Ventricular Catheter Placement Research Articles

The impact of real-time ultrasound guidance on ventricular catheter placement in cerebrospinal fluid shunts - a single-center study.

Misplacement of ventricular catheters during shunt surgery occurs in 40% of cases using a freehand technique and therefore represents a risk for early shunt failure. The goal of this retrospective, single-center study is to analyze the impact of real-time ultrasound guidance on ventricular catheter positioning and early outcome of shunt survival. We analyzed the charts and images of all patients who underwent shunt surgery from 09/2017 to 12/2022 and compared the position of the ventricular catheter using the freehand technique and real-time ultrasound guidance. Central catheter position was graded as grade I (optimal), II (contact with ventricle structures or contralateral), and III (misplacement). A ventricular catheter was placed in 244 patients using real-time US guidance and in 506 patients using a freehand technique. The mean age (53.4 and 53.6 years, respectively) and the preoperative frontal occipital horn ratio (FOHR; 0.47 versus 0.44) were almost equal in both groups. In the study group, grade I catheter position was achieved in 64% of cases, grade II in 34%, and grade III in 2%. The control group showed grade I position in 45%, grade II in 32%, and grade III in 23% of cases (p<0.05). An early central catheter failure rate was the highest in grade III (40.5%) compared to 4% in grade I. Our data demonstrate that real-time US guidance leads to a significant improvement in ventricular catheter placement. Consequently, early shunt revisions decrease significantly. Further prospective, randomized, and controlled studies comparing the standard method to real-time ultrasound catheter placement are required.

Are variations in ventricular catheter placement related to design of the catheter? A single-center cohort study.

The use of intracranial catheters is a common procedure used for neurosurgical patients with a variety of pathologies. Despite its frequency of use, shunt failure and revision have been reported to be a common problem. Given that depth of insertion can significantly affect the catheter tip position, a single institution retrospective chart review was performed to examine the accuracy of shunt and external ventricular drain (EVD) placement. Computed tomography (CT) images of the head following shunt or ventriculostomy insertion were analyzed to determine the delta between the final length of the intracranial catheter and the intended depth described in the operative notes. We found that there was a statistically significant difference in the accuracy of placement when comparing EVDs to shunts. The most used EVDs at our institution are marked with a solid black line in increments spaced 2 cm apart. The most used ventricular shunt catheter has a marking at 5 cm and 10 cm from the tip of the catheter. We believe that the visual confirmation that is afforded by metric unit markings on the EVD allows for better final placement of the catheter at the outer table of the calvarium. The addition of regular millimeter metric unit markings by the manufacturer is imperative in decreasing the chances of error in the insertion of ventricular catheters and preventing potential neurovascular injury to the surrounding structures.

A novel trans-occipital catheter placement guide for ventriculoperitoneal shunts.

We have designed a novel device that facilitates the accurate placement of occipital ventricular catheters in ventriculoperitoneal shunt procedures. After 7 years of clinical use, this device has consistently demonstrated its simplicity, user-friendliness, and effectiveness. It enables both experienced surgeons and novices to confidently and accurately position the ventricular catheter to a satisfactory location.

Development of an adjustable patient-specific rigid guide to improve the accuracy of external ventricular catheter placement.

The most common method for external ventricular drain (EVD) placement is the freehand approach, which has reported inaccuracy rates of 12.3%-44.9%, especially in the case of altered ventricular anatomy. Current assistive devices require added time or equipment or do not account for shifted ventricles. To improve the accuracy of emergent EVD placement in the setting of altered ventricular anatomy, the authors designed a patient-specific EVD (PS-EVD) guide. The PS-EVD guide has a tripod base and a series of differently angled inserts that lock in place at multiple rotational positions, allowing for numerous insertion angles. For testing, the authors designed a 3D-printed phantom skull with a gelatin brain analog containing ventricles simulating normal and altered ventricular anatomy. Low-resolution CT scans of the phantom were used to calculate the insertion angle in relation to the standard perpendicular entry. The corresponding insert at the correct rotational position within the base unit was positioned over the entry point on the phantom, and the catheter was inserted. Accuracy was evaluated with repeat CT scans. With normal ventricular anatomy, as well as abnormally shifted ventricles, proper use of the PS-EVD guide led to accurate catheter insertion into the ventricle in trials, as confirmed on coronal and sagittal CT images, including cases in which a perpendicular trajectory, such as with the Ghajar guide, was insufficient. The PS-EVD guide allows consistent and accurate EVD placement in phantom skulls with both normal and altered ventricular anatomy. Further trials comparing this device to the freehand approach are required.

