Impact of surgical risk factors for non-union on lumbar spinal fusion outcomes using cellular bone allograft at 24-months follow-up.

BACKGROUND: The current report investigates fusion rates and patient-reported outcomes following lumbar spinal surgery using cellular bone allograft (CBA) in patients with risk factors for non-union. METHODS: A prospective, open label study was conducted in subjects undergoing lumbar spinal fusion with CBA (NCT02969616) to assess fusion success rates and patient-reported outcomes in subjects with risk factors for non-union. Subjects were categorized into low-risk (≤ 1 risk factors) and high-risk (> 1 risk factors) groups. Radiographic fusion status was evaluated by an independent review of dynamic radiographs and CT scans. Patient-reported outcome measures included quality of life (EQ-5D), Oswestry Disability Index (ODI) and Visual Analog Scales (VAS) for back and leg pain. Adverse event reporting was conducted throughout 24-months of follow-up. RESULTS: A total of 274 subjects were enrolled: 140 subjects (51.1%) were categorized into the high-risk group (> 1 risk factor) and 134 subjects (48.9%) into the low-risk group (≤ 1 risk factors). The overall mean age at screening was 58.8 years (SD 12.5) with a higher distribution of females (63.1%) than males (36.9%). No statistical difference in fusion rates were observed between the low-risk (90.0%) and high-risk (93.9%) groups (p > 0.05). A statistically significant improvement in patient-reported outcomes (EQ-5D, ODI and VAS) was observed at all time points (p < 0.05) in both low and high-risk groups. The low-risk group showed enhanced improvement at multiple timepoints in EQ-5D, ODI, VAS-Back pain and VAS-Leg pain scores compared to the high-risk group (p < 0.05). The number of AEs were similar among risk groups. CONCLUSIONS: This study demonstrates high fusion rates following lumbar spinal surgery using CBA, regardless of associated risk factors. Patient reported outcomes and fusion rates were not adversely affected by risk factor profiles. TRIAL REGISTRATION: NCT02969616 (21/11/2016).

Adjunctive Use of Bone Growth Stimulation Increases Cervical Spine Fusion Rates in Patients at Risk for Pseudarthrosis.

STUDY DESIGN: A prospective multicenter clinical trial (NCT03177473) was conducted with a retrospective cohort used as a control arm. OBJECTIVE: The purpose of this study was to evaluate cervical spine fusion rates in subjects with risk factors for pseudarthrosis who received pulsed electromagnetic field (PEMF) treatment. SUMMARY OF BACKGROUND DATA: Certain risk factors predispose patients to pseudarthrosis, which is associated with prolonged pain, reduced function, and decreased quality of life. METHODS: Subjects in the PEMF group were treated with PEMF for 6 months postoperatively. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast). RESULTS: A total of 213 patients were evaluated (PEMF, n=160; Control, n=53). At baseline, the PEMF group had a higher percentage of subjects who used nicotine ( P =0.01), had osteoporosis ( P <0.05), multi-level disease ( P <0.0001), and were >65 years of age ( P =0.01). The PEMF group showed over two-fold higher percentage of subjects that had ≥3 risk factors (n=92/160, 57.5%) compared with the control group (n=14/53, 26.4%). At the 12-month follow-up, the PEMF group demonstrated significantly higher fusion rates compared with the control (90.0% vs. 60.4%, P <0.05). A statistically significant improvement in fusion rate was observed in PEMF subjects with multi-level surgery ( P <0.0001) and high BMI (>30 kg/m 2 ; P =0.0021) when compared with the control group. No significant safety concerns were observed. CONCLUSIONS: Adjunctive use of PEMF stimulation provides significant improvements in cervical spine fusion rates in subjects having risk factors for pseudarthrosis. When compared with control subjects that did not use PEMF stimulation, treated subjects showed improved fusion outcomes despite being older, having more risk factors for pseudarthrosis, and undergoing more complex surgeries.

Twenty-four-month interim results from a prospective, single-arm clinical trial evaluating the performance and safety of cellular bone allograft in patients undergoing lumbar spinal fusion.

