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Introducing a preoperative image simulation technique to streamline the visualization of the foramen ovale in percutaneous microcompression. Twenty-five trigeminal neuralgia patients were included in the study. Preoperative cranial computed tomography scans were processed with 3D Slicer software to create simulated fluoroscopic skulls. The angulations required for precise visualization of the foramen ovale were established via simulated anteroposterior imaging. These simulations informed the C-arm's angulations for foramen ovale targeting during surgery. The preoperative simulations accurately forecasted skull rotation angulations, aligning closely with intraoperative observations with negligible discrepancies (0–2 degrees). In 17 patients, the foramen ovale was distinctly visible, while in 8 patients, it was partially obscured yet discernible using the simulated angles. Nonvisible of the foramen ovale did not occur. Postoperative pain relief and complications were recorded. Based on our initial findings, the application of preoperative image simulation shows significant referential value in achieving accurate visualization of the foramen ovale in percutaneous microcompression for trigeminal neuralgia. [ABSTRACT FROM AUTHOR]

Trigeminal neuralgia may be treated via percutaneous access to the foramen ovale (FO). Vascular complications associated with the needle trajectory can result in serious morbidity and mortality. This study aimed to correlate the vascular relationships of the FO at the skull base via cadaveric dissections and computed tomography (CT). Two fresh cadaver heads were injected with red and blue latex to delineate arteries and veins. Neck and infratemporal fossa dissections were carried out to delineate the vascular relationships of the FO. High-resolution head CT images of adult patients undergoing neurosurgical evaluations or procedures were analyzed for distances and sizes of skull base foramina in the infratemporal fossa. Three infratemporal fossa dissections (2 cadaveric specimens) were performed. Mean distance of FO to internal carotid artery was 2.4 ± 0.12 cm, and mean distance of FO to middle meningeal artery was 0.8 ± 0.16 cm. Head CT images of 52 patients (104 sides) with 1-mm axial slice thickness were analyzed. Area of the FO was 31.1 ± 9.6 mm2. Distance of FO to internal carotid artery was 1.70 ± 0.31 cm, and distance of FO to middle meningeal artery was 0.73 ± 0.61 cm. Cadaveric delineation of vascular structures in the infratemporal fossa correlates with head CT imaging and may be used to accurately plan percutaneous access to the FO. Inadvertent puncture of the extracranial internal carotid artery is nearly impossible with good technique. The most likely source of percutaneous vascular injury is the middle meningeal artery and distal branches of the maxillary artery. [ABSTRACT FROM AUTHOR]

We have been using computed tomography (CT) guidance for percutaneous glycerol rhizotomy (PGR) for the last 7 years. As a quality improvement exercise, we recently began using general anesthesia (GA) with the use of a laryngeal mask airway (LMA) because of our perception that the procedure went faster and that there was less radiation exposure because of less patient movement. We aim to compare PGR radiation exposure and procedural time between patients receiving local anesthetic with sedation and those receiving GA/LMA. A single-center historical cohort study was performed using patients treated with PGR between 2017 and 2019. Ninety-two surgeries were conducted during the study period: 64 surgeries had local anesthetic with intravenous sedation, and 28 surgeries had deeper anesthetic with LMA. Data analyzed included the number of CT sequences obtained, needle placement time, and total radiation dose. Use of GA/LMA resulted in a 23% decrease in mean radiation dose (565.5 vs. 436.1 μGy × cm, P = 0.014), number of CT sequences required (7.4 vs. 5.7, P = 0.003), and needle placement time (12.8 vs. 9.8 minutes, P = 0.006). Additionally, 10 patients underwent multiple glycerol rhizotomies during the collection period with both anesthetic types being used at least once. Seven of 10 patients (70.0%) had a reduction in total radiation dose, number of CT sequences obtained, and needle placement time when GA/LMA was used. There were no procedure- or anesthetic-related complications in this patient cohort. The use of GA/LMA during PGR is associated with decreased radiation exposure without increased anesthetic complications. [ABSTRACT FROM AUTHOR]

Background A wide variety of lesions may develop in the cavernous sinus region, including tumors or pseudotumors of inflammatory origin. Sometimes imaging is insufficient to ascertain a pathologic diagnosis. Percutaneous biopsy performed through the foramen ovale route may aid therapeutic decision making, avoiding unnecessary open surgery when lesions are confirmed to be nonsurgical or unresectable. We conducted a systematic review to determine the efficacy of percutaneous biopsy of cavernous sinus lesions. Method A systematic search in PubMed, LILACS, Web of Science, and Scopus yielded 4495 potentially eligible abstracts. Fourteen studies describing 75 biopsy procedures for lesions in the cavernous sinus region were reviewed. The primary outcome measure was diagnostic success. Data were analyzed according to standard systemic review techniques. Results A diagnosis was obtained in 65 of the 75 cases described in the literature. Among all series, only 3 patients had permanent deficits. No individual studies reported mortality. The histopathologic evaluation revealed neoplastic diseases in 58 lesions. Meningiomas were found in 26 biopsy samples. Nonneoplastic diseases, originating from infectious, inflammatory, or deposition diseases, accounted for 6 biopsy samples. Conclusions Percutaneous biopsy of cavernous sinus lesions is effective for diagnosis. Biopsy can be performed in patients with cavernous sinus masses, especially when neuroimaging fails to provide sufficient histopathologic data. [ABSTRACT FROM AUTHOR]

