Soft Robotic Deployable Origami Actuators for Neurosurgical Brain Retraction

Metallic tools such as graspers, forceps, spatulas, and clamps have been used in proximity to delicate neurological tissue and the risk of damage to this tissue is a primary concern for neurosurgeons. Novel soft robotic technologies have the opportunity to shift the design paradigm for these tools towards safer and more compliant, minimally invasive methods. Here, we present a pneumatically actuated, origami-inspired deployable brain retractor aimed at atraumatic surgical workspace generation inside the cranial cavity. We discuss clinical requirements, design, fabrication, analytical modeling, experimental characterization, and in-vitro validation of the proposed device on a brain model.

Efficacy of Endoscopic Surgery Management of Craniopharyngiomas in Terms of Tumor Control and Postoperative Morbidity

Background Craniopharyngiomas represent a surgical challenge with resection via either a transcranial or a transnasal approach using microscopy or endoscopy. The selection criteria of the classic transsphenoidal route for the management of craniopharyngiomas were postulated >30 years ago and still are valid today. Aim of the Work to systematically review the literature published discussing the endoscopic management of craniopharyngioma as regard tumor control, symptomatic relief and post-operative morbidity. Materials and Methods This systematic review and meta-analysis was performed in accordance to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses Of Observational Studies in Epidemiology (MOOSE) statements. PRISMA and MOOSE are reporting checklists for Authors, Editors, and Reviewers of Meta-analyses of interventional and observational studies. According to International committee of medical journal association (ICJME), reviewers must report their findings according to each of the items listed in those checklists. Results and Conclusion The extended EEA for suprasellarcraniopharyngiomas avoids brain retraction, permits early exposure of the lesion, provides good visualization of the pituitary gland and stalk and the main vascular structures, and minimizes manipulation of the optic apparatus. The endoscopic technique, both standard and extended approaches, can be considered as a possible surgical treatment for craniopharyngiomas in the modern neurosurgical techniques.

Endoscopic Transorbital Approach to Mesial Temporal Lobe for Intra-Axial Lesions: Cadaveric Study and Case Series (SevEN-008)

BACKGROUND Endoscopic transorbital approach (ETOA) has been proposed as a minimally invasive technique for the treatment of skull base lesions located around mesial temporal lobe (MTL), mostly extra-axial pathology. OBJECTIVE To explore the feasibility of ETOA in accessing intraparenchymal MTL with cadaveric specimens and describe our initial clinical experience of ETOA for intra-axial lesions in MTL. METHODS Anatomic dissections were performed in 4 adult cadaveric heads using a 0° endoscope. First, a stepwise anatomical investigation of ETOA to intraparenchymal MTL was explored. Then, ETOA was applied clinically for 7 patients with intra-axial lesions in MTL, predominantly high-grade gliomas (HGGs) and low-grade gliomas (LGGs). RESULTS The extradural stage of ETOA entailed a superior eyelid incision followed by orbital retraction, drilling of orbital roof, greater and lesser wing of sphenoid bone, and cutting of the meningo-orbital band. For the intradural stage, the brain tissue medial to the occipito-temporal gyrus was aspirated until the temporal horn was opened. The structures of MTL could be aspirated selectively in a subpial manner without injury to the neurovascular structures of the ambient and sylvian cisterns, and the lateral neocortex. After cadaveric validation, ETOA was successfully performed for 4 patients with HGGs and 3 patients with LGGs. Gross total resection was achieved in 6 patients (85.7%) without significant surgical morbidities including visual field deficits. CONCLUSION ETOA provides a logical line of access for intra-axial lesions in MTL. The safe and natural surgical trajectory of ETOA can spare brain retraction, neurovascular injury, and disruption of the lateral neocortex.

Utility of a novel exoscope, ORBEYE, in gravity-assisted brain retraction surgery for midline lesions of the brain

Background: Midline brain lesions, such as falx meningioma, arteriovenous malformations, and cavernous malformations, are usually approached from the ipsilateral interhemispheric fissure. To this end, patients are positioned laterally with the ipsilateral side up. However, some studies have reported the usefulness of gravity-assisted brain retraction surgery, in which patients are placed laterally with the ipsilateral side down or up, enabling surgeons to approach the lesions through the ipsilateral side or through a contralateral interhemispheric fissure, respectively. This surgery requires less brain retraction. However, when using an operative microscope, performing this surgery requires the surgeon to operate in an awkward position. A recently developed high-definition (4K-HD) 3-D exoscope system, ORBEYE, can improve the surgeon’s posture while performing gravity-assisted brain retraction surgery. Methods: We report five cases with midline brain tumors managed by resectioning with gravity-assisted brain retraction surgery using ORBEYE. We also performed an ergonomic analysis of gravity-assisted brain retraction surgery with a craniotomy model and a neuronavigation system. Results: Gravity-assisted brain retraction surgery to the midline brain tumors was successfully performed for all five patients, using ORBEYE, without any postoperative neurological deficit. Conclusion: Gravity-assisted brain retraction surgery to the midline brain lesions using ORBEYE is feasible, and ORBEYE is ergonomically more favorable than a microscope. ORBEYE has the potential to generalize neurosurgical approaches considered difficult due to the surgeon’s awkward position, such as gravity-assisted brain retraction surgery.