BACKGROUND: Autologous bone grafts are the gold standard for spinal fusion; however, harvesting autologous bone can result in donor site infection, hematomas, increased operative time, and prolonged pain. Cellular bone allografts (CBAs) are a viable alternative that avoids the need for bone harvesting and may increase fusion success alone or when used as an adjunct material. The present study examined the efficacy and safety of CBA when used as an adjunct graft material to lumbar arthrodesis. METHODS: A prospective, single-arm, multicenter clinical trial (NCT02969616) was conducted in adult subjects (> 18 years of age) undergoing lumbar spinal fusion with CBA graft (CBA used as primary (≥ 50% by volume), with augmentation up to 50%). Radiographic fusion status was assessed by an independent review of dynamic radiographs and CT scans. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), and Visual Analog Scales (VAS) score for back and leg pain. Adverse events were assessed through the 24-month follow-up period. The presented data represents an analysis of available subjects (n = 86) who completed 24 months of postoperative follow-up at the time the data was locked for analysis. RESULTS: Postoperative 24-month fusion success was achieved in 95.3% of subjects (n = 82/86) undergoing lumbar spinal surgery. Clinical outcomes showed statistically significant improvements in ODI (46.3% improvement), VAS-Back pain (75.5% improvement), and VAS-Leg pain (85.5% improvement) (p < 0.01) scores at Month 24. No subject characteristics or surgical factors were associated with pseudoarthrosis. A favorable safety profile with a limited number of adverse events was observed. CONCLUSIONS: The use of CBA as an adjunct graft material showed high rates of successful lumbar arthrodesis and significant improvements in pain and disability scores. CBA provides an alternative to autograft with comparable fusion success rates and clinical benefits. TRIAL REGISTRATION: NCT02969616.

The translabyrinthine approach in residency training. "Step by step" surgical anatomy from the dissection laboratory to the operative room.

Surgical anatomy training in a dedicated research laboratory and attendance to focused "hands-on" dissection courses are of high educational importance in order to acquire and maintain surgical expertise in skull base surgery, both for young and more experienced surgeons. Nevertheless, transitioning surgical skills and anatomic knowledge from the laboratory to the operative room it is not free of challenges, especially during skull base approaches where the three-dimensional surgical orientation can be quite complex. We present a "step-by-step" and "side-by-side" surgical anatomy report on a translabyrinthine approach that was practiced in the laboratory then performed in the operative room by the surgical team, and we compare surgical anatomy exposures while discussing intraoperative techniques, nuances and challenges, both in the laboratory and the operative room.

Lumbar Discectomy and Reoperation Among Workers' Compensation Cases in Florida and New York: Are Treatment Trends Similar to Other Payer Types?

OBJECTIVE: The aim of this study was to better understand current treatment trends and revision rates for lumbar disc herniation (LDH) in the workers' compensation (WC) population compared with other payer types. METHODS: This was a retrospective analysis of outpatient claims data from Florida and New York during 2014 to 2016. RESULTS: WC patients were less likely to undergo discectomy in Florida (15% vs 19%; P < 0.001) and New York (10% vs 15%; P < 0.001). The odds of WC patients undergoing revision discectomy were 1.5 times greater than patients covered by private payers or all other non-WC payers (P = 0.002). CONCLUSIONS: WC patients undergo discectomy significantly less often than non-WC counterparts, which may be related to a higher risk of reoperation. New evidence-based treatments, such as annular repair, may be critical to advancing care in this unique population.

Novel technique for preoperative pedicle localization in spinal surgery with challenging anatomy.

Accurately localizing a spine level in the thoracic spine is often not easily achieved with the existing imaging modalities available in the operating room. The coordination of the preoperative imaging pathology with intraoperative imaging is even more difficult in patients with challenging anatomy. Using standard percutaneous techniques, the authors placed a radiopaque embolization coil into the pedicle of interest under biplanar fluoroscopy in 1 patient. Thoracic spine MRI along with scout MRI was then performed to confirm coil marker placement in relation to the actual spine pathology prior to surgical intervention. No complications were observed during placement of the radiopaque marker. Intraoperatively, the marker was immediately and easily visualized, leading to a confident identification of the correct thoracic spinal level. The preoperative placement of a radiopaque marker into the vertebral pedicle of the identified pathological level combined with postplacement MRI verification provides an advantage over previously proposed techniques in the literature.