New Preoperative Simulations for the Future of Hydrocephalus Surgery

Ventricular puncture is a basic procedure that neurosurgeons learn in the early stages of their careers and is also performed in ventricular drainage and neuroendoscopic surgery. However, few neurosurgeons are confident in their ability to insert and place a ventricular catheter in the optimal position for ventriculoperitoneal(VP)shunting in a single pass. Even experienced neurosurgical consultants confident in difficult microsurgical procedures are uncomfortable with ventricular catheter placement in VP shunting. Moreover, many neurosurgeons believe that they will never perform a ventricular puncture from the posterior horn of the lateral ventricles. The reason for thinking that ventricular puncture via the anterior horn is safer and more accurate compared with the posterior approach is because the anterior approach can use facial landmarks such as eyes, nose, and ears. However, even with the anterior approach in VP shunting, it is more difficult than with ventricular drainage or neuroendoscopic surgery to achieve accurate placement owing to head rotation, and the success rate has been reported to be as high as 50%. In this article, I introduced "fool proof," which uses preoperative simulation to place a ventricular catheter in the optimal position according to the size and shape of each patient's head and ventricles. The first choice for VP shunting is the right parieto-occipital approach with a posterior horn puncture from Frazier's Point and, for L-P shunting, a paramedian puncture from the 2/3 or 3/4 lumbar interspace.

Transcortical transcatheter ultrasound-assisted technique for deep-seated brain tumors. Technical note.

Surgery of deep-seated brain tumors can be challenging. Several methods have been described to facilitate transcortical approaches, including ultrasound-assisted resection. Ultrasound-guided placement of a standard ventricular catheter is a widely reported technique and has been used to approach these lesions via the transcortical route. We describe how we usually perform this useful technique to assist and enhance the transcortical resection of some deep-seated brain tumors. Standard electromagnetic frameless navigation (S8 Neuronavigation System, Medtronic, Minneapolis, USA) was employed to focus the craniotomy and to plan the trajectory of the ventricular catheter. After dural opening, an ultrasound device (Arietta 850, Hitachi-Aloka Medical, Tokyo, Japan) was used for intraoperative ultrasound (IOUS) assessment. A ventricular catheter was placed from the cortex to the lateral wall of the tumor under direct real-time IOUS visualization to guide the further transcortical dissection. Transcortical transcatheter ultrasound-assisted technique involved minimal time and infrastructure requirements. There were no major technical difficulties during its use, providing confidence and improving subcortical white matter dissection by guiding the route to the tumor. Recent improvement of IOUS image-quality devices offers several attractive options for real-time navigation. The combination of conventional neuronavigation systems with real-time IOUS assessment during the intradural step provides a higher degree of control by improving the execution of the surgery. We hope this description may be a useful tool for some selected cases and contribute to the further enhancement and improvement of this widely used technique.

IMAGINER: improving accuracy with a mixed reality navigation system during placement of external ventricular drains. A feasibility study.

