Case Series of Tubular Retractor Assisted Minimally Invasive Extraforaminal L5/S1 Microdiskectomy.

BACKGROUND: We present the largest series of tubular assisted minimally invasive extraforaminal L5/S1 microdiskectomy and describe the operative nuances. An extraforaminal L5/S1 disk herniation poses a surgical challenge as a result of limited access from a high iliac crest, the sacral ala, and the large transverse process of L5 necessitating oblique working angles. METHODS: This is a case series of 28 consecutive patients who underwent tubular retractor-assisted minimally invasive extraforaminal L5/S1 microdiskectomy between 2017 and 2020 for L5 radiculopathy. Preoperative variables include demographics (age, gender); imaging characteristics (presence of spondylolisthesis, grade and presence of dynamic instability); and patient-reported measures of pain and function. Postoperatively, any complications, pain, and function were documented at 1-day, 3-month, and 12-months follow-up. Statistical analysis involved descriptive analysis of measured variables. RESULTS: Patients (13 females and 15 males) had a median age of 62 years (range: 32-92). One patient demonstrated grade I spondylolisthesis with no dynamic instability. Twenty-six patients (93%) achieved complete pain resolution during the follow-up period. Two patients had persistent or recurrent radicular pain, 1 of whom resolved completely with a redo tubular retractor-assisted minimally invasive microdiskectomy. No other complications were noted during the postoperative follow-up. CONCLUSIONS: Tubular retractor-assisted minimally invasive extraforaminal L5/S1 microdiskectomy is an effective approach. Good surgical outcomes are achieved while avoiding the complications associated with more invasive options such as open surgery or fusion.

Intraoperative MRI in trans-sphenoidal surgery using frameless stereotaxis.

BACKGROUND: Intraoperative magnetic resonance imaging (iMRI) has been used for pituitary surgery for approximately 20 years. The introduction of frameless stereotaxis allows efficient navigation for both the ENT and neurosurgeon. This allows flexibility in placement of the patients head to facilitate resection, efficient use of theater time and improves the safety profile of the operation. This is the first study to describe and investigate the use of frameless stereotaxis in conjunction with iMRI. METHODS: Consecutive patients who underwent iMRI guided trans-sphenoidal debulking using frameless stereotaxis over a 3-year period, from January 2016 to June 2019, were included in this case series and reviewed retrospectively. The use of AxiEM (Medtronic, USA) tracker facilitated frameless stereotaxis in conjunction with iMRI for trans-sphenoidal debulking of sellar lesions based on the "twin-operating" model. RESULTS: The cohort of 47 patients had a mean age of 55 years with a slight female predilection. The average lesion size measured 20 mm (3-46 mm) in maximal diameter with objective evidence of visual deterioration being the most common indication to consider surgery. The use of iMRI identified two patients with suboptimal decompression facilitating further resection in the same anesthetic and one hemorrhagic complication requiring evacuation and hemostasis to reduce postoperative morbidity. CONCLUSION: This study describes the procedural nuances in the use of frameless stereotaxis for iMRI in transsphenoidal surgery to further reduce morbidity and improve outcomes, as well as improving theater utilization and reducing cost.

Case Report of an Anterior Thoracic Myelomeningocele: A Multidisciplinary Approach to Surgical Management.

BACKGROUND: Cervicothoracic myelomeningocele (MMC) is a rare entity with only 2 reported cases in the literature of anterior thoracic MMC. CASE DESCRIPTION: We report a third case in a 3-year-old boy. MMC was diagnosed during antenatal screening and later warranted surgical intervention. Despite being asymptomatic, radiologic surveillance demonstrated worsening syringomyelia, tonsillar descent, and cord signal change concerning for myelomalacia. Preoperative management involved respiratory assessment for pulmonary compromise, general pediatric consultation, gait analysis by physiotherapy, and serial imaging by radiology. Surgical management involved an anterior thoracotomy approach by cardiothoracic surgeons, repair of the MMC by neurosurgeons, and bone graft to ameliorate the bony defect in the vertebral body by orthopaedic surgeons. Postoperative care involved 4 days in the intensive care unit and 14 days on the pediatric neurosurgical ward. At 3-year follow-up, there was radiologic improvement of syringomyelia, tonsillar descent, and kyphoscoliosis with no neurological or pulmonary complications. CONCLUSIONS: This case highlights the unique multidisciplinary surgical management of the rare entity of anterior thoracic MMC without scoliosis correction for radiologic progression.

An Australian Response to the COVID-19 Pandemic and Its Implications on the Practice of Neurosurgery.

