Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis.

PURPOSE: Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed. METHODS: This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test. RESULTS: Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5. CONCLUSIONS: This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

Endoscopic third ventriculostomy in hydrocephalus patients with functioning ventriculoperitoneal shunts: challenging the dictum that shunts treat all types of hydrocephalus. Patient series.

BACKGROUND: Although ventriculoperitoneal shunting is standard for hydrocephalus, shunting may not be ideal for aqueductal stenosis. A cohort of patients with aqueductal stenosis displayed symptoms of over- and underdrainage, despite a patent ventriculoperitoneal shunt (VPS) and optimized valve settings. Endoscopic third ventriculostomies (ETVs) were performed in a subset of these patients with successful treatment of their underlying hydrocephalus, despite a functioning shunt. OBSERVATIONS: All patients who had undergone ETV with a history of ventriculoperitoneal shunting were retrospectively reviewed. Patients experiencing over- or underdrainage symptoms despite a patent shunt were included. Cerebral aqueduct anatomy and third ventricle bowing were reviewed on preoperative imaging. Seven patients met the study criteria. All showed cerebral aqueductal stenosis and third ventricle bowing. After ETV, all patients demonstrated decreased third ventricle bowing and clinical improvement without the need for secondary cerebrospinal fluid (CSF) diversion. LESSONS: Despite a functioning VPS, patients with aqueductal stenosis may not be adequately treated. The underlying reasons are not clearly understood but suggest abnormal CSF dynamics due to aberrant parenchymal compliance. The authors theorize that ETV can more effectively treat these patients. ETV can be considered a viable treatment option in aqueductal stenosis despite a patent VPS, challenging the traditional teaching that shunts ideally treat all types of hydrocephalus.

Post-operative antibiotic prophylaxis in spine surgery patients with thoracolumbar drains: A meta analysis.

Objective: Closed-suction drains are commonly placed after thoracolumbar surgery to reduce the risk of post-operative hematoma and neurologic deterioration, and may stay in place for a longer period of time if output remains high. Prolonged maintenance of surgical site drains, however, is associated with an increased risk of surgical site infection (SSI). The present study aims to examine the literature regarding extended duration (≥24 h) prophylactic antibiotic use in patients undergoing posterior thoracolumbar surgery with closed-suction drainage. Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Relevant studies reporting the use of 24-h post-operative antibiotics compared with extended duration post-operative antibiotics in patients undergoing posterior thoracolumbar surgery with closed-suction drainage were identified from a PubMed database query. Results: Six studies were included for statistical analysis, encompassing 1003 patients that received 24 h of post-operative antibiotics and 984 patients that received ≥24 h of post-operative antibiotics. The SSI rate was 5.16 % for the shorter duration group (24 h) and 4.44 % (p = 0.7865) for the longer duration group (≥24 h). Conclusions: There is no significant difference in rates of SSI in patients receiving 24 h of post-operative antibiotics compared with patients receiving ≥24 h of post-operative antibiotics. Shorter durations of post-operative antibiotics in patients with thoracolumbar drains have similar outcomes compared to patients receiving longer courses of antibiotics. Shorter durations of antibiotics could potentially help lead to lower overall cost and length of stay for these patients.

Nonoperative Management in Intact Burst Fracture Patient With Thoracolumbar Injury Classification and Severity Score of 5: A Case Report.

Thoracolumbar fractures are a common consequence of trauma, often a result of motor vehicle accidents or falls. Burst fractures are a morphology of thoracolumbar fracture in which compressive force causes retropulsion of the posterior elements of the vertebral body, potentially leading to neurological deficits. The Thoracolumbar Injury Classification and Severity (TLICS) score is a decision-making tool to help surgeons decide between nonoperative and operative management. For assigned scores of 4, management is at the discretion of the surgeon, and for scores ≥ 5, operative treatment is recommended. Burst fracture patients that are neurologically intact are given a score of 5 if there is a posterior ligamentous complex (PLC) injury and are recommended to undergo operative management. Here we present a neurologically intact patient with an L4 burst fracture with PLC injury that was managed conservatively and demonstrated successful clinical, functional, and radiographic recovery.

