scholarly journals sEVD—smartphone-navigated placement of external ventricular drains

2019 ◽  
Vol 162 (3) ◽  
pp. 513-521
Author(s):  
Christian V. Eisenring ◽  
Felice Burn ◽  
Michelle Baumann ◽  
Lennart H. Stieglitz ◽  
Ralf A. Kockro ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Standard Procedure ◽  
External Ventricular Drain ◽  
Head Model ◽  
Anatomical Landmarks ◽  
Frontal Horn ◽  
Freehand Technique ◽  
Multifunctional Device ◽  
The Mean ◽  
Ct Data

Abstract Background Currently, the trajectory for insertion of an external ventricular drain (EVD) is mainly determined using anatomical landmarks. However, non-assisted implantations frequently require multiple attempts and are associated with EVD malpositioning and complications. The authors evaluated the feasibility and accuracy of a novel smartphone-guided, angle-adjusted technique for assisted implantations of an EVD (sEVD) in both a human artificial head model and a cadaveric head. Methods After computed tomography (CT), optimal insertion angles and lengths of intracranial trajectories of the EVDs were determined. A smartphone was calibrated to the mid-cranial sagittal line. Twenty EVDs were placed using both the premeasured data and smartphone-adjusted insertion angles, targeting the center of the ipsilateral ventricular frontal horn. The EVD positions were verified with post-interventional CT. Results All 20 sEVDs (head model, 8/20; cadaveric head, 12/20) showed accurate placement in the ipsilateral ventricle. The sEVD tip locations showed a mean target deviation of 1.73° corresponding to 12 mm in the plastic head model, and 3.45° corresponding to 33 mm in the cadaveric head. The mean duration of preoperative measurements on CT data was 3 min, whereas sterile packing, smartphone calibration, drilling, and implantation required 9 min on average. Conclusions By implementation of an innovative navigation technique, a conventional smartphone was used as a protractor for the insertion of EVDs. Our ex vivo data suggest that smartphone-guided EVD placement offers a precise, rapidly applicable, and patient-individualized freehand technique based on a standard procedure with a simple, cheap, and widely available multifunctional device.

scholarly journals App-assisted external ventricular drain insertion

2016 ◽  
Vol 125 (3) ◽  
pp. 754-758 ◽  
Author(s):  
Behzad Eftekhar
Keyword(s):  
Augmented Reality ◽  
Ex Vivo ◽  
External Ventricular Drain ◽  
Ease Of Use ◽  
Anatomical Landmarks ◽  
Frontal Horn ◽  
Neurosurgical Planning ◽  
Freehand Technique ◽  
Individual Variations ◽  
Tailored Approach

The freehand technique for insertion of an external ventricular drain (EVD) is based on fixed anatomical landmarks and does not take individual variations into consideration. A patient-tailored approach based on augmented-reality techniques using devices such as smartphones can address this shortcoming. The Sina neurosurgical assist (Sina) is an Android mobile device application (app) that was designed and developed to be used as a simple intraoperative neurosurgical planning aid. It overlaps the patient's images from previously performed CT or MRI studies on the image seen through the device camera. The device is held by an assistant who aligns the images and provides information about the relative position of the target and EVD to the surgeon who is performing EVD insertion. This app can be used to provide guidance and continuous monitoring during EVD placement. The author describes the technique of Sina-assisted EVD insertion into the frontal horn of the lateral ventricle and reports on its clinical application in 5 cases as well as the results of ex vivo studies of ease of use and precision. The technique has potential for further development and use with other augmented-reality devices.

Placement of External Ventricular Drain: Comparison of Two Methods

2019 ◽  
Vol 80 (02) ◽  
pp. 116-121 ◽  
Author(s):  
Frank Schwarm ◽  
Marco Stein ◽  
Eberhard Uhl ◽  
Marcus Reinges ◽  
Michael Bender
Keyword(s):  
Standard Procedure ◽  
External Ventricular Drain ◽  
Ventricular Catheter ◽  
Chronic Hydrocephalus ◽  
Emergency Procedure ◽  
Point Scale ◽  
Correct Position ◽  
Freehand Technique ◽  
Significant Difference ◽  
Computed Tomography Scans

