Effectiveness of a Standardized External Ventricular Drain Placement Protocol for Infection Control.

INTRODUCTION: Placement of an external ventricular drain (EVD) is a common procedure routinely completed at bedside by neurosurgical residents. A standardized protocol for placement and maintenance of an EVD is potentially useful. METHODS: This single-institution retrospective review analyzed all patients who underwent placement of an EVD over a 5-year span using a standardized protocol. RESULTS: A total of 428 EVDs in 381 patients were placed as per this protocol. Overall compliance with the practice protocol was 98.7%. Overall, our infection rate was 1.86% (8 external ventricular drain-related infection [ERIs] over 428 EVDs). There was no difference in age for the ERI cases (median 55, range (50.5-60.5), compared with the non-ERI cases (median of 53, range [38-65]) (P = 0.512). Indications for placement of EVD were hemorrhage (51.9%, n = 198), tumor (16.2%, n = 62), trauma (12.8%, n = 49), hydrocephalus (11.5%, n = 44), cerebellar stroke (2.8%, n = 11), infection (3.1%, n = 12), unknown (1.3%, n = 5). Most EVDs (77.6%, n = 296) were placed bedside by second-year residents (median PGY level 2, interquartile range 1-2.75). Computed tomography confirmed placement in the ipsilateral frontal horn in 72% (n = 277) of EVDs. EVD-related complications were noted in 8.3% of EVDs (n = 32, with 8 infections and 24 tract hemorrhages). The median EVD duration was 10 days; duration of EVD had no statistically significant impact on the risk of an ERI (P = 1). Only replacement of an EVD was associated with an increased risk of infection. CONCLUSIONS: Adherence to a standard EVD placement protocol is useful in maintaining a low risk of ERI regardless of the duration of catheter utilization. Replacement of the catheter through the same access hole as the original catheter is associated with an increased risk of ERI.

Accuracy of bolt external ventricular drain insertion by neurosurgeons of different experience.

OBJECTIVE: The accuracy of tunneled external ventricular drain (EVD) placement has been shown to be similar among practitioners of varying experience, but this has not yet been investigated for bolt EVDs. Tunneled and bolt EVDs are distinct techniques, and it is unclear if conclusions regarding accuracy can be inferred from one method to the other. The goal of this study was to determine whether neurosurgical experience influences the accuracy of bolt EVD placement. METHODS: We performed a single-center retrospective analysis of accuracy of bolt EVD placement between 1st December 2018 and 31st May 2020, comparing the accuracy outcomes between three levels of training (junior trainees (JT); mid-grade trainees (MT); senior trainees/fellows (ST)). Accuracy was determined radiologically by two methods: Kakarla grade and by measuring the distance of the catheter tip to its optimal position (DTOP) at the foramen of Monro. RESULTS: Eighty-seven patients underwent insertion of bolt EVDs, of which n = 19 by JT, n = 40 by MT and n = 28 by ST, with a significant difference found between training grades in the median Kakarla grade (p = 0.0055) and in the accuracy of placement as per DTOP (p = 0.0168). CONCLUSIONS: In contrast to previous published results on tunneled EVDs, we demonstrate that the accuracy of bolt EVD placement is dependent on neurosurgical experience. Our results draw awareness to the fact that the bolt EVD technique can represent a challenge for less experienced practitioners and underline the importance of dedicated training to support the safe insertion of bolt ventricular catheters.

Endoscopic versus stereotactic biopsies of intracranial lesions involving the ventricles.

