Improving Successful Cannulation of External Ventricular Drain: 3D-Printed Surgical Guide for Inexperienced Neurosurgeons

OBJECTIVE

External ventricular drain (EVD) is a fundamental neurosurgical procedure that is commonly performed by junior neurosurgeons. Expedient, successful cannulation of the ventricles can be lifesaving. Yet, the free-hand technique of EVD insertion is associated with significant malpositioning rates. This study aimed to improve EVD placement by junior neurosurgeons with the aid of a customized 3D-printed surgical guide.

METHODS

A 3D-printed surgical guide was developed and customized to our institution's EVD insertion procedure. First-year neurosurgical residents were taught how to perform preoperative trajectory planning based on coronal brain images and how to use the surgical guide during the standard EVD insertion procedure. Number of passes, accuracy of EVD placement, operative complications, need for revision, and surgeon's experience with the guide were recorded.

RESULTS

First-year neurosurgical residents performed guide-assisted EVD insertion in 14 patients. Significantly, 6 (43%) patients had ventricular anatomy distorted by midline shift. All surgeons achieved successful ventricular cannulation using the EVD guide on first pass (100%). Of 14 guide-assisted EVDs, 13 (93%) were optimally placed (Kakarla grade 1). Only 1 (7%) guide-assisted EVD was suboptimally placed (Kakarla grade 2). There were no intraoperative or postoperative complications and no EVD revisions.

CONCLUSIONS

For inexperienced surgeons, the 3D-printed EVD guide can improve ventricular cannulation even in cases of altered ventricular anatomy. The use of 3D printing would also allow the guide to be widely adopted by other institutions worldwide.

How do I do it? Real-time three-dimensional robotic C-arm navigation for ventriculoperitoneal shunting

BACKGROUND

Ventriculoperitoneal (VP) shunts are commonly used for managing hydrocephalus, with mechanical dysfunction being the most common cause of complications that require revision. A VP shunt placed using a real-time three-dimensional (3D) robotic C-arm navigation system may have better outcomes and fewer complications.

METHODS

In this technical note, we introduced the workflow of the use of the real-time 3D robotic C-arm navigation system for ventriculoperitoneal shunting.

CONCLUSION

The real-time 3D robotic C-arm can provide a more precise approach to the target. Furthermore, this technique may lower the risk of complications and increase the success rate of shunt placements.

Development of an Evidence-based Care Bundle for Prevention of External Ventricular Drain-related Infection: Results of a Single-center Prospective Cohort Study and Literature Review

Background

External ventricular drain (EVD)-related infection (ERI) is a common complication in cranial neurosurgery practice with high mortality. The risk factors associated with ERI are not well studied in low- and middle-income countries (LMIC) like India. Identifying the risk variables is a necessity to design robust evidence-based care bundles for ERI prevention.

Materials and methods

This is a single-center prospective cohort study. Patients with and without ERI during the 2-year study period were analyzed along with literature review to identify the risk variables associated with ERI. The Institute for Healthcare Improvement (IHI) comprehensive flowchart was used to develop the concept care bundle for ERI prevention.

Results

A total of 211 EVD were inserted during the study period. 15 ERI (7.1%) were identified based on IDSA criteria, with an average infection rate of 11.12 per 1000 EVD days. Gram negative bacteria (GNB) were the predominant pathogen (12/15, 80%), with Klebsiella pneumoniae (6/15, 40%) being the most common bacteria isolated. In multivariate analysis, the risk variables associated with ERI were use of broad spectrum pre-surgical antimicrobial prophylaxis for long duration, choice of posterior craniometric points for EVD insertion, EVD duration >7 days, EVD leak and surveillance cerebrospinal fluid (CSF) sampling at periodic intervals. Based on the risk variables identified in this study and literature review, a consensus decision on the care elements for the insertion and maintenance phases was chosen for the concept care bundle for ERI prevention.

Conclusion

An evidence-based concept care bundle for ERI prevention is proposed for further multicentric evaluation and validation.

How to cite this article

Ponnambath DK, Divakar G, Mamachan J, Biju S, Raja K, Abraham M. Development of an Evidence-based Care Bundle for Prevention of External Ventricular Drain-related Infection: Results of a Single-center Prospective Cohort Study and Literature Review. Indian J Crit Care Med 2024;28(8):760-768.

Ventriculoperitoneal shunt entry points in patients undergoing shunt placement: A single-center study

Background

The ventriculoperitoneal (VP) shunt redirects cerebrospinal fluid flow, with the selection of entry points crucial for optimal outcomes. Anatomical landmarks and specific entry points, such as Kocher's, Frazier's, Keen's, and Dandy's points, have been utilized for shunt catheter placement. This study investigates the impact of various entry points on outcomes, particularly the necessity for revision procedures, in patients undergoing VP shunt placement.

Methods

In this retrospective cohort study, we analyzed data from patients in our center's database, collected from October 2017 to October 2022. Participants were classified based on ventriculoperitoneal shunt entry points. The study followed STROBE guidelines. Continuous variables were presented as means with standard deviations (SD) and categorical variables as frequencies and percentages. Linear Model ANOVA and Pearson's Chi-squared tests were used for comparisons. Data analysis was conducted using Jamovi software.

Results

Our study included 94 patients who underwent shunt procedures. The patients were categorized into four treatment groups: Dandy point (10), Frazier point (21), Keen point (43), and Kocher point (20).

Conclusion

Our study found no significant differences in age, FOHR, and indication for shunt placement among catheter entry point subgroups. However, gender distribution, catheter length, and catheter tip location significantly varied. The proportion of patients requiring revision surgery varied among the groups, with the highest rate in the Dandy point group and the lowest in the Keen group; however, the difference among the entry groups was insignificant.

Ventricular Access Utilizing Cutaneous Reference Points: Statistical Analysis and Proposal of a New Ventricular Entry Point

OBJECTIVES

Perform radiologic measurements and analysis of normal brain computed tomography (CT) scans; delineate a new ventricular entry point from cutaneous landmarks, highlighting the potential surgical implications of these findings.

METHODS

Six radiologic distances (AR; BR; AL; BL, C, and D) were measured in normal brain CT scans using Horos software. Statistical analysis of the measurements was performed with minitab18 software based on age, sex, and side.

RESULTS

132 brain CT scans were analyzed, yielding the following mean results: AR distance: 2.1 cm; BR distance: 7 cm; AL distance: 2.1 cm; BL distance: 7.1 cm; C distance: 12.4 cm; D distance: 7 cm; new ventricular entry point: 12.4 cm posterior to the nasion, and 2.1 cm lateral to the midline.