The placement of a ventricular catheter, that is, an external ventricular drain (EVD), is a common and essential neurosurgical procedure. In addition, it is one of the first procedures performed by inexperienced neurosurgeons. With or without surgical experience, the placement of an EVD according to anatomical landmarks only can be difficult, with the potential risk for inaccurate catheter placement. Repeated corrections can lead to avoidable complications. The use of mixed reality could be a helpful guide and improve the accuracy of drain placement, especially in patients with acute pathology leading to the displacement of anatomical structures. Using a human cadaveric model in this feasibility study, the authors aimed to evaluate the accuracy of EVD placement by comparing two techniques: mixed reality and freehand placement. Twenty medical students performed the EVD placement procedure with a Cushing's ventricular cannula on the right and left sides of the ventricular system. The cannula was placed according to landmarks on one side and with the assistance of mixed reality (Microsoft HoloLens 2) on the other side. With mixed reality, a planned trajectory was displayed in the field of view that guides the placement of the cannula. Subsequently, the actual position of the cannula was assessed with the help of a CT scan with a 1-mm slice thickness. The bony structure as well as the left and right cannula positions were registered to the CT scan with the planned target point before the placement procedure. CloudCompare software was applied for registration and evaluation of accuracy. EVD placement using mixed reality was easily performed by all medical students. The predefined target point (inside the lateral ventricle) was reached with both techniques. However, the scattering radius of the target point reached through the use of mixed reality (12 mm) was reduced by more than 54% compared with the puncture without mixed reality (26 mm), which represents a doubling of the puncture accuracy. This feasibility study specifically showed that the integration and use of mixed reality helps to achieve more than double the accuracy in the placement of ventricular catheters. Because of the easy availability of these new tools and their intuitive handling, we see great potential for mixed reality to improve accuracy.

Rapid brain MRI for image-guided ventricular catheter placement in pediatric patients: protocol and preliminary clinical outcomes.

Neuronavigation is a useful adjunct for catheter placement during neurosurgical procedures for hydrocephalus or ventricular access. MRI protocols for navigation are lengthy and require sedation for young children. CT involves ionizing radiation. In this study, the authors introduce the clinical application of a 1-minute rapid MRI sequence that does not require sedation in young children and report their preliminary clinical experience using this technique in their pediatric population. All patients who underwent ventricular catheter placement at a children's hospital using a rapid noncontrast MRI protocol, standard MRI, or head CT from July 2021 to August 2023 were included. Type of procedure, etiology of hydrocephalus, ventricle configuration and size, morphology of ventricles, need for adjunctive intraoperative ultrasound, duration of procedure, accuracy of catheter placement, and need for proximal revision within 90 days were retrospectively recorded and compared across imaging modalities. Sixty-eight patients underwent 83 procedures: 21 underwent CT navigation, 29 standard MRI, and 33 rapid MRI. Patients who received standard MRI more often had tumor etiology, while those who underwent CT and rapid MRI had posthemorrhagic etiology (χ2 = 13.04, p = 0.042). Intraoperative ultrasound was required for 1 patient in the standard MRI group and 1 patient in the CT group. There was no difference in procedure time across groups (p = 0.831). On multivariable analysis, procedure time differed by procedure type, where external ventricular drain placement and proximal revision were faster (p < 0.001 and p < 0.028, respectively). Proximal revision due to obstruction within 90 days occurred in 3 cases (in the same patient with complex loculated hydrocephalus) in the rapid MRI group and 2 cases in the CT group. Although this study was not powered for statistical inference, the authors report on the clinical use of a 1-minute rapid MRI sequence for neuronavigation in hydrocephalus or ventricular access surgery. There were no instances in which intraoperative ultrasound was required as an adjunct for procedures navigated with rapid MRI, and intraoperative time did not differ from that of standard navigation protocols.

ShuntScope-Guided Versus Free-Hand Technique for Ventricular Catheter Placement: A Retrospective Comparative Study of Intraventricular Catheter Tip Position and Complication Rate.