Background Insertion of a frontal external ventricular drain (EVD) is a common emergency procedure in neurosurgery. Malpositioning of the EVD and/or triggering a new intracerebral or intraventricular hemorrhage (nICVH) are typical complications. The standard procedure (SP) uses a tape measure to identify the Kocher's point for placement of a frontal burr hole. A faster alternative to determine the correct position is the freehand technique (FHT). This study compared both techniques with regard to the correct positioning of the EVD tip and the induction catheter-induced nICVH. Methods We performed a retrospective analysis of patients who required an EVD for acute or chronic hydrocephalus between January 2013 and March 2014. The study consisted of two groups. In the first group, EVDs were placed with the FHT. In the second group the SP was used. Postoperative computed tomography scans were analyzed regarding correct positioning of the ventricular catheter, malpositioning of the tip of the EVD using a 4-point-scale, and evidence for catheter-induced nICVH. Results A total of 95 patients could be included. The FHT was performed in 43 cases and the SP in 52 cases. No significant differences between the two groups were found regarding the correct position of the EVD tip (p = 0.38) and nICVH (p = 0.12). There was no significant difference in malpositioning of the EVD tip between the groups (p = 0.34). Conclusion Our results show no significant differences between the two methods with regard to correct position, malpositioning, and nICVH. Thus we conclude that the FHT is a fast, safe, and effective alternative to the SP.

Freehand Insertion of External Ventricular Drainage Catheter–Evaluation of Accuracy in a Single Centre

Neurosurgery ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. E271-E271 ◽  
Author(s):  
Keng Siang Lee ◽  
Tseng Tsai Yeo ◽  
Ning Chou ◽  
Prof Sein Lwin ◽  
Kejia Teo ◽  
...  
Keyword(s):  
External Ventricular Drain ◽  
External Ventricular Drainage ◽  
Burr Hole ◽  
Anatomical Landmarks ◽  
Midline Shift ◽  
Frontal Horn ◽  
Significant Difference ◽  
Catheter Tip ◽  
Procedural Complications ◽  
Interhemispheric Fissure

Abstract INTRODUCTION External ventricular drain (EVD) placement is the gold standard for managing acute hydrocephalus. Freehand EVD, using surface anatomical landmarks is performed for ventricular cannulation due to its simplicity and efficiency. This study evaluates accuracy and reason(s) for misplacements as few studies have analyzed the accuracy of freehand EVD insertion. METHODS Preoperative and postoperative computed tomography (CT) scans of patients who underwent EVD insertion in 2014 were retrospectively reviewed. Diagnosis, Evan's ratio, midline shift, position of burr hole, length of the catheter and procedural complications were tabulated. The procedures were classified as satisfactory (catheter tip in the frontal horn ipsilateral lateral ventricle) and unsatisfactory. Unsatisfactory cases were further analyzed in relation to position of burr hole from midline and length of the catheter. RESULTS A total of 77 EVD placements in 70 patients were evaluated. Mean age of the patients was 57.5 yr. About 83.1% were satisfactory placements and 11.7% were unsatisfactory in the contralateral ventricle, corpus callosum and interhemispheric fissure. About 5.2% were in extra ventricular locations. About 2.6% EVD placements were complicated by hemorrhage and 1 catheter was reinserted. Suboptimal placements were significantly associated with longer intracranial catheter length. The mean length was 66.54 ± 10.1 mm in unsatisfactory placements compared to 58.32 ± 4.85 mm in satisfactory placements. Between the 2 groups, no significant difference was observed in Evan's ratio, midline shift, surgeon's experience, distance of burr hole from midline and coronal suture. CONCLUSION Freehand EVD insertion is safe and accurate. In small number of cases, unsatisfactory placement is related to longer catheter length.

Validation of a freehand technique for cortical bone trajectory screws in the lumbar spine

2019 ◽  
Vol 31 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Zachary Tan ◽  
Stewart McLachlin ◽  
Cari Whyne ◽  
Joel Finkelstein
Keyword(s):  
Lumbar Spine ◽  
Cortical Bone ◽  
Pedicle Screw ◽  
Ex Vivo ◽  
Screw Placement ◽  
Anatomical Landmarks ◽  
Cortical Bone Trajectory ◽  
Screw Insertion ◽  
Freehand Technique ◽  
Ex Vivo Study