CONCLUSIONS

The freehand technique for accessing the lateral ventricles is a common neurosurgical procedure but is often accompanied by complications. To address this, we suggest a novel entry point for ventricular access, determined by cutaneous reference points. This point is situated 12.4 cm posterior to the nasion along the midline and 2.1 cm lateral to the midline. Although our findings may play a role in presurgical planning for ventricular pathologies, future prospective studies are warranted.

Combined depth and scalp electroencephalographic monitoring in acute brain injury: Yield and prognostic value

BACKGROUND AND PURPOSE

Depth electroencephalography (dEEG) is an emerging neuromonitoring technology in acute brain injury (ABI). We aimed to explore the concordances between electrophysiological activities on dEEG and on scalp EEG (scEEG) in ABI patients.

METHODS

Consecutive ABI patients who received dEEG monitoring between 2018 and 2022 were included. Background, sporadic epileptiform discharges, rhythmic and periodic patterns (RPPs), electrographic seizures, brief potentially ictal rhythmic discharges, ictal-interictal continuum (IIC) patterns, and hourly RPP burden on dEEG and scEEG were compared.

RESULTS

Sixty-one ABI patients with a median dEEG monitoring duration of 114 h were included. dEEG significantly showed less continuous background (75% vs. 90%, p = 0.03), higher background amplitude (p < 0.001), more frequent rhythmic spike-and-waves (16% vs. 3%, p = 0.03), more IIC patterns (39% vs. 21%, p = 0.03), and greater hourly RPP burden (2430 vs. 1090 s/h, p = 0.01), when compared to scEEG. Among five patients with seizures on scEEG, one patient had concomitant seizures on dEEG, one had periodic discharges (not concomitant) on dEEG, and three had no RPPs on dEEG. Features and temporal occurrence of electrophysiological activities observed on dEEG and scEEG are not strongly associated. Patients with seizures and IIC patterns on dEEG seemed to have a higher rate of poor outcomes at discharge than patients without these patterns on dEEG (42% vs. 25%, p = 0.37).

CONCLUSIONS

dEEG can detect abnormal electrophysiological activities that may not be seen on scEEG and can be used as a complement in the neuromonitoring of ABI patients.

Intraventricular haemorrhage treated by extra ventricular drainage with catheter mistakenly penetrating the cisterna ambiens: A case report

Intraventricular haemorrhage (IVH) is a severe and acute type of stroke with a complex pathophysiology and is a therapeutic challenge. This case report described a man in his early 50's diagnosed with IVH by computed tomography (CT). Although bilateral extraventricular drainage (EVD) was undertaken, a postoperative CT scan showed that while the left catheter was correctly positioned, the right catheter had been wrongly inserted into the cisterna ambiens. The procedure was equivalent to simultaneous EVD combined with cisternostomy. As a consequence, the haematoma was rapidly removed, the risk of infection and long-term hydrocephalus was reduced, and prognosis was improved. Large case-control studies or prospective studies are needed to evaluate the safety and effectiveness of this treatment modality.

Epidemiology, clinical profile, and outcomes of CSF-diversion catheter-related infections - Prospective cohort study results from a single quaternary neurosurgery referral centre

BACKGROUND

Device-associated CNS infections is a major subgroup of healthcare associated CNS infections. Healthcare-associated ventriculitis or meningitis differs considerably from community-acquired meningitis in its epidemiology, pathogenesis, clinical presentation and management.

OBJECTIVES

This study aimed to identify the infection rates, the associated risk factors, and outcomes of these life-threatening infections.

METHODS

This was a 2-year single center prospective cohort study. Patient's clinical data, laboratory parameters, treatment and their outcomes were collected using data collection tool, and device days were collected from the hospital information system (HIS). Patients were categorised using IDSA criteria as contamination or colonisation or infection. Cox regression model was used for multivariate analysis to estimate hazard risk.

RESULTS

A total of 578 CSF diversion catheters were inserted in 472 patients. The average rate for EVD and LD infection were 11.12 and 11.86 per 1000 device days respectively. The average infection rates for VP and LP shunts were 6% and 5.2% per procedure, respectively. The commonest etiological agent causing CSF diversion catheter-related infection (CDRI) was Klebsiella pneumoniae (n = 14, 40%). The risk factors which were independently associated with increased infection risk by cox regression analysis were drain insertion ≥7 days [HR:11.73, p -0.03], posterior approach of EVD insertion (occipital) [HR:9.53, p - 0.01], pre-OP ASA score>3 [HR:8.28, p - 0.013] presence of EVD/LD leak [HR: 17.24, p < 0.0001], male gender [HR:2.05, p-0.05] and presence of associated peri-operative scalp infections [HR:3.531, p-0.005]. Shift to narrow spectrum surgical prophylactic antibiotic [Coefficient: -1.284, p-0.03] and reduction in CSF sampling frequency [Coefficient: -1.741, p-0.02] were found to be negatively associated with CDRI.

CONCLUSIONS

The study demonstrated drain insertion ≥7 days, posterior approach of EVD insertion, presence of EVD/LD leak, male gender and presence of associated peri-operative scalp skin and soft tissue infections were associated with increased risk of infection.

Ventriculo-atrial shunt with occlusion of the internal jugular vein: operative experience and surgical technique

BACKGROUND

Ventricular shunts are one of the most frequent techniques used for the management of hydrocephalus. The ventriculoperitoneal shunt (VPS) is the most commonly performed procedure, and the ventriculoatrial shunt (VAS) is the second option in most medical centers. The main objective of this study is to introduce and describe a surgical approach for VAS outlining our experience and comparing it with traditional shunting techniques.

METHODS

In this retrospective cohort comparison study, we included patients with hydrocephalus treated with a surgical procedure between January 2010 and February 2021 at a single academic institution. We categorized the procedures into two groups: patients with VPS and conventional VAS grouped together into the conventional technique (CT) group, and the second group was patients with whom we performed VAS with complete internal jugular vein occlusion (IJVOT). We compared the surgical time, postoperative complications, and occurrence of shunt failure among the groups by performing univariate analysis using the Fisher exact test.

RESULTS

Out of the 106 patients included in the analysis, IJVOT was performed in 66 patients, and CT in 40 patients. The median surgical time was 60 min (IQR 60-90) for IJVOT versus 100 min (IQR 60-120) for CT (p < 0.01). In the follow-up a month after the procedure, 83.3% of patients with IJVOT and 62.5% of patients with CT did not require shunt removal or shunt revision (p < 0.01). Shunt revision rates were 12.5% and 1.5% for CT while 1.5% and 2.5% for IJVOT at 1 and 6 months after the procedure.

