Towards the target and not beyond: 2D vs 3D visual aids in MR-based neurosurgical simulation

Introduction: Urgent external ventricular drain (EVD) placement in aneurysmal subarachnoid hemorrhage (aSAH) is necessary for hydrocephalus treatment. However, it is unclear whether more rapid EVD placement is associated with better neurologic outcomes. In addition, EVD placement before aneurysm securement is thought to decrease aneurysmal transluminal pressure and may increase the risk of aneurysmal rerupture. We sought to better characterize whether the intervals from arrival to EVD placement and from EVD placement to aneurysm treatment were associated with differences in aneurysmal rerupture rates or neurologic outcomes. Methods: A retrospective study of a prospectively collected cohort of patients with aSAH presenting from 2015 to 2023 to a single academic center was performed. Multivariate logistic regressions (MLR) were performed to analyze the time from hospital arrival to EVD and both preprocedural aneurysm rerupture as well as poor neurologic outcomes, defined as a modified Rankin scale (mRS) >3 at 3 months. In addition, a similar analysis was performed with time from EVD to aneurysm securement. Results: Out of 434 patients with ruptured aSAH, we excluded those who received urgent craniotomy or craniectomy, as well as those who did not undergo angiography due to early mortality or EVD placement due to lack of hydrocephalus, resulting in a cohort of 231 patients (mean [SD] age, 57.6 [13.5]; 67.5% female, 69.3% white). Longer arrival to EVD was associated with an increased risk of preprocedural aneurysmal rerupture (OR 1.93, 95%CI 1.05, 3.66, p=0.038); however, longer EVD to aneurysm securement was not associated with differences in preprocedural aneurysmal rerupture (OR 0.66, 95%CI [0.41, 1.09], p=0.093). On MLR, longer arrival to EVD or longer EVD to aneurysm securement was not associated with differences in 3-month neurologic outcomes (OR 1.13, 95%CI [0.73, 1.75], p=0.6 and OR 0.74, 95%CI [0.51, 1.05], p=0.095, respectively). Conclusion: We found that longer arrival to EVD was associated with an increased risk of preprocedural rerupture, but not associated with differences in neurologic outcomes at 3 months. While EVD placement prior to aneurysmal securement is theorized to decrease transluminal pressure and increase rerupture risk, we did not find an association between duration from EVD placement to aneurysm securement and rerupture risk.

Timely ventriculostomy placement is critical in the management of neurosurgical emergencies. Prompt external ventricular drain (EVD) placement has been shown to improve long-term patient outcomes and decrease the length of ICU and hospital stays. Successful and efficient EVD placement requires seamless coordination among multiple healthcare teams. In this study, the authors sought to identify factors favoring delayed ventriculostomy via a quality improvement initiative and to implement changes to expedite EVD placement. Through process mapping, root cause analysis, and interviews with staff, the authors identified the lack of a standardized mechanism for alerting necessary healthcare teams as a major contributor to delays in EVD placement. In December 2019, an EVD alert system was developed to automatically initiate an EVD placement protocol and to alert the neurosurgery department, pharmacy, core laboratory, and nursing staff to prepare for EVD placement. The time to EVD placement was tracked prospectively using time stamps in the electronic medical record. A total of 20 patients who underwent EVD placement between December 2019 and April 2021, during the EVD alert protocol initiation, and 18 preprotocol control patients (January 2018 to December 2019) met study inclusion criteria and were included in the analysis. The mean time to EVD placement in the control group was 71.88 minutes compared with 50.3 minutes in the EVD alert group (two-tailed t-test, p = 0.025). The median time to EVD placement was 64 minutes in the control group compared with 52 minutes in the EVD alert group (rank-sum test, p = 0.0184). All patients from each cohort exhibited behavior typical of stable processes, with no violation of Shewhart rules and no special cause variations on statistical process control charts. A quality improvement framework helped identify sources of delays to EVD placement in the emergency department. An automated EVD alert system was a simple intervention that significantly reduced the time to EVD placement in the emergency department and can be easily implemented at other institutions to improve patient care.

