Edward Fomekong

Intraoperative magnetic resonance imaging at 3-T using a dual independent operating room-magnetic resonance imaging suite: development, feasibility, safety, and preliminary experience.

OBJECTIVEA twin neurosurgical magnetic resonance imaging (MRI) suite with 3-T intraoperative MRI (iMRI) was developed to be available to neurosurgeons for iMRI and for independent use by radiologists. METHODSThe suite was designed with one area dedicated to neurosurgery and the other to performing MRI under surgical conditions (sterility and anesthesia). The operating table is motorized, enabling transfer of the patient into the MRI system. These two areas can function independently, allowing the MRI area to be used for nonsurgical cases. We report the findings from the first 21 patients to undergo scheduled neurosurgery with iMRI in this suite (average age, 51 ± 24 yr; intracranial tumor, 18 patients; epilepsy surgery, 3 patients). RESULTSTwenty-six iMRI examinations were performed, 3 immediately before surgical incision, 9 during surgery (operative field partially closed), and 14 immediately postsurgery (operative field fully closed but patient still anesthetized and draped). Minor technical dysfunctions prolonged 10 iMRI procedures; however, no serious iMRI-related incidents occurred. Twenty-three iMRI examinations took an average of 78 ± 20 minutes to perform. In three patients, iMRI led to further tumor resection because removable residual tumor was identified. Complete tumor resection was achieved in 15 of the 18 cases. CONCLUSIONThe layout of the new complex allows open access to the 3-T iMRI system except when it is in use under surgical conditions. Three patients benefited from the iMRI examination to achieve total resection. No permanent complications were observed. Therefore, the 3-T iMRI is feasible and appears to be a safe tool for intraoperative surgical planning and assessment.

Outcome of transsphenoidal surgery for Cushing's disease : A high remission rate in ACTH-secreting macroadenomas

OBJECTIVE Although numerous studies have shown that transsphenoidal surgery is the best initial treatment for Cushing disease offering 59-95% of success, fewer information is available on the long-term outcome in the subgroup of patients harboring ACTH-secreting macroadenomas. The aims of this study were to analyze our 10-year experience with transsphenoidal surgery in Cushings disease and to examine whether remission rates were different between micro- and macroadenomas. PATIENTS AND METHODS Forty consecutive patients with proven Cushings disease (28 microadenomas, 12 macroadenomas [diameter: 10-25 mm], 3 patients with no visible adenoma at MRI) underwent transsphenoidal surgery (TSS) assisted by neuronavigation in our center between 1996 and 2007. The diagnosis was made using standard endocrinological criteria including bilateral inferior petrosal sinus sampling (BIPSS) with CRH stimulation in all patients with discordant or equivocal biochemical and radiological testing. Morning serum cortisol was measured during the first week postoperatively, and a complete endocrine evaluation was made in all patients at 6-8 weeks. Remission at follow-up was defined as a normal postoperative 24-h urinary free cortisol (UFC) or continued need for glucocorticoid hormone replacement after TSS. RESULTS Overall, 32/40 patients (80%) were in remission after one or more TSS. Interestingly, a very good remission rate (92%) was observed in the subset of macroadenomas, similar to that found in the group of microadenomas (84%, NS), while no post-surgical remission was observed in the 3 patients with no visible adenoma at MRI (p<0.01). Of the 8 patients not in remission after repeated TSS surgery, 3 underwent radiation therapy and three had bilateral adrenalectomy, allowing remission of their hypercortisolism. There was minor morbidity and no death. CONCLUSION While our overall results are in accordance with other published series, we show here that ACTH-secreting pituitary macroadenomas are usually not associated with a bad outcome, in contrast with patients with no visible adenoma at preoperative MRI.

Pituitary stalk hemangioblastoma: The fourth case report and review of the literature

Supratentorial hemangioblastomas (HBL) have been rarely described in the literature. Herein we report the fourth case of pituitary stalk HBL diagnosed concurrently with cerebellar HBLs in a 51-year-old woman with von Hippel-Lindau disease. Complete resection of the lesion was achieved using left frontopterional craniotomy and no recurrence was observed after 8 years of follow-up. The clinical presentation, radiological features, pathological findings, and the management of this particular case are discussed in the light of the available literature. To our knowledge, this case is the only pituitary stalk HBL with total resection, and a long follow-up fully documented.

