Surgical management of acute subdural haematomas: current practice patterns in the United Kingdom and the Republic of Ireland.

INTRODUCTION: Uncertainty remains as to the role of decompressive craniectomy (DC) for primary evacuation of acute subdural haematomas (ASDH). In 2011, a collaborative group was formed in the UK with the aim of answering the following question: "What is the clinical- and cost-effectiveness of decompressive craniectomy, in comparison with craniotomy for adult patients undergoing primary evacuation of an ASDH?" The proposed RESCUE-ASDH trial (Randomised Evaluation of Surgery with Craniectomy for patients Undergoing Evacuation of Acute Subdural Haematoma) is a multicentre, pragmatic, parallel group randomised trial of DC versus craniotomy for adult head-injured patients with an ASDH. In this study, we used an online questionnaire to assess the current practice patterns in the management of ASDH in the UK and the Republic of Ireland, and to gauge neurosurgical opinion regarding the proposed RESCUE-ASDH trial. MATERIALS AND METHODS: A questionnaire survey of full members of the Society of British Neurological Surgeons and members of the British Neurosurgical Trainees Association was undertaken between the beginning of May and the end of July 2012. RESULTS: The online questionnaire was answered by 95 neurosurgeons representing 31 of the 32 neurosurgical units managing adult head-injured patients in the UK and the Republic of Ireland. Forty-five percent of the respondents use primary DC in at least 25% of patients with ASDH. In addition, of the 22 neurosurgical units with at least two Consultant respondents, only three units (14%) showed intradepartmental agreement regarding the proportion of their patients receiving a primary DC for ASDH. CONCLUSION: The survey results demonstrate that there is significant uncertainty as to the optimal surgical technique for primary evacuation of ASDH. The fact that the majority of the respondents are willing to become collaborators in the planned RESCUE-ASDH trial highlights the relevance of this important subject to the neurosurgical community in the UK and Ireland.

(1)H MR Spectroscopy in Gliomatosis: Is there a Sensitivity Issue?

Objective. (1)H MR spectroscopy (MRS) is widely performed for assessment of brain tumours and is considered a highly sensitive technique capable of differentiating benign from malignant conditions and tumour grading. Method. We present a case of a 69 year old woman who was suspected to have gliomatosis on MRI. Results. MRS performed using single voxel and chemical shift/multivoxel techniques was within normal limits. A repeat scan 6 months later showed progressive disease, and biopsy was performed that proved the diagnosis of glioblastoma. Conclusion. Normal MRS in a patient with suspicion of gliomatosis on MRI should not reassure clinicians into assuming a benign aetiology or a good prognosis in short term.

Photodynamic diagnosis (PDD) for upper urinary tract transitional cell carcinoma (UT-TCC): evolution of a new technique.

INTRODUCTION: Transitional cell carcinoma of renal pelvis and ureter account was traditionally treated with nephroureterectomy. With the advent of rigid and flexible ureteroscopes endoscopic access to the ureter and renal pelvis for diagnosis and treatment has become a reality. We did fluorescence ureteroscopy using oral 5-ALA to diagnose upper tract urothelial tumours for four patients. Here we describe this technique and assess its feasibility to diagnose ureteric and renal pelvicalyceal tumours. MATERIALS AND METHODS: A prospective pilot study was performed to assess the feasibility of PDD using oral 5-amino levulinic acid (ALA) for upper urinary tract tumours. RESULTS: Four patients underwent PDD guided flexible ureteroscopy of the upper urinary tract. Obvious exophytic tumour seen on white light was also seen as red fluorescence on blue light. All areas with red fluorescence were biopsied (including additional areas not seen on white light) and were confirmed to be transitional cell carcinoma. CONCLUSION: Photodynamic diagnosis using oral 5-ALA and subsequent treatment of upper tract urothelial tumours is safe and feasible with additional advantages of detecting lesions not visualised on conventional white light endoscopy.

Robotic neurological surgery applications: accuracy and consistency or pure fantasy?

