Common Trajectories for Freehand Frontal Ventriculostomy: A Systematic Review

Novel freehand frontal ventriculostomy in the supraorbital keyhole approach: technical note

BACKGROUND AND OBJECTIVES

The narrow surgical passage provided by the supraorbital keyhole craniotomy restricts the instrument's maneuverability and presents a number of technical challenges. Inadequate brain relaxation may eventually result in unavoidable brain retraction and neurological impairments. The article aims to provide a novel intraoperative ventriculostomy to assist in overcoming the barrier of a narrow surgical corridor and assess its feasibility and safety compared to other techniques.

METHODS

The craniometric point was planned on one normal computed tomography (CT) brain. The coordinates were verified on 43 magnetic resonance imaging (MRI) brain images uploaded on the neuronavigation system (StealthStation S8 version 1.0; Medtronic, Louisville, USA). The ventriculostomy point was 3 cm superior to glabella, 2 cm lateral to midline, 6 cm deep to the brain surface in the perpendicular direction, and parallel to the floor of the anterior cranial fossa. Subsequently, the abovementioned radiologically calculated ventriculostomy trajectory was confirmed on 32 consecutive patients (without neuronavigation) of suprasellar mass undergoing supraorbital craniotomy between February 2022 and April 2023. The technical issues, feasibility, and outcomes were assessed.

RESULTS

Out of 32 patients, in 29 patients, ventricular hit was attained in a single attempt, and the rest 3 patients needed two attempts. The intraoperative ventricular hit rate was 100% with 90.6% success in a single attempt. No ventriculostomy-related complications occurred. Compared to ELD (external lumbar drainage), performing an intraoperative ventriculostomy had no discernible difference in the perception of the brain retraction force. Intraoperative ventriculostomy fully eliminated the low back pain or radiculopathy that patients with ELD rarely have even after drain removal.

CONCLUSION

The novel intraoperative frontal ventriculostomy is a safe trajectory and is a valid alternative to Menovsky's ventriculostomy or external lumbar drainage. The authors recommend this technique be generally utilized in supraorbital keyhole approaches to optimize brain relaxation and minimize secondary adverse events.

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.

Multimodal Haptic Simulation for Ventriculostomy Training. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083370 DOI: 10.1109/embc40787.2023.10340701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Freehand ventriculostomy is a frequent surgical procedure and is among the first ones that junior neurosurgery residents learn. Although training simulators exist, none has been adopted in the clinical routine to train junior residents. This paper focuses on a novel multimodal haptic training simulator that will lift the limitations of current simulators. We thus propose an architecture that integrates (1) visual feedback through augmented MRIs, and (2) a physical mock-up of the patient's skull to (3) active haptic feedback.

Simulation Method for the Physical Deformation of a Three-Dimensional Soft Body in Augmented Reality-Based External Ventricular Drainage

OBJECTIVES

Intraoperative navigation reduces the risk of major complications and increases the likelihood of optimal surgical outcomes. This paper presents an augmented reality (AR)-based simulation technique for ventriculostomy that visualizes brain deformations caused by the movements of a surgical instrument in a three-dimensional brain model. This is achieved by utilizing a position-based dynamics (PBD) physical deformation method on a preoperative brain image.

METHODS

An infrared camera-based AR surgical environment aligns the real-world space with a virtual space and tracks the surgical instruments. For a realistic representation and reduced simulation computation load, a hybrid geometric model is employed, which combines a high-resolution mesh model and a multiresolution tetrahedron model. Collision handling is executed when a collision between the brain and surgical instrument is detected. Constraints are used to preserve the properties of the soft body and ensure stable deformation.

RESULTS

The experiment was conducted once in a phantom environment and once in an actual surgical environment. The tasks of inserting the surgical instrument into the ventricle using only the navigation information presented through the smart glasses and verifying the drainage of cerebrospinal fluid were evaluated. These tasks were successfully completed, as indicated by the drainage, and the deformation simulation speed averaged 18.78 fps.

CONCLUSIONS

This experiment confirmed that the AR-based method for external ventricular drain surgery was beneficial to clinicians.

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.

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.

Multimodal Simulation of a Novel Device for a Safe and Effective External Ventricular Drain Placement

Background

External ventricular drain (EVD) placement is mandatory for several pathologies. The misplacement rate of the EVD varies widely in literature, ranging from 12.3 to 60%. The purpose of this simulation study is to provide preliminary data about the possibility of increasing the safety of one of the most common life-saving procedures in neurosurgery by testing a new device for EVD placement.

Methods

We used a novel guide for positioning the ventricular catheter (patent RM2014A000376). The trajectory was assessed using 25 anonymized head CT scans. The data sets were used to conduct three-dimensional computer-based and combined navigation and augmented reality-based simulations using plaster models. The data set inclusion criteria were volumetric head CT scan, without midline shift, of patients older than 18. Evans' index was used to quantify the ventricle's size. We excluded patients with slit ventricles, midline shift, skull fractures, or complex skull malformations. The proximal end of the device was tested on the cadaver.

Results

The cadaveric tests proved that a surgeon could use the device without any external help. The multimodal simulation showed Kakarla grade 1 in all cases but one (grade 2) on both sides, after right and left EVD placement. The mean Evans' index was 0.28. The geometric principles that explain the device's efficacy can be summarized by studying the properties of circumference and chord. The contact occurs, for each section considered, at the extreme points of the chord. Its axis, perpendicular to the plane tangent to the spherical surface at the entry point, corresponds to the direction of entry of the catheter guided by the instrument.

Conclusion

According to our multimodal simulation on cadavers, 3D computer-based simulation, 3D plaster modeling, 3D neuronavigation, and augmented reality, the device promises to offer safer and effective EVD placement. Further validation in future clinical studies is recommended.