CONCLUSION

Our findings demonstrate that VAS with IJVOT is a safe method that exhibited shorter surgical times and outcomes comparable to CT. However, since the present study represents the first cohort evaluating IJVOT, it is imperative to conduct larger prospective studies, along with clinical trials, to fully explore and establish efficacy, long-term outcomes, and an in-depth comparison among shunting techniques.

The Technique for Transorbital Ventricular Puncture: An Anatomic Approach

BACKGROUND AND OBJECTIVES

Transorbital ventricular puncture is a minimally invasive described procedure with poor landmarks and anatomic references. This approach can be easily performed to save patients with intracranial hypertension, especially when it is secondary to an acute decompensated hydrocephalus. This study aims to describe anatomic structures and landmarks to facilitate the execution of transorbital puncture in emergency cases.

METHODS

We analyzed 120 head computed tomographies to show the best area to perform the procedure in the orbital roof. Two adult cadavers (4 sides) were punctured in the predetermined area. Angles, distances, landmarks, and anatomic structures were registered. This approach to the ventricular system may be performed at bedside to relieve intracranial hypertension only in specific cases.

RESULTS

The perforation point is 2.5 cm (female) or 3.0 cm (male) lateral to the midline and immediately inferior to the superciliary arch. A vertical line, parallel to midline, was drawn on the outer edge of the patient's forehead, the needle was 45° inferiorly and 20° medially and then progressed 2.0 cm backwards to reach the bone perforation point. After that, it was advanced another 4.5cm approximately until it reached the anterior horn of the lateral ventricle.

CONCLUSION

Based on statistical and experimental evidences, we were able to establish reliable anatomic reference points to access the anterior horn of the lateral ventricle through transorbital puncture.

The incidence of VP shunt infection in a middle-income nation: a retrospective analysis of a pediatric population

Objective

To investigate the incidence of infection after ventriculoperitoneal shunt (VPS) insertion at the Bustamante Hospital for Children (BHC), Jamaica, West Indies.

Method

Of the 178 patients managed by the Neurosurgery team at BHC, who underwent surgery between 2010 and 2016, 122 patients were subjected to the cerebrospinal fluid (CSF) diversion procedure through a VPS placement. The patients excluded from this study included those with a VPS placed at another institution or one placed prior to the study period. There is a notable transition that saw a switch from the use of the Codman uni-port to Medtronic shunts in 2014-2015, which initiated the process of reuse of shunt passers. Clinical data were retrospectively collected from operating theater logs and available manual health records.

Results

Over the 7-year study period of the 122 first-time shunt placements done, 17 patients (13.9%) had positive CSF cultures, with an additional six (4%) having CSF pleocytosis with negative cultures. The most common isolate was the Staphylococcus species, occurring in 60% of VPS infections. The median time to shunt infection was 2 months. Of the 72 Codman shunts placed, six became infected, and 21.7% (10 of 46) of the Medtronic shunts became infected.

Conclusion

The rate of incidence of VPS infection was 13.9% for the period between 2010 and 2016, with most infections occurring after 2014. The major causative agent was Staphylococcus species at 60% within a median 2 months of surgery. Overall, this compares well with data reported in the literature.

How I do it: brainwashing for purulent ventriculitis

BACKGROUND

The management of ventriculitis remains controversial, with no single management strategy that can provide a good outcome. There are few articles describing the brainwashing technique, and most for neonatal intraventricular hemorrhage. This technical note is important because it describes a practical way to perform brainwashing in case of ventriculitis, and it is more feasible compared to endoscopic lavage in developing countries.

METHOD

We describe in a stepwise fashion the surgical technique of ventricular lavage.

CONCLUSION

Ventricular lavage is a neglected technique that can help to improve ventricular infection and hemorrhage prognosis.

Revisiting the transorbital approach for emergency external ventricular drainage: an anatomical study of relevant parameters and their effect on the effectiveness of using Tubbs' point

The transorbital approach (TOA) can provide immediate access to the lateral ventricles by piercing the roof of the orbit (ROO) with a spinal needle and without the need of a drill. Reliable external landmarks for the TOA ventriculostomy have been described, however, the necessary spinal needle gauge and other relevant parameters such as the thickness of the ROO have not been evaluated. Nineteen formalin-fixed adult cadaveric heads underwent the TOA. Spinal needles of different gauges were consecutively used in each specimen beginning with the smallest gauge until the ROO was successfully pierced. The thickness of the ROO at the puncture site and around its margins was measured. Other parameters were also measured. The TOA was successfully performed in 14 cases (73.68%), where the most suitable needle gauge was 13 (47.37%), followed by a 10-gauge needle (36.84%). The mean thickness of the ROO at the puncture site, and the mean length of the needle to the puncture site were 1.7 mm (range 0.2-3.4 mm) and 15.5 mm (range 9.2-23.4 mm), respectively. A ROO thickness of greater than 2.0 mm required a 10-gauge needle in seven cases, and in five cases, a 10-gauge needle was not sufficient for piercing the ROO. The presence of hyperostosis frontalis interna (HFI) (21.05%) was related to the failure of this procedure (80%; p < 0.00). Using a 13/10-gauge spinal needle at Tubbs' point for TOA ventriculostomy allowed for external ventricular access in most adult specimens. The presence of HFI can hinder this procedure. These findings are important when TOA ventriculostomy is considered.

The accuracy and safety of intraoperative ultrasound-guided external ventricular drainage in intraventricular hemorrhage

Severe IVH often results in a poor outcome. Currently, EVD is a standard treatment for IVH, but there is little research to show whether using ultrasound to guide the catheter placement improves outcome. Patients with severe IVH who had iUS-guided EVD (the iUS-guided group) were enrolled retrospectively and compared with a group who had EVD performed without ultrasound guidance (the control group) from January 2016 to July 2022. Data were collected on accuracy of the catheter placement, complications and outcome at 3 months assessed by mRS. The accuracy of the EVD placement was classified as optimal placement, sub-optimal placement and misplacement according to the position of the catheter tip. The complications reported are catheter-related hemorrhage, intracranial infection and hydrocephalus. There were 105 cases enrolled, with 72 patients in the iUS-guided group having 131 catheters inserted and 33 patients in the group where ultrasound was not used with a total of 59 catheters. 116 (88.55%) were optimally placed, 12 (9.16%) sub-optimal and 3 (2.29%) misplaced in the iUS-guided group, while 25 (42.37%) were in optimally placed, 30 (50.85%) sub-optimal and 4(6.78%) misplaced in the control group. Accuracy of placement was highly significantly improved using ultrasound (P < 0.001). The operation time and the average catheterized time were longer in the iUS-guided group (P < 0.05), but the complication rates were no different between the groups. The mRS at three months was not significantly different between the two groups. Using iUS to place EVD catheters in patients with severe IVH is a safe technique delivering more accurate catheter placement without increasing the complication rate compared with freehand placement.

