Tim Pigott

Hindbrain decompression for Chiari-syringomyelia complex: an outcome analysis comparing surgical techniques

The natural history of Chiari malformation and our ability to alter it is poorly understood, and reported results of hindbrain decompression show high recurrence rates. We report 11 years of experience of hindbrain decompression, to evaluate long-term outcome related to surgical technique. The results of patients who underwent hindbrain decompression between 1994 and 2005 were retrospectively analysed. We identified 96 patients from operative records and reviewed all clinical records for presenting symptomatology and examination findings. Decompression technique includes traditional decompression, duraplasty and bone—only decompression. Symptoms at the last available follow-up visit were defined by the assessing clinician as resolved, improved, unchanged or worse. There were 35 males and 61 females with a mean age of 33 years (range 6 – 62 years). The mean length of follow-up is 3.6 years with a range of 6 months to 9 years. Postoperative resolution or improvement in symptoms was seen in 75 patients (78%). Drop attacks and headaches were the most likely to respond to hindbrain decompression, showing improvement or resolution in 100 and 92% of cases. Dysaesthetic arm pain and weakness carried the worse prognosis with only 20% having symptom resolution. Sixteen patients had only bony decompression leaving the dura intact. In eight patients (66%) the headaches resolved following bony decompression alone. However the headaches were unchanged in 25% of cases. Dysaesthetic pain and weakness was unchanged in 60%. Restoration of CSF flow dynamics at the foramen magnum by surgical decompression does not consistently result in resolution of symptoms in all patients. Identification of predictors of successful outcome following decompression, coupled with early intervention and appropriate choice of procedure may result in improved outcomes. Although this is a retrospective study it suggests that bone only decompression should be reserved for patients with isolated headache.

Outcome predictors and complications in the management of intradural spinal tumours.

The results of the management of 115 patients with intradural spinal tumours are presented. Data was collected retrospectively from the case notes. Tumours were categorized as intramedullary or extramedullary for statistical analysis. Meningioma, schwannoma and ependymoma accounted for 70% of tumours. Complete macroscopic excision was achieved in 84% of extramedullary and 54% of intramedullary tumours. There were two post-operative deaths, one of which was secondary to methacillin-resistant staphylococcus aureus (MRSA) meningitis. Cerebrospinal fluid leak (10%) and meningitis (7%) were the commonest complications. Ninety-six percent of patients with extramedullary tumours improved or remained unchanged on the Frankel scale. In the intramedullary group, 82% remained unchanged or improved after treatment. Pre-operative functional status was a predictor of good post-operative function for intra- and extramedullary tumours and for intramedullary tumours a good post-operative Frankel score predicted long-term survival.

Temporal trends in head injury outcomes from 2003 to 2009 in England and Wales

Background: Case fatality rates after blunt head injury (HI) did not improve in England and Wales between 1994 and 2003. The United Kingdom National Institute of Clinical Excellence subsequently published HI management guidelines, including the recommendation that patients with severe head injuries (SHIs) should be treated in specialist neuroscience units (NSU). The aim of this study was to investigate trends in case fatality and location of care since the introduction of national HI clinical guidelines. Methods: We conducted a retrospective cohort study using prospectively recorded data from the Trauma and Audit Research Network (TARN) database for patients presenting with blunt trauma between 2003 and 2009. Temporal trends in log odds of death adjusted for case mix were examined for patients with and without HI. Location of care for patients with SHI was also studied by examining trends in the proportion of patients treated in non-NSUs. Results: Since 2003, there was an average 12% reduction in adjusted log odds of death per annum in patients with HI (n=15,173), with a similar but smaller trend in non-HI trauma mortality (n=48,681). During the study period, the proportion of patients with HI treated entirely in non-NSUs decreased from 31% to 19%, (p <0.01). Interpretation: The reduction in odds of death following HI since 2003 is consistent with improved management following the introduction of national HI guidelines and increased treatment of SHI in NSUs.

Conservative management of type II and III odontoid fractures in the elderly at a regional spine centre: A prospective and retrospective cohort study.

Abstract Background. The optimal management of odontoid fractures in the elderly population is unclear and management of this group of patients is complicated by multiple co-morbidities. This study aimed to determine the outcomes after conservative management strategies were applied in this patient group. Methods. We carried out retrospective and prospective analyses of all patients with axial cervical spine injuries, at a single centre. We included patients aged over 60 years with type II and III odontoid fractures. Information was gathered on demographics, ASA grading-associated injuries and complications. The outcome measures were rates and type of union, pain and neurological functions, specifically ambulation. Results. Fifty-seven adult patients with a median age of 78 years (range 60–92 years) were included. There were 42 type II and 15 type III odontoid fractures. Three patients required surgical fixation due to displaced fractures, which could not be reduced with manual traction. Twenty-four (41%) patients were managed with a rigid pinned halo orthosis to obtain adequate reduction and immobilisation. The remaining 30 (53%) were managed in a hard cervical collar. Patients managed with a halo were significantly younger and had more associated injuries than patients managed in a collar (age: t-test = 4.05, p < 0.01, associated injuries: Chi-square = 4.38, p < 0.05). At a mean follow-up of 25 weeks, 87% of type II and 100% of type III fractures had achieved bony union or stable, fibrous non-union. There were no statistical differences in fracture type, follow-up or neurological outcomes between the halo and collar groups. However, overall more patients managed in a collar developed stable fibrous non-union than bony fusion (Fishers exact test, p < 0.05), although this was not significant when analysed by each fracture type individually. A regression model was constructed and identified fracture type as the only independent predictor of time to union, with type III fractures healing faster than type II. Conclusions. High rates of bony union and stable fibrous non-union with a good functional outcome can be achieved in the elderly population sustaining type II or III odontoid fractures, when managed non-surgically. Halo orthosis may not offer any clear advantage over hard collar in this group. Close follow-up is needed for late complications and there must be a willingness to perform surgery if conservative measures fail.