The position of the ventricular catheter (VC) is essential for a proper function of cerebrospinal fluid diversion system. A ShuntScope-guided (SG) method might be helpful in reducing complications. The purpose of this study is to compare the accuracy of catheter placement and the complication and revision rates between SG and free-hand (FH) techniques. This is a retrospective study based on a prospectively acquired database of patients who underwent VC placement between September 2018 and July 2021. Accuracy of catheter placement was graded on postoperative imaging using the 3-point Hayhurst grading system. Complication and revision rates were documented and compared between both groups with an average follow-up period of 20.84 months. Fifty-seven patients were included. The SG technique was used in 29 patients (mean age was 6.3 years, 1.4-27.7 years, 48.1% females), and the FH technique was used in 28 patients (mean age was 26.7 years, 0.83-79.5 years, 67.9% female). The success rate for the optimal placement of the VC with grade I on the Hayhurst scale was significantly higher in the SG group (93.1%) than in the FH group (60.7%), p = 0.012. The revision rate was higher in the FH group with 35.7% versus 20.7% in the SG group, p = 0.211. VC placement using the SG technique is a safe and effective procedure, which enabled a significantly higher success rate and lower revision and complication rate. Accordingly, we recommend using the SG technique especially in patients with difficult anatomy.

Image Quality and Related Outcomes of the ShuntScope-Guided Catheter Implantation in Adult Hydrocephalus: Experience of 63 Procedures.

Ventricular catheter (VC) placement in the selected subset of adult hydrocephalus can be highly challenging due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the success rate of catheter placement. This study evaluates the image qualities of ShuntScope and related surgical outcomes in adults. A retrospective analysis of all adult patients undergoing VC placement using the ShuntScope from November 2011 to July 2022 in the authors' department was performed. Demographic, clinical, and radiologic data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into excellent, medium, and poor, and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter misplacement. A total of 63 ShuntScope-assisted surgeries have been performed on 60 adults. The mean age of the patients was 48.43 years. The most common underlying pathology was a tumor- or cyst-related cerebrospinal fluid (CSF) impairment in 38.33%, followed by a pseudotumor cerebri in 21.66%. The achieved image quality was excellent in 39.68%, medium in 47.62%, and poor in 12.7%. Ideal catheter placement was achieved in 79.37%. There were no intraoperative complications associated with the use of the ShuntScope. The revision rate due to suboptimal proximal VC placement was 4.76% during a mean follow-up period of 27.75 months. A statistical correlation between the image quality and accuracy of the catheter position was observed (p < 0.001). The ShuntScope can be considered an important addition to standard surgical tools in treating a selected subset of adult hydrocephalus. Direct visualization might even help achieve correct placement of the catheter in the cases with blurred vision and limited visual overview.

VP shunt entry area recommender (VPSEAR): A computer-assisted system for VP shunt operation

Hydrocephalus is a condition with an abnormal cerebrospinal fluid (CSF) accumulation in the brain's ventricles resulting in ventricular enlargement. One of the most common surgical treatments for hydrocephalus is the ventriculoperitoneal (VP) Shunt operation. A freehand technique using surface anatomy ventricular catheter placement has been widely used in VP Shunt operations because of its simplicity and low cost. However, this technique trades off with moderate accuracy. To improve accuracy, most existing freehand techniques involved using tools or software to manually measure distances and/or drilling angles from CT or MRI slides. In this work, we developed the first fully automated system VP shunt entry area recommender (VPSEAR) for a pre-planned freehand placement. The program with a user- interface took the patient's CT slides, calculated a circular entry site on a skull, and reported a unique circular entry region. The program integrated several mathematical knowledge and 3-D data processing techniques to ensure high accuracy and acceptable running time. We tested the invented programs on a collection of CT slices of 15 patients with 30 head sides and evaluated the system's accuracy against the traditional Keen's method using 3D Slicer software. We achieved an average accuracy of 95.33% using five internal points evaluation, with accuracy improvement over Keen's method up to 40.33%. The program running time was less than 15 min per head side.

Freehand Ventriculoperitoneal Shunt for Idiopathic Intracranial Hypertension: Technical Note for Slit-Like Ventricle Puncture.

