Modified ventriculoperitoneal shunt applied to temporary external ventricular drainage.

External ventricular drainage (EVD) is a common procedure in neurosurgical practice. Presently, the three methods used most often include direct EVD (dEVD), long-tunneled external ventricular drains (LTEVDs), and EVD via the Ommaya reservoir (EVDvOR). But they possess drawbacks such as limited duration of retention, vulnerability to iatrogenic secondary infections, and challenges in regulating drainage flow. This study aimed to explore the use of a modified ventriculoperitoneal shunt (mVPS)-the abdominal end of the VPS device was placed externally-as a means of temporary EVD to address the aforementioned limitations. This retrospective cohort study, included 120 cases requiring EVD. dEVD was performed for 31 cases, EVDvOR for 54 cases (including 8 cases with previously performed dEVD), and mVPS for 35 cases (including 6 cases with previously performed EVDvOR). The one-time success rate (no need for further other EVD intervention) for dEVD, EVDvOR, and mVPS were 70.97%, 88.89%, and 91.42%, dEVD vs EVDvOR (P < 0.05), dEVD vs mVPS (P < 0.05), EVDvOR vs mVPS (P > 0.05). Puncture needle displacement or detachment was observed in nearly all cases of EVDvOR, while no such complications have been observed with mVPS. Apart from this complication, the incidence of postoperative complications was 35.48%, 14.81%, and 8.5%, dEVD vs EVDvOR (P < 0.05), dEVD vs mVPS (P < 0.05), EVDvOR vs mVPS (P > 0.05). Mean postoperative retention for EVD was 14.68 ± 9.50 days, 25.96 ± 15.14 days, and 82.43 ± 64.45 days, respectively (P < 0.001). In conclusion, mVPS significantly extends the duration of EVD, which is particularly beneficial for patients requiring long-term EVD.

Exploring the correlation and difference between cerebrospinal fluid in the lateral ventricle and lumbar subarachnoid based on infants with intraventricular hemorrhage treated by the ommaya reservoir.

Objective: To explore the relationship and difference between ventricular and lumbar cerebrospinal fluid(CSF), this study presents equations transforming their measures. By assessing the viability of substituting lumbar puncture, we aim to minimize the associated medical risks and trauma faced by infants with intraventricular hemorrhage(IVH) from anesthesia and lumbar puncture. Methods: We retrospectively analyzed CSF data from 27 infants diagnosed with IVH treated by Ommaya reservoir and lumbar puncture at our center, comprising 35 paired samples. Paired-sample and regression analyses were employed to determine test correlations, differences, and to derive transformation equations for the measurements. Results: Comparative analyses between the CSF from the lateral ventricle and the lumbar vertebrae revealed significant differences in the levels of chloride, glucose, protein, erythrocytes, total cells, and Pandy's test. Specifically:1. Levels of chloride, glucose, protein, and Pandy's test were higher in the lumbar vertebrae.2. Conversely, erythrocyte and total cell counts were higher in the lateral ventricle.There were no significant differences observed for lumbar lactate dehydrogenase(LDH), leukocytes, occult blood, clot, clarity, and color. Nevertheless, significant correlations were identified between various measures, including LDH, glucose, chloride, protein, erythrocyte, leukocyte, total cell count, Pandy's test, occult blood, clot, transparency, and color. Interestingly, the correlation strength and equation fit for each component are inversely proportional to its molecular weight.Notably, well-fitting regression equations were found for LDH, glucose, chloride, protein, leukocytes, erythrocytes, and total cells. Conclusion: In infants with IVH and unobstructed CSF channels, a robust correlation was noted between ventricular CSF sourced via the Ommaya reservoir and lumbar CSF. This correlation tended to be inversely related to molecular weight, with smaller molecular weights showing lesser disparities. Ventricular CSF data could anticipate lumbar CSF trends, and using regression equations with Ommaya-obtained CSF, one can derive approximate values for lumbar CSF.