External ventricular drains and risk of freehand placement: A systematic review and meta-analysis

OBJECTIVE

External ventricular drains (EVDs) are used to monitor and treat elevated intracranial pressure. EVDs are often placed blindly without the use of imaging guidance, and successful placement with respect to pass attempts and final catheter location may suffer as a result of this freehand technique.

METHODS

A systematic literature search was conducted in PubMed, Embase, Web of Science, and Cochrane databases to identify studies pertaining to freehand EVD placement through March 30, 2022. Studies were included if they reported percentage of EVDs placed successfully on the first pass attempt, or final catheter location as defined by the Kakarla Grading System. Pooled weighted incidence estimates and 95% confidence intervals (95%CI) were calculated using a random effects model.

RESULTS

Of the 2964 results returned from the literature search, 39 studies were included in this meta-analysis. These studies reported on 6313 EVDs placed via freehand technique in 6070 patients with the following respective incidence: successful EVD placement on the first attempt (78%, 95%CI: 67-86%); placement with a Kakarla Grade of 1 (optimal location) (72%, 95%CI: 66-77%); hemorrhage (7%, 95%CI: 6-10%), and infection (5%, 95%CI: 3-8%).

CONCLUSIONS

Only 78% of EVDs in this meta-analysis were placed successfully on the first pass, and only 72% of final placements were deemed optimal. This represents a relatively high rate of suboptimal outcomes with respect to EVD placement, which could potentially be avoided with the use of navigation-assisted placement techniques.

Supratentorial cerebrospinal fluid diversion using image-guided trigonal ventriculostomy during retrosigmoid craniotomy for cerebellopontine angle tumors

Background

Cerebellar contusion, swelling and herniation is frequently encoutered upon durotomy in patients undergoing retrosigmoid craniotomy for cerebellopontine angle (CPA) tumors, despite using standard methods to obtain adequate cerebellar relaxation.

Objective

The aim of this study is to report an alternative cerebrospinal fluid (CSF)-diversion method using image-guided ipsilateral trigonal ventriculostomy.

Methods

Single-center retro- and prospective cohort study of n = 62 patients undergoing above-mentioned technique. Prior durotomy, CSF-diversion was performed to the point where the posterior fossa dura was visibly pulsatile. Outcome assessment consisted of the surgeon's intra- and postoperative clinical observations, and postoperative radiological imaging.

Results

Fifty-two out of n = 62 (84%) cases were eligible for analysis. The surgeons consistently reported successful ventricular puncture and a pulsatile dura prior durotomy without cerebellar contusion, swelling or herniation through the dural incision in n = 51/52 (98%) cases. Forty-nine out of n = 52 (94%) catheters were placed correctly within the first attempt, with the majority of catheter tips (n = 50, 96%) located intraventricularly (grade 1 or 2). In n = 4/52 (8%) patients, postoperative imaging revealed evidence of a ventriculostomy-related hemorrhage (VRH) associated with an intracerebral hemorrhage [n = 2/52 (4%)] or an isolated intraventricular hemorrhage [n = 2/52 (4%)]. However, these hemorrhagic complications were not associated with neurological symptoms, surgical interventions or postoperative hydrocephalus. None of the evaluated patients demonstrated radiological signs of upward transtentorial herniation.

Conclusion

The method described above efficiently allows CSF-diversion prior durotomy to reduce cerebellar pressure during retrosigmoid approach for CPA tumors. However, there is an inherent risk of subclinical supratentorial hemorrhagic complications.

Improved Accuracy and Lowered Learning Curve of Ventricular Targeting Using Augmented Reality-Phantom and Cadaveric Model Testing

BACKGROUND

Augmented reality (AR) has demonstrated significant potential in neurosurgical cranial, spine, and teaching applications. External ventricular drain (EVD) placement remains a common procedure, but with error rates in targeting between 10% and 40%.

OBJECTIVE

To evaluate Novarad VisAR guidance system for the placement of EVDs in phantom and cadaveric models.

METHODS

Two synthetic ventricular phantom models and a third cadaver model underwent computerized tomography imaging and registration with the VisAR system (Novarad). Root mean square (RMS), angular error (γ), and Euclidian distance were measured by multiple methods for various standard EVD placements.

RESULTS

Computerized tomography measurements on a phantom model (0.5-mm targets showed a mean Euclidean distance error of 1.20 ± 0.98 mm and γ of 1.25° ± 1.02°. Eight participants placed EVDs in lateral and occipital burr holes using VisAR in a second phantom anatomic ventricular model (mean RMS: 3.9 ± 1.8 mm, γ: 3.95° ± 1.78°). There were no statistically significant differences in accuracy for postgraduate year level, prior AR experience, prior EVD experience, or experience with video games ( P > .05). In comparing EVDs placed with anatomic landmarks vs VisAR navigation in a cadaver, VisAR demonstrated significantly better RMS and γ, 7.47 ± 0.94 mm and 7.12° ± 0.97°, respectively ( P ≤ .05).

CONCLUSION

The novel VisAR AR system resulted in accurate placement of EVDs with a rapid learning curve, which may improve clinical treatment and patient safety. Future applications of VisAR can be expanded to other cranial procedures.

A comparison of ventricular volume and linear indices in predicting shunt dependence in aneurysmal subarachnoid hemorrhage

Background

Guidelines for determining shunt dependence after aneurysmal subarachnoid hemorrhage (aSAH) remain unclear. We previously demonstrated change in ventricular volume (VV) between head CT scans taken pre- and post-EVD clamping was predictive of shunt dependence in aSAH. We sought to compare the predictive value of this measure to more commonly used linear indices.

Methods

We retrospectively analyzed images of 68 patients treated for aSAH who required EVD placement and underwent one EVD weaning trial, 34 of whom underwent shunt placement. We utilized an in-house MATLAB program to analyze VV and supratentorial VV (sVV) in head CT scans obtained before and after EVD clamping. Evans' index (EI), frontal and occipital horn ratio (FOHR), Huckman's measurement, minimum lateral ventricular width (LV-Min.), and lateral ventricle body span (LV-Body) were measured using digital calipers in PACS. Receiver operating curves (ROC) were generated.

Results

Area under the ROC curves (AUC) for the change in VV, sVV, EI, FOHR, Huckman's, LV-Min., and LV-Body with clamping were 0.84, 0.84, 0.65, 0.71.0.69, 0.67, and 0.66, respectively. AUC for post-clamp scan measurements were 0.75, 0.75, 0.74, 0.72, 0.72, 0.70, and 0.75, respectively.

