, Shooman, Belli et al. 2010)Τα σύγχρονα συστήματα πλοήγησης προσφέρουν διάφορα σημαντικά πλεονεκτήματα, π.χ. ανακατασκευές εικόνων διαφόρων όψεων (π.χ. εγκάρσια, στεφανιαία, οβελιαία και «κορυφής καθετήρα») και τρισδιάστατο προ- και δι-εγχειρητικό προγραμματισμό, πραγματικού χρόνου διεγχειρητική καθοδήγηση των χειρουργικών εργαλείων και ακριβή εντόπιση ενδοκράνιων στόχων. (Bale, Laimer et al. 2006, Georgiopoulos, Ellul et al. 2014) Επιπλέον, στην περίπτωση των βιοψιών εγκεφάλου συνδυάζονται με συσκευές τύπου mini πλαισίου. Ως αποτέλεσμα, τα διάφορα μειονεκτήματα των στερεοτακτικών μεθόδων και συσκευών (π.χ. Cosman-Roberts-Wells (CRW) ή Leksell σύστημα) μπορούν να αποφευχθούν.Για να διενεργηθεί μια βιοψία εγκεφάλου, μια βελόνα βιοψίας πρέπει να εισαχθεί με ακρίβεια και ασφάλεια στον επιλεγμένο στόχο. Κατά συνέπεια, μια αξιόπιστη συσκευή στόχευσης (στερεοτακτική συσκευή ή σύστημα πλοήγησης) είναι απαραίτητη, όπως επίσης και μια συσκευή που να κρατάει σταθερά τη βελόνα στην προκαθορισμένη πορεία καθώς εισάγεται, π.χ. ένας οδηγός βελόνας προσαρτημένος στη στερεοτακτική συσκευή ή μια συσκευή τύπου mini πλαισίου.Σχετικά με τη Νευραλγία Τριδύμου (TGN), η διαδερμική συμπίεση με μπαλόνι (PBC) είναι μια πολύ αξιόπιστη τεχνική, που μαζί με τη θερμοπηξία με ραδιοσυχνότητες (RFT), είναι οι πιο αποτελεσματικές διαδερμικές μέθοδοι μακροπρόθεσμα. Επιπροσθέτως, χαρακτηρίζεται από σχετικά χαμηλότερη και ηπιότερη θνητότητα από ότι η μικροαγγειακή αποσυμπίεση και η RFT (16.1% εναντίον 29.2%), που επίσης περιλαμβάνει αποφυγή της «επώδυνης αναισθησίας» και της κερατίτιδας, ενώ είναι κατάλληλη και σε προσβολή του οφθαλμικού κλάδου. (Lopez, Hamlyn et al. 2004, Tatli, Satici et al. 2008, Toda 2008) Επιπλέον, οι ασθενείς δε χρειάζεται να συνεργαστούν, ενώ είναι υπό γενική αναισθησία αποφεύγοντας το άλγος και το stress. Παρόλα αυτά, αποτυχία εισαγωγής στο ωοειδές τρήμα (FO) (με οποιαδήποτε από τις διαδερμικές μεθόδους) χρησιμοποιώντας μόνο ακτινόσκοπηση είναι ένα σημαντικό πρόβλημα σε κάποιες περιπτώσεις, εξαιτίας διαφόρων αιτιών, π.χ. ανεπαρκής ακτινοσκοπική ανάδειξη του FO, παρουσία ανατομικών παραλλαγών (μικρότερο μέγεθος, ενδοτρηματικές οστικές ακρολοφίες ή οστεοποιημένος πτερυγοσπονδυλικός ή pterygoalar σύνδεσμος) ή στην περίπτωση της PBC, η ευρεία βελόνα τύπου Tuohy. Επιπρόσθετα, η έκθεση στην ακτινοβολία θα μπορούσε να είναι σημαντική για το χειρουργό, ενώ πολλαπλές προσπάθειες εισόδου στο FO θα μπορούσε να αυξήσει το κίνδυνο επιπλοκών. (Georgiopoulos, Ellul et al. 2014)Ο πρώτος σκοπός αυτής της διατριβής ήταν να συγκρίνει τα χαρακτηριστικά, δηλαδή αποτελεσματικότα, διάρκεια κάθε διαδικασίας, ασφάλεια και διάρκεια νοσηλείας, μιας μεθόδου βιοψίας εγκεφάλου χωρίς πλαίσιο ούτε fiducials (καθοδηγούμενη από πλοήγηση) με αυτά της τυπικής βασισμένης σε πλαίσιο στερεοτακτικής τεχνικής. Δεύτερο, σε αυτή τη διατριβή, προτείναμε επίσης μια εναλλακτική μέθοδο