Lateral Approach to the Cervical Spine to Manage Degenerative Cervical Myelopathy and Radiculopathy.

BACKGROUND: The cervical lateral approach can enlarge the spinal canal and foramen to achieve an effective neural decompression without needing spine stabilization. For this review, the authors' main objective was to illustrate the rationale, advantages, disadvantages, complications, and pitfalls of this technique, highlighting also areas for future development. MATERIALS AND METHODS: A Medline via PubMed database search was carried out by using both keywords, namely "cervical oblique corpectomy," "multilevel oblique corpectomy and foraminotomy," and "lateral vertebrectomy," and Medical Subject Headings (MeSH) terms from 1 January 1991, up to 31 December 2021. RESULTS: The analyzed articles suggested that the use of such a technique has declined over time; only 29 clinical studies met all the inclusion criteria and were retained for data analysis, including 1200 patients undergoing such an approach for the management of degenerative cervical myelopathies (DCMs) or of radiculopathies. The main etiopathogeneses were cervical stenosis, degenerative disk disease, or a mix of them-78% of which had a favorable outcome; the most frequent complications were transient and permanent Horner syndrome in 13.6% and 9.2% of cases, respectively. Long-term stability was reported in 97% of patients. CONCLUSION: Multilevel cervical oblique vertebrectomy and/or lateral foraminotomy allow wide neural structure decompression and optimal stability given that the physiological spinal motion is preserved.

Through the orbit and beyond: Current state and future perspectives in endoscopic orbital surgery on behalf of the EANS frontiers committee in orbital tumors and the EANS skull base section.

Introduction: Orbital surgery has always been disputed among specialists, mainly neurosurgeons, otorhinolaryngologists, maxillofacial surgeons and ophthalmologists. The orbit is a borderland between intra- and extracranial compartments; Krönlein's lateral orbitotomy and the orbitozygomatic infratemporal approach are the historical milestones of modern orbital-cranial surgery. Research question: Since its first implementation, endoscopy has significantly impacted neurosurgery, changing perspectives and approaches to the skull base. Since its first application in 2009, transorbital endoscopic surgery opened the way for new surgical scenario, previously feasible only with extensive tissue dissection. Material and methods: A PRISMA based literature search was performed to select the most relevant papers on the topic. Results: Here, we provide a narrative review on the current state and future trends in endoscopic orbital surgery. Discussion and conclusion: This manuscript is a joint effort of the EANS frontiers committee in orbital tumors and the EANS skull base section.

[Interdisciplinary surgery to the central skull base-current status]. / Interdisziplinäre Chirurgie der zentralen Schädelbasis ­ aktueller Stand.

BACKGROUND: The skull base is a surgically complex unit and is often only accessible via combined access routes. Newly developed surgical techniques using microsurgical visualization procedures and active instruments ("powered instruments") as well as multiport accesses enable new, less traumatic surgical corridors. This requires close interdisciplinary cooperation between ENT and neurosurgeons. Currently established access routes to the central skull base are systematized based on the authors' own clinical experience, and discussed in relation to the entity and the current study situation. MATERIALS AND METHODS: A retrospective, qualitative, and descriptive evaluation of the surgical reports of patients with pathologies of the central skull base who were jointly treated by neurosurgery and otorhinolaryngologic/head and neck surgery between 2006 and 2019 was performed. RESULTS: The surgical access routes to the central skull base can be categorized as so-called multiport access routes, partly also in combination, as follows: transnasal-transsphenoidal, subfrontal, subtemporal, transzygomatic, transpterygonal, transpetrous, translabyrinthine, and suboccipital. The choice of access route was based on the location and type of pathology, its inflammatory or space-occupying (benign or malignant tumor) nature, and the possibilities of functional preservation and complete removal. CONCLUSION: Due to the complexity of central skull base structures, the different tumor entities, and the required expertise of different medical specialties, surgery of the central skull base remains a challenge and should only be performed at special competence centers certified according to the criteria of the German Society of Skull Base Surgery.

[Cochlear nerve continuity preservation during retrosigmoid ablative osteotomy of the internal auditory canal for advanced vestibular schwannomas]. / Kontinuitätserhalt des Nervus cochlearis bei der retrosigmoidalen ablativen Osteotomie des inneren Gehörgangs bei fortgeschrittenen Vestibularisschwannomen.

