Cochlear-Carotid Interval: Bridging Surgical Insights and Radiological Findings in Cadaveric Human Temporal Bones

Area of Science:

• Otorhinolaryngology
• Neurosurgery
• Anatomy

Background:

• Cochlear implantation is a complex surgery near vital neurovascular structures.
• Electrode displacement into the carotid canal is a rare but serious complication.
• Understanding the relationship between the cochlea and carotid canal is vital for surgical safety.

Purpose of the Study:

• To delineate the anatomical relationship between the cochlea and carotid canal using radiological and cadaveric dissection methods.
• To identify variations in the cochlear carotid interval (CCI).
• To provide data aiding in preventing internal carotid artery injury during cochlear implant surgery.

Main Methods:

• High-resolution computed tomography (HRCT) of 40 cadaveric temporal bones.
• Microscopic dissection of the same 40 temporal bones.
• Measurement of the cochlear carotid interval (CCI) using HRCT and dissection techniques.

Main Results:

• The mean CCI measured 2.08 ± 0.89 mm on HRCT and 2.19 ± 0.85 mm on dissection.
• CCI ranged from 0.48 to 4.25 mm (HRCT) and 0.85 to 4.12 mm (dissection).
• This study is the first to correlate radiological and dissection anatomy of the CCI.

Conclusions:

• The cochlear carotid interval is consistently small, emphasizing the need for meticulous surgical planning in cochlear implant procedures.
• Radiological and dissection data confirm the close anatomical proximity and variations of the CCI.
• Awareness of CCI variations is essential for surgeons to prevent internal carotid artery injury.