CRANIOTOMY

Prepared By:Gutierrez, Karell Eunice E.BSN3-5 GROUP20

Submitted to:Mrs. Roslyn Mariano RN

CRANIOTOMY

DISCUSSION

The most basic form of craniotomy is the burr hole, a limited opening through which blood or fluid may be evacuated or instruments inserted to divide neural tracts. Additional uses of the burr hole include biopsy of an intracranial mass/lesion and aspiration of the contents of an abscess. A craniectomy refers to the procedure of which a section of the cranium is removed. Trephination refers to a procedure performed through burr holes that are larger than those usually made to performed limited maneuvers. When applicable, a twist drill is used in lieu of a burr. Computed Tomography (CT) scan, magnetic resonance imaging (MRI), angiography or magnetoencephalography, electroencephalogram (EEG) mapping, angiographic stress tests and ultrasound modalities are employed with tomography and three-dimensional (3D) coordinates to localize a lesion. Image guided steriotactic burr hole biopsy, employing a CRW3 (or similar) head frame, provides accurate craniocortical entry transit and targeting minimizing craniocerebral trauma.

Approaches employing endoscopy and stereotactic procedures decrease morbidity and mortality, some cranial procedures performed in specialized readiology departments or specially equipped operating rooms are "same-day" noninvasive procedures, such as those employing the Gamma knife. Intracerebral hematomas can be evacuated endoscopically through a burr hole; the cortical incision is approximately 6mm. In diameter. For removal of an intracranial hematoma, the cortical incision is made from a location with the shortest trajectory to the clot. Endoscopic procedures may require more than one burr (port).

During craniotomy or burr hole procedure, intracranial pressure when elevated is reduced as a result of entry. In addition. As underlying tissued are manipulated, the location of the previously defined lesion shifts. In some institutions, highly sophisticated intraoperative MRI systems are in use. This may be in the form of cylindrical MRI chamber, a section of which can be advanced for imaging and retracted to continue the surgery. When a limited-access endoscopic procedure is not applicable, burr holes are made and a portion (a "flap") of the cranium is lifted. The craniotomy prosthesis can be a plate made of polymethylmethacrylate (PMMA) cement, titanium, or Vitallium, or various plastics may be used for making the substitute Burr holes can be repaired with silicone or other materials.

Numerous neurosurgical conditions treated by craniotomy include the following:

Intracranial Aneurysm is an arterial dilation secondary to muscular weakness prone to rupture or hemorrhage. Controlling the blood pressure is essential during the repair. The aneurysm is isolated, and clips may be applied, or the aneurysm can be coated with PMMA or cyanoacrylate to strengthen the aneurysm wall and provide external support to the blood vessel. When feasible, endovascular approach (via femoral artery) with placement of embolitic materials, like plastic spheres, muscle fragments, or Gugleilmi detachable coils, effectively thrombose the aneurysm; however, collateral channels may develop subsequently, requiring further intervention.

Intracranial Arterial Occlusion may be treated by microsurgical anastomosis; the involved vessel is bypassed distal to the point of obstruction. In this instance, the superficial temporal artery is dissected free for an appropriate distance and passed intracranially through a frontotemporal burr hole incision preparatory to anastomosis.

Intracranial tumors include astrocytoma, glioblastoma multiforme, meningioma, oligodendroglioma, medulloblastoma, lesions of neural; vascular, and connective tissue

origin, and metastases from other sites. The lesions are treated according to their location, size, degree of malignancy, status of the patient. Chordomas, mengiomas, and others may be treated endoscopically. Treatment of acoustic neuroma and tumors about the pituitary are noted below.

Hydrocephalus results from conditions where the flow cerebrospinal fluid is obstructed by ontraventricular lesions or arachnoid or parenchymal cysts, aqueductal or foraminal stenoses, hemorrhages, tumors, and infarction or when there is an overaccumulation of cerebrospinal fluid that collects in the ventricles or the subarachnoid space, causing undue pressure on the brain.

ANATOMY AND PHYSIOLOGY

The Nervous SystemThe nervous system is a network of specialized

cells that communicate information about an animals surroundings and its self, it processes this information and causes reactions in other parts of the body. It is composed of neurons and other specialized cells called glia, that aid in the function of the neurons.

