Single-center outcomes for percutaneous pedicle screw fixation in metastatic spinal lesions: can spontaneous facet fusion occur?

OBJECTIVE: Survival of cancer patients continues to improve with systemic treatment advancements, leading to an increase in cancer-related complications such as pathological spinal fractures. In this study, the authors aimed to evaluate the outcome of percutaneous stabilization with cement augmentation of the pedicle screws in the management of patients with metastatic cancer to the spine. METHODS: The authors reviewed a retrospective case series of 74 patients with symptomatic pathological spine fractures treated with cement-augmented pedicle screws implanted with a percutaneous technique. The mean imaging follow-up was 11.3 months. Data on demographics, clinical outcomes, and complications were collected. Cement extravasation, spinal hardware integrity, and fusion rates were assessed on CT scans. RESULTS: Among 50 patients with follow-up imaging, 23 patients (46%) showed facet joint fusion. The length of segmental stabilization was not a significant predictor of the occurrence of fusion. Pre- or postoperative radiation therapy, postoperative chemotherapy, and the location of spinal lesions did not have a statistically significant effect on the occurrence of fusion. Patients older than 60 years of age were more likely to have fusion across facet joints compared with younger patients. There was a significant difference in the mean visual analog scale pain score, with 6.28 preoperatively and 3.41 postoperatively, regardless of fusion status (p < 0.001). Cement extravasation was seen in 51% of the cohort, but in all instances, patients remained asymptomatic. Most importantly, the incidence of hardware failure was low (4%). CONCLUSIONS: Percutaneous fixation with cement-augmented pedicle screws in patients with pathological spine fractures provides an improvement in mechanical back pain, with a low incidence of failure, and in some patients, spontaneous facet fusion was observed. Further research is necessary with regard to both short-term benefits and long-term outcomes.

Stereotactic Body Radiation Therapy in Nonsurgical Patients with Metastatic Spinal Disease and Epidural Compression: A Retrospective Review.

BACKGROUND: In the setting of spinal metastases with epidural cord compression, radiosurgery is often only considered when there is sufficient separation between the epidural disease and the spinal cord. However, in patients who are nonsurgical candidates or those who prefer nonoperative management, there may be a benefit from stereotactic body radiation therapy, even when the epidural target is closer than the traditionally referenced 3 mm distance from the spinal cord. The purpose of this retrospective study is to evaluate our institution's experience in treating 20 such patients. METHODS: We reviewed records of all patients treated with stereotactic body radiation therapy for spinal metastases at our institution from January 2010 to January 2016, with follow-up through December 2016. The primary end point was local progression of disease. Local progression was defined as clear radiographic disease growth on follow-up imaging or worsening clinical symptoms in the absence of evidence for radiation myelopathy. RESULTS: Local control was obtained in 55% of patients meeting these criteria without a single case of radiation myelitis. Most patients with disease progression were able to undergo additional local treatment. CONCLUSIONS: Although local control was less than expected when compared with spine radiosurgery with adequate separation between the target and spinal cord, this treatment appears to be a viable option in the nonsurgical candidate.

Dexamethasone-Mediated Upregulation of Calreticulin Inhibits Primary Human Glioblastoma Dispersal Ex Vivo.

Dispersal of Glioblastoma (GBM) renders localized therapy ineffective and is a major cause of recurrence. Previous studies have demonstrated that Dexamethasone (Dex), a drug currently used to treat brain tumor-related edema, can also significantly reduce dispersal of human primary GBM cells from neurospheres. It does so by triggering α5 integrin activity, leading to restoration of fibronectin matrix assembly (FNMA), increased neurosphere cohesion, and reduction of neurosphere dispersal velocity (DV). How Dex specifically activates α5 integrin in these GBM lines is unknown. Several chaperone proteins are known to activate integrins, including calreticulin (CALR). We explore the role of CALR as a potential mediator of Dex-dependent induction of α5 integrin activity in primary human GBM cells. We use CALR knock-down and knock-in strategies to explore the effects on FNMA, aggregate compaction, and dispersal velocity in vitro, as well as dispersal ex vivo on extirpated mouse retina and brain slices. We show that Dex increases CALR expression and that siRNA knockdown suppresses Dex-mediated FNMA. Overexpression of CALR in GBM cells activates FNMA, increases compaction, and decreases DV in vitro and on explants of mouse retina and brain slices. Our results define a novel interaction between Dex, CALR, and FNMA as inhibitors of GBM dispersal.