The lateralization accuracy of inferior petrosal sinus sampling in 501 patients with Cushing's disease.

CONTEXT: It is often difficult to find an adenoma in patients with Cushing's disease (CD) whose preoperative magnetic resonance imaging (MRI) is normal. Better localizing modalities are needed. OBJECTIVE: The aim of this study was to determine the accuracy of inferior petrosal sinus sampling (IPSS) in predicting adenoma lateralization. DESIGN AND SETTING: We conducted a prospective observational study at a tertiary care clinical research center. PATIENTS: A total of 501 consecutive patients (363 female) with confirmed ACTH adenomas and IPSS were included. MAIN OUTCOME MEASURE: We measured the accuracy of IPSS to predict the intrasellar location of an adenoma. RESULTS: IPSS confirmed a pituitary source of ACTH secretion in 491 patients (98%). All 10 patients with false-negative results had peak IPSS ACTH concentrations (before or after CRH) of < 400 pg/ml. Interpetrosal (side-to-side) ratios were ≥ 1.4 in 491 patients (98%). This ratio correctly predicted lateralization in 273 of 396 patients (positive predictive value = 69%) with a lateral adenoma. Left-sided IPSS lateralization (P = .008) and consistent lateralization before and after CRH administration (P = .02) were associated with enhanced accuracy. When positive, preoperative MRI correlated with adenoma location in 171 of 201 patients (positive predictive value = 86%). CONCLUSIONS: Potential false-negative results, the most common type of diagnostic error with IPSS for the differential diagnosis of CS, can be identified by peak IPSS ACTH values < 400 pg/ml. When MRI is normal, IPSS can be used to guide surgical exploration in patients with negative preoperative imaging. However, because of the limited accuracy of lateralization, thorough exploration of the pituitary gland is required when an adenoma is not readily discovered based on predicted location.

Outcome of surgical treatment of 200 children with Cushing's disease.

CONTEXT: Factors influencing the outcome of surgical treatment of pediatric Cushing's disease (CD) have not been fully established. OBJECTIVE: The aim of this study was to examine features influencing the outcome of surgery for pediatric CD. DESIGN: In this prospective observational study, the clinical, imaging, endocrinological, and operative outcomes were analyzed in consecutive patients treated at the National Institutes of Health (NIH) from 1982 through 2010. SETTING: The study was conducted in a tertiary referral center. RESULTS: Two hundred CD patients (106 females, 94 males) were included. Mean age at symptom development was 10.6 ± 3.6 years (range, 4.0 to 19.0 y). Mean age at NIH operation was 13.7 ± 3.7 years. Twenty-seven patients (13%) had prior surgery at another institution. Magnetic resonance imaging identified adenomas in 97 patients (50%). When positive, magnetic resonance imaging accurately defined a discrete adenoma in 96 of the 97 patients (99%), which was more accurate than the use of ACTH ratios during inferior petrosal sinus sampling to determine adenoma lateralization (accurate in 72% of patients without prior surgery). A total of 195 of the 200 patients (98%) achieved remission after surgery (189 [97%] were hypocortisolemic; 6 [3%] were eucortisolemic postoperatively). Factors associated with initial remission (P < .05) included identification of an adenoma at surgery, immunohistochemical ACTH-producing adenoma, and noninvasive ACTH adenoma. Younger age, smaller adenoma, and absence of cavernous sinus wall or other dural invasion were associated with long-term remission (P < .05). A minimum morning serum cortisol of less than 1 µg/dl after surgery had a positive predictive value for lasting remission of 96%. CONCLUSIONS: With rare disorders, such as pediatric CD, enhanced outcomes are obtained by evaluation and treatment at centers with substantial experience. Resection of pituitary adenomas in pediatric CD in that setting can be safe, effective, and durable. Early postoperative endocrine testing predicts lasting remission. Because lasting remission is associated with younger age at surgery, smaller adenomas, and lack of dural invasion, early diagnosis should improve surgical outcome.

