Alexis retractor efficacy in transthoracic thoracoscopically assisted discectomy for thoracic disc herniations.

PURPOSE: A transthoracic anterior or lateral approach for giant thoracic disc herniations is a complex operation which requires optimal exposure and maximal visualisation. Traditional metal rigid retractors may inflict significant skin trauma especially with prolonged operative use and limit the working angles of endoscopic instrumentation at depth. We pioneer the use of the Alexis retractor in transthoracic thoracoscopically assisted discectomy for the first time. METHODS: The authors describe and demonstrate the technical use of the Alexis retractor during operative cases. Patient positioning, clinical rationale and operative nuances are elucidated for readers to gain an appreciation of the transthoracic approach to thoracic disc herniations. RESULTS: The advantages of the Alexis retractor include minimally invasive circumferential flexible retraction, facilitation of bimanual instrument use, diminished risk of surgical site infections and reduced rib retraction leading to less postoperative pain. CONCLUSION: Use of the flexible and intuitive Alexis retractor maximises operative exposure and is an effective adjunct when performing complex transthoracic approaches for thoracic disc herniations.

Survival outcomes of intracranial extraventricular neurocytomas: a systematic review and individual patient data meta-analysis.

OBJECTIVE: The rarity of intracranial extraventricular neurocytomas (EVNs) has precluded accurate definition of its surgical characteristics to date. The authors present the first survival analysis of this unique entity that aims to clarify tumor characteristics, surgical outcomes, and efficacy of postoperative adjuvant therapy. METHODS: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Searches of the MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Database of Systematic Reviews databases were performed from inception to date. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Prognostic variables were age, sex, tumor consistency, extent of resection, and receipt of postoperative adjuvant therapy. Survival data were analyzed using Kaplan-Meier survival curves and the log-rank test to compare dichotomized cohorts. Multivariate Cox regression models were constructed, interrogated with Schoenfeld residuals, and subsequently utilized to identify independent prognostic factors. Risk of bias was assessed with the Mayo Clinic instrument. RESULTS: Five hundred fourteen articles were initially retrieved, which was distilled to 10 included articles consisting of 101 cases of intracranial EVNs. The 5-year OS rate was 90.4% (95% CI 81.8%-99.8%) and the PFS rate was 48.6% (95% CI 34.46%-68.8%). The median PFS was 60 months. Patients younger than 50 years of age experienced superior OS (p = 0.03) and PFS (p < 0.01). Gross-total resection (GTR) was superior to subtotal resection (STR) in reducing mortality (p < 0.01). Adjuvant therapy following either STR or GTR did not significantly improve survival. CONCLUSIONS: Intracranial EVNs are rare tumors that portend a poorer prognosis than central neurocytomas, despite both being WHO grade 2 tumors. Complete surgical extirpation is the cornerstone of management. There is no clearly established role for adjuvant postoperative therapy, but each case should be managed on an individual basis.

Saccular posterior cerebral artery aneurysm encased within a lipoma.

We present a case of a man in his 80s with an incidental posterior cerebral artery aneurysm encased within a lipoma. The literature surrounding the incidence and intricate relationship of lipomas to cerebral aneurysms is reviewed. Lipomas are proposed to be derived from maldifferentiated subarachnoid space. For this reason, lipomas are often associated with vascular malformations and may develop in conjunction with vascular malformations such as cerebral aneurysms. Hypothesised theories include the impediment of smooth muscle nutrient diffusion and the secretion of factors that weaken the arterial wall thereby predisposing to aneurysm formation. When lipomas neighbour cerebral vasculature, careful evaluation of the adjacent vessels should be conducted.

Risk Stratification of Elderly Patients Undergoing Spinal Surgery Using the Modified Frailty Index.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To validate the 11-item modified Frailty Index (mFI) as a perioperative risk stratification tool in elderly patients undergoing spine surgery. METHODS: All consecutive cases of spine surgery in patients aged 65 years or older between July 2016 and June 2018 at a state-wide trauma center were retrospectively reviewed. The primary outcome was post-operative major complication rate (Clavien-Dindo Classification ≥ III). Secondary outcome measures included the rate of all complications, 6-month mortality and surgical site infection. RESULTS: A total of 348 cases were identified. The major complication rate was significantly lower in patients with an mFI of 0 compared to ≥ 0.45 (18.3% versus 42.5%, P = .049). As the mFI increased from 0 to ≥ 0.45 there was a stepwise increase in risk of major complications (P < .001). Additionally, 6-month mortality rate was considerably lower when the mFI was 0 rather than ≥ 0.27 (4.2% versus 20.4%, P = .007). Multivariate analysis demonstrated an mFI ≥ 0.27 was significantly associated with an increased incidence of major complication (OR 2.80, 95% CI 1.46-5.35, P = .002), all complication (OR 2.93, 95% CI 1.70-15.11, P < .001), 6-month mortality (OR 7.39, 95% CI 2.55-21.43, P < .001) and surgical site infection (OR 4.43, 95% CI 1.71-11.51, P = .002). The American Society of Anesthesiologists' (ASA) index did not share a stepwise relationship with any outcome. CONCLUSION: The mFI is significantly associated in a gradated fashion with increased morbidity and mortality. Patients with an mFI ≥ 0.27 are at greater risk of major complications, all-complications, 6-monthy mortality, and surgical site infection.

