Management of large intraventricular meningiomas with minimally invasive port technique: a three-case series

A comparison of brain retraction mechanisms using finite element analysis and the effects of regionally heterogeneous material properties

Finite element (FE) simulations of the brain undergoing neurosurgical procedures present us with the great opportunity to better investigate, understand, and optimize surgical techniques and equipment. FE models provide access to data such as the stress levels within the brain that would otherwise be inaccessible with the current medical technology. Brain retraction is often a dangerous but necessary part of neurosurgery, and current research focuses on minimizing trauma during the procedure. In this work, we present a simulation-based comparison of different types of retraction mechanisms. We focus on traditional spatulas and tubular retractors. Our results show that tubular retractors result in lower average predicted stresses, especially in the subcortical structures and corpus callosum. Additionally, we show that changing the location of retraction can greatly affect the predicted stress results. As the model predictions highly depend on the material model and parameters used for simulations, we also investigate the importance of using region-specific hyperelastic and viscoelastic material parameters when modelling a three-dimensional human brain during retraction. Our investigations demonstrate how FE simulations in neurosurgical techniques can provide insight to surgeons and medical device manufacturers. They emphasize how further work into this direction could greatly improve the management and prevention of injury during surgery. Additionally, we show the importance of modelling the human brain with region-dependent parameters in order to provide useful predictions for neurosurgical procedures.

Successful Surgical Treatment of a Giant Intraventricular Meningioma: A Case Report and Literature Review

In our study, we document the case of a 48-year-old patient who presented at our clinic with various neurological disturbances. Magnetic Resonance Imaging revealed the presence of an intraventricular meningioma located in the body of the left lateral ventricle measuring 60 mm in diameter. This tumor was classified as a giant meningioma, accompanied by a significant amount of digitiform-type edema. A surgical procedure was conducted, resulting in a gross total resection of the tumor. Histopathological analysis identified the tumor as a fibrous meningioma. Postoperative assessments, as well as follow-ups conducted at 3 months and 1 year post-surgery, indicated considerable neurological improvement. The patient exhibited a remission of hemiparesis and gait disturbances along with a marginal improvement in the status of expressive aphasia. This case report underscores the significance of achieving total and safe resection of the tumor and includes an analysis of various cases from the literature, particularly focusing on those that describe minimally invasive surgical approaches and highlight the benefits of radiosurgery in the treatment of giant intraventricular meningiomas.

Impact of Preoperative Mapping and Intraoperative Neuromonitoring in Minimally Invasive Parafascicular Surgery for Deep-Seated Lesions

BACKGROUND

Transsulcal tubular retractor-assisted minimally invasive parafascicular surgery changes the surgical strategy for deep-seated lesions by promoting a deficit-sparing approach. When integrated with preoperative brain mapping and intraoperative neuromonitoring (IONM), this approach may potentially improve patient outcomes. In this study, we assessed the impact of preoperative brain mapping and IONM in tubular retractor-assisted neuro-oncological surgery.

METHODS

This retrospective single-center cohort study included patients who underwent transsulcal tubular retractor-assisted minimally invasive parafascicular surgery for resection of deep-seated brain tumors from 2016 to 2022. The cohort was divided into 3 groups: group 1, no preoperative mapping or IONM (17 patients); group 2, IONM only (25 patients); group 3, both preoperative mapping and IONM (38 patients).

RESULTS

We analyzed 80 patients (33 males and 47 females) with a median age of 46.5 years (range: 1-81 years). There was no significant difference in mean tumor volume (26.2 cm3 [range 1.07-97.4 cm3]; P = 0.740) and mean preoperative depth of the tumor (31 mm [range 3-65 mm], P = 0.449) between the groups. A higher proportion of high-grade gliomas and metastases was present within group 3 (P = 0.003). IONM was related to fewer motor (P = 0.041) and language (P = 0.032) deficits at hospital discharge. Preoperative mapping and IONM were also related to shorter length of stay (P = 0.008).

CONCLUSIONS

Preoperative and intraoperative brain mapping and monitoring enhance transsulcal tubular retractor-assisted minimally invasive parafascicular surgery in neuro-oncology. Patients had a reduced length of stay and prolonged overall survival. IONM alone reduces postoperative neurological deficit.