Background Identification and protection of the cochlea during anterior petrosectomy is key to prevent hearing loss. Currently, there is no optimal method to infer the position of the cochlea in relation to the Kawase quadrangle; therefore, damage to the cochlea during anterior petrosectomy remains a substantial risk. Objectives To identify and define landmarks available during anterior petrosectomy to locate the cochlea and prevent its damage. Methods The Kawase approach was simulated in 11 cadaveric specimens. After a subtemporal craniotomy, foramen spinosum and ovale were identified. Anterior petrosectomy was performed, and the upper dural transitional fold (UDTF) was identified. Two virtual lines, from foramen spinosum (line A), and the lateral rim of the foramen ovale (line B), were projected to intersect the UDTF perpendicularly. The cochlea was exposed, and the distances between lines A and B and the closest point of the outer rim and membranous part of the cochlea were measured. Results The average distance between line A to the bony and membranous edges of the anteromedial cochlea was −0.62 ± 1.38 mm and 0.38 ± 1.63 mm, respectively. The average distance between line B to the bony and membranous edges of the cochlea was 1.82 ± 0.99 mm and 2.78 ± 1.29 mm, respectively. Line B (cochlear safety line) never intersected the cochlea. Conclusions The cochlear safety line is a reliable landmark to avoid the cochlea during the Kawase approach. When expanding the anterior petrosectomy posteriorly, the cochlear safety line can be used as a reliable landmark to prevent exposure of the cochlea, thus preventing hearing loss. [ABSTRACT FROM AUTHOR]

Trigeminal nerve balloon compression (TNBC) 1-3 can provide immediate therapeutic relief to patients suffering from trigeminal neuralgia. This is a particularly effective treatment option for patients who are not eligible for surgical procedures (i.e., elderly patients or patients with multiple comorbidities) or for patients who have had an insufficient response to microvascular decompression. TNBC can also be used as a bridge treatment before stereotactic radiosurgery. Use of intraoperative computed tomography−like images using a C-arm system (DYNA-CT) imaging facilitates the TNBC procedure. 4,5 Three-dimensional DYNA-CT imaging with needle guidance allows for precise needle advancement and insertion through the foramen ovale. DYNA-CT enables the direct visualization and avoidance of vascular structures such as the carotid or internal maxillary arteries and results in decreased procedure times and complications. The authors present a step-by-step video demonstrating the use of intraoperative DYNA-CT needle guidance for TNBC (Video 1). A Siemens Artis Zee Biplane system is used for the procedure. A comprehensive description of all elements of the procedure is provided including balloon preparation, needle trajectory planning, needle advancement, 3-dimensional confirmation of the needle's depth and path, balloon placement, balloon inflation, and balloon removal. Tips and optimal strategies are presented. Advantages of using DYNA-CT for needle guidance include the reduction of fluoroscopy dose and fluoroscopy time. The average dose area product during conventional percutaneous balloon compression in prior studies was 1137 mGycm2, with a mean fluoroscopic time of 62 seconds. 6 In our experience, the mean fluoroscopy dose is 274 mGycm2 and the total fluoroscopic time is about 45 seconds. Furthermore, during the DYNA-CT acquisition, the neurointerventional team stays outside the room during the DYNA-CT, which reduces the cumulative radiation to the operator. DYNA-CT needle guidance facilitates precise advancement of the needle into the foramen ovale and positioning of the balloon in the Meckel cave during TNBC. It is a safe and feasible technique that allows for the visualization and avoidance of important structures such as the internal carotid artery or the internal maxillary artery, resulting in decreased procedure times and complications. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to describe the anatomic trajectory of the extracranial needle for percutaneous rhizotomy and correlate this with structures at risk during such a procedure. Methods Six sides from 3 frozen fresh Caucasian heads were used in this study. Hartel anatomic landmarks for percutaneous trigeminal rhizotomy procedures were used. A free hand technique was then used, and intraprocedural visualization of the needle was performed with fluoroscopy. When the procedure was completed, the face was dissected along with the needle pathway up to the foramen ovale in order to evaluate for any damaged structures. Results On all sides, the needle passed lateral to the buccinator muscle and near the parotid duct to then pierce the superior head of the lateral pterygoid muscle to enter the infratemporal fossa. This placed the needle near the buccal nerve on all sides, although no direct injury was noted. Although very near, no branches of the facial nerve or artery were damaged. On 1 side, the maxillary artery was pierced. Conclusions To our knowledge, this is the first study to describe the detailed extracranial anatomic needle pathway using the Hartel approach. Such data might help surgeons better recognize potential complications from such procedures. [ABSTRACT FROM AUTHOR]