OBJECTIVEThe cortical bone trajectory (CBT) technique for pedicle screw placement has gained popularity among spinal surgeons. It has been shown biomechanically to provide better fixation and improved pullout strength compared to a traditional pedicle screw trajectory. The CBT technique also allows for a less invasive approach for fusion and may have lower incidence of adjacent-level disease. A limitation of the current CBT technique is a lack of readily identifiable and reproducible visual landmarks to guide freehand CBT screw placement in comparison to the well-defined identifiable landmarks for traditional pedicle screw insertion. The goal of this study was to validate a safe and intuitive freehand technique for placement of CBT screws based on optimization of virtual CBT screw placement using anatomical landmarks in the lumbar spine. The authors hypothesized that virtual identification of anatomical landmarks on 3D models of the lumbar spine generated from CT scans would translate to a safe intraoperative freehand technique.METHODSCustomized, open-source medical imaging and visualization software (3D Slicer) was used in this study to develop a workflow for virtual simulation of lumbar CBT screw insertion. First, in an ex vivo study, 20 anonymous CT image series of normal and degenerative lumbar spines and virtual screw insertion were conducted to place CBT screws bilaterally in the L1–5 vertebrae for each image volume. The optimal safe CBT trajectory was created by maximizing both the screw length and the cortical bone contact with the screw. Easily identifiable anatomical surface landmarks for the start point and trajectory that best allowed the reproducible idealized screw position were determined. An in vivo validation of the determined landmarks from the ex vivo study was then performed in 10 patients. Placement of virtual “test” cortical bone trajectory screws was simulated with the surgeon blinded to the real-time image-guided navigation, and the placement was evaluated. The surgeon then placed the definitive screw using image guidance.RESULTSFrom the ex vivo study, the optimized technique and landmarks were similar in the L1–4 vertebrae, whereas the L5 optimized technique was distinct. The in vivo validation yielded ideal, safe, and unsafe screws in 62%, 16%, and 22% of cases, respectively. A common reason for the nonidealized trajectories was the obscuration of patient anatomy secondary to severe degenerative changes.CONCLUSIONSCBT screws were placed ideally or safely 78% of the time in a virtual simulation model. A 22% rate of unsafe freehand trajectories suggests that the CBT technique requires use of image-guided navigation or x-ray guidance and that reliable freehand CBT screw insertion based on anatomical landmarks is not reliably feasible in the lumbar spine.

scholarly journals Ex vivo evaluation of a multilayered sealant patch for watertight dural closure: cranial and spinal models

2021 ◽  
Vol 32 (8) ◽  
Author(s):  
A. Kinaci ◽  
S. van Thoor ◽  
S. Redegeld ◽  
M. Tooren ◽  
T. P. C. van Doormaal
Keyword(s):  
Ex Vivo ◽  
Resistance Test ◽  
Burst Pressure ◽  
Cerebrospinal Fluid Leakage ◽  
Computer Assisted ◽  
Dural Defect ◽  
Test Results ◽  
Physiological Conditions ◽  
Dural Attachment ◽  
The Mean

AbstractCerebrospinal fluid leakage is a frequent complication after cranial and spinal surgery. To prevent this complication and seal the dura watertight, we developed Liqoseal, a dural sealant patch comprising a watertight polyesterurethane layer and an adhesive layer consisting of poly(DL-lactide-co-ε-caprolactone) copolymer and multiarmed N-hydroxylsuccinimide functionalized polyethylene glycol. We compared acute burst pressure and resistance to physiological conditions for 72 h of Liqoseal, Adherus, Duraseal, Tachosil, and Tisseel using computer-assisted models and fresh porcine dura. The mean acute burst pressure of Liqoseal in the cranial model (145 ± 39 mmHg) was higher than that of Adherus (87 ± 47 mmHg), Duraseal (51 ± 42 mmHg) and Tachosil (71 ± 16 mmHg). Under physiological conditions, cranial model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment during 72 hours as opposed to 3 of 3 for Adherus and Duraseal and 0 of 3 for Tachosil. The mean burst pressure of Liqoseal in the spinal model (233 ± 81 mmHg) was higher than that of Tachosil (123 ± 63 mmHg) and Tisseel (23 ± 16 mmHg). Under physiological conditions, spinal model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment for 72 hours as opposed to 3 of 3 for Adherus and 0 of 3 for Duraseal and Tachosil. This novel study showed that Liqoseal is capable of achieving a strong watertight seal over a dural defect in ex vivo models.

scholarly journals Ex vivo accuracy of three electronic apex locators using different apical file sizes

2012 ◽  
Vol 23 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Bruno Carvalho de Vasconcelos ◽  
Leonardo de Alencar Matos ◽  
Elilton Cavalcante Pinheiro-Júnior ◽  
Antônio Sérgio Teixeira de Menezes ◽  
Nilton Vivacqua-Gomes
Keyword(s):  
Root Canal ◽  
Ex Vivo ◽  
Chi Square ◽  
Apical Constriction ◽  
Visual Measurement ◽  
Chi Square Test ◽  
The Mean

