Repair of lateral temporo-sphenoidal encephalocoele via an endoscopic transorbital approach: ex vivo 3D printed simulation followed by in vivo deployment.

BACKGROUND: A temporo-sphenoidal encephalocoele occurs when temporal lobe herniates through a defect in the greater wing of the sphenoid bone into the sphenoid air sinus. The natural history is not well-understood, though presentation in adulthood with CSF rhinorrhoea and/or meningitis is typical. Lateral pneumatisation of the sphenoid sinus and elevated BMI may be contributory. AIMS: We explored the feasibility of a transorbital approach (TOA) for repair, using a combination of 3D modelling and simulation. We then successfully deployed this technique in vivo. METHODS: CT imaging for three patients who had previously undergone transcranial repair of lateral temporo-sphenoidal encephalocoele was used to generate data allowing 3D printed models of the skull base to be produced. The transorbital approach was simulated by performing a lateral orbitotomy followed by drilling of the sphenoid wing to expose the antero-basal middle fossa. 3D object scanning was used to create virtual models of the skull base post-surgery, from which surgical access was quantified in two ways: the area (mm2) of the middle fossa exposed by the TOA and the vertical attack angle. RESULTS: The mean surface area of the cranial access window achieved by simulated TOA was 325mm2. The mean vertical attack angle was 25°. One patient was subsequently treated successfully via TOA with no recurrence of their CSF leak, no orbital morbidity, excellent cosmesis, but resolving V2 numbness (follow-up 7 months). CONCLUSIONS: We have shown that the transorbital approach provides adequate surgical access. In our single case, surgical repair of a lateral temporo-sphenoidal encephalocoele via TOA was feasible, safe, and effective. This approach may offer some advantages compared with transcranial or endonasal approaches.

Exploring the influence of nasal morbidity on quality of life following endoscopic endonasal skull base surgery: a retrospective cohort study of 95 patients.

The endoscopic endonasal approach is more disruptive to normal anatomy (particularly nasal mucosa) than the transseptal submucosal microscopic approach. This may result in greater postoperative nasal morbidity, in turn reducing quality of life. We aimed to assess the severity and time course of nasal morbidity, and its impact on quality of life, following endoscopic endonasal skull base surgery in this retrospective cohort study. We identified 95 patients who underwent endoscopic endonasal skull base surgery for anterior skull base pathologies. Nasal-specific questions from the Sino-Nasal Outcome Test-22 (SNOT-22) and the Anterior Skull Base inventory (ASB-12) were combined with quality-of-life questions. Patient demographics, diagnosis, and operative data were collected from electronic records. Age of the cohort ranged from 14-83 years. Time elapsed since surgery ranged from 3-85 months. 85/95 (89%) felt that nasal morbidity associated with surgery was acceptable, given the underlying reason for, and outcome of surgery; 10/95 (11%) did not. 71/95 (75%) reported no change or improvement in olfaction 3-months following surgery. 24/95 (25%) reported a deterioration in olfaction which was mild in 7%, moderate in 7%, and severe in 11%. Nasal crusting, nasal obstruction, and headache were moderately problematic symptoms but improved significantly by 3-month follow-up. Nasal discharge, nasal pain, and nasal whistling were mildly problematic and improved significantly by 3-months. 62/95 (65%) patients reported 'no change' in day-to-day activities due to the effects on their nose after surgery. 19/95 (20%) had 'mild inconvenience', 8/95 (8%) 'moderate inconvenience' and 6/95 (6%) 'severe inconvenience'. Endoscopic anterior skull base surgery is associated with nasal morbidity. Whilst 35% of patients appreciate a consequent negative impact on day-to-day life, the overwhelming majority feel that nasal morbidity is acceptable, given the wider surgical goals.

Exploring the Impact of Using Patient-Specific 3D Prints during Consent for Skull Base Neurosurgery.