Evolution of the AO Spine Sacral and Pelvic Classification System: a systematic review.

OBJECTIVE: The purpose of this study was to describe the genesis of the AO Spine Sacral and Pelvic Classification System in the context of historical sacral and pelvic grading systems. METHODS: A systematic search of MEDLINE, EMBASE, Google Scholar, and Cochrane databases was performed consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all existing sacral and pelvic fracture classification systems. RESULTS: A total of 49 articles were included in this review, comprising 23 pelvic classification systems and 17 sacral grading schemes. The AO Spine Sacral and Pelvic Classification System represents both the evolutionary product of these historical systems and a reinvention of classic concepts in 5 ways. First, the classification introduces fracture types in a graduated order of biomechanical stability while also taking into consideration the neurological status of patients. Second, the traditional belief that Denis central zone III fractures have the highest rate of neurological deficit is not supported because this subgroup often includes a broad spectrum of injuries ranging from a benign sagittally oriented undisplaced fracture to an unstable "U-type" fracture. Third, the 1990 Isler lumbosacral system is adopted in its original format to divide injuries based on their likelihood of affecting posterior pelvic or spinopelvic stability. Fourth, new discrete fracture subtypes are introduced and the importance of bilateral injuries is acknowledged. Last, this is the first integrated sacral and pelvic classification to date. CONCLUSIONS: The AO Spine Sacral and Pelvic Classification is a universally applicable system that redefines and reorders historical fracture morphologies into a rational hierarchy. This is the first classification to simultaneously address the biomechanical stability of the posterior pelvic complex and spinopelvic stability, while also taking into consideration neurological status. Further high-quality controlled trials are required prior to the inclusion of this novel classification within a validated scoring system to guide the management of sacral and pelvic injuries.

Variations in management of A3 and A4 cervical spine fractures as designated by the AO Spine Subaxial Injury Classification System.

OBJECTIVE: Optimal management of A3 and A4 cervical spine fractures, as defined by the AO Spine Subaxial Injury Classification System, remains controversial. The objectives of this study were to determine whether significant management variations exist with respect to 1) fracture location across the upper, middle, and lower subaxial cervical spine and 2) geographic region, experience, or specialty. METHODS: A survey was internationally distributed to 272 AO Spine members across six geographic regions (North America, South America, Europe, Africa, Asia, and the Middle East). Participants' management of A3 and A4 subaxial cervical fractures across cervical regions was assessed in four clinical scenarios. Key characteristics considered in the vignettes included degree of neurological deficit, pain severity, cervical spine stability, presence of comorbidities, and fitness for surgery. Respondents were also directly asked about their preferences for operative management and misalignment acceptance across the subaxial cervical spine. RESULTS: In total, 155 (57.0%) participants completed the survey. Pooled analysis demonstrated that surgeons were more likely to offer operative intervention for both A3 (p < 0.001) and A4 (p < 0.001) fractures located at the cervicothoracic junction compared with fractures at the upper or middle subaxial cervical regions. There were no significant variations in management for junctional incomplete (p = 0.116) or complete (p = 0.342) burst fractures between geographic regions. Surgeons with more than 10 years of experience were more likely to operatively manage A3 (p < 0.001) and A4 (p < 0.001) fractures than their younger counterparts. Neurosurgeons were more likely to offer surgical stabilization of A3 (p < 0.001) and A4 (p < 0.001) fractures than their orthopedic colleagues. Clinicians from both specialties agreed regarding their preference for fixation of lower junctional A3 (p = 0.866) and A4 (p = 0.368) fractures. Overall, surgical fixation was recommended more often for A4 than A3 fractures in all four scenarios (p < 0.001). CONCLUSIONS: The subaxial cervical spine should not be considered a single unified entity. Both A3 and A4 fracture subtypes were more likely to be surgically managed at the cervicothoracic junction than the upper or middle subaxial cervical regions. The authors also determined that treatment strategies for A3 and A4 subaxial cervical spine fractures varied significantly, with the latter demonstrating a greater likelihood of operative management. These findings should be reflected in future subaxial cervical spine trauma algorithms.

Tumor characteristics and surgical outcomes of intracranial subependymomas: a systematic review and meta-analysis.

