Frameless, electromagnetic image-guided ventriculostomy for ventriculoperitoneal shunt and Ommaya reservoir placement

Ommaya reservoir placement using ultrasound guidance via anterior fontanelle combined with frameless electromagnetic neuronavigation in patients with mucopolysaccharidosis type 2: Case reports and review of the literature

Mucopolysaccharidosis type II (MPS II) results from the genetic deficiency of a lysosomal enzyme and is associated with central nervous system (CNS) dysfunction. In Japan, in addition to intravenous enzyme administration, intracerebroventricular enzyme delivery through the Ommaya reservoir has recently gained approval. Nevertheless, the ideal approach for safely implanting the reservoir into the narrow ventricles of infantile MPS II patients remains uncertain. In this report, we present two cases of successful reservoir placement in infantile MPS II patients using ultrasound guidance via the anterior fontanelle, coupled with flameless electromagnetic neuronavigation.

Evaluation of surgical treatment strategies and outcome for cerebral arachnoid cysts in children and adults

OBJECTIVE

The best treatment strategies for cerebral arachnoid cysts (CAC) are still up for debate. In this study, we present CAC management, outcome data, and risk factors for recurrence after surgical treatment, focusing on microscopic/endoscopic approaches as compared to minimally invasive stereotactic procedures in children and adults.

METHODS

In our single-institution retrospective database, we identified all patients treated surgically for newly diagnosed CAC between 2000 and 2022. Microscopic/endoscopic surgery (ME) aimed for safe cyst wall fenestration. Stereotactic implantation of an internal shunt catheter (STX) to drain CAC into the ventricles and/or cisterns was used as an alternative procedure in patients aged ≥ 3 years. Treatment decisions in favor of ME vs. STX were made by interdisciplinary consensus. The primary study endpoint was time to CAC recurrence (TTR). Secondary endpoints were outcome metrics including clinical symptoms and MR-morphological analyses. Data analysis included subdivision of the total cohort into three distinct age groups (AG1, < 6 years; AG2, 6-18 years; AG3, ≥ 18 years).

RESULTS

Sixty-two patients (median age 26.5 years, range 0-82 years) were analyzed. AG1 included 15, AG2 10, and AG3 37 patients, respectively. The main presenting symptoms were headache and vertigo. In AG1 hygromas, an increase in head circumference and thinning of cranial calvaria were most frequent. Thirty-five patients underwent ME and 27 STX, respectively; frequency did not differ between AGs. There were two (22.2%) periprocedural venous complications in infants (4- and 10-month-old) during an attempt at prepontine fenestration of a complex CAC, one with fatal outcome in a 10-month-old boy. Other complications included postoperative bleeding (2, 22.2%), CSF leaks (4, 44.4%), and meningitis (1, 11.1%). Overall, clinical improvement and significant volume reduction (p = 0.008) were seen in all other patients; this did not differ between AGs. Median follow-up for all patients was 25.4 months (range, 3.1-87.1 months). Recurrent cysts were seen in 16.1%, independent of surgical procedure used (p = 0.7). In cases of recurrence, TTR was 7.9 ± 12.7 months. Preoperative ventricular expansion (p = 0.03), paresis (p = 0.008), and age under 6 years (p = 0.03) were significant risk factors for CAC recurrence in multivariate analysis.

CONCLUSIONS

In patients suffering from CAC, both ME and STX can improve clinical symptoms at low procedural risk, with equal extent of CAC volume reduction. However, in infants and young children, CAC are more often associated with severe clinical symptoms, stereotactic procedures have limited use, and microsurgery in the posterior fossa may bear the risk of severe venous bleeding.

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.

Stereotactic guide for posterior approach to lateral ventricle

Background

Free-hand tapping of the lateral ventricle through the posterior approach is a standard procedure. There are occasions, however, when more than one pass is needed. One way to make it easy and safe is to use a neuro-navigation approach. This requires extra setup. Therefore, the authors in this paper describe the use of a simple device to accurately place the catheter tip in the frontal horn.

Main body

The device is rectangular with two open arms with co-linear free ends. Based on axial CT or MR images, a trajectory that travels within the ventricle from the posterior to the anterior horn is chosen. The anterior and posterior points of the trajectory are marked on the scalp. A burr hole is placed at the posterior point. The anterior free end is then attached to the anterior trajectory point on the scalp using an EKG pad and to the posterior to a plug placed in the burr hole. The ventricle is tapped through a central hole in the burr hole plug. All 12 patients had accurate catheter placement at the first attempt using this system.

Short conclusion

This is a simple device that used CT or MR images and surface markings to accurately tap the ventricle.