Stereotactic biopsies of ventricular lesions may be less safe and less accurate than biopsies of superficial lesions. Accordingly, endoscopic biopsies have been increasingly used for these lesions. Except for pineal tumors, the literature lacks clear, reliable comparisons of these two methods. All 1581 adults undergoing brain tumor biopsy from 2007 to 2018 were retrospectively assessed. We selected 119 patients with intraventricular or paraventricular lesions considered suitable for both stereotactic and endoscopic biopsies. A total of 85 stereotactic and 38 endoscopic biopsies were performed. Extra procedures, including endoscopic third ventriculostomy and tumor cyst aspiration, were performed simultaneously in 5 stereotactic and 35 endoscopic cases. In 9 cases (5 stereotactic, 4 endoscopic), the biopsies were nondiagnostic (samples were nondiagnostic or the results differed from those obtained from the resected lesions). Three people died: 2 (1 stereotactic, 1 endoscopic) from delayed intraventricular bleeding and 1 (stereotactic) from brain edema. No permanent morbidity occurred. In 6 cases (all stereotactic), additional surgery was required for hydrocephalus within the first month postbiopsy. Rates of nondiagnostic biopsies, serious complications, and additional operations were not significantly different between groups. Mortality was higher after biopsy of lesions involving the ventricles, compared with intracranial lesions in any location (2.4% vs 0.3%, p = 0.016). Rates of nondiagnostic biopsies and complications were similar after endoscopic or stereotactic biopsies. Ventricular area biopsies were associated with higher mortality than biopsies in any brain area.

Discontinuation of External Ventricular Drainage in Patients with Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage - a Scandinavian Multi-institutional Survey.

BACKGROUND: Hydrocephalus requiring external ventricular drainage is common following aneurysmal subarachnoid hemorrhage (aSAH). Timing and strategy for the discontinuation of the external ventricular drain (EVD) are, however, controversial as guidelines are based on limited scientific evidence. A recent similar survey showed that guidelines and recommendations are not being followed. We conducted a questionnaire survey regarding the management of EVD treatment in patients with aSAH and investigated current treatment practice, consensus, and adherence to guidelines within the neurosurgical departments in Scandinavia. METHODS: A questionnaire concerning the management of EVD discontinuation in patients with hydrocephalus following aSAH was distributed to all 14 neurosurgical departments in Scandinavia (Norway, Sweden, and Denmark). Neurosurgeons and neurosurgical trainees at all levels were asked to complete the questionnaire individually. A total of 175 completed questionnaires were received between May 2018 and April 2019, resulting in a response rate of 64 %. RESULTS: Eighty-five percent of respondents reported no knowledge of international guidelines regarding EVD discontinuation in patients with hydrocephalus following aSAH. Within every department, respondents disagreed on whether a common discontinuation strategy was followed or not. Seventy-four percent decided upon the EVD discontinuation strategy mainly determined by patients' clinical condition and drainage volume. Forty-five percent considered Glasgow Coma Score (GCS) the most important clinical variable when assessing the timing of EVD discontinuation. There was general agreement towards the initiation of EVD discontinuation 4-7 days after ictus of aSAH in a stable patient with a drainage volume of < 150 ml/day and intracranial pressure (ICP) < 15 mmHg. CONCLUSION: Awareness of and adherence to international guidelines regarding EVD discontinuation in patients with hydrocephalus following aSAH were limited in Scandinavia. Internal consensus at department level was absent. Initiation of the discontinuation process appeared to be case dependent and mainly influenced by the patients' clinical condition and drainage volume. GCS was the clinical variable considered most important when deciding on the initiation of EVD discontinuation.

Preliminary Results of Emergency Computed Tomography-Guided Ventricular Drain Placement-Precision for the Most Difficult Cases.