Raised intracranial pressure and hydrocephalus following hindbrain decompression for Chiari I malformation: a case series and review of the literature‡

Object. Chiari-syringomyelia is a heterogeneous condition that may be treated by decompression of the foramen magnum. Raised intracranial pressure (ICP) and/or hydrocephalus is a rare complication of this treatment. We aim to describe the incidence, clinical presentation, radiographic findings, management and outcome of patients developing raised ICP and/or hydrocephalus after hindbrain decompression for Chiari I malformation. Methods. Retrospective analysis of 138 consecutive adult and paediatric patients with Chiari I malformation who underwent foramen magnum decompression. Results. The incidence of post-operative symptomatic raised ICP and/or hydrocephalus in this series was 8.7%. Overall, 9 of 12 patients developing raised ICP or hydrocephalus required a VP shunt, an overall incidence of 6.5%. However, 3 of 12 patients were successfully managed with external ventricular drainage or conservatively. Presentation was with headache or CSF wound leak at a median of 13 days post-operatively. Subdural hygromata were observed in five cases in association with hydrocephalus and urgent drainage to relieve mass effect was required in two cases. At a mean follow up of 36 months, 9 of 12 patients were asymptomatic. Conclusions. There is a risk of requiring a permanent VP shunt associated with decompression for Chiari I even in the absence of ventriculomegaly or signs of raised ICP pre-operatively. Patients presenting with new symptoms or CSF wound leak following FMD mandate investigation to exclude hydrocephalus, raised ICP or subdural hygroma.

The effect of specialist neurosciences care on outcome in adult severe head injury: a cohort study.

BackgroundHead injury is the leading cause of death in trauma. UK national guidelines have recommended that all patients with severe head injury (SHI) should be treated in neuroscience centers. The aim of this study was to investigate the effect of specialist neuroscience care on mortality after SHI. MethodsWe conducted a cohort study using prospectively recorded data from the largest European trauma registry, for adult patients presenting with blunt trauma between 2003 and 2009. Mortality and unadjusted odds of death were compared for patients with SHI treated in neuroscience units (NSU) versus nonspecialist centers. To control for confounding, odds of death associated with non-NSU care were calculated using propensity score-adjusted multivariate logistic regression (explanatory covariates: age, Glasgow Coma Score, Injury Severity Score, treatment center). Sensitivity analyses were performed to study possible bias arising from selective enrollment, from loss to follow-up, and from hidden confounders. Results5411 patients were identified with SHI between 2003 and 2009, with 1485 (27.4%) receiving treatment entirely in non-NSU centers. SHI management in a non-NSU was associated with a 11% increase in crude mortality (P<0.001) and 1.72-fold (95% confidence interval: 1.52-1.96) increase in odds of death. The case mix adjusted odds of death for patients treated in a non-NSU unit with SHI was 1.85 (95% confidence interval: 1.57-2.19). These results were not significantly changed in sensitivity analyses examining selective enrollment or loss to follow-up, and were robust to potential bias from unmeasured confounders. ConclusionsOur data support current national guidelines and suggest that increasing transfer rates to NSUs represents an important strategy in improving outcomes in patients with SHI.BACKGROUND Isoflurane exposure can protect the mammalian brain from subsequent insults such as ischemic stroke. However, this protective preconditioning effect is sexually dimorphic, with isoflurane preconditioning decreasing male while exacerbating female brain damage in a mouse model of cerebral ischemia. Emerging evidence suggests that innate cell sex is an important factor in cell death, with brain cells having sex-specific sensitivities to different insults. We used an in vitro model of isoflurane preconditioning and ischemia to test the hypothesis that isoflurane preconditioning protects male astrocytes while having no effect or even a deleterious effect in female astrocytes after subsequent oxygen and glucose deprivation (OGD). METHODS Sex-segregated astrocyte cultures derived from postnatal day 0 to 1 mice were allowed to reach confluency before being exposed to either 0% (sham preconditioning) or 3% isoflurane preconditioning for 2 hours. Cultures were then returned to normal growth conditions for 22 hours before undergoing 10 hours of OGD. Twenty-four hours after OGD, cell viability was quantified using a lactate dehydrogenase assay. RESULTS Isoflurane preconditioning increased cell survival after OGD compared with sham preconditioning independent of innate cell sex. CONCLUSION More studies are needed to determine how cell type and cell sex may impact on anesthetic preconditioning and subsequent ischemic outcomes in the brain.

