Nuance in Craniovertebral Junction Surgical Approach for Posterior C1-C2 Harms Stabilization: "Window Transposition" of the External Vertebral Venous Plexus for Bloodless C1 Lateral Mass Screw Insertion: Anatomical Aspects and Technical Notes.

Atlas and axis instrumentation may be necessary in cases of several craniocervical junction pathologies. According to the Harms technique, C1-C2 polyaxial screws are inserted respectively in the C1 lateral masses and in C2 pedicles. C1 lateral mass screw insertion requires the careful subperiosteal dissection of the posterior elements of C1, the identification of the screw entry point by the downward distraction of C2 nerve root, and the cautious sparing of the overlying posterior external vertebral venous plexus (peVVP), whose bleeding, obstructing the surgical field, is sometimes barely controlled by hemostatic agents and swabbing. The authors describe in detail the anatomical aspects of an alternative surgical technique developed for the microsurgical transposition of the C1-C2 interposed external vertebral venous plexus in the case of Harms C1-C2 screw stabilization. The longitudinal median incision of the atlantoaxial membrane, followed by bilateral subperiosteal dissection and microsurgical section respectively at the inferior borders of the C1 laminae and at the superior borders of the C2 laminae, allows, as a "window opening," the symmetrical mediolateral transposition of the peVVP. This procedure provides a faster and cleaner anatomical exposition of the posterior surface of the C1 lateral mass and the C2 isthmus, preventing troublesome intraoperative venous bleeding that hinders C1 lateral mass screw insertion.

Glomus Cervical Arteriovenous Malformation Presenting with Intracranial Subarachnoid Hemorrhage: Clinical Case and Pial Resection Surgical Technique Description.

Spinal intramedullary arteriovenous malformations (AVMs) can present with spinal hemorrhage. However, some of them occasionally can be the cause of angiographically negative intracranial subarachnoid hemorrhage, thus requiring a more comprehensive diagnostic approach to detect the possible source of bleeding. Nidal or arterial feeder aneurysms are widely considered high-risk rupture portions of the spinal AVM and recognized as a major cause of bleeding. Due to the tight eloquent confines within the thecal sac and the higher annual rupture risk after the initial bleeding, recurrent hemorrhage may have catastrophic outcomes. Hence the goal of management is to obliterate the spinal AVM preserving neurologic function and preventing future hemorrhagic events. Unlike cerebral AVMs, partial treatment of spinal intramedullary AVMs has been documented to be effective to improve the patients' prognosis dramatically. Microsurgical resection with or without adjuvant embolization has been considered the mainstay treatment for symptomatic glomus spinal intramedullary AVMs. The case of a 25-year-old man with acute cerebral subarachnoid hemorrhage caused by intranidal aneurysm rupture of cervical glomus-type AVM is presented here. The patient was surgically treated by C3-C4 laminectomy and AVM excision by pial resection technique. Thereby, the pial resection technique helps in providing subtotal AVM nidus resection, minimizing parenchymal dissection but effectively devascularizing glomus AVMs with satisfactory long-term results.

Reconstruction of vertebral body in thoracolumbar AO type A post-traumatic fractures by balloon kyphoplasty: a series of 85 patients with a long follow-up and review of the literature.

BACKGROUND: Traumatic fractures of the thoracolumbar spine are common injuries, accounting for approximately 90% of all spinal traumas. Optimal management of these fractures still gives rises to much debate in the literature. Currently, one of the treatment options in young patients with stable traumatic vertebral fractures is conservative treatment using braces. Kyphoplasty as a minimally invasive procedure has been shown to be effective in stabilizing vertebral body fractures, resulting in immediate pain relief and improving physical function with early return to work activity. The aim of our study was to report VAS, ODI scores, and kyphosis correction following treatment. METHODS: This is a retrospective study to investigate the clinical and radiological results 10 years after percutaneous balloon kyphoplasty followed by cement augmentation with polymethylmethacrylate (PMMA) or calcium phosphate cements (CPC), according to age, in 85 consecutive patients affected by 91 AO spine type A traumatic fractures of the thoracolumbar spine (A1, A2, and A3). Clinical follow-up was performed with the Visual Analogic Scale (VAS) at the preoperative visit and in the postoperative follow-up after 1 week, 1, 6, 12 months, and each year up to 10 years. Additionally, the Oswestry Disability Index (ODI) improvement was calculated as the difference between the ODI scores at the preoperative visit and at final follow-up. Finally, the Cobb angle from this cohort was assessed before surgery, immediately postoperatively, and at the end of follow-up. RESULTS: Kyphoplasty markedly improved pain and resulted in statistically significant vertebral height restoration and normalization of morphologic shape indexes that remained stable for at least 10 years following treatment. CONCLUSIONS: The present study showed that kyphoplasty and cement augmentation are an effective method of treatment for selected type A fractures.

