Radiologic Outcomes after Operative Management of Traumatic Spine Fractures: Stand-Alone Posterior Stabilization versus Combined Anteroposterior Approach.

BACKGROUND: Previous research emphasizes correcting deformities resulting from spine fractures by restoring sagittal alignment and vertebral height. This study aims to compare radiologic outcomes, including sagittal index (SI) and loss of vertebral body height (LVBH), between stand-alone posterior stabilization (group I) and the posteroanterior/combined approach (group II) in the operative management of traumatic thoracic or lumbar spine fractures. METHODS: In this retrospective single-center study, all patients with traumatic spine fractures (T1-L5) undergoing surgical stabilization between January 1, 2015, and May 31, 2021, were included. Two spine surgeons independently assessed imaging, recording the SI and LVBH values at baseline, after each surgical intervention, and during follow-up (at least 3 months posttreatment). The mean SI and LVBH values between the assessing surgeons were utilized. Linear mixed-effects regression models, adjusted to baseline values, compared the SI and the LVBH values between the two groups. RESULTS: In all, 71 patients (42 men), with the median age of 38 years (interquartile range [IQR]: 28-54) and median follow-up of 4 months (IQR: 3-17), were included. Thirty-two patients were in group I and 39 patients were in group II. Forty fractures included the thoracolumbar junction (T12 or L1), 15 affected the thoracic spine, and 14 the lumbar spine. The regression model revealed superior sagittal alignment in group II, with an adjusted mean difference for SI of -4.24 (95% confidence interval [CI]: -7.13 to -1.36; p = 0.004), and enhanced restoration of vertebral body height with an adjusted mean difference for LVBH of 0.11 in the combined approach (95% CI: 0.02-0.20; p = 0.02). Nine postoperative complications occurred in the entire cohort (4 in group I and 5 in group II). CONCLUSIONS: Combined posteroanterior stabilization for spine fractures improves deformities by enhancing sagittal alignment and increasing vertebral body height, with acceptable morbidity compared with the stand-alone posterior approach.

Concurrent Activation of Both Survival-Promoting and Death-Inducing Signaling by Chloroquine in Glioblastoma Stem Cells: Implications for Potential Risks and Benefits of Using Chloroquine as Radiosensitizer.

Lysosomotropic agent chloroquine was shown to sensitize non-stem glioblastoma cells to radiation in vitro with p53-dependent apoptosis implicated as one of the underlying mechanisms. The in vivo outcomes of chloroquine or its effects on glioblastoma stem cells have not been previously addressed. This study undertakes a combinatorial approach encompassing in vitro, in vivo and in silico investigations to address the relationship between chloroquine-mediated radiosensitization and p53 status in glioblastoma stem cells. Our findings reveal that chloroquine elicits antagonistic impacts on signaling pathways involved in the regulation of cell fate via both transcription-dependent and transcription-independent mechanisms. Evidence is provided that transcriptional impacts of chloroquine are primarily determined by p53 with chloroquine-mediated activation of pro-survival mevalonate and p21-DREAM pathways being the dominant response in the background of wild type p53. Non-transcriptional effects of chloroquine are conserved and converge on key cell fate regulators ATM, HIPK2 and AKT in glioblastoma stem cells irrespective of their p53 status. Our findings indicate that pro-survival responses elicited by chloroquine predominate in the context of wild type p53 and are diminished in cells with transcriptionally impaired p53. We conclude that p53 is an important determinant of the balance between pro-survival and pro-death impacts of chloroquine and propose that p53 functional status should be taken into consideration when evaluating the efficacy of glioblastoma radiosensitization by chloroquine.

Intermodal Detection of Lumbar Instability in Degenerative Spondylolisthesis is Superior to Functional Radiographs.

