Reducing the radiation exposure from CT scanning in children with shunts: a nationwide survey and a departmental CT protocol.

INTRODUCTION: Low dose ionising radiation such as from CT scans carries a low but cumulative risk of cancer and children are particularly sensitive. Children with VP Shunts often undergo multiple CT scans. We developed a CT protocol with reduced radiation for paediatric patients with shunts and compared it with the current practice in the other neurosurgical units in the UK and ROI by conducting a nationwide survey. METHODS: An email questionnaire was send to the superintendent radiographer in every Neurosurgical unit in the UK and the ROI. RESULTS: The response rate was 70%. Only 5 (19%) of the responding units used a dedicated CT shunt protocol with reduced radiation. Radiation was reduced by lowering the tube current. In comparison, our protocol uses a combination of less tube current and fewer slices. This reduced the radiation exposure of a CT head significantly with sufficient image quality to make a diagnosis. CONCLUSION: Radiation from CT for paediatric shunt patients scans can and should be reduced. This can be achieved by using reduced radiation protocols. A national paediatric CT shunt protocol could lead to significant reduction in effective radiation dose.

Real-time symptom reporting during elective intracranial pressure monitoring using an interactive handset.

BACKGROUND: Determining whether symptoms are related to abnormal intracranial pressure (ICP) may prove challenging in some cases. We evaluated the utility of an in-house designed interactive handset which allows the real-time recording of symptoms during ICP monitoring. METHODS: Adult patients undergoing elective continuous ICP monitoring using the device to investigate symptoms between November 2013 and June 2015 were included in this retrospective observational cohort study. The device allowed the following symptoms to be recorded: mild, moderate and severe headache, visual disturbance and nausea. The corresponding ICP and ICP trend were also recorded. RESULTS: Twenty seven patients underwent 29 episodes of ICP monitoring, reporting 383 symptoms (mild 18%, moderate 39%, severe 20% headaches, visual disturbance 15% and nausea 8%) over a median period of 48 hours (IQR 12). The median number of symptoms reported during each episode was 11 (IQR 11). The mean ICP associated with a symptom episode was 7mmHg (Range -10 to 45). Mild, moderate and severe headache complaints were associated with mean ICPs of 5 (-9 to 26), 6 (-10 to 35) and 14 (-10 to 45) mmHg respectively. The majority of complaints (68%) were reported during instances of normal ICP. Following monitoring, non-operative management was employed on 21 occasions (72%) including valve pressure adjustment on two occasions whilst surgical intervention was required on eight occasions (28%; two surgeries for under-drainage and six for over-drainage). CONCLUSIONS: The device allows the clinician to accurately match a patient's symptoms with ICP to facilitate management decisions. In most instances, symptoms did not closely correlate with an abnormal ICP. By automating and standardising the collection of symptom data, this device may serve as an efficient adjunct when investigating patients with complex hydrocephalus.

Gravity-assisted valve (GAV) systems to prevent low-pressure headaches in patients with lumboperitoneal shunts.

OBJECTIVES: Low-pressure symptoms after lumboperitoneal (LP) shunting for idiopathic intracranial hypertension (IIH) remain a significant problem. Gravity-assisted valves (GAV) operate at a higher pressure in a vertical position and therefore aim to reduce postural over-drainage. We audited patients with GAV valves inserted in their shunt system to assess their efficacy in reducing low-pressure symptoms and ascertain whether the additional cost of such device can be justified. METHOD: Using a standard proforma, we reviewed patient medical notes and recorded indications and post-operative outcomes in symptom control. RESULTS: In total, 24 patients had the GAV system inserted, 12 had low-pressure symptoms after LP and had LP shunts inserted with GAV valves and 11 in developed low-pressure symptoms after insertion of plane LP shunts and had GAV valves added as secondary procedures. One patient was excluded from the study because the indication for the GAV system was secondary to the presence of low lying cerebellar tonsils (secondary Chiari) rather than headache in a patient with IIH who had undergone previous LP shunt insertion. The GAV system was introduced to prevent further tonsillar decent.Out of 23 patients, 17 patients who had the system inserted to prevent or improve low-pressure symptoms reported improvement in their symptoms. CONCLUSIONS: GAV inserted into LP shunts were effective in reducing low-pressure headaches induced by changes in posture whilst still sufficiently lowering ICP to ameliorate high-pressure symptoms.

CSF hydrothorax: An unusual cause of pleural effusion.

A 20-year-old male with hydrocephalus managed with a ventriculoperitoneal shunt (VP) was diagnosed with a cerebrospinal fluid (CSF) pleural effusion. Imaging studies revealed an intrathoracic course of a disconnected VP shunt. Physicians should consider CSF effusion in their differential diagnosis in patients with a VP shunt and an unexplained pleural effusion.

Counting the cost of negligence in neurosurgery: Lessons to be learned from 10 years of claims in the NHS.

