Brain Surgery Information:

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CHAPTER 12: THE OPEN SURGICAL PROCEDURE AND EARLY POSTOPERATIVE PERIOD (including craniotomy images)

Most brain surgeries take about 3-5 hours of operating time. However, by the time a patient has been called down to surgery, administered general anesthesia, operated on, woken up following surgery, observed in the postoperative recovery area, and then transferred to the ICU, many more hours may pass. It is normal for family members to be anxious during times of surgery on a loved one, and there is generally a waiting area in the ICU or near the operating room (OR) complex to which family members will be directed. If family members leave that area, they should leave a contact number with the staff there so that they can be reached, even if only for an update regarding how the surgery is proceeding. Not all institutions have “Communicators” who provide periodic updates during the surgery. Also, it is important to note that some brain surgeries may take longer owing to the complexity of the lesion or if there is more than one lesion being treated. This is generally discussed by the neurosurgeon prior to elective surgery. A neurosurgeon will take “as long as it takes” to carry out the surgery as skillfully and as safely as possible. The neurosurgeon, or a member of the operating team, should come and personally speak to the family at the conclusion of surgery to inform them regarding how things went and what to expect in the short term. For any concerns, family members should feel free to check with the desk staff.

Elective brain surgery typically involves the patient being brought to the OR awake and oriented, followed by the placement of one or more IV lines if this had not already taken place in the preoperative or “holding” area. After the lines are placed, the patient breathes oxygen and anesthetic gases, is given IV sedation and, in this manner, is safely and comfortably put to sleep and intubated. Intubation involves placement of a breathing tube usually through the mouth and into the trachea for controlled ventilation during the procedure as the patient will be under deep anesthesia. A tube placed in this manner is referred to as an endotracheal (ET) tube. After this time, other lines are placed by the anesthesia team, such as an intraarterial line in the wrist artery for continuous blood pressure monitoring during the case, and possibly a deep IV line in the neck or upper chest called a “central line” for invasive monitoring of the patient’s cardiovascular system. Thereafter, the neurosurgical team gets involved. The head is appropriately positioned for the surgery, and the body is well padded and secured to the OR table. The head is usually held in place during the surgery by a pinion, which is a metal clamp that has three points that enter into the skin of the scalp and are pressure-adjusted to make contact with the outer skull bone (Figure 15). The pinion, which keeps the head very still during surgery, is removed at the end of the procedure. The three pin holes are frequently filled with an antibiotic ointment after the pinion is removed, and the holes seal up on their own within 24 hours of surgery for the vast majority of patients. The pin sites typically pose no significant infection or cosmetic risk. They are very small and usually behind the hairline, although there may be one somewhere in the forehead which should also heal well.

Figure 15 (above). Pinion.

After the patient is positioned, the scalp hair is shaved. The degree of the head shave varies from surgeon to surgeon. Many surgeons now prefer a relatively minimal head shave, namely, a 1-2 cm or half-of-one-inch wide strip of hair shaved in the appropriate location, typically behind the natural hairline (Figure 16). This is cosmetically appealing to most patients compared with a more extensive head shave, and there appears to be no proven downside to this, including no evidence of any increased infection if the usual “aseptic” measures are adhered to. Once the field is prepared with the appropriate antiseptic solutions and draped in a sterile manner, the OR scrub staff prepare the equipment around the field, and the surgery commences. The incision is made with a scalpel, and a scalp flap is turned and reflected to give good exposure of the cranial or skull bone and therefore the “craniotomy site”. This site varies depending on the lesion, but most frequently involves the front and side of the head for frontotemporal and “pterional” craniotomies. There may be additional removal, followed by replacement at the end of the procedure, of the bones around the eye and/or cheek region as part of an “orbitozygomatic” (OZ) approach. Other frequent types of craniotomy for a lesion located at the back and under part of the brain near the brainstem, are those referred to as suboccipital and retrosigmoid craniotomies. The incision for the “frontotemporal crani” or one its variants goes from just in front of the ear, proceeds upwards and just behind the forehead hairline, and may swing slightly across the midline to the other side just behind the hairline (Figure 16). The incisions for the “suboccipital crani” and “retrosigmoid crani” are curved or linear ones located somewhere at the back of the head, depending on the location of the lesion (Figure 17). Other specific craniotomies have incisions located differently.