BACKGROUND: External ventricular drainage (EVD) catheter placement is one of the most commonly performed neurosurgical procedures. The study's objective was to compare a computed tomography (CT) bolt scan-guided approach for the placement of EVDs with conventional landmark-based insertion. METHODS: In this retrospective case-control study, we analyzed patients undergoing bolt-kit EVD catheter placement, either CT-guided or landmark-based, between 2013 and 2016. The CT bolt scan-guided approach was based on a dose-reduced CT scan after bolt fixation with immediate image reconstruction along the axis of the bolt to evaluate the putative insertion axis. If needed, angulation of the bolt was corrected and the procedure repeated before the catheter was inserted. Primary endpoint was the accuracy of insertion. Secondary endpoints were the overall number of attempts, duration of intervention, complication rates, and cumulative radiation dose. RESULTS: In total, 34 patients were included in the final analysis. In the group undergoing CT-guided placement, the average ventricle width was significantly smaller (P = 0.04) and average midline shift significantly more pronounced (P = 0.01). CT-guided placement resulted in correct positioning of the catheter in the ipsilateral frontal horn in all 100% of the cases compared with landmark-guided insertion (63%; P = 0.01). Application of the CT-guided approach increased the number of total CT scans (3.6 ± 1.9) and the overall radiation dose (3.34 ± 1.61 mSv) compared with the freehand insertion group (1.84 ± 2.0 mSv and 1.55 ± 1.66 mSv). No differences were found for the other secondary outcome parameters. CONCLUSIONS: CT-guided bolt-kit EVD catheter placement is feasible and accurate in the most difficult cases.

Creation of an External Ventricular Drain Registry from a Quality Improvement Project.

BACKGROUND: External ventricular drains (EVDs) are a serious source of morbidity and mortality. Data for interventions proven to reduce risk of infections are lacking. Single-center studies are limited in studying procedures that mitigate infection, but bundled protocols have demonstrated utility. A collaborative EVD registry was designed to facilitate local quality improvement projects to be implemented at any location using standardized data collection instruments through resident collaboration to reduce and study EVD infection and prevention. METHODS: A bundled protocol and comprehensive implementation program were developed as a quality improvement project to reduce ventriculostomy-associated infections. Standardized data collection forms were created for multi-institutional participation in an EVD registry. Retrospective and prospective patient data were documented in an electronic procedural registry, which was designed to capture variation among multiple institutions. RESULTS: Two infections were found in 1924 EVD-days before protocol implementation; no infections were found in 700 EVD-days after protocol implementation. Baseline epidemiology of EVDs was calculated in preparation for comparison. A resident-driven EVD consortium, now with 5 other member institutions, was founded to collect data for an EVD registry fed by individual site quality improvement initiatives. CONCLUSIONS: The ventriculostomy-associated infection rate at the University of Minnesota is low compared with the literature. Rationally bundled protocols have mounting evidence but do not allow for identifying effective individual components. Through the registry described here, others can join the EVD consortium to contribute data to facilitate comparative effectiveness research with minimal investment.

The Incidence of Catheter Tract Hemorrhage and Catheter Placement Accuracy in the CLEAR III Trial.

BACKGROUND: Incidence of catheter tract hemorrhage (CTH) after initial ventriculostomy placement ranges from 10 to 34%. We investigated CTH incidence in the Clot Lysis: Evaluation of Accelerated Resolution of Intraventricular Hemorrhage Phase III trial. METHODS: Prospective observational analysis of 1000 computer tomography (CT) scans from all 500 patients enrolled in the trial. All catheters were evaluated on first CT post-placement and on last CT prior to randomization for placement location and CTH size, location, and severity. Clinical variables were assessed for association with CTH with multivariable logistic regression. RESULTS: Of 563 catheters, CTH was detected in 14 and 21% of patients on first and last CT (median 3.7 and 43.4 h after catheter placement, respectively). All, but one were asymptomatic. Majority of CTH (86%) occurred within 24 h after placement, were located within 1 cm of the skull, and had at least one diameter > 5 mm. Most catheters (71%) terminated in the third or lateral ventricle ipsilateral to insertion site. Factors significantly associated with CTH were pre-admission use of antiplatelet drugs, accuracy of catheter placement, non-operating room catheter placement, Asian race, and intraventricular hemorrhage expansion. CONCLUSIONS: CTH incidence on initial catheter placement and during stabilization was relatively low, despite emergent placement in a high-risk population. Catheter placement accuracy was similar or better than convenience samples from the published literature. Decreasing risk of CTH may be achieved with attention to catheter placement accuracy and placement in the operating room. Antiplatelet agent use was an independent risk factor for CTH.

Contemporary management and surveillance strategy after shunt or endoscopic third ventriculostomy procedures for hydrocephalus.