The nervous system is divided broadly into two categories; the peripheral nervous system and the central nervous system. Neurons generate and conduct impulses between and within the two systems. The peripheral nervous system is composed of sensory neurons and the neurons that connect them to the nerve cord, spinal cord and brain, which make up the central nervous system. In response to stimuli, sensory neurons generate and propagate signals to the central nervous system which then process and conduct back signals to the muscles and glands.

The neurons of the nervous systems of animals are interconnected in complex arrangements and use electrochemical signals and neurotransmitters to transmit impulses from one neuron to the next. The interaction of the different neurons form neural circuits that regulate an organism’s perception of the world and what is going on with its body, thus regulating its behavior. Nervous systems are found in many multicellular animals but differ greatly in complexity between species

The central nervous system (CNS) is the largest part of the nervous system, and includes the brain and spinal cord. The spinal cavity holds and protects the spinal cord, while the head contains and protects the brain. The CNS is covered by the meninges, a three layered protective coat. The brain is also protected by the skull, and the spinal cord is also protected by the vertebrae.

Brain is a part of the Central Nervous System, it plays a central role in the control of most bodily functions, including awareness, movements, sensations, thoughts, speech, and memory. Some reflex movements can occur via spinal cord pathways without the participation of brain structures.

The cerebrum is the largest part of the brain and controls voluntary actions, speech, senses, thought, and memory.

The surface of the cerebral cortex has grooves or infoldings (called sulci), the largest of which are termed fissures. Some fissures separate lobes.

The convolutions of the cortex give it a wormy appearance. Each convolution is delimited by two sulci and is also called a gyrus (gyri in plural). The cerebrum is divided into two halves, known as the right and left hemispheres. A mass of fibers called the corpus callosum links the hemispheres. The right hemisphere controls voluntary limb movements on the left side of the body, and the left hemisphere controls voluntary limb movements on the right side of the body. Almost every person has one dominant hemisphere. Each hemisphere is divided into four lobes, or areas, which are interconnected.

The frontal lobes are located in the front of the brain and are responsible for voluntary movement and, via their connections with other lobes, participate in the execution of sequential tasks; speech output; organizational skills; and certain aspects of behavior, mood, and memory.

The parietal lobes are located behind the frontal lobes and in front of the occipital lobes. They process sensory information such as temperature, pain, taste, and touch. In addition, the processing includes information about numbers, attentiveness to the position of one’s body parts, the space around one’s body, and one's relationship to this space.

The temporal lobes are located on each side of the brain. They process memory and auditory (hearing) information and speech and language functions.

The occipital lobes are located at the back of the brain. They receive and process visual information

The Cardiovascular System The heart and circulatory system make up the cardiovascular system. The heart works as

a pump that pushes blood to the organs, tissues, and cells of the body. Blood delivers oxygen and nutrients to every cell and removes the carbon dioxide and waste products made by those cells. Blood is carried from the heart to the rest of the body through a complex network of arteries, arterioles, and capillaries. Blood is returned to the heart through venules and veins.

The one-way circulatory system carries blood to all parts of the body. This process of blood flow within the body is called circulation. Arteries carry oxygen-rich blood away from the heart, and veins carry oxygen-poor blood back to the heart. In pulmonary circulation, though, the roles are switched. It is the pulmonary artery that brings oxygen-poor blood into the lungs and the pulmonary vein that brings oxygen-rich blood back to the heart.

Twenty major arteries make a path through the tissues, where they branch into smaller vessels called arterioles. Arterioles further branch into capillaries, the true deliverers of oxygen and nutrients to the cells. Most capillaries are thinner than a hair. In fact, many are so tiny, only one blood cell can move through them at a time. Once the capillaries deliver oxygen and nutrients and pick up carbon dioxide and other waste, they move the blood back through wider vessels called venules. Venules eventually join to form veins, which deliver the blood back to the heart to pick up oxygen.

Vasoconstriction or the spasm of smooth muscles around the blood vessels causes and decrease in blood flow but an increase in pressure. In vasodilation, the lumen of the blood vessel increase in diameter thereby allowing increase in blood flow. There is no tension on the walls of the vessels therefore, there is lower pressure.

Various external factors also cause changes in blood pressure and pulse rate. An elevation or decline may be detrimental to health. Changes may also be caused or aggravated by other disease conditions existing in other parts of the body.

The blood is part of the circulatory system. Whole blood contains three types of blood cells, including: red blood cells, white blood cells and platelets.