Objectives Informed consent is fundamental to good practice. We hypothesized that a personalized three-dimensional (3D)-printed model of skull base pathology would enhance informed consent and reduce patient anxiety. Design Digital images and communication in medicine (DICOM) files were 3D printed. After a standard pre-surgery consent clinic, patients completed part one of a two-part structured questionnaire. They then interacted with their personalized 3D printed model and completed part two. This explored their perceived involvement in decision-making, anxiety, concerns and also their understanding of lesion location and surgical risks. Descriptive statistics were used to report responses and text classification tools were used to analyze free text responses. Setting and Participants In total,14 patients undergoing elective skull base surgery (with pathologies including skull base meningioma, craniopharyngioma, pituitary adenoma, Rathke cleft cyst, and olfactory neuroblastoma) were prospectively identified at a single unit. Results After 3D model exposure, there was a net trend toward reduced patient-reported anxiety and enhanced patient-perceived involvement in treatment. Thirteen of 14 patients (93%) felt better about their operation and 13/14 patients (93%) thought all patients should have access to personalized 3D models. After exposure, there was a net trend toward improved patient-reported understanding of surgical risks, lesion location, and extent of feeling informed. Thirteen of 14 patients (93%) felt the model helped them understand the surgical anatomy better. Analysis of free text responses to the model found mixed sentiment: 47% positive, 35% neutral, and 18% negative. Conclusion In the context of skull base neurosurgery, personalized 3D-printed models of skull base pathology can inform the surgical consent process, impacting the levels of patient understanding and anxiety.

Emotional visual stimuli and simulated laparoscopic surgical performance: A pilot cohort study.

BACKGROUND: Exposure to stress prior to or during surgery can negatively impact performance. Management of stress is an essential non-technical skill required for safe practice. The effects of exposure to emotional visual stressors on surgical performance are poorly understood. This study aims to develop a model to investigate effects of emotive visual stimuli on simulated laparoscopic performance. METHODS AND MATERIALS: A single-centre cohort study. Thirty novice, simulator-naïve medical students were randomly allocated to view either positive, negative, or neutral emotional images (sourced from validated image registry). Participants focused for 5 s on the image before completing a peg-threading laparoscopic task. Time, instrument distance, speed, acceleration, motion smoothness, and ambidexterity were recorded automatically with instrument tracking software. 8 task cycles were completed; 3 control practices followed by 5 with the stimuli, according to group allocation. RESULTS: The final performance metrics of students (time, distance, speed, and motion smoothness) were not significantly different when comparing positive and neutral stimuli groups to those shown negative stimuli. However, changes were seen in the rate of performance improvements (positive: p = 0.711, p = 0.837, p = 0.297, and p = 0.393) (neutral: p = 0.285, p = 0.918, p = 0.835, and p = 0.396). Participation improved performance metrics overall (p=<0.001, p=<0.001, p = 0.088, p = 0.025, p=<0.001). CONCLUSION: Model systems may be valuable for investigating the impact of stress on surgeon performance. The effect of emotive visual stimuli on surgical performance is complex. This model may aid the further exploration of these relationships and ultimately can provide an environment in which surgeons can develop strategies to mitigate the adverse effect of stressors.

Postoperative Diabetes Insipidus Mimicking Radiological Findings and Symptoms of Intracranial Hypotension: A Case Report.

