Daniel Felbaum

The rising psoas sign: an analysis of preoperative imaging characteristics of aborted minimally invasive lateral interbody fusions at L4-5

Minimally invasive lateral interbody fusion for the treatment of degenerative disc disease, spondylolisthesis, or scoliosis is becoming increasingly popular. The approach at L4-5 carries the highest risk of nerve injury given the proximity of the lumbar plexus and femoral nerve. The authors present 3 cases that were aborted during the approach because of pervasive electromyography responses throughout the L4-5 disc space. Preoperative imaging characteristics of psoas muscle anatomy in all 3 cases are analyzed and discussed. In all cases, the psoas muscle on axial views was rising away from the vertebral column as opposed to its typical location lateral to it. Preoperative evaluation of psoas muscle anatomy is important. A rising psoas muscle at L4-5 on axial imaging may complicate a lateral approach.

Bilateral Subaxial Rotational Vertebral Artery Occlusion in a Setting of a Prior Cervical Construct

BACKGROUND Rotational vertebral artery occlusion, or bow hunters syndrome, most commonly affects the C1-2 level because of its importance in regulating rotational movement. CASE DESCRIPTION A 50-year-old man with increasing neck pain and severe symptoms of vertebrobasilar insufficiency with bidirectional head rotation had undergone several prior subaxial cervical spine operations. Dynamic cerebral angiography demonstrated complete occlusion of the left vertebral artery during head rotation to the right and complete occlusion of the right vertebral artery during head rotation to the left. Occlusions occurred at the level of and rostral to his prior construct, with immediate recurrence of debilitating vertigo and near syncope. Successful radiographic and clinical resolution of symptoms was achieved by posterior instrumentation and fusion from C2, connecting to his prior hardware. CONCLUSIONS A brief literature review and treatment options are discussed for this unusual presentation of a rare clinical entity.

Endoscope-Assisted Combined Supracerebellar Infratentorial and Endoscopic Transventricular Approach to the Pineal Region: A Technical Note.

Neoplasms of the pineal region comprise less than 2% of all intracranial lesions. A variety of techniques have been adapted to gain access to the pineal region. Classic approaches employ the use of the microscope. More recently, the endoscope has been utilized to improve access to such deep-seated lesions. A 62-year-old female presented with a heterogeneously enhancing lesion in the pineal region with associated hydrocephalus. On exam, the patient exhibited Parinaud’s syndrome. The patient initially underwent a single burr hole endoscopic third ventriculostomy and biopsy of the lesion. Initial pathology was consistent with a grade III astrocytoma. Following a period of recuperation, she returned for definitive surgical resection. A suboccipital craniectomy was performed in the sitting position. Prior to dural opening, an endoscope was inserted into the right lateral ventricle through the prior burr hole.The endoscope was passed through the foramen of Monro and the tumor could be visualized along the posterior third ventricle. The patient underwent a standard supracerebellar infratentorial approach aided by the microscope. After initial debulking of the pineal lesion, an endoscope was utilized to guide the depth of resection and assist in dissection with transventricular manipulation of the tumor. During the final stages of resection from the craniotomy, the endoscope was used to help visualize the posterior supracerebellar corridor. This assisted in the assessment of the extent of resection. The endoscope was also utilized for the removal of intraventricular blood products following tumor resection. The patient was extubated and transferred to the intensive care unit. A postoperative contrast-enhanced magnetic resonance imaging (MRI) revealed greater than 95% resection, with expected residual within the midbrain. The combined supracerebellar infratentorial and transventricular endoscope-assisted approach provided maximum visualization and aided in optimal resection of a traditionally difficult pineal region tumor. Further experience with this combined technique may allow for improved surgical outcomes for these complex lesions.

Mobile Schwannoma of the Lumbar Spine: A Case Report and Review of the Literature.