Ommaya reservoir use in pediatric ALL and NHL: a review at St. Jude Children's Research Hospital.

PURPOSE: The intraventricular route of chemotherapy administration, via an Ommaya Reservoir (OmR) improves drug distribution in the central nervous system (CNS) compared to the more commonly used intrathecal administration. We retrospectively reviewed our experience with intraventricular chemotherapy, focused on methotrexate, in patients with Acute Lymphoblastic Leukemia (ALL) and Non-Hodgkin Lymphoma (NHL). METHODS: Twenty-four patients (aged 7 days - 22.2 years) with 26 OmR placements were identified for a total of 25,009 OmR days between 1990 and 2019. Methotrexate cerebrospinal fluid (CSF) concentrations (n = 124) were analyzed from 59 courses of OmR therapy in 15 patients. Twenty-one courses involved methotrexate dosing on day 0 only, whereas 38 courses involved booster dosing on days 1, 2, or both. We simulated the time CSF methotrexate concentrations remained > 1 µM for 3 days given various dosing regimens. RESULTS: CSF methotrexate exposure was higher in those who concurrently received systemic methotrexate than via OmR alone (p < 10- 7). Our simulations showed that current intraventricular methotrexate boosting strategy for patients ≥ 3 years of age maintained CSF methotrexate concentrations ≥ 1 µM for 72 h 40% of the time. Alternatively, other boosting strategies were predicted to achieve CSF methotrexate concentrations ≥ 1 µM for 72 h between 46 and 72% of the time. CONCLUSIONS: OmR were able to be safely placed and administer intraventricular methotrexate with and without boost doses in patients from 7 days to 22 years old. Boosting strategies are predicted to increase CSF methotrexate concentrations ≥ 1 µM for 72 h.

Augmented Reality-Assisted Placement of Ommaya Reservoir for Cyst Aspiration: A Case Report.

Image guidance technologies can significantly improve the accuracy and safety of intracranial catheter insertions. Augmented reality (AR) allows surgeons to visualize 3D information overlaid onto a patient's head. As such, AR has emerged as a novel image guidance technology that offers unique advantages when navigating intracranial targets. A 71-year-old woman with a history of brain metastasis from breast cancer and prior resection surgery and chemotherapy presented with altered mental status and generalized weakness worse on her left side. Magnetic resonance imaging (MRI) demonstrated right frontotemporoparietal edema with a contrast-enhancing mass. MR perfusion confirmed an active tumor with an enlarging right temporal pole cyst. A cyst aspiration was performed via Ommaya reservoir placement. Neuro-navigation (BrainLab, Munich, Germany) and AR navigation were used to plan the trajectory from the temporal gyrus to the cyst. Post-operative computed tomography (CT) demonstrated good placement of the reservoir, reconstitution of the temporal horn of the lateral ventricle with decreased external mass effect, and no areas of hemorrhage. AR has tremendous potential in the field of neurosurgery for improving the accuracy and safety of procedures. This case demonstrates an encouraging application of AR and can serve as an example to drive expanded clinical use of this technology.

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.

Clinical Safety and Efficiency of the H-Port for Treatment of Leptomeningeal Metastasis.