Endocrine disturbances such as diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone secretion (SIADH) are recognized complications of craniopharyngioma surgery, which occur due to damage to structures that produce or store antidiuretic hormone (ADH). Intracranial hypotension is a clinical syndrome that presents with headache and typical radiological features and can occur due to a leak of cerebral spinal fluid (CSF) in operations that involve the opening of the arachnoid (e.g., craniopharyngioma surgery). We describe a patient presenting with headache, radiological evidence of intracranial hypotension, and chronic DI after craniopharyngioma surgery. This occurred in the absence of evidence of a CSF leak. The headache and radiological findings resolved after the identification and treatment of DI. Intracranial hypotension may have occurred secondary to dehydration in chronic DI. A 48-year-old woman presented with progressive visual field loss due to cystic recurrence of a craniopharyngioma. She underwent redo (second) extended endoscopic transsphenoidal surgery, having previously undergone an uncomplicated debulking procedure two years prior. Her redo operation was uneventful, and her vision improved postoperatively. A lumbar drain was placed preoperatively to protect the skull base repair and was removed after 48 hours. In the initial postoperative period, she developed a clinical (polyuria) and biochemical picture consistent with DI, subsequently reverting to a SIADH, after which fluid and sodium homeostasis appeared to normalize, and she was discharged. Two months after discharge, she re-presented with new headaches eased by lying flat. Magnetic resonance imaging (MRI) brain showed bilateral convexity subdural effusions and diffuse pachymeningeal enhancement, suggesting intracranial hypotension and raising concern for postoperative CSF leak. MRI spine did not show a CSF fistula at the site of the previous lumbar drain. Transsphenoidal examination under anesthesia showed a well-healed skull base repair and no evidence of CSF leak. She concurrently reported polyuria and polydipsia. A formal water deprivation test confirmed central DI. Treatment with desmopressin improved her headache, and a follow-up MRI brain showed resolution of the previous stigmata of intracranial hypotension. This case report reminds physicians and neurosurgeons that systemic disorders (such as dehydration) can cause intracranial hypotension.

The Impact of Novel Nontechnical Stressors (Visual and Auditory) on Simulated Laparoscopic Task Performance Among Surgeons and Students.

Background: Surgical training emphasizes technical competence. Growing evidence indicates that nontechnical skills are also significant in determining performance. Critically, surgeons should be aware how performance is affected by pressure or distraction. We assessed the impact of novel auditory and visual stressors on performance during a simulated laparoscopic task. We hypothesized that the stressors would worsen performance, and that stress-induced diminution in performance would be inversely related to surgical experience. Methods: Twenty participants (10 surgeons and 10 medical students) completed a peg-threading task using a laparoscopic simulator: three times under control conditions, next with a visual distraction overlay (progressive red saturation of the surgical field, timing personalized to the user's index performance), and then with an auditory distraction overlay (operating theater environment noise). Task completion time and instrument tracking metrics (instrument tip distance traveled and instrument smoothness) were measured. Results: Under control conditions, surgeons completed the task significantly faster, with greater economy of movement, and improved instrument smoothness-compared with students. When exposed to distracting stimuli, the groups behaved differently. Surgeons completed the task more slowly, instrument movements became less smooth (significantly so under audio distraction conditions), but total distance traveled by instruments was unchanged. By contrast, student performance was not impaired and, in some ways, improved. Conclusion: The impact of visual and auditory distraction on surgical performance can be modeled in a laparoscopic simulation environment. The effect of distraction varies according to expertise. This environment may be an effective setting within which to learn to mitigate stress-induced diminution in performance.

Development and validation of a hedgehog heparin-binding assay for high-throughput screening.

Sonic hedgehog (Shh) is a morphogenic protein with critical roles in embryogenesis and the development of some cancers. Hence, identifying inhibitors of the Shh pathway is of great therapeutic value. Heparin and HSPGs act as crucial modulators of Shh activity. To identify molecules that antagonize Shh binding to heparin we have developed a solid-phase plate-based assay. The N-terminal domain of Shh (ShhN) protein is first coated in 384-well plates and the direct binding of fluorescein-labeled heparin (flu-heparin) assessed by measuring the fluorescence signal after incubation and wash steps. Binding of ShhN protein to the 384-well plates was confirmed and optimized by a standard ELISA using a monoclonal antibody recognizing folded ShhN. The assay was validated using whole plate minimum and maximum signal wells with a Z' of 0.68-0.75 determined. Herein, we describe the development and validation of a high throughput screen to identify small molecule antagonists of Shh heparin binding. Overall, this method•Results in an optimized and validated assay for hedgehog heparin binding.•Delivers a cost effective high-throughput screen format for hedgehog heparin antagonist screening.

