A Novel Method of Locating Foramen Ovale
for Percutaneous Approaches to the Trigeminal
Ganglion

Background: For patients with trigeminal neuralgia who do not respond to medication and for whom surgical approaches are too risky, percutaneous procedures targeting the trigeminal ganglion are the current standard treatment. Percutaneous procedures are performed via the transoval approach under radiologic guidance. Identification of the foramen ovale (FO) under fluoroscopic guidance is an important part of determining the success or failure of the procedures. Objectives: Previous studies have described how to visualize the FO under fluoroscopic guidance, but those methods are limited by poor reproducibility. In this study, we have investigated how to visualize the FO clearly and easily under fluoroscopic guidance. Study Design: Retrospective analysis. Setting: University hospital in Korea. Methods: Seventy-two 3-dimensional facial computed tomography scans without anatomic abnormalities of the skull base were analyzed for verifying the novel method. First, the mandibular angle and the occipital cortical line were overlapped and then turned by 15° oblique rotation using the software package. After these manipulations, the visualization of the FO was graded according to a 4-point scale (0: poor; 1: fair; 2: good; 3: excellent), and the inferior transfacial and oblique angles were measured. Results: This enabled clear visualization of the FO. The mean visual grade of 54 right and 46 left FO (total 100) was 2.74 (0: poor; 1: fair; 2: good; 3: excellent). All recorded FOs had at least grade 2 visibility. Limitations: This study is lacking application in clinical practice and comparative data to the submental view. Conclusions: The mandible angle and the occipital cortex line are obvious anatomic landmarks and are visible even to nonexperienced practitioners. Therefore, our method using these anatomic landmarks can improve the reproducibility and accuracy of FO visualization. Key words: Trigeminal neuralgia, foramen ovale, trigeminal ganglion, 3-dimensional (3D) facial computed tomography (CT) scans

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Evaluation of Anatomoradiological Findings on Trigeminal Neuralgia Patients Using Computed Tomography and Cone-Beam Computed Tomography

Diagnostics ◽

10.3390/diagnostics12010073 ◽

2021 ◽

Vol 12 (1) ◽

pp. 73

Author(s):

Seçil Aksoy ◽

Arzu Sayın Şakul ◽

Durmuş İlker Görür ◽

Bayram Ufuk Şakul ◽

Kaan Orhan

Keyword(s):

Computed Tomography ◽

Trigeminal Neuralgia ◽

Cone Beam Ct ◽

Median Plane ◽

Cone Beam ◽

Foramen Ovale ◽

Percutaneous Procedures ◽

The Right ◽

And Control ◽

Supraorbital Foramen

The study aimed to establish and evaluate anatomoradiological landmarks in trigeminal neuralgia patients using computed tomography (CT) and cone-beam CT. CT images of 40 trigeminal neuralgia (TN) and 40 healthy individuals were retrospectively analyzed and enrolled in the study. The width and length of the foramen rotundum (FR), foramen ovale (FO), foramen supraorbitale, and infraorbitale were measured. The distances between these foramen, between these foramen to the median plane, and between the superior orbital fissure, FO, and FR to clinoid processes were also measured bilaterally. Variations were evaluated according to groups. Significant differences were found for width and length of the foramen ovale, length of the foramen supraorbitale, and infraorbitale between TN and control subjects (p < 0.05). On both sides, FO gets narrower and the length of the infraorbital and supraorbital foramen shortens in the TN group. In most of the control patients, the plane which passes through the infraorbital and supraorbital foramen intersects with impression trigeminale; 70% on the right-side, and 67% in the left-side TN groups. This plane does not intersect with impression trigeminale and deviates in certain degrees. The determination of specific landmarks allows customization to individual patient anatomy and may help the surgeon achieve a more selective effect with a variety of percutaneous procedures in trigeminal neuralgia patients.