αντιμετώπισης: τη χρήση ενός οπτικού συστήματος πλοήγησης (StealthStation® S7™, Medtronic Inc., Minneapolis, MN, USA) για την καθοδήγηση της τεχνικής PBC για TGN, σε περιπτώσεις επανεπέμβασης, μετά από προηγούμενη αποτυχία εισόδου στο FO υπό ακτινοσκόπηση μόνο. Συνολικά, ο σκοπός της παρούσας διατριβής ήταν να εκτιμήσουμε την ανατομική ακρίβεια του συστήματος νευροπλοήγησης StealthStation σε νευροχειρουργικές επεμβάσεις, συγκεκριμένα σε επεμβάσεις βιοψίας εγκεφάλου και PBC, ελέγχοντας την αποτελεσματικότητα, την ακρίβεια στόχευσης και την ασφάλεια των επεμβάσεων καθοδηγούμενων από το σύστημα StealthStation, σε σύγκριση με τις αντίστοιχες κλασικές τεχνικές.Βιοψίες εγκεφάλου, Ασθενείς/Υλικό και Μέθοδος: Στην παρούσα προοπτική μελέτη κοόρτης συμμετείχαν 56 ενήλικες ασθενείς: 1) για του οποίους δεν υπήρξε οριστική διάγνωση με μη επεμβατικό τρόπο και οι οποίοι 2α) είχαν βλάβες σε εν τω βάθει ή κρίσιμες περιοχές ή πολυεστιακές βλάβες ή βλάβες για τις οποίες η πιθανή διάγνωση είναι αντένδειξη για κρανιοτομή ή 2β) ήταν ακατάλληλοι υποψήφιοι για κρανιοτομή (ηλικία >80 έτη ή σοβαρή συννοσηρότητα που θεωρήθηκε αντένδειξη για κρανιοτομή). 28 ασθενείς χειρουργήθηκαν με κάθε μια από τις δυο μεθόδους. Σχετικά με τη τεχνική βιοψία χωρίς πλαίσιο, χρησιμοποιήσαμε ένα οπτικό σύστημα πλοήγησης (StealthStation® S7™) χωρίς fiducials σε συνδυασμό με τη συσκευή mini πλαισίου Navigus (τοποθετούμενη σε κρανιοανάτρηση, τύπου σφαίρας-και-θήκης). Σχετικά με τη στερετοτακτική μέθοδο βασισμένη σε πλαίσιο χρησιμοποιήσαμε το στερεοτακτικό σύστημα CRW και software προεγχειρητικού προγραμματισμού (FrameLink™ Stereotactic Planning Software).Βιοψίες εγκεφάλου, Αποτελέσματα: Αποτυχία διάγνωσης καταγράφηκε σε 4 περιπτώσεις (14.3%) στην ομάδα μεθόδου πλαισίου και σε 3 περιπτώσεις (10.7%) στην ομάδα μεθόδου χωρίς πλαίσιο – fiducials, παρά την ακριβή στόχευση, χωρίς στατιστικά σημαντική διαφορά (p= 1.0). Η μικρότερη μέγιστη διάμετρος βλάβης που στοχεύθηκε επιτυχώς, λαμβάνοντας δείγματα που οδήγησαν στη διάγνωση, ήταν 15mm και για τις δυο ομάδες. Η μέση διάρκεια της συνολικής διαδικασίας ήταν 111.3min για την ομάδα μεθόδου πλαισίου και 79.1min για την ομάδα μεθόδου χωρίς πλαίσιο, η οποία ήταν ξεκάθαρα μια στατιστικά σημαντική διαφορά (p= 0.001). Τόσο η διάρκεια των προπαρασκευαστικών βημάτων συνολικά όσο και της προετοιμασίας μέσα στη χειρουργική αίθουσα που αφορούσε στην τεχνική βασισμένη σε πλαίσιο ήταν σημαντική μεγαλύτερη από ότι η διάρκεια της προετοιμασίας συνολικά – μέσα στη χειρουργική αίθουσα της μεθόδου χωρίς πλαίσιο. Παρόλα αυτά, δεν υπήρξε στατιστικά σημαντική διαφορά μεταξύ των δυο ομάδων σχετικά είτε με τη διάρκεια της επέμβασης αυτής καθεαυτή («δέρμα με δέρμα») ή του χρόνου που καταναλώθηκε μέσα στη χειρουργική αίθουσα συνολικά. Σχετικά με τη νευρολογική νοσηρότητα, νέα παθολογικά ευρήματα στη μετεγχειρητική CT εγκεφάλου (p= 1.0) και της μετεγχειρητικής