OBJECTIVE: The tumor characteristics and surgical outcomes of intracranial subependymomas are poorly defined. In this study the authors aimed to provide a comprehensive review of all clinical, pathological, radiological, and surgical aspects of this important neoplasm to inform future management strategies. METHODS: A systematic review and meta-analysis of MEDLINE, EMBASE, Cochrane, and Google Scholar databases adherent to PRISMA guidelines was conducted. RESULTS: Of the 1145 articles initially retrieved, 24 studies encompassing 890 cases were included. The authors identified 3 retrospective cohort studies and 21 case series, but no controlled trials. Mean age at presentation was 46.7 ± 18.1 years with a male predominance (70.2%). Common sites of tumor origin were the lateral ventricle (44.5%) and fourth ventricle (43.1%). Cumulative postoperative mortality and morbidity rates were 3.4% and 24.3% respectively. Meta-analysis revealed that male sex (HR 3.15, 95% CI 1.39-7.14, p = 0.006) was associated with poorer 5-year overall mortality rates. All-cause mortality rates were similar when performing subgroup meta-analyses for age (HR 0.50, 95% CI 0.03-7.36, p = 0.61), smaller subependymoma size (HR 1.51, 95% CI 0.78-2.92, p = 0.22), gross-total resection (HR 0.65, 95% CI 0.35-1.23, p = 0.18), and receipt of postoperative radiation therapy (HR 0.88, 95% CI 0.27-2.88, p = 0.84). Postoperative Karnofsky Performance Index scores improved by a mean difference of 1.62 ± 12.14 points (p = 0.42). The pooled overall 5-year survival rate was 89.2%, while the cumulative recurrence rate was 1.3% over a median follow-up ranging from 15.3 to 120.0 months. The pure subependymoma histopathological subtype was most prevalent (85.6%), followed by the mixed subependymoma-ependymoma tumor variant (13.7%). CONCLUSIONS: Surgical extirpation without postoperative radiotherapy results in excellent postoperative survival and functional outcomes in the treatment of intracranial subependymomas. Aggressive tumor behavior should prompt histological reevaluation for a mixed subependymoma-ependymoma subtype. Further high-quality controlled trials are still required to investigate this rare tumor.

Implant Removal Versus Implant Retention Following Posterior Surgical Stabilization of Thoracolumbar Burst Fractures: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: To compare biomechanical and functional outcomes between implant removal and implant retention following posterior surgical fixation of thoracolumbar burst fractures. METHODS: A search of the MEDLINE, EMBASE, Google Scholar and Cochrane Databases was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Of the 751 articles initially retrieved, 13 published articles pooling 673 patients were included. Meta-analysis revealed there was a statistically significant improvement in sagittal Cobb Angle by 16.48 degrees (9.13-23.83, p < 0.01) after surgical stabilization of thoracolumbar burst fractures. This correction decremented to 9.68 degrees (2.02-17.35, p < 0.01) but remained significant at the time of implant removal approximately 12 months later. At final follow-up, the implant removal group demonstrated a 10.13 degree loss (3.00-23.26, p = 0.13) of reduction, while the implant retention group experienced a 10.17 degree loss (1.79-22.12, p = 0.10). There was no statistically significant difference in correction loss between implant retention and removal cohorts (p = 0.97). Pooled VAS scores improved by a mean of 3.32 points (0.18 to 6.45, p = 0.04) in the combined removal group, but by only 2.50 points (-1.81 to 6.81, p = 0.26) in the retention group. Oswestry Disability Index scores also improved after implant removal by 7.80 points (2.95-12.64, p < 0.01) at 1 year and 11.10 points (5.24-16.96, p < 0.01) at final follow-up. CONCLUSIONS: In younger patients with thoracolumbar burst fractures who undergo posterior surgical stabilization, planned implant removal results in superior functional outcomes without significant difference in kyphotic angle correction loss compared to implant retention.

Reversible cerebral vasoconstriction syndrome associated with hyperosmolar hyperglycaemic state: A case report and literature review.

Reversible cerebral vasoconstriction syndrome (RCVS) is an uncommon disorder characterised by thunderclap headache and self-resolving angiographic vasospasm in the presence or absence of neurological deficit. We present the first case of RCVS likely precipitated by a complex array of confounding factors including a hyperosmolar hyperglycaemic state (HHS), induction chemotherapy with cyclophosphamide, non-Hodgkin's lymphoma, pancytopenia and previous blood transfusions. However, the clinical presentation in this case of altered conscious state followed by thunderclap headache was highly suggestive of HHS being the crucial inciting factor. This report of RCVS associated with HHS lends unique insight into key underlying pathophysiological mechanisms, and warns of the need to maintain a high index of suspicion for this elusive condition given the dynamic and transient nature of its clinical and radiological features.

