AN EXTENDED FOLLOW-UP OF SPINAL INSTRUMENTATION RESCUE WITH CEMENT AUGMENTATION.

BACKGROUND AND PURPOSE: Percutaneous cement augmentation has been reported as an effective salvage procedure for frail patients suffering with spinal instrumentation failure, such as screw loosening, hardware breakage, cage subsidence, and fractures within or adjacent to stabilized segments. Favorable results were reported over a median follow-up period of 16 months in a retrospective analysis of 31 consecutive procedures performed in 29 patients. In the present study, the long-term effectiveness of this treatment in avoiding or postponing revision surgery is reported. MATERIALS AND METHODS: Clinical and radiological data of our original cohort of patients were retrospectively collected and reviewed to provide an extended follow-up assessment. The need for revision spinal surgery was assessed as the primary outcome and the radiological stability of the augmented spinal implants was considered as the secondary outcome. RESULTS: An extended radiological follow-up was available in 27/29 patients with an average of 50.9 months. Overall, 18/27 (66.7%) patients, originally candidates for revision surgery, avoided a surgical intervention after a cement augmentation rescue procedure. In the remaining patients, the average interval between the rescue cement augmentation and the revision surgery was 22.5 months. Implant mobilization occurred in 2/27 (7.4%) patients, rod breakage in 1/27 (3.7%), a new fracture within or adjacent to the instrumented segment occurred in 4/27 (14.8%) patients and screw loosening at rescued levels occurred in 5/27 (18.5%) patients. CONCLUSIONS: In this cohort, cement augmentation rescue procedures were found to be effective in avoiding or postponing revision surgery during long-term follow up. ABBREVIATIONS: N/A.

Improving workflows of neuro-interventional procedures with autostereoscopic 3D visualization of multi-modality imaging in hybrid interventional suites.

PURPOSE: Recent developments in interventional neuroradiology techniques, medical imaging modalities, endovascular stenting and embolization materials lead to an increasing number of patients with cerebral aneurysms and arteriovenous malformations that are eligible for endovascular treatment and have opened new perspectives for novel ways for patient treatment in general. In this paper, we describe a software tool for 3D image fusion of multi-modal acquisitions to assist endovascular treatment of cerebral malformations. The software and an autostereoscopic 3D display were implemented and tested in clinical applications in a hybrid interventional suite that is used for radio-interventional as well as neurosurgical procedures. Our hypothesis is that fusion of image data acquired prior to intervention procedures with images acquired during those procedures should allow better visualizing and navigating through complex cerebral vasculature. This should also improve workflows of neuro-interventional procedures. METHODS: Preoperative and intra-operative acquisitions of vascular images of the brain were performed and transferred to a dedicated imaging workstation to be processed with our image fusion and visualization software tool. The tool was developed as a plugin extension to the open-source DICOM viewer OsiriX and is based on a modular and scalable architecture. Several processing modules were implemented to allow spatial co-registration and fusion of preoperative and intra-operative modalities. A special extension was also implemented for interactive autostereosopic, glass-free 3D visualization of fused results. RESULTS: The software platform was validated and evaluated in nine in vivo procedures by expert users. All patient cases were related to interventional treatment of neuro-vascular diseases. The emphasis was laid on the added value of spatial co-registration and fusion of preoperative and intra-operative modalities, as well as the overall impact on workflow during the intervention. The co-registered and fused images were visualized on an autostereoscopic 3D monitor installed in hybrid interventional suite. All experiments were evaluated and scored by interventional physicians and technicians. CONCLUSIONS: Displaying 3D-4D representations of brain vascular anomalies based on multi-modal acquisitions on a 3D autostereoscopic display is beneficial for the workflow and efficiency of interventional radiologists. The implemented software tool fulfills the premise of applicability of an open-source platform for more advanced, multi-modal visualization and processing of brain vascular structures for image-guided therapeutic interventions.

Augmented reality-assisted skull base surgery.

Neuronavigation is widely considered as a valuable tool during skull base surgery. Advances in neuronavigation technology, with the integration of augmented reality, present advantages over traditional point-based neuronavigation. However, this development has not yet made its way into routine surgical practice, possibly due to a lack of acquaintance with these systems. In this report, we illustrate the usefulness and easy application of augmented reality-based neuronavigation through a case example of a patient with a clivus chordoma. We also demonstrate how augmented reality can help throughout all phases of a skull base procedure, from the verification of neuronavigation accuracy to intraoperative image-guidance.

[Hybrid operation theatre from the perspective of neurosurgery]. / Hybridoperationssaal aus Sicht der Neurochirurgie.

BACKGROUND: The integration of hybrid operation theatre into neurosurgical and neuroradiological routines is revolutionizing in particular the management of neurovascular emergencies, such as subarachnoid aneurysmal hemorrhage (SAH) or ruptured arteriovenous malformations. RESULTS: The direct interaction between neurosurgeons and neuroradiologists in a joint environment changes and accelerates all diagnostic and therapeutic steps because all relevant procedures, including treatment control can be performed in a single room. Interventions of the skull base or the spine are also a domain of such hybrid theatre. CONCLUSION: As this new concept requires organisational changes throughout the entire patient management, a change of mindset is also needed at the institutional level in order to attain maximum benefits from such a setting.

Renal carcinoma relapse presenting as a peripheral nerve sheath tumor: A case report and brief review of the literature.

We report a rare case of renal carcinoma metastasis involving a lumbar nerve root. Metastases to nerve roots are rare occurrences, and to our knowledge, only six cases have been reported so far in the literature. The patient in this report presented with weakness in the right lower limb and intractable pain irradiating along the L5 dermatome. MRI findings revealed a right-sided L5 nerve root mass, suggestive of a schwannoma, involving the spinal ganglion and its extraforaminal region. Complete macroscopic resection of this mass was performed, and histopathologic analysis confirmed the lesion to be a metastasis of a renal clear cell carcinoma. Local radiotherapy was given and tyrosine kinase inhibitors administered. At 5 months, the patient was pain-free and his right limb weakness had completely resolved. A tumoral recurrence could be observed on the control MRI 5 months after surgery. This report presents the first case of a patient with a renal clear cell carcinoma metastasis to a L5 nerve root, as well as a brief review of previous cases of metastases to peripheral nerve roots.