Dexamethasone-mediated inhibition of Glioblastoma neurosphere dispersal in an ex vivo organotypic neural assay.

Glioblastoma is highly aggressive. Early dispersal of the primary tumor renders localized therapy ineffective. Recurrence always occurs and leads to patient death. Prior studies have shown that dispersal of Glioblastoma can be significantly reduced by Dexamethasone (Dex), a drug currently used to control brain tumor related edema. However, due to high doses and significant side effects, treatment is tapered and discontinued as soon as edema has resolved. Prior analyses of the dispersal inhibitory effects of Dex were performed on tissue culture plastic, or polystyrene filters seeded with normal human astrocytes, conditions which inherently differ from the parenchymal architecture of neuronal tissue. The aim of this study was to utilize an ex-vivo model to examine Dex-mediated inhibition of tumor cell migration from low-passage, human Glioblastoma neurospheres on multiple substrates including mouse retina, and slices of mouse, pig, and human brain. We also determined the lowest possible Dex dose that can inhibit dispersal. Analysis by Two-Factor ANOVA shows that for GBM-2 and GBM-3, Dex treatment significantly reduces dispersal on all tissue types. However, the magnitude of the effect appears to be tissue-type specific. Moreover, there does not appear to be a difference in Dex-mediated inhibition of dispersal between mouse retina, mouse brain and human brain. To estimate the lowest possible dose at which Dex can inhibit dispersal, LogEC50 values were compared by Extra Sum-of-Squares F-test. We show that it is possible to achieve 50% reduction in dispersal with Dex doses ranging from 3.8 x10-8M to 8.0x10-9M for GBM-2, and 4.3x10-8M to 1.8x10-9M for GBM-3, on mouse retina and brain slices, respectively. These doses are 3-30-fold lower than those used to control edema. This study extends our previous in vitro data and identifies the mouse retina as a potential substrate for in vivo studies of GBM dispersal.

Delayed Occipital Artery Pseudoaneurysm Following Blunt Force Trauma.

BACKGROUND: Occipital artery pseudoaneurysms are extremely rare pathologies that manifest after traumatic injury; only 11 cases have been reported in the literature. Because of their low incidence and vague symptoms, the initial diagnosis can be difficult. However, for correctly diagnosed occipital artery pseudoaneurysms, many successful treatment modalities exist. METHODS: We review the pathology of occipital pseudoaneurysms, elucidate the reasons for their rarity, discuss effective diagnostic measures, and discuss the currently available treatment options. We also present a case of a 16-year-old boy who sustained blunt force trauma in May 2014 and presented 6 months later with a painful, pulsatile mass in the occipital region. RESULTS: The patient underwent surgical resection to alleviate the pain and the potential risk of hemorrhage. He experienced complete resolution of pain and associated symptoms. CONCLUSIONS: Our case highlights the fact that occipital swelling, a significant initial sign of pseudoaneurysm development, can be delayed. Therefore, occipital artery pseudoaneurysms cannot be ruled out of the differential diagnosis based on time course alone. Surgical resection is a quick and effective method for relief of severe pain resulting from occipital artery pseudoaneurysms. Although they are rare entities, occipital artery pseudoaneurysms must be considered in the differential diagnosis of cases of pulsatile mass lesions in the posterior scalp.

Eliminating unnecessary routine head CT scanning in neurologically intact mild traumatic brain injury patients: implementation and evaluation of a new protocol.