Percutaneous pedicle screw implantation for refractory low back pain: from manual 2D to fully robotic intraoperative 2D/3D fluoroscopy

Many surgical treatments for chronic low back pain that is refractory to medical treatments focus on spine stabilization. One of the main surgical procedures consists of placing an interbody cage with bone grafts associated with pedicle screws [2, 25, 30]. This technique can be performed using different approaches: a large open posterior approach, tubular approaches (minimal open) or percutaneously (minimally invasive percutaneous or MIP) [5, 28]. One of the main difficulties is to precisely locate the screws into the pedicle avoiding especially infero-medial pedicle breaches. This difficulty is even great- er when working percutaneously. This paper focuses on percutaneously placed pedicle screws (PPS), reports the use of a robotic multi-axis 2D/3D fluoros- copy to enhance the accuracy of pedicle screw placement and reviews other strategies and results reported in the literature.

Intraoperative 3T MRI for pituitary macroadenoma resection: Initial experience in 73 consecutive patients

OBJECTIVE To report a single-center experience with a 3T intraoperative magnetic resonance imaging (iMRI) to assess transsphenoidal microsurgery on pituitary macroadenomas. METHODS In a dual, independent operating room (OR) magnetic resonance imaging (MRI) suite, the operating table with the anesthetized patient was moved on rail tracks once a supposed maximized resection was reached to the MRI room for intraoperative image acquisition and interpretation. After the assessment of the iMRI images, the neurosurgeon evaluated whether additional resection was still possible. The resection rates were assessed on iMRI and postoperative MRI at 3 months. RESULTS A total of 73 macroadenomas benefited from an iMRI from March 2006 to October 2011. The gross total resection (GTR) rate at the time of the first iMRI was 58.9% (n=43). Based on the iMRI, eight patients (10.9%) underwent a second surgical resection. In 3 cases, the intraoperative imaging results were suspicious for a minor residue but not convincing enough for further surgery. Fortunately, the 3 months postoperative MRI control did not disclose any residual tumor in these cases. Finally, the GTR rate at the 3-month postoperative MRI increased to 72.6% (n=53). CONCLUSIONS 3T intraoperative MRI offered excellent quality images. Its use during transsphenoidal microsurgery on pituitary macroadenomas led to an increase not only in the extent of tumor resection (in 8 patients) but also in the rate of radical resections (69% instead of 60%). No complications due to the iMRI procedure were observed.

Intra-operative 3.0 T Magnetic Resonance Imaging Using a Dual-Independent Room: Long-Term Evaluation of Time-Cost, Problems, and Learning-Curve Effect

We present a short and comprehensive report of our 39-month experience using a 3.0 T intra-operative magnetic resonance imaging (ioMRI) neurosurgical-MR twin room, including a description of the problems encountered and the associated time-delays. Forty-seven problems were experienced during the 189 ioMRI procedures (two ioMRI were performed in five of the 184 surgical procedures) performed in the 39-month period, including a blocked transfer table, failure of anesthetic monitoring material, and specific MRI-related problems, such as head and coil positioning difficulties, artefacts, coil malfunctions and other technical difficulties. None of these problems prevented the ioMRI procedure from taking place or affected image interpretation, but they sometimes caused a significant delay. Fifteen (32%) of these problems occurred during the initial learning curve period. The mean duration of the ioMRI procedure was 75 min, which decreased slightly with experience, although an average waiting-for-access time of 24 min could not be avoided. These results illustrate that although performing ioMRI at 3.0 T with the dual room is a challenging procedure, it remains safe and feasible and associated with only minor dysfunctions while offering optimal image quality and standard surgical conditions.

Spine Navigation Based on 3-Dimensional Robotic Fluoroscopy for Accurate Percutaneous Pedicle Screw Placement: A Prospective Study of 66 Consecutive Cases

