Anatomic Characteristics of Intrapetrous Carotid Artery: A 3-Dimensional Segmentation Study on Head Computed Tomography Scan

Abstract

The intrapetrous portion of internal carotid artery (IPCA) is one of the most unexplored anatomical regions, and its three-dimensional reconstruction in living subjects is still missing. The present study aims at describing IPCA on 3D models extracted from head CT-scans.The intrapetrous carotid artery was manually segmented on head CT-scans of 100 healthy patients free from vascular and neurological pathologies (50 males and 50 females aged between 18 and 91 years). Angles of the posterior and anterior genu, diameter and length of the horizontal portion, and volume of the entire canal were calculated through VAM® software. Statistically significant differences according to sex and side were assessed through two-way ANOVA test (p<0.05). Correlation of each measurement with age was calculated as well.On average the angles of the posterior and anterior genu were 120.1±10.4° and 118.0±10.0° in males, 119.5±9.2° and 117.6±10.3° in females, respectively, without statistically significant differences according to sex or side (p>0.05). Average length and diameter of the horizontal part were respectively 25.5±2.9 mm and 5.8±0.8 mm in males, 24.0±2.3 mm and 5.3±0.8 mm in females. The volume of IPCA was 0.941±0.215 cm 3 in males, and 0.752±0.159 cm 3 in females. Length and diameter of horizontal portion, and volume of IPCA showed statistically significant differences according to sex (p<0.05). No correlation with age was found.This study first provided data concerning not only linear and angular measurements, but also volumes of IPCA, useful in planning surgical interventions of the cranial base.

Carotid-artery cochlear dehiscence

“…In addition, this type of anatomical change, especially canal bony dehiscence, may pose significant surgical risk during otologic procedures [1][2][3][4] . In general, middle ear surgeries are common, safe procedures, but always subject to complications, especially when anatomical changes such as ectopia and carotid-artery cochlear dehiscence are not previously recognized.…”

“…In this intratemporal course, the ICA may present bone dehiscence in approximately 1% of the cases, and positioning and location changes are even rarer [1][2][3] .…”