Comprehensive anatomy of the foramen ovale critical to percutaneous stereotactic radiofrequency rhizotomy: cadaveric study of dry skulls.

J Neurosurg 2019 Apr 19:1-9. Epub 2019 Apr 19.

1Department of Neurosurgery, University of Minnesota, Minneapolis, Minnesota.

OBJECTIVEPercutaneous stereotactic radiofrequency rhizotomy (PSR) is often used to treat trigeminal neuralgia, a serious condition that results in lancinating, episodic facial pain. Thorough understanding of the microsurgical anatomy of the foramen ovale (FO) and its surrounding structures is required for efficient, effective, and safe use of this technique. This morphometric study compares anatomical and surgical orientations to identify the variations of the FO and assess cannulation difficulty.METHODSBilateral foramina from 174 adult human dry skulls (348 foramina) were analyzed using anatomical and surgical orientations in photographs from standardized projections. Measurements were obtained for shape, size, adjacent structures, and morphometric variability effect on cannulation. The risk of potential injury to surrounding structures was also assessed.RESULTSThe authors identified 6 distinctive shapes of the FO and 5 anomalous variants from the anatomical view, and 6 shapes from the surgical view. In measurements of surface area of this foramen obtained using the surgical view, loss (average 18.5% ± 5.7%) was significant compared with the anatomical view. Morphometrically, foramen size varied significantly and obstruction from a calcified pterygoalar ligament occurred in 7.8% of specimens. Importantly, 8% of foramina were difficult to cannulate, thus posing a 12% risk of inadvertent cannulation of the foramen lacerum.CONCLUSIONSSignificant variability in the FO's shape and size probably affected its safe and effective cannulation. Preoperative imaging by 3D head CT may be helpful in predicting ease of cannulation and in guiding treatment decisions, such as a percutaneous approach over microvascular decompression or radiosurgery.

Download full-text PDF

Source
http://dx.doi.org/10.3171/2019.1.JNS18899DOI Listing

Still can't find the full text of the article?

We can help you send a request to the authors directly.
April 2019
4 Reads

Publication Analysis

Top Keywords

shape size
8
radiofrequency rhizotomy
8
stereotactic radiofrequency
8
anatomical view
8
dry skulls
8
anatomical surgical
8
surgical orientations
8
surrounding structures
8
surgical view
8
foramen ovale
8
anatomy foramen
8
foramen
5
cannulation
5
variants anatomical
4
anomalous variants
4
identified distinctive
4
distinctive shapes
4
shapes anomalous
4
average 185%
4
view
4

References

(Supplied by CrossRef)
[Intracisternal length of the trigeminal nerve.]
Lang et al.
Neurochirurgia (Stuttg) 1984
A morphometric study of foramen ovale
Somesh et al.
Turk Neurosurg 2011
[Microsurgical treatment of trigeminal neuralgia. Results and prognostic factors of microsurgical vascular decompression.]
Szapiro et al.
Neurochirurgie 1986
On the incidence of the foramen of Civinini and the porus crotaphiticobuccinatorius in American whites and Negroes
Chouke et al.
Anat Rec 1946
The morphology and morphometry of the foramina of the greater wing of the human sphenoid bone
Reymond et al.
Folia Morphol (Warsz) 2005

Similar Publications