Neurogenic pulmonary edema.

AIM: We report a case of neurogenic pulmonary edema in a patient who sustained a severe traumatic brain injury in a motorbike accident and review the current literature with regards to the management of neurogenic pulmonary edema (NPE). METHODS: A 17 year old male was involved in a motorbike collision into a tree. Copious amounts of pink frothy sputum was noted on scene. Rapid sequence intubation was performed on scene and video laryngoscopy demonstrated profuse frothy secretions welling up from the larynx. RESULTS: The patient underwent emergency external ventricular drain insertion for intracranial pressure (ICP) monitoring. Intracranial pressures remained refractorily high and a decompressive bifrontal craniectomy was performed on the subsequent day. He was tracheostomised on admission day 24 and discharged from ICU on day 34. DISCUSSION: Neurogenic pulmonary edema is defined as acute respiratory distress triggered by severe sympathetic discharge from acute compromise in the central nervous system. Rapid intervention with intubation is often necessary to protect the airways and facilitate diagnostic evaluation. Reduction of ICP and supportive mechanical ventilation to improve oxygenation is necessary. Positive end-expiratory pressure should be carefully applied to balance recruitment of alveoli and minimisation of ICP. Although NPE is estimated to resolve within 72 h in more than half of patients, prognosis is generally poor due to the severity of the underlying brain injury, with estimated mortality rates of between 60 and 100%. CONCLUSION: Neurogenic pulmonary edema is a potentially life-threatening complication of severe brain injury and should be recognised early to facilitate management.

Mechanical and Geometric Analysis of Fenestration Design for Polymethylmethacrylate-Augmented Pedicle Screw Fixation.

BACKGROUND: The practice of cement augmentation in pedicle screw fixation is well established. However, there is a lack of consensus regarding the optimal screw design or cement type. This remains a clinically important question given the incidence of cement augmentation-associated complications. While fenestrated screws have become widely used in clinical practice, the relationship between fenestration placement along the screw axis and cement plume geometry and pullout strength have yet to be clarified. This study was designed to evaluate the mechanical and geometric properties of different fenestrated screw designs and cement viscosities in pedicle screw fixation. METHODS: Three different screw fenestration configurations and 2 different cement viscosities were examined in this study. Axial pullout tests were conducted in both foam blocks and cadaveric vertebrae. All vertebral specimens underwent tests of bone mineral density. In the foam blocks, 6 tests were conducted for each augmentation combination and also for nonaugmented controls. In the cadaveric testing, 36 lumbar vertebrae were instrumented with a cemented and uncemented control screw to compare features of fixation. Computed tomography (CT) images were taken to assess the geometric profile of the cement plumes in both the foam blocks and the cadaveric vertebrae. RESULTS: In both foam blocks and vertebral specimens, cementation was shown to confer a significant increase in pullout strength. Significant correlations existed between the anterior-posterior and lateral cement plume diameters and pullout strength in cadaveric vertebra and foam blocks, respectively. Within instrumented vertebra, variables such as the width of the vertebral body and screw insertion were found to significantly correlate with enhanced fixation. CT analysis of the instrumented vertebra demonstrated that a centrally distributed pattern of fenestrations was found to result in a cement plume with consistently predictable distribution within the vertebral body, without evidence of leak. CONCLUSION: Cementation of fenestrated pedicle screws increases overall pullout forces; however, there is an unclear relationship between the geometric properties of the cement plume and the overall strength of the screw-bone interface. This study demonstrates that the plume diameter, vertebral body width, and angle of screw insertion are correlated with enhanced pullout strength. Furthermore, varying the fenestration design of injectable screws resulted in a set of predictable plume patterns, which may be associated with fewer complications. Further investigation is required to clarify the optimal geometric and biomechanical properties of injectable pedicle screws and their role in establishing the cement-bone interface. CLINICAL RELEVANCE: This study is relevant to currently practicing spinal surgeons and biomechanical engineers.

Outcomes of direct lateral interbody fusion (DLIF) in an Australian cohort.