Objective: To evaluate the usefulness of a cranial implantable chemoport, the H-port, as an alternative to the Ommaya reservoir for intraventricular chemotherapy/cerebrospinal fluid (CSF) access in patients with leptomeningeal metastasis (LM). Methods: One hundred fifty-two consecutive patients with a diagnosis of LM and who underwent H-port installation between 2015 and 2021 were evaluated. Adverse events associated with installation and intraventricular chemotherapy, and the rate of increased intracranial pressure (ICP) control via the port were evaluated for safety and efficacy. These indices were compared with published data of Ommaya (n=89), from our institution. Results: Time-to-install and installation-related complications of intracranial hemorrhage (n=2) and catheter malposition (n=5) were not significantly different between the two groups. Intraventricular chemotherapy-related complications of CSF leakage occurred more frequently in the Ommaya than in the H-port group (13/89 vs. 3/152, respectively, p<0.001). Intracranial hemorrhage during chemotherapy occurred only in the Ommaya group (n=4). The CSF infection rate was not statistically different between groups (14/152 vs. 12/89, respectively). The ICP control rate according to reservoir type revealed a significantly higher ICP control rate with the H-port (40/67), compared with the Ommaya result (12/58, p<0.001). Analyzing the ICP control rate based on the CSF drainage method, continuous extraventricular drainage (implemented only with the H-port), found a significantly higher ICP control rate than with intermittent CSF drainage (33/40 vs. 6/56, respectively, p<0.0001). Conclusion: The H-port for intraventricular chemotherapy in patients with LM was superior for ICP control; it had equal or lower complication rates than the Ommaya reservoir.

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.

Dr Ayub Khan Ommaya (1930-2008): The eventful life of a revolutionary neurosurgeon.

Dr Ayub Khan Ommaya (1930-2008) was a pioneering figure in the field of neurosurgery, with a particular focus on traumatic brain injury. As history books have held, he was a man of great intellect and vision, possessing a rare combination of scientific rigour and compassionate empathy. One of Dr Ommaya's most notable contributions was his development of the Ommaya reservoir, a device used to deliver drugs directly into the brain. This groundbreaking technology transformed the treatment of brain tumours and other neurological disorders, enabling clinicians to administer medications with unprecedented precision and efficacy. From his groundbreaking research on traumatic brain injury to his visionary invention of the Ommaya reservoir, Ommaya's legacy continues to inspire and inform the work of countless medical professionals around the world. This historical paper delves into Ommaya's remarkable life story, highlighting his extraordinary contributions to the field of neurosurgery.

Supraorbital minicraniotomy for open Ommaya reservoir placement in pediatric craniopharyngiomas: a case series and technical report.

OBJECTIVE: Craniopharyngiomas with a predominant cystic component are often seen in children and can be treated with an Ommaya reservoir for aspiration and/or intracystic therapy. In some cases, cannulation of the cyst can be challenging via a stereotactic or transventricular endoscopic approach due to its size and proximity to critical structures. In such cases, a novel placement technique for Ommaya reservoirs via a lateral supraorbital incision and supraorbital minicraniotomy has been used. METHODS: The authors conducted a retrospective chart review of all children undergoing supraorbital Ommaya reservoir insertion from January 1, 2000, to December 31, 2022, at the Hospital for Sick Children, Toronto. The technique involves a lateral supraorbital incision and a 3 × 4-cm supraorbital craniotomy, with identification and fenestration of the cyst under the microscope and insertion of the catheter. The authors assessed baseline characteristics and clinical parameters of surgical treatment and outcome. Descriptive statistics were conducted. A review of the literature was performed to identify other studies describing a similar placement technique. RESULTS: A total of 5 patients with cystic craniopharyngioma were included (3 male, 60%) with a mean age of 10.20 ± 5.72 years. The mean preoperative cyst size was 11.6 ± 3.7 cm3, and none of the patients suffered from hydrocephalus. All patients suffered from temporary postoperative diabetes insipidus, but no new permanent endocrine deficits were caused by the surgery. Cosmetic results were satisfactory. CONCLUSIONS: This is the first report of lateral supraorbital minicraniotomy for Ommaya reservoir placement. This is an effective and safe approach in patients with cystic craniopharyngiomas, which cause local mass effect but are not amenable to traditional Ommaya reservoir placement stereotactically or endoscopically.

Intraoperative ultrasound-guided ventricular cannulation in patients with normal-sized ventricles.