Evaluating Shunt Survival Following Ventriculoperitoneal Shunting with and without Stereotactic Navigation in Previously Shunt-Naïve Patients

BACKGROUND

Ventriculoperitoneal shunts are used to alleviate elevated intracranial pressure due to either hydrocephalus or idiopathic intracranial hypertension; however, shunt failure is a significant neurosurgical problem. Despite increases in intraoperative stereotactic navigation usage over the past decade, its effect on shunt survival remains unclear.

METHODS

Shunt-naïve pediatric and adult patients receiving ventriculoperitoneal shunting between 2007 and 2015 were identified in a national administrative database. Multivariable logistic and Cox regressions were used to evaluate factors affecting stereotaxy usage and shunt survival. Matched cohorts were generated by propensity score balancing.

RESULTS

Of 9677 patients identified, 932 received image-guided shunt placement. Total shunt failure rate was not associated with stereotaxy use (20.3% with stereotaxy vs. 19.4% without, P = 0.4602). In the matched setting, shunt survival was not extended by use of image guidance during placement (hazard ratio = 1.134, 95% confidence interval 0.923-1.393). Late shunt failures (defined as failures occurring at least 30 days after shunt placement) caused by infection occurred more frequently in the stereotaxy cohort (hazard ratio = 2.207, 95% confidence interval 1.115-4.366), whereas late shunt failures attributable to mechanical shunt failure were more common in the nonstereotaxy cohort (hazard ratio = 1.406, 95% confidence interval 1.002-1.973).

CONCLUSIONS

Our findings suggest stereotaxy use during ventriculoperitoneal shunt placement does not affect shunt survival. Late shunt failures caused by infection occurred more frequently in the stereotaxy cohort, whereas late failures caused by mechanical shunt malfunction were more commonly encountered in the nonstereotaxy cohort.

Placement of Ommaya Reservoirs Using Electromagnetic Neuronavigation and Neuroendoscopy: A Retrospective Study with Cost-Benefit Analysis

BACKGROUND

Placement of intraventricular catheters in oncology patients is associated with high complication rates. Placing Ommaya reservoirs with the zero-error precision protocol (ZEPP), a combination of neuronavigation (AxiEM stereotactic navigation) and direct verification of catheter tip placement with a flexible neuroendoscope, is associated with decreased complication rates as a result of increased catheter placement accuracy. However, the ZEPP costs more than traditional methods of catheter placement, and the question of whether this increased accuracy with the ZEPP is cost-effective is unknown.

METHODS

We performed a single-center retrospective chart review of 50 consecutive ommaya reservoir patient placements between 2010 and 2017. Twenty-five ventricular catheters were placed using the ZEPP protocol, and 25 ventricular catheters were placed using only AxiEM stealth navigation. Postoperative catheter accuracy and complication rates were assessed. A cost-benefit analysis was then conducted to determine if the overall cost for placing Ommaya reservoirs with the ZEPP was effective compared with the alternative method of using neuronavigation alone.

RESULTS

In the non-ZEPP cohort, 10 of 25 catheters were placed within the optimal location compared with 25 of 25 catheters placed in the ZEPP cohort. Three complications occurred in the non-ZEPP cohort: 2 malpositioned catheters required surgical revision and 1 catheter-related hemorrhage resulted in a prolonged stay in the intensive care unit. No complications occurred in the ZEPP cohort. A cost-benefit analysis showed $4784 savings per patient with ZEPP utilization because of the high complication-associated costs.

CONCLUSIONS

Implementation of the ZEPP for verifying ventricular catheter placement in Ommaya reservoirs improved catheter tip accuracy, resulted in lower complication rates, and was more cost-effective when compared with the non-ZEPP cohort, which used only neuronavigation. The ZEPP can be used for ventricular shunt catheter placement to decrease complications and verify catheter tip accuracy in Ommaya or standard ventriculoperitoneal shunts.

Best practices for the use of intracerebroventricular drug delivery devices

For decades, intracerebroventricular (ICV), or intraventricular, devices have been used in the treatment of a broad range of pediatric and adult central nervous system (CNS) disorders. Due to the limited permeability of the blood brain barrier, diseases with CNS involvement may require direct administration of drugs into the brain to achieve full therapeutic effect. A recent comprehensive literature review on the clinical use and complications of ICV drug delivery revealed that device-associated complication rates are variable, and may be as high as 33% for non-infectious complications and 27% for infectious complications. The variability in reported safety outcomes may be driven by a lack of consensus on best practices of device use. Numerous studies have demonstrated that employing strict aseptic techniques and following stringent protocols can dramatically reduce complications. Key practices to be considered in facilitating the safe, long-term use of these devices are presented.