This study evaluated the accuracy of three electronic apex locators (Root ZX, Novapex, and Justy II) in root canal length determinations using different apical file sizes, considering the apical constriction (AC) and the major foramen (MF) as anatomic references. The diameter of the apical foramina of 40 single-rooted teeth was determined by direct visual measurement and the master apical file was established. Electronic measurements were then performed using 3 instruments: the selected master apical file (adjusted file), one size smaller (intermediate file), and two sizes smaller (misfit file). The distances from the tip of files fixed in the canals to the MF and to the AC were measured digitally. Precision at AC and at MF for the misfit, intermediate and adjusted apical files was as follows: 80%/88%/83% and 78%/83%/95% (Root ZX); 80%/85%/80% and 68%/73%/73% (Novapex); and 78%/80%/78% and 65%/78%/70% (Justy II). Considering the mean discrepancies, statistically significant differences were found only for the adjusted file at MF, with Root ZX presenting the best results at MF. The chi-square test showed significant differences between the acceptable measurements at AC and at MF for the Justy II and Novapex (± 0.5 mm) regardless of file adjustment. Under the conditions of the present study, all devices provided acceptable electronic measurements regardless of file adjustment, except for Root ZX which had its performance improved significantly when the precisely fit apical file was used. Justy II and Novapex provided electronic measurements nearest to the AC.

External Ventricular Drain Infection

2007 ◽  
Vol 107 (1) ◽  
pp. 248 ◽  
Author(s):  
George K. C. Wong ◽  
Wayne W. S. Poon
Keyword(s):  
Major Trauma ◽  
Independent Predictor ◽  
External Ventricular Drain ◽  
Significant Risk ◽  
Significant Risk Factor ◽  
External Ventricular Drainage ◽  
Infection Rates ◽  
The Mean ◽  
The Relationship ◽  
Shed Light

Object The authors explored the relationship among the duration of external ventricular drainage, revision of external ventricular drains (EVDs), and cerebrospinal fluid (CSF) infection to shed light on the practice of electively revising these drains. Methods In a retrospective study of 199 patients with 269 EVDs in the intensive care unit at a major trauma center in Australasia, the authors found 21 CSF infections. Acinetobacter accounted for 10 (48%) of these infections. Whereas the duration of drainage was not an independent predictor of infection, multiple insertions of EVDs was a significant risk factor. Second and third EVDs in previously uninfected patients were more likely to become infected than first EVDs. An EVD infection was initially identified a mean of 5.5 ±0.7 days postinsertion (standard error of the mean); these data—that is, the number of days—were normally distributed. Conclusions This pattern of infection is best explained by EVD-associated CSF infections being acquired by the introduction of bacteria on insertion of the drain rather than by subsequent retrograde colonization. Elective EVD revision would be expected to increase infection rates in light of these results, and thus the practice has been abandoned by the authors' institution.

185 Vascular Hitch Procedure for Accessory Lower Pole Vessels

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
O Fashina ◽  
A Rajimwale
Keyword(s):  
Hospital Stay ◽  
Standard Procedure ◽  
Royal Infirmary ◽  
Lower Pole ◽  
Pelvic Wall ◽  
Stable Renal Function ◽  
The Mean ◽  
Leicester Royal Infirmary ◽  
Functional Magnetic Resonance Urography

Abstract Introduction The gold standard procedure for pelvi-ureteric junction obstruction has been the Anderson-Hynes dismembered pyeloplasty; involving the repositioning of the ureter and ureteropelvic anastomosis. However, the Hellstroem 'Vascular Hitch Procedure’ dictates the superior translocation of the accessory vessel and its fixation to the anterior pelvic wall. The latter has an estimated success rate >90%. Method During 2016-2020, at Leicester Royal Infirmary, 16 operations occurred on paediatric patients with pelvi-ureteric junction obstruction. The dismembered pyeloplasty was performed on 5 patients, 9 patients underwent the vascular hitch procedure, and 2 patients are currently awaiting the latter operation. All patients had a pre-operative functional magnetic resonance urography (fMRU) to identify and localise the accessory lower pole vessel. Results The mean hospital stay for the vascular hitch procedure was 1.5 days (range=1-2) in comparison to 4 days (range=3-5) for the dismembered pyeloplasty. The follow-up period ranged from 6 months to 3 years. Overall, it was noted that the patients were asymptomatic, had markedly reduced hydronephrosis on imaging as well as stable renal function noted on the MAG 3 renogram scan. Conclusions The laparoscopic vascular hitch procedure appears to be the superior operation for the management of pelvi-uteric junction obstruction as the patients had notably reduced hospital stay lengths.

