Apple #259: Skull Removal

I know, this one sounds gory and maybe fantastic. And for some readers, it might be too gory. But it comes from a genuine concern and a medical question.

About a month ago I think it is now, a friend of a friend suffered a fairly severe stroke. She was taken to the hospital and despite their efforts to stop or slow the stroke, the pressure in her brain continued to build. To keep anything else from rupturing and causing irreparable damage, the surgeons operated and removed a portion of her skull to relieve the swelling.

She survived the stroke, has regained consciousness, and is able to talk. She still has problems with motor coordination in her right arm, sometimes she can't identify what day it is, and once she was convinced she was in Panama. She will have to go through a pretty long and probably arduous course of physical therapy before she will be able to return home. But the removal of part of her skull seems to have prevented even worse damage and, perhaps, her death.

In asking people about how she is doing, I also burn with curiosity to know about this opening in her skull, and the bit that was removed. These are not the sort of questions you can ask people who are wound tight with worry over her survival and her basic abilities to function. But still, I want to know, does she still have a hole in her skull? Some equally concerned and curious friends have suggested that maybe her skull will mend itself, the way a broken leg can knit itself. I'm skeptical about this, but I really don't know the answer. Other friends said the doctors kept the piece of skull they removed and at some point will put it back in, and that piece will knit to the rest of her skull. But where do you keep a piece of skull? And how long do they wait before putting it back in?


STROKES

• The term "stroke" means that something has happened in the brain to disrupt blood supply. That disruption in turn causes brain cells to suffer damage or die. There can be a lot of different kinds of strokes, occurring due to many different causes.
  

• Because strokes can vary quite a lot from one patient to another, some procedures are more appropriate than others given the type of stroke that has occurred.

• Most strokes are called ischemic strokes. In these, a blockage or a clot occurs in a brain blood vessel, and that obstructs blood flow.
  

Diagram of an ischemic stroke, showing the site of blockage up close and the damage to surrounding cells.
(Diagram from University of California, San Francisco Neurovascular Medical Group)

• In my friend's case, she had the far less common variety, a hemorrhagic stroke. In this type, a blood vessel actually bursts, and blood flows out into the surrounding tissue. This can cause damage to the nearby tissue which is not getting its necessary oxygen and nourishment.
  

Diagram of a hemorrhagic stroke, showing the site of rupture up close and bleeding at the surrounding tissue.
(Diagram from University of California, San Francisco Neurovascular Medical Group)

• In addition, the blood pouring out of the ruptured vessel begins to fill the brain cavity and puts pressure on the surrounding tissue.
  

• Left untreated, the buildup of blood can put so much pressure on the brain that it no longer fits comfortably within its protective coverings of the tough but flexible dura and the far less flexible skull surrounding that. Under such pressure, the brain can shift or re-settle within the dura, seeking more space. That re-positioning can force the all-critical brain stem to move and sometimes twist along with it. If such twisting occurs, blood flow to the brain can be cut off, resulting in extensive and severe neurological damage, and sometimes even death.

TREATMENT OPTIONS

• Methods of treating stroke vary depending on the type of stroke, as well as the extent of the damage at the time the patient arrives for care.

• Medications can be used to reduce the patient's blood pressure and so reduce the bleeding. Other very specific types of drugs can reduce swelling in the brain; and anti-seizure, anti-anxiety, and even more familiar pain relievers can be used to reduce any associated spasms, anxiety, or headaches.

• Many surgical methods of stopping the bleeding are also available. A surgeon can insert a clip (I picture this looking like those black office supply clips, but I'm sure they're far more sophisticated than that) over the site of the bleeding, essentially applying a tourniquet. They can also remove the piece of damaged blood vessel and replace it with healthier tissue. If a blood clot has formed, they can remove the clot itself and thus reduce the swelling that way.