Purpose: In this study, we compare different imaging modalities to find the most sensitive and efficient way of detecting instability in lumbar spondylolisthesis. Methods: Patients presenting with spondylolisthesis from June 01, 2018 to May 31, 2020 with functional radiographs and either CT scans or MRI images were included in our single-center retrospective cohort study. The amount of translation, in millimeters, was measured on supine MRI images, CT scans, and radiographs of inclination while sitting, standing, or prone and reclination while standing using the Meyerding technique. The amount of translation was compared among the different modalities. Results: A total of 113 patients with spondylolisthesis on 125 vertebral levels were included in this study. The mean patient age was 73.52 ± 12.59 years; 69 (60.5%) patients were females. The most affected level was L4/5 (62.4%), followed by L3/4 (16%) and L5/S1 (13.6%). The average translations measured on supine CT were 4.13 ± 5.93 mm and 4.42 ± 3.49 mm on MRI (p = 0.3 for the difference between MRI and CT). The difference of inclination while sitting radiograph to slice imaging was 3.37 ± 3.64 mm (p < 0.0001), inclination while standing to slice imaging was 2.67 ± 3.03 mm (p < 0.0001), reclination while standing to slice imaging was 1.6 ± 3.15 mm (p = 0.03), and prone to slice imaging was 2.19 ± 3.02 mm (p = 0.03). Conclusion: We found that a single radiograph in either inclination, reclination, or prone position compared to a CT scan or an MRI image in supine position can detect instability in spondylolisthesis more efficiently than comparison of functional radiographs in any position.

Algorithmically Deduced FREM2 Molecular Pathway Is a Potent Grade and Survival Biomarker of Human Gliomas.

Gliomas are the most common malignant brain tumors with high mortality rates. Recently we showed that the FREM2 gene has a role in glioblastoma progression. Here we reconstructed the FREM2 molecular pathway using the human interactome model. We assessed the biomarker capacity of FREM2 expression and its pathway as the overall survival (OS) and progression-free survival (PFS) biomarkers. To this end, we used three literature and one experimental RNA sequencing datasets collectively covering 566 glioblastomas (GBM) and 1097 low-grade gliomas (LGG). The activation level of deduced FREM2 pathway showed strong biomarker characteristics and significantly outperformed the FREM2 expression level itself. For all relevant datasets, it could robustly discriminate GBM and LGG (p < 1.63 × 10-13, AUC > 0.74). High FREM2 pathway activation level was associated with poor OS in LGG (p < 0.001), and low PFS in LGG (p < 0.001) and GBM (p < 0.05). FREM2 pathway activation level was poor prognosis biomarker for OS (p < 0.05) and PFS (p < 0.05) in LGG with IDH mutation, for PFS in LGG with wild type IDH (p < 0.001) and mutant IDH with 1p/19q codeletion(p < 0.05), in GBM with unmethylated MGMT (p < 0.05), and in GBM with wild type IDH (p < 0.05). Thus, we conclude that the activation level of the FREM2 pathway is a potent new-generation diagnostic and prognostic biomarker for multiple molecular subtypes of GBM and LGG.

Intratumoral Heterogeneity and Longitudinal Changes in Gene Expression Predict Differential Drug Sensitivity in Newly Diagnosed and Recurrent Glioblastoma.

Background: Inevitable recurrence after radiochemotherapy is the major problem in the treatment of glioblastoma, the most prevalent type of adult brain malignancy. Glioblastomas are notorious for a high degree of intratumor heterogeneity manifest through a diversity of cell types and molecular patterns. The current paradigm of understanding glioblastoma recurrence is that cytotoxic therapy fails to target effectively glioma stem cells. Recent advances indicate that therapy-driven molecular evolution is a fundamental trait associated with glioblastoma recurrence. There is a growing body of evidence indicating that intratumor heterogeneity, longitudinal changes in molecular biomarkers and specific impacts of glioma stem cells need to be taken into consideration in order to increase the accuracy of molecular diagnostics still relying on readouts obtained from a single tumor specimen. Methods: This study integrates a multisampling strategy, longitudinal approach and complementary transcriptomic investigations in order to identify transcriptomic traits of recurrent glioblastoma in whole-tissue specimens of glioblastoma or glioblastoma stem cells. In this study, 128 tissue samples of 44 tumors including 23 first diagnosed, 19 recurrent and 2 secondary recurrent glioblastomas were analyzed along with 27 primary cultures of glioblastoma stem cells by RNA sequencing. A novel algorithm was used to quantify longitudinal changes in pathway activities and model efficacy of anti-cancer drugs based on gene expression data. Results: Our study reveals that intratumor heterogeneity of gene expression patterns is a fundamental characteristic of not only newly diagnosed but also recurrent glioblastomas. Evidence is provided that glioblastoma stem cells recapitulate intratumor heterogeneity, longitudinal transcriptomic changes and drug sensitivity patterns associated with the state of recurrence. Conclusions: Our results provide a transcriptional rationale for the lack of significant therapeutic benefit from temozolomide in patients with recurrent glioblastoma. Our findings imply that the spectrum of potentially effective drugs is likely to differ between newly diagnosed and recurrent glioblastomas and underscore the merits of glioblastoma stem cells as prognostic models for identifying alternative drugs and predicting drug response in recurrent glioblastoma. With the majority of recurrent glioblastomas being inoperable, glioblastoma stem cell models provide the means of compensating for the limited availability of recurrent glioblastoma specimens.