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A Novel Method to Locate Intracranial Anatomic Landmarks of Sella Using Three-Dimensional Computed Tomography Reconstruction Images for Endoscopic Endonasal Transsphenoidal Surgery

Journal of Craniofacial Surgery ◽

10.1097/scs.0000000000001944 ◽

2015 ◽

Vol 26 (7) ◽

pp. 2184-2186 ◽

Cited By ~ 3

Author(s):

Pinghua Wu ◽

Huiken Zeng ◽

Xiangliang Tan ◽

Jun Ouyang ◽

Shizen Zhong

Keyword(s):

Computed Tomography ◽

Transsphenoidal Surgery ◽

Three Dimensional ◽

Anatomic Landmarks ◽

Endoscopic Endonasal ◽

Endoscopic Endonasal Transsphenoidal Surgery ◽

Novel Method ◽

Tomography Reconstruction ◽

Computed Tomography Reconstruction

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Computed Tomography Guidance for Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia

Operative Neurosurgery ◽

10.1093/ons/opz400 ◽

2019 ◽

Vol 19 (2) ◽

pp. E117-E121

Author(s):

Bradley T Schmidt ◽

Conrad D Pun ◽

Wendell B Lake ◽

Daniel K Resnick

Keyword(s):

Computed Tomography ◽

Trigeminal Neuralgia ◽

Radiation Exposure ◽

Skull Base ◽

Ct Guidance ◽

Foramen Ovale ◽

Ct Scanner ◽

Ct Guided ◽

Needle Position ◽

Scout Image

Abstract Background Percutaneous glycerol rhizotomy (PGR) is a well-described treatment for trigeminal neuralgia; however, the technique in using surface landmarks and fluoroscopy has not drastically changed since being first introduced. In this paper, we describe a protocol for PGR using computed tomography (CT) guidance based on an experience of over 7 yr and 200 patients. Objective To introduce an approach for PGR using CT guidance and, in doing so, demonstrate possible benefits over the traditional fluoroscopic technique. Methods Using a standard CT scanner, patients are placed supine with head in extension. Barium paste and a CT scout image are used to identify and plan a trajectory to the foramen ovale. A laser localization system built into the CT scanner helps to guide placement of the spinal needle into the foramen ovale. The needle position in the foramen is confirmed with a short-sequence CT scan. Results CT-guided PGR provides multiple benefits over standard fluoroscopy, including improved visualization of the skull base and significant reduction in radiation exposure to the surgeon and staff. Side benefits include improved procedure efficiency, definitive imaging evidence of correct needle placement, and potentially increased patient safety. We have had no significant complications in over 200 patients. CONCLUSION CT-guided PGR is a useful technique for treating trigeminal neuralgia based on better imaging of the skull base, better efficiency of the procedure, and elimination of radiation exposure for the surgeon and staff compared to traditional fluoroscopic based techniques.

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Infratemporal Fossa Vascular Anatomy Pertinent to Percutaneous Access to the Foramen Ovale for Treatment of Trigeminal Neuralgia: A Comparison of Cadaveric Dissection and Computed Tomography Analysis

World Neurosurgery ◽

10.1016/j.wneu.2022.01.013 ◽

2022 ◽

Author(s):

Jesse D. Lawrence ◽

Cletus Cheyuo ◽

Robert A. Marsh

Keyword(s):

Computed Tomography ◽

Trigeminal Neuralgia ◽

Infratemporal Fossa ◽

Vascular Anatomy ◽

Foramen Ovale ◽

Cadaveric Dissection ◽

Percutaneous Access ◽

Tomography Analysis

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Serial 3-Dimensional Computed Tomography and a Novel Method of Volumetric Analysis for the Evaluation of the Osteo-Odonto-Keratoprosthesis

Cornea ◽

10.1097/ico.0b013e31825425d0 ◽

2013 ◽

Vol 32 (4) ◽

pp. 401-406 ◽

Cited By ~ 13

Author(s):

Zuzana Sipkova ◽

Fook Chang Lam ◽

Ian Francis ◽

Jim Herold ◽

Christopher Liu

Keyword(s):

Computed Tomography ◽

Volumetric Analysis ◽

3 Dimensional ◽

Novel Method

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Idiopathic Trigeminal Neuralgia in the Elderly

Pain Neurosurgery ◽

10.1093/med/9780190887674.003.0002 ◽

2019 ◽

pp. 9-12

Author(s):

Kunal Raygor ◽

Anthony Lee ◽

Edward Chang

Keyword(s):