Idiopathic intracranial hypertension (IIH) is a syndrome characterized by elevated intracranial pressure, headache, and papilledema. It is frequently associated with obese women and can result in irreversible vision loss. The ventriculoperitoneal (VP) shunt has been proven to be superior to the lumboperitoneal (LP) shunt in IIH patients, with better clinical outcomes. It has been reported that the accurate placement of the ventricular catheter is highly important for shunt survival. However, a slit-like ventricle pattern, typically seen in the disease, has been considered a great concern and challenge for ventricular catheter placement, primarily for freehand technique. Frameless stereotaxy, ultrasound, and endoscopy have been described to improve the accuracy of catheter insertion. However, intraoperative image guidance is not widely accessible, especially in lower-resource countries, due to the high costs associated with its use. Techniques to improve the accuracy of the freehand VP shunt in IIH are scarce in the literature, and any effort to contribute to its development is valuable and helpful.

Study of Relationship between Location of Ventricular Catheter Tip and Function of the Ventriculoperitoneal (VP) Shunt in Hydrocephalus in Children

Objective: To determine the relationship between location of the ventricular catheter tip and functional status of the ventriculo-peritoneal (VP) shunt in children. Methods: This prospective observational study was conducted in Faculty of Paediatric Surgery under the Department of Paediatric Neurosurgery in Bangladesh Shishu Hospital and Institute (BSH&amp;I) from January 2017 to December 2021. The study included 140 patients who underwent ventriculo-peritoneal shunt using free hand technique. Data obtained for each patient included age, sex, diagnosis including site and side of ventricular catheter placement. Postoperative CT scan of brain were done in all cases and followed up over 2½ to 4½ years. Sixty-three patients were available for follow up. The relationship of location of ventricular catheter tip and function of the ventriculo-peritoneal shunt was analyzed in all 63 patients. Results: Number of the patients included in the study was 140. Accuracy of ventricular catheter tip placement were 55(39.28%) using freehand technique. VP shunts function well in 43(68.25%) patients. Among the 43 patients with well-functioning shunts, 19 were in accurate group, 7 were in suboptimal group and 17 were in inaccurate group. Twenty-six (41.27%) patients had good outcome with normal development. Conclusion: Mechanical malfunction and infection are the most significant problems associated with VP shunts for the treatment of hydrocephalus. A significant proportion of shunt failure is due to inaccurate placement of the ventricular catheter tip. Accurate placement of the catheter tip is highly important to reduce the incidence of shunt malfunction.

Pediatric ventriculoperitoneal shunt: a comparative study between anterior fontanel ultrasound-guided versus conventional cranial end insertion

PurposeVentriculoperitoneal (V-P) shunt is one of the most common neurosurgical procedures in pediatrics for the treatment of hydrocephalus. Shunt failure is one of the common mechanical complications which lead to major morbidities. This study aims to compare between cranial part insertions of the V-P shunts guided by trans-anterior fontanel ultrasound versus conventional insertion.MethodsA prospective comparative randomized study was conducted on 60 pediatric patients aged ≤ 2 years who suffered hydrocephalus and allocated into 2 groups. In the first group (n = 30), the cranial parts of the ventriculoperitoneal shunts were inserted guided by trans-anterior fontanel ultrasound, and in the second group (n = 30), the insertions were by the conventional method. The follow-up duration of the patients was 3 months.ResultsProximal part obstruction of the V-P shunt was found in 3 cases of the conventional group during follow-up with statistical insignificance (p = 0.237) while adequate proximal part location recorded statistical significance (p = 0.0005) in favor of ultrasound-guided group.ConclusionThe use of the anterior fontanel ultrasound guide during ventriculoperitoneal shunt insertion is a feasible, safe, and effective technique for the placement of ventricular catheters in pediatric patients with a patent anterior fontanel.