The approach angle to the interoptic triangle limits surgical workspace when targeting the contralateral internal carotid artery.

BACKGROUND: The interoptic triangle (IOT) offers a key access to the contralateral carotid artery's ophthalmic segment (oICA) and its perforating branches (PB), the ophthalmic artery (OA), and the superior hypophyseal artery (SHA). It has been previously reported that the assessment of IOT's size is relevant when attempting approaches to the contralateral oICA. However, previous studies have overseen that, since the oICA is a paramedian structure and a lateralized contralateral approach trajectory is then required, the real access to the oICA is further limited by the approach angle adopted by the surgeon with respect to the IOT's plane. For this reason, we determined the surgical accessibility to the contralateral oICA and its branches though the IOT by characterizing the morphometry of this triangle relative to the optimal contralateral approach angle. METHODS: We defined the "relative interoptic triangle" (rIOT) as the two-dimensional projection of the IOT to the surgeon's view, when the microscope has been positioned with a certain angle with respect to the midline to allow the maximal contralateral oICA visualization. We correlated the surface of the rIOT to the visualization of oICA, OA, SHA, and PBs on 8 cadavers and 10 clinical datasets, using for the last a 3D-virtual reality system. RESULTS: A larger rIOT correlated positively with the exposure of the contralateral oICA (R = 0.967, p < 0.001), OA (R = 0.92, p < 0.001), SHA (R = 0.917, p < 0.001), and the number of perforant vessels of the oICA visible (R = 0.862, p < 0.001). The exposed length of oICA, OA, SHA, and number PB observed increased as rIOT's surface enlarged. The correlation patterns observed by virtual 3D-planning matched the anatomical findings closely. CONCLUSIONS: The exposure of contralateral oICA, OA, SHA, and PB directly correlates to rIOT's surface. Therefore, preoperative assessment of rIOT's surface is helpful when considering contralateral approaches to the oICA. A virtual 3D planning tool greatly facilitates this assessment.

Comprehensive Anatomic Assessment of Ipsilateral Pterional Versus Contralateral Subfrontal Approaches to the Internal Carotid Ophthalmic Segment: A Cadaveric Study and Three-Dimensional Simulation.

OBJECTIVE: Medially pointing aneurysms of the ophthalmic segment of the internal carotid artery (oICA) represent a neurosurgical challenge. Conventional ipsilateral approaches require internal carotid artery and optic nerve (ON) mobilization as well as anterior clinoidectomy (AC), all associated with increased surgical risk. Contralateral approaches could provide a better exposure of the superomedial aspect of the oICA, ophthalmic artery, and superior hypophyseal artery, sparing AC and internal carotid artery or ON mobilization. However, the microsurgical anatomy of this approach has not been systematically studied. In the present work, we exhaustibly analyzed the anatomic and morphometric characteristics of contralateral approaches to the oICA and compared them with those from ipsilateral approaches. METHODS: We assessed 36 ipsilateral and contralateral approaches to the oICAs in cadaveric specimens and live patients, using for the latter a three-dimensional virtual reality (VR) system. RESULTS: Contralateral approaches spared sylvian fissure dissection and required only minimal frontal lobe retraction. The ipsilateral and contralateral oICA were found at a depth of 49.2 ± 1.8 mm (VR, 50.1 ± 2.92 mm) and 65.1 ± 1.5 mm (VR, 66.05 ± 3.364 mm) respectively. The exposure of the superomedial aspect of oICA was 7.25 ± 0.86 mm (VR: 6 ± 1 mm) contralaterally without ON mobilization and 2.44 ± 0.51 mm (VR, 2 ± 1 mm) ipsilaterally even after AC. Statistical analysis showed that, for nonprefixed chiasm, contralateral approaches achieved a significantly higher exposure of the ophthalmic artery, superior hypophyseal artery, and the superomedial aspect of the oICA with its perforating branches (all P < 0.01). CONCLUSIONS: Contralateral approaches may enable successful exposure of the oICA and related vascular structures, reducing the need for AC or ON mobilization. Systematic clinical/surgical studies are needed to further determine the effectiveness and safety of the approach.

