Frameless Stereotactic Ommaya Reservoir Placement: Efficacy and Complication Comparison with Frame-Based Technique

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.

Awake intracerebroventricular delivery and safety assessment of oligonucleotides in a large animal model

Oligonucleotide therapeutics offer great promise in the treatment of previously untreatable neurodegenerative disorders; however, there are some challenges to overcome in pre-clinical studies. (1) They carry a well-established dose-related acute neurotoxicity at the time of administration. (2) Repeated administration into the cerebrospinal fluid may be required for long-term therapeutic effect. Modifying oligonucleotide formulation has been postulated to prevent acute toxicity, but a sensitive and quantitative way to track seizure activity in pre-clinical studies is lacking. The use of intracerebroventricular (i.c.v.) catheters offers a solution for repeated dosing; however, fixation techniques in large animal models are not standardized and are not reliable. Here we describe a novel surgical technique in a sheep model for i.c.v. delivery of neurotherapeutics based on the fixation of the i.c.v. catheter with a 3D-printed anchorage system composed of plastic and ceramic parts, compatible with magnetic resonance imaging, computed tomography, and electroencephalography (EEG). Our technique allowed tracking electrical brain activity in awake animals via EEG and video recording during and for the 24-h period after administration of a novel oligonucleotide in sheep. Its anchoring efficiency was demonstrated for at least 2 months and will be tested for up to a year in ongoing studies.

Clinical Application of a Neurosurgical Robot in Intracranial Ommaya Reservoir Implantation

Background: The Ommaya reservoir implantation technique allows for bypass of the blood-brain barrier. It can be continuously administered locally and be used to repeatedly flush the intracranial cavity to achieve the purpose of treatment. Accurate, fast, and minimally invasive placement of the drainage tube is essential during the Ommaya reservoir implantation technique, which can be achieved with the assistance of robots.

Methods: We retrospectively analyzed a total of 100 patients undergoing Ommaya reservoir implantation, of which 50 were implanted using a robot, and the remaining 50 were implanted using conventional surgical methods. We then compared the data related to surgery between the two groups and calculated the accuracy of the drainage tube of the robot-assisted group.

Results: The average operation time of robot-assisted surgery groups was 41.17 ± 11.09 min, the bone hole diameter was 4.1 ± 0.5 mm, the intraoperative blood loss was 11.1 ± 3.08 ml, and the average hospitalization time was 3.9 ± 1.2 days. All of the Ommaya reservoirs were successful in one pass, and there were no complications such as infection or incorrect placement of the tube. In the conventional Ommaya reservoir implantation group, the average operation time was 65 ± 14.32 min, the bone hole diameter was 11.3 ± 0.3 mm, the intraoperative blood loss was 19.9 ± 3.98 ml, and the average hospitalization time was 4.1 ± 0.5 days. In the robot-assisted surgery group, the radial error was 2.14 ± 0.99 mm and the axial error was 1.69 ± 1.24 mm.

Conclusions: Robot-assisted stereotactic Ommaya reservoir implantation is quick, effective, and minimally invasive. The technique effectively negates the inefficiencies of craniotomy and provides a novel treatment for intracranial lesions.

Complications of intracerebroventricular chemotherapy via subgaleal reservoir in primary central nervous system lymphoma: A single-institution experience on 1247 installations in 94 consecutive patients