The management of hydrocephalus can be challenging even in expert hands. Due to acute presentation, recurrence, accompanying complications, the need for urgent diagnosis; a robust management plan is an absolute necessity. We devised a novel time efficient surveillance strategy during emergency, and clinic follow up settings which has never been described in the literature. We searched all articles embracing management/surveillance protocol on pediatric hydrocephalus utilizing the terms "hydrocephalus follow up" or "surveillance protocol after hydrocephalus treatment". The authors present their own strategy based on vast experience in the hydrocephalus management at a single institution. The need for the diagnostic laboratory testing, age and presentation based radiological imaging, significance of neuro-opthalmological exam, and when to consider the emergent exploration have been discussed in detail. Moreover, a definitive triaging strategy has been described with the help of flow chart diagrams for clinicians, and the neurosurgeons in practice. The triage starts from detail history, physical exam, necessary labs, radiological imaging depending on the presentation, and the age of the child. A quick head CT scan helps after shunt surgery while, a FAST sequence MRI scan (fsMRI) is important in post ETV patients. The need for neuro-opthalmological exam, and the shunt series stays vital in asymptomatic patients during regular follow up.

Ventriculostomy-related infections in subarachnoid hemorrhage patients-a retrospective study of incidence, etiology, and antimicrobial therapy.

BACKGROUND: This study was performed to investigate the incidence and etiology of ventriculostomy-related infections (VRIs) in patients with subarachnoid hemorrhage (SAH) and to assess adherence to local clinical guidelines regarding empirical antimicrobial therapy and diagnostic routines. METHODS: A total of 191 consecutive SAH patients treated in the neuro-intensive care unit of Uppsala University Hospital between 2010 and 2013 were included retrospectively. Information regarding cerebrospinal fluid samples, bacterial cultures, ventriculostomy treatment, patient characteristics, and antibiotic treatment were collected from electronic patient records. RESULTS: Eleven patients developed VRI, resulting in an incidence of 5.8% per patient, 5.4% per ventriculostomy catheter, and 4.1 per 1000 catheter days. Coagulase-negative staphylococci caused nine cases of VRI and Klebsiella pneumoniae and Staphylococcus aureus caused one each. Empirical VRI therapy was initiated on 97 occasions in 81 subjects (42.4%). Out of the 11 patients with VRI, four did not receive empirical antibiotic therapy before the positive culture result. The clinical actions performed after analysis of CSF samples were in line with the action suggested by the local guidelines in 307 out of 592 cases (51.9%). CONCLUSIONS: The incidence of VRI in our cohort was comparable to what has previously been reported. Coagulase-negative staphylococci was the most common agent. Our study demonstrates the difficulty in diagnosing VRI in SAH patients. Improved adherence to clinical guidelines could to some extent reduce the use of empirical antibiotic treatment, but better diagnostic methods and routines are needed.

Simplest radiological measurement related to clinical success in endoscopic third ventriculostomy.

OBJECTIVE: Radiologic criteria for a successful endoscopic third ventriculostomy are not clearly defined and there is an ongoing need for determining simplest and strongest radiological criteria for this purpose. This paper aims to determine the easiest radiological parameter related to surgical outcome METHODS: Between January 2012 and December 2015 all patients receiving endoscopic third ventriculostomy with various indications were reviewed and 29 patients whose preoperative and early postoperative 3D-CISS images were available were studied. There were 13 males and 16 females, and there were 11 pediatric cases (mean age: 9.90±5.2; range: 2-18). The mean age of the entire population was 26.58±18.32 (range: 2-68 years). Measurements were performed using the ruler tool of a freely distributed medical imaging software. Simple ruler measurements of ventricular floor depression, lamina terminalis bowing, anterior commissure to tuber cinereum distance, mamillary body to lamina terminalis distance, third ventricular width, frontal horn width and occipital horn width were recorded and compared between successful and failed interventions. RESULTS: Of the ventriculostomies, 22 (75.9%) were considered successful and 7 (24.1%) as failed at the last follow-up visit. Of the measurements performed, only those related to the third ventricle itself were significantly higher in the failed group. There were no association with lateral ventricular measurements. CONCLUSION: Simple ruler measurements of the suggested distances significantly correlate with clinical success. After validating our results with higher number of patients, complex measurements and calculations to determine the link between clinical success and radiological success of ventriculostomy procedures may not be needed.