INTRODUCTION: Many pathologies require normal-sized ventricle cannulation, which may be technically challenging even with neuronavigation guidance. This study presents a series of ventricular cannulation of normal-sized ventricles using intraoperative ultrasound (iUS) guidance and the outcomes of patients treated by this technique, for the first time. METHODS: The study included patients who underwent ultrasound-guided ventricular cannulation of normal-sized ventricles (either ventriculoperitoneal (VP) shunting or Ommaya reservoir) between January 2020 and June 2022. All patients underwent iUS-guided ventricular cannulation from the right Kocher's point. The inclusion criteria for normal-sized ventricles were as follows: (1) Evans index <30%, and (2) widest third ventricle diameter <6mm. Medical records and pre-, intra- and post-operative imaging were retrospectively analyzed. RESULTS: Nine of the 18 included patients underwent VP shunt placement; 6 had idiopathic intracranial hypertension (IIH), 2 had resistant cerebrospinal fluid fistula following posterior fossa surgery, and 1 had iatrogenic intracranial pressure elevation following foramen magnum decompression. Nine patients underwent Ommaya reservoir implantation, 6 of whom had breast carcinoma and leptomeningeal metastases and 3 hematologic disease and leptomeningeal infiltration. All catheter tip positions were achieved in a single attempt, and none were placed suboptimally. Mean follow-up was 10 months. One IIH patient (5.5%) had early shunt infection which necessitated shunt removal. CONCLUSION: iUS is a simple and safe method for accurate cannulation of normal-sized ventricles. It provides an effective real-time guidance option for challenging punctures.

Intrathecal delivery of nusinersen using the Ommaya reservoir in a spinal muscular atrophy type 2 patient: a case report / 中华神经科杂志

Ommaya reservoir implantation is generally used in the treatment of hydrocephalus and intraventricular drug administration. Ommaya reservoir implantation in the subarachnoid space of the spinal cord for the intrathecal drug administration has not been carried out in China, and only several reports can be retrieved from PubMed. About 60%-90% of untreated patients with spinal muscular atrophy type 2 (SMA2) who survive to adulthood often have complex scoliosis and joint deformities. Nusinersen is an effective drug for the treatment of SMA2. And the route of administration is intrathecal injection, which is difficult for patients with severe scoliosis. This article summarizes the process of Ommaya reservoir implantation and postoperative drug administration in a patient with complex scoliosis type SMA2, which provides a new method for clinical treatment of this disease.

Effects of modified external ventricular drainage vs. an Ommaya reservoir in the management of hydrocephalus with intracranial infection in pediatric patients.

Background: Hydrocephalus with intracranial infection (HII) may cause pathological changes in brain tissue structure and irreversible damage to the nervous system. However, intracranial infection is a contraindication to ventriculo-peritoneal (VP) shunt surgery, and the prognosis is improved by early infection control and intracranial pressure reduction. This study evaluated the safety and efficacy of the Ommaya reservoir vs. modified external ventricular drainage (M-EVD) in the management of HII in pediatric patients. Methods: This retrospective controlled study included 45 pediatric patients with HII treated with an Ommaya reservoir (n = 24) or M-EVD (n = 21) between January 2018 and December 2022. Clinical outcomes, cerebrospinal fluid (CSF) test results, complications, and outcomes were compared between the Ommaya reservoir and M-EVD groups. Results: No patient died during the follow-up period. The two groups were similar regarding age, sex, admission temperature, weight, preoperative serum protein and albumin concentrations, CSF analysis (white blood cell count, glucose concentration, and protein content), and clinical symptoms (P > 0.05). Both groups had significant changes in the CSF test results postoperatively compared with preoperatively (P < 0.05). In the M-EVD group, the median days for 13 children to remove the external drainage tube and receive VP shunt was 19 days. The longest drainage tube retention time was 61 days, and there was no intracranial infection or serious complication related to the drainage tube. After the placement of the Ommaya, the median time required for CSF to return to normal was 21 days, and a total of 15 patients underwent VP shunt surgery. Conclusion: The Ommaya reservoir and M-EVD are safe and effective for pediatric patients with HII. Both methods reduce the intracranial pressure and alleviate the symptoms of hydrocephalus, although there are differences between the two methods.