The data of 86 patients with retrosigmoid microsurgical resection of vestibular schwannoma in tumor stage Koos II-IV were evaluated. In more than two thirds of the cases it was shown that the cochlear nerve followed the facial nerve, which is easily identified by electroneurography, in recurrent similar patterns in the region of the internal auditory canal. Starting from the fundus, this facilitated early identification and thus preservation of continuity of the cochlear nerve in the course of the internal auditory canal. This was of particular importance when safe functional preservation could not be guaranteed due to tumor size or formation despite intraoperative derivation of somatosenoric potentials, but when the possibility of subsequent hearing rehabilitation with a cochlear implant should be granted. Preoperative MRI sequences gave an indication of the possible nerve courses in some cases, but intraoperative imaging in the internal auditory canal was superior to MRI.

Surgical management of anterior clinoidal meningiomas: consensus statement on behalf of the EANS skull base section.

BACKGROUND: The optimal management of clinoidal meningiomas (CMs) continues to be debated. METHODS: We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of these tumors. The data from the literature along with contemporary practice patterns were discussed within the task force to generate consensual recommendations. RESULTS AND CONCLUSION: This article represents the consensus opinion of the task force regarding pre-operative evaluations, patient's counselling, surgical classification, and optimal surgical strategy. Although this analysis yielded only Class B evidence and expert opinions, it should guide practitioners in the management of patients with clinoidal meningiomas and might form the basis for future clinical trials.

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section.

BACKGROUND: The optimal management of petroclival meningiomas (PCMs) continues to be debated along with several controversies that persist. METHODS: A task force was created by the EANS skull base section along with its members and other renowned experts in the field to generate recommendations for the management of these tumors. To achieve this, the task force reviewed in detail the literature in this field and had formal discussions within the group. RESULTS: The constituted task force dealt with the existing definitions and classifications, pre-operative radiological investigations, management of small and asymptomatic PCMs, radiosurgery, optimal surgical strategies, multimodal treatment, decision-making, and patient's counselling. CONCLUSION: This article represents the consensually derived opinion of the task force with respect to the management of PCMs.

Minispectrometer with handheld probe for 5-ALA based fluorescence-guided surgery of brain tumors: Preliminary study for clinical applications.

INTRODUCTION: Recently a mini-spectrometer with a handheld probe quantifying 5-aminolevulinic acid (5-ALA) based fluorescence intensity of brain tumors was developped by Kim et al. to improve fluorescence-guided neurosurgery. OBJECTIVE: To evaluate if this new tool is capable to discriminate nuances of fluorescence intensity of strongly fluorescing tumors (glioblastomas (GBM) and meningiomas (MM)). To study different modes of measurement (touch/no-touch). To determine protoporphyrin IX (PPIX) concentration in tumor tissue as compared to a laboratory spectrometer. MATERIAL AND METHODS: The tumor tissue was resected from patients operated in the neurosurgical department of University Hospital Duesseldorf, Germany between 01/2014 and 06/2014. Two spectrometers, one custom-built with a handheld probe ("mini-spectrometer") and one commercial laboratory spectrometer were employed. After calibration they were used to detect and compare fluorescence intensity of human brain tumor samples ex vivo under standardized conditions. The mini-spectrometer was tested at different distances to the tumor. PPIX concentrations of tumor lysates were determined by both spectrometers. RESULTS: In total n=11 tumors (5 MM and 6 GBM) resulting in 17 tumor biopsies were studied. All GBM showed significant higher fluorescence intensity as compared to MM (Z=-3.123, p=0.001). The fluorescence signal was inversely proportional to the square of the distance (GBM: R2=0.226; F=4.683; p<0.5; MM: R2=0255; F=8.042; p<0.01). The mini-spectrometer recorded fluorescence signals up to 2mm ("no-touch"). Determination of PPIX concentration in tumor by the mini-spectrometer did not differ from a laboratory spectrometer. CONCLUSION: The mini-spectrometer was a very sensitive tool for detection of 5-ALA based fluorescence of human brain tumors. Fluorescence intensity of glioblastoma and meningioma were significantly different. A no-touch mode of measurement was possible. PPIX concentration in tumor tissue could be determined as precisely as with a laboratory spectrometer. In future clinical trials the practicability of using such a tool in vivo has to be further evaluated.

Impact of 5-aminolevulinic acid fluorescence-guided surgery on the extent of resection of meningiomas--with special regard to high-grade tumors.