Characterization of Shape Differences Among ICP Pulses Predicts Outcome of External Ventricular Drainage Weaning Trial.

BACKGROUND: External ventricular drains (EVD) are widely used to manage intracranial pressure (ICP) and hydrocephalus for aneurysmal subarachnoid hemorrhage (aSAH) patients. After days of use, a decision is made to remove the EVD or replace it with a shunt, involving EVD weaning and CT imaging to observe ventricular size and clinical status. This practice may lead to prolonged hospital stay, extra radiation exposure, and neurological insult due to ICP elevation. This study aims to apply a validated morphological clustering analysis of ICP pulse (MOCAIP) algorithm to detect signatures from the pulse waveform to differentiate an intact CSF circulatory system from an abnormal one during EVD weaning. METHODS: We performed a retrospective study with 50 aSAH patients with reported weaning trial admitted to our institution between 03/2013 and 08/2014. By reviewing clinical notes and pre/post-brain imaging results, 32 patients were determined as having passed the weaning trial and 18 patients as having failed the trial. MOCAIP algorithm was applied to ICP signals to form a series of artifact-free dominant pulses. Finally, pulses with similar mean ICP were identified, and amplitude, Euclidean, and geodesic inter-pulse distances were calculated in a 4-h moving window. RESULTS: While the traditional measure of mean ICP failed to differentiate the two groups of patients, the proposed amplitude and morphological inter-pulse measures presented significant differences (p ≤ 0.004). Moreover, receiver operating characteristic (ROC) analyses showed their usability to predict the outcome of the EVD weaning trial (AUC 0.85, p < 0.001). CONCLUSIONS: Patients with an impaired CSF system showed a larger mean and variability of inter-pulse distances, indicating frequent changes on the morphology of pulses. This technique may provide a method to rapidly determine if patients will need placement of a shunt or can simply have the EVD removed.

The Insertion and Management of External Ventricular Drains: An Evidence-Based Consensus Statement : A Statement for Healthcare Professionals from the Neurocritical Care Society.

External ventricular drains (EVDs) are commonly placed to monitor intracranial pressure and manage acute hydrocephalus in patients with a variety of intracranial pathologies. The indications for EVD insertion and their efficacy in the management of these various conditions have been previously addressed in guidelines published by the Brain Trauma Foundation, American Heart Association and combined committees of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons. While it is well recognized that placement of an EVD may be a lifesaving intervention, the benefits can be offset by procedural and catheter-related complications, such as hemorrhage along the catheter tract, catheter malposition, and CSF infection. Despite their widespread use, there are a lack of high-quality data regarding the best methods for placement and management of EVDs to minimize these risks. Existing recommendations are frequently based on observational data from a single center and may be biased to the authors' view. To address the need for a comprehensive set of evidence-based guidelines for EVD management, the Neurocritical Care Society organized a committee of experts in the fields of neurosurgery, neurology, neuroinfectious disease, critical care, pharmacotherapy, and nursing. The Committee generated clinical questions relevant to EVD placement and management. They developed recommendations based on a thorough literature review using the Grading of Recommendations Assessment, Development, and Evaluation system, with emphasis placed not only on the quality of the evidence, but also on the balance of benefits versus risks, patient values and preferences, and resource considerations.

Avoiding Complications in Endoscopic Third Ventriculostomy.