νοσηλείας (p= 0.66) οι δυο μέθοδοι δε διέφεραν σημαντικά.PBC πλοηγούμενη, Ασθενείς/Υλικό και Μέθοδοι: Συνολικά 174 ασθενείς υποβλήθηκαν σε PBC για TGN από το 2003 έως το 2012. Σε 9 περιπτώσεις η είσοδος στο FO δεν επετεύχθη. Πέντε από αυτούς τους ασθενείς υποβλήθηκαν εκ νέου σε PBC χρησιμοποιώντας πλοήγηση. Προεγχειρητικά, διενεργήθηκε CT εγκεφάλου και οι εικόνες εισήχθησαν στο σύστημα πλοήγησης (StealthStation® S7™). Διεγχειρητικά ένα μικρό πλαίσιο αναφοράς σταθεροποιείται σφιχτά στο μέτωπο του ασθενούς, οι εικόνες της CT εγγράφονται και η είσοδος στο FO διενεργείται υπό την καθοδήγηση του συστήματος πλοήγησης και μετά επιβεβαιώνεται ακτινοσκοπικά.PBC πλοηγούμενη, Αποτελέσματα: Σε όλους τους ασθενείς η επέμβαση συνολικά ολοκληρώθηκε επιτυχώς. Επιπλέον, όλοι οι ασθενείς ανέφεραν πλήρη ανακούφιση του άλγους άμεσα μετεγχειρητικά και δεν καταγράφηκε καμία επιπλοκή.Η μέθοδος βιοψίας εγκεφάλου χωρίς πλαίσιο – fiducials, που περιγράφηκε στην παρούσα διδακτορική διατριβή, δείχθηκε ότι ήταν εξίσου αποτελεσματική και ασφαλής, σε σύγκριση με την τυπική στερεοτακτική τεχνική βασισμένη σε πλαίσιο, όσον αφορά στη διαγνωστική δυνατότητα, νευρολογικές επιπλοκές και νέα παθολογικά ευρήματα στη μετεγχειρητική CT εγκεφάλου. Επιπροσθέτως, η μέθοδος χωρίς πλαίσιο – fiducials συσχετίστηκε με συντομότερη διάρκεια της συνολικής διαδικασίας και της προετοιμασίας συνολικά – μέσα στη χειρουργική αίθουσα, σε σύγκριση με την τεχνική βασισμένη σε πλαίσιο. Τέλος, οι δυο μέθοδοι κατέληξαν σε παρόμοια διάρκεια μετεγχειρητικής νοσηλείας. (Georgiopoulos, Ellul et al. 2017) Επιπλέον, η τεχνική χωρίς πλαίσιο – fiducials δε συμπεριλαμβάνει τα προαναφερθέντα μειονεκτήματα της τεχνικής βασισμένη σε πλαίσιο, ενώ είναι πιο ευέλικτη προεγχειρητικά και διεγχειρητικά. Κατά συνέπεια, θα μπορούσε να υποτεθεί ότι είναι φιλικότερη προς τον ασθενή και πιο άνετη για το χειρουργό και δείχνει να παρέχει μια πιο απλοποιημένη ροή εργασίας τόσο για τη χειρουργική αίθουσα όσο και για το νοσοκομείο γενικότερα.Δεύτερον, η χειρουργική αντιμετώπιση της ανεπιτυχούς PBC, και των διαδερμικών τεχνικών γενικότερα, οφειλόμενη σε διάφορους λόγους παραμένει αμφιλεγόμενη. Σε αυτή τη διδακτορική διατριβή, προτείνουμε τη χρήση της πλοήγησης για καθοδήγηση της εισόδου στο FO κατά τη PBC, σε περιπτώσεις προηγηθείσας αποτυχίας εισόδου υπό ακτινοσκόπηση μόνο. Τουλάχιστον όταν δημοσιεύθηκε η μελέτη μας, δεν ανακαλύψαμε άλλη μελέτη που να αναλύει την εφαρμογή ενός συστήματος πλοήγησης χωρίς μη πρακτικά πλαίσια/συσκευές πλοήγησης/στόχευσης, συστήματα διεγχειρητικής απεικόνισης ή ακινητοποίησης της κεφαλής συγκεκριμένα για PBC και TGN, μετά από προηγηθείσα αποτυχία εισόδου στο FO υπό ακτινοσκόπηση μόνο. (Georgiopoulos, Ellul et al. 2014) Αυτή η τεχνική συμπεριλαμβάνει τεχνολογία με σημαντικά πλεονεκτήματα που βοηθάει την επιτυχή είσοδο στο FO και δείχνει πιο πρακτική, πιο αποτελεσματική και πιο ασφαλής