Resection of an Intraventricular Metastatic Tumor with Minimally Invasive Port Technique: 2-Dimensional Operative Video

The use of minimally invasive port technology has been proposed as a safe method to reduce retractor-induced parenchymal injury, particularly for the resection of deep-seated lesions.1-6 A 69-year-old woman with a history of previous colon cancer surgery presented with gait disturbances and progressive headaches. Magnetic resonance imaging revealed a tumor involving the right ventricular atrium that appeared consistent with metastasis. A parieto-occipital craniotomy was performed on the basis of the preoperatively planned surgical trajectory (Video 1). After the dural incision, the arachnoid was opened down to the sulcus under visualization with microscope. Next, the ViewSite Brain Access system tubular retractor (VBAS; Vycor Medical Inc., Boca Raton, Florida, USA) was introduced toward the lesion under navigation guidance. Once the ventricular atrium was entered, the surface of the tumor came into view. It was coagulated and progressively debulked with ultrasonic aspirator. After the mass was adequately decompressed, a plane of dissection between the ependyma and the tumor could be developed with dynamic angulation of the port in order to allow better visualization. Finally, the tumor could be gently rolled away from the choroid plexus and removed. Meticulous hemostasis was achieved, and the tubular retractor was slowly removed. The patient recovered uneventfully without neurologic deficits on follow-up, and the postoperative magnetic resonance imaging evidenced a complete resection of the tumor. The video illustrates technical nuances and demonstrates the feasibility of minimal access port surgery for the resection of intraventricular lesions with low morbidity and mortality using microsurgical techniques. The patient consented to the publication of her image.

Management of Intraventricular Meningiomas

Intraventricular meningiomas (IVM) are intracranial tumors that originate from collections of arachnoid cells within the choroid plexus. The incidence of meningiomas is estimated to be about 97.5 per 100,000 individuals in the United States with IVMs constituting 0.7% to 3%. Positive outcomes have been observed with surgical treatment of intraventricular meningiomas. This review explores elements of surgical care and management of patients with IVM, highlighting nuances in surgical approaches, their indications, and considerations.

Minimally Invasive Surgery of Deep-Seated Brain Lesions Using Tubular Retractors and Navigated Transcranial Magnetic Stimulation-Based Diffusion Tensor Imaging Tractography Guidance: The Minefield Paradigm

BACKGROUND

Surgical treatment of deep-seated brain lesions is a major challenge for neurosurgeons. Recently, tubular retractors have been used to help neurosurgeons in achieving the targeting and resection of deep lesions.

OBJECTIVE

To describe a novel surgical approach based on the combination of tubular retractors and preoperative mapping by navigated transcranial magnetic stimulation (nTMS) and nTMS-based diffusion tensor imaging (DTI) tractography for the safe resection of deep-seated lesions.

METHODS

Ten consecutive patients affected by deep-seated brain lesions close to eloquent motor/language/visual pathways underwent preoperative nTMS mapping of motor/language cortical areas and nTMS-based DTI tractography of adjacent eloquent white matter tracts, including optic radiations. The nTMS-based information was used to plan the optimal surgical trajectory and to guide the insertion of tubular retractors within the brain parenchyma without causing injury to the eloquent cortical and subcortical structures. After surgery, all patients underwent a new nTMS-based DTI tractography of fascicles close to the tumor to verify their structural integrity.

RESULTS

Gross total resection was achieved in 8 cases, subtotal resection in 1 case, and a biopsy in 1 case. No new postoperative deficits were observed, except in 1 case where a visual field defect due to injury to the optic radiations occurred. Postoperative nTMS-based DTI tractography showed the integrity of the subcortical fascicles crossed by tubular retractors trajectory in 9 cases.

CONCLUSION

The novel strategy combining tubular retractors with functional nTMS-based preoperative mapping enables a safe microsurgical resection of deep-seated lesions through the preservation of eloquent cortical areas and subcortical fascicles, thus reducing the risk of new permanent deficits.

Primary Stereotactic Radiosurgery Provides Favorable Tumor Control for Intraventricular Meningioma: A Retrospective Analysis

The surgical resection of intraventricular meningiomas (IVMs) remains challenging because of their anatomically deep locations and proximity to vital structures, resulting in non-negligible morbidity and mortality rates. Stereotactic radiosurgery (SRS) is a safe and effective treatment option, providing durable tumor control for benign brain tumors, but its outcomes for IVMs have rarely been reported. Therefore, the goal of the present study was to evaluate the SRS outcomes for IVMs at our institution. This retrospective observational study included 11 patients with 12 IVMs with a median follow-up period of 52 months (range, 3-353 months) treated with SRS using the Leksell Gamma Knife. Nine (75%) tumors were located in the trigone of the lateral ventricle, two (17%) in the body of the lateral ventricle, and one (8%) in the third ventricle. Tumor control was achieved in all cases, and seven (55%) decreased in size. Post-SRS perifocal edema was observed in four (37%; three asymptomatic and one symptomatic but transient) patients, all of which were resolved by the last follow-up. SRS appears to provide safe and excellent tumor control for IVMs. A longer follow-up with a larger number of cases is desired for a more solid conclusion.

