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.

Spinal extradural arachnoid cyst: A rare cause of thoracic myelopathy.

A spinal extradural arachnoid cyst (SEAC) is a rare condition which can lead to back pain, radiculopathy, and compressive myelopathy. It accounts for approximately 1% of spinal tumours. The exact aetiology of SEACs is not well understood; however, this study is supportive of a traumatic aetiology of this disease in addition to supporting a uni-directional valve as a mechanism of CSF accumulation. The purpose of this study is to review the presentation, work-up, treatment and postoperative course of a patient with SEAC. We present the case of a 40-year-old male with a history of trauma who developed a SEAC and was treated surgically at our unit. Although a rare disease, we highlight the importance of early diagnosis and surgical treatment as it is a surgically curable disease with a good postoperative prognosis.

Endodermal Cyst Arising from the Oculomotor Nerve: A Case Report Outlining the Novel Insertion of Cysto-subarachnoid Shunt for Refractory Disease.

BACKGROUND: Endodermal cysts of the oculomotor nerve are rare presentations. Only case reports are available to help guide clinicians with managing this rare entity. CASE DESCRIPTION: A 3-year-old boy presented with an acute on chronic left oculomotor nerve palsy due to a left interpeduncular cistern cyst found on magnetic resonance imaging. He underwent a left pterional craniotomy and fenestration of the histologically proven endodermal cyst and had initial improvement at the 2-month review. He subsequently developed clinical and radiologic evidence of recurrence and was treated surgically with a refenestration and insertion of a cysto-subarachnoid shunt through a trans-sylvian approach. At 6-month follow-up, there was complete resolution of the oculomotor nerve palsy with interval development of oculomotor synkinesis. CONCLUSIONS: Magnetic resonance imaging is an essential modality in the follow-up of these patients postoperatively in the setting of unchanged or deteriorated neurology. Fenestration of the cyst is appropriate first-line surgical management; however, a cysto-subarachnoid shunt is a safe consideration in recurrent, symptomatic cysts and provides sustained symptom resolution.

Restoring spinopelvic harmony with lateral lumbar interbody fusion: is it a realistic goal?

BACKGROUND: The importance of spinopelvic harmony [pelvic incidence (PI) = lumbar lordosis (LL) ±10 degrees] is well established in the literature. We aimed to determine whether lateral lumbar interbody fusion (LLIF) surgery in isolation is successful in restoring spinopelvic harmony, and whether the surgery maintained the relationship in those who present in a balanced state. METHODS: A retrospective radiographic analysis was performed on patients who underwent LLIF surgery, followed by posterior instrumented fusion, between January 2012 to August 2019 by a single surgeon (AD). Pre- and post-operative X-rays were reviewed by two authors using Surgimap spinal imaging 2.2.15.5. The LL, PI, and PI-LL mismatch, as well as a range of coronal and segmental sagittal radiographic parameters, were recorded. RESULTS: A total of 71 patients with 170 levels treated via LLIF were analysed. A mean pre-operative PI-LL of 14.3 degrees and post-operative value of 13.4 degrees was recorded (P=0.43). Of the 41 patients who were imbalanced pre-operatively, 13 (31.7%) were restored to a LL within 10 degrees of PI post-LLIF procedure. 30 patients presented in spinopelvic harmony, and 25 (83.3%) of those maintained that relationship following LLIF. Mean coronal global Cobb angles (13.7 degrees pre-operatively to 7.7 degrees post-operatively), segmental coronal Cobb angles (3.8 to 0.9 degrees), and anterior (5.2 to 9.8 mm) and posterior (3.2 to 6.7 mm) disc heights all improved significantly post-LLIF surgery (P<0.0001). CONCLUSIONS: Although an effective treatment for coronal deformities and providing indirect decompression for degenerative lumbar disc disease, LLIF surgery alone is unlikely to result in correction of sagittal deformity and in particular spinopelvic harmony.

Interobserver Reliability of Spinal Adverse Events Severity System - Neuro (SAVES-N): A Prospective Adverse Event Reporting System for Neurosurgical Cases.

BACKGROUND: The reporting of adverse events (AEs) in neurosurgery uses inconsistent definitions and subjective grading systems. A standardized system for recording and describing AEs would allow valid comparisons to be drawn between different institutions, using different technologies, at different times. The Spinal Adverse Events Severity System - Neuro (SAVES-N) system is a modification of the well-validated SAVES-V2 system that encompasses complications from both cranial and spinal surgery. The objective of this study was to assess the interobserver reliability of SAVES-N in spinal and cranial neurosurgery. METHODS: Ten vignettes, including cranial and spinal neurosurgical cases, were assessed by groups of consultant neurosurgeons (n = 5) and neurosurgical registrars (n = 5) using the SAVES-N system. Interobserver reliability for the presence of AEs, the type of AE, and the SAVES severity grade of the AE were calculated using Gwet's AC2 and Fleiss' kappa and were interpreted using the thresholds described by Landis and Koch. RESULTS: Neurosurgeons had almost-perfect agreement (Gwet AC2 = 0.93), whereas registrars had substantial agreement (Gwet's AC2 = 0.74) in determining the presence or absence of AEs. Both neurosurgeons (Fleiss' kappa = 0.78) and registrars (Fleiss' kappa = 0.70) demonstrated substantial agreement within their groups as to the type of AE. Similarly, neurosurgeons (Gwet's AC2 = 0.94) and registrars (Gwet's AC2 = 0.81) both graded the severity of the AE with almost perfect agreement. CONCLUSIONS: The results of this study demonstrate that the scope of the well-validated SAVES-V2 system may be broadened to cranial neurosurgical cases by SAVES-N with substantial to almost-perfect interobserver reliability.