Multidrug-resistant Gram-negative post-neurosurgical meningitis and the role of intraventricular colistin: a case series.

The aim of this study was to report the clinical experience of intraventricular colistin for the treatment of multi-resistant Gram-negative post-surgical meningitis in a tertiary hospital. Post-neurosurgical meningitis (PNM) is one of the life-threatening complications of neurosurgical procedures, and is frequently sustained by Acinetobacter baumannii and Klebsiella pneumoniae. Here we describe our experience of five cases of PNM caused by gram-negative multi-drug resistant (MDR) bacteria, treated with intraventricular (IVT) colistin, admitted to the Neurosurgery Unit of A.R.N.A.S. Civico of Palermo, Italy, from January 2016 to June 2020. In four patients the cerebrospinal fluid (CSF) culture was positive for A. baumannii, while in one patient it was positive for K. pneumoniae. IVT colistin therapy was administered for a median time of 18 days (range 7-29). The median time to CSF negativization was seven days (range 5-29). IVT colistin administration was associated with intravenous administration of meropenem and colistin in all patients. As regards clinical outcome, four patients were successfully treated and were subsequently discharged, while one patient died following respiratory complications and subsequent brain death. IVT colistin administration is an effective therapy for MDR post-neurosurgical meningitis and its administration is also prescribed by guidelines. However, IVT therapy for Gram-negative ventriculitis is mostly understudied. Our paper adds evidence for such treatment that can actually be considered life-saving.

Clinicopathologic Features of Thoracolumbar Interdural Disc Herniations: A Retrospective Case Series with a Systematic Literature Review.

BACKGROUND: Transdural disc herniations represent about 0.3% of all herniated discs. Preoperative imaging rarely demonstrates this condition. Therefore, diagnosis of transdural disc herniation is usually made intraoperatively. We describe the clinicopathologic features of extremely rare cases of thoracic and lumbar interdural disc herniations mimicking spinal intradural en plaque tumors. METHODS: This is a retrospective case series with a systematic literature review. Clinical presentation, imaging, differential diagnosis, intraoperative microsurgical findings, and possible pathogenesis were reviewed according to published guidelines. All patients underwent a posterior approach for microsurgical excision of disc herniation, but no epidural lesion was found. At intradural exploration, a tumor-like en plaque lesion was discovered. The surface of the lesion was incised, and multiple friable, cartilaginous white-yellow fragments were removed to achieve complete intralesional excision. RESULTS: The postoperative course was characterized by progressive neurologic improvement in all cases. In peculiar anatomic (adhesions between the anulus fibrosus, posterior longitudinal ligament, and ventral surface of dura mater) and pathologic (calcified giant disc herniation, spinal canal stenosis, previous lumbar spine surgery) conditions, penetration of disc fragment in the thickness of spinal dura mater can occur. CONCLUSIONS: Interdural disc herniations constitute a rare pathologic condition characterized by the migration of the herniated disc in neither the epidural nor the subdural spinal space, but rather in the thickness of the spinal dura mater. Further advances are necessary in neuroradiologic investigations to achieve a correct preoperative diagnosis, which is essential, as spine surgeons must be aware of these rare pathologies.

Percutaneous Endoscopic Transforaminal Outside-In Outside Technique for Foraminal and Extraforaminal Lumbar Disc Herniations-Operative Technique.