BACKGROUND AND OBJECTIVES: In high-grade meningiomas and a subgroup of clinically aggressive benign meningiomas tumor control is still insufficient. Recently 5-ALA fluorescence in meningiomas was reported. The impact of 5-ALA fluorescence-guided surgery (FGS) on surgical decision-making and extent of resection has not yet been systematically analyzed, especially not in high-grade meningiomas. The present study deals with three main questions regarding 5-ALA FGS in meningiomas: to assess the potential for discriminating different WHO grades intra-operatively, to analyze the influence on surgical strategy and to evaluate the impact on extent of resection. METHODS: Data from 31 meningiomas operated with 5-ALA FGS were retrospectively analyzed. Intraoperative fluorescence was graded by the surgeon as "no", "low" or "high". Correlations between semi-quantitative fluorescence and histological features (WHO grade) were analyzed. The influence of 5-ALA fluorescence on surgical strategy and the impact of 5-ALA FGS on degree of resection (Simpson grade and post-operative imaging) were studied. In tumors showing infiltrative growth the extent of resection of fluorescence positive tissue was evaluated. RESULTS: The population comprised 19 WHO grade I, 8 grade II and 4 grade III tumors (61% benign and 39% high-grade meningiomas). 94% of the tumors showed positive fluorescence. Different fluorescence intensities were observed: "no" in two, "high" in 12 and "low" in 17 tumors, respectively. A significant correlation between fluorescence intensity and WHO grade was found (ρ=0.557, p=0.001). 5-ALA improved the extent of resection in 3/16 (19%) of grade I and in 6/8 (75%) of grade II/III meningiomas. This improvement was not measurable by the Simpson grading as rated by the surgeon and controlled on post-operative imaging. CONCLUSIONS: In the present population a strong correlation between fluorescence intensity and WHO grade was observed. 5-ALA FGS improved the extent of resection in meningiomas. Especially in high-grade tumors additional information on brain and neurovascular infiltration was provided. The improved resection was not measurable by Simpson's grading necessitating an additional item, which rates residual fluorescence. Long-term studies are necessary to evaluate a possible impact of FGS on recurrence and overall survival.

Giant cell tumor of the lumbar spine with intraperitoneal growth: case report and review of literature.

Giant cell tumors of the spine are uncommon. Usually they are benign and solitary, but locally very aggressive. Most of them occur at the sacral spine. There are only 26 reported cases in the literature involving this type of tumor in the lumbar spine, in particular exhibiting an intraperitoneal growth. We present the case of a woman with a primary tumor of the lumbar spine (giant cell tumor) with intraperitoneal growth, the outcome as well as a review of the literature. Furthermore, after reviewing all spinal cases in the literature above the sacral spine, we carefully suggest a management algorithm.

Skull bone flap fixation - reliability and efficacy of a new grip-like titanium device (Skull Grip) versus traditional sutures: a clinical randomized trial.

BACKGROUND: After completing a craniotomy, it is important to replace the removed bone flap in its natural position in order to guarantee brain protection as well as improve cosmesis. A skull defect can expose the brain to accidental damage, and in cases of larger defects it may also cause the patients psychosocial problems. The ideal fixation device should provide reliable attachment of the flap to the skull and promote fast bony healing to avoid possible pseudo-arthrosis and/or osteolytic changes. MATERIALS AND METHODS: This is a pilot randomized clinical trial on a series of 16 patients undergoing different craniotomies for benign brain lesions in which the bone flaps were replaced using traditional sutures (Prolene 0.0) in 8 cases and with a new skull fixation device (Skull Grip) in the other 8 (randomly allocated). All patients underwent CT scans of the head with 3D reconstruction at day 1 and day 90 postoperatively to evaluate bone flap position and fusion. These scans were independently reviewed by a neuroradiologist. Cosmesis was also evaluated clinically by the surgeon and radiologically by the neuroradiologist in the 2 patient groups. RESULTS: The new "Skull Grip" device has shown stronger fixation qualities with optimal bone flap fusion and increased cosmetic healing features vs. traditional sutures. CONCLUSION: The "Skull Grip" has shown to be a reliable, effective and stronger bone flap fixation device when compared to traditional sutures.

Oxygen-conserving reflexes of the brain: the current molecular knowledge.

The trigemino-cardiac reflex (TCR) may be classified as a sub-phenomenon in the group of the so-called 'oxygen-conserving reflexes'. Within seconds after the initiation of such a reflex, there is neither a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF) with no changes in the cerebral metabolic rate of oxygen (CMRO(2)) or in the cerebral metabolic rate of glucose (CMRglc). Such an increase in regional CBF without a change of CMRO(2) or CMRglc provides the brain with oxygen rapidly and efficiently and gives substantial evidence that the TCR is an oxygen-conserving reflex. This system, which mediates reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus which finally engage a small population of neurons in the cortex. This cortical centre appears to be dedicated to reflexively transduce a neuronal signal into cerebral vasodilatation and synchronization of electrocortical activity. Sympathetic excitation is mediated by cortical-spinal projection to spinal pre-ganglionic sympathetic neurons whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Better and more detailed knowledge of the cascades, transmitters and molecules engaged in such endogenous (neuro) protection may provide new insights into novel therapeutic options for a range of disorders characterized by neuronal death and into cortical organization of the brain.