Diagram of a surgical clip being placed at the neck of a ruptured blood vessel in the brain to stop the bleeding. (From the San Diego Neurosurgical Medical Clinic)
I knew it had to be more sophisticated than one of these:

• But in some cases -- apparently very severe cases, and when the patient's age and other factors would help him or her to recover sufficiently -- surgeons decide that the only way to reduce the swelling fast enough is to remove a piece of the skull. This is what the doctors decided to do in my friend's case.

DECOMPRESSIVE CRANIECTOMY

• The medical term for the procedure used in my friend's case is decompressive craniectomy: "cranium" referring to the skull, and "-ectomy" or "-otomy" indicating surgical removal.
  

• Surgeons practiced craniectomies as far back as the 1800s, but the technique became used less and less often when doctors believed that it resulted in too much damage, and that less invasive techniques might be preferable.

• It never fell entirely out of use, though, since emergency surgeons continue to use it as a last-ditch effort to assist victims of severe head injuries. Now some neurosurgeons who treat strokes are beginning to perform more craniectomies again.

• Specifically, here are the steps:

• Surgeon removes a part of the skull to relieve pressure.

• To provide some protection over the opening, the scalp is sewn to the dura, the inner membrane under the scalp. This allows some flexibility to accommodate any additional swelling, but also provides some protection to the exposed area.

• After the crisis of the stroke has passed, it can take about three months for the swelling in the brain to subside. The dura is left sewn to the scalp during those three months, and the patient may also wear a helmet for that time period.

• The piece of skull is kept in one of two environments to ensure that the bone marrow survives so that it can knit with the remainder of the skull later. One option is to keep the piece of skull frozen. Another option is to surgically place the skull in the patient's abdomen, in between the layers of muscle and fat. This keeps the piece of skull alive and healthy and acclimated to the patient's body.

• After the swelling has subsided, the piece of skull is either unfrozen or removed from the patient's abdomen, and re-inserted in its former place.

(Image from the Detroit Medical Center, sourced from Wayne State Medicine)


Bizarre, isn't it? But it's true.

Roy, of Siegfried & Roy, underwent this very surgery, following his near-fatal mauling by a white tiger. Surgeons removed about 1/4 of the right side of his skull to reduce pressure on his brain following lots of internal bleeding. They put the removed part of his skull into a pouch and inserted it into his abdomen. Nearly a year later, and after they had re-inserted the piece of bone into his skull, he had recovered enough to return home. He can now speak and write and walk with a cane.


Roy Horn in February 2005, a year and a half after the tiger attack and decompressive craniectomy.
(Photo from the Las Vegas Review-Journal)


By the way, this friend of mine is a long-time and deeply committed smoker. It is also a fact that smoking seriously increases your risk of getting strokes. Which means that quitting smoking will do a lot to help you avoid going through something like this yourself. The same could be said for not provoking any white tigers.


Sources
Pamela Linton, "Time and Space Heal Head Injuries," Wayne Medicine 1999
Ricker, Polsdorfer MD, Emory Healthcare, Surgical Procedures for Stroke, 2007
Treatment of Hemorrhagic Stroke at Mayo Clinic
Stroke from MayoClinic.com, reprinted at CNN's Health Library, July 5, 2006
"Hemicraniectomy for Subarachnoid Hemorrhage from a Giant Middle Cerebral Artery Aneurysm," Mount Sinai Clinical Program for Cerebrovascular Disorder, 2007
Tazbir et al., Decompressive Hemicraniectomy With Duraplasty: A Treatment for Large-Volume Ischemic Stroke," Medscape abstract, September 27, 2005
Ketter et al., "Outcome of patients after hemicraniectomy in malignant middle cerebral artery infarction after first rehabilitation," DGNC meeting abstract, April 23, 2004
Attia et al., "Decompressive Hemicraniectomy as a Lifesaving Procedure in Severe Acute Ischemic Stroke," Israel Medical Association Journal, September 2003
Stephen M. Silverman, "Report: Part of Roy's Skull Removed," People, October 16, 2003
Joelle Babula, "Roy awaits surgery to restore his skull," Las Vegas Review-Journal, October 16, 2003
IMDB, Roy Horn biography as of July 2004