Endoscopic neurosurgical techniques hold the potential for reducing morbidity. But they are also associated with limitations such as the initial learning curve, proximal blind spot, visual obscurity, difficulty in controlling bleeding, disorientation, and loss of stereoscopic image. Although some of the surgical techniques in neuroendoscopy and microsurgery are similar, endoscopy requires additional skills. A thorough understanding of endoscopic techniques and their limitations is required to get maximal benefit. Knowledge of possible complications and techniques to avoid such complications can improve results in endoscopic third ventriculostomy (ETV). The surgeon must be able to manage complications and have a second strategy such as a cerebrospinal fluid shunt if ETV fails. It is better to abandon the procedure if there is disorientation or a higher risk of complications such as bleeding or a thick and opaque floor without any clear visualization of anatomy. Attending live workshops, practice on models and simulators, simpler case selection in the initial learning curve, and hands-on cadaveric workshops can reduce complications. Proper case selection, good surgical technique, and better postoperative care are essential for a good outcome in ETV. Although it is difficult to make a preoperative diagnosis of complex hydrocephalus (combination of communicating and obstructive), improving methods to detect the exact type of hydrocephalus before surgery could increase the success rate of ETV and avoid an unnecessary ETV procedure in such cases.

Development and content validation of performance assessments for endoscopic third ventriculostomy.

PURPOSE: This study aims to develop and establish the content validity of multiple expert rating instruments to assess performance in endoscopic third ventriculostomy (ETV), collectively called the Neuro-Endoscopic Ventriculostomy Assessment Tool (NEVAT). METHODS: The important aspects of ETV were identified through a review of current literature, ETV videos, and discussion with neurosurgeons, fellows, and residents. Three assessment measures were subsequently developed: a procedure-specific checklist (CL), a CL of surgical errors, and a global rating scale (GRS). Neurosurgeons from various countries, all identified as experts in ETV, were then invited to participate in a modified Delphi survey to establish the content validity of these instruments. In each Delphi round, experts rated their agreement including each procedural step, error, and GRS item in the respective instruments on a 5-point Likert scale. RESULTS: Seventeen experts agreed to participate in the study and completed all Delphi rounds. After item generation, a total of 27 procedural CL items, 26 error CL items, and 9 GRS items were posed to Delphi panelists for rating. An additional 17 procedural CL items, 12 error CL items, and 1 GRS item were added by panelists. After three rounds, strong consensus (>80% agreement) was achieved on 35 procedural CL items, 29 error CL items, and 10 GRS items. Moderate consensus (50-80% agreement) was achieved on an additional 7 procedural CL items and 1 error CL item. The final procedural and error checklist contained 42 and 30 items, respectively (divided into setup, exposure, navigation, ventriculostomy, and closure). The final GRS contained 10 items. CONCLUSIONS: We have established the content validity of three ETV assessment measures by iterative consensus of an international expert panel. Each measure provides unique assessment information and thus can be used individually or in combination, depending on the characteristics of the learner and the purpose of the assessment. These instruments must now be evaluated in both the simulated and operative settings, to determine their construct validity and reliability. Ultimately, the measures contained in the NEVAT may prove suitable for formative assessment during ETV training and potentially as summative assessment measures during certification.

External ventricular drain placement in the intensive care unit versus operating room: evaluation of complications and accuracy.

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure performed in both the intensive care unit (ICU) and operating room (OR). The optimal setting for EVD placement in regard to safety and accuracy of placement is poorly defined. METHODS: A retrospective chart review was performed on 150 consecutive patients who underwent EVD placement at a tertiary care center from January of 2013 to February of 2014. Clinical and radiographic data were obtained and used to compare safety and accuracy of placement between EVDs placed in the ICU versus OR. RESULTS: One hundred and thirty eight patients were evaluated. Complications (hemorrhage, infection, non-functional drain) occurred in 21.5% of ICU placements and 6.7% of OR placements (p = 0.028). Grade 1, 2, and 3 placements occurred in 67.7%, 25.8%, and 6.5% of ICU placements, respectively, versus 55.6%, 42.2%, and 2.2% of OR placements (p = 0.258). No patient who received pre-placement antibiotics suffered a ventriculostomy associated infection (VAI). CONCLUSION: Patients who underwent ventriculostomy placement in the ICU differed in important ways (i.e. indication for placement and the administration of pre-procedure prophylactic antibiotics) from patients treated in the OR. However, the available data suggests that complications of hemorrhage, infection, and non-functional drains may be mitigated by ventriculostomy placement in the OR.