Lumboperitoneal shunt for treatment of dural ectasia in ankylosing spondylitis.

Neurological complications of ankylosing spondylitis (AS) are reported in 2.1% of patients. Cauda equina syndrome (CES) is rare and occurs at the ankylosing stage. MRI and CT of the lumbar spine show a cauda equina deformation with dural ectasia and bony erosion. We report three patients with AS presenting with progressive CES. These patients underwent lumboperitoneal shunting (LPS) surgery. The motor deficit improved in all cases. We suggest that CES develops from arterial pulsation of the CSF on a dural sac with reduced elasticity and that LPS reduces these intradural pressure shock waves. A meta-analysis by Ahn et al. [Ahn NU, Ahn UM, Nallamshetty L, et al. Cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome): meta-analysis of outcomes after medical and surgical treatments. J Spinal Disord 2001;14:427-33] concludes that surgical treatment has a better outcome than conservative or no treatment. Adding our 3 patients to this analysis, it appears that LPS for CES in AS is more efficient than laminectomy. LPS is a routine procedure for a rare indication, which promises improvement or atleast a stabilization of this disabling evolution of the disease.

Double-door laminoplasty in managing multilevel myelopathy: technique description and literature review.

Cervical laminoplasty has become a popular technique for the treatment of cervical myelopathy resulting from multilevel canal stenosis. The goal of this technique is to increase the spinal canal space and to reconstruct the posterior bony arch at the same time. The most common reason for laminoplasty failure is restenosis because of hinge closure. In the present report, the authors describe a variation of the double-door laminoplasty using a specifically tailored plate. The present technique is a modification of the double-door laminoplasty by using a specifically developed plate (Senegas' Plate--by Stryker Technology, Kalamazoo, MI), which allows to fix the two hemilamina in an open and expanded position re-establishing also the posterior canal arch. This procedure was implemented in a series of 22 patients. The device has been successfully implanted in all patients. At a mean follow-up of 21.1 months all patients showed a remarkable neurological improvement documented by serial clinical and radiological investigations. The present study indicates that this specific device effectively preserves the postoperative sagittal cervical canal diameter and provides a rigid construct, and in addition, it is very easy and fast to apply minimizing the risk of iatrogenic injuries, blood loss, and operative time.

Bone tumors at the cranio-cervical junction. Surgical management and results from a series of 41 cases.

BACKGROUND: Bone tumors located at the cranio-cervical junction (CCJ)are rare. Tumoral involvement of the neighbouring structures including bone, nerves and vertebral artery and the dynamic aspects of the bone structures raise technical difficulties in the surgical approach. The surgical management includes tumoral resection and stabilization of the CCJ. METHODS: Forty-one patients presenting a bone tumor (26 benign and 15 malignant tumors), excluding chordomas, located at the CCJ (including lower third of the clivus, C1 and C2) were observed over 20 years from 1981 to 2001. Imaging work-up included CT scanner with bone windows sequences and reconstruction in the coronal and sagittal plane; since 1984 most of the patients (N=35) underwent a MRI and angioMR scanning. Vertebral angiography was rarely performed (N=9) and mostly when the diagnosis was doubtful. In some cases the diagnosis was clear but in others, imaging studies showed destructive lesions suggesting a malignancy, which sometimes required a biopsy (N=4). The surgical resection was only performed through a lateral approach. FINDINGS: Complete resection was achieved in 38 cases while in 3 cases a small remnant was left behind. A complementary stabilization procedure was necessary in 18 cases using either bone grafting during the same procedure and through the same approach (N=5) or a craniocervical plating and bone grafting (N=13). No recurrence in the group of benign tumors was seen during an average follow-up of 6 years (from 2 to 11 years). The pre-operative symptoms of pain and neck stiffness, improved or disappeared in most patients. Three patients with lower cranial nerves (N=2) or sphincter disturbances (N=1) remained unchanged. One patient with tetraplegia eventually died. CONCLUSIONS: Various types of bone tumors may be found at the CCJ. Confusion between benign and malignant tumor or pseudo tumors must be avoided, sometimes requiring a biopsy. Surgery using a lateral approach, usually permits the surgeon to achieve a complete resection either preserving the stability of the CCJ whenever intact or associated with a stabilization procedure.