Unruptured Paraclinoid Aneurysm Treatment Effects on Visual Function: Systematic Review and Meta-analysis.

OBJECTIVE: Postoperative visual outcomes following repair of unruptured paraclinoid aneurysms (UPAs) are not well defined. We aim to investigate the influence of treatment modality on visual function. METHODS: A systematic literature analysis using the Ovid Medline and EMBASE databases was performed, encompassing English language studies (published between 1996 and 2016) reporting treatment outcomes for UPAs. Rates of visual morbidity (new, permanent postoperative deficit, worsening preoperative deficit); angiographic (occlusion, recurrence, retreatment) and clinical outcomes (death, disability, post-treatment subarachnoid hemorrhage) were recorded. Random effects meta-analysis was performed. RESULTS: Twenty-eight studies reported visual outcomes, with data for 1013 endovascular and 691 microsurgical patients. In patients with normal vision undergoing elective repair of UPAs, rates of postoperative visual morbidity were higher following microsurgical (10.8%; 95% confidence interval [CI] 8.5-13.7) than endovascular (2.0%; 95% CI 1.2-3.2) interventions, P < 0.001. In those presenting with preoperative visual impairment, surgery was associated with a modest advantage in visual recovery compared with endovascular therapies (65.2% vs. 48.9%, P < 0.03). There were no differences in visual morbidity following treatment with any of the endovascular modalities. Meta-analysis of comparative studies suggested a trend toward poor visual (ES = 0.42; 95% CI 0.08-2.09) and clinical outcomes (ES = 0.57; 95% CI 0.07-4.44) following microsurgery and a trend toward angiographic recurrence (ES = 2.52; 95% CI 0.80-7.90) and retreatment (ES = 1.62; 95% CI 0.46-5.67) after endovascular interventions. CONCLUSION: In patients with normal vision undergoing repairs for UPAs, there is a positive correlation between visual outcomes and endovascular treatments. When visual compromise is present, surgery provided modest advantage in visual recovery. However, definitive conclusions were not possible due to data heterogeneity.

Ependymoma in adults: Local experience with an uncommon tumour.

This study reviews our tertiary hospital experience in an adult population of ependymoma patients. Ependymomas are uncommon tumours of the central nervous system (CNS) and the literature provides little information to guide management and predict prognosis. The prospectively maintained Australian Comprehensive Cancer Outcomes and Research Database of CNS tumours was searched for patients diagnosed with ependymomas at the Royal Melbourne Hospital between January 2008 and December 2013. A total of 39 adult patients with ependymoma were identified, including 13 with spinal myxopapillary ependymoma. The mean age at diagnosis was 44 years. All patients underwent surgical resection, 67% of whom had a gross macroscopic resection. Postoperative adjuvant radiotherapy was administered to 11 patients (30%), two (5%) died from progressive disease and seven (18%) developed recurrent disease. Our findings are consistent with the existing literature for patient demographics and the approach to treatment, whilst our clinical outcomes appear more favourable. This study provides the basis for further and necessary research, including determination of the molecular characterisation of these tumours and the identification of prognostic and predictive biomarkers and treatment targets.

Conservative management of spontaneous bile duct perforation in infancy:: case report and literature review.

Spontaneous bile duct perforation in infants is rare, with less than 150 cases having been reported worldwide. With a highly variable presentation, diagnosis and treatment can prove challenging, and outcomes are not without significant morbidity. We herewith report the case of an 8-week-old male infant with spontaneous bile duct perforation. He initially presented with abdominal sepsis and septated ascites on ultrasound, which was confirmed as bilious on ascitic tap and at diagnostic laparoscopy. Intraoperative cholangiogram demonstrated a localized leak at the junction of the cystic and common bile duct. Conversion to laparotomy was ultimately required with cholecystostomy, and 2 external intraabdominal drains were placed. He was subsequently managed conservatively with 4 weeks external drainage, with a repeat cholangiogram at 6 weeks, demonstrating successful resolution of the leak. The reported case supports the findings of changing practices in the existing literature. We suggest that, in cases of spontaneous bile duct perforation with no distal obstruction, dissection and surgery to the biliary tree are not always required. Conservative management with simple external drainage can have its complications but, as shown here, can be a successful treatment option in terms of healing of perforation.