These three types of blood cells are mostly manufactured in the bone marrow of the vertebrae, ribs, pelvis, skull, and sternum. These cells travel through the circulatory system suspended in a yellowish fluid called plasma. Plasma is 90% water and contains nutrients, proteins, hormones, and waste products. Whole blood is a mixture of blood cells and plasma.

Red blood cells (also called erythrocytes) are shaped like slightly indented, flattened disks. Red blood cells contain an iron-rich protein called hemoglobin. Blood gets its bright red color when hemoglobin in red blood cells picks up oxygen in the lungs. As the blood travels through the body, the hemoglobin releases oxygen to the tissues. The body contains more red blood cells than any other type of cell, and each red blood cell has a life span of about 4 months. Each day, the body produces new red blood cells to replace those that die or are lost from the body.

White blood cells (also called leukocytes) are a key part of the body's system for defending itself against infection. They can move in and out of the bloodstream to reach affected tissues. The blood contains far fewer white blood cells than red cells, although the body can increase production of white blood cells to fight infection. There are several types of white blood cells, and their life spans vary from a few days to months. New cells are constantly being formed in the bone marrow.

Several different parts of blood are involved in fighting infection. White blood cells called granulocytes and lymphocytes travel along the walls of blood vessels. They fight bacteria and viruses and may also attempt to destroy cells that have become infected or have changed into cancer cells.

Certain types of white blood cells produce antibodies, special proteins that recognize foreign materials and help the body destroy or neutralize them. When a person has an infection, his or her white cell count often is higher than when he or she is well because more white blood cells are being produced or are entering the bloodstream to battle the infection. After the body has been challenged by some infections, lymphocytes remember how to make the specific antibodies that will quickly attack the same germ if it enters the body again.

Platelets (also called thrombocytes) are tiny oval-shaped cells made in the bone marrow. They help in the clotting process. When a blood vessel breaks, platelets gather in the area and help seal off the leak. Platelets survive only about 9 days in the bloodstream and are constantly being replaced by new cells.

Blood also contains important proteins called clotting factors, which are critical to the clotting process. Although platelets alone can plug small blood vessel leaks and temporarily stop or slow bleeding, the action of clotting factors is needed to produce a strong, stable clot.

Platelets and clotting factors work together to form solid lumps to seal leaks, wounds, cuts, and scratches and to prevent bleeding inside and on the surfaces of our bodies. The process of clotting is like a puzzle with interlocking parts. When the last part is in place, the clot is formed.

When large blood vessels are cut the body may not be able to repair itself through clotting alone. In these cases, dressings or stitches are used to help control bleeding.

In addition to the cells and clotting factors, blood contains other important substances, such as nutrients from the food that has been processed by the digestive system. Blood also carries hormones released by the endocrine glands and carries them to the body parts that need them.

Blood is essential for good health because the body depends on a steady supply of fuel and oxygen to reach its billions of cells. Even the heart couldn't survive without blood flowing through the vessels that bring nourishment to its muscular walls. Blood also carries

carbon dioxide and other waste materials to the lungs, kidneys, and digestive system, from where they are removed from the body.

PREPARATION OF THE PATIENT

Described is a generic-type approach. Planning is essential prior to the surgery. The position of the patient depends on the procedure to be performed, the approach, and the location of the lesion. Equipment for positioning and surgical instrumentation, should be in the room prior to the patients arrival. A warming mattress, Multi-thermia blanket, may be used, or a forced-air warming blanket may be employed. The patient is assisted, as necessary to move from the gurney to the table. When assistance is required, the circulator is responsible for obtaining adequate number of persons to safely transfer the patient from the gurney to the table. Antiembolic hose are applied to the patient's legs to prevent venous stasis. Whn ordered, a sequential compression device with disposable leg wraps may be placed over antiembolic hose. Leads are placed for EEG and electrocardiogram (ECG). An IV and right atrial line may be inserted. All bony preminences and areas vulnerable to skin and neurovascular pressure or trauma are adequately padded.

General anesthesia (with endotracheal intubation) is administered.

POSITIONS

The patient is positioned at the discretion of the anesthesia provider; the patient is never moved without the anesthesia provider's permission. Special frames, positioning aids, padding, headrests, and/or fixation devices are secured to the table to hold the skull in position for the most frequently employed positions; these are mentioned below. The circulator most ensure adequate assistance to position the patient to avoid injury to the patient and the staff.