Is a Single-Dose, Single-Agent Perioperative Antibiotic Protocol Adequate for Endoscopic Endonasal Skull Base Surgery? A 10-Year Review of 422 Cases.

Objective Postoperative meningitis is a rare but potentially fatal complication of endoscopic endonasal skull base surgery. Prophylactic antibiotic use varies considerably worldwide. We sought to analyze the safety of a single-agent, single-dose protocol. Design, Setting, and Participants A retrospective review of 422 procedures performed during 404 admission episodes from 2009 to 2019, encompassing sella, parasella, and other anterior skull base pathologies. Main Outcome Measures Primary outcome measure was development of meningitis within 30 days of surgery. Additional information collected: underlying pathological diagnosis, intraoperative cerebrospinal fluid (CSF) leak, postoperative CSF leak, and primary or revision surgery. Results Of 404 admission episodes for endoscopic anterior skull base surgery, 12 cases developed meningitis. Seven had positive CSF cultures and all 12 recovered. For pathology centered on the sella (including pituitary adenoma), the rate of meningitis was 1.1% (3/283). For pathologies demanding an extended approach (including meningioma and craniopharyngioma), the rate of meningitis was 14.5% (9/62). Postoperative CSF leak requiring surgical repair increased the relative risk by 37-fold. There were no cases of meningitis following repair of long-standing CSF fistula or encephalocoele (0/26) and no cases following surgery for sinonasal tumors with skull base involvement (0/33). Conclusion For sella-centered pathologies, a single dose of intravenous co-amoxiclav (or teicoplanin) is associated with rates of meningitis comparable to those reported in the literature. Postoperative meningitis was significantly higher for extended, intradural transphenoidal approaches, especially when postoperative CSF leak occurred. Fastidious efforts to prevent postoperative CSF leak are crucial to minimizing risk of meningitis.

Using Automated Continuous Instrument Tracking to Benchmark Simulated Laparoscopic Performance and Personalize Training.

OBJECTIVE: Laparoscopic simulation is widely used in surgical training. However, the impact of training on performance is difficult to assess. Observation is time-intensive and subjective. SurgTrac laparoscopic box-trainer instrument tracking software provides continuous, automated, real-time, objective performance feedback. We used this data to assess the relationship between task attempts and performance. We assessed whether improvement in performance with repetition could be modeled in learning curves that might be used for benchmarking. DESIGN: Anonymized SurgTrac data for performances undertaken between 10/2016 and 05/2019 were retrospectively extracted. The thread transfer task, a basic instrument handling task, was assessed. Task duration and instrument-based metrics were analyzed; total distance travelled by instrument tips, average speed, average acceleration, and the ratio of movements between the left and right hands. Curve estimation regression was used to assess the relationship between attempt number and metrics for pooled data across the entire cohort of users and amongst individual users with ≥50 attempts. Threshold for significance p = 0.05. SETTING: SurgTrac has generated the largest available database of performances in box trainer simulated tasks with 64,000 activities performed by over 1450 users in 77 countries to date. PARTICIPANTS: Data was derived from the unselected world-wide cohort of SurgTrac users. No participants were excluded. RESULTS: Five hundred seventy-eight users performed 13,027 attempts in the thread transfer task. Across the entire cohort, SurgTrac performance metrics were significantly associated with attempt number. Task duration and total distance decreased with attempt number. This benefit persisted across 100 attempts. Ambidexterity increased with attempt number. Individual candidate performance improved in line with predicted learning curves for better performing candidates. CONCLUSIONS: We analyzed the largest database of simulated laparoscopic task performances. Performance improves with practice. Using learning curves derived from peer-group performances as benchmarks, users may be regularly and objectively assessed to support personalization of training.

Management of spontaneous intracranial hypotension: a series of 31 cases over 15-years with a challenging outlier.