The placement of an external ventricular drain (EVD) for the treatment of acute hydrocephalus is one of the most common life-saving procedures that neurosurgeons perform worldwide. There are many well-known complications associated with EVD placement, including tract hemorrhages, intra-parenchymal and subdural hemorrhages, infection, and catheter misplacement. Given the variety of complications associated with EVD placement and the inconsistent findings on the relationship of accuracy to complications, the present study reviewed short- and long-term complications related to EVD placement at our institution. A retrospective review was conducted for all consecutive patients who underwent bedside EVD placement for any indication between December 2020 and December 2021. Collected variables included demographic information, etiology of disease state, pre-and post-operative head computed tomography measurements, and post-procedural metrics (immediate and delayed complications). A total of 124 patients qualified for inclusion in our study. EVDs that were non-functioning/exchanged were not significantly related to age, accuracy, ventriculomegaly, sex, disposition, laterality, type of EVD used, intraventricular hemorrhage (IVH), etiology, or Kakarla Grade (KG) (all P > 0.17). The need for a second EVD was similarly not related to age, accuracy, ventriculomegaly, sex, disposition, location, laterality, type of EVD used, IVH, etiology, or KG (all P > 0.130). Patients who died, however, were significantly more likely to have a second contralateral EVD placed (18.2% vs. 4.9% P = 0.029). We also found that left-sided EVDs were significantly more likely to fail within seven days of placement (29.4% vs 13.3%, P = 0.037; relative risk (RR) 1.93, 95% confidence interval: 1.09-3.43), unrelated to age, sex, etiology, type of EVD, IVH, location of the procedure, or accuracy (all P > 0.07). This remained significant when using a binary logistic regression to control for ventriculomegaly, accuracy, mortality, age, sex, and etiology (P = 0.021, B = 3.43). In our cohort, although a clear relationship between inaccuracy and complication rates was not found, our data did demonstrate that left-sided EVDs were more likely to fail within the immediate postoperative time point, and patients who died were more likely to have a second, contralateral EVD placed.

External ventricular drain (EVD) placement is often associated with complications; however, predictors of adverse outcomes after EVD placement are not well understood. This study aimed to identify predictors of EVD tract hemorrhage and to compare post-EVD hemorrhage rates between computer-assisted navigation and freehand technique EVD placement. This retrospective study included 147 consecutive patients who presented with increased intracranial pressure (ICP) requiring an EVD. Multivariable logistic regression was used to assess the relationship between predictors and adverse outcomes after EVD placement. The most common presenting pathologies in patients who had EVD placement were intraparenchymal hemorrhage (IPH) (43%) and subarachnoid hemorrhage (SAH) (28%). 14% of patients experienced EVD tract hemorrhage. Patients with platelet counts < 120 × 10³/µL (OR = 4.47, 95% CI = 1.01-20, p = 0.038), white blood cell counts < 11 × 10³/µL (OR = 3.3, 95% CI = 1.01–10.7, p = 0.048), and IPH (OR = 2.97, 95% CI = 1.06–10.7, p = 0.048) had increased risks of tract hemorrhage. The use of computer-assisted navigation did not reduce the risk of tract hemorrhage after EVD placement compared to the freehand technique. This study identified factors associated with increased risks of hemorrhage after EVD placement, which can help triage at-risk patients and reduce adverse outcomes of this procedure.