Trigeminal Neuralgia ◽

Elderly Patients ◽

Management Strategies ◽

The Elderly ◽

Surgical Approaches ◽

Percutaneous Procedures ◽

Idiopathic Trigeminal Neuralgia ◽

Surgical Options ◽

Ablative Procedures ◽

Cytochrome P 450

Treatment of trigeminal neuralgia (TN) in the elderly is accomplished using both medical and surgical approaches. Medical therapies are similar to those used in younger patients, but drug-drug interactions are more common in the elderly. Oxcarbazepine is one drug that has fewer side effects due to its bypassing of the cytochrome P-450 metabolic pathway. Surgical options are used for medically refractory TN; the only non-ablative procedure—microvascular decompression (MVD)—provides the most durable pain freedom but may be deferred in patients deemed to be high risk. Both outcomes and complications are similar in young and elderly patients undergoing MVD. In those deemed unsafe for MVD, ablative procedures including stereotactic radiosurgery (SRS) and various percutaneous procedures can be offered. Future studies directly comparing outcomes after MVD and SRS in the elderly with large, prospectively collected databases would help guide management strategies in elderly patients with medically refractory TN.

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Novel fluoroscopic landmark to significantly facilitate the visualization of foramen ovale in treating idiopathic trigeminal neuralgia

Regional Anesthesia and Pain Medicine ◽

10.1136/rapm-2020-102081 ◽

2020 ◽

pp. rapm-2020-102081

Author(s):

Liangliang He ◽

WenXing Zhao ◽

Po-Yi Paul Su ◽

Guili Guo ◽

Jianning Yue ◽

...

Keyword(s):

Trigeminal Neuralgia ◽

Trigeminal Ganglion ◽

Primary Outcome ◽

Horizontal Line ◽

Foramen Ovale ◽

Procedure Time ◽

Sensory Testing ◽

Idiopathic Trigeminal Neuralgia ◽

Time Required ◽

Glycerol Rhizolysis

Background and objectivesAccess through the foramen ovale (FO) is essential in performing trigeminal ganglion injection, glycerol rhizolysis, balloon compression, and radiofrequency thermocoagulation (RFT) to treat idiopathic trigeminal neuralgia (ITN). However, identification of the FO under fluoroscopy can be difficult and time-consuming, and thus exposes patients to increased radiation and procedure risks. Here we present the ‘H-figure’ as a novel fluoroscopic landmark to quickly visualize the FO.MethodsThe H-figure landmark can be recognized as the medial border of the mandible and the lateral edge of the maxilla as the two vertical lines, and the superior line of petrous ridge of temporal bone (S-P-T line) as the horizontal line, and the FO fluoroscopic view is then optimized at the center of the H-figure immediately above the S-P-T line. We applied this landmark in a clinical cohort of 136 patients with ITN who underwent fluoroscopy-guided RFT of the trigeminal ganglion. We also compared the H-figure method with the traditional method. The primary outcome was the total number of fluoroscopic images required to visualize the FO (as a proxy of radiation exposure). Secondary measures included the procedure time required to finalize the FO view and the sensory testing voltage for paresthesia.ResultsWith the H-figure approach we were able to view the FO with an average of 4.2 fluoroscopic shots at an average time of 6.8 min. When compared with the non-H-figure traditional technique, the H-figure method required almost half the fluoroscopic shots in nearly half the procedure duration time, and paresthesia was evoked with half of the voltage.ConclusionThe H-figure is an easy fluoroscopic landmark that can help to view the FO with less radiation and procedure time, and the needles placed with this approach can be closer to the target for the RFT treatment of patients with ITN.

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Improved visualization of the foramen ovale for percutaneous approaches to the gasserian ganglion

Journal of Neurosurgery ◽

10.3171/jns.1994.80.1.0156 ◽

1994 ◽

Vol 80 (1) ◽

pp. 156-159 ◽

Cited By ~ 22

Author(s):

Arthur M. Gerber

Keyword(s):

Trigeminal Neuralgia ◽

Radiation Exposure ◽

Gasserian Ganglion ◽

Foramen Ovale ◽

Content Type ◽

Percutaneous Procedures ◽

Radiopaque Markers ◽

Radiological Studies ◽

Fine Print

✓ Percutaneous procedures for treating trigeminal neuralgia involve the penetration of foramen ovale using cutaneous landmarks and radiological guidance. The placement of radiopaque markers over the commonly used “zygomatic points” in front of the ears provides landmarks on intraoperative radiological studies that facilitate localization of the foramen ovale. Speed and safety of percutaneous trigeminal procedures should be enhanced. There is no increase in radiation exposure over that in other commonly used approaches.

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