Immediate titanium mesh cranioplasty for treatment of postcraniotomy infections.

OBJECTIVE: Postcraniotomy infections have generally been treated by debridement of infected tissues, disposal of the bone flap, and delayed cranioplasty several months later to repair the resulting skull defect. Debridement followed by retention of the bone flap has also been advocated. Here we propose an alternative operative strategy for the treatment of postcraniotomy infections. METHODS: Two patients presenting with clinical and radiographic signs and symptoms of postcraniotomy infections were treated by debridement, bone flap disposal, and immediate titanium mesh cranioplasty. The patients were subsequently administered antibiotics, and their clinical courses were followed. RESULTS: The patients treated in this fashion did not have recurrence of their infections during 3-year follow-up periods. CONCLUSIONS: Surgical debridement, bone flap disposal, and immediate titanium mesh cranioplasty may be a suitable option for the treatment of postcraniotomy infections. This treatment strategy facilitates the eradication of infectious sources and obviates the risks and costs associated with a second surgical procedure.

The role of adjuvant radiation therapy in the management of high-grade gliomas.

The purpose of this article is to update the neurosurgical community on the role of adjuvant radiation therapy in the management of patients with high-grade glioma. This information guides clinicians in the multidisciplinary management of these patients via a review of the literature describing current treatment paradigms as well as new avenues of investigation.

Radiation necrosis following treatment of high grade glioma--a review of the literature and current understanding.

Radiation therapy is an integral part of the standard treatment paradigm for malignant gliomas, with proven efficacy in randomized control trials. Radiation treatment is not without risk however, and radiation injury occurs in a certain proportion of patients. Difficulties in differentiating recurrence from radiation injury complicate the treatment course and can compromise care. These complexities are compounded by the recent distinction of two types of radiation injury: pseudoprogression and radiation necrosis, which are likely the result of radiation injury to the tumor and normal tissue, respectively. A thorough understanding of radiation-induced injury offers insights to guide further therapies. We detail the current knowledge of the mechanisms of radiation injury, along with potential targets for therapeutic intervention. Various diagnostic modalities are also described, in addition to the multiple options for treatment within the context of their pathophysiology and clinical efficacy. Radiation therapy is an integral part of the multidisciplinary management of gliomas, and the optimal diagnosis and management of radiation injury is paramount to improving patient outcomes.

Prospective evaluation of the characteristics and incidence of adenoma-associated dural invasion in Cushing disease.

OBJECT: Dural invasion by adrenocorticotropic hormone (ACTH)-secreting adenomas is a significant risk factor for incomplete resection and recurrence in Cushing disease (CD). Since ACTH-producing adenomas are often the smallest of the various types of pituitary tumors at the time of resection, examining their invasion provides the best opportunity to identify the precise sites of early dural invasion by pituitary adenomas. To characterize the incidence and anatomical distribution of dural invasion by ACTH-secreting adenomas, the authors prospectively and systematically analyzed features of dural invasion in patients with CD. METHODS: The authors prospectively studied consecutive patients with CD undergoing the systematic removal of ACTH-secreting adenoma and histological analysis of the anterior sella dura as well as other sites of dural invasion that were evident at surgery. Clinical, imaging, histological, and operative findings were analyzed. RESULTS: Eighty-seven patients with CD (58 females and 29 males) were included in the study. Overall, dural invasion by an ACTH-positive adenoma was histologically confirmed in 30 patients (34%). Eighteen patients (60% of dural invasion cases, 21% of all patients) had evidence of cavernous sinus wall invasion (4 of these patients also had other contiguous sites of invasion), and 12 patients (40% of dural invasion cases) had invasion of the sella dura excluding the cavernous sinus wall. Eleven patients (13% all patients) had invasion of the routinely procured anterior sella dura specimen. Preoperative MR imaging revealed an adenoma in 64 patients (74%) but accurately predicted dural invasion in only 4 patients (22%) with cavernous sinus invasion and none of the patients with non-cavernous sinus invasion. Adenomas associated with dural invasion (mean ± SD, 10.9 ± 7.8 mm, range 2-37 mm) were significantly larger than those not associated with dural invasion (5.7 ± 2.1 mm, range 2.5-12 mm; p = 0.0006, Mann-Whitney test). CONCLUSIONS: Dural invasion by ACTH-producing adenomas preferentially occurs laterally into the wall of the cavernous sinus. Preoperative MR imaging infrequently detects dural invasion, including cavernous sinus invasion. Invasion is directly associated with tumor size. To provide a biochemical cure and avoid recurrence after resection, identification and removal of invaded sella dura, including the medial cavernous sinus wall, are necessary.

