Randall J. Hlubek

First human implantation of a bioresorbable polymer scaffold for acute traumatic spinal cord injury: A clinical pilot study for safety and feasibility

BACKGROUND AND IMPORTANCE A porous bioresorbable polymer scaffold has previously been tested in preclinical animal models of spinal cord contusion injury to promote appositional healing, spare white matter, decrease posttraumatic cysts, and normalize intraparenchymal tissue pressure. This is the first report of its human implantation in a spinal cord injury patient during a pilot study testing the safety and feasibility of this technique (ClinicalTrials.gov Identifier: NCT02138110). CLINICAL PRESENTATION A 25-year-old man had a T11-12 fracture dislocation sustained in a motocross accident that resulted in a T11 American Spinal Injury Association Impairment Scale (AIS) grade A traumatic spinal cord injury. He was treated with acute surgical decompression and spinal fixation with fusion, and enrolled in the spinal scaffold study. A 2 × 10 mm bioresorbable scaffold was placed in the spinal cord parenchyma at T12. The scaffold was implanted directly into the traumatic cavity within the spinal cord through a dorsal root entry zone myelotomy at the caudal extent of the contused area. By 3 months, his neurological examination improved to an L1 AIS grade C incomplete injury. At 6-month postoperative follow-up, there were no procedural complications or apparent safety issues related to the scaffold implantation. CONCLUSION Although longer-term follow-up and investigation are required, this case demonstrates that a polymer scaffold can be safely implanted into an acutely contused spinal cord. This is the first human surgical implantation, and future outcomes of other patients in this clinical trial will better elucidate the safety and possible efficacy profile of the scaffold. ABBREVIATIONS AIS, American Spinal Injury Association Impairment ScaleSCI, spinal cord injurytSCI, traumatic spinal cord injury.

Use of Intracranial Pressure Monitoring Frequently Refutes Diagnosis of Idiopathic Intracranial Hypertension

BACKGROUND The diagnosis and management of patients with idiopathic intracranial hypertension (IIH) frequently relies on lumbar puncture to ascertain intracranial pressure (ICP). However, ICP values derived this way may be spurious owing to patient body habitus and behavior. We recently incorporated direct continuous ICP monitoring into the work-up for IIH. METHODS Through billing records, we identified all patients during a 3-year period who had a diagnosis of IIH and who underwent ICP monitoring before shunt placement or revision. Patient demographics and clinical data were reviewed. RESULTS Of 30 patients who underwent ICP monitoring with an intraparenchymal wire, 17 had undergone lumbar puncture within the previous 6 months. Results from lumbar punctures showed an elevated opening pressure in all 17 patients, whereas only 2 patients (12%) were found to have consistently elevated ICP with direct ICP monitoring. Of 15 patients being evaluated for shunting, 4 (27%) were found to have elevated ICP. Of the 15 patients with existing shunts, 2 patients (13%) were found to have malfunctioning shunts after pressure monitoring, and 3 patients (20%) had shunts that were found to be unnecessary and were removed. No patient experienced any complication from invasive monitoring. CONCLUSIONS Direct ICP monitoring is the gold standard for determining ICP and can be safely and effectively applied to the work-up and treatment of patients with IIH to reduce the occurrence of misdiagnosis and unnecessary surgery.

Divergent Bilateral Posterior Lumbar Interbody Fusion with Cortical Screw Fixation: Description of New Trajectory for Interbody Technique from Midline Exposure

BACKGROUND A major drawback to use of cortical bone trajectory pedicle screws (CBTPSs) with traditional posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion grafts is that traditional graft insertion trajectories require wider posterior exposure. This wider exposure, beyond the limits otherwise required for CBTPS placement, negates a primary benefit of CBTPS fixation. The aim of this study was to define an alternative surgical technique for interbody graft placement that, when used in conjunction with CBTPS fixation, permits both minimal soft tissue dissection and optimal graft placement. METHODS A team of neurosurgeons specializing in treatment of spinal pathologies developed a surgical technique for insertion of bilateral PLIF grafts that complements the principles of CBTPS fixation. This technique is illustrated in a patient undergoing lumbosacral decompression, CBTPS fixation, and 3-column arthrodesis. RESULTS The described technique uses a divergent trajectory of bilateral PLIF grafts rather than the traditional parallel or convergent trajectories. CONCLUSIONS By aiming medially to laterally with the interbody graft, one recapitulates many advantages of CBTPSs, including avoidance of wide tissue dissection, greater intergraft volume available for bone grafting, and greater graft coverage of the hypophyseal ring. The prospective collection of outcome data for patients who undergo lumbosacral fusion using the divergent PLIF technique is ongoing.