OBJECTIVE: This study was designed to assess the impact of public health policy in Australia in response to the coronavirus disease identified in 2019 (COVID-19) pandemic on the delivery of neurosurgical services. Being essential services, we postulated that there would not be a decrease in elective and emergency neurosurgical presentations and surgeries. METHODS: This is a prospective, observational, epidemiologic study in strict adherence to the "STROBE" (Strengthening The Reporting of OBservational studies in Epidemiology) guidelines. It is a cross-sectional, multicentric study involving 5 tertiary neurosurgical centers to capture all public neurosurgical admissions in Queensland during the past 3 months (February-April, 2020) of significant public health policy changes to combat COVID-19. RESULTS: An analysis of the 1298 admissions for the Queensland population of 5.07 million Australians demonstrated a decrease in the number of elective and emergency admissions. The decline in elective admissions, particularly degenerative spine, benign neoplasms, and vascular pathologies, was a direct response of government strategy to curb activity to urgent surgical interventions only. Moreover, a trend toward fewer emergency admissions was also noted, partly explained by less trauma and also a decline in vascular pathologies including subarachnoid hemorrhage. CONCLUSIONS: In comparison with Europe and North America, this study demonstrates the impact of proactive public health measures in Australia that successfully flattened the COVID-19 curve while facilitating ongoing care of acutely unwell neurosurgical patients.

Influence of sagittal plane component alignment on kinematics after total knee arthroplasty.

PURPOSE: Knee kinematics is pivotal to patient satisfaction and functional ability after total knee arthroplasty (TKA). The aim of this study is to examine the influence of sagittal plane component alignment as defined by femoral component angle (FCA), tibial slope (TS) and posterior condylar offset (PCO) on knee kinematics as defined by maximum extension angle (MEA), maximum flexion angle (MFA) and range of motion (ROM) after TKA. METHODS: This is a prospective, cross-sectional study of 105 osteoarthritic knees that underwent primary cruciate retaining TKA using a single implant design at a single tertiary institution. The sagittal plane component alignment was measured on weight-bearing true lateral radiographs taken day one post-operation and knee kinematics measured using a goniometer 1 year after TKA by the primary investigator. RESULTS: Although the MFA was influenced by gender (P = 0.04); age, gender and pre-operative kinematics did not otherwise influence post-operative knee kinematics. The prediction model for MFA was statistically significant (P = 0.03) and accounted for 8.4 % of the variance. FCA (r = 0.3, P = 0.01) and PCO (r = 0.2, P = 0.05) demonstrated a statistically significant correlation with MFA. However, the prediction models for ROM and MEA did not achieve statistical significance. FCA (r = 0.2, P = 0.02) demonstrated a statistically significant correlation with ROM. CONCLUSION: The most important findings of this study are that the FCA demonstrates weak positive correlation with MFA and ROM and that PCO demonstrates weak positive correlation with MFA. However, TS does not contribute significantly to knee kinematics after TKA. This is clinically relevant as orthopaedic surgeons can increase the PCO in cruciate retaining TKA and the FCA within therapeutic limits to improve knee kinematics. LEVEL OF EVIDENCE: II.

Pachymeningeal enhancement-a comprehensive review of literature.

Pachymeningeal enhancement, synonymous with dural enhancement, is a radiological feature best appreciated on a contrast-enhanced magnetic resonance imaging (MRI). The vasculature of the dura mater is permeable, facilitating avid uptake of contrast agent and subsequent enhancement. Thin, discontinuous enhancement can be normal, seen in half the normal population. In patients complaining of postural headaches worse on sitting, gadolinium-enhanced MRI findings of diffuse pachymeningeal enhancement is highly suggestive of benign intracranial hypotension. In these cases, the process of pachymeningeal enhancement is explained by the Monro-Kellie doctrine as compensatory volume changes by vasocongestion and interstitial oedema of the dura mater due to decreased cerebrospinal fluid (CSF) pressure. Focal and diffuse pachymeningeal enhancement can also be attributed to infectious or inflammatory, neoplastic and iatrogenic aetiologies. Correction of the underlying pathology often results in spontaneous resolution of the pachymeningeal enhancement. There have also been reports of pachymeningeal enhancement associated with cerebral venous sinus thrombosis, temporal arteritis, baroreceptor reflex failure syndrome and arteriovenous fistulae.

Carcinoma ex pleomorphic adenoma: a comprehensive review of clinical, pathological and molecular data.

Carcinoma ex pleomorphic adenoma (Ca ex PA) is a carcinoma arising from a primary or recurrent benign pleomorphic adenoma. It often poses a diagnostic challenge to clinicians and pathologists. This study intends to review the literature and highlight the current clinical and molecular perspectives about this entity. The most common clinical presentation of CA ex PA is of a firm mass in the parotid gland. The proportion of adenoma and carcinoma components determines the macroscopic features of this neoplasm. The entity is difficult to diagnose pre-operatively. Pathologic assessment is the gold standard for making the diagnosis. Treatment for Ca ex PA often involves an ablative surgical procedure which may be followed by radiotherapy. Overall, patients with Ca ex PA have a poor prognosis. Accurate diagnosis and aggressive surgical management of patients presenting with Ca ex PA can increase their survival rates. Molecular studies have revealed that the development of Ca ex PA follows a multi-step model of carcinogenesis, with the progressive loss of heterozygosity at chromosomal arms 8q, then 12q and finally 17p. There are specific candidate genes in these regions that are associated with particular stages in the progression of Ca ex PA. In addition, many genes which regulate tumour suppression, cell cycle control, growth factors and cell-cell adhesion play a role in the development and progression of Ca ex PA. It is hopeful that these molecular data can give clues for the diagnosis and management of the disease.