Overview
This lecture covers the pterional approach in neurosurgery, detailing its indications, surgical steps, anatomical considerations, and modifications to maximize exposure while minimizing brain retraction.
Pterional Approach Overview
- The pterional approach is a widely used neurosurgical technique for various pathologies, such as aneurysms and tumors.
- It provides access to lesions in regions like the cavernous, temporal, frontal lobes, and more.
- The main limitation is the small surgical corridor, which can make manipulation challenging.
Surgical Technique & Key Steps
- The skin flap is typically a single-layer incision made just anterior to the ear, curving above the hairline for better cosmetics.
- The temporal artery branch is preserved for possible bypass use.
- The incision extends through all layers to the bone, with the temporalis fascia incised as well.
- For the orbitozygomatic approach, dissection occurs between fascial layers to protect the facial nerve.
- Bone flap creation starts with a burr hole and careful drilling to avoid damaging underlying structures.
- Mastery of the surgical drill, including using cutting and diamond burrs, is essential for safe and effective exposure.
- The sphenoid ridge is flattened to maximize basal exposure and minimize brain retraction.
Dura Opening & Brain Relaxation
- Classic dura openings include a C-shaped or L-shaped incision, depending on the surgical target.
- Proper understanding of cisternal anatomy is necessary for safely releasing cerebrospinal fluid (CSF) and relaxing the brain.
- Utilizing gravity and patient positioning helps reduce the need for brain retraction.
Closure & Modifications
- The dura is closed in a watertight fashion, and the bone flap is secured with minimal gaps.
- Drainage may be applied, though it's not always necessary.
- Various modifications exist, such as mini-pterional, frontotemporal, or orbitozygomatic approaches, to tailor exposure to the lesion.
Key Terms & Definitions
- Pterional Approach — A neurosurgical craniotomy technique providing access to key anterior cranial fossa structures.
- Burr Hole — An opening drilled into the skull to start the craniotomy.
- Temporalis Fascia — The connective tissue covering the temporalis muscle, incised during approach.
- Orbitozygomatic Approach — An extended version of the pterional craniotomy involving the orbit and zygomatic arch.
- Cisternal Anatomy — The study of fluid-filled spaces in the brain, important for safe CSF release.
Action Items / Next Steps
- Practice drilling techniques and anatomy in the lab to build confidence and safety skills.
- Review cisternal anatomy and practice dura opening techniques.
- Explore variations of the pterional approach for different pathologies.