Neuroendoscopic surgery combined with Ommaya reservoir placement for cystic craniopharyngiomas: 11 years of experience in a single institution.

INTRODUCTION: Total resection of cystic craniopharyngiomas is challenging, especially for some large cystic tumors, because it is often associated with high recurrence and morbidity rates. Minimally invasive cyst decompression and continuous drainage are appropriate to manage clinical symptoms. We reviewed our experience of the past 11 years to determine the long-term effects of neuroendoscopic surgery (NES) combined with Ommaya reservoir (OR) for the treatment of cystic craniopharyngiomas. METHODS: We retrospectively analyzed the data of 15 adult patients with cystic craniopharyngiomas at a single institution with the primary goal to evaluate the treatment mode with initial adequate decompression of the cyst under visualization and continuous drainage. The study endpoints were functional outcome, cyst volume changes, and tumor progression. RESULTS: The median follow up was 77 (20-136) months. Clinical symptoms, e.g. increased intracranial pressure and visual impairment, could be rapidly improved after NES. The postoperative reduction in cyst volume (p < 0.001) and improvement in Karnofsky performance status (p < 0.001) were significant, and long-term tumor control was achieved in 10 patients (67%). Aspiration from the OR after progression of the tumor's cystic portion remains a major option, with only few patients requiring repeat NES procedures. No patient developed acute or severe clinical symptoms during follow up. CONCLUSIONS: NES could decompress the craniopharyngioma cyst under visualization and enable faster clinical-symptom improvement. The minimally invasive NES combined with OR allowed long-term symptom control in most patients without surgery-related injury. This palliative treatment strategy could be an alternative modality for cystic craniopharyngioma treatment.

Treatment of a symptomatic thalamic pilocytic astrocytoma with reservoir placement and laser interstitial thermal therapy: illustrative case.

BACKGROUND: Treatment of pilocytic astrocytomas (PAs) in children can be challenging when they arise in deep midline structures because complete surgical resection may result in significant neurological injury. Laser interstitial thermal therapy (LITT) has provided an alternative treatment modality for lesions that may not be amenable to resection. However, many patients with PAs may be symptomatic from a compressive cyst associated with the PA, and LITT does not obviate the need for cystic decompression in these patients. OBSERVATIONS: A 12-year-old male presented with left-sided weakness. Magnetic resonance imaging (MRI) revealed an enhancing mass with a large cyst involving the right thalamus and basal ganglia. The patient underwent a reservoir placement for cyst drainage and biopsy of the mass, revealing a pilocytic astrocytoma. He then underwent LITT followed by adjuvant chemotherapy. Sixteen months after LITT, follow-up MRI of the brain revealed no tumor growth. LESSONS: This is the first case to describe reservoir placement to treat the cystic portion of a pilocytic astrocytoma followed by LITT and targeted chemotherapy. Reservoir placement reduced the cyst's mass effect and resolved the patient's symptoms, allowing for treatment options beyond resection.

Preservation of endocrine function after Ommaya reservoir insertion in children with cystic craniopharyngioma.

INTRODUCTION: Children with craniopharyngiomas (CP) can experience significant morbidities caused by extensive surgery and/or radiation. Ommaya reservoir insertion (ORI) into cystic CP represents a minimally invasive approach allowing immediate decompression and aims to avoid additional injuries. The purpose of this study was to determine the surgical outcome and relevance of upfront ORI (± intracystic treatment) for preservation of endocrine function. METHODS: We performed a retrospective chart review of children with CP treated at the Hospital for Sick Children between 01/01/2000 and 15/01/2020. Endocrine function was reviewed at the time of initial surgery and throughout follow-up. New endocrinological deficits related to the index procedure were defined as immediate failure (IF), whereas postoperative duration of endocrinological stability (ES) was analyzed using the Kaplan-Meier method. The rate of IF and ES was compared between the treatment groups. RESULTS: Seventy-nine patients were included and had a median age of 8.3 years (range 2.1-18.0 years); 31 were males. Fifty-three patients with upfront surgical treatment, including 29 ORI and 24 gross total or partial resections had sufficient endocrinological follow-up data. Endocrine dysfunction occurring immediately after the index procedure (IF) was observed in 15 patients (62.5%) in the resection group compared to two patients (6.8%) in the ORI group, odds ratio: 0.05 (CI: 0.01-0.26, p < 0.0001). Excluding those with immediate endocrinological deficits, mean ES after ORI was 19.4 months (CI: 11.6-34.2), compared to 13.4 months (CI:10.6-NA) after surgical resection. CONCLUSIONS: Endocrine function was preserved in patients with upfront ORI (± intracystic treatment), which was confirmed as a minimally invasive procedure with an overall low morbidity profile.