A literature review concerning contralateral approaches to paraclinoid internal carotid artery aneurysms.

Ipsilateral approaches remain the standard technique for clipping paraclinoid aneurysms. Surgeons must however be prepared to deal with bony and neural structures restricting accessibility. The application of a contralateral approach has been proposed claiming that some structures in the region can be better exposed from this side. Yet, only few case series have been published evaluating this approach, and there is a lack of systematic reviews assessing its specific advantages and disadvantages. We performed a structured literature search and identified 19 relevant publications summarizing 138 paraclinoid aneurysms operated via a contralateral approach. Patient's age ranged from 19 to 79 years. Aneurysm size mainly varied between 2 and 10 mm and only three articles reported larger aneurysms. Most aneurysms were located at the origin of the ophthalmic artery, followed by the superior hypophyseal artery and carotid cave. All aneurysm protruded from the medial aspect of the carotid artery. Interestingly, minimal or even no optic nerve mobilization was required during exposure from the contralateral side. Strategies to achieve proximal control of the carotid artery were balloon occlusion and clinoid segment or cervical carotid exposure. Successful aneurysm occlusion was achieved in 135 cases, while 3 ophthalmic aneurysms had to be wrapped only. Complications including visual deterioration, CSF fistula, wound infection, vasospasm, artery dissection, infarction, and anosmia occurred in a low percentage of cases. We conclude that a contralateral approach can be effective and should be considered for clipping carefully selected cases of unruptured aneurysms arising from medial aspects of the above listed vessels.

Rates of Upper Facet Joint Violation in Minimally Invasive Percutaneous and Open Instrumentation: A Comparative Cohort Study of Different Insertion Techniques.

BACKGROUND: Minimally invasive pedicle screw placement may have a higher incidence of violation of the superior cephalad unfused facet joint. STUDY AIMS: We investigated the incidence and risk factors of upper facet joint violation in percutaneous robot-assisted instrumentation versus percutaneous fluoroscopy-guided and open transpedicular instrumentation. METHODS: A retrospective study including all consecutive patients who underwent lumbar instrumentation, fusion, and decompression for spondylolisthetic stenosis and degenerative disk disease was conducted between January 2012 and January 2016. All operations were performed by the same surgeon; the patients were divided into three groups according to the method of instrumentation. Group 1 involved the robot-assisted instrumentation in 58 patients, group 2 consisted of 64 patients treated with a percutaneous transpedicular instrumentation using fluoroscopic guidance, and 72 patients in group 3 received an open midline approach for pedicle screw insertion. RESULTS: Superior segment facet joint violation occurred in 2 patients in the robot-assisted group 1 (7%), in 22 of the percutaneous fluoroscopy-guided group 2 (34%), and in 6 cases of the open group (8%). The incidence of facet joint violation was present in 5% (3) of the screws in group 1, 22% (28) of the screws in group 2, and 3% (4) of the screws in group 3. CONCLUSION: Meticulous surgical planning of the appropriate entry site (Weinstein's method), trajectory planning, and proper robot-assisted instrumentation of pedicle screws reduced the risk of superior segment facet joint violation.

Navigation and Image Injection for Control of Bone Removal and Osteotomy Planes in Spine Surgery.