Supine. An extension may be secured to the table with a headrest device. The skull is fixed in position by steel pins. As the pins are placed in the headrest device, sterility of the pins should be maintained; the pins are inserted into the cranium. Alternatively, the head may be positioned on either a padded donut, or gel-filled horseshoe headrest may be used. The arms may be extended on padded armboards alongside the patient, or the arms may be padded and tucked in at the patients sides. A pillow may be placed behind the lumbar spine or under the knees.

Sitting. In fowler's position, the top section of the table is removed, and a table extension and the headrest are secured to the table to support the patient's head and neck, sterile pins that were placed in the headrest attachment are inserted into the patient's skull. The table is raised from the middle break, and the foot of the table is lowered, the knees are positioned over the lower break of the table. A pillow may be placed behind the legs, and a padded footboard supports the feet. The arms are placed into the patient's lap on a pillow and secured with padded restraints. The safety strap is secured across the thighs. The table may be turned 90 degrees with the anesthesia provider opposite the operative side. Extra caution must be taken to avoid injury to the patient's fingers when the foot of the table is raised at the conclusion of the procedure.

Prone. The patient is intubated on the gurney and, at the discretion of the anesthesia provider, carefully rolled over onto the table. The head may be placed in a padded donut, or more often, the head is placed in a gel-filled horseshoe attachment that replaces the top section of the table. Care is taken to ensure that the patient's eyes are protected from excessive pressure. Chest rolls are placed under the patient's torso, from the acromioclavicular joints to the iliac crests, to facilitate

respiration. The arms may be extended on padded armboards with the forearms pronated, or the arms may be padded and tucked in at the patient's sides. A roll is placed in front of the ankles to protect the toes. Pillows are placed in front of the legs. Padding is placed under the elbows, knees, and other points of contact by bony prominences. Female breasts and male genitals are protected from pressure. The safety strap is secured across the back of the patient's thighs.

Lateral. The patient may be intubated on the gurney and, at the direction of the anesthesia provider, carefully turned to lateral position onto the table, using coordinated teamwork. The torso may be stabilized with padded kidney rests, or a beanbag device that conforms to the patient's body is used. Use of a heating mattress is contraindicated when the beanbag is used, as trapped heat could burn the patient. After checking the chart for patient allergies, the position is stabilized with wide adhesive tape or a folded towel or a blanket may be placed under the tape. A mayo stand, padded with a pillow, supports the uppermost arm, or a padded double armboard may be used.The leg on the dependent side is flexed;the upper leg may be straight or slightly flexed(to stabilize the position)with a pillow placed between the legs; padding, foam, or gel pads are placed around the feets and ankles.

Skin Preparation

Most surgeons prefer to cut the hair and shave the scalp. Check with the surgeons regarding the area to be prepped and the solution to be used for the skin prep (by the circulator). Antibiotic ointment (e.g., Polysporin) may be put in the eyes, and and eye pads and nonirritating tape may be used to tape lids shut; plastic eye shields are helpful to avoid undue pressure on the eyes. Care is taken to avoid getting prep solution in the eyes. Small cotton pledgets or cotton balls are placed in the ears (some surgeons prefer removing them with a mosquito forceps before draping). To avoid a fire hazard, prep solutions are not allowed to pool on the drapes. The surgeon usually marks the line of incision before draping. The prepped area must be carefully dried; otherwise, the plastic drape will not stick. Use aterile technique when removing the towel. If a bone grafting is anticipated, the bone graft area is prepped and draped at the same time.

Draping

Surgeons usually prefer to do the draping. Folded towels are placed around the operative site and secured by towel clips, staples, or sutures; the scrub person prepares ahead heavy silk sutures(e.g.,#2) on cutting needles, two needle holders, toothed forceps, and suture scissors. A large drape sheet is placed below the head. A craniotomy sheet with an adhesive plastic backing in the fenestration is used, or a sterile, plastic adhesive drape is placed, followed by a drape sheet under the head, and a sheet with an aperture sized for craniotomy exposure is used. The prepped area must be dry, or the adhesive drape will not stick. An impervious drape (e.g., plastic) with a collection pouch is usually preferred. If an overhead table (e.g., Mayfield)is used, a large drape sheet, fanfolded at the front edge of the table, is used. The fanfolded sheet is brought down to close off the space between the unsterile area under the table and the operative field. The disposable craniotomy sheet will eliminate the need for additional drape sheets; otherwise, a fenestrated sheet and drape sheets, as necessary, are placed to avoid contamination. Additional draping may be required for the microsope, C-arm, stand, drills and saws, and table with the andoscopes etc. For iliac bone graft, add: towels, sterile, plastic adhesive drape, a drape sheet with a medium-sized fenestration, and a towel or sheet to cover the graft site until exposure is necessary.