Figure 16 (above). Minimal head shave and frontotemporal and pterional craniotomy incisions.

Figure 17 (above). Suboccipital and retrosigmoid craniotomy incisions.

After the scalp flap is turned, the exposed bone flap is removed using a high speed drill. Small “burr” holes are made in the skull and, with an appropriate attachment to seat the drill, the bone flap is removed (Figure 18). The dura is then exposed (Figure 19) and opened sharply with a scalpel and dural scissors. Once the dura is reflected out of the way, the brain surface is now seen (Figure 20).

Figure 18 (above). Scalp flap turned, cranium exposed, burr holes being drilled.

Figure 19 (above). Bone flap removed and dura exposed.

Figure 20 (above). Dura opened and reflected, and brain surface exposed.

The operating microscope is brought into the field. The neurosurgeon then proceeds meticulously defining the nerve and vessel or neurovascular structures leading to and neighboring the brain lesion. The surgeon has available a wide variety of “microinstruments” to help in the dissection and removal or resection of the lesion, or its clipping if the lesion happens to be a brain aneurysm. At the conclusion of the procedure, when the field is dry, the dura is most often reapproximated with sutures. The bone flap is then replaced, typically affixed with titanium miniplates and screws (Figure 21). It is restored so that a good cosmetic and structural result is obtained. The scalp is then closed with multiple layers of buried suture and either sutures or staples are used for the skin closure.

Figure 21 (above). Bone flap restored with titanium miniplates and screws.

Postoperatively, the patient will be transferred to the ICU. This is a fairly busy environment. Most have waiting areas for family members. Most have numerous medical and paramedical staff members. The rooms vary, some are one-patient only rooms, others accommodate two or more patients. There are many gadgets in each ICU room, with lots of lighted displays and sounds. Patients and family members should not be alarmed by these. The most obvious may be the monitor which displays the vital signs such as heart and breathing rate and rhythm, blood pressure, blood oxygen level, and so forth. There will be an IV line stand which holds the main IV fluid, and pain and other IV medications and, for some patients, a ventilator machine for the breathing tube. There may also be thin plastic drainage tubing coming from the patient’s head or back to a nearby stand as part of the EVD or lumbar drain system (Chapter 13). The patient may have a head wrap on, which is like a white gauze turban with or without a fishnet outer wrap. In other words, a bandage that applies pressure around the head incision. There may be drainage tubing coming from this wrap, for a drain left under the scalp to drain blood that can accumulate underneath the incision edges. If the wrap and drain are present, they are generally removed the day after surgery. Some surgeons leave no head wrap, while others leave a head wrap on for 24-48 hours. The practice varies based on the surgeon’s preference.

If a patient has returned to the ICU without an ET tube in, it means the anesthesiologist felt that the patient had met all requirements for extubation, that is, removal of the breathing tube following surgery. The patient therefore probably demonstrated to the anesthesia doctor at the end of surgery that he or she was able to follow commands by appropriately squeezing hands and wiggling toes, and was awake and strong enough to manage his or her own airway without further need for a tube. Note that a breathing tube causes some degree of throat irritation, and a patient may cough or spit up some blood-tinged saliva for the first few days after extubation. The patient may also have a dry or sore throat during this period, usually well treated with humidified air and throat lozenges. Such patients will usually be lucid or awake enough to talk and interact relatively well within a few hours of surgery. They still may be drowsy and in some pain. The drowsiness usually subsides on its own accord after the first night. The head pain subsides with appropriate pain medication. If the patient seems to be in pain that is not being appropriately controlled, the nursing and medical staff will alter the medications appropriately or ask for a “Pain Service” specialist to assist in the treatment. The vast majority of patients undergoing brain surgery do not experience significant incisional or operative pain after the first few days following the operation. However, they do experience some pain for the first 7-10 days after surgery, and usually this is well controlled with IV followed by oral narcotic medications over this period. The patient is asked to wean themselves off oral pain medications by 7-14 days as the pain gradually disappears.