A Rare Third Ventricular Dermoid Cyst in an Adult With Imaging Characteristics Consistent With a Colloid Cyst.

A 64-year-old male presented with spontaneous intracerebral hemorrhage and obstructive hydrocephalus without evidence of a third ventricular mass in 2019. The patient was lost to follow-up and re-admitted one year later for hydrocephalus secondary to a third ventricular mass. Imaging characteristics were consistent with a colloid cyst, which was the presumptive diagnosis. A transcallosal transchoroidal approach was utilized for cyst resection. The cyst wall was carefully incised, releasing flakey, partially solid contents which were grossly inconsistent with a colloid cyst. Due to the concern of iatrogenic cyst rupture in the setting of unknown diagnosis, the patient was placed on steroids post-operatively. Surgical specimens sent at the time of surgery were consistent with dermoid cyst. We present the first reported case of a third ventricular dermoid cyst in an adult initially misdiagnosed as a colloid cyst based on imaging characteristics.

Skeletal muscle mass as a marker to predict outcomes in children and young adults with cancer.

PURPOSE: Nutrition is an important outcome predictor in oncology patients including treatment response, physical disability, quality of life, and overall survival. Sarcopenia (loss of skeletal muscle mass and function) is a demonstrated marker of nutritional status in adults, but data are more limited in children. The purpose of this study was to evaluate whether total psoas muscle area (tPMA) measured at the time of cancer diagnosis predicts overall survival (OS), disease free survival (DFS), or number of days neutropenic. METHODS: A retrospective study was performed. tPMA was measured at the L3 and L4 mid-lumbar vertebral body level by a single reviewer on cross-sectional imaging studies performed within 2 weeks of primary oncologic diagnosis for all oncology patients who received their primary therapy at Cincinnati Children's Hospital between 1/1/2000 and 12/31/2013. Spearman's correlation was used to assess the association between tPMA and OS, DFS, days neutropenic, and adjusted days neutropenic. Subanalysis was performed assessing the relationship of tumor type and age at diagnosis with each parameter. RESULTS: 164 patients (median age 9.9 years; 89 M/75 F) were included in the study. Days neutropenic and normalized days neutropenic were significantly but weakly negatively correlated with tPMA at L3 (r = - 0.24, p < 0.002 and r = - 0.18, p < 0.05 respectively) and L4 (r = - 0.25, p < 0.002; and and r = - 0.19, p < 0.02 respectively). At subanalysis, the correlation between anthropometric features and normalized days neutropenic was only seen with brain tumors. There was no statistically significant relationship between sarcopenia at diagnosis and DFS or OS overall or in subanalysis. CONCLUSION: There is a weak inverse relationship between days neutropenic and psoas muscle bulk in pediatric and young adult oncology patients suggesting a relationship between nutritional status and cell recovery. Measures of sarcopenia, however, did not correlate with DFS or OS.

Roadmap to Ventral Craniocervical Junction Through the Endonasal Corridor: Anatomic Evaluation of Inverted U-Shaped Nasopharyngeal Flap Exposure in a Cadaveric Study.

BACKGROUND: There is a paucity of data in the literature describing quantitative exposure of the ventral craniocervical junction through the endonasal corridor in a safe manner mindful of locoregional anatomy. OBJECTIVE: To quantify ventromedial exposure of O-C1 and C1-2 articular structures after turning an inverted U-shaped nasopharyngeal flap (IUNF) and to obtain measurements assessing the distance of flap margins to adjacent neurovascular structures. METHODS: In 8 cadaveric specimens, an IUNF was fashioned using a superior incision below the level of the pharyngeal tubercule of the clivus and lateral incisions in the approximate region of Rosenmuller fossae bilaterally. Measurements with calipers and/or neuronavigation software included flap dimensions, exposure of O-C1 and C1-2 articular structures, inferior reach of IUNF, and proximity of the internal carotid artery (ICA) and hypoglossal nerve to IUNF margins. RESULTS: The IUNF facilitated exposure of an average of 9 mm of the medial surfaces of the right/left O-C1 joints without transgression of the carotid arteries or hypoglossal nerves. The C1-2 articulation could not be routinely accessed. The margins of the IUNF were not in close (<5 mm) proximity to the ICA in any of the 8 specimens. In 6 of 8 specimens, the dimensions of the IUNF were in close (<5 mm) horizontal or vertical proximity to the hypoglossal foramina. CONCLUSION: The IUNF provided safe and reliable access to the medial O-C1 articulation. Given the close proximity of the exocranial hypoglossal foramen, neuronavigation assistance and neuromonitoring with attention to the superolateral IUNF margin are recommended.