BACKGROUND AND IMPORTANCE: In contrast to cranial interventions, neuronavigation in spinal surgery is used in few applications, not tapping into its full technological potential. We have developed a method to preoperatively create virtual resection planes and volumes for spinal osteotomies and export 3-D operation plans to a navigation system controlling intraoperative visualization using a surgical microscope's head-up display. The method was developed using a Sawbone ® model of the lumbar spine, demonstrating feasibility with high precision. Computer tomographic and magnetic resonance image data were imported into Amira ® , a 3-D visualization software. Resection planes were positioned, and resection volumes representing intraoperative bone removal were defined. Fused to the original Digital Imaging and Communications in Medicine data, the osteotomy planes were exported to the cranial version of a Brainlab ® navigation system. A navigated surgical microscope with video connection to the navigation system allowed intraoperative image injection to visualize the preplanned resection planes. CLINICAL PRESENTATION: The workflow was applied to a patient presenting with a congenital hemivertebra of the thoracolumbar spine. Dorsal instrumentation with pedicle screws and rods was followed by resection of the deformed vertebra guided by the in-view image injection of the preplanned resection planes into the optical path of a surgical microscope. Postoperatively, the patient showed no neurological deficits, and the spine was found to be restored in near physiological posture. CONCLUSION: The intraoperative visualization of resection planes in a microscope's head-up display was found to assist the surgeon during the resection of a complex-shaped bone wedge and may help to further increase accuracy and patient safety.

Optimization of Catheter Based rtPA Thrombolysis in a Novel In Vitro Clot Model for Intracerebral Hemorrhage.

Hematoma lysis with recombinant tissue plasminogen activator (rtPA) has emerged as an alternative therapy for spontaneous intracerebral hemorrhage (ICH). Optimal dose and schedule are still unclear. The aim of this study was to create a reliable in vitro blood clot model for investigation of optimal drug dose and timing. An in vitro clot model was established, using 25 mL and 50 mL of human blood. Catheters were placed into the clots and three groups, using intraclot application of rtPA, placebo, and catheter alone, were analyzed. Dose-response relationship, repetition, and duration of rtPA treatment and its effectiveness in aged clots were investigated. A significant relative end weight difference was found in rtPA treated clots compared to catheter alone (p = 0.002) and placebo treated clots (p < 0.001). Dose-response analysis revealed 95% effective dose around 1 mg rtPA in 25 and 50 mL clots. Approximately 80% of relative clot lysis could be achieved after 15 min incubation. Lysis of aged clots was less effective. A new clot model for in vitro investigation was established. Our data suggest that current protocols for rtPA based ICH therapy may be optimized by using less rtPA at shorter incubation times.

A novel minimally invasive, dorsolateral, tubular partial odontoidectomy and autologous bone augmentation to treat dens pseudarthrosis: cadaveric, 3D virtual simulation study and technical report.

OBJECTIVE The goal of this study was to demonstrate the clinical and technical nuances of a minimally invasive, dorsolateral, tubular approach for partial odontoidectomy, autologous bone augmentation, and temporary C1-2 fixation to treat dens pseudarthrosis. METHODS A cadaveric feasibility study, a 3D virtual reality reconstruction study, and the subsequent application of this approach in 2 clinical cases are reported. Eight procedures were completed in 4 human cadavers. A minimally invasive, dorsolateral, tubular approach for odontoidectomy was performed with the aid of a tubular retraction system, using a posterolateral incision and an oblique approach angle. Fluoroscopy and postprocedural CT, using 3D volumetric averaging software, were used to evaluate the degree of bone removal of C1-2 lateral masses and the C-2 pars interarticularis. Two clinical cases were treated using the approach: a 23-year-old patient with an odontoid fracture and pseudarthrosis, and a 35-year-old patient with a history of failed conservative treatment for odontoid fracture. RESULTS At 8 cadaveric levels, the mean volumetric bone removal of the C1-2 lateral masses on 1 side was 3% ± 1%, and the mean resection of the pars interarticularis on 1 side was 2% ± 1%. The median angulation of the trajectory was 50°, and the median distance from the midline of the incision entry point on the skin surface was 67 mm. The authors measured the diameter of the working channel in relation to head positioning and assessed a greater working corridor of 12 ± 4 mm in 20° inclination, 15° contralateral rotation, and 5° lateral flexion to the contralateral side. There were no violations of the dura. The reliability of C-2 pedicle screws and C-1 lateral mass screws was 94% (15 of 16 screws) with a single lateral breach. The patients treated experienced excellent clinical outcomes. CONCLUSIONS A minimally invasive, dorsolateral, tubular odontoidectomy and autologous bone augmentation combined with C1-2 instrumentation has the ability to provide excellent 1-stage management of an odontoid pseudarthrosis. The procedure can be completed safely and successfully with minimal blood loss and little associated morbidity. This approach has the potential to provide not only a less invasive approach but also a function-preserving option to treat complex C1-2 anterior disease.