Management of hydrocephalus after decompressive craniectomy.

AIM: We set out to investigate the optimal timing for shunt placement in patients with hydrocephalus after decompressive craniectomy (DC). MATERIAL AND METHODS: We studied 63 consecutive patients that underwent DC because of traumatic brain injury, middle cerebral artery infarct or intracerebral hemorrhage. Hydrocephalus was diagnosed in 23/63 patients. The 23 patients were divided into two groups. The first group (A) consisted of 11 patients in whom a ventriculoperitoneal shunt was placed simultaneously or before cranioplasty. In the second group (B) of 12 patients, we performed cranioplasty and a ventriculostomy with monitoring of intracranial pressure was placed simultaneously. After 3 to 5 days, a ventriculoperitoneal shunt was placed with the most appropriate opening pressure. RESULTS: In group A, nine out of the eleven patients experienced complications, mainly hygromas or hematomas that required reoperation. In group B, none of the patients was reoperated. The use of programmable valves allowed for non-invasive revision of the opening pressure when required. CONCLUSION: Cranioplasty and ventriculostomy followed by a second stage placement of a ventriculoperitoneal shunt are associated with fewer complications in the treatment of hydrocephalus after DC.

Transventricular fenestration of the lamina terminalis: the value of a flexible endoscope: technical note.

BACKGROUND: Recently, the authors demonstrated the technical feasibility of a transventricular translaminar terminalis ventriculostomy with a rigid endoscope. A major problem with this technique remains the contusion of the fornix at the foramen of Monro. Here, the authors evaluated alternative approaches and techniques, including the use of a flexible endoscope. MATERIAL AND METHODS: Feasibility of two approaches-anterior and posterior of the coronal suture-was evaluated on magnetic resonance images and in cadaveric brains. Two different trajectories were selected. Lamina terminalis (LT) fenestration was performed with a rigid and a flexible endoscope using two approaches in 10 fixed cadaver brains. RESULTS: Using the posterior approach 2 cm behind the coronal suture with the two endoscopes caused moderate to severe damage to foramen and fornix. Using the standard approach (Kocher point) with the flexible endoscope avoided damage of these structures. After completion of the anatomical investigation, the authors successfully performed a transventricular fenestration of the LT with the flexible endoscope in one clinical case. CONCLUSION: Rigid scopes provide brilliant optics and safe manipulation with the instruments. However, with the rigid scope, a transventricular opening of the LT is only possible with acceptance of structural damage to the foramen of Monro and the fornix. In contrast, opening of the LT via a transventricular route with preservation of the anatomical structures can be achieved with a flexible steerable endoscope even via a standard burr hole. Thus, if a standard third ventriculostomy is not feasible, endoscopic opening of the LT might represent an alternative, particularly with a flexible scope in experienced hands.

Cavitation-based third ventriculostomy using MRI-guided focused ultrasound.