Image quality and related outcomes of the ShuntScope for catheter implantation in pediatric hydrocephalus—experience of 65 procedures

PurposeVentricular catheter implantation in pediatric hydrocephalus can become a highly challenging task due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the rate of successful catheter placements. This study aims to evaluate ShuntScope’s image qualities and related surgical outcomes in the pediatric population.MethodsA retrospective analysis of all pediatric patients undergoing ventricular catheter placement using the ShuntScope from 01/2012 to 01/2022 in the author’s department was performed. Demographic, clinical, and radiological data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into the categories of excellent, medium, and poor and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter occlusion.ResultsA total of 65 ShuntScope-assisted surgeries have been performed on 51 children. The mean age was 5.1 years. The most common underlying pathology was a tumor- or cyst-related hydrocephalus in 51%. Achieved image quality was excellent in 41.5%, medium in 43%, and poor in 15.5%. Ideal catheter placement was achieved in 77%. There were no intraoperative complications and no technique-related morbidity associated with the ShuntScope. The revision rate due to proximal occlusion was 4.61% during a mean follow-up period of 39.7 years. No statistical correlation between image grade and accuracy of catheter position was observed (p-value was 0.290).ConclusionThe ShuntScope can be considered a valuable addition to standard surgical tools in treating pediatric hydrocephalus. Even suboptimal visualization contributes to high rates of correct catheter placement and, thereby, to a favorable clinical outcome.

Ventricular Peritoneal Shunting Using Modified Keen’s Point Approach: Technical Report and Cases Series

Background: Ventricular peritoneal shunting (VPS) is a frequent procedure in neurosurgery, unfortunately still burdened with a significant rate of complications. The frontal Kocher’s point is the most frequently used landmark for ventricular puncture. Keen’s point (posterior parietal approach) seems to be a valid alternative. We report a newly described access to the lateral ventricle located in posterior temporal area and the results of a large series of adult patients. Methods: Retrospective analysis of a series of 188 cases of VPS performed with this approach. Results: Mean surgical time was 51.5 +/− 13.1 min (range 25–90 min). Twenty-one patients (11.2%) were subjected to revision surgery: eight cases (4.3%) for displacement or malfunction of ventricular catheter, eight cases (4.3%) for abdominal issues, three cases (1.6%) for hardware failure, and two cases (1.1%) for infection. Optimal catheter placement was reached in 90.1%. Conclusions: The modified Keen’s point approach seems to be safe, technically feasible, and reproducible, showing some potential advantages such as short surgical time, precision in ventricular catheter placement, and short tunneling tract. The need for surgical revision is similar to that reported in the literature, while the rate of catheter malpositioning and infections seems to be low; hemorrhages around catheter and seizures were not reported.

Ventriculoperitoneal shunt for brain displacement due to chronic subdural hematoma, using real-time navigated ventriculostomy by three-dimensional robotic C-arm: Technical note

IntroductionVentriculoperitoneal (VP) shunts are widely used in the treatment of hydrocephalus. Optimal ventricular catheter (OVC) placement is required to reduce mechanical dysfunction, particularly when the lateral ventricle is deformed by other factors. We present a novel technique of VP shunt placement through Keen’s point by three dimensional (3D) robotic C-arm navigation in cases of brain displacement due to chronic subdural hematoma (SDH) and post-traumatic hydrocephalus (PTH). MethodsA 74-year-old male with PTH presented with deformed lateral ventricles due to right chronic SDH. A workflow chart of a real-time right ventriculostomy navigation system using a 3D robotic C-arm is introduced. ResultsOVC placement was achieved using virtual surgical planning in a shifted brain case. ConclusionCorrect OVC placement is crucial to the reduction of mechanical dysfunction. Real-time ventriculostomy using 3D robotic C-arm navigation can both reduce the rate of mechanical dysfunction and offer safe and feasible access to the lateral ventricles without causing parenchymal injury, particularly when the ventricles are deformed.

The effect of image-guided ventricular catheter placement on shunt failure: a systematic review and meta-analysis.