Hybrid Fluoroscopic and Neurophysiological Targeting of Responsive Neurostimulation of the Rolandic Cortex

BACKGROUND Precise targeting of cortical surface electrodes to epileptogenic regions defined by anatomic and electrophysiological guideposts remains a surgical challenge during implantation of responsive neurostimulation (RNS) devices. OBJECTIVE To describe a hybrid fluoroscopic and neurophysiological technique for targeting of subdural cortical surface electrodes to anatomic regions with limited direct visualization, such as the interhemispheric fissure. METHODS Intraoperative two-dimensional (2D) fluoroscopy was used to colocalize and align an electrode for permanent device implantation with a temporary in Situ electrode placed for extraoperative seizure mapping. Intraoperative phase reversal mapping technique was performed to distinguish primary somatosensory and motor cortex. RESULTS We applied these techniques to optimize placement of an interhemispheric strip electrode connected to a responsive neurostimulator system for detection and treatment of seizures arising from a large perirolandic cortical malformation. Intraoperative neuromonitoring (IONM) phase reversal technique facilitated neuroanatomic mapping and electrode placement. CONCLUSION In challenging-to-access anatomic regions, fluoroscopy and intraoperative neurophysiology can be employed to augment targeting of neuromodulation electrodes to the site of seizure onset zone or specific neurophysiological biomarkers of clinical interest while minimizing brain retraction.

Endoscopic-Assisted Resection of Anterior Foramen Magnum Meningiomas through a Midline Suboccipital Subtonsillar Approach

Objective This study was aimed to demonstrate the resection of anterior foramen magnum meningiomas through an endoscopic-assisted posterior midline suboccipital subtonsillar approach. Design This study was designed with illustration of the surgical steps and safety of this approach. Setting Evidence of cerebrospinal fluid (CSF) cleft between the tumor and brainstem on MRI was studied (Fig. 1A and B). Preoperative tracheotomy was considered in cases of preoperative dysphagia to prevent any further neurological deterioration due to the bilateral access through the lower cranial nerves corridors. Semisitting position with extensive electrophysiological neuromonitoring and transesophageal echocardiogram was adopted. A standard midline incision with bilateral suboccipital craniotomy and C1-laminotomy was performed (Fig. 2A). After partial resection and elevation of the tonsils, tumor was debulked unilaterally around the lower cranial nerves and the vertebral artery, devascularized from the clival dura and then dissected from the brainstem (Fig. 2B, C). Endoscopic-assisted removal of its anterior portion followed. The same procedure was repeated from the opposite site for the contralateral portion, before approaching the purely anterior part with endoscope assistance (Fig. 2D). Participants Four consecutive patients were included in the study. Main Outcome Measures Grade of tumor resection and outcome (mRS) were primary measurement of this study. Results Clinical outcome and grade of resection are comparable to other series of patient treated with other foramen magnum approaches (Fig. 1C and D). Conclusion Anterior foramen magnum meningiomas can be safely removed through this relatively faster midline suboccipital approach with bilateral exposure of lower cranial nerves (CNs) and vertebral arteries and lower approach-related morbidity (no condyle drilling). The surgical corridor is created by the tumor during debulking reducing need for brain retraction and the removal of the anterior dural attachment coagulated under the microscope is verified and completed endoscopically with pituitary curettes (Simpson's grade II) (Fig. 1C and D).The link to the video can be found at: https://youtu.be/9eACAJVwQBs.

Tentorial Peeling: Surgical Extradural Navigation to Protect the Temporal Lobe in the Focused Combined Transpetrosal Approach

BACKGROUND Transpetrosal approaches have been used for treatment of tumors in the petroclival region for many years. Injury to the temporal lobe, however, has been a potential drawback of the techniques described to date. OBJECTIVE To describe modifications of the transpetrosal surgical technique, which allows extradural manipulation of the temporal lobe during the focused combined transpetrosal approach. This extra layer of protection avoids mechanical brain retraction, direct trauma to the temporal lobe and disruption of the local venous structures. METHODS The present manuscript describes an innovative technical nuance based on the combination of the focused combined transpetrosal approach, the peeling of the dural layers of the tentorium, and the reverse peeling of the middle fossa dura mater. Ample illustrative material is provided and illustrative cases are presented. CONCLUSION Peeling of the dural layers of the tentorium is a promising modification of the transpetrosal approach to increase the safety of the temporal lobe manipulation.