The implantation of a subgaleal reservoir intracerebroventricular (ICV port) in order to apply ICV chemotherapy in patients with leptomeningeal cancer may be complicated by misplacement of the device, pericatheter leucencephalopathy, hemorrhage and iatrogenic ventriculitis/meningitis. Here we analyzed the occurrence of such complications in patients with primary central nervous system lymphoma (PCNSL) treated with systemic and ICV methotrexate- and cytarabine-based chemotherapy. We retrospectively reviewed the medical records of 94 consecutive patients (1247 installations), who had received an ICV port for intraventricular chemotherapy for treatment of histologically confirmed PCNSL at our institution between September 2005 and October 2018. Infectious and noninfectious complications were systematically recorded including clinical, laboratory, and imaging data. In 9/94 patients (9.6%), a misplacement of the ICV port seen on the postoperative computed tomography scan was corrected immediately and chemotherapy was then continued as planned. In 5/94 patients (5.3%), symptomatic noninfectious complications were observed (four patients with symptomatic pericatheter leucencephalopathy and one patient with surgical scar dehiscence with CSF leak). In 8/94 patients (8.5%), asymptomatic white matter lesions around the catheter were visible on cerebral magnetic resonance imaging after completion of therapy. The rate of infectious complications was 6/94 patients (6.4%). No complication was lethal or required intensive care monitoring. This retrospective study shows that complications of ICV treatment have to be expected in a fraction of patients, however, in this series these complications were manageable and did not result in long-term deficits.

The Use of Ommaya Reservoirs to Deliver Central Nervous System-Directed Chemotherapy in Childhood Acute Lymphoblastic Leukaemia

Prophylactic eradication of central nervous system (CNS) leukaemia is the current standard of care in treating childhood acute lymphoblastic leukaemia (ALL). This is conventionally achieved through regular lumbar punctures with intrathecal injections of methotrexate into the cerebrospinal fluid (CSF). Ommaya reservoirs are subcutaneous implantable devices that provide a secure route of drug delivery into the CSF via an intraventricular catheter. They are an important alternative in cases where intrathecal injection via lumbar puncture is difficult. Among UK Paediatric Principal Treatment Centres for ALL we found considerable variation in methotrexate dosing when using an Ommaya reservoir. We review the current safety and theoretical considerations when using Ommaya reservoirs and evidence for methotrexate dose adjustments via this route. We conclude by summarising the pragmatic consensus decision to use 50% of the conventional intrathecal dose of methotrexate when it is administered via Ommaya reservoir in front-line ALL therapy.

Image-guided Ommaya reservoir insertion for intraventricular chemotherapy: a retrospective series

BACKGROUND

Ayub Ommaya proposed a surgical technique for subcutaneous reservoir and pump placement in 1963 to allow access to intraventricular cerebrospinal fluid (CSF). Currently, the most common indication for Ommaya reservoir insertion (ORI) in adults is for patients with hematologic or leptomeningeal disorders requiring repeated injection of chemotherapy into the CSF space. Historically, the intraventricular catheter has been inserted blindly based on anatomical landmarks. The purpose of this study was to examine short-term complication rates with ORI with image guidance (IG) and without image guidance (non-IG).

METHODS

We retrospectively evaluated all operative cases of ORI from 2000 to 2014 by the senior author. Patient demographic data, surgical outcomes, and peri-operative complications were collected. Accurate placement and early (30-day) morbidity or mortality were considered primary outcomes.

RESULTS

Fifty-five consecutive patients underwent ORI by the senior author over the study period (43.5 ± 16.6 years; 40.0% female). Indications for placement included acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and leptomeningeal carcinomatosis. There were seven (12.7%) total complications: three (37.5%) with no-IG versus four (8.5%) with IG. Catheter malpositions were significantly higher in the non-IG group at 37.5% compared to 2.1%. Catheters were also more likely to require multiple passes with non-IG at 25% compare to 0% with IG. There were no early infections in either group.

CONCLUSIONS

We demonstrate improved accuracy and decreased complications using an image-guided approach compared with a traditional approach. Our results support routine use of intra-operative image guidance for proximal catheter insertion in elective ORI for intraventricular chemotherapy.