NURSING CONSIDERATIONS

Preoperative Medical and Nursing Management.

(1) Instruct patient and family about the necessity and importance of diagnostic tests to determine the exact location of the tumor.(2) Monitor and record vital signs and neurological status accurately q2-4h, or as ordered. Report changes to professional nurse immediately.(3) Institute measures to prevent inadvertent increases in intracranial pressure.

(a) Elevate head of bed 30º.(b) Stool softeners to prevent straining at stool (which increases intracranial pressure).

(4) Institute seizure precautions at patient's bedside. (Tongue blade airway.)(5) Supportive nursing care is given depending upon the patient's symptoms and ability to perform activities of daily living.(6) Administer all doses of steroids and antiepileptic agents on time.

(a) Withholding steroids can result in adrenal crisis.(b) Withholding of antiepileptic agents frequently precipitates seizure.

(7) Surgery (craniotomy) is performed to remove neoplasm and alleviate symptoms.

Post Operative Nursing Care Considerations

(1) Meticulous nursing management and care aimed at prevention of postoperative complications are imperative for the patient's survival.(2) Accurately monitor and record all vital signs and neurological signs.

(a) Postoperative cerebral edema peaks between 48 and 60 hours following surgery.(b) Patient may be lucid during first 24 hours, then experience a decrease in level of consciousness during this time.

(3) Administer artificial tears (eye drops) as ordered, to prevent corneal ulceration in the comatose patient.(4) Maintain skin integrity.(5) Bone flap may not have been replaced over surgical site; turning patient to the affected side, if the flap has been removed, can cause irreversible damage in the first 72 hours.(6) Maintain head of bed at 30ºelevation.(7) Perform passive range of motion exercises to all extremities every 2-4 hours.(8) Maintain body temperature.

(a) Increases of body temperature in the neurosurgical patient may be due to cerebral edema around the hypothalamus.(b) Monitor rectal temperature frequently.(c) Place patient on hypothermia blanket, as ordered.

(9) Institute seizure precautions at patient's bedside. (Tongue blade, airway.)(10) Maintain accurate record of intake and output. (11) Prevent pulmonary complications associated with bedrest.

(a) Cough and deep breath every 2 hours.(b) Perform gentle chest percussion, with the patient in the lateral decubitus position, if tolerated.

(12) Continuously talk to the patient while providing care, reorienting him to person, place, and time.

INSTRUMENTATION

Craniotomy Surgical Set

2Jansen Retractor

2Weitlaner Retractor

1Scalpel Handle #3

1Scalpel Handle #4

1Scalpel Handle #7

4Solid Bar Handle For Gigli Saw

2Adson (Ewald) Dressing Forceps

2Adson Tissue Forceps

12Backhaus Towel Clamp

2Cushing Brain Forceps

2Cushing Brain Forceps

1Echlin Rongeur

6Foerster Sponge Forceps

6Foerster Sponge Forceps

18Halsted Mosquito Forceps

18Halsted Mosquito Forceps

1Luer Bone Rongeur

1Stille-Liston Rongeur

2Mayo-Hegar Needle Holder

1Gigli Saw Wire

1Gigli Saw Wire

1Operating Scissors

1Mayo-Stille Dissecting Scissors

1Mayo-Stille Dissecting Scissors

1Metzenbaum Dissecting Scissors

1Taylor Dural Scissors

Jansen Retractor

Weitlaner retractor

Scalpel

Adson (Ewald) Dressing Forceps

Adson Tissue Forceps

Backhaus Towel Clamp

Cushing Brain Forceps (Delicate Serrated)

Echlin Rongeur

Foerster Sponge Forceps

Halsted Mosquito Forceps

Halsted Mosquito Forceps

Luer Bone Rongeur

stille-Liston Rongeur

Mayo-Hegar Needle Holder

Gigli Saw Wire

Operating Scissors

Mayo-Stille Dissecting Scissors

Mayo-Stille Dissecting Scissors curved

Taylor Dural Scissors