Background: Cerebrospinal fluid diversion may be necessary in the acute period after subarachnoid hemorrhage (SAH) if patients develop hydrocephalus. Though there is an opinion that certain ‘severe grade’ patients, e.g. Hunt and Hess (HH) grades 3-5, should have external ventricular drain (EVD) placement, regardless of hydrocephalus, there is no firm data, leaving the decision up to the judgement of the evaluating clinical team. Objective: We sought to measure changes in HH grades among grade 3-5 patients based on whether or not they had EVD placement. Methods: We prospectively collect demographic, clinical, and radiographic data on our SAH patients since January 2014. We selected HH grades 3-5 patients and compared admission and discharge HH grades among groups of patients who underwent EVD placement or surgical decompression within the first 24 hours and those who did not, using chi square test. Results: Among 54 total patients, there were 37 grades 3-5 patients (HH 3, n=26, 70.3%; HH 4, n=5, 13.5%; HH 5, n=6, 16.2%) in two groups: no EVD, n=22 (59.5%) and EVD, n=14 (37.8%, data unavailable for 1 patient). At discharge HH grades were: HH 1, n=10 (27%); HH 2, n=1 (2.7%); HH 3, n=10 (27%); HH 4, n=3 (8.1%); HH 5, n=1 (2.7%); dead, n=11 (29.7%); missing data, n=1. Mean age of 37 HH 3-5 patients was 58 years with no significant difference between the 2 groups. Hydrocephalus was seen in 11 of the 22 no EVD group and 13 of the 14 EVD group, p=0.007. Improvement in HH score between admission and discharge was seen in 10/14 EVD group, compared with 5/22 of the no EVD group, p=0.010. Worsening of HH score was found in 8/17 no EVD group (5 HH grade 5 patients excluded from this analysis), and 1 HH 4 patient (out of 14) in the EVD group, p=.014. Mortality occurred in 11/22 of the no EVD group (HH 3=5; HH 4-5=6) and 1/14 of the EVD group (HH 4, p=0.007). Conclusion: While the presence of hydrocephalus could potentially be a determinant in the decision to place EVDs among HH grades 3-5 patients, clinical change in patients who did not have an EVD placed occurred independently of hydrocephalus. Improvement of HH grade was more frequent, while its worsening was less common, among patients who underwent EVD or surgery within the first 24 hours. Mortality of HH grade 3 patients may also be impacted with EVD placement.

Background External ventricular drain (EVD) placement is frequently performed in neurosurgical patients to divert cerebrospinal fluid (CSF) and monitor intracranial pressure. The traditional practice is the tunneled EVD technique performed in the operating room. EVD insertion through a bolt in intensive care units has also been reported. We describe here the usage of a novel technique, the “ catheter-locking device -assisted” EVD placement, reporting our preliminary, observational single-center results. Methods From January to October 2021, 15 patients underwent a “catheter-locking device-assisted” EVD placement at our institute. For each of these patients, the following data were evaluated: (1) demographics, (2) etiology, (3) clinical presentation, (4) EVD complications, and (5) final clinical outcomes. Results Median age of our population was 64 years, with a female/male ratio of 2:1. Average Glasgow Coma Scale score on admission was 8. Each patient maintained the drainage for an average time of 14 days. None of the patients suffered from postoperative intracerebral hemorrhage, CSF leakage, catheter migration, or discontinuation of the drainage system; none developed signs of infection. Nine patients required a permanent CSF diversion system. Outcome was good in 14 patients. One patient died for the underlying disease. Conclusions The “catheter-locking device-assisted” EVD placement appears to be a safe and accurate alternative to both the standard tunneled and the bolt-assisted EVD insertion techniques. The use of this procedure may significantly reduce the incidence of the commonest EVD complications, though further investigation is required.

The external ventricular drain (EVD) placement is one of the most common neurosurgical procedures. This operation is performed by freehand technique in the majority of cases; therefore, the operator's experience plays an important role in success and possible morbidity of this procedure. To evaluate the accuracy and safety of EVD placement by junior neurosurgery residents and factors predicting accuracy of EVD placement. This is a prospective cohort study conducted at our academic medical center, between September 2017 and August 2018. All patients 18years or older who required EVD placement were included. The accuracy and complications of EVD placement were assessed in the first and second year resident cohorts as well as by their level of experience, using descriptive statistics. Univariate and multivariate models were used to assess predictive factors for optimal EVD. A total of 100 EVDs were placed in 100 patients during the study period. According to Kakarla classification, the catheter was optimally placed in 80% of cases. The first year residents had a significantly higher rate of suboptimal burr hole placement compared to the second year residents (66.7% versus 27.1%, p = 0.004). The trainees with less than 10 EVD placement experience also had a significantly higher rate of suboptimal burr hole placement (55.2% vs. 23.9%, p = 0.003), significantly longer duration of operation (43.1min ± 14.9SD vs 34.2min ± 9.6 p = 0.005), and significantly lower rate of optimal EVD location (85.9% versus 65.5%, p = 0.023). Optimal location of the burr hole was the only significant predictor of optimal EVD placement in multivariate analysis (OR 11.9, 95% CI 3.2-44.6, p < 0.001). Neurosurgery residents experience and optimal burr hole placement are the main predicators of accurate EVD placement.