Endoscopic-Assisted Ommaya Reservoir Placement: Technical Note

Ommaya reservoir placement has been an option for patients requiring cerebrospinal fluid (CSF) access since the 1960s. It is preferred to repeat lumbar punctures, both in terms of patient comfort and the consistency of intrathecal drug concentration. Technological developments have advanced the placement technique, allowing for better accuracy and reduced complications. Freehand placement was first augmented with pneumoencephalograms and intraoperative computerized tomography (CT), then with optical-based navigation, and finally by utilizing electromagnetic neuronavigation. We outline a method of placement using electromagnetic neuronavigation and intraoperative endoscopic visualization, which allows for both real-time guidance and the confirmation of placement while maintaining tract patency for the entirety of the procedure. We make our incision and burr hole near Kocher’s point. The neuronavigation stylet is placed in a peel-away sheath (Cook Medical, Bloomington, Indiana, US), which allows us to advance into the ventricle under real-time neuronavigation guidance. After the ventricle is entered, the stylet may be withdrawn and an endoscope advanced down the sheath. The intraventricular anatomy and catheter placement are confirmed. The burr hole reservoir is attached to a ventricle catheter that has been trimmed based on trajectory measurement on preoperative imaging. The reservoir-catheter construct can then be placed and the sheath removed from around it. This method provides a high level of confidence in appropriate catheter placement.

Molecular Targeted Therapies for the Treatment of Leptomeningeal Carcinomatosis: Current Evidence and Future Directions

Leptomeningeal carcinomatosis (LMC) is the multifocal seeding of cerebrospinal fluid and leptomeninges by malignant cells. The incidence of LMC is approximately 5% in patients with malignant tumors overall and the rate is increasing due to increasing survival time of cancer patients. Eradication of the disease is not yet possible, so the treatment goals of LMC are to improve neurologic symptoms and to prolong survival. A standard treatment for LMC has not been established due to low incidences of LMC, the rapidly progressing nature of the disease, heterogeneous populations with LMC, and a lack of randomized clinical trial results. Treatment options for LMC include intrathecal chemotherapy, systemic chemotherapy, and radiation therapy, but the prognoses remain poor with a median survival of <3 months. Recently, molecular targeted agents have been applied in the clinic and have shown groundbreaking results in specific patient groups epidermal growth factor receptor (EGFR)-targeted therapy or an anaplastic lymphoma kinase (ALK) inhibitor in lung cancer, human epidermal growth factor receptor 2 (HER2)-directed therapy in breast cancer, and CD20-targeted therapy in B cell lymphoma). Moreover, there are results indicating that the use of these agents under proper dose and administration routes can be effective for managing LMC. In this article, we review molecular targeted agents for managing LMC.

Image Guidance for Placement of Ommaya Reservoirs: Comparison of Fluoroscopy and Frameless Stereotactic Navigation in 145 Patients

OBJECTIVE

Ommaya reservoirs are used for administration of intrathecal chemotherapy and cerebrospinal fluid sampling. Ventricular catheter placement for these purposes requires a high degree of accuracy. Various options exist to optimize catheter placement. We analyze a cohort of patients receiving catheters using 2 different technologies.

METHODS

Retrospective chart review was performed on patients undergoing Ommaya reservoir placement between 2011 and 2014. Most procedures were assisted by either frameless stereotactic neuronavigation or fluoroscopic guidance with pneumoencephalogram. Catheter accuracy, revision rates, perioperative complications, and operative time were measured. Preoperative similarities and differences in diagnosis, demographics, and ventricular size were also recorded to avoid a biased assessment of our results.

RESULTS

One-hundred and forty-five patients were included, 57 using fluoroscopic guidance and 88 using frameless stereotaxy. Common diagnoses in both groups were lymphoma and leptomeningeal disease. Qualitative measures of catheter placement accuracy showed no significant difference between the 2 groups. Proximity to the foramen of Monro favored fluoroscopy by a small margin (8.6 mm vs. 10.2 mm, P = 0.03). Overall revision rates were not significantly different between the groups (3.5% vs. 4.5%, P = 1.00). Early surgical complications occurred in 6.8% of the frameless stereotaxy group and 1.8% of the fluoroscopy group (P = 0.25).

CONCLUSIONS

Ommaya reservoirs can be placed accurately using different methods. Although there are slight differences between fluoroscopy and frameless stereotaxy in quantitative accuracy and procedure time, there is no significant advantage of 1 method over the other when evaluating revision or complication rates. Technique familiarity and surgeon preference may dictate the preferred procedure.