Validation of Sonographic Fronto-Occipital Ratio Based on Anatomical Landmarks compared to MR/CT-Derived Indexes in Children with Chiari II and Ventriculomegaly

2021 ◽  
Author(s):  
Michele Retrouvey ◽  
Arastoo Vossough ◽  
Alireza Zandifar ◽  
Richard D. Bellah ◽  
Gregory G. Heuer ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Ventricular Volume ◽  
Coronal Plane ◽  
Anatomical Landmarks ◽  
Foramen Of Monro ◽  
Rater Reliability ◽  
Unique Challenge ◽  
Frontal Horn ◽  
Chiari Ii

Introduction: Ultrasound (US) based indexes such as fronto-occipital ratio (FOR) can be used to obtain an acceptable estimation of ventricular volume. Patients with colpocephaly present a unique challenge due to the shape of their ventricles. In the present study, we aim to evaluate the validity and reproducibility of modified US-FOR index in children with Chiari II-related ventriculomegaly. Methods: In this retrospective study, we evaluated Chiari II patients younger than one year who underwent head US and MR or CT scans for ventriculomegaly evaluation. MR/CT based FOR was measured in the axial plane by identifying the widest diameter of frontal horns, occipital horns, and the interparietal diameter (IPD). US based FOR (US-FOR) was measured using the largest diameter based on the following landmarks: frontal horn and IPD in the coronal plane at the level of the foramen of Monro, IPD just superior to the Sylvian fissures, and occipital horn posterior to the thalami and inferior to the superior margins of the thalami. Interclass correlation coefficients (ICC) were used to evaluate inter-rater reliability and Pearson correlation coefficients and Bland-Altman plots were applied to assess agreement between US and other two modalities. Results: Ninety paired US and MR/CT exams were assessed for agreement between US-FOR and MR/CT-FOR measurements. ICC showed an excellent inter-rater reliability for US-FOR (ICC=0.99, p<0.001) and MR/CT-FOR measurements (ICC=0.99, p<0.001). The mean (range) values based on US-FOR showed a slight overestimation in comparison to MR/CT-FOR [0.51 (0.36-0.68) vs 0.46 (0.34-0.64)]. Pearson correlation coefficient showed high cross-modality agreement for the FOR index (r=0.83, p<0.001). Bland-Altman plot showed excellent concordance between US-FOR and MR/CT-FOR with a bias of 0.05 (95% CI, -0.03-0.13) Conclusion: US-FOR in the coronal plane is a comparable tool for evaluating ventriculomegaly in Chiari II patients when compared with MR/CT-FOR, even in the context of colpocephaly.

scholarly journals Applied Force during Piston Prosthesis Placement in a 3D-Printed Model: Freehand vs Robot-Assisted Techniques

2018 ◽  
Vol 160 (2) ◽  
pp. 320-325 ◽  
Author(s):  
Christopher R. Razavi ◽  
Paul R. Wilkening ◽  
Rui Yin ◽  
Nicolas Lamaison ◽  
Russell H. Taylor ◽  
...  
Keyword(s):  
Middle Ear ◽  
Force Sensor ◽  
Neck Surgery ◽  
Maximum Force ◽  
Maximum Magnitude ◽  
Robot Assisted ◽  
Freehand Technique ◽  
Stapes Prosthesis ◽  
3D Printed ◽  
The Mean

Objectives To describe a 3D-printed middle ear model that quantifies the force applied to the modeled incus. To compare the forces applied during placement and crimping of a stapes prosthesis between the Robotic ENT Microsurgery System ( REMS) and the freehand technique in this model. Study Design Prospective feasibility study. Setting Robotics laboratory. Subjects and Methods A middle ear model was designed and 3D printed to facilitate placement and crimping of a piston prosthesis. The modeled incus was mounted to a 6–degree of freedom force sensor to measure forces/torques applied on the incus. Six participants—1 fellowship-trained neurotologist, 2 neurotology fellows, and 3 otolaryngology–head and neck surgery residents—placed and crimped a piston prosthesis in this model, 3 times freehand and 3 times REMS assisted. Maximum force applied to the incus was then calculated for prosthesis placement and crimping from force/torque sensor readings for each trial. Robotic and freehand outcomes were compared with a linear regression model. Results Mean maximum magnitude of force during prosthesis placement was 126.4 ± 73.6 mN and 105.0 ± 69.4 mN for the freehand and robotic techniques, respectively ( P = .404). For prosthesis crimping, the mean maximum magnitude of force was 469.3 ± 225.2 mN for the freehand technique and 272.7 ± 97.4 mN for the robotic technique ( P = .049). Conclusions Preliminary data demonstrate that REMS-assisted stapes prosthesis placement and crimping are feasible with a significant reduction in maximum force applied to the incus during crimping with the REMS in comparison with freehand.

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