Bilobed intramedullary and extramedullary bronchogenic cyst of the conus medullaris: illustrative case.

BACKGROUND: Spinal bronchogenic cysts are rare nonneoplastic congenital variants of neurenteric cysts. The natural history and surgical management of these lesions are poorly understood. OBSERVATIONS: A 25-year-old male presented with progressive back pain and bilateral lower limb sciatica of 6 months' duration. He had undergone subtotal resection of an intramedullary bronchogenic conus medullaris cyst 5 years prior. Magnetic resonance imaging revealed a recurrent bilobed intramedullary and extramedullary conus medullaris cystic lesion. The authors resected the lesion via a posterior approach with the aid of intraoperative neuromonitoring. Gross total resection was precluded by the tightly adherent nature of the cyst and the fact that stimulation of a residual intramedullary portion of the lesion evoked external anal sphincter responses. LESSONS: This is the first reported case of a bilobed intramedullary and extramedullary bronchogenic cyst of the conus medullaris. This unique case lends insight into the poorly defined embryogenesis of bronchogenic cysts by favoring the split notochord syndrome theory rather than the ectopic ectoderm proposal. The importance of neuromonitoring when resecting these tightly adherent lesions is demonstrated. Finally, although the secretory nature of these lesions portends a tendency for cyst reaccumulation, it is imperative to recognize that this is usually a slow process.

The Role of Spinal Orthoses in Osteoporotic Vertebral Fractures of the Elderly Population (Age 60 Years or Older): Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: Spinal orthoses have been generally used in the management of osteoporotic vertebral fractures in the elderly population with purported positive biomechanical and functional effects. To our knowledge, this is the first systematic review of the literature examining the role of spinal orthoses in osteoporotic elderly patients who sustain low energy trauma vertebral fractures. METHODS: A systematic literature review adherent to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. Methodical searches utilizing MEDLINE, EMBASE, Google Scholar, and Cochrane Databases was performed. RESULTS: Of the 2019 articles initially retrieved, 7 published articles (4 randomized controlled trials and 3 prospective cohort studies) satisfied the inclusion criteria. Five studies reported improvement in quantitative measurements of spinal column stability when either a rigid or semirigid orthosis was used, while 1 study was equivocal. The studies also showed the translation of biomechanical benefit into significant functional improvement as manifested by improved postural stability and reduced body sway. Subjective improvement in pain scores and quality of life was also noted with bracing. CONCLUSION: The use of spinal orthoses in neurologically intact elderly patients aged 60 years and older with osteoporotic compression vertebral fractures results in improved biomechanical vertebral stability, reduced kyphotic deformity, enhanced postural stability, greater muscular strength and superior functional outcomes.

Intracranial peripherally enhancing lesions in cardiac transplant recipients: A rare case series and literature review.

Intracranial peripherally enhancing lesions in immunosuppressed solid organ transplant recipients represent a unique diagnostic and management dilemma due to the vast array of differentials that demand consideration. Diagnosis of the underlying pathology is often guided by the use of magnetic resonance imaging (MRI). We present the first published case series of three cardiac transplant recipients with significantly atypical neuroradiological findings contrary to the tenets of contemporary literature. Our rare case series consists of: (1) A sterile Mycobacterium pyogenic abscess mimicking glioblastoma multiforme due to an immunosuppressed state (2) Epstein Barr Virus encephalitis masquerading as Central Nervous System Post-Transplant Lymphoproliferative Disorder (3) An unusual case of partially treated disseminated Nocardiosis warning of the need to consider the immunosuppressed state and partial treatment response obfuscating classical MRI appearances. We utilise these unprecedented cases as the basis of a literature review to understand the pathophysiology behind the peculiar imaging findings in this rarefied cohort of transplant recipients, and rationalise why the MRI findings in each instance contradicts the accepted imaging patterns. In the setting of potential unreliability of neuroradiology in this immunosuppressed unique subgroup, we hope to impart to clinicians that definitive diagnosis obtained by emergent neurosurgical intervention may be necessary to accurately and expediently guide further medical management.

Metastatic craniocervical hemangiopericytoma presenting with hydrocephalus and papilledema - Case review.

Hemangiopericytomas are rare mesenchymal tumors with propensity to recur locally and metastasize. We report the unique case of a fifty-five-year-old male with recurrence of a previously resected craniocervical hemangiopericytoma presenting with obstructive hydrocephalus secondary to new metastatic cerebellar deposits. Emergent surgical resection of the cerebellar hemangiopericytomas was performed prior to adjuvant radiotherapy. Hemangiopericytomas are rare but important differentials for craniocervical junction lesions. Gross total resection remains the cornerstone of management with post-operative radiotherapy and chemotherapy as potential adjuncts. Tumors located in deep regions pose complex management challenges as safe maximal excision may be limited by proximal eloquent structures.