INTRODUCTION: Minimally invasive surgery was born out of recent advances in neuroimaging and stereotaxy, and the scale of future neurosurgical procedures will soon be so small that it will not be possible for the unassisted surgeons. Hence, neurosurgical robotics is a natural evolution in this field. The aim of this study was to evaluate the performance of a new robotic system in a wide range of neurosurgical applications. METHODS: Patients undergoing image-guided surgical procedures were recruited to participate in this prospective ethically approved study from 2005. The PathFinder (Prosurgics, UK) is a neurosurgical robotic system with 6 degrees of freedom. It uses a fiducial system that is automatically detectable by the planning software and a camera system embedded in the robot's head. The registration procedure was performed automatically by photographing the fiducials from different angles. The robot then aligns its end-effector and tool holder along the specified path for the surgeon to pass the probe to the target. We recruited 37 consecutive patients to test the application accuracy and consistency of the system using three different fiducial fixation mechanisms: a double adhesive fixed to the skin, an ECG lead dot fixed to the skin, and a registration plate fixed to the skull. RESULTS: Out of 37 consecutive patients, 17 were males and 20 were females, with a mean age of 46.6 years. The procedures were: transsphenoidal in 8, malignant tumour biopsies in 3 and resections in 5, benign tumour excisions in 6 and functional procedures in 15 [6 bilateral deep-brain stimulations (DBSs) of the subthalamic nucleus for Parkinson's disease, 3 bilateral anterior cingulotomies for depression, 3 bilateral DBSs of the ventral intermediate nucleus of the thalamus for tremor and 3 depth electrodes during epilepsy surgery]. We tested a total of 140 targets with an average of 3-4 targets per patient. The mean application accuracy was less than 1 mm and the application accuracy was consistent in all targets in the same patient. CONCLUSIONS: This robotic system was very accurate and consistent in practice as long as the robot had achieved acceptable registration.

Intracranial enterogenous cyst extending into both supratentorial and infratentorial compartments: case report and review of the literature.

Intracranial enterogenous cysts are rare. There have been only two cases reported of such cysts that extended into both the infratentorial and supratentorial compartments. We add a third case and review the literature to assess their pathogenesis, clinical features, and management.

Validation of the PathFinder neurosurgical robot using a phantom.

BACKGROUND: Minimally invasive surgery was born out of recent advances in neuro-imaging and stereotactic technology. As a result, the scale of neurosurgical procedures will soon be so small that it will not be within the ability of the most gifted and skilled neurosurgeons of today. Hence, neurosurgical robotics is the natural evolution in this field. The aim of this study was to evaluate the performance of a new robotic system in a neurosurgical phantom, comparing it to standard frame-based and frameless technology of today. METHODS: In total, 19 different targets were approached by two standard stereotactic frames, the Stealth Station frameless system and the robot. The CRW and the ZD stereotactic frames were used. The frameless system was the Stealth Station image guidance system. The phantom used was a replica of the human skull fitted with 10 surface and nine deep targets. RESULTS: The robotic system outperformed both frame-based and frameless systems in all experiments in this study. The application accuracies were: robot, 0.5 mm; stereotactic frames, 0.98 mm; and frameless system, 1.96 mm. CONCLUSIONS: The robotic system was as accurate as the stereotactic frame, but without technical restrictions and cumbersome manual adjustments. Furthermore, the robotic system had near-absolute geometric accuracy, was reliable to perform the same procedure over and over without tiresomeness, variation or boredom, and would be impervious to biohazards and hostile environments.

Robotic application in epilepsy surgery.

BACKGROUND: Epilepsy surgery is cost-effective and dependent on patient selection, localization and meticulous technique. We report the use of a new robotic system in this surgery for the first time. METHODS: The brain is imaged for both image guidance and robotic application. The robot uses CT-visible reflective fiducials. Registration is performed by image-guided surgery (IGS) system and the robot. The robot is used to insert depth electrodes for intra-operative epileptic focus localization and to localize the temporal horn. RESULTS: This technique was used in three patients; the catheter tip was found in the temporal horn in all cases and saved considerable operating time compared to previous experience. CONCLUSION: It is therefore feasible to use the robot to localize the temporal horn and place depth electrodes during epilepsy surgery with greater precision and consistency and potential time savings.

Frameless stereotactic neurosurgery: two steps towards the Holy Grail of surgical navigation.