Intrathecal therapy for the management of leptomeningeal metastatic disease: a scoping review of the current literature and ongoing clinical trials.

PURPOSE: Leptomeningeal metastatic disease (LMD) from advanced malignancies has poor prognoses and limited treatments. Intrathecal therapy (ITT) protocols are available, showing variable outcomes. We reviewed the therapeutic and toxicity profiles of ITT in LMD. METHODS: PubMed, EMBASE, Web-of-Science, and Scopus were searched following the PRISMA-ScR guidelines to include studies reporting ITT for LMD. CLINICALTRIAL: gov and Cochrane were searched to identify ongoing clinical trials. RESULTS: We included 27 published studies encompassing 2161 patients and 4 ongoing trials. LMD originated from brain metastases (85.5%), lymphomas (5.4%), high-grade gliomas (4.6%), medulloblastomas (2.3%), and leukemias (2.1%). LMD was mostly diagnosed with the co-presence of neurological-related symptoms and positive imaging and/or cerebrospinal fluid cytology (60.8%). The most common ITT agents were methotrexate (35.9%), cytarabine (21.9%), and thiotepa (8.2%), standalone or combined. Patients received a median of 6.5 ITT cycles (range, 1.0-71.0) via intraventricular (58.8%) or lumbar intrathecal (41.2%) routes. The Ommaya reservoir was implanted in 38.5% cases. Concurrent systemic chemotherapy (45.2%) and/or radiotherapy (30.6%) were used. After 1-3 cycles, 44.7% patients had improved clinical status and 29.9% converted into negative cerebrospinal fluid cytology. The most common ITT-related severe adverse events were neutropenia (6.5%), meningitis (5.2%) and encephalopathy (4.5%). Median freedom from progression was 2.4 months (range, 0.1-59.5) and median overall survival 5.5 months (range, 0.1-148.0). CONCLUSION: Current ITT protocols are variable but effective and well-tolerated in LMD. Ongoing trials are investigating dose-limiting toxicity profiles and long-term overall survival. Future studies should analyze the therapeutic and safety profiles of ITT compared to newer systemic therapies.

Fractionated Gamma Knife radiosurgery after cyst aspiration for large cystic brain metastases: case series and literature review.

Tumor cyst aspiration followed by Gamma Knife radiosurgery (GKRS) for large cystic brain metastases is a reasonable and effective management strategy. However, even with aspiration, the target lesion tends to exceed the dimensions of an ideal target for stereotactic radiosurgery. In this case, the local tumor control rate and the risk of complication might be a critical challenge. This study is aimed to investigate whether fractionated GKRS (f-GKRS) could solve these problems. Between May 2018 and April 2021, eight consecutive patients with nine lesions were treated with f-GKRS in five or ten sessions after cyst aspiration. The aspiration was repeated as needed throughout the treatment course to maintain the cyst size and shape. The patient characteristics, radiologic tumor response, and clinical course were reviewed using medical records. The mean follow-up duration was 10.2 (2-28) months. The mean pre-GKRS volume and maximum diameter were 16.7 (5-55.8) mL and 39.0 (31-79) mm, respectively. The mean tumor volume reduction achieved by aspiration was 55.4%. The tumor volume decreased for all lesions, and symptoms were alleviated in all patients. The median overall survival was 10.0 months, and the estimated 1-year survival rate was 41.7% (95% CI: 10.9-70.8%). The local tumor control rate was 100%. No irradiation-related adverse events were observed. f-GKRS for aspirated cystic brain metastasis is a safe, effective, and less invasive management option for large cystic brain metastases.