Novel Surgical Treatment Strategies for Unstable Lumbar Osteodiscitis: A 3-Patient Case Series

BACKGROUND Lumbar osteomyelitis frequently affects patients with medical comorbidities and poor preoperative health. Surgery is indicated when medical management fails or patients present with spinal instability or neural compromise. Successful arthrodesis can be difficult and sometimes requires alternative surgical techniques. OBJECTIVE To report 3 novel methods, each illustrated by a case, for achieving arthrodesis for lumbar osteomyelitis. METHODS A retrospective review was performed of 3 cases of surgical treatment of lumbar osteomyelitis. Novel aspects of the surgical techniques are reported, as are perioperative clinical details and imaging results. RESULTS In the first patient, a vascularized iliac crest graft on a quadratus lumborum pedicle was rotated into the posterolateral fusion bed of the affected level. In the second, an anterior approach with debridement of affected lumbar levels was followed by rotation of a vascularized iliac crest graft on an iliacus muscle pedicle into the anterior lumbar defect. In the third, a structural, nonvascularized iliac crest graft was harvested via a lateral approach to provide better surgical access, and an autologous tricortical bone graft was obtained for placement in the debridement defect. Follow-up imaging suggested successful early incorporation of all the grafts in the fusion beds. CONCLUSION Patients with multiple risk factors for pseudarthrosis and recurrent infection often require alternative surgical strategies to augment fusion. These 3 novel methods for lumbar debridement, fixation, and fusion using vascularized or nonvascularized autograft accommodate posterior, anterior, and lateral surgical approaches. Further experience with these techniques is required to compare outcomes with those of traditional techniques.

Operative Management of Idiopathic Spinal Cord Herniation: Case Series and Novel Technique for Repair of Recurrent Herniation

BACKGROUND Idiopathic spinal cord herniation (ISCH) is a rare pathology of the spine defined by herniation of the spinal cord through a dural defect. OBJECTIVE To highlight the operative management of ISCH and the surgical nuances of ISCH repairs conducted at our institution. METHODS This retrospective review examines consecutive patients with ISCH who were treated surgically between January 1, 2010, and July 31, 2017, at Barrow Neurological Institute, Phoenix, Arizona. RESULTS Four patients with ISCH presented with thoracic myelopathy and lower extremity weakness during the study period. Treatment consisted of reduction of the herniated spinal cord and filling of the dural defect with a collagen-based dural regeneration matrix. In 3 patients the dural edges were covered with a collagen-matrix intradural sling, and in 1 patient they were repaired primarily with interrupted sutures. Three of the 4 patients experienced improvement in myelopathic symptoms; the fourth patient suffered neurological decline in the immediate postoperative period. CONCLUSION ISCH is a complex pathological condition likely to result in progressive myelopathy. Surgery offers patients the possibility of stabilizing the progression of the spinal cord dysfunction and perhaps restoring neurological function. However, extreme care must be taken during surgery to minimize manipulation of the fragile herniated cord.

Posterior Reversible Encephalopathic Syndrome in the Setting of Induced Elevated Mean Arterial Pressure in Patients With Spinal Cord Injury

BACKGROUND AND IMPORTANCE Acute spinal cord injury (SCI) is managed by avoiding hypotension and elevating mean arterial pressure (MAP) to attain optimal perfusion of the spinal cord. Few studies have been published regarding complications related to this treatment paradigm. CLINICAL PRESENTATION Three patients with SCI developed posterior reversible encephalopathic syndrome (PRES) during treatment with intravenous fluids and vasopressors administered to maintain elevated MAPs. All of them experienced temporary elevations well above the standard blood pressure goals for acute SCI and deterioration of neurological status. CONCLUSION PRES is a potential complication of elevated MAPs in patients with SCI, particularly if the blood pressure rises above the goals of standard treatment paradigms. The neurosurgical staff should be suspicious of possible PRES early in the course of acute SCI in patients with unexplained neurological decline. This case series is the first report of PRES in patients with acute SCI.

Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy for the Treatment of Hypothalamic Hamartomas: A Retrospective Review

BACKGROUND Hypothalamic hamartomas (HH) are rare lesions associated with treatment-resistant epilepsy. Open surgery results in modest seizure control (about 50%) but has a significant associated morbidity. Radiosurgery is limited to a subset of patients due to latent therapeutic effects. Magnetic resonance imaging-guided laser interstitial thermal therapy (LITT) offers a novel minimally invasive option. OBJECTIVE To evaluate a single centers outcomes for the LITT treatment of HH. METHODS We retrospectively reviewed our experience with LITT for the treatment of HH using our institutions prospectively maintained patient database. RESULTS Eighteen patients (mean age, 21.1 yr; median age, 11 yr) underwent 21 total LITT treatments for HH. Mean follow-up was 17.4 mo. The length of stay was 1 night for 16 (89%) patients. At the end of follow-up, 11 of 18 patients (61%) had full disconnection of the HH, and 12 of 15 (80%) patients with gelastic seizures and 5 (56%) of 9 patients with nongelastic seizures were seizure free (International League Against Epilepsy Class 1). Immediate complications included a 39% (7/18) incidence of neurological deficits, including 1 case of hemiparesis. At the end of follow-up, 22% of patients (4/18) had persistent deficits. The hypothyroidism that occurred was delayed in 11% of patients (2/18), as was short-term memory loss (22%, 4/18) and weight gain (22%, 4/18). CONCLUSION LITT therapy for HH can achieve excellent rates of seizure control with low morbidity and a short postoperative stay in a majority of patients. Additional research is needed to assess the durability of results and the full spectrum of cognitive outcomes.