Conclusion

VV change with EVD clamping was more predictive of shunt dependence in aSAH than change in linear measurements with clamping and all post-clamp measurements. Measurement of ventricular size on serial imaging with volumetrics or linear indices utilizing multidimensional data points may therefore be a more robust metric than unidimensional linear indices in predicting shunt dependence in this cohort. Prospective studies are needed for validation.

Invasive Neuromonitoring in the Stroke Patient

With advances in technology, the options to manage patients with neurologic injuries are often complex. Critical care management of neurologic injury has historically focused on the prevention of secondary ischemic injury through aggressive management of intracranial pressure (ICP) and maintenance of adequate cerebral perfusion pressure (CPP). However, ICP monitoring alone does not identify ischemic changes that herald patient deterioration. Advocates of multimodality monitoring cite the value of early detection of changes in brain oxygenation levels and brain metabolism as advantageous in optimizing stroke outcomes. ICP monitoring alone should not be the sole source of information on which therapy is guided but should be incorporated into the arsenal of emerging and promising invasive neuromonitoring devices.

An overview of clinical cerebral microdialysis in acute brain injury

Cerebral microdialysis may be used in patients with severe brain injury to monitor their cerebral physiology. In this article we provide a concise synopsis with illustrations and original images of catheter types, their structure, and how they function. Where and how catheters are inserted, their identification on imaging modalities (CT and MRI), together with the roles of glucose, lactate/pyruvate ratio, glutamate, glycerol and urea are summarized in acute brain injury. The research applications of microdialysis including pharmacokinetic studies, retromicrodialysis, and its use as a biomarker for efficacy of potential therapies are outlined. Finally, we explore limitations and pitfalls of the technique, as well as potential improvements and future work that is needed to progress and expand the use of this technology.

Ecce Homo: Moving past labels to lives

OBJECTIVES

We report a contemporary individual who died with advanced holoprosencephaly (HPE) to encourage recognition of rare diseases (RDs), especially congenital conditions in archaeological samples. We also explore the range of conditions associated with hydrocephalus in support of nuanced interpretations of this disease.

MATERIALS

The skeleton of a 17-year-old male who died with clinically diagnosed HPE, along with an age and sex matched comparative sample of 6 individuals who suffered accidental death and who were normal.

METHODS

We observed and measured all remains using standard osteological methods. The clinical records for Ecce Homo were scrutinized; his family was interviewed, and his skull was X-rayed.

RESULTS

The morphology and morphometry of Ecce Homo's skeleton display irregularities along the cranial midline and the postcranial skeleton consistent with anomalies derived from HPE as well as related congenital disorders and physical anomalies.

CONCLUSIONS

We have reported HPE here and developed a differential diagnosis with closely related conditions. Likewise we relate the information generated in the clinical history and interviews with the family of Ecce Homo to facilitate an understanding of the social context.

SIGNIFICANCE

This case is exceptional in providing information from the life context of a contemporary individual who suffered from a rare disease (HPE), with skeletal remains could be studied extensively. The differential diagnosis is useful in identifying HPE and other closely related conditions.

LIMITATIONS

This is a single example with clinical intervention.

SUGGESTIONS FOR FURTHER RESEARCH

Future osteological research should occur on other cases of HPE; molecular studies may offer further clarity.

Ventricular Catheter Insertion on the Occipital and Parietooccipital Bone: A Nonmetric Complementary Technique

Background and Study Aim Hydrocephalus is a common disease of the pediatric population, with cerebrospinal fluid diversion as the management of choice. All current insertion techniques require craniometrics calculation that may not be applicable for pediatric patients, due to significant variation in head circumference. We describe a complementary method of inserting ventricular catheters, devoid of craniometrics.

Materials and Methods The insertion site is based on two imaginary lines on the sagittal plane (superior and inferior limits) and four imaginary lines on the axial plane of a computed tomography/magnetic resonance imaging. The insertion point is chosen based on the shortest location from the outer table of the bone to the ventricle. The length of catheter insertion is calculated based on the distance between the calvarial outer table and the foramen of Monro.

Results Two case examples of ventricular catheter insertions, in pediatric patients with noncommunicating hydrocephalus, are described. External ventricular drain and ventriculoperitoneal shunt were inserted using this technique, with no required craniometrics measurements.

Conclusion This complementary method of inserting ventricular catheters can be easily tailored and implemented by junior neurosurgical residents to senior neurosurgeons as it precludes the measurement of the catheter insertion points.

Closure intracranial pressure is an objective intraoperative determinant of the adequacy of surgical decompression in traumatic acute subdural haematoma: a multicentre observational study

PURPOSE

Acute subdural haematoma (ASDH) is associated with severe traumatic brain injury and poor outcomes. Although guidelines exist for the decompression of ASDH, the question of adequate decompression remains unanswered. The authors examined the relationship of intracranial pressure (ICP) on closure with outcomes to determine its utility in the determination of adequate ASDH decompression.

METHODS

A multicentre retrospective review of 105 consecutive patients with ASDH who underwent decompressive surgery was performed. Receiver operating characteristic (ROC) analysis with internal validation was performed to determine an ICP threshold for the division of patients into the inadequate and good ICP groups. Multivariable analyses were performed for both inpatient and long-term outcomes.

RESULTS

An ICP threshold of 10 mmHg was identified with a 91.5% specificity, 45.7% sensitivity, and a positive and negative predictive value of 80.8% and 68.4%. There were 26 patients (24.8%) and 79 patients (75.2%) in the inadequate and good ICP groups, respectively. After adjustment, the inadequate ICP group was associated with increased postoperative usage of mannitol (OR 14.2, p < 0.001) and barbiturates (OR 150, p = 0.001). Inadequate ICP was also associated with increased inpatient mortality (OR 24.9, p < 0.001), and a lower rate of favourable MRS at 1 year (OR 0.08, p = 0.008). The complication rate was similar amongst the groups.

CONCLUSIONS

Closure ICP is a novel, objective, and actionable intraoperative biomarker that correlates with inpatient and long-term outcomes in ASDH. Various surgical manoeuvres can be undertaken to achieve this target safely. Large-scale prospective studies should be performed to validate this ICP threshold.

Factors Associated with Acute Obstructive Hydrocephalus After Retrosigmoid Approach for Extra-Axial Cerebellopontine Angle Tumors

BACKGROUND

This study aimed to identify the risk factors for acute obstructive hydrocephalus (AOHCP) after extra-axial cerebellopontine angle (CPA) tumor surgery using the retrosigmoid (RS) approach.

