Gray Matter

by Kilpatrick, Joel;Levy,David

  Even in a healthy person with wide-open arteries and veins, getting to the diseased area in the brain is often more difficult than, say, in the heart or other parts of the body. This is because of the tight corners to get around as the arteries enter the skull. The carotid or vertebral arteries, which begin in the chest, travel through the neck and become the brain vessels, taking multiple hairpin turns as they enter the skull. This tortuosity of the vessels, as well as the fact that the curves cannot be straightened because of the bone structure, means that the devices you would use in heart surgery will not work in brain surgery. The stents, wires, and catheters have to be much softer and more flexible. It is delicate and tricky territory no matter how healthy the patient. With Daniel it was much more difficult.

  I found I couldn’t even enter Daniel’s vertebral artery with the guide catheter because the vessel was so hardened with plaque. The artery was much narrower than normal and had hard little bumps all around the inside, like the surface of a gravel road. This put us at a major disadvantage because without a catheter in the artery we could not see clearly what we were doing. Usually, I inject dye through the guide catheter directly into the artery so my team can snap a movielike series of X-ray pictures to see where the instruments are positioned in relation to the aneurysm, and so on. Because the guide catheter could not be brought into the entrance of the vertebral artery, which was only inches away from the heart, the dye was diluted and didn’t give us good quality pictures. Not only that but, as is common, the vessels I was working on had moved because of the introduction of my instruments. The aneurysm was not even in the same place it had been, so getting a new visual was even more important. Frustratingly, I just couldn’t get the dye up to where I needed it.

  The human body has two vertebral arteries that supply the brain stem and upper spine with blood. I was now blocking one with the catheter; the other was picking up the slack, but it was very small and could do that for only a limited time. I did not know how long; I just knew that the sooner we pulled out of his vertebral artery, the sooner his brain stem would have its full supply of oxygenated blood. Daniel’s case was taking much longer than we had hoped. I wanted to move quickly, but the disease in the vessels was causing delays at every turn.

  I felt around the insides of the vessels with the wires, sliding them along blindly using feel, experience, and my imagination to “see” the shape of the vessel since the road-map scan we had made was no longer accurate. My goal was to re-create the aneurysm neck with stents so I could then block off the weakened part of the wall with platinum micro-coils. These tiny coils feel very soft; they are used to fill space and act as a resistor so blood no longer flows there. They have a helical shape and want to form a ball. The body eventually solidifies around the ball. This is the common medical way of patching a weak point in a vessel wall.

  Normally you check the position of the aneurysm in relation to the stent before deploying the stent. In this case we couldn’t, because we couldn’t get a decent picture. If I did not properly place the stent, I ran the risk that the coils would slip out of the aneurysm and block the vessel itself, causing a major stroke.

  I placed the stent across the neck of the aneurysm, inserted the amount of coil I believed was needed to fix the aneurysm, and then waited. Daniel’s vitals remained normal. We took a final-run angiogram to see if the aneurysm was repaired and all the vessels in his head were filling with blood. We noticed that the vertebral artery in the neck looked a little bit rough, as if the walls had been slightly damaged during the procedure; usually this type of damage would heal on blood thinners, which Daniel had been taking. His vessels were in such bad shape to begin with and had endured so much during the surgery that the damage seemed par for the course. The angiogram showed us that all the sizable vessels in the brain had good blood flow. There was nothing more for us to do. I removed the wires and catheters and sealed the puncture site in the femoral artery with a clip device.

  My team and I breathed a collective sigh when the lengthy procedure was over, but we never feel real relief until a patient wakes up and is able to talk and move his or her fingers and toes. Only then do we know how the procedure has gone. There is still much we do not understand about the brain—the fact that the angiography and scans look good doesn’t guarantee that the patient will wake up neurologically normal. Until that happens, we feel suspended in time.

  I went to get a drink of water, then began reviewing the angiography images and writing in the chart while waiting for Daniel to wake up from the anesthesia. Most patients wake up in fifteen minutes or so. If they are obese, which Daniel was not, it might take longer to wake up because the drugs get stored in the fat and are processed out over a longer time. At a certain point, Daniel’s anesthesiologist said that by now the drugs should be out of his system—and still he was not waking up. Had something happened during his surgery that I was not aware of? To my relief, the CT scan showed no hemorrhage.

  After an hour and a half, he fluttered his eyes. A little while later, when most patients are able to carry on a conversation, Daniel could hardly speak. When he tried, his words were slurred, and he couldn’t move one side of his body. It looked as if he’d had an embolic stroke. An MRI scan confirmed a small stroke, but not just any stroke—it was in the brain stem.

  There are two kinds of strokes. An embolic (or ischemic) stroke is caused by a piece of plaque from the arterial wall or a blood clot that lodges in an artery and stops the blood flow, depriving brain cells of critically needed oxygen. Bleeding (hemorrhagic) strokes occur when an aneurysm or vessel ruptures and blood goes into the brain. We were trying to prevent a bleeding stroke by fixing Daniel’s aneurysm. In the process, he had an embolic stroke instead.

  Relative to other parts of the brain, the brain stem has important functions packed in a very small area. Nerve fibers taking the commands and information from the surface of the brain come together like a funnel as they travel through the brain stem on their way to the spinal cord. The brain stem is the center of consciousness, involuntary and essential functions such as breathing, and much more. People can stay alive without their frontal lobes, but not without their brain stems. A small stroke that might not be noