1. Basic surgical approaches to intracranial space

What are the 5 approaches?

1. Trepanation 2. Craniotomy 3. Craniectomy 4. Cranioplasty 5. Dural suture

Difference between craniotomy and craniectomy?

A Craniectomy is similar to a craniotomy as both procedures involve removing a portion of the skull, the difference is that after a craniotomy the bone is replaced and after a craniectomy the bone is not immediately replaced.

What is a craniectomy?

A craniectomy is a type of surgery to remove a portion of your skull. This helps relieve extra pressure on your brain. - Usually the first part of further brain surgery - The bone flap is temporarily removed - It is later returned to the skull after surgery

Infratentorial craniotomy

A surgical procedure to remove a brain tumor located in either the infratentorial or posterior fossa regions of the brain. Suboccipital craniotomy: Nowadays, the most common workhorse approaches to the posterior fossa include the midline suboccipital and the lateral suboccipital (retromastoid) approaches. The most common indications for midline suboccipital craniotomy are: developmental anomalies such as Chiari malformations, posterior fossa tumors such as metastatic tumors, meningiomas, ependymomas, astrocytomas, and medulloblastomas, vascular lesions such as aneurysms, cavernous malformations, and arteriovenous malformations, and pineal region tumors accessed through the supracerebellar corridor. Retrosigmoid craniotomy: Retro-sigmoid craniotomy (often called "keyhole" craniotomy) is a minimally-invasive surgical procedure performed to remove brain tumors. This procedure allows for the removal of skull base tumors through a small incision behind the ear, providing access to the cerebellum and brainstem.

What is a craniotomy?

An operation where a small hole is made in the skull or a piece of bone from the skull is removed to show part of the brain. Osteoplastic: Flap is attached to the surrounding muscle. Free flap: Not attached A craniotomy may be done to remove a brain tumor or a sample of brain tissue. It may also be done to remove blood or blood clots from the brain, relieve pressure in the brain after an injury or stroke, repair a skull fracture or brain aneurysm (a bulge in a blood vessel wall), or treat other brain conditions. The piece of bone that is removed from the skull is usually put back in place after the surgery has been done.

General complications of these procedures?

Bleeding, infection, blood clots, and reaction to anesthesia. Special complication related to craniotomy may include: stroke, seizures, dwelling of the brain, nerve damage, cerebrospinal fluid leakage, or loss of some mental functions.

What is a cranioplasty?

Cranioplasty, the repair of a skull vault defect by insertion of an object (bone or nonbiological materials such as metal or plastic plates), is a well-known procedure in modern neurosurgery. Brain protection and cosmetic aspects are the major indications of cranioplasty

What is the intracranial space?

The cranial cavity also known as intracranial space is the space within the skull that accommodates the brain.

What is trepanation?

Less invasive. A surgical intervention in which a hole is drilled or scraped into the human skull. Not used in neurosurgery now, instead we use craniotomy. Used before to remove fluid or release pressure. Used before in epidural and subdural hematomas.

What is dural suture?

Microsurgical: uses microscope and fine needle.

Supratentorial craniotomy

Supratentorial craniotomy means the exposure of any part of a cerebral hemisphere over the basal line joining the nasion to the inion. Supratentorial craniotomy is divided into: Frontal: The frontal craniotomy is used to access the frontal skull base and the frontal lobe of the brain for approaches to the third ventricle or sellar region tumors, craniopharyngiomas, planum sphenoidale meningiomas, frontal lobe tumors, and repair of anterior cerebrospinal fluid fistulas Parietal: Parietal craniotomy is designed to provide an operative exposure of the mid to posterior hemisphere while sparing the highly functional anteriorly located sensorimotor cortices and the posteriorly located visual cortex. The parietal craniotomy is used for both intra- and extra-axial lesions of the region, including neoplasms such as metastases, gliomas, and meningiomas, and vascular lesions such as arteriovenous malformations and cavernous malformations. The parietal interhemispheric corridor is used to approach parafalcine, medial parietal, and splenial lesions. Temporal: Temporal craniotomy is a simple approach that has vast applicability to intra-axial and extra-axial pathologies. The subtemporal approach provides a wide operative corridor to the floor of the middle fossa and upper petroclival territories and their associated cisterns. More specifically, this corridor reaches the anterior upper brainstem through the anterior petrosectomy. Temporal craniotomy is beneficial for resection of mid to posterior intraparenchymal and convexity temporal lobe tumors. This route also affords access to mid hippocampal lesions through the transsulcal approach and reaches lateral thalamic tumors and basal cisterns through the transcortical transventricular transchoroidal pathway. The exposure of the Sylvian fissure is limited. Occipital: The occipital craniotomy is designed to provide operative exposure of the occipital lobe, tentorium and posterior incisural space, splenium of the corpus callosum, medial and posterior temporal lobe, posterior thalamus, atrium of the lateral ventricle, and parieto-occipital area. An occipital craniotomy is commonly used for both intra- and extraaxial lesions of the region, including neoplasms such as metastases, gliomas, and tentorial meningiomas, and vascular lesions such as arteriovenous and cavernous malformations. Pterional: The pterional or frontotemporal craniotomy is the workhorse of the supratentorial approaches. Because of its simplicity, flexibility, efficiency, and familiarity to neurosurgeons, this corridor is the most commonly used surgical route to lesions along the anterior and middle skull base. Bifrontal: Pathologies that are positioned on one or both side(s) of the falx along the anterior fossa can be reached surgically through either the unilateral anterior parasagittal route or a combination of the supraorbital, pterional, and orbitozygomatic approaches.I use a bifrontal craniotomy only for large tumors that have anterior skull base invasion.