Mobile schwannomas of the spine have been sparsely documented in the literature. In cases referred to in existing literature, the migratory schwannoma was documented to occur in the lumbar spine. We added another case to the small available literature. In our case report, the patient had a previously known lumbar schwannoma that was being managed conservatively. Due to an acute change in clinical symptoms, repeat imaging was performed. A magnetic resonance imaging (MRI) of his spine revealed migration of the schwannoma two levels rostral to his recent imaging from six weeks earlier. The patient underwent surgical resection of his lesion. During the operation, the ultrasound was utilized to confirm the lesion prior to dural opening. In this report, we attempt to provide further evidence of the utility of an intraoperative ultrasound for intradural lesions and intend to add to the published literature of mobile schwannomas of the spine

Awake Craniotomy for the Treatment of a Cortical Pseudoaneurysm in a Pregnant Patient

Neurosurgical pathologies presenting during pregnancy are uncommon. If present, the situation creates a unique diagnostic, observational, and therapeutic challenge as both lives are placed at potential risk. Surgical procedures during pregnancy are approached carefully as physiological stressors associated with surgery and anesthesia may cause fetal or maternal compromise. We present the only known case of a pseudoaneurysm treated with an awake craniotomy, allowing us to abate the risks associated with general anesthesia in pregnancy. A female suffered a superficially penetrating gunshot wound to the head for which she underwent a craniotomy with complete neurological recovery. She had complaints of intermittent headaches, dizziness, and tingling of her hands five months thereafter. The cerebral angiogram demonstrated an 8 mm pseudoaneurysm under her craniotomy site. A surgical repair of this aneurysm was undertaken in the 23rd week of pregnancy via an awake craniotomy with regional scalp block. The aneurysm was resected without complication, and the patient tolerated the procedure without neurological deficit during or subsequent to the operation. Cerebrovascular pathology in pregnant patients remains a difficult situation that poses challenges associated with the pathology itself as well as the anesthetic implications inherent with operative management. The neurosurgical literature demonstrates that surgical management of cerebrovascular pathology is well-tolerated in pregnancy, and our case further demonstrates the capability of utilizing an awake craniotomy for the treatment of this type of lesion without causing a residual deficit.

Percutaneous Lumbar Transfacet Screw Fixation: A Technique Analysis of 176 Screws in 83 Patients With Assessment of Radiographic Accuracy, Hardware Failure, and Complications

BACKGROUND: Transfacet screw fixation can be used to supplement varying techniques of lumbar interbody fusion. The percutaneous placement of transfacet screws represents an alternative to pedicle screws for select cases, which can potentially minimize morbidity. OBJECTIVE: To analyze our experience with respect to accuracy, hardware failure, and neurologic compromise. METHODS: Clinical records gathered from August 2009 to January 2014 were retrospectively reviewed. We identified 83 patients who underwent placement of 176 consecutive percutaneous transfacet screws while in the prone or lateral position. Accuracy of screw placement was assessed on computed tomography (CT) by entry point and end point. Hardware failure was assessed by radiography or CT. Clinical complications were assessed during regular follow-up visits. RESULTS: Entry point accuracy was 91.4%. Seven cases of intra-articular screw placement and 1 para-articular screw placement were detected on CT. End-point accuracy was 82.8%. There were 16 cases of pedicle breach from 1 to 3 mm on CT. There were 2 screw fractures and 1 case of a Kirschner-wire fracture that were clinically inconsequential. One patient had new nondisabling leg numbness. One patient with new radicular leg pain required removal of a screw. CONCLUSION: The technique of percutaneous lumbar transfacet screw fixation can be performed accurately and safely with patients in the prone and lateral positions. Entry point inaccuracies were more common at rostral levels due to facet orientation. End-point inaccuracies (pedicle breaches) were more common in the intervertebral foramen where 2 clinical complications occurred. ABBREVIATIONS: ALIF, anterior lumbar interbody fusion AP, anteroposterior K-wire, Kirschner wire LLIF, lateral lumbar interbody fusion TLIF, transforaminal lumbar interbody fusion TTS, transfacet transpedicular screw

Simultaneous Transventricular-Orbitocranial Resection of Large Suprasellar Craniopharyngioma as Inspired by Jackson's Maneuver from 1863