BACKGROUND: Different transforaminal endoscopic approaches have been developed for the surgical treatment of lumbar disc herniation: Kambin (intradiscal), Yeung (intraforaminal intradiscal), Ruetten (extreme lateral), transforaminal endoscopic surgical system (intraforaminal extradiscal) approach, and modifications. The operative technique for the treatment of foraminal and extraforaminal lumbar disc herniation through these surgical approaches has not been well described in reported studies. Moreover, each of these surgical approaches has limitations in the removal of migrated intra- or extraforaminal disc herniation. We have described, step by step, the operative technique of a modified percutaneous endoscopic transforaminal approach we have termed the "percutaneous endoscopic intra- and extraforaminal extradiscal approach or transforaminal outside-in outside [TOIO] approach" for the treatment of foraminal and extraforaminal lumbar disc herniation. METHODS: From 2012 to 2018, 48 patients had undergone the percutaneous endoscopic TOIO approach for symptomatic foraminal and extraforaminal lumbar disc herniation. The inclusion criteria were the same as the microdiscectomy criteria. The exclusion criteria included patients with severe foraminal stenosis and disc degeneration, listhesis, and scoliosis. The pre- and postoperative clinical data, radiographic findings, and surgical technique were investigated. RESULTS: No intraoperative complications developed. All the patients showed progressive improvement of initial neurological deficits with complete recovery of motor weakness and L4, L5 hypoesthesia at 1 month postoperatively. One patient experienced persistent postoperative dysesthesia on the affected leg for ∼1 month. CONCLUSION: The percutaneous endoscopic TOIO approach is a minimally invasive, safe, and efficacious surgical procedure for the treatment of lumbar foraminal and extraforaminal disc herniation. Proper patient selection is mandatory to ensure a satisfactory outcome.

Safety and Efficacy of Posterior Atlanto-Axial Stabilization Using Intraoperative Navigation System with Preoperative Computed Tomographic Scan.

BACKGROUND: Surgical approaches for posterior C1-C2 arthrodesis, such as C1-C2 transarticular and C1-C2 screw stabilization, are known to be demanding because of the anatomic close proximity of cervical vertebrae to neurovascular structures. Currently, navigation by fluoroscopy or intraoperative computed tomography (ICT) is the standard practice. However, fluoroscopy has various limitations, and ICT is time consuming and not available in many centers; furthermore, both diagnostic tools lead to exposure of the operating room staff to radiation exposure. We evaluate the safety, efficacy, and facility of a navigation system using only preoperative cervical computed tomography and computed tomographic angiography (CT/CTA), to prevent the risk of neurovascular damage in atlantoaxial stabilization. METHODS: The authors report a series of 21 patients who underwent posterior upper cervical spine fixation using a navigation system with intraoperative single-level vertebral registration on preoperative cervical CT/CTA (software BrainLab IPlan Spine 3.0). Intraoperative and postoperative comparative analysis was performed to verify the correspondence between the virtual anatomic position of the surgical instruments and screws represented on the neuronavigator, and the actual positions verified intraoperatively and on postoperative CT. RESULTS: Thirteen patients underwent C1-C2 arthrodesis with a Harms construct, 1 patient with transarticular screw fixation and 4 patients with occipitocervical stabilization. Three patients underwent C1-C2-C3 stabilization with C1 hooks, C2-C3 screws, and rod construct. On postoperative CT, the position of all screws appeared satisfactory. No neurovascular damage occurred in any patients. CONCLUSIONS: The use of a neuronavigation system, based on preoperative acquired cervical CT and intraoperative single-vertebra registration, may provide a valuable support for the improvement of the surgical accuracy of posterior C1-C2 screw fixation.

Skull Bone Defects Reconstruction with Custom-Made Titanium Graft shaped with Electron Beam Melting Technology: Preliminary Experience in a Series of Ten Patients.

BACKGROUND: Cranioplasty represents a challenge in neurosurgery. Its goal is not only plastic reconstruction of the skull but also to restore and preserve cranial function, to improve cerebral hemodynamics, and to provide mechanical protection of the neural structures. The ideal material for the reconstructive procedures and the surgical timing are still controversial. Many alloplastic materials are available for performing cranioplasty and among these, titanium still represents a widely proven and accepted choice. METHODS: The aim of our study was to present our preliminary experience with a "custom-made" cranioplasty, using electron beam melting (EBM) technology, in a series of ten patients. EBM is a new sintering method for shaping titanium powder directly in three-dimensional (3D) implants. FINDINGS: To the best of our knowledge this is the first report of a skull reconstruction performed by this technique. In a 1-year follow-up no postoperative complications have been observed and good clinical and esthetic outcomes were achieved. CONCLUSION: Costs higher than those for other types of titanium mesh, a longer production process, and the greater expertise needed for this technique are compensated by the achievement of most complex skull reconstructions with a shorter operative time.