Spontaneous intracranial hypotension (SIH) has been classified as a triad of postural headache, low CSF opening pressure (below 60mmH20) and diffuse pachymeningeal gadolinium enhancement on MRI. SIH is due to a non-iatrogenic defect in the dura somewhere along the neuraxis (usually in the spine). The resultant leak depressurizes the system and undermines the buoyancy-providing quality of CSF. In many cases the site of leak is not identified. Epidural blood patch (EBP) is a well-established treatment of SIH but is not always effective. We retrospectively analysed thirty-one cases of SIH who required at least one EBP. They were managed over a fifteen-year period at a single institution. EBP resulted in a significant improvement in headache for 77% of patients. We report in more detail on a particularly challenging outlier where severe SIH resulted in coma. Serial epidural blood patches, burr hole evacuation of chronic subdural haematomata, and infusion of 0.9% NaCl via an intradural spinal catheter were all required to enable long-term recovery.

Sellar Remodeling after Surgery for Nonfunctioning Pituitary Adenoma: Intercarotid Distance as a Predictor of Recurrence.

Introduction As they grow, pituitary adenoma can remodel the sella turcica and alter anatomical relationships with adjacent structures. The intercarotid distance (ICD) at the level of the sella is a measure of sella width. The purpose of this study was to (1) assess how ICD changes after transsphenoidal surgery and (2) explore whether the extent of ICD change is associated with tumor recurrence. Methods A retrospective analysis of preoperative and postoperative coronal magnetic resonance imaging (MRI) scans was carried out by two independent assessors on patients who underwent transsphenoidal surgery for nonfunctioning pituitary macroadenomas. Preoperative tumor volume and any change in ICD following surgery were recorded and compared between groups. Logistic regression models of recurrence were generated. Results In 36 of 42 patients, ICD fell after surgery (mean = 1.8 mm) and six cases were static. At time of follow-up (mean = 77 months), 25 had not required further intervention and 17 had undergone second surgery or radiosurgery. In patients in whom no further intervention has yet been necessary, the postoperative reduction in ICD was significantly smaller than in those who required repeat intervention (1.1 vs. 2.7 mm respectively, p < 0.01). ICD decrease was weakly correlated with tumor volume ( r = 0.35). ICD decrease was a significant predictor of recurrence (odds ratio [OR] = 3.15; 95% confidence interval [CI]: 1.44-6.87), largely independent of tumor volume. Conclusion For most patients, ICD falls following surgical excision of a nonfunctioning pituitary macroadenoma. A greater reduction in ICD postsurgery appears to predict recurrence. Change in ICD shows promise as a radiographic tool for prognosticating clinical course after surgery.

Enhanced recovery and accelerated discharge after endoscopic transsphenoidal pituitary surgery: safety, patient feedback, and cost implications.

BACKGROUND: Enhanced recovery after surgery (ERAS) is a constant motivation. There is growing evidence that an endoscopic (rather than microscopic) transsphenoidal approach to pituitary tumours can play a role, facilitating faster recovery and a commensurate reduction in length of stay (LOS). Reducing LOS is beneficial to both patients and healthcare systems. We sought to assess the safety, patient feedback, and resource implications of adopting an enhanced recovery and accelerated discharge policy for elective pituitary surgery. METHODS: We retrospectively assessed two consecutive cohorts of patients undergoing elective surgery for pituitary adenoma in a single UK centre between July 2016 and November 2019. The pre-ERAS cohort included 52 sequential patients operated prior to protocol change. The ERAS cohort included 55 sequential patients operated after a protocol change. Patient demographic data, tumour characteristics, intra- and post-operative CSF leak, the rate and cause of readmission (within 30 days), and the mean and median LOS were recorded. Patient feedback was collected from a subset of patients (n = 23) in the ERAS group. RESULTS: The two cohorts were well-matched with respect to their demographic, pathological, and operative characteristics. The rates of readmission within 30 days of discharge were similar between the two groups (8% pre-ERAS cohort, 9% ERAS cohort, p = 0.75). In the pre-ERAS cohort, the mean LOS was 4.5 days and median LOS was 3 days. This compares with significant reduction in LOS for the ERAS group: mean of 1.7 days and median of 1 day (p < 0.05). Thirty-nine of 55 patients in the ERAS group were discharged on post-operative day 1. Patient feedback was very positive in the ERAS group (mean patient satisfaction score of 9.7/10 using a Likert scale). CONCLUSIONS: An enhanced recovery protocol after elective endoscopic pituitary surgery is safe, reduces length of stay, and is associated with high patient satisfaction.