External ventricular drain (EVD) placement is a critical, lifesaving procedure in cranial neurosurgery, often performed manually using anatomical landmarks that vary between individuals. This study evaluates the efficacy of a 3-dimensional (3D)-printed EVD training model designed to improve the accuracy of this procedure. Computed tomography scans from 3 patients were used to create 3D-printed head models with narrow, wide, and normal ventricles. Twenty-five neurosurgeons participated in a three-round training protocol: pre-training, training with neuronavigation and a standardized protocol, and post-training. The accuracy of EVD placement was measured using an optical navigation system, and participants' confidence levels were assessed through questionnaires. Training significantly enhanced EVD placement accuracy. Pre-training, only 55.3% of placements were intraventricular (Kakarla grade 1), which increased to 84.0% post-training ( P < .001). The distance to the ideal entry point improved from 5.8 mm (SD, ±3.7 mm) to 4.1 mm (SD, ±1.5 mm), and the distance to the target point improved from 12.6 mm (SD, ±5.8 mm) to 8.3 mm (SD, ±4.0 mm) ( P < .001 for both). The time to identify entry points and puncture the ventricles also improved significantly. Left-sided EVDs were more frequently misplaced. In addition, right-handed participants (n = 24) performed better when placing left-sided EVDs with their right hand. Participants with more than 6 years of experience were more likely to misplace the EVD and overestimate their placement accuracy compared with less experienced participants. Post-training, both experienced and less experienced neurosurgeons achieved similar success rates. Confidence in EVD placement and puncture direction significantly increased post-training. A standardized training protocol using a 3D-printed model significantly improves the accuracy and confidence of neurosurgeons in EVD placement. Regular training is recommended to maintain high clinical performance, emphasizing the need for standardized procedures and the use of neuronavigation for complex cases.

Bedside Iohexol Ventriculography for Patients with Obstructive Colloid Cysts: A Protocol to Identify Auto-Fenestration of the Septum Pellucidum

Background: To examine the association between external ventricular drain (EVD) placement, critical care utilization, complications, and clinical outcomes in hospitalized adults with spontaneous subarachnoid hemorrhage (SAH). Methods: A single-center retrospective study included SAH patients 18 years and older, admitted between 1 January 2014 and 31 December 2022. The exposure variable was EVD. The primary outcomes of interest were (1) early mortality (<72 h), (2) overall mortality, (3) improvement in modified-World Federation of Neurological Surgeons (m-WFNSs) grade between admission and discharge, and (4) discharge to home at the end of the hospital stay. We adjusted for admission m-WFNS grade, age, sex, race/ethnicity, intraventricular hemorrhage, aneurysmal cause of SAH, mechanical ventilation, critical care utilization, and complications within a multivariable analysis. We reported adjusted odds ratios (aORs) and 95% confidence intervals (CI). Results: The study sample included 1346 patients: 18% (n = 243) were between the ages of 18 and 44 years, 48% (n = 645) were between the age of 45–64 years, and 34% (n = 458) were 65 years and older, with other statistics of females (56%, n = 756), m-WFNS I–III (57%, n = 762), m-WFNS IV–V (43%, n = 584), 51% mechanically ventilated, 76% White (n = 680), and 86% English-speaking (n = 1158). Early mortality occurred in 11% (n = 142). Overall mortality was 21% (n = 278), 53% (n = 707) were discharged to their home, and 25% (n = 331) improved their m-WFNS between admission and discharge. Altogether, 54% (n = 731) received EVD placement. After adjusting for covariates, the results of the multivariable analysis demonstrated that EVD placement was associated with reduced early mortality (aOR 0.21 [0.14, 0.33]), an improvement in m-WFNS grade (aOR 2.06 [1.42, 2.99]) but not associated with overall mortality (aOR 0.69 [0.47, 1.00]) or being discharged home at the end of the hospital stay (aOR 1.00 [0.74, 1.36]). EVD was associated with a higher rate of ventilator-associated pneumonia (aOR 2.32 [1.03, 5.23]), delirium (aOR 1.56 [1.05, 2.32]), and a longer ICU (aOR 1.33 [1.29;1.36]) and hospital length of stay (aOR 1.09 [1.07;1.10]). Critical care utilization was also higher in patients with EVD compared to those without. Conclusions: The study suggests that EVD placement in hospitalized adults with spontaneous subarachnoid hemorrhage (SAH) is associated with reduced early mortality and improved neurological recovery, albeit with higher critical care utilization and complications. These findings emphasize the potential clinical benefits of EVD placement in managing SAH. However, further research and prospective studies may be necessary to validate these results and provide a more comprehensive understanding of the factors influencing clinical outcomes in SAH.