Case Report: Clinical and Procedural Implications of Ommaya Reservoir Implantation in Cystic Brain Metastases Followed by Radiosurgery Treatment.

Background: Therapy for large or deep cystic brain metastases is a troublesome procedure in clinical departments. Stereotactic cyst aspiration, combined with Gamma Knife radiosurgery, can be an effective treatment for cystic brain metastases. However, there is still a possibility that a reaccumulation of cystic fluid may lead to poor efficacy or even reoperation. Case presentation: We present a case of a 67-year-old man who was diagnosed with lung cancer brain metastasis. The intracranial lesion seen on imaging appeared to be cystic and located deep inside the brain with associated limb dysfunction. The patient did not respond well to chemotherapy and underwent cyst aspiration with Ommaya reservoir implantation under neuronavigation. Repeated cystic fluid reaccumulation and exacerbation of symptoms occurred during treatment. We performed repeated aspiration via the Ommaya reservoir to control the symptoms and combined it with radiotherapy. During the follow-up period of 14 months, the intracranial tumor was effectively and satisfactorily controlled. Conclusions: We highlight that Ommaya reservoir implantation during stereotactic cyst aspiration is necessary to prevent fluid reaccumulation, thereby avoiding the need for a second surgical procedure.

Case report: The treatment for olfactory neuroblastoma combined with leptomeningeal carcinomatosis via an ommaya reservoir.

Olfactory neuroblastoma is a rare neoplasm that usually presents in the upper nasal cavity. Although its prognosis is highly unfavorable, effective treatment options are still lacking. Moreover, there is no standard treatment for patients with olfactory neuroblastoma that progressed to leptomeningeal carcinomatosis. Here we report an uncommon case of a 59-year-old woman who was diagnosed with olfactory neuroblastoma and leptomeningeal carcinomatosis. For a direct delivery of the drugs to the tumor, and to avoid the impact of lumbar puncture on the patient's quality of life, the intravenous chemotherapy plus intrathecal administration of MTX via an Ommaya reservoir was chosen. The results were striking, with the disappearance of tumor cells in the cerebrospinal fluid and the relief of the patient's symptoms with PR. Our result indicates that chemotherapy via an Ommaya reservoir offers a new potential therapy for patients with meningeal metastases.

Intrathecal Administration of Nusinersen Using the Ommaya Reservoir in an Adult with 5q-Related Spinal Muscular Atrophy Type 1 and Severe Spinal Deformity.

Spinal muscular atrophy (SMA) is a hereditary neuromuscular disorder, typically caused by survival motor neuron 1 (SMN1) gene deletion in chromosome 5q resulting in loss of SMN protein. SMA type 1 progresses rapidly leading to increased mortality usually before the age of 2 years. Nusinersen, the first approved disease-modifying treatment for all 5q-SMA types and ages, is an antisense oligonucleotide administered intrathecally via repeated lumbar punctures. However, adult SMA patients typically present with severe scoliosis and spinal deformity. We present a 28-year-old patient with SMA type 1 and severe spinal deformity, who received nusinersen via a subcutaneously implanted Ommaya reservoir connected with an intrathecal catheter at the thoracic level. The repetitive administrations were completed uneventfully, obviating the need for repeated laborious lumbar punctures and eliminating radiation exposure. In adult SMA patients, performing recurrent lumbar punctures can be technically challenging raising the need for an alternative route of administration. The use of Ommaya reservoirs is a viable, practical for repeated infusions, and safe option for the intrathecal delivery of nusinersen for select cases such as an adult SMA type 1 survivor with severe spinal deformity.