Combined use of a radial fore arm free flap for extra-intracranial bypass and for antero-lateral skull base reconstruction--a new technique and review of literature.

This article describes a new surgical technique consisting of the combined use of a fascial radial fore arm free flap (RFFF) as vascular graft for extra-intracranial bypass and as dura mater plasty for reconstruction of the antero-lateral skull base. This new technique is illustrated by a case of a complex intracranial meningioma with extracranial extension necessitating resection of internal carotid artery. The technical issues of antero-lateral skull base reconstruction and extra-intracranial bypass are discussed and the literature is reviewed.

Combined use of prostacyclin and higher perfusate temperatures further enhances the superior lung preservation by Celsior solution in the isolated rat lung.

BACKGROUND: The poor tolerance of the lung to ischemia and reperfusion (IR) still represents one of the limitations in clinically successful lung transplantation. Modified Euro-Collins (EC) is routinely used in lung preservation, but alternative solutions have been developed for improvement of pulmonary preservation. Celsior is an extracellular solution that has significantly reduced the IR-induced pulmonary damage in animal studies. So far, no extensive experimental studies exist concerning the influence of Celsior on pulmonary gas exchange following IR. METHODS: In an extracorporeal rat lung model 10 lungs, each, were preserved with Celsior (CE) and Celsior/prostacyclin (CEPC, 6 microg/100 ml) at 4 degrees and 15 degrees C, each, and compared to low-potassium Euro-Collins (EC-40, 40 mmol/liter potassium). After 2 hours of ischemia lungs were reventilated and reperfused using a roller pump. Oxygenation in terms of oxygen partial tension in the left atrial effluent, pulmonary vascular resistance (PVR), peak inspiratory pressure, and wet/dry ratio were monitored for 50 minutes. Furthermore, edema formation was evaluated by light microscopy. Statistical analysis was performed using ANOVA models. RESULTS: Compared to the EC-40 group, oxygenation was increased and amount of edema was reduced in most Celsior-preserved organs (p<0.032) with exception of the CEPC group at 4 degrees C (p = 0.06). Additional application of prostacyclin did not have any significant effect on oxygenation in the Celsior group. However, after temperature elevation of the CEPC perfusate to 15 degrees C, a superior partial tension of oxygen was observed (p<0.023) in contrast to the 4 degrees C groups CE and CEPC. The lowest PVR was found in the CE 4 degrees C group (p<0.02). CONCLUSIONS: Celsior provides better lung preservation than EC-40 solution. Application of prostacyclin at higher perfusate temperatures results in additional functional improvement. In vivo experiments and ultrastructural analysis are warranted for further evaluation of Celsior in lung preservation.

Celsior solution for improvement of currently used clinical standards of lung preservation in an ex vivo rat model.

OBJECTIVE: The introduction of Euro-Collins solution with its intracellular electrolyte composition has allowed for clinically accepted pulmonary preservation for up to 7 h of ischemic time. In recent years several alternative solutions have been developed for the improvement of pulmonary preservation. Celsior is an extracellular solution which has significantly reduced the ischemia/reperfusion (IR)-induced pulmonary damage in animal studies. So far, no larger experimental studies exist concerning the influence of Celsior on pulmonary gas exchange following IR. METHODS: In an extracorporeal rat lung model ten lungs, were each preserved with Celsior (CE) and Celsior/ prostacycline (CEPC, 6 mg/100 ml) at 4 degrees C and compared with preservation with low-potassium-Euro-Collins solution (LPEC, 40 mmol/l of potassium). After 2 h of ischemia the lungs were re-ventilated and reperfused using a roller-pump. Relative oxygenation capacity (ROC), pulmonary vascular resistance (PVR), peak inspiratory pressure (PIP) and wet/dry ratio were monitored for 50 min. Statistical analysis was performed using ANOVA. RESULTS: ROC was increased in all Celsior preserved organs compared with the EC group (P < 0.032). Though the CEPC group was found to have the lowest PIP and the least amount of lung water as assessed by wet/dry ratio, PVR was highest after 30-50 min. The significantly lowest PVR was determined in the CE group (P < 0.02). CONCLUSIONS: Celsior provides better lung preservation than LPEC solution, as demonstrated by a significantly increased oxygenation ability, a lower PVR and a decreased wet/ dry ratio. In vivo experiments and additional histological analysis are warranted for further evaluation of Celsior in lung preservation.