The ICU staff doctors include a neurologist and/or an anesthesiologist with a special interest in critical care, and a neurosurgeon or neurosurgical resident or registrar. These doctors will regularly check on their ICU patients who will also be under the close supervision of the ICU nursing staff. The nursing staff will carry out and chart the regular neurological and vital observations of the patient, in addition to other “routine” but very important care of the patient including IV pain medication and fluid administration, patient positioning, pill and food administration and hygiene. Nurses will let the doctors know if there is any significant neurological change in the patient’s state. Other paramedical staff may attend to ventilator management, urinary catheter management, and so forth, if the patient is still dependent on such equipment. The doctors and nurses generally make every attempt to update families daily. Note that at most centers, doctors round on their ICU patients at least twice daily. If patients or family members feel that there is not enough reasonable communication updating them or addressing their concerns, they should discuss this with the nursing or medical staff, or the ICU’s nurse-manager.

If a patient returns to the ICU with an ET tube, the reasons may be multiple. It may be that the patient was in a poor neurological condition going into surgery. In such cases, the recovery will also be expected to be slow, and such patients may need more time before they are alert and strong enough to be safely extubated. Alternatively, the surgery may have been expectedly or unexpectedly complex, in which case the surgeon and anesthesiologist may favor keeping the patient intubated for the first night or so after surgery. Additionally, in surgery involving lesions near the brain stem, safe extubation may be hampered by swelling or damage of the lower brain stem pathways and nerves, some of which are very closely involved with respiration, speech and swallowing. For such patients, a longer period of intubation may be recommended or required to assist their breathing, and to prevent them from inhaling swallowed substances including saliva into their lungs, referred to as aspiration. The doctors should provide information regarding these matters and their reasoning for prolonged intubation (Chapter 17). Overall, the vast majority of brain surgery patients are successfully extubated at the conclusion of surgery.

Although events during the early postoperative period, that is, within the first 24-72 hours following surgery, vary according to the patient’s neurological condition prior to surgery and the type of surgery, most elective neurosurgery patients are awake and talking on the night of the surgery, though they still may be drowsy. Most spend the first night in bed rest, with a Foley or urinary catheter and IV fluids and medications to help them along. Over the next day or two, many of these patients are encouraged to be sitting out of bed, and to begin eating. The earlier one is out of bed, the better it is for one’s lungs which otherwise experience some degree of collapse and congestion in patients who for whatever reason are immobile or nonambulatory. Being ambulatory is also very helpful for the circulation, helping to prevent blood clots in the legs and lungs. In the day or few days after surgery, most neurosurgery patients should be expected to be walking again. Most will move from the ICU to a regular ward or “floor” bed after one or two nights, and many are dismissed from hospital after 3 or 4 nights. Many do not require any specific physical therapy (PT), but are rather encouraged to walk as much as possible. Climbing stairs is encouraged, as are eating a nutritious, well-balanced diet and gradually resuming regular activities including driving, sex, physical exercise, and work when their bodies tell them they are ready. Hospital dismissal criteria for elective neurosurgery patients include being able to safely and independently walk, eat and excrete, in addition to having minimal, or at least well controlled, pain and a clean, dry and intact incision. At the time of a patient’s dismissal, the medical team should provide the patient with a written summary of his or her stay and operation, and a telephone number for the patient to call if any neurological or wound or other concerns develop. The patient and family should be sure to have such contact details before leaving the hospital. Regarding the postoperative followup visit, a patient should check with the neurosurgeon or medical team regarding this. Many centers will automatically mail this appointment to the patient. The timing of the visit varies from patient to patient and from surgeon to surgeon. It cannot be overstated that appropriate followup for brain surgery patients is essential. Also, if a patient has staples or sutures in the incision at the time of dismissal, which is generally the case, someone needs to check on and remove them at the appropriate time, usually around 10-12 days after surgery. This is referred to as a wound check. The patient’s local doctor or nurse can remove these. Suture or staple removal is not a painful procedure. There may be slight tugging, but there should be no significant discomfort. Alternatively, the patient’s surgeon or his or her assistant can remove these per the arrangements made at dismissal. In general, it takes anywhere between 3-12 weeks from the date of elective brain surgery for a patient to feel that he or she has significantly recovered to be able to resume a relatively normal life again.