Adult Spinal Deformity Surgery and Frailty: A Systematic Review.

Study designSystematic review.ObjectivesAdult spinal deformity (ASD) can be a debilitating condition with a profound impact on patients' health-related quality of life (HRQoL). Many reports have suggested that the frailty status of a patient can have a significant impact on the outcome of the surgery. The present review aims to identify all pre-operative patient-specific frailty markers that are associated with postoperative outcomes following corrective surgery for ASD of the lumbar and thoracic spine.MethodsA systematic review of the literature was performed to identify findings regarding pre-operative markers of frailty and their association with postoperative outcomes in patients undergoing ASD surgery of the lumbar and thoracic spine. The search was performed in the following databases: PubMed, Embase, Cochrane and CINAHL.ResultsAn association between poorer performance on frailty scales and worse postoperative outcomes. Comorbidity indices were even more frequently employed with similar patterns of association between increased comorbidity burden and postoperative outcomes. Regarding the assessment of HRQoL, worse pre-operative ODI, SF-36, SRS-22 and NRS were shown to be predictors of post-operative complications, while ODI, SF-36 and SRS-22 were found to improve post-operatively.ConclusionsThe findings of this review highlight the true breadth of the concept of "frailty" in ASD surgical correction. These parameters, which include frailty scales and various comorbidity and HRQoL indices, highlight the importance of identifying these factors preoperatively to ensure appropriate patient selection while helping to limit poor postoperative outcomes

