Volumetry and Analysis of Anatomical Variants of the Anterior Portion of the Petrous Apex Outlined by the Kawase Triangle Using Computed Tomography

Abstract

Background?Anterior petrosectomy has become an increasingly used approach for petroclival lesions. This study measures the volume and the anatomical variants of the anterior portion of the petrous apex outlined by the Kawase triangle using computed tomography (CT). Methods?This was a transversal retrospective study. We assessed the anterior petrous apex portion outlined by the Kawase triangle in consecutive patients?>?18 years of age from CT scans of temporal bone stored in an archive system. The volumetry was performed on a workstation. Results?A total of 154 petrosal apex were analyzed in 77 patients (36 men). The average volume of the region outlined by the Kawase triangle was 1.89???0.52 cm3. The volume average in men was 2.01???0.58 cm3, and the average in women was 1.79???0.41 cm3. Intra- and interobserver agreement were both excellent, and there was little variance. Nineteen petrous apex demonstrated anatomical variations. In 18 cases it was pneumatized, and in one case a vascular or nerve-like structure was identified, a report we did not find in the literature. Conclusion?The volumetry of the petrous apex anterior portion outlined by the Kawase triangle can be made by CT with excellent intra- and interobserver agreement and reproducibility. There are anatomical variants in this region that are relevant to surgery.

Assessment of the distribution and volume of air chambers around the inner auditory canal on high-resolution computed tomography scans of the temporal bone

“…The average volumes of quadrants I, II, III, and IV were 66.87 ± 132.16 mm 3 , 67.99 ± 111.47 mm 3 , 236.45 ± 372.47 mm 3 , and 302.37 ± 560.17 mm 3 , respectively. And the average total air chamber volume was 673.68 ± 737.47 mm 3 , which is consistent with the range of 0.93–3.56 cm 3 previously reported for the anterior portion of the petrous apex [10] . This wide range of values means that the relevant anatomic variables in the air chambers around the IAC should be assessed in each individual patient before surgery.…”

“…And the average total air chamber volume was 673.68 ± 737.47 mm 3 , which is consistent with the range of 0.93-3.56 cm 3 previously reported for the anterior portion of the petrous apex. [10] This wide range of values means that the relevant anatomic variables in the air chambers around the IAC should be assessed in each individual patient before surgery. In quadrant I, the air chamber was not developed (air volume, 0) in 37 temporal bones, accounting for 33.6% of the entire study cohort; for quadrants II, III, and IV, 56, 2, and 9 temporal bones were not developed, accounting for 50.9%, 1.8%, and 8.2%, respectively.…”

Abordajes quirúrgicos de los meningiomas petroclivales Parte 2: revisión narrativa y lo que aprendimos con 30 casos

“…[ 11 ] Tanto el acceso fronto-órbito-cigomático como el acceso pterional son utilizados en algunos casos para tumores con mayor extensión en la fosa media o que involucran el seno cavernoso. [ 1 , 14 , 25 ] Este acceso no es adecuado para tumores que se extienden por debajo del meato acústico interno. La petrosectomía anterior asociada con este abordaje puede, en algunos casos, hacer posible la extirpación de tumores que se extienden por debajo del meato acústico interno, pero no habrá una vista directa de la parte inferior del tumor que está siendo extirpado El paciente, colocado en posición supina, tiene la cabeza girada 30º hacia el lado opuesto al tumor.…”

The Learning Curve in Skullbase Surgery Part 2–From the Microsurgical Lab Training to the Operative Room

“…Although dissecting these regions is crucial for understanding the three-dimensional anatomy of all the intricate structures, one of the greatest insights that microsurgical laboratory training can provide is an excellent understanding of the relationship of the brain and nerves with the base of the skull as studied for a specific approach. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Studying the entire head of a corpse not only lets us perform different approaches to the same anatomical region, but also provides us with many neuroimaging insights (►Fig. [9][10][11].…”