A Modified Microsurgical Endoscopic-Assisted Transpedicular Corpectomy of the Thoracic Spine Based on Virtual 3-Dimensional Planning.

BACKGROUND AND OBJECTIVE: The main difficulties of transpedicular corpectomies are lack of space for vertebral body replacement in the neighborhood of critical structures, the necessity for sacrifice of nerve roots in the thoracic spine. and the extent of hemorrhage due to venous epidural bleeding. We present a modified technique of transpedicular corpectomy by using an endoscopic-assisted microsurgical technique performed through a single posterior approach. A 3-dimensional (3D) preoperative reconstruction could be helpful in the planning for this complex anatomic region. METHODS: Surface and volume 3D reconstruction were performed by Amira or the Dextroscope. The clinical experience of this study includes 7 cases, 2 with an unstable burst fracture and 5 with metastatic destructive vertebral body disease, all with significant retropulsion and obstruction of the spinal canal. We performed a comparison with a conventional cohort of transpedicular thoracic corpectomies. RESULTS: Qualitative parameters of the 3D virtual reality planning included degree of bone removal and distance from critical structures such as myelon and implant diameter. Parameters were met in each case, with demonstration of optimal positioning of the implant without neurological complications. In all patients, the endoscope was a significant help in identifying the origins of active bleeding, residual tumor, extent of bone removal, facilitating cage insertion in a minimally invasive way, and helping to avoid root sacrifice on both sides. CONCLUSIONS: Microsurgical endoscopic-assisted transpedicular corpectomy may prove valuable in enhancing the safety of corpectomy in destructive vertebral body disease. The 3D virtual anatomic model greatly facilitated the preoperative planning.

C-OnSite ® for intraoperative 3D control of pedicular screw positions.

BACKGROUND: Two-dimensional image guidance and navigation can help to reduce the number of misplaced pedicle screws, but do not completely prevent misplacement. This experimental, retrospective, non-inferiority study was designed to evaluate and compare the efficacy of a novel 3D imaging technique versus conventional postoperative CT-scan, for intra-operative determination of pedicle screw position accuracy. METHODS: The capacity of C-OnSite® to intraoperatively assess screw placement was evaluated in 28 clinical cases and 23 deliberately misplaced screws in a cadaver model, and compared to placement accuracy determined by standard CT. The position of each implant, as viewed by both modalities, was graded by three neurosurgeons, one orthopaedic-surgeon and one radiologist. The intermodal variance determined the difference between CT- and C-OnSite® results for each observer, while the inter-observer variance measured the difference between ratings of the same modality by different observers. RESULTS: C-OnSite® successfully assessed 120/138 screws (25/28 cases). Mean procedural fluoroscopy time was 132 ± 51 s, and 40 ± 16s per C-OnSite® scan. The average inter-modality variance was ,15 % with mismatches >1° between C-OnSite® and the gold-standard imaging technique in only 2 % of the comparisons. Average inter-observer variances were about similar (12 % for CT and 18 % for C-OnSite®), with deviations of >1° reaching 1 % for CT and 3 % for C-OnSite®. Individual variances between experienced only observers differed even less. CONCLUSIONS: C-OnSite® is a feasible, reliable and intuitive means of intraoperatively visualizing pedicle screw positions and might render the majority of postoperative CTs superfluous. C-OnSite® might help avoid re-operations for screw re-positioning.

Image-guided implantation of pre-calibrated catheters in the ICU: a feasibility study.