METHODS

This retrospective study assessed 154 patients (100 vestibular schwannomas, 34 CPA meningiomas [MNGs], 9 trigeminal schwannomas, and 11 petroclival MNGs) who underwent surgical resection using the RS approach by a single surgeon between August 2010 and September 2019. AOHCP was defined as postoperative ventricular enlargement due to cerebrospinal fluid flow obstruction caused by surgery-related cerebellar injury within 1 week. The radiological characteristics of the tumors were classified, and the surgical outcomes were reviewed. We analyzed the impact of different factors on the development of AOHCP after surgery.

RESULTS

AOHCP developed in 17 (11%) patients, all of whom were treated with external ventricular drain insertion. Multivariate analysis showed that CPA MNGs (odds ratio [OR], 37.98), grade of tumor extension beyond the petroclival junction (grade 1: OR, 16.42; grade 2: OR, 17.47), major fourth ventricle compression (OR, 17.77), and surgery-related hemorrhage (OR, 7.64) were associated with AOHCP. Surgery-related hemorrhage was observed in 17 (11%) patients. 9 (6%) patients underwent ventriculoperitoneal shunt surgery because of persistent HCP.

CONCLUSIONS

An increased risk of AOHCP after the RS approach was observed in patients with extra-axial CPA tumors with clival extension and major fourth ventricle compression. Compulsive and meticulous hemostasis must be achieved because postoperative hemorrhage is associated with AOHCP.

Skin landmarks as ideal entry points for ventricular drainage, a radiological study

PURPOSE

Ventricular drainage remains a usual but challenging procedure for neurosurgical trainees. The objective of the study was to describe reliable skin landmarks for ideal entry points (IEPs) to catheterize brain ventricles via frontal and parieto-occipital approaches.

METHODS

We included 30 subjects who underwent brain MRI and simulated the ideal catheterization trajectories of lateral ventricles using anterior and posterior approaches and localized skin surface IEPs. The optimal frontal target was the interventricular foramen and that for the parieto-occipital approach was the atrium. We measured the distances between these IEPs and easily identifiable skin landmarks.

RESULTS

The frontal IEP was localized to 116.8 ± 9.3 mm behind the nasion on the sagittal plane and to 39.7 ± 4.9 mm lateral to the midline on the coronal plane. The ideal catheter length was estimated to be 68.4 ± 6.4 mm from the skin surface to the interventricular foramen. The parieto-occipital point was localized to 62.9 ± 7.4 mm above the ipsilateral tragus on the coronal plane and to 53.1 ± 9.1 mm behind the tragus on the axial plane. The ideal catheter length was estimated to be 48.3 ± 9.6 mm.

CONCLUSION

The IEP for the frontal approach was localized to 11 cm above the nasion and 4 cm lateral to the midline. The IEP for the parieto-occipital approach was 5.5 cm behind and 6 cm above the tragus. These measurements lightly differ from the classical descriptions of Kocher's point and Keen's point and seem relevant to neurosurgical practice while using an orthogonal insertion.

Intracranial pressure monitoring during stereoelectroencephalography implantation: a technical note

Stereoelectroencephalography (SEEG) has become increasingly employed as a critical component of epilepsy workups for patients with drug-resistant epilepsy when information from noninvasive studies is not conclusive and sufficient to guide epilepsy surgery. Although exceedingly rare, clinically significant hemorrhagic complications can be caused during SEEG implantation procedures. Intracranial hemorrhage (ICH) can be difficult to recognize due to the minimally invasive nature of SEEG. The authors describe their technique using a commercially available intraparenchymal intracranial pressure (ICP) monitor as a method for early intraoperative detection of ICH during SEEG implantation. Between May 2019 and July 2021, 18 pediatric patients underwent SEEG implantation at a single, freestanding children's hospital with the use of an ICP monitor during the procedure. No patients experienced complications resulting from this technique. The authors have relayed their rationale for ICP monitor use during SEEG, the technical considerations, and the safety profile. In addition, they have reported an illustrative case in which the ICP monitor proved crucial in early detection of ICH during SEEG implantation.

A Morphometric Analysis of Commonly Used Craniometric Approaches for Freehand Ventriculoperitoneal Shunting

BACKGROUND

Ventricular catheter tip position is a predictor for ventriculoperitoneal shunt survival. Cannulation is often performed freehand, but there is limited consensus on the best craniometric approach.

OBJECTIVE

To determine the accuracy of localizing craniometric entry sites and to identify which is associated with optimal catheter placement.

METHODS

This is a retrospective analysis of adult patients who underwent ventriculoperitoneal shunting. The approaches were categorized as Kocher's, Keen's, Frazier's and Dandy's points as well as the parieto-occipital point. An accurately sited burr hole was within 10 mm from standard descriptions. Optimal catheter tip position was defined as within the ipsilateral frontal horn.

RESULTS

A total of 110 patients were reviewed, and 58% (65/110) of burr holes were accurately sited. Keen's point was the most correctly identified (65%, 11/17), followed by Kocher's point (65%, 37/57) and Frazier's point (60%, 3/5). Predictors for accurate localization were Keen's point (odds ratio 0.3; 95% CI: 01-0.9) and right-sided access (odds ratio 0.4; 95% CI: 0.1-0.9). Sixty-three percent (69/110) of catheters were optimally placed with Keen's point (adjusted odds ratio 0.04; 95% CI: 0.01-0.67), being the only independent factor. Thirteen patients (12%) required shunt revision at a mean duration of 10 ± 25 mo. Suboptimal catheter tip position was the only independent determinant for revision (adjusted odds ratio 0.11; 95% CI: 0.01-0.98).

CONCLUSION

This is the first study to compare the accuracy of freehand ventricular cannulation of standard craniometric entry sites for adult patients. Keen's point was the most accurately sited and was a predictor for optimal catheter position. Catheter tip location, not the entry site, predicted shunt survival.

Analysis of a Novel Entry Point for Freehand Ventriculostomy Using Computerized Tomography Scans

Background

External ventricular drain (EVD) placement is one of the most common procedures in neurosurgery. Neurosurgeons generally prefer to access the ventricles via Kocher’s point since it is the most common point of entry to this area; however, this point is used to describe different anatomic landmarks and is not well-defined.

Objective

The present study aims to describe and provide an anatomical assessment of a novel ventriculostomy access point developed by the authors using computerized tomography (CT) scans performed on 100 patients.

Materials and methods

Data were collected from 100 randomly selected patients with normal ventricular anatomy found on their 1.0 mm-slice CT scans performed at the Burdenko Neurosurgical Center from March 2019 to June 2021. The CT inclusion criteria were: CT slices < or = to 1 mm and absence of brain herniation. Patients with brain mass lesions, severe brain edema, and pneumocephalus were excluded. Age, gender, and ventricular size were not exclusion criteria.