Management of von Hippel-Lindau disease-associated CNS lesions.

Patients with von Hippel-Lindau disease (VHL) often harbor significant disease burden within the CNS, specifically craniospinal-axis hemangioblastomas and endolymphatic sac tumors (ELSTs). The majority (60-80%) of patients with VHL harbor hemangioblastomas, and 10-15% will develop ELSTs. Advances in the understanding of the natural history and outcomes associated with the surgical management of VHL-associated tumors have led to improved management of patients with VHL. Optimizing indications for surgical intervention and refining of surgical techniques for these lesions can reduce patient morbidity associated with the management of this syndrome. In this article, we review the various aspects of perioperative management of patients with VHL, surgical indications and general operative principles for the management of hemangioblastomas and ELSTs, and outcomes associated with the surgical treatment of these tumors.

Hearing preservation in the resection of vestibular schwannomas: patterns of hearing preservation and patient-assessed hearing function.

OBJECT: No extant literature documents the analysis of patient perceptions of hearing as a corollary to objective audiometric measures in patients with vestibular schwannoma (VS), or acoustic neuroma. Therefore, using objective audiometric data and patient perceptions of hearing function as outlined on a questionnaire, the authors evaluated the hearing of patients who underwent VS resection. METHODS: This investigation involved a retrospective review of 176 patients who had undergone VS resections in which hearing preservation was a goal. Both pre- and postoperative audiometry, expressed as a speech discrimination score (SDS) and pure tone threshold average (PTA), were performed, and the results were analyzed. Intraoperative auditory brainstem responses were also recorded. Eighty-seven of the patients (49.4%) completed a postoperative questionnaire designed to assess hearing function in a variety of social and auditory situations. Multiple linear regression analyses were completed to compare available audiometric results with questionnaire responses for each patient. RESULTS: One hundred forty-two patients (80.7%) had PTA and SDS audiometric data pertaining to the surgically treated ear; 94 of these patients (66.2%) had measurable postoperative hearing, as defined by a PTA < 120 dB or SD > 0%. Eighty-seven patients (49.4%) completed the retrospective questionnaire, and 74 of them had complete audiometric data and thus were included in a comparative analysis. Questionnaire data showed major postoperative subjective hearing decrements, even among patients with the same pre- and postoperative objective audiometric hearing status. Moreover, the subscore reflecting hearing while exposed to background noise, or the "cocktail party effect," characterized the most significant patient-perceived hearing deficit following VS resection. CONCLUSIONS: The authors' analysis of a patient-perceived hearing questionnaire showed that hearing during exposure to background noise, or the cocktail party effect, represents a significant postoperative hearing deficit and that patient perception of this deficit has a strong relation with audiometric data. Furthermore, questionnaire responses revealed a significant disparity between subjective hearing function and standard audiometrics such that even with similar levels of audiometric data, subjective measures of hearing, especially the cocktail party effect, decreased postoperatively. The authors posit that the incorporation of patient-perceived hearing function evaluation along with standard audiometry is an illustrative means of identifying subjective hearing deficits after VS resection and may ultimately aid in specific and subsequent treatment for these patients.

Long-term outcome after resection of brainstem hemangioblastomas in von Hippel-Lindau disease.