Modulating the activity of human nociceptors with a SCN10A promoter-specific viral vector tool

Despite the high prevalence of chronic pain as a disease in our society, there is a lack of effective treatment options for patients living with this condition. Gene therapies using recombinant AAVs are a direct method to selectively express genes of interest in target cells with the potential of, in the case of nociceptors, reducing neuronal firing in pain conditions. We designed a recombinant AAV vector expressing cargos whose expression was driven by a portion of the SCN10A (NaV1.8) promoter, which is predominantly active in nociceptors. We validated its specificity for nociceptors in mouse and human dorsal root ganglia and showed that it can drive the expression of functional proteins. Our viral vector and promoter package drove the expression of both excitatory or inhibitory DREADDs in primary human DRG cultures and in whole cell electrophysiology experiments, increased or decreased neuronal firing, respectively. Taken together, we present a novel viral tool that drives expression of cargo specifically in human nociceptors. This will allow for future specific studies of human nociceptor properties as well as pave the way for potential future gene therapies for chronic pain

Systemic considerations for the surgical treatment of spinal metastatic disease: a scoping literature review.

Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been comprehensively summarised. We aimed to conduct a scoping literature review of this broad topic. We searched MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and CINAHL databases from Jan 1, 2000, to July 31, 2021. 61 articles were included, accounting for a total of 22 335 patients. Preoperative systemic variables negatively associated with postoperative clinical outcomes included demographics (eg, older age [&gt;60 years], Black race, male sex, low or elevated body-mass index, and smoking status), medical comorbidities (eg, cardiac, pulmonary, hepatic, renal, endocrine, vascular, and rheumatological), biochemical abnormalities (eg, hypoalbuminaemia, atypical blood cell counts, and elevated C-reactive protein concentration), low muscle mass, generalised motor weakness (American Spinal Cord Injury Association Impairment Scale grade and Frankel grade) and poor ambulation, reduced performance status, and systemic disease burden. This is the first comprehensive scoping review to broadly summarise emerging evidence relevant to the systemic assessment component of the widely used NOMS framework for spinal metastatic disease decision making. Medical, surgical, and radiation oncologists can consider these findings when prognosticating spinal metastatic disease-related surgical outcomes on the basis of patients' systemic condition. These factors might inform a shared decision-making approach with patients and their families

Procedures performed during neurosurgery residency in Europe

International audienceAbstract Background In a previous article ( 10.1007/s00701-019-03888-3 ), preliminary results of a survey, aiming to shed light on the number of surgical procedures performed and assisted during neurosurgery residency in Europe were reported. We here present the final results and extend the analyses. Methods Board-certified neurosurgeons of European Association of Neurosurgical Societies (EANS) member countries were asked to review their residency case logs and participate in a 31-question electronic survey (SurveyMonkey Inc., San Mateo, CA). The responses received between April 25, 2018, and April 25, 2020, were considered. We excluded responses that were incomplete, from non-EANS member countries, or from respondents that have not yet completed their residency. Results Of 430 responses, 168 were considered for analysis after checking in- and exclusion criteria. Survey responders had a mean age of 42.7 ± 8.8 years, and 88.8% were male. Responses mainly came from surgeons employed at university/teaching hospitals (85.1%) in Germany (22.0%), France (12.5%), the United Kingdom (UK; 8.3%), Switzerland (7.7%), and Greece (7.1%). Most responders graduated in the years between 2011 and 2019 (57.7%). Thirty-eight responders (22.6%) graduated before and 130 responders (77.4%) after the European WTD 2003/88/EC came into effect. The mean number of surgical procedures performed independently, supervised or assisted throughout residency was 540 (95% CI 424–657), 482 (95% CI 398–568), and 579 (95% CI 441–717), respectively. Detailed numbers for cranial, spinal, adult, and pediatric subgroups are presented in the article. There was an annual decrease of about 33 cases in total caseload between 1976 and 2019 (coeff. − 33, 95% CI − 62 to − 4, p = 0.025). Variables associated with lesser total caseload during residency were training abroad (1210 vs. 1747, p = 0.083) and female sex by trend (947 vs. 1671, p = 0.111), whereas case numbers were comparable across the EANS countries ( p = 0.443). Conclusion The final results of this survey largely confirm the previously reported numbers. They provide an opportunity for current trainees to compare their own case logs with. Again, we confirm a significant decline in surgical exposure during training between 1976 and 2019. In addition, the current analysis reveals that female sex and training abroad may be variables associated with lesser case numbers during residency

An international validation of the AO spine subaxial injury classification system

Purpose To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions. Methods A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with associated computed tomography scans and key images. Intraobserver reproducibility and interobserver reliability of the AO Spine Subaxial Injury Classification System were calculated for injury morphology, injury subtype, and facet injury. The reliability and reproducibility of the classification system were categorized as slight (? = 0-0.20), fair (? = 0.21-0.40), moderate (? = 0.41-0.60), substantial (? = 0.61-0.80), or excellent (? = &gt; 0.80) as determined by the Landis and Koch classification. Results A total of 203 AO Spine members participated in the AO Spine Subaxial Injury Classification System validation. The percent of participants accurately classifying each injury was over 90% for fracture morphology and fracture subtype on both assessments. The interobserver reliability for fracture morphology was excellent (? = 0.87), while fracture subtype (? = 0.80) and facet injury were substantial (? = 0.74). The intraobserver reproducibility for fracture morphology and subtype were excellent (? = 0.85, 0.88, respectively), while reproducibility for facet injuries was substantial (? = 0.76). Conclusion The AO Spine Subaxial Injury Classification System demonstrated excellent interobserver reliability and intraobserver reproducibility for fracture morphology, substantial reliability and reproducibility for facet injuries, and excellent reproducibility with substantial reliability for injury subtype