Retrosigmoid Craniotomy and Intradural Variations: Role of Patient-Specific Preoperative Imaging to Identify...

Area of Science:

• Neurosurgery
• Skull Base Surgery
• Anatomy

Background:

• The retrosigmoid approach is a cornerstone in posterior skull base surgery.
• Identifying safe surgical corridors is essential for minimizing complications.
• Patient-specific anatomical variations can impact the efficacy and safety of surgical approaches.

Purpose of the Study:

• To review surface and imaging landmarks for the retrosigmoid approach.
• To discuss patient-specific variations in these landmarks.
• To optimize the planning of retrosigmoid approach extensions.

Main Methods:

• Review of patient positioning and surface landmarks for retrosigmoid craniotomy.
• Analysis of key anatomical structures for transmeatal, suprameatal, suprajugular, and transtentorial extensions.
• Evaluation of imaging modalities (MRI, CT) for landmark identification.

Main Results:

• Dural sinus position relative to zygomatic-inion and digastric notch lines identified on MRI.
• Semicircular canals, vestibular aqueduct, and jugular bulb evaluated on CT for transmeatal drilling.
• Labyrinth, carotid canal, incisural structures, and jugular bulb evaluated for anterior, transtentorial, and suprajugular extensions.

Conclusions:

• The retrosigmoid approach is a versatile technique for posterior skull base surgery.
• Recognizing patient-specific landmark variations allows for tailored surgical planning.
• Personalized surgical strategies can help prevent complications associated with the retrosigmoid approach.