OBJECTIVE The utility of routine repeat head CT (HCT) scans in the management of minimal head injury (MHI) patients with an intracranial hemorrhage (ICH) has been questioned in multiple studies. All these studies analyzed this by obtaining a repeat HCT study, and none examined the effects of eliminating these routine HCT studies in neurologically intact patients. The authors' institution implemented a new "Neurologic Observation without Repeat HCT" (NORH) protocol with no repeat HCT scanning for patients admitted for MHI and ICH whose neurological status was maintained or improved to a Glasgow Coma Scale score of 15 at 24 hours after admission. This purpose of this study was to assess the outcomes and safety of this novel protocol. METHODS Records of patients who sustained blunt trauma MHI and an ICH and/or skull fracture on initial HCT between January 1, 2009, and December 31, 2012, were retrieved from the trauma registry of a Level I trauma center. The authors analyzed 95 patients in whom the NORH protocol was followed. Outcome measures included death, emergency department readmission, neurosurgical intervention, delayed repeat HCT, and length of stay. RESULTS The NORH protocol was followed for 95 patients; 83% of the patients were male, the average age was 38 ± 16.0 years old, and the most common cause of trauma was assault (35%). Of the 95 patients in whom the NORH protocol was followed, 8 (8%) had a delayed repeat HCT study (> 24 hours) after admission, but none resulted in neurosurgical intervention because of progression of ICH. The average length of stay was 4 ± 7.2 days. None of the patients were readmitted to the hospital. CONCLUSIONS Implementation of the NORH protocol (eliminating routine follow-up HCT) resulted in very low rates of delayed neurological deterioration, no late neurosurgical interventions resulting from ICH progression, very few emergency department revisits, and no readmissions. For a select group of MHI patients with ICH, the NORH protocol is safe and effective, and can reduce radiation exposure and costs.

Endovascular Management of Spinal Dural Arteriovenous Fistulas.

Spinal vascular malformations, although rare, cause devastating disease. These malformations are commonly categorized as follows: spinal arteriovenous malformations (AVMs), dural arteriovenous fistulas (DAVFs), spinal hemangiomas, cavernous angiomas, and aneurysms. Spinal DAVFs (SDAVFs), or type 1 spinal AVMs, occur most frequently, representing ∼ 60 to 80% of vascular malformations of the spinal cord. While previously microsurgical treatment was considered the gold standard in the treatment of SDAVFs, recent advancements in technology-advancements of magnetic resonance imaging as a screening examination, contrast-enhanced magnetic resonance angiography, multidetector computed tomography as preangiographic evaluations, digital subtraction angiography, diagnostic catheters, and embolization materials-have made endovascular treatment a possible option. We review the treatment of SDAVFs, primarily discussing the endovascular management of these lesions.

Titanium mesh-assisted dural tenting for an expansile suboccipital cranioplasty in the treatment of Chiari 1 malformation.

Cerebellar ptosis and dural prolapse are known complications after posterior craniocervical decompression of Chiari 1 malformation (CM1), and are associated with larger craniectomies, epidural scarring and intradural adhesions. Although management of these complications has been well documented, little has been reported in regards to their prevention. We describe our variation of the posterior fossa decompression technique for CM1 using a titanium mesh-assisted dural tenting expansile cranioplasty to prevent both cerebellar ptosis and dural prolapse. A watertight dural augmentation patch is performed after posterior craniocervical decompression. A titanium mesh cranioplasty is performed to cover the superior aspect of the craniectomy. The duraplasty is then tented to the titanium mesh plate with several interrupted sutures. The titanium mesh plate was intended to prevent postoperative cerebellar ptosis or sag, while the dural tenting was performed to prevent delayed collapse and restenosis of the cistern magna. Four patients with CM1 underwent this technique without complication. Postoperative MRI did not demonstrate cerebellar ptosis, restenosis or collapse of the cisterna magna. The expansile suboccipital cranioplasty with titanium mesh-assisted dural tenting technique is a simple and efficient strategy that may be useful to prevent cerebellar ptosis and dural prolapse and maintain the patency of the surgically created neo-cisterna magna.