Safety and accuracy of freehand versus navigated C2 pars or pedicle screw placement

BACKGROUND CONTEXT C2 pedicle and pars screws require accurate placement to avoid injury to nearby neurovascular structures. Freehand, fluoroscopically guided, and computed tomography (CT)-based navigation techniques have been described in the medical literature. PURPOSE The present study aims to compare the safety and accuracy of the freehand technique versus stereotactic navigation for the placement of C2 pedicle and pars screws. STUDY DESIGN/SETTING This study was a retrospective review of consecutive patients treated with posterior fixation constructs. PATIENT SAMPLE A total of 220 consecutive patients were treated with posterior fixation constructs containing C2 pars or pedicle screws placed at our institution. OUTCOME MEASURES Computed tomography imaging was used to assess the accuracy of screw placement. Intraoperative complications and incidence of stroke or mortality within 30 days of the operation were analyzed. METHODS A retrospective review was conducted of consecutive patients treated with posterior fixation constructs containing C2 pars or pedicle screws placed by spine surgeons between January 1, 2010, and August 31, 2016. Clinical and radiographic data were collected and analyzed. Screw accuracy was graded independently by two reviewers according to the following criteria: grade A (no breach), grades B-E (breach with transverse foramen obstruction of 1%-25%, 26%-50%, 51%-75%, or 76%-100%, respectively), and grade M (medial breach). Screws were divided into acceptable (grades A and B) and unacceptable (grades C-E and M). RESULTS A total of 426 C2 pars or pedicle screws (312 freehand, 114 navigated) were placed in 220 patients (160 freehand, 60 navigated). Complications were similar between the groups: three vertebral artery injuries (two [1%] freehand, one [2%] navigated; p>.99), five deaths (four [3%] freehand, one [2%] navigated; p>.99), and one (2%) stroke in the navigated group (p=.61). Computed tomography imaging was available for accuracy grading of 182 screws (131 freehand, 51 navigated). No breaches (grade A) occurred in 113 of the freehand screws (86%) and in 34 of the navigated screws (67%) (p=.006). More screws had acceptable placement in the freehand group (123 of 131, 94%) than in the navigated group (42 of 51, 82%) (p=.02). CONCLUSIONS In patients with postoperative CT imaging (43%), the freehand technique was found to be more accurate than CT-based navigation for C2 pedicle or pars screw placement. Complication rates did not differ between the two techniques in this study.

Halo Vest Immobilization

The halo vest is the most effective brace for restricting motion in the upper cervical spine. Although the indications for nonsurgical management with the halo vest are a topic of debate, the halo vest is frequently used to treat fractures such as Jefferson fractures, odontoid fractures, and hangman’s fractures. Conservative management with the halo vest may avoid the risk of surgery; however, it is not a completely benign intervention. The weight and constriction of the vest impair swallowing, pulmonary function, and mobility. The ability of the patient to tolerate immobilization with the halo vest is an important consideration before its application. One key to avoiding complications with the halo vest is to select an appropriate location for the halo pins. Structures that must be avoided include the frontal sinus, supraorbital nerve, and temporalis muscle. After application of the halo vest, careful clinical and radiographic follow-up should be conducted in all cases to ensure that the patient is tolerating the vest and that it is effective in restricting cervical motion.

A novel duraplasty technique following fenestration of a massive lumbar arachnoid cyst in a patient with scoliosis: technical case report

When a dural defect is encountered during spine surgery, the dura mater must be reconstituted to minimize the occurrence of minor or major life-threatening sequelae. The neurosurgical literature lacks strategies for managing large dural defects encountered during surgery. The authors describe a 24-year-old man who developed cauda equina syndrome secondary to altered CSF flow in a large thoracolumbar arachnoid cyst. Surgical decompression and fenestration of the arachnoid cyst were performed, and the large dural defect was treated using a multilayer closure with collagen matrix, titanium mesh, and methylmethacrylate. At his 24-month postoperative follow-up, the patient had recovered full strength in his legs, and his sensory deficits and sexual dysfunction had resolved. His incision had healed well, and there were no signs of pseudomeningocele. He had no additional positional headaches. The defect was managed effectively with this technique. Although this technique is not a first-line strategy for dural closure in the spine, it can be considered in challenging cases when large dural defects are not amenable to traditional closure techniques.