Results

The mean patient age was 43.58 years (range 4-73), with 50 men and 50 women. The mean Evan’s index was 25.7 % (SD=4.38 %, range 10.2-41.0 %). No differences were found between the angles of EVD placement on either side (89.50±1.22 degrees on the right and 89.60±1.14 degrees on the left). Hence, nearly all EVD cases had been placed perpendicularly to the skull surface at a pinpoint location.

Conclusion

The proposed point of successful ventriculostomy placement in this study was 3 cm from the bregma along the coronal suture. The angle of EVD placement was approximately 90 degrees in almost all patients and was independent of the patient’s age and the side of the head that was entered. Little correlation was found between the value of the entry angle and Evan’s index. The point is simply identifiable, and its entry is easily accessible in practice.

Torkildsen's Ventriculocisternostomy First Applications: The Anthropological Evidence of a Young Slavic Soldier Who Died in the Torre Tresca Concentration Camp (Bari, Italy) in 1946

Human skeletal remains are considered as real biological archives of each subject's life. Generally, traumas, wounds, surgical interventions, and many human pathologies suffered in life leave identifiable marks on the skeleton, and their correct interpretation is possible only through a meticulous anthropological investigation of skeletal remains. The study here presented concerns the analysis of a young Slavic soldier's skeleton who died, after his imprisonment, in the concentration camp of Torre Tresca (Bari, Italy), during the Second World War (1946). In particular, the skull exhibited signs of surgical activity on the posterior cranial fossa and the parieto-occipital bones. They could be attributed to surgical procedures performed at different times, showing various degrees of bone edge remodeling. Overall, it was possible to correlate the surgical outcomes highlighted on the skull to the Torkildsen's ventriculocisternostomy (VCS), the first clinically successful shunt for cerebrospinal fluid (CSF) diversion in hydrocephalus, which gained widespread use in the 1940s. For this reason, the skeleton we examined represents a rare, precious, and historical testimony of an emerging and revolutionary neurosurgical technique, which differed from other operations for treating hydrocephalus before the Second World War and was internationally recognized as an efficient procedure before the introduction of extracranial shunts.

Skin landmarks to main cerebral structures: how to identify the main cerebral sulci? An anatomical study

PURPOSE

Neuronavigation is used in neurosurgical practice to locate the cortical structures. If this tool is unavailable, basic anatomical knowledge should be used. Craniometry has been rarely detailed in recent literature, systematically using bony landmarks. The aim of this study is to describe skin landmarks for neurosurgical practice.

METHODS

Dissection of 10 hemispheres with insertion of radio-opaque markers within the limits of lateral sulcus, central and pre-central sulci, and preoccipital notch. Computed tomography was performed in all cases and multiplanar reconstructions were performed. Maximal intensity projection (MIP) fusion images were used for measurements between known skin landmarks and sulci of interests.

RESULTS

The Anterior Sylvian Point is measured 31.8 ± 2.8 mm behind the orbital wall, 36.9 ± 3 mm above the zygomatic arch. The horizontal part of the lateral sulcus is measured 59 ± 6 mm above the tragus. The Superior Rolandic Point is measured 190.7 ± 4.5 mm behind the nasion. The Pre-occipital Notch is measured 37.0 ± 6.9 mm above the tragus and 67.1 ± 6.4 mm behind. The Ideal Entry Points (IEP) for ventricular punctures are measured 120.2 ± 7 mm behind the nasion and 33.8 ± 3 mm laterally for the frontal IEP, and 61.3 mm ± 2.5 mm above and 64.7 ± 6.8 mm behind the tragus for the parieto-occipital IEP.

CONCLUSION

In this study, we described simple skin landmarks for lateral sulcus, central sulcus, preoccipital notch, and an IEP for ventricular drainage. Precise knowledge of brain sulcal anatomy will guide patient's positioning, skin incision, and craniotomies; and permits checking of imaging data provided by neuronavigation systems.

Pre-operative imaging and post-operative appearance of standard paediatric neurosurgical approaches: a training guide for neuroradiologists

A short-cut narrative review was conducted according to the SANRA guidelines to identify studies describing normal and abnormal postoperative radiological features of the most common paediatric neurosurgical procedures. Rather than focusing on the original pathology addressed by neurosurgical means, this review explored three main areas of operative neurosurgery: ventricular access, supratentorial & infratentorial craniotomies, and posterior fossa/craniocervical junction decompression. A total of twenty-three landmark papers were included for review based on their relevance to address the research question and serve as a practical guide for paediatric neuroradiology trainees and fellows. Accurate in text referencing of the ClinicalTrials.gov identifier, and weblink, has also been provided for all trials discussed in the results section. All the above is complemented by relevant iconography meant to describe a wide range of postoperative changes and early complications. Finally, the review is enriched by a discussion touching upon haemostatic agents, intentionally retained foreign bodies and the future of machine learning for neuroradiology reporting. Overall, the information presented in a systematic fashion will not only help trainees and fellows to deepen these topics and expand their knowledge in preparation for written and oral boards, but will also represent a useful resource for everyone including trained neuroradiologists and neurosurgeons themselves.

Common Trajectories for Freehand Frontal Ventriculostomy: A Systematic Review

BACKGROUND

Freehand ventriculostomy is one of the most commonly performed neurosurgical procedures. While a variety of approaches have been described, frontal via Kocher's point is the most common. Multiple trajectories have been described, but no consensus exists as to the most efficacious. Our objective was to assess the literature regarding trajectories for frontal ventriculostomy and their associated success rates and complications.

METHODS

We performed a systematic review of the literature, querying the PubMed/MEDLINE database with the search term "(EVD OR extra-ventricular drain OR ventriculostomy OR external ventricular drain) AND (hand OR freehand OR bedside)" and reported the characteristics and findings of both simulation and clinical studies according to trajectory and catheter position. Final catheter tip position was graded on the Kakarla scale.

RESULTS

A total of 198 abstracts were screened; 40 full papers were assessed. Sixteen were included, 11 of which were clinical studies and 5 of which were simulation studies. Six studies coronally targeted the ipsilateral medial epicanthus (IMC), 4 utilized an orthogonal trajectory (P), and 1 targeted the naison (N). Ideal placement (Kakarla grade 1) was achieved in 954 of 1391 (68.58%) procedures when the IMC was targeted versus 243 of 354 (70.43%) when P was targeted. Potentially harmful (Kakarla grade 3) placement was observed in 142 of 1391 (10.21%) procedures when the IMC was targeted and 20 of 345 (5.80%) when P was targeted. All 5 simulation studies found the IMC target to be inferior.

