Chapter 24: Neurosurgery; Short Answer: Cranial Surgery; Spinal Procedures

Hydrocephalus has several causes. Identify three.

1) Obstructive: increase in CSF 2) Infant: enlarged head circumference 3) Childhood: meningitis Adults: 1) obstructive tumors, 2) meningitis, 3) hemorrhage

What is the ideal temperature for irrigation fluid that will be used within the cranium?

Body temperature saline.

How is bleeding controlled during the craniotomy?

Bone wax and neurosurgical sponges.

What is used for hemostasis during the procedure?

Bone wax, bipolar forceps, and thrombin-soaked gelfoam.

What is used to retract or provide visualization during the procedure?

Brain spoons/spatulas; manually or attached to the Leyla-Yasargil self-retaining retractor. The microscope may be needed for visualization.

What surgical procedure is completed to relieve pressure on the median nerve?

Carpal tunnel release.

What is the CUSA, and how is it used?

Cavitron Ultrasonic Aspirator; emits a variable ultrasonic energy field that emulsifies abnormal tissue while preserving normal neural tissue. Saline ejected from the tip of the handheld unit liquefies the tissue, which is then aspirated back to the unit. This instrument is used when a moderate to large amount of tissue is to be removed.

What supplies may be necessary to remove scalp hair in the operating room?

Clippers, blades, drape, anesthetic or microbial agent, and towels.

What are the most common reasons for neurosurgery?

Congenital defects, traumatic injury, degeneration, cancer.

How is the dura lifted free from the brain tissue? What is used to protect brain tissue during the procedure?

Cottonoids are placed under the dura with bayonet forceps as the dura is incised to protect the brain tissue. 4-0 dural traction sutures are placed along the dural edges and tagged with mosquito hemostats for retraction.

What is the most common approach for a pituitary tumor? Where can the incision be made?

Craniotomy or transsphenoidal resection. The incision is made through the sella turcica through the sphenoid sinus.

What is a discectomy?

Decompression of a nerve root that has been impinged by an extruded fragment of disc material in the cervical, thoracic, or lumbar region of the spine.

What is a laminectomy?

Decompression of an injured spinal disc. Removal of the anterior cervical disk and the excision and placement of a bone graft.

Why is a thoracotomy approach more popular for thoracic vertebral surgery?

Due to the small diameter of the thoracic spinal canal.

What is a spinal fusion? How is it done?

Fixation of an unstable segment of the spine. Involves the stabilization of a spinal section with a bone graft or synthetic device, introduced through a posterior incision in the lumbar region

What is the most common type of brain tumor?

Gliomas; Glioblastoma multiforme (GBM)

When enlarging the holes drilled or removing bone, what is used to accomplish the process? What should the ST do as the pieces are removed?

Holes are enlarged with a double-action rongeur or a kerrison. Bone wax may be pressed against the tip of a #4 penfield dissector and passed to the surgeon.

What is ICP? What procedure is completed to place an ICP monitor?

Intracranial pressure burr hole. An intraventricular catheter did the most accurate method.

What is done to counteract friction, remove bone dust, and eliminate heat during the process of drilling bone?

Irrigate drill bit while in motion with saline to counteract heat generated by friction and to remove bone dust.

What symptoms are associated with acoustic neuromas? Which nerve is affected?

Loss of hearing, headache, vertigo, and facial pain.

Compare the open procedure with the microdecompression endoscopic shunt discectomy; what are the primary differences?

Microdecompression endoscopic spinal discectomy, x-rays, fluoroscopy, and endoscopic instruments the disc is removed and/or shrunk with the use of a laser.

What is done with the bone flap during the procedure?

Placed in a labeled basin on the back table to soak in betadine or normal saline and antibiotics.

What is a rhizotomy and why would we perform it?

Procedure to sever roots in the spinal cord. Preformed to effectively relieve chronic back pain.

if instrumentation is to be placed for any surgical spine procedure, what patient position is most likely?

Prone position.

How do Raney clips differ from Aneurysm clips?

Raney clips: Used on the scalp edges as the primary incision is made for a craniotomy. Provides pressure for hemostasis. Aneurysm clips: Used for clamping off an aneurysm. Clips should be made of compatible materials. ONCE THE JAWS ARE OPENED, DO NOT REUSE!

What is the difference between a subdural hematoma and an epidural hematoma?

Subdural: Occurs in relation to severe head injuries, arachnoid and dura mater. Epidural: May result from a fractured skull, dura mater and skull.

Describe how the cranial bone flap is closed.

The brain is irrigated with copious amounts of body temperature saline and antibiotics, the dura is closed in an airtight fashion with a running 4-0 braided nylon or silk suture. The flap is then placed and screwed on with plates and screws.

Access to the occipital lobe of the brain may be accomplished with the patient in either of two positions. Name the two possible positions.

The lateral or semi-lateral position is used for exposure of the occipital lobe. Prone or sitting position.

What is used to remove the pituitary tumor? What is used to replace that tissue?

The tumor is removed with pituitary curette, dissector, enucleator, and suction. A fascial graft from the thigh and kept in saline.

Describe the funny bone. If the patient presents with pain in the ring and small finger of the affected hand with weakness, what is the probable diagnosis? What procedure(s) is (are) completed to relieve the symptoms?

The ulnar nerve travels through a tunnel of tissue (cubital) that runs under the medial epicondyle of the elbow. Diagnosis: Median nerve compressed. Ulnar nerve transposition is the procedure to relieve these symptoms.

What is the Mayfield pin-fixation device used to accomplish?

Used as a horseshoe headrest for the cervical spine. It supports the patient's head and ensures the patient lies perfectly still.

How is the dura separated from the bone flap?

AA #3 penfield to prevent tearing of the dura mater when the flap is turned. The craniotomy is irrigated with saline.

Compare ACDF and PCDF; what are the essential differences?

ACDF: Anterior cervical discectomy and fusion PCDF: Posterior cervical decompression and fusion

What can be used to create the burr holes for the craniotomy or provide relief of intracranial pressure? If you are doing a craniotomy, how is the bone flap created?

An air-powered burr or an electric, battery powered cranial perforator. Occasionally burr holes are drilled manually with a Hudson brace and D'Errico bit.