Traditional skull base techniques utilizing the microscope have allowed surgeons improved safe access to deep-seated lesions. More recent technical advances with the endoscope have allowed improved visibility and access to these previously difficult-to-reach regions. Most current literature emphasizes one technique over the other. We present a unique hybrid-type approach that tackles this not-infrequent surgical dilemma. This hybrid-type surgery resulted in a new technique that is a confluence of both open microsurgery and skull base corridors with an endoscope. Furthermore, a combined ventriculoscope approach adds extended assistance with resection. We detail the utility of this technique. A patient presented with a large suprasellar lesion that was suspicious for a craniopharyngioma. Given improved survival with extent of resection, the goal of surgical intervention was maximal safe resection. The location of the tumor would have involved certain morbidity with deliberate residual if a skull base approach or endoscope-based approach was employed independently. As a result, the patient underwent a hybrid-type operation using a multi-corridor split-surgical team approach for the resection of her tumor. The patient underwent hybrid surgery via a combined open microsurgical craniotomy, endoscopic resection, and a ventriculoscope-assisted approach. The ventriculoscope access allowed for resection of the intraventricular portion of the tumor and guided the extent of resection from the microsurgical corridor. Additionally, from a separate craniotomy, the suprasellar component was resected using both standard skull base and endoscope-assisted techniques. The patient tolerated the procedure well without additional morbidity provided from the multi-corridor hybrid technique. The hybrid surgery resulted in a new multi-modality, split-surgical team approach providing maximal visualization with minimal added morbidity to resect a lesion difficult to access. This hybrid technique may be an effective piece of the surgeon’s armamentarium to provide improved patient outcomes.

Real-Time Evaluation of Anterior Choroidal Artery Patency During Aneurysm Clipping

Inadvertent occlusion of the anterior choroidal artery during aneurysm clipping can cause a disabling stroke in minutes. We evaluate the clinical utility of direct cortical motor evoked potential (MEP) monitoring during aneurysm clipping, as a real-time assessment of arterial patency, prior to performing indocyanine green videoangiography. Direct cortical MEPs were recorded in seven patients undergoing surgery for aneurysms that involved or abutted the anterior choroidal artery. The aneurysms clipped in those seven patients included four anterior choroidal artery aneurysms and six posterior communicating artery aneurysms. Serial MEP recordings were performed during the intradural dissection, aneurysm exposure, and clip placement. A significant change in MEPs after clip placement would prompt immediate inspection and removal or repositioning of the clip. If the clip placement appeared satisfactory and MEP recordings were stable, then an intraoperative indocyanine green videoangiogram was performed to confirm obliteration of the aneurysm and patency of the arteries. Seven patients underwent successful clipping of anterior choroidal artery aneurysms and posterior communicating artery aneurysms using direct cortical MEP monitoring, with good clinical and radiographic outcomes. In six patients, no changes in MEP amplitudes were observed following permanent clip placement. In one patient, a profound decrease in MEP amplitude occurred 220 seconds after placement of a permanent clip on a large posterior communicating aneurysm. An inspection revealed that the anterior choroidal artery was kinked. The clip was immediately removed, and the MEP signals returned to baseline shortly thereafter. A clip was then optimally placed, and the patient awoke without neurologic deficit. Direct cortical MEPs are a useful adjunct to standard electrophysiologic monitoring in aneurysm surgery, particularly when the anterior choroidal artery or lenticulostriate arteries are at risk. When these arteries are occluded, infarction may occur before the occlusion is detected by indocyanine green videoangiography or intraoperative angiography. The use of MEPs allows real-time detection of ischemia to subcortical motor pathways.

Vertebral-venous fistula: an unusual cause for ocular symptoms mimicking a carotid cavernous fistula.

Vertebral–venous fistulas (VVF), or vertebral–vertebral arteriovenous fistulas, are an uncommon clinical entity. Typically, they present as a result of a direct vascular connection between an extracranial branch of the vertebral artery or its radicular components and the epidural venous plexus. These may manifest with signs and symptoms referable to cervical myelopathy secondary to compression or steal phenomenon. To our knowledge, this is the first case to identify a patient who presented with classic ocular symptoms attributable to a carotid cavernous fistula but secondary to a VVF. We present its treatment and clinical outcome. In addition, we present a brief literature review surrounding this uncommon disease.

Carotid Stenosis: Utility of Diagnostic Angiography

OBJECTIVE Carotid artery stenosis is frequently diagnosed through screening tests with noninvasive imaging. Because of differences noted between the various modalities, we sought to investigate our experience comparing noninvasive imaging (ultrasound, computed tomography angiography, magnetic resonance angiography) with invasive imaging (digital subtraction angiography). METHODS In a multicenter retrospective analysis, 249 carotid vessels were reviewed based on angiography with the associated noninvasive imaging. RESULTS Overall, medical or surgical decision management was changed in 43% (107/243) of cases investigated with digital subtraction angiography owing to a discrepancy between the measured percentage stenosis. In patients with potentially treatable carotid stenosis, angiography revealed nonsignificant stenosis 25.7% of the time. CONCLUSIONS Angiography should be considered the confirmatory test for degree of stenosis in certain patients before definitive surgical treatment.