CONCLUSIONS

The IMC is the most prevalent trajectory for frontal ventriculostomy but no target is demonstrably superior. More robust clinical research is required to determine the optimal trajectory.

The Longissimus Capitis Insertion as a Superficial Landmark for the Sigmoid Sinus: An Anatomical Study

Objective Many external anatomical landmarks have been used for approximating deeper, intracranial structures. Herein, we evaluate the attachment of the longissimus capitis (LC) on the mastoid process as a landmark for the underlying sigmoid sinus.

Methods Adult cadavers underwent dissection of the posterior occiput with special attention to the attachment of the LC muscle. Once the periphery of the muscle's tendon of attachment was determined, a burr hole was made in this area and evaluated internally for its relationship to the sigmoid sinus.

Results From an intracranial view, burr holes on all sides were over the sigmoid sinus and just slightly lateral to the center of the sinus. The distance from the midline to the medial border of the insertion of the LC had a mean of 63.0 ± 7.2 mm. The width of the tendon of insertion of the LC on the mastoid process had a mean of 17.6 ± 5.7 mm. The length of the tendon insertion of the LC had a mean of 14.7 ± 4.7 mm. The distance from the inferior border of the insertion of the LC to the tip of the mastoid process had a mean of 6.2 ± 4.5 mm.

Conclusion To our knowledge, use of the attachment site of the LC on the mastoid process as an external landmark for the underlying sigmoid sinus has not previously been reported. Based on our cadaveric findings, the sigmoid sinus is centered under the attachment of the LC regardless of the width of its tendon.

Compared with conventional procedures, an intraoperative navigation system for ventriculoperitoneal shunting via the occipital horn improves outcomes in patients with hydrocephalus

BACKGROUND

Ventriculoperitoneal shunting (VPS) is a common neurosurgical procedure used to treat hydrocephalus. Although the use of a navigation system in VPS achieves superior results compared with conventional surgery, the relationships among clinical symptoms, ventricular catheter placement, catheter obstruction, and the postoperative Evans index have not been clearly reported.

METHODS

We performed a retrospective study of 40 patients with VPS (the navigation surgery group) and 31 patients with VPS (the conventional surgery group). Clinical data, follow-up times, catheterization accuracy, postoperative outcomes, cumulative survival times, and correlations between catheter placement and obstruction, symptom grade and the postoperative Evans index were analyzed.

RESULTS

Thirty-seven patients experienced optimal ventricular catheter placement (grade 1), three experienced suboptimal placements (grade 2), and none experienced poor ventricular catheter placement (grade 3) in the navigation surgery group. Greater improvement in postoperative symptoms (p < 0.001), including less catheter readjustment (p < 0.001), was observed in the navigation surgery group. A Kaplan-Meier analysis showed that the cumulative catheter obstruction-free survival time was longer in the navigation surgery group (p = 0.016). Moreover, catheter placement was significantly correlated with catheter obstruction (p < 0.001). Additionally, catheter obstruction was significantly correlated with the symptom grade (p < 0.001) and postoperative Evans index (p = 0.002).

CONCLUSION

VPS for hydrocephalus via the occipital horn with a navigation system is superior to the conventional surgical procedure in terms of clinical outcomes, the precision of ventricular catheterization, and the occurrence of complications. Catheter obstruction-free survival times were longer in the navigation surgery group and catheter placement was significantly correlated with catheter obstruction.

Immersive Surgical Anatomy of the Craniometric Points

Craniometric points (CPs) have been used in neurosciences since the 1800s. Localization of the CPs allows for the identification of crucial intracranial structures. Despite the contribution of advanced technology to surgery, the knowledge of these points remains crucial for surgical planning and intraoperative orientation. The understanding of these crucial points can be facilitated with the use of three-dimensional technology combined with anatomical dissections. The present study is part of a stereoscopic collection of volumetric models (VMs) obtained from cadaveric dissections that depict the relevant anatomy of the CPs. Five embalmed heads and two dry skulls have been used to depict these points. After the anatomical dissection, stereoscopic images and VMs were generated to show the correlation between external and internal landmarks. The CPs identified were divided into sutures, suture junctions, prominences and depressions, and cortical surface landmarks. The VMs represent an interactive way to define these points easily and their correlation with different intracranial structures (vascular structure, ventricle cavity, and Brodmann’s areas).

The Iatrogenic Development of an Anterior Cerebral Artery Pseudoaneurysm during Lamina Terminalis Fenestration-Genesis, Diagnosis and Therapy: Lessons Learned

Intracranial pseudoaneurysms (PSA) are scarcely presented in the literature. We describe the case of an intracranial PSA on the right anterior cerebral artery, which developed during the complicated surgical treatment of a ruptured right middle cerebral aneurysm. The pseudoaneurysm grew over time and was co-incidentally diagnosed 3 months after the original surgery. The PSA was successfully treated by coiling. In cases of vascular injuries during complicated brain surgery, the timely and careful radiological diagnosis of such a lesion is necessary to allow its fast and proper treatment and thus prevent the patient from potential risks.

Thiel's embalming method with additional intra-cerebral ventricular formalin injection (TEIF) for cadaver training of head and brain surgery

Thiel’s embalming method provides natural coloration, flexibility, and tissue plasticity, and is used widely to prepare specimens for cadaver surgical training. However, this method causes brain softening, thereby restricting the cadaver surgical training of intra-cranial procedures. In this study, three cadavers were embalmed using formalin fixation, Thiel’s embalming method, and Thiel’s embalming method with additional intra-cerebral ventricular formalin injection, respectively. We also established rat models of the three embalming methods to develop and determine the best method for retaining adequate brain elasticity. The intra-ventricular formalin injection in the cadaver was performed through the Kocher’s point, as in the classical external ventricular drain procedure. Both, the cadaver brains and rat models yielded consistent shear wave measurements and brain surface stiffness data. Notably, the Thiel’s embalming method with additional intra-cerebral ventricular formalin injection yielded suitable elasticity for brain cadaver surgical training in terms of brain mobilization and surgical field deployment, and also discharged formaldehyde in undetectable quantities. To our knowledge, this is the first report in which a fixed quality, namely, brain elasticity for the performance of head and brain cadaver surgical training, has been evaluated in a cadaver subjected to the Thiel’s embalming method with immersion fixation in the cerebrospinal fluid space. We conclude that the Thiel’s embalming method with additional intra-cerebral ventricular formalin injection can maintain the brain elasticity, and may therefore improve the quality of head and brain cadaver surgical training safely and easily.