INTRODUCTION: Despite substantial progress in modernising neurosurgery, the specialty still tops the list of medico-legal claims. Understanding the factors associated with negligence claims is vital if we are to identify areas of underperformance and subsequently improve patient safety. Here we provide data on trends in neurosurgical negligence claims over a 10-year period in England. METHODS: We used data provided by the National Health Service Litigation Authority to analyse negligence claims related to neurosurgery from the financial years 2002/2003 to 2011/2012. Using the abstracts provided, we extracted information pertaining to the underlying pathology, injury severity, nature of misadventure and claim value. RESULTS: Over the 10-year period, the annual number of claims increased significantly. In total, there were 794 negligence claims (range 50-117/year); of the 613 closed cases, 405 (66.1%) were successful. The total cost related to claims during the 10 years was £65.7 million, with a mean claim per successful case of £0.16 million (total damages, defence and claimant costs of £45.1, £6.36 and £14.3 million, respectively). Claims related to emergency cases were more costly compared to those of elective cases (£209,327 vs. £112,627; P=0.002). Spinal cases represented the most frequently litigated procedures (350; 44.1% of total), inadequate surgical performance the most common misadventure (231; 29.1%) and fatality the commonest injury implicated in claims (102; 12.8%). Negligence claims related to wrong-site surgery and cauda equina syndrome were frequently successful (26/26; 100% and 14/16; 87.5% of closed cases, respectively). CONCLUSION: In England, the number of neurosurgical negligence claims is increasing, the financial cost substantial, and the burden significant. Lessons to be learned from the study are of paramount importance to reduce future cases of negligence and improve patient care.

Routine but risky: a multi-centre analysis of the outcomes of cranioplasty in the Northeast of England.

BACKGROUND: Cranioplasty is undertaken as a routine secondary operation following craniectomy. At a time when decompressive craniectomy is being evaluated by several large trials, we aimed to evaluate the morbidity associated with cranioplasty and investigate its potential effect on outcome. METHODS: The outcomes of 166 patients undergoing cranioplasty at two centres in the United Kingdom between June 2006 and September 2011 were retrospectively analysed. Outcome measures included mortality, morbidity and functional outcome determined by the modified Rankin score (mRS) at last follow-up. A logistic regression analysis was performed to model and predict determinants related to neurological outcome following cranioplasty. RESULTS: Sixty-seven out of 166 patients (40.4 %) experienced at least one complication during a median follow-up time of 15 months (inter-quartile range 5-38 months). Thirty six patients (21.7 %) developed infection requiring antibiotics, with 27 (16.3 %) requiring removal of the cranioplasty. Nine of 25 patients (36 %) with bi-frontal defects developed an infection whereas 21 of the 153 patients (16.4 %) with a defect other than bi-frontal developed an infection (Chi square p = 0.009). Further surgery in the two groups was required in 16.4 % and 11.7, % respectively. Pseudomeningocoele (9 %), seizures (8.4 %) and poor cosmesis (7.2 %) were also commonly observed. Logistic regression analysis identified initial operation (p < 0.03), mRS at the time of cranioplasty (p < 0.0001) and complications (p < 0.04) as being predictive of neurological outcome at last follow-up. Age at the time of cranioplasty and the timing of cranioplasty were not predictive of last mRS score at follow-up. CONCLUSIONS: Cranioplasty harbours significant morbidity, a risk that appears to be higher with a bifrontal defect. The complications experienced influence subsequent functional outcome. The timing of cranioplasty, early or late, after the initial operation does not impact on the ultimate outcome. These findings should be considered when making decisions relating to craniectomy and cranioplasty.

Prospective analysis of the trial period for spinal cord stimulation treatment for chronic pain.

OBJECTIVE: To determine patient preferences regarding the duration of trial period. MATERIALS AND METHODS: Forty patients were given a trial of spinal cord stimulation. They were questioned daily if they would like to proceed to a permanent implant. Three consecutive affirmative answers implied a successful trial; three negative replies implied a failed trial. Patients rated daily the pain from the surgery, original pain, satisfaction with the stimulator, and the duration of the use of the stimulator. RESULTS: The trial duration varied from 3 to 15 days. Patients with a failed trial took longer to make a decision and also experienced prolonged surgical pain. The majority of patients with a successful trial experienced more than 50% pain reduction. The rate of infection was 7.5%, which has reduced to 2.8% after changing the dressing protocol. CONCLUSIONS: In this study, all patients could make a decision in 15 days, with successful trials requiring a shorter duration. The conversion rate was similar to rates in literature despite patients making a decision without physician input.

Recurrence of fourth ventricular choroid plexus papilloma with late occurrence of a spinal drop metastasis.

Choroid plexus papillomas are rare tumours, which occasionally spread both intracranially and down the spinal canal. Spinal metastasis has been reported infrequently and only once many years since the initial diagnosis. This is the first reported case of late recurrence, metastasis and transformation of a benign to an atypical lesion.

Flow dynamics in lumboperitoneal shunts and their implications in vivo.

OBJECT: Lumboperitoneal shunting is the standard treatment for pseudotumour cerebri or idiopathic intracranial hypertension. Complications are common, particularly the problem of overdrainage leading to low pressure symptoms. The authors designed a simple experiment using catheters of different lengths that drained at different pressure heads and with different vertical drops to study the flow characteristics in these shunts and determine the optimal catheter placement and length that would reduce the occurrence of low pressure headaches. METHODS: The flow rates through catheters of 3 different lengths (60, 83, and 100 cm) with the same internal radius, at 3 different pressure heads (15, 25, and 35 cm H2O to simulate 3 different placements in the lumbar theca), and 3 different vertical drops (10, 20, and 30 cm to simulate the possible effect of siphoning) were measured and the results analyzed. RESULTS: Application of Poiseuille's law and Bernoulli's principle to the experimental design shows that the volume of flow is directly proportional to the sum of the pressure head and the vertical drop and inversely proportional to the length of the catheter. The flow rate through the standard catheter lengths over the course of 24 hours can be abnormally high. An attempt to predict the optimal catheter length was made. CONCLUSIONS: Although the catheter position in the theca and abdomen cannot be altered significantly and the internal radius of the tube cannot be reduced further without increasing the risk of blockage, the length of the tube can be increased to combat overdrainage. The authors suggest that currently available catheters are too short.