BACKGROUND: Image-guided implantation of intracranial catheters is a routine procedure. Although time for surgery is short, transport from the intensive care unit (ICU) to the operation room (OR) is time-consuming and endangers patients in vulnerable intracranial pressure phases. Unfortunately, technical aspects of image guidance have so far required surgery to be performed in the operation room. In this observational study we investigated the feasibility of image-guided catheter placement in the ICU using a pre-calibrated stylet for implantation of intracranial catheters for a variety of indications and compare the results of procedures performed in the OR. METHODS: Twenty-three patients received implantation of 31 image-guided intracranial catheters or external ventricular drains using a pre-calibrated stylet in the ICU or in the OR. The times required for navigation planning, transport and surgery were assessed. Pre-operative trajectory planning, intra-operative screenshots of the navigation system and postoperative computed tomography (CT) scans were compared. RESULTS: Eleven external ventricular drains and nine intracranial catheters for fibrinolytic therapy of intracerebral haemorrhage were implanted in the OR, whereas ten external ventricular drains and one catheter for fibrinolytic therapy were implanted in the ICU. All catheters implanted on the ICU, 81.8 % of external ventricular drains and 88.8 % of lysis catheters placed in the OR had an optimal position to function. CONCLUSION: A pre-calibrated stylet in combination with the flexible headband equipped with reference arrays allows the application of image guidance in the ICU. It reduced time expended for patients and employees, and avoided the risks of ICU transport to the OR.

Perioperative course and accuracy of screw positioning in conventional, open robotic-guided and percutaneous robotic-guided, pedicle screw placement.

Robotic-guided and percutaneous pedicle screw placement are emerging technologies. We here report a retrospective cohort analysis comparing conventional open to open robotic-guided and percutaneous robotic-guided pedicle screw placement. 112 patient records and CT scans were analyzed concerning the intraoperative and perioperative course. 35 patients underwent percutaneous, 20 open robotic-guided and 57 open conventional pedicle screw placement. 94.5% of robot-assisted and 91.4% of conventionally placed screws were found to be accurate. Percutaneous robotic and open robotic-guided subgroups did not differ obviously. Average X-ray exposure per screw was 34 s in robotic-guided compared to 77 s in conventional cases. Subgroup analysis indicates that percutaneously operated patients required less opioids, had a shorter hospitalization and lower rate of adverse events in the perioperative period. The use of robotic guidance significantly increased accuracy of screw positioning while reducing the X-ray exposure. Patients seem to have a better perioperative course following percutaneous procedures.

Occlusion of surgical opening of the ventricular system with fibrinogen-coated collagen fleece: a case collection study.

BACKGROUND: Implantation of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) wafer for malignant glioma is not recommended in the case of surgical opening of the ventricular system during microsurgical tumor resection because the wafer material may dislocate from the resection cavity into the ventricular system and cause obstructive hydrocephalus. TachoSil is an adhesive collagen fleece used in different surgical disciplines that provides an air- and liquid-tight seal closing communications between the ventricular system and the resection cavity after tumor removal. METHODS: Occlusion of ventricular defects with TachoSil after microsurgical glioma resection was performed in two patients with newly diagnosed and seven patients with recurrent malignant glioma prior to BCNU wafer implantation into the resection cavity. Early postoperative cranial computed tomography (CCT)/MRI and follow-up MRI at 3 months' intervals were performed with a median follow-up of 10.4 months. RESULTS: The collagen fleece was identified as a linear structure hypodense/hypointense to white matter on postoperative CT/MRI separating the resection cavity from the ventricular lumen in all cases. In no case did early CCT/MRI or follow-up MRI reveal wafer material within the ventricular system. In no case did signs of obstructive hydrocephalus occur. CONCLUSION: Sealing of the ventricular system using a fibrinogen-coated collagen fleece effectively separates the resection cavity from the ventricular system and allows implantation of BCNU wafers into the resection cavity. No morphological evidence for wafer material dislocation into the ventricular system or obstruction of CSF pathways was found in nine patients who received 41 follow-up MRI over 10.4 months of follow-up.

Safety and efficacy of a new percutaneously implantable interspinous process device.