The early postoperative period for a neurosurgery patient operated on emergently, that is, under emergency or life-threatening conditions, may be different to the above. It heavily depends on the patient’s neurological condition at the time of the hospital admission. First, such a patient may require more prolonged intubation or a more prolonged ICU stay. Second, such patients frequently take longer to mobilize as their brains have to heal from, say, blood being where it shouldn’t be, or from herniation or other brain injury associated with their condition. As a result, they may take a few or several days, or even much longer, to be in a position to be safely moved out of bed, to finally walk, and be disconnected from all their drips, lines and tubes. They may have an EVD or lumbar drain, and require monitoring and treatment for the development of complications. A Physical Medicine and Rehabilitation (PMR) Service (Chapter 20) may be consulted to help in meeting the physical needs of such patients, with an aim to optimizing their overall recovery. There may be a need for only brief bedside PT. Alternatively, at some point during the hospital stay of an emergently treated neurosurgery patient, or an elective neurosurgery patient in whom a complication has arisen, it may be recommended that the patient undergo inpatient rehabilitation to further maximize the chance of an acceptable physical recovery (Chapter 20).

Finally, some words regarding endoscopic brain surgery or neuroendoscopy. Neurosurgery through an endoscope, which is a thin, tube-like telescope, is a form of minimally invasive surgery (MIS), or “keyhole” surgery. This means there is only a tiny skin incision, a small opening or burr hole or keyhole in the skull bone, and the procedure may be shorter in duration than for open surgery (Figure 22).

Figure 22. Keyhole or minimally invasive surgery: Neuroendoscopy.

MIS in the brain is carried out mainly for two reasons or “indications”: (1) Tumors situated in the ventricles; and (2) CSF diversion in certain patients with obstruction of CSF drainage at the back of the brain’s ventricular system, near a structure called the cerebral aqueduct. The former indication is referred to as an intraventricular tumor, the latter as an endoscopic third ventriculostomy (ETV). For intraventricular tumors, the thin tubular endoscope is carefully advanced through the brain and into the ventricles. The neurosurgeon can watch the procedure in real-time on a television monitor because the endoscope has a light source and camera. The neurosurgeon maneuvers the endoscope through the ventricular system to the tumor, and using fine instruments deployed through the tube, can biopsy or remove the tumor in pieces. Sometimes there can be bleeding, and an EVD may need to be left to clear the CSF of blood after the procedure (Chapter 13). During an ETV, the endoscope is used to create a small hole in the floor of one of the ventricles known as the third ventricle. By doing so, CSF can be diverted by an alternative pathway, somewhat akin to an internal shunting procedure, except there is no tubing left behind. An ETV can not be carried out for all patients, and in some for whom it is carried out, the opening may close off, thereby requiring an actual shunt to be placed (Chapter 13). MIS is of course not without risk, but the risks are usually low (Chapter 18). The patient is asleep for the procedure, and many of the preoperative and postoperative issues mentioned earlier apply to MIS patients as well.

Craniotomy Sequence Images*:

Craniotomy sequence - Image 1 (above left): A small but symptomatic frontal lobe arteriovenous malformation (AVM) in a young patient is shown here on an MRI scan.

Craniotomy sequence - Image 2 (above right): With the patient asleep under general anesthesia, a scalp incision is made and the scalp flaps temporarily retracted to expose the underlying bone. The skull bone (cranium) immediately overlying the AVM has been marked following mapping of the AVM's size and certain features using neuronavigation information (see below). A burr hole is drilled, and a high-speed microdrill is then used to remove the bone flap along the marked perimeter. This step is referred to as the craniotomy (bone window).