Cerebrospinal fluid (CSF) diversion for the treatment of hydrocephalus is one of the most common neurosurgical procedures. Over the years, the development of the neuronavigation system has allowed the surgeon to be guided in real time during the procedures. Nevertheless, to date, the revision rate remains as high as 30-40%. The aim of this study was to investigate the role of intraoperative image guidance in the prevention of shunt failure. We herein report the first literature meta-analysis of image guidance and shunt revision rate in the pediatric population. Principal online databases were searched for English-language articles published between January, 1980, and December, 2021. Analysis was limited to articles that included patients younger than 18years of age at the time of primary V-P shunt. Articles reporting combined results of free-hand and image-guided placement of ventricular catheter (VC) were included. The main outcome measure of the study was the revision rate in relation to the intraoperative tools. Secondary variables collected were the age of the patient and ventricle size. Statistical analyses and meta-analysis plots were done via R and RStudio. Heterogeneity was formally assessed using Q, I2, and τ2 statistics. To examine publication bias was performed a funnel plot analysis. A total of 9 studies involving 2017 pediatric patients were included in the meta-analysis. 55.9% of procedures were carried out with the aid of intraoperative tools, while 44.1% procedures were conducted free hand. The intraoperative tools used were ultrasound (9.1%), electromagnetic neuronavigation (21.07%), endoscope (67.32%), and combined images (2.4%).The image-guided placement of VC was not statistically associated with a lower revision rate. The pooled OR was 0.97 [CI 95% 0.88-1.07] with an I2 statistics of 34%, t2 of 0.018 and a p-value of 0.15 at heterogeneity analysis. Our analysis suggest images guidance during VC shunt placement does not statistically affect shunt survival. Nevertheless, intraoperative tools can support the surgeon especially in patients with difficult anatomy, slit ventricles or complex loculated hydrocephalus.

The O-Arm as an Additional Tool to Confirm Optimal Ventricular Tip Position—A Technical Note

Ventricular catheter placement can be a challenging procedure when treating patients with slit ventricles, despite the use of a neuronavigation system. We report the case of 3 patients with idiopathic intracranial hypertension who had required revision of their ventricular catheter due to malpositioning, despite initial placement using neuronavigation. Owing to the absence of intraoperative computed tomography in our center, we used the O-arm imaging system to confirm placement of the optimal ventricular tip position intraoperatively. Optimal ventricular drain position was achieved in all 3 patients. This short technical note describes an easy technique for using the O-arm to confirm the optimal ventricular drain position.

Reconsidering Ventriculoperitoneal Shunt Surgery and Postoperative Shunt Valve Pressure Adjustment: Our Approaches Learned From Past Challenges and Failures.

Treatment for idiopathic normal pressure hydrocephalus (iNPH) continues to develop. Although ventriculoperitoneal shunt surgery has a long history and is one of the most established neurosurgeries, in the 1970s, the improvement rate of iNPH triad symptoms was poor and the risks related to shunt implantation were high. This led experts to question the surgical indication for iNPH and, over the next 20 years, cerebrospinal fluid (CSF) shunt surgery for iNPH fell out of favor and was rarely performed. However, the development of programmable-pressure shunt valve devices has reduced the major complications associated with the CSF drainage volume and appears to have increased shunt effectiveness. In addition, the development of support devices for the placement of ventricular catheters including preoperative virtual simulation and navigation systems has increased the certainty of ventriculoperitoneal shunt surgery. Secure shunt implantation is the most important prognostic indicator, but ensuring optimal initial valve pressure is also important. Since over-drainage is most likely to occur in the month after shunting, it is generally believed that a high initial setting of shunt valve pressure is the safest option. However, this does not always result in sufficient improvement of the symptoms in the early period after shunting. In fact, evidence suggests that setting the optimal valve pressure early after shunting may cause symptoms to improve earlier. This leads to improved quality of life and better long-term independent living expectations. However, in iNPH patients, the remaining symptoms may worsen again after several years, even when there is initial improvement due to setting the optimal valve pressure early after shunting. Because of the possibility of insufficient CSF drainage, the valve pressure should be reduced by one step (2–4 cmH2O) after 6 months to a year after shunting to maximize symptom improvement. After the valve pressure is reduced, a head CT scan is advised a month later.