Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland.

PURPOSE: Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland. METHODS: A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department. RESULTS: Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments. CONCLUSIONS: There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

A survey of the radiological follow-up of unruptured intracranial aneurysms in the United Kingdom.

OBJECTIVE: Unruptured intracranial aneurysms (UIA) are common. For many the treatment risks outweigh their risk of subarachnoid haemorrhage and patients undergo surveillance imaging. There is little data to inform if and how to monitor UIAs resulting in widely varying practices. This study aimed to determine the current practice of unruptured UIA surveillance in the United Kingdom. METHODS: A questionnaire was designed to address the themes of surveillance protocols for UIA including when surveillance is initiated, how frequently it is performed, and when it is terminated. Additionally, how aneurysm growth is managed and how clinically meaningful growth is defined were explored. The questionnaire was distributed to members of the British Neurovascular Group using probability-based cluster and non-probability purposive sampling methods. RESULTS: Responses were received from 30 of the 30 (100.0%) adult neurosurgical units in the United Kingdom of which 27 (90.0%) routinely perform surveillance for aneurysm growth. Only four units had a unit policy. The mean patient age up to which a unit would initiate follow-up of a low-risk UIA was 65.4 ± 9.0 years. The time points at which imaging is performed varied widely. There was an even split between whether units use a fixed duration of follow-up or an age threshold for terminating surveillance. Forty percent of units will follow-up patients more than 5 years from diagnosis. The magnitude in the change in size that was felt to constitute growth ranged from 1 to 3mm. No units routinely used vessel wall imaging although 27 had access to 3T MRI capable of performing it. CONCLUSIONS: There is marked heterogeneity in surveillance practices between units in the United Kingdom. This study will help units better understand their practice relative to their peers and provide a framework forplanning further research on aneurysm growth.

Middle meningeal artery embolisation for chronic subdural haematomas: the first prospective UK study.

Background/Objectives: MMA embolisation has emerged in recent years as a safe endovascular treatment for chronic subdural haematoma. We report the first UK series of endovascular treatment of chronic subdural haematomas.Design: Prospective case series.Subjects: All adult patients referred with midline shift ≤10 mm and GCS ≥13 were considered. Patients had to be mobile with a standard origin of Middle Meningeal and Ophthalmic arteries. Patients with GCS < 13 or profound weakness (MRC grade ≤ 3) were treated with burr hole drainage and placement of subdural drains.Methods: Patients were recruited over a 14-month period from 25 October 2020 to 25 December 21 through our electronic referral system. Patients' demographics, pre-morbid modified Rankin Score (mRS), symptoms; anticoagulation and co-morbidities were prospectively collected. Suitability for endovascular treatment was discussed with the interventional neuroradiologist and neurosurgeon. SQUID-12 embolic material was used for all MMA embolisations, which was performed under general anaesthetic. Baseline CT/MRI characteristics were collected. Further imaging was obtained at 7, 21, 90 and 180 days. Clinical assessment and mRS was completed at three months.Results: Fifteen patients underwent endovascular embolisation of MMA in the study period. Of these 13 were male, median age was 79 years. Median length of stay was four days. Follow-up CT at three months has demonstrated significant reduction in both midline shift (p = 0.002) and maximum thickness of haematoma (p = 0.001). Nine patients had reached the three months' follow-up period. All of them had complete or near-complete resolution of the CSDH. One patient required surgical rescue at two months post procedure due to progression of CSDH. We report one mortality due to COVID-19.Conclusions: For select patients, MMA embolisation is a safe alternative treatment option for chronic subdural haematoma. As we gain more experience, the procedure could be performed under local anaesthetic.

Treatment of low flow, indirect cavernous sinus dural arteriovenous fistulas with external manual carotid compression - the UK experience.

Introduction: External manual carotid compression (EMCC) is a treatment option for indirect cavernous sinus dural arteriovenous fistulas (CS-DAVF). The exact mechanism of how this works is unclear but compression of the carotid and jugular produces thrombus in the cavernous sinus (CS). Although compression of the superior ophthalmic vein (SOV) has been described as a treatment option this technique is not always amenable. We studied the clinical features, imaging studies, complications and resolution of CS-DAVF in a series seven patients.Materials and methods: Between 2011 and 2017 we treated 7 patients (4 female, 3 male, age range: 60-86 years) with EMCC for an indirect, low-flow CS-DAVF (Barrow B-D). Patients compressed the cervical carotid artery on the side of the CS-DAVF using the contralateral hand for 5-10 seconds 5-10 times per day. Using gradually increasing pressure they compressed the carotid artery and jugular vein until the pulse was no longer palpable.Results: 6 patients had complete resolution of their CS-DAVF within a range of 5-24 months of symptom onset (median 8 months). 5 of our patients had complete resolution of their clinical symptoms at final follow-up. One patient had a failed endovascular procedure, and subsequently underwent surgery to cannulate the SOV for a transvenous endovascular approach to the fistula but in the meantime she had performed EMCC, which is thought to have resolved the fistula. One patient remains under follow-up and is performing EMCC.Conclusion: EMCC is a safe and low risk technique for low-flow indirect CS-DAVF and should be considered as a first line treatment for patients unable to have endovascular treatment. Although compression of the SOV has been described this can often be difficult to perform in the context of periorbital oedema. EMCC should always be performed using the contralateral hand, because this will ensure that the compressing hand falls away should cerebral ischaemia develop.