The value of MR imaging in differentiating between hard and soft cervical disc disease: a comparison with intraoperative findings.

Abstract The aim of this study is to assess the accuracy of MRI alone in the differentiation of soft cervical disc protrusion from osteophytic compression in cervical disc disease. In a retrospective study, the MRI scans of 41 patients with cervical disc disease, who had previously undergone surgery, were presented to three independent observers, randomly on two different occasions, to identify the accuracy of the diagnosis of the presence of hard or soft disc or both as a cause of compression. The observers (two neurosurgeons and one neuroradiologist) were not involved with the treatment of the cases at any stage and were unaware of the surgical findings. Their observations were compared with those of the surgeon recorded at operation. The intra-observer agreement was poor for diagnosis into three categories as hard or soft disc or both. In distinguishing between the presence or absence of hard disc, there was moderate to good (Kappa = 0.6) intra observer and fair to moderate (Kappa = 0.4) interobserver agreement. The sensitivity of diagnosis of a hard disc was high (87%) but specificity was low (44%), due to the overestimation of the presence of hard disc. There was a significantly higher incidence of hard disc in the elderly age group (76% over the fifth decade, P = 0.0073). It is concluded that MRI alone is not a very efficient diagnostic tool in distinguishing between hard and soft disc in the cervical disc disease.

Applications of the ultrasonic bone cutter in spinal surgery – our preliminary experience

Abstract Objective. To present our experience with the Misonix Ultrasonic Bone scalpel in spinal surgery, highlighting its potential applications and advantages. Methods. Between March and December 2011, a total of 937 spinal cases were performed at a single centre. The Misonix Bone Scalpel (MBS) was used in 62 of these cases. Data were collected prospectively using the Spine Tango registry. Patient demographics, disease type, surgery performed and complications were all recorded along with pre- and post-operative core measures outcome index (COMI). Results. The majority of cases were for spinal degenerative disorders, in particular, revision cases. The bone cutter was also used to achieve laminotomies for access to intradural tumours, corpectomies and a mixture of other pathologies. Of the 62 patients only 1 (1.6%) experienced a blood loss greater than 500 ml, and there was only 1 dural tear (1.6%) as a direct result of the MBS. Four illustrative cases are discussed. Conclusions. The MBS is a useful adjunct in spinal surgery with particular value in revision cases where scar tissue distorts the normal anatomy. There was a low complication rate with a trend to reduced blood loss. This was most apparent to the senior authors during cervical and thoracic corpectomies.

Multiple schwannomas: report of two cases

In this paper authors present two cases of multiple schwannomas without the features of neurofibromatosis (NF). The authors retrospectively reviewed the hospital charts, radiology films, operative notes and pathology slides of these two patients. There was no family history of neurofibromatosis. The two patients had contrast enhanced MRI, which was negative for vestibular schwannomas. Both underwent surgical excision of symptomatic lesions. Histopathology confirmed these lesions as schwannomas. Molecular genetic analysis in case 1 demonstrated two distinct mutations of the NF2 gene in two different schwannomas, with concomitant loss of heterozygosity in both tumours. In contrast peripheral blood lymphocytes did not reveal mutations of NF2. The authors recommend surgery for symptomatic lesions. Asymptomatic tumours can be monitored. Regular follow up is essential as they may develop fresh lesions at any time. The relevant literature is discussed.

High Quality Acute Care for the Severely Injured is not Consistently Available in England, Wales and Northern Ireland: Report of a Survey by the Trauma Committee, The Royal College of Surgeons of England

INTRODUCTION A survey was undertaken to determine the extent to which acute hospitals in England, Wales and Northern Ireland were meeting the acute trauma management standards published in 2000 by The Royal College of Surgeons of England and the British Orthopaedic Association. METHODS A questionnaire comprising 72 questions in 16 categories of management was distributed in July 2003 to all eligible hospitals via the link network of the British Orthopaedic Association. Data were collected over a 3-month period. RESULTS Of 213 eligible hospitals, 161 (76%) responded. In every category of acute care, failure to meet the standards was reported. Only 34 (21%) hospitals met all the 13 indicative standards that were considered pivotal to good trauma care, but all hospitals met at least 7 of these standards. Failures were usually in the organisation of services rather than a lack of resources, with the exception of the inadequate capacity for admission to specialist neurosurgery units. A minority of hospitals reported an inability to provide emergency airway control or insertion of chest tube. The data have not been verified and deficiencies in reporting cannot be excluded. CONCLUSIONS The findings of this survey suggest that high quality care for the severely injured is not available consistently across England, Wales and Northern Ireland, and appear to justify concerns about the ability of the NHS to deal effectively with the current trauma workload and the consequences of a major incident.