Optically modulated magnetic resonance of erbium implanted silicon.

Er implanted Si is a candidate for quantum and photonic applications; however, several different Er centres are generated, and their symmetry, energy level structure, magnetic and optical properties, and mutual interactions have been poorly understood, which has been a major barrier to the development of these applications. Optically modulated magnetic resonance (OMMR) gives a spectrum of the modulation of an electron paramagnetic resonance (EPR) signal by a tuneable optical field. Our OMMR spectrum of Er implanted Si agrees with three independent measurements, showing that we have made the first measurement of the crystal field splitting of the 4I13/2 manifold of Er implanted Si, and allows us to revise the crystal field splitting of the 4I15/2 manifold. This splitting originates from a photoluminescence (PL) active O coordinated Er centre with orthorhombic C2v symmetry, which neighbours an EPR active O coordinated Er centre with monoclinic C1h symmetry. This pair of centres could form the basis of a controlled NOT (CNOT) gate.

High speed chalcogenide glass electrochemical metallization cells with various active metals.

We fabricated electrochemical metallization cells using a GaLaSO solid electrolyte, an InSnO inactive electrode and active electrodes consisting of various metals (Cu, Ag, Fe, Cu, Mo, Al). Devices with Ag and Cu active metals showed consistent and repeatable resistive switching behaviour, and had a retention of 3 and >43 days, respectively; both had switching speeds of <5 ns. Devices with Cr and Fe active metals displayed incomplete or intermittent resistive switching, and devices with Mo and Al active electrodes displayed no resistive switching ability. Deeper penetration of the active metal into the GaLaSO layer resulted in greater resistive switching ability of the cell. The off-state resistivity was greater for more reactive active metals which may be due to a thicker intermediate layer.

Delayed diffuse cerebellar swelling after resection of medulloblastoma: case report and review of literature.

INTRODUCTION: Delayed diffuse cerebellar swelling is a rare life-threatening complication following medulloblastoma resection. PRESENTATION: We present our experience of managing a 4-year-old who developed diffuse cerebellar swelling with upward herniation 41 days after resection of a large cell anaplastic medulloblastoma. CONCLUSION: Emergency chemotherapy alone was sufficient in promoting regression of swelling and recovery from coma. Reports of similar cases are scant. Chemotherapy may be a critical component of treatment.

Materials Genomics Screens for Adaptive Ion Transport Behavior by Redox-Switchable Microporous Polymer Membranes in Lithium-Sulfur Batteries.

Selective ion transport across membranes is critical to the performance of many electrochemical energy storage devices. While design strategies enabling ion-selective transport are well-established, enhancements in membrane selectivity are made at the expense of ionic conductivity. To design membranes with both high selectivity and high ionic conductivity, there are cues to follow from biological systems, where regulated transport of ions across membranes is achieved by transmembrane proteins. The transport functions of these proteins are sensitive to their environment: physical or chemical perturbations to that environment are met with an adaptive response. Here we advance an analogous strategy for achieving adaptive ion transport in microporous polymer membranes. Along the polymer backbone are placed redox-active switches that are activated in situ, at a prescribed electrochemical potential, by the device's active materials when they enter the membrane's pore. This transformation has little influence on the membrane's ionic conductivity; however, the active-material blocking ability of the membrane is enhanced. We show that when used in lithium-sulfur batteries, these membranes offer markedly improved capacity, efficiency, and cycle-life by sequestering polysulfides in the cathode. The origins and implications of this behavior are explored in detail and point to new opportunities for responsive membranes in battery technology development.

Insinuating electronics in the brain.