Observed rupture of unruptured intracranial aneurysms.

Aim: To study the aneurysms where pre and post-rupture imaging was available to determine the impact of rupture on morphology and size of the aneurysm.Methods: A retrospective case series where all cases of ruptured aneurysms over a 5-year period were evaluated and cases identified where pre and post rupture imaging was available. These were then studied in detail.Results: The actual change in the volume of the aneurysm pre and post rupture was quite small and the underlying shape/morphology did not change at all.Conclusion: Post-rupture morphology of aneurysms can be used as representative of pre-rupture morphology. Further larger studies in collaboration with other neurosurgical centres to corroborate this view would be helpful.

Meningioma and mood: exploring the potential for meningioma to affect psychological distress before and after surgical removal.

Background: Much of the research exploring psychological distress with meningioma stem from studies including several brain tumour types (including malignant tumours) meaning that focus on meningioma is limited and that conclusions are based on small samples. Moreover, contradictory findings have been reported regarding the effects of meningioma on mood. Here, the authors present a study exploring pre and post mood scores in meningioma only patients using a sample size larger than any previous research attempt. Method: The Hospital Anxiety and Depression Scale (HADS) was used as an objective measure of mood in a clinical sample of 184 UK patients pre and post meningioma removal surgery. Repeated measures designs were used to assess for significant differences in depression and anxiety scores before and after surgery, chi-squared analyses were used to establish for clinically significant change. Results: The study revealed a significant decrease, and a medium effect size, in mean depression scores after surgery to remove the meningioma (p = .002, g = 0.35). However, no significant effect was found following meningioma removal and anxiety scores (p = .113, g = 0.17). Discussion: No significant effects were determined between mood and meningioma location. A discussion of the findings, and potential implications, is presented.

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.

Percutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia: an alternative technique.

Background: One of the challenges faced by the modern-day NHS is workplace shortages, and experienced radiographers for intra-operative neurosurgical imaging is one such scenario. We describe our method for Percutaneous Retrogasserian Glycerol Rhizotomy (PRGR) using frameless neuronavigation which can be used effectively in such scenarios.Method: Stealth neuronavigation is used for needle placement within the foramen ovale and injection of glycerol, under sedation.Results: In our experience of ten procedures, it is accurate, safe and effective. Good results were obtained on all occasions. It can be repeated as often as necessary using the same Stealth® CT scan and reduces exposure for staff and patients, where repeated injections are required.Conclusion: This simple modification of PRGR technique is effective and safe provided the surgeon has previous experience in undertaking this procedure.

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.

Is tutobone an efficient alternative to other implants used in anterior cervical discectomy and fusion surgeries?

BACKGROUND: The graft site morbidity following iliac crest harvesting is significant. To overcome this, different bone substitutes like coral dowels, solvent dissolved bovine/human bone substitutes, and carbon fiber/titanium cages have been used. This study was undertaken to assess the postoperative radiological fusion rates and symptom relief in patients who had Tutobone used as an interbody spacer compared to autologous bone graft (ABG), cages, surgibone and coral dowels. METHODS: This was a retrospective, observational study. Case notes and post-operative cervical spine radiographs done at two subsequent follow-ups were reviewed. Data were derived from all Anterior Cervical Discectomy and fusion (ACDF) surgeries performed at our centre over a 10-year period for degenerative cervical spine disease. We analysed 530 patients. Exclusion criteria included incomplete notes, complex cervical surgery (both anterior and posterior fixation and vertebrectomies). Patients were divided into 3 groups, patients treated with (1) Autologous bone graft, (2) Tutobone and (3) other implants which include cages, surgibone and coral dowels. RESULTS: An analysis of 530 patients who had ACDF with either ABG (n = 328) or tutobone (n = 95) or other implants (n = 90) is presented. A significantly greater number of patients in whom autologous bone was used had more than one level surgery. The median follow-up times were 3 months and 12 months. Rates of fusion and time to fusion with bone substitutes were inferior to ABG in our series, but there was not much to choose amongst them. CONCLUSION: The use of ABG in ACDF leads to fusion in a shorter duration and greater proportion of patients, when compared to substitutes. Other implants like Tutobone (cheaper alternative), cages, etc can also be used in ACDF procedures with good efficacy with the added advantage of preventing donor site morbidity. There was no association between fusion rates and symptom relief and between use of plating and fusion.

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.