The Impact of C1 Anterior Arch Preservation on Spine Stability After Odontoidectomy: Systematic Review and Meta-Analysis.

BACKGROUND: Odontoidectomy for symptomatic irreducible ventral brainstem compression at the craniovertebral junction may result in spine instability requiring subsequent instrumentation. There is no consensus on the importance of C1 anterior arch preservation in prevention of iatrogenic instability. We conducted a systematic review of the impact of C1 anterior arch preservation on postodontoidectomy spine stability. METHODS: PubMed, Embase, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies of patients undergoing odontoidectomy. Random-effect model meta-analyses were performed to compare spine stability between C1 anterior arch preservation versus removal and posttreatment outcomes between transoral approaches (TOAs) versus endoscopic endonasal approaches (EEAs). RESULTS: We included 27 studies comprising 462 patients. The most common lesions were basilar invagination (73.3%) and degenerative arthritis (12.6%). Symptoms included myelopathy (72%) and neck pain (43.9%). Odontoidectomy was performed through TOA (56.1%) and EEA corridors (34.4%). The C1 anterior arch was preserved in 16.7% of cases. Postodontoidectomy stabilization was performed in 83.3% patients. Median follow-up was 27 months (range, 0.1-145). Rates of spine instability were significantly lower (P = 0.004) when the C1 anterior arch was preserved. Postoperative clinical improvement and pooled complications were reported in 78.8% and 12.6% of patients, respectively, with no significant differences between TOA and EEA (P = 0.892; P = 0.346). Patients undergoing EEA had significantly higher rates of intraoperative cerebrospinal fluid leaks (P = 0.002). CONCLUSIONS: Odontoidectomy is safe and effective for treating craniovertebral junction lesions. Preservation of the C1 anterior arch seems to improve maintenance of spine stability. TOA and EEA show comparable outcomes and complication rates.

Risk of Infection Associated with Transmucosal Placement of Instrumentation in Clean-Contaminated Field: Systematic Analysis.

Instability of the craniovertebral junction (CVJ) following odontoidectomy is relatively common. Traditionally, separate stage posterior atlantoaxial ± occipitocervical fusion is used for treatment. A transmucosal approach using a clean-contaminated route is associated with hypothetical risks of infectious complications. There is a paucity of information in the literature assessing the risk of surgical site infection (SSI) using the transmucosal approach for hardware placement. The authors conducted a literature search through PubMed identifying patients with pathology requiring transmucosal (i.e., transnasal or transoral) CVJ fixation. Studies that described 1) cases requiring a transmucosal approach and 2) associated infectious complications were included. Rates of SSIs, device removal, unplanned reoperation, and hardware failures were analyzed. Descriptive statistics and odds ratios (ORs) were used to compare complications. Nine studies with a total of 431 patients were identified. There were 4 (0.93%) superficial SSIs and 4 (0.93%) deep SSIs. In total, 1.86% of patients experienced SSI. There were 18 (4.18%) cases of unplanned reoperation, 4 (0.93%) related to SSI. Five (1.16%) patients required removal of their anterior fixation device, 4 (0.93%) related to SSI. ORs comparing our results with Medvedev et al's retrospective National Surgical Quality Improvement Program study assessing the risk associated with posterior cervical fixation showed no statistical difference between postoperative infection rates (OR = 0.72, P = 0.36). An extensive review of the literature found no evidence to suggest placement of spinal hardware via transmucosal corridor is associated with an increased risk of SSI.