OBJECT: Transcranial focused ultrasound is increasingly being investigated as a minimally invasive treatment for a range of intracranial pathologies. At higher peak rarefaction pressures than those used for thermal ablation, focused ultrasound can initiate inertial cavitation and create holes in the brain by fractionation of the tissue elements. The authors investigated the technical feasibility of using MRI-guided focused ultrasound to perform a third ventriculostomy as a possible noninvasive alternative to endoscopic third ventriculostomy for hydrocephalus. METHODS: A craniectomy was performed in male pigs weighing 13-19 kg to expose the supratentorial brain, leaving the dura mater intact. Seven pigs were treated through the craniectomy, while 2 pigs were treated through ex vivo human skulls placed in the beam path. Registration and targeting was done using T2-weighted MRI sequences. For transcranial treatments a CT scan was used to correct the beam from aberrations due to the skull and maintain a small, high-intensity focus. Sonications were performed at both 650 kHz and 230 kHz at a range of intensities, and the in situ pressures were estimated both from simulations and experimental data to establish a threshold for tissue fractionation in the brain. RESULTS: In craniectomized animals at 650 kHz, a peak pressure ≥ 22.7 MPa for 1 second was needed to reliably create a ventriculostomy. Transcranially at this frequency the ExAblate 4000 was unable to generate the required intensity to fractionate tissue, although cavitation was initiated. At 230 kHz, ventriculostomy was successful through the skull with a peak pressure of 8.8 MPa. CONCLUSIONS: This is the first study to suggest that it is possible to perform a completely noninvasive third ventriculostomy using ultrasound. This may pave the way for future studies and eventually provide an alternative means for the creation of CSF communications in the brain, including perforation of the septum pellucidum or intraventricular membranes.

Percutaneous spinal fixation simulation with virtual reality and haptics.

BACKGROUND: In this study, we evaluated the use of a part-task simulator with 3-dimensional and haptic feedback as a training tool for percutaneous spinal needle placement. OBJECTIVE: To evaluate the learning effectiveness in terms of entry point/target point accuracy of percutaneous spinal needle placement on a high-performance augmented-reality and haptic technology workstation with the ability to control the duration of computer-simulated fluoroscopic exposure, thereby simulating an actual situation. METHODS: Sixty-three fellows and residents performed needle placement on the simulator. A virtual needle was percutaneously inserted into a virtual patient's thoracic spine derived from an actual patient computed tomography data set. RESULTS: Ten of 126 needle placement attempts by 63 participants ended in failure for a failure rate of 7.93%. From all 126 needle insertions, the average error (15.69 vs 13.91), average fluoroscopy exposure (4.6 vs 3.92), and average individual performance score (32.39 vs 30.71) improved from the first to the second attempt. Performance accuracy yielded P = .04 from a 2-sample t test in which the rejected null hypothesis assumes no improvement in performance accuracy from the first to second attempt in the test session. CONCLUSION: The experiments showed evidence (P = .04) of performance accuracy improvement from the first to the second percutaneous needle placement attempt. This result, combined with previous learning retention and/or face validity results of using the simulator for open thoracic pedicle screw placement and ventriculostomy catheter placement, supports the efficacy of augmented reality and haptics simulation as a learning tool.

A US-based survey on ventriculostomy practices.

BACKGROUND: The incidence of ICP monitoring has increased over the years and the indications for placement have expanded. Although ventriculostomy and ICP monitor placement are among the most commonly performed neurosurgical procedures, the current practice patterns have rarely been studied. METHODS: A 10-question survey was sent to 2006 neurosurgeons and 1060 neurosurgery residents in the US. Demographic information and data regarding estimated success rates of ventriculostomies, the steps taken in failure and use of technological aids used was sought. RESULTS: 479 neurosurgeons and 108 residents responded to our survey (response rates 23.9% and 10.2%, respectively). No catheter misplacements were reported by 19.8% respondents in the previous year whereas 2.2% reported misplacing more than 30%. With regards to ventriculostomy for patients with slit ventricles, image guidance was used by 51.7%; freehand technique was preferred by 41.6% and the Ghajar guide was used by 6.7% of respondents. We found that 56.9% of respondents abandoned free-hand placement after 3 failed passes. After abandoning free-hand cannulation, respondents used an ICP bolt or similar intra-parenchymal pressure monitoring device in trauma patients. Other approaches included leaving the catheter in place and readjusting it after repeating a CT scan. CONCLUSIONS: This survey sheds light on the current practice of ventriculostomy placement. Both residents and neurosurgeons admit to multiple attempts and frequent catheter misplacement. In order to consider a change in practice, respondents cited an increase in available data about guidance systems and ability to accommodate abnormal ventricular anatomy as primary requirements. A prospective study could help establish true evidence based practice for this common neurosurgical procedure.