The use of a smartphone-assisted ventricle catheter guide for Ommaya reservoir placement-experience of a retrospective bi-center study

BACKGROUND

For intraventricular chemotherapy (IVC) as part of many oncological treatment protocols, Ommaya reservoir is enabling repeated access to the cerebro-spinal fluid (CSF). The correct placement of the catheter in the ventricle is essential for correct application of drugs, which is enabled by sophisticated techniques such as neuronavigation.

OBJECTIVE

In a bi-center retrospective study, we reviewed our experience using a smartphone-assisted ventricle catheter guide as simple solution for correct Ommaya reservoir placement.

METHODS

Sixty Ommaya reservoirs have been placed in 60 patients between 2011 and 2017 with the smartphone-assisted ventricular catheter guidance technique. Patient characteristics, preoperative frontal and occipital horn ratio (FOHR), postoperative catheter position, and complications were assessed.

RESULTS

The majority of our patients (71.6%) have got narrow or slit-like ventricles (FOHR ≤ 0.4). All Ommaya reservoirs were placed successfully. Fifty-eight ventricular catheters (97%) were inserted at the first and 2 (3%) at the second attempt using the same technique. No immediate perioperative complications were observed. All catheters (100%) could be used for IVC. Postoperative imaging was available in 52 patients. Thirty-two (61.5%) of ventricular catheters were rated as grade I, 20 (38.5%) as grade II, and none (0%) as grade III. Four patients (6.7%) showed postoperative complications during a median follow-up of 8.5 months (hydrocephalus, n = 1; infection, n = 1; parenchymal cyst around catheter, n = 1; shunt revision, n = 1).

CONCLUSIONS

The smartphone-assisted guide offers decent accuracy of ventricle catheter placement with ease and simplicity for a small surgical intervention. We propose this technique as routine tool for Ommaya reservoir placement independent of lateral ventricular size to decrease the rate of ventricle catheter malposition as reasonable alternative to a neuronavigation system.

Intracerebroventricular drug administration

Among the various routes of drug administration, perhaps the least studied is intracerebroventricular (ICV) administration. This route has been shown to be particularly useful in administering to the central nervous system (CNS) drugs that do not cross the blood-brain barrier readily. As such, the ICV route is a valuable option for providing therapeutic CNS drug concentrations to treat patients with CNS infectious and neoplastic diseases. This route of drug administration also has the advantage of minimizing systemic toxicity.

Revisiting the rules for freehand ventriculostomy: a virtual reality analysis

OBJECTIVE Frontal ventriculostomy is one of the most frequent and standardized procedures in neurosurgery. However, many first and subsequent punctures miss the target, and suboptimal placement or misplacement of the catheter is common. The authors therefore reexamined the landmarks and rules to determine the entry point and trajectory with the best hit rate (HtR). METHODS The authors randomly selected CT scans from their institution's DICOM pool that had been obtained in 50 patients with normal ventricular and skull anatomy and without ventricular puncture. Using a 5 × 5-cm frontal grid with 25 entry points referenced to the bregma, the authors examined trajectories 1) perpendicular to the skull, 2) toward classic facial landmarks in the coronal and sagittal planes, and 3) toward an idealized target in the middle of the ipsilateral anterior horn (ILAH). Three-dimensional virtual reality ventriculostomies were simulated for these entry points; trajectories and the HtRs were recorded, resulting in an investigation of 8000 different virtual procedures. RESULTS The best HtR for the ILAH was 86% for an ideal trajectory, 84% for a landmark trajectory, and 83% for a 90° trajectory, but only at specific entry points. The highest HtRs were found for entry points 3 or 4 cm lateral to the midline, but only in combination with a trajectory toward the contralateral canthus; and 1 or 2 cm lateral to the midline, but only paired with a trajectory toward the nasion. The same "pairing" exists for entry points and trajectories in the sagittal plane. For perpendicular (90°) trajectories, the best entry points were at 3-5 cm lateral to the midline and 3 cm anterior to the bregma, or 4 cm lateral to the midline and 2 cm anterior to the bregma. CONCLUSIONS Only a few entry points offer a chance of a greater than 80% rate of hitting the ILAH, and then only in combination with a specific trajectory. This "pairing" between entry point and trajectory was found both for landmark targeting and for perpendicular trajectories, with very limited variability. Surprisingly, the ipsilateral medial canthus, a commonly reported landmark, had low HtRs, and should not be recommended as a trajectory target.