====== Dural Dissection ======

'''Dural dissection''' refers to the surgical technique of incising and separating the layers of the dura mater to expose underlying neural or vascular structures.

=== Definition ===
**Dural dissection** is the controlled separation or incision of the dura mater, the outermost meningeal layer, often required in neurosurgical procedures for access to the brain, spinal cord, or dural-based lesions.

=== Anatomical Context ===
  * The **dura mater** consists of two layers:
    - **Periosteal layer** (outer): adheres to the skull.
    - **Meningeal layer** (inner): continues into the spinal canal.
  * In the spine, the dura is a single layer.

=== Surgical Applications ===
  * **Craniotomy**: Opening of the dura to access the cortex or deeper structures.
  * **Spine surgery**: Dural opening to access the spinal cord or intradural lesions.
  * **Dural-based tumors**: e.g., meningiomas, where dural dissection helps define margins or perform resection.
  * **Bypass and aneurysm surgery**: Dissection around dural folds (e.g., tentorium, falx).

=== Techniques ===
  * Performed under magnification (microscope or loupe).
  * Linear, curvilinear, or stellate incisions using micro scissors or scalpel.
  * Edge of dura often reflected and secured with tack-up sutures to reduce epidural bleeding.
  * Dural closure with watertight sutures or dural substitutes to prevent CSF leak.

=== Risks ===
  * **Cerebrospinal fluid (CSF) leak**
  * **Dural venous sinus injury**
  * **Postoperative pseudomeningocele or meningitis** if not properly closed

=== Notes ===
  * In some cases (e.g., Chiari malformation surgery), duraplasty is performed after dural dissection to enlarge the dural space.
  * Dural dissection can be technically challenging near adhesions, scar tissue, or vascular structures.