The holy grail of surgical navigation is to provide precise continuous feedback during surgery about the target and its surrounding structures. The first step was the ability of hardware and software technology to allow patient-to-image registration using a multi-potentiometer position-sensing articulated arm system. We used such a system (OAS; Radionics, Burlington, Mass., USA) in 169 consecutive patients with common intracranial lesions. We achieved a mean application accuracy of 2.5 mm, which was sufficiently reliable for most neurosurgical procedures. However, to get the feedback information, the surgeon has to look away from the operative field to the workstation monitor. As psychological studies of manual workers including surgeons indicated that performance is better when the worker is looking in a downward gaze at his hands, the natural progression was to project feedback information between the eyes and the hands. Therefore, the second step was to link tracking technology to the surgical microscope with head-up display. We used such a system (SMN-Zeiss, Germany) in 65 consecutive patients with a mean application accuracy of 1.4 mm. This was again sufficiently reliable for neuronavigation. The head-up display provided continuous feedback to the surgeon about the target, risk zones and areas of interest without the need to interrupt the procedure to get such information. Furthermore, the use of the focal length of SMN with autofocus to perform the registration improved the application accuracy of this technology. The ability of the software to process all MRI sequences (T(1), T(2), MPR and CISS) allowed us to use a variety of image sequences to delineate the lesion more exquisitely.

Audit of neurophysiological recording during movement disorder surgery.

Sixty-two cases of thalamic pallidal and subthalamic surgery in Dundee were audited to assess the influence of physiological localisation on the procedure. Methods included microelectrode recording, evoked potential and stimulation techniques. Although anatomical localisation is improving with modern techniques, the physiological information is still modifying the surgery in 67% of cases.

Staged functional neurosurgery using image fusion: electronic atlas and microelectrode recording at Dundee.

The unforgiving nature of the thalamus, the globus pallidus and the subthalamic nucleus necessitates precise localization of functional targets. This requires the total attention of both the patient and the surgeon. To maximize the concentration of the patient and provide the most accurate localization, we performed staged stereotactic functional procedures. The first stage was performed under general anesthesia to abolish any head movement. We fused CT and MRI images and correlated the fused images with a digitized Talairach brain atlas. We calculated the target coordinates and fixed a modified Bennett Sphere to the skull with the central hole defining the trajectory to the target. The surrounding 12 holes gave parallel trajectories to targets surrounding the anatomical target at 2-mm intervals. The second stage was performed at least a week later under local anesthesia. Microelectrode recording using three simultaneous channels was used to refine the target. Once the microelectrode recordings and macrostimulation confirmed the desired target, a lesion was created or an Activa neurostimulator was inserted. Our early results using this technique in 28 procedures (in 19 patients) indicate a good outcome in 86% and a technical failure in 1 patient.

The use of spring-eye needles in neurosurgery: a survey of neurosurgical theatres in the United Kingdom.

Spring-eye needles were commonly used in neurosurgery as a method of closure of craniotomy incisions because of the perceived, but not proven, advantages of easy handling, fast wound closure and reduced infection rate. However, these needles produce more tissue trauma and are more fragile. We surveyed 33 neurosurgical operating theatres in the UK to find out if spring eyed needles are still in use and, if they are not why not. We had a 91% response. The survey involved 117 British neurosurgeons, of whom spring-eye needles were used by 38 (13%). Both round body and cutting needles were used, but the cutting needles have a higher breakage rate. The use of 'eyed' needles is rare in other surgical specialties but they are still in use in neurosurgical theatres; however, their use has declined because of changes in surgical practice, the increased breakage rate of these needles, and reduction of their availability.

Meningeal chondrosarcomas, a review of 31 patients.

We reviewed the literature to study the clinical features, the management and the outcome of meningeal chondrosarcomas. We included 31 patients in this review: 22 were mesenchymal and nine were non-mesenchymal. The mean age was 27 years and 64% arose from the cranial meninges. The treatment was mainly total surgical excision. Adjuvant therapy was given to 36% of patients. Spinal meningeal chondrosarcomas had a better prognosis (81% 1-year survival and 45% 3-year survival). There were no pathognomonic clinical or radiological features. We concluded that the best management of meningeal chondrosarcomas is total surgical excision whenever possible, followed by combined course of radiotherapy and chemotherapy as soon as possible.