BACKGROUND: Direct lateral interbody fusion (DLIF) mitigates many of the vascular complications and bony resections associated with other interbody fusion techniques. However, there are concerns regarding postoperative neural complications and that indirect decompression of the foramen has not been consistently demonstrated. This study prospectively assessed the clinical and radiological outcomes and the complication rates of the DLIF approach. METHODS: A prospective review was conducted of the first 50 consecutive DLIF cases of a single neurosurgeon between 2010 and 2014. Clinical outcomes were assessed using Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ) surveys. Radiological outcomes, including spondylolisthesis, disc height, local disc angle, lumbar lordosis and foraminal height and width, were measured using Surgimap Spine software at the preoperative, 6 weeks, 6 months, and 12 months postoperative follow-up. Complication rates were also reported. RESULTS: A total of 50 patients (84 levels) were treated with DLIF. The mean patient age was 68.2±9.8 years and 62.0% were female. At latest follow-up, mean VAS pain score improved from 7.7±1.5 to 1.9±0.9 (P<0.0001), mean ODI improved from 42.1±14.5 to 16.9±6.7 (P<0.0001) and mean RMDQ score improved from 12.1±5.2 to 6.2±4.7 (P<0.0001). Mean spondylolisthesis reduced from 7.5%±6.5% to 1.3%±1.1% at 6 weeks (P<0.0001), 0.95%±0.74% at 6 months (P<0.0001) and recurred to 1.9%±1.7% at 12 months postoperatively (P=0.0006). Mean anterior disc height improved from 7.3±3.2 to 11.6±2.5 mm at 6 weeks (P<0.0001), 12.2±3.3 mm at 6 months (P<0.0001) and 9.8±2.1 mm at 12 months (P=0.0032) postoperatively. Mean posterior disc height improved from 4.4±2.0 to 6.8±2.1 mm at 6 weeks (P<0.0001), 6.6±2.5 mm at 6 months (P=0.0003), and 5.9±1.4 mm at 12 months (P=0.0039) postoperatively. Mean local disc angle improved from 7.0°±3.7° to 9.2°±3.3° at 6 weeks (P=0.0072), 10.4°±3.9° at 6 months (P=0.0013) and 8.2°±2.9° at 12 months (P=0.2487) postoperatively. No significant postoperative changes in lumbar lordosis were observed. Mean foraminal height improved from 18.3±3.5 to 21.5±3.9 mm at 6 weeks (P=0.0004), 20.6±3.4 mm at 6 months (P=0.0266), and 18.7±1.9 mm at 12 months (P=0.8021) postoperatively. Mean foraminal width improved from 7.9±2.0 to 10.2±2.8 mm at 6 weeks (P=0.0001), 9.4±2.6 mm at 6 months (P=0.0219) and 8.3±1.6 mm at 12 months (P=0.5734) postoperatively. Fusion rate at 6 and 12 months was 62.2% and 89.2%, respectively. A total of 6 patients (12%) had postoperative complications. Three patients (6%) had pain-related psoas muscle weakness and 3 patients (6%) had sensory neural complications that had resolved entirely by 8 and 16 weeks postoperatively, respectively. CONCLUSIONS: The study provides encouraging short and medium-term clinical and radiological results for DLIF. In this patient series, there was a low complication rate with no permanent neural injury reported.

Clinical presentation and surgical outcomes of an intramedullary C2 spinal cord cavernoma: a case report and review of the relevant literature.

BACKGROUND: The spinal cord intramedullary cavernoma (SCIC) is a rare form of hemangioma that typically behaves as a space-occupying lesion resulting in neurological symptoms, including bladder and bowel dysfunction. To date, there have been few reports characterizing the clinical presentations and surgical outcomes of cavernomas at the C2 spinal level or the potential for resolution of bladder and bowel symptoms postoperatively. This case details the clinical course of a patient with a C2 cavernoma with an atypical neurological presentation and rapid improvement in both bladder and bowel function postoperatively. This case reviews the relevant literature and describes the patient's clinical presentation, radiological and pathological findings and post-surgical progress. METHODS: A 56-year-old male presented with sensory changes in his right hand, which rapidly progressed over ensuing weeks to bilateral sensory changes in the upper and lower limbs, gait imbalance, urinary and faecal incontinence and loss of temperature perception. He subsequently developed significant weakness in the upper limbs. A MRI identified a hematoma in the cervical cord at the C2 level. Given his rapid neurological decline and the social and clinical implications of his bladder and bowel instability, a surgical approach to therapy was adopted. RESULTS: Postoperatively, there was steady improvement in motor and sensory function and a complete return of bladder and bowel function. CONCLUSIONS: Intramedullary spinal cord cavernomas, although rare, can cause significant neurological deficits and morbidity. Surgical excision can provide significant benefits, including restoration of bladder and bowel function.

Lateral lumbar interbody fusion for sagittal balance correction and spinal deformity.

We conducted a systematic review to assess the safety and clinical and radiological outcomes of the recently introduced, direct or extreme lateral lumbar interbody fusion (XLIF) approach for degenerative spinal deformity disorders. Open fusion and instrumentation has traditionally been the mainstay treatment. However, in recent years, there has been an increasing emphasis on minimally invasive fusion and instrumentation techniques, with the aim of minimizing surgical trauma and blood loss and reducing hospitalization. From six electronic databases, 21 eligible studies were included for review. The pooled weighted average mean of preoperative visual analogue scale (VAS) pain scores was 6.8, compared to a postoperative VAS score of 2.9 (p<0.0001). The weighted average preoperative and postoperative coronal segmental Cobb angles were 3.6 and 1.1°, respectively. The weighted average preoperative and postoperative coronal regional Cobb angles were 19.1 and 10.0°, respectively. Regional lumbar lordosis also significantly improved from 35.8 to 43.3°. Sagittal alignment was comparable pre- and postoperatively (34 mm versus 35.1mm). The weighted average operative duration was 125.6 minutes, whilst the mean estimated blood loss was 155 mL. The weighted average hospitalization length was 3.6 days. Whilst the available data is limited, minimally invasive XLIF procedures appear to be a promising alternative for the treatment of scoliosis, with improved functional VAS and Oswestry disability index outcomes and restored coronal deformity. Future comparative studies are warranted to assess the long term benefits and risks of XLIF compared to anterior and posterior procedures.