Clinical outcomes after microsurgical resection of giant lateral ventricular meningiomas

Giant lateral ventricular meningiomas (LVMs), with the largest diameter of at least 5 cm, form a distinct subset. The incidence of giant LVMs is considered to be relatively low. Here, we evaluated clinical characteristics, and clinical outcomes after microsurgical resection, especially functional outcomes and morbidity of giant LVMs. We retrospectively reviewed 49 patients with LVMs, including 18 giant LVMs from 2012 to 2020. And we analyzed clinical, histopathological, surgical, and outcome data at our institution. Giant LVMs were most commonly present in the fourth decade of patients with the male-to-female ratio of 1:2. The most common subtypes were transitional and fibrous. Most lesions were resected via the temporal or parieto-occipital approach in our series. The median volume of blood loss was higher in the giant group (900 vs. 600 ml, p = 0.02). Meanwhile, the median length of hospital stay was prolonged for giant LVMs (20.5 vs. 16.0 days, p < 0.01). The proportion of discharged functional deterioration was higher in giant LVMs (38.9% vs. 6.5%, p = 0.02). However, there was no statistical significance between functional deterioration and tumor size at long-term follow-up (p = 0.28). Giant LVMs patients suffered from neurological and regional complications more commonly, particularly from a postoperative hematoma (4/18 vs. 1/31), and hydrocephalus (2/18 vs. 0/31). Patients with giant LVMs had a high incidence of immediate functional deterioration after microsurgery, and there was no difference in functional deterioration between the giant and non-giant LVMS during long-term follow-up. Microsurgery entails a higher complication rate in giant LVMs. We need to pay special attention to preventing postoperative hematoma and hydrocephalus.

Cerebral corridor creator for resection of trigone ventricular tumors: Two case reports

BACKGROUND

Resection of deep intracranial tumors requires significant brain retraction, which frequently causes brain damage. In particular, tumor in the trigone of the lateral ventricular presents a surgical challenge due to its inaccessible location and intricate adjacent relationships with essential structures such as the optic radiation (OR) fibers. New brain retraction systems have been developed to minimize retraction-associated injury. To date, there is little evidence supporting the superiority of any retraction system in preserving the white matter tract integrity. This report illustrates the initial surgical excision in two patients using a new retraction system termed the cerebral corridor creator (CCC) and demonstrates its advantage in protecting OR fibers.

CASE SUMMARY

We report two patients with nonspecific symptoms, who had trigone ventricular lesions that involved the neighboring OR identified on preoperative diffusion tensor imaging (DTI). Both patients underwent successful surgical excision using the CCC. Total tumor removal was achieved without additional neurological deficit. DTI showed that the OR fibers were preserved along the surgical field. Preoperative symptoms were alleviated immediately after surgery. Clinical outcomes were improved according to the Glasgow-Outcome-Scale and Activity-of-Daily-Living Scale assessments.

CONCLUSION

In the two cases, the CCC was a safe and useful tool for creating access to the deep trigonal area while preserving the white matter tract integrity. The CCC is thus a promising alternative brain retractor.

Clinical Outcome After Microsurgical Resection of Central Neurocytoma: A Single-Centre Analysis of 15 Years

Objective: This study aimed to explore the immediate postoperative and long-term outcomes of central neurocytoma (CN) based on 15 years of experience in our institution.

Methods: This single-institution study collected data of 43 patients with CN who underwent surgery between 2005 and 2020. We reviewed data of clinical, immediate postoperative outcome, and long-term outcome of patients. More specifically, we divided complications into neurological and regional complications groups.

Results: Among the 43 patients with CN who underwent surgery, the transcortical (72.1%) or transcallosal (25.6%) approach was used. There were 18 patients (41.9%) who complained about postoperative neurological complications, including motor weakness (25.6%), memory deficit (18.6%), aphasia (7.0%), and seizure (4.7%). In addition, 18 patients suffered postoperative regional complications such as hydrocephalus (2.3%), hematoma (34.9%), infection (4.7%), and subcutaneous hydrops (2.3%). Only one-quarter of patients had suffered permanent surgical complications. The majority of patients recovered from the deficit and could turn back to normal life. There were no significant differences in the clinical outcomes between transcortical and transcallosal approaches. At a median follow-up of 61.8 months, the 5-year overall survival and progression-free survival were 87.0 and 74.0%, respectively. A multivariate Cox model analysis showed that the extent of resection was not related to progression-free survival. However, the extent of resection was significantly associated with overall survival, and gross total resection decreased the risk of death.

Conclusions: Patients with CN show favorable outcomes after surgery. The transcortical and transcallosal approaches have similar postoperative complication rates and long-term follow-up outcomes. In terms of long-term prognosis, maximal safety resection should be the first choice of CN.