BACKGROUND Minimally invasive spine surgery is associated with obstructed visibility of anatomic landmarks and increased radiation exposure, leading to higher incidence of pedicle screw mispositioning. To address these drawbacks, intraoperative 3-dimensional fluoroscopy (io3DF) and navigation are being increasingly used. We aimed to present our dedicated multifunctional hybrid operating room (HyOR) setup and evaluate the accuracy and safety of io3DF image-guided spinal navigation in transforaminal lumbar interbody fusion with percutaneous pedicle screw (PPS) placement. METHODS The HyOR includes a fixed 3D multiaxis robotic fluoroscopy arm that moves automatically to the preprogrammed position when needed. An initial io3DF assessment is performed to collect intraoperative images, which are automatically transferred into the navigation system. These data are used to calibrate the PPSs and insert them under computer-assisted navigation. A second io3DF is performed for verifying PPS position. RESULTS Between January 2014 and December 2016, 66 consecutive patients (age, 58.6 ± 14.1 years) were treated for refractory lumbar degenerative pain. Seventy-three spinal levels were treated, and 276 screws were placed, with 4.2 ± 0.76 screws per patient. There was no measurable radiation to the HyOR staff, whereas the mean radiation dose per patient was 378.3 μGym2. The overall accuracy rate of PPS placement was 99.6%. There were no significant procedure-related complications. CONCLUSIONS Spine navigation based on io3DF images enabled us to avoid radiation exposure to the operating room team while delivering minimal but sufficient radiation doses to our patients. This approach achieved an accuracy rate of 99.6% for PPS placement in the safe zone, without significant complications.

Unusual association between lysinuric protein intolerance and moyamoya vasculopathy

INTRODUCTION Lysinuric protein intolerance (LPI) is a form of inherited aminoaciduria caused by a deficiency in the cationic amino acid transport process on the basolateral membrane of enterocytes and renal tubular cells. Clinical signs include gastrointestinal symptoms, failure to thrive, hepatosplenomegaly, osteoporosis, episodes of coma, intellectual deficiency, lung and renal involvement, bone marrow abnormalities, as well as altered immune response. Moyamoya disease is a cerebrovascular disorder predisposing sufferers to stroke through progressive stenosis of the intracranial internal carotid arteries and their proximal branches. Patients with characteristic moyamoya vasculopathy who also exhibit well-recognized associated conditions, such as Down syndrome or sickle-cell disease, are diagnosed with moyamoya syndrome, whereas those with no known associated risk factors are said to suffer from moyamoya disease. CASE STUDY A 5-year-old girl exhibiting aversion to protein-rich food and splenomegaly presented with a history of recurrent ischemic strokes. Cerebral angiography confirmed moyamoya vasculopathy. Metabolic investigation revealed abnormalities characteristic of LPI. This diagnosis was confirmed by the detection of a mutation within the SLC7A7 gene upon molecular investigation. CONCLUSION To the best of our knowledge, this is the first reported case of an association between moyamoya vasculopathy and LPI. While the question of association or coincidence cannot yet be answered, several pathophysiological consequences of LPI can be defined as separate, such as links between the impact of low arginine levels on the function of vascular endothelium and brain nitric oxide metabolism, as well as hemophagocytic syndrome associated with the risk of vasculitis, thus accounting for the development of moyamoya vasculopathy.

Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS) of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications.

Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report.

BACKGROUND AND IMPORTANCE Skull base spontaneous cerebrospinal fluid fistulas have been recently recognized as secondary to pseudotumor cerebri. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected. Regardless of their etiology, the clinical manifestation of skull base fistulas is usually the same and includes a rhinorrhea and less frequently an otorrhea. We report a case of a cryptic sphenoid cerebrospinal fluid fistula discovered intraoperatively during the excision of a pituitary ACTH-secreting microadenoma (2mm in diameter). CLINICAL PRESENTATION A 54-year-old female was admitted to our neurosurgery department for Cushings disease due to a pituitary microadenoma. Six months prior to admission, she complained of severe fatigue, polyphagia and weight gain. Clinical examination revealed central obesity with a body mass index of 45kg/m(2) and other symptoms suggestive of Cushings disease. Hormonal tests and a MR scan revealed a pituitary ACTH-secreting microadenoma. During the operative procedure via a transnasal approach, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out cerebrospinal fluid under pressure without interruption. The microadenoma was macroscopically completely removed without any cerebrospinal fluid coming from the pituitary surgical cavity. The closing procedure of the sphenoid groove millimetric opening was performed by injecting fibrin glue and a lumbar drain was placed indwelling for four days. CONCLUSION This case report describes a cryptic sphenoid submucosal cerebrospinal fluid fistula in a patient with Cushings syndrome. This type of case raises the question of the natural evolution of the skull base cerebrospinal fluid fistula from its formation to an externalization such as rhinorrhea.