BACKGROUND: Lumbar spinal stenosis is a degenerative disease of the elderly population. Although microsurgical decompression has shown good long-term results, percutaneous techniques could provide an alternative in the presence of significant comorbidities. METHOD: Eighty-seven interspinous process decompression devices (In-space; Synthes, Umkirch, Germany) were implanted percutaneously in up to three segments of 50 patients. Outcome was assessed directly after surgery, at 6-8 weeks, and at average follow-up of 1 year (11.8 ± 6 months). Assessment included complications, pain and spinal claudication, neurodeficit, time to recurrence of symptoms, and time to second surgery. Subgroups with additional low back pain at presentation and mild spondylolisthesis were analyzed separately. FINDINGS: Intraoperative complications were rare (one misplacement and two cases of failed implantation); average operation time was 16.4 ± 12.2 min per segment. Initial response was very good with 72% good or excellent relief of symptoms. After a 1-year follow-up, 42% reported of lasting relief from spinal claudication. Thirteen percent of these complained about lasting or new-onset low back pain. A second surgery had been performed in 22%. Subgroup analysis was performed for patients presenting with additional low back pain and spondylolisthesis patients. No significant differences could be noted between subgroups. CONCLUSIONS: The In-space is a percutaneous treatment option of claudication in patients with lumbar spinal stenosis. Compared with microsurgical decompression surgery, recurrence rate within 1 year is, however, high and the device seems not suitable for the treatment of low back pain. Therefore, the authors suggest that the device should presently be used primarily in controlled clinical trials in order to get more information concerning the optimal indication.

A transmedullary approach to occlusion of a ventral perimedullary arteriovenous fistula of the thoracic spinal cord.

OBJECTIVE: A spinal perimedullary arteriovenous fistula (PMAVF) is a direct fistula of one or more spinal arteries into the perimedullary venous network with reversed venous flow and subsequent venous congestion of the spinal cord. The therapeutic goal of surgery is to normalize the venous drainage by obliterating the fistula. Strictly ventral lesions typically require an anterior approach to ensure adequate exposure of the fistula as well and the preservation of the physiological blood supply to the spinal cord. CLINICAL PRESENTATION: We present a case of a ventral PMAVF at the level of T10 with feeders from the anterior spinal artery, caudally draining veins on the ventral spinal cord, and a dilated transmedullary vein filling cranially draining veins on the dorsal aspect of the spinal cord. TECHNIQUE: The dilated transmedullary vein was approached by a laminectomy. The vein was coagulated, and the gliotic channel was used to approach the ventral fistula site from the dorsal surface of the spinal cord. Complete obliteration of the fistula was achieved, and the preoperative neurological deficit improved. CONCLUSION: We conclude that transmedullarly draining veins offers a possible dorsal approach for the occlusion of some ventral PMAVFs, thus avoiding more complex anterior approaches to the ventral spinal cord.

Robot-assisted image-guided transcranial magnetic stimulation for somatotopic mapping of the motor cortex: a clinical pilot study.

PURPOSE: Shape and exact location of motor cortical areas varies among individuals. The exact knowledge of these locations is crucial for planning of neurosurgical procedures. In this study, we have used robot-assisted image-guided transcranial magnetic stimulation (Ri-TMS) to elicit MEP response recorded for individual muscles and reconstruct functional motor maps of the primary motor cortex. METHODS: One healthy volunteer and five patients with intracranial tumors neighboring the precentral gyrus were selected for this pilot study. Conventional MRI and fMRI were obtained. Transcranial magnetic stimulation was performed using a MagPro X100 stimulator and a standard figure-of-eight coil positioned by an Adept Viper s850 robot. The fMRI activation/Ri-TMS response pattern were compared. In two cases, Ri-TMS was additionally compared to intraoperative direct electrical cortical stimulation. RESULTS: Maximal MEP response of the m. abductor digiti minimi was located in an area corresponding to the "hand knob" of the precentral gyrus for both hemispheres. Repeated Ri-TMS measurements showed a high reproducibility. Simultaneous registration of the MEP response for m. brachioradialis, m. abductor pollicis brevis, and m. abductor digiti minimi demonstrated individual peak areas of maximal MEP response for the individual muscle groups. Ri-TMS mapping was compared to the corresponding fMRI studies. The areas of maximal MEP response localized within the "finger tapping" activated areas by fMRI in all six individuals. CONCLUSIONS: Ri-TMS is suitable for high resolution non-invasive preoperative somatotopic mapping of the motor cortex. Ri-TMS may help in the planning of neurosurgical procedures and may be directly used in navigation systems.