There is an expanding interface between electronic engineering and neurosurgery. Rapid advances in microelectronics and materials science, driven largely by consumer demand, are inspiring and accelerating development of a new generation of diagnostic, therapeutic, and prosthetic devices for implantation in the nervous system. This paper reviews some of the basic science underpinning their development and outlines some opportunities and challenges for their use in neurosurgery.

Focused ultrasound as a non-invasive intervention for neurological disease: a review.

Focused ultrasound (FUS) is an incision-less intervention that is a Food and Drug Association (FDA) approved surgical treatment for various pathologies including uterine fibroids and bone metastases. Recent advances in magnetic resonance imaging thermometry and ability to use FUS across the intact calvarium have re-opened interest in the use of FUS in the treatment of neurological diseases. FUS currently has a European CE mark for use in movement disorders. However, it shows potential in the treatment of other neuropathologies including tumours and as a lesional tool in epilepsy. FUS may exert its therapeutic effect through thermal or mechanical fragmentation of intracranial lesions, or by enhancing delivery of pharmaceutical agents across the blood-brain barrier. In this review, we summarise the mechanisms, clinical applications and potential future of FUS for the treatment of neurological disease. We have searched for and described the recently completed and on-going clinical trials investigating FUS for the treatment of neurological disorders. We identified phase one trials investigating utility of FUS in: movement disorders (including essential tremor and Parkinson's disease), chronic pain, obsessive-compulsive disorder and cerebral tumours. Current literature also reports pre-clinical work exploring utility in epilepsy, neurodegenerative conditions (such as Alzheimer's disease) and thrombolysis. Safety and early efficacy data are now emerging, suggesting that transcalvarial FUS is a feasible and safe intervention. Further evidence is required to determine whether FUS is an effective alternative in comparison to current neurosurgical interventions. The cost of requisite hardware is currently a barrier to widespread uptake in UK neurosurgical centres.

The LEAP™ Gesture Interface Device and Take-Home Laparoscopic Simulators: A Study of Construct and Concurrent Validity.

AIM: To assess the potential of the LEAP™ infrared motion tracking device to map laparoscopic instrument movement in a simulated environment. Simulator training is optimized when augmented by objective performance feedback. We explore the potential LEAP has to provide this in a way compatible with affordable take-home simulators. METHOD: LEAP and the previously validated InsTrac visual tracking tool mapped expert and novice performances of a standardized simulated laparoscopic task. Ability to distinguish between the 2 groups (construct validity) and correlation between techniques (concurrent validity) were the primary outcome measures. RESULTS: Forty-three expert and 38 novice performances demonstrated significant differences in LEAP-derived metrics for instrument path distance (P < .001), speed (P = .002), acceleration (P < .001), motion smoothness (P < .001), and distance between the instruments (P = .019). Only instrument path distance demonstrated a correlation between LEAP and InsTrac tracking methods (novices: r = .663, P < .001; experts: r = .536, P < .001). Consistency of LEAP tracking was poor (average % time hands not tracked: 31.9%). CONCLUSION: The LEAP motion device is able to track the movement of hands using instruments in a laparoscopic box simulator. Construct validity is demonstrated by its ability to distinguish novice from expert performances. Only time and instrument path distance demonstrated concurrent validity with an existing tracking method however. A number of limitations to the tracking method used by LEAP have been identified. These need to be addressed before it can be considered an alternative to visual tracking for the delivery of objective performance metrics in take-home laparoscopic simulators.