OBJECT: Brainstem hemangioblastomas are frequently encountered in patients with von Hippel-Lindau (VHL) disease. These tumors can cause significant morbidity, and their optimal management has not been defined. To better define the outcome and management of these tumors, the authors analyzed the long-term results in patients who underwent resection of brainstem hemangioblastomas. METHODS: Consecutive patients with VHL disease who underwent resection of brainstem hemangioblastomas with a follow-up of 12 months or more were included in this study. Serial functional assessments, radiographic examinations, and operative records were analyzed. RESULTS: Forty-four patients (17 male and 27 female) underwent 51 operations for resection of 71 brainstem hemangioblastomas. The most common presenting symptoms were headache, swallowing difficulties, singultus, gait difficulties, and sensory abnormalities. The mean follow-up was 5.9 ± 5.0 years (range 1.0-20.8 years). Immediately after 34 operations (66.7%), the patients remained at their preoperative functional status; they improved after 8 operations (15.7%) and worsened after 9 operations (17.6%) as measured by the McCormick scale. Eight (88.9%) of the 9 patients who were worse immediately after resection returned to their preoperative status within 6 months. Two patients experienced functional decline during long-term follow-up (beginning at 2.5 and 5 years postoperatively) caused by extensive VHL disease-associated CNS disease. CONCLUSIONS: Generally, resection of symptomatic brainstem hemangioblastomas is a safe and effective management strategy in patients with VHL disease. Most patients maintain their preoperative functional status, although long-term decline in functional status may occur due to VHL disease-associated progression.

Treatment of third ventricular choroid plexus papilloma in an infant with embolization alone.

The authors present the case of a 3-month-old boy with a third ventricular tumor consistent with a choroid plexus papilloma. This child presented with macrocephaly, irritability, inability to roll over, and vomiting. He was found to have an enlarged head circumference, a full and tense fontanel, splayed sutures, and forced downward gaze. Imaging revealed severe ventriculomegaly and a brightly enhancing third ventricular lesion consistent with papilloma. Treatment planning included placement of a ventriculoperitoneal shunt to treat hydrocephalus and to allow the child to grow prior to resection. Due to the vascular nature of these tumors and the age of this child, the tumor was embolized with a plan for eventual resection; however, embolization resulted in involution and total regression of the tumor. There is no residual disease at last follow-up of 16 months. In this specific scenario of a choroid plexus papilloma in an infant, when operative intervention may be technically difficult and associated with significant morbidity, embolization with close observation may be a valid treatment option. If used, the patient would need to be closely followed for evidence of residual or recurrent disease, which would require operative intervention.

Pathologic cervical burst fracture presenting with airway compromise.

Mechanical airway compromise following cervical spine injury or fracture is a rare but known entity. It most commonly is the result of the development of a retropharyngeal hematoma or prevertebral soft tissue edema that obstructs the airway, leading to respiratory distress and emergent need for airway management and possible surgical intervention. We present a novel case of airway compromise following a C3 burst fracture without associated retropharyngeal hematoma or prevertebral soft tissue edema. Surgical management is discussed, and a review of relevant literature is provided. Pathological cervical spine fracture must be included in the differential diagnosis of a patient presenting with acute airway obstruction of unknown etiology.

Fourth ventricular chordoid meningioma.

The chordoid variant of meningioma is a histological subtype which carries with it a more aggressive clinical course and a propensity for recurrence. Similar to other meningioma subtypes, this lesion is encountered typically in the supratentorial compartment, often along the cerebral convexities. The chordoid meningioma subtype is found primarily in the adult population, and may occasionally be associated with the systemic manifestations of Castleman's disease. We present an adult patient with a rare chordoid meningioma located within the fourth ventricle. This lesion was treated with gross total resection. Chordoid meningioma must be considered within the differential diagnosis of intraventricular tumors. This histological subtype of meningioma warrants close follow-up. The patient must also be evaluated for systemic manifestations of Castleman's disease.

Pleomorphic xanthoastrocytoma presenting with life-threatening hemorrhage in a child.

Pleomorphic xanthoastrocytomas are glial-based tumors that arise most frequently in young patients and usually follow a more benign and indolent clinical course than their other glial-based tumor counterparts. These tumors most frequently present with seizures, and only 3 previous case reports exist of hemorrhagic tumor as the clinical presentation. The authors present the first case of life-threatening intracerebral hemorrhage from pleomorphic xanthoastrocytoma in a child.