Assessing survival and learning curves for EVD procedures in hemorrhagic stroke patients in a New York City hospital

External ventricular drain (EVD) placement is one of first cranial procedures neurosurgery residents are expected to perform independently. While proper training improves patient outcomes, there are few options for practicing EVD placement prior to placing the EVD in patients in a clinical setting. Proposed solutions to this include using cadaveric models and virtual simulations, but barriers exist with these as well in regard to authenticity. EVD simulators using virtual reality technologies are a promising new technique for training, but the cost of these devices poses a barrier to general/widespread accessibility among smaller programs or underserved hospitals. The authors desribe a novel, yet simple, and cost-effective technique (less than $5 per mold) for developing a brain model constructed of homemade ballistics gelatin that can be used for teaching and practicing the placement of EVD. A brain model is made with ballistics gelatin using an anatomically correct skull model as a mold. A 3D-printed ventricular system model is used to create a mold of an anatomically correct ventricular system in the brain model. A group of medical students (n = 10) were given a basic presentation about EVD placement, including standard landmarks and placement techniques, and were also shown a demonstration of EVD placement on the brain model. They were then allowed to perform an EVD placement using the brain model. The students were surveyed on their experience with using the brain model, including usability and practicality of the model. Accuracy of EVD placement by each student was also assessed, with adequate position of catheter tip being in the ipsilateral frontal horn. The final product is fairly inexpensive and easy to make. It is soft enough to pass a catheter through, but it is also firm enough to maintain its shape, including a cavity representing the lateral ventricles. The dense gelatin holds the catheter in its final resting position, while the two halves are separated and inspected. All participants in the test group of medical students reported that the brain model was easy to use, helped them understand the steps and technique of EVD placement, and provided good feedback on the ideal position of ventricular catheters. All of the participants in the group had adequate positioning of their ventricular catheters after one attempt. The presented brain model is easy to replicate, inexpensive, anatomically accurate, and provides a medium for neurosurgeons to teach and practice ventricular catheter placement in a risk-free environment.

External ventricular drain (EVD) placement is the most commonly performed bedside emergent neurosurgical procedure. However, catheter misplacement occurs in approximately 25% of cases, potentially resulting in neurological injury or the need for repositioning, highlighting the need for safer and more accurate placement techniques. This review aims to (1) summarize technological innovations developed to enhance the accuracy and safety of bedside EVD placement, (2) evaluate their reported benefits and limitations, and (3) identify key barriers to their clinical implementation in critical care settings. We conducted a systematic review of PubMed, Embase, and Scopus combining terms related to EVD placement and assistive technologies. All the studies evaluated EVD placement using simulations, phantoms, cadavers, and patient procedures conducted at the bedside and in the operating room. We identified 3898 records, and 76 studies met the inclusion criteria. Of these, 30 studies compared stereotactic systems, ultrasound guidance, frameless neuronavigation, and augmented or mixed reality technologies to the freehand technique. These studies consistently reported improved accuracy with advanced systems although complication rates and procedural times were variably reported. An additional 35 and 12 studies evaluated nonimmersive and immersive technologies, respectively, in noncomparative settings. Most of these demonstrated high first-pass success and mean tip deviations under 3 mm. Variability in the definitions of accuracy and procedural metrics limited data synthesis, but the overall findings suggest a promising trajectory for technology-assisted EVD placement. Assistive technologies for EVD placement show potential to improve accuracy and safety over the freehand technique. These early successes signal potential to improve bedside neurosurgical care. Realizing this promise will require future studies to standardize accuracy metrics, report time, and safety outcomes consistently and validate performance in real-world critical care settings.

Decreasing External Ventricular Drain Infection Rates in the Neurocritical Care Unit: 12-Year Longitudinal Experience at a Single Institution

Iatrogenic Intracranial Aneurysm After External Ventricular Drain Placement: Traumatic or Mycotic Origin? Case Report and Literature Review