Interventions for idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) has an estimated incidence of one to three people per 100,000 people per year, and occurs most commonly in obese, young women. IIH is associated with severe morbidity, notably due to a significant threat to sight and severe headache. Several different management options have been proposed. Conservative measures centre on weight loss. Pharmacological therapy includes use of diuretics. Refractory and sight-threatening cases demand surgical intervention, most often in the form of cerebrospinal fluid (CSF) diversion or optic nerve sheath fenestration. Other treatments include venous sinus stenting and bariatric surgery. OBJECTIVES: To assess the effects of any intervention for IIH in any patient group. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2015), EMBASE (January 1980 to July 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 July 2015. SELECTION CRITERIA: We included only randomised controlled trials (RCTs) in which any intervention was compared to placebo, or to another form of treatment, for people with a clinical diagnosis of IIH. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the search results for trials to be included in the review. We resolved any discrepancies by third party decision. MAIN RESULTS: We identified two completed RCTs (enrolling a total of 211 participants and conducted in the UK and US) and two ongoing trials that met the inclusion criteria. Both completed trials compared acetazolamide to placebo, in conjunction with a weight loss intervention in both groups. Attrition bias was a problem in both trials with high loss to follow-up, in one study this loss to follow-up occurred particularly in the acetazolamide arm. One trial was unmasked and we judged it to be at risk of performance and detection bias.In these studies, change in visual acuity was similar in the treatment and control groups as measured by logMAR acuity. In one study people in the acetalomazide group had a similar change in logMAR acuity compared to the placebo group between baseline and 12 months in the right eye (MD 0.04 logMAR, 95% CI -0.08 to 0.16) and left eye (MD 0.03 logMAR, 95% CI -0.09 to 0.15). In the other study people in the acetalomazide group had a similar change in vision over six months compared with people in the placebo group (mean difference in change in letters read was 0.01 (95% CI -1.45 to 1.46). One study reported no cases of visual loss in 21 people treated with acetalomazide compared to 2/20 cases in the placebo group (odds ratio 0.17, 95% CI 0.01, 3.82).The prespecified outcome for this review was reduction in CSF pressure to normal levels which was not reported by the two trials. One trial reported that, in a subsample of 85 participants who agreed to lumbar puncture at 6 months, people in the acetalomazide group on average had a greater reduction in CSF pressure (MD -59.9 mmH(2)O, 95% CI -96.4, -23.4).In one study, people in the acetalozamide group on average experienced a greater reduction in papilloedema as assessed by fundus photographs MD -0.70 (95% CI -1.00 to -0.40) and by clinical grading MD -0.91 (95% CI -1.27 to -0.54) between baseline and six months in the study eye.Headache was recorded as present/absent in one study at 12 months (OR 0.42, 95% CI 0.12,1.41, 41 participants). Both studies reported headache on visual analogue scales (different ones) but results were inconclusive (MD for change in headache score measured on 10-point visual analogue scale at 12 months was 1.0 (-1.80, 3.70, 41 participants) and MD for change in headache score on a 6 point scale measured at 6 months was -0.45 (-3.5,2.6, number of participants unclear).In one study, a similar proportion of people in the acetalomazide group were in remission (however, the trial authors did not state their definition of this term) at 12 months compared to the placebo group. However, the 95% CIs were wide and there is considerable uncertainty as to the effect (OR 1.13 (95% CI 0.32 to 3.90, 41 participants).In one study of 185 participants, people in the acetalomazide group had an increased risk of decreased CO2, diarrhoea, dysgeusia, fatigue, nausea, paresthesia, tinnitus and vomiting compared to people in the placebo group. In general, the estimates of effect were uncertain with wide 95% CIs. Adverse effects were not reported in the other study.One study reported that quality of life was better in acetazolamide-treated patients based on the visual quality of life (VFQ-25) (MD 6.35, 95% CI 2.22 to 10.47) and the physical (MD 3.02, 95% CI 0.34 to 5.70) and mental (MD 3.45, 95% CI 0.35 to 6.55) components of the 36-Item Short Form Health Survey tool at six months. Costs were not reported in either study.We judged the evidence to be low certainty (GRADE) downgrading for imprecision and risk of bias. AUTHORS' CONCLUSIONS: Although the two included RCTs showed modest benefits for acetazolamide for some outcomes, there is insufficient evidence to recommend or reject the efficacy of this intervention, or any other treatments currently available, for treating people with IIH. Further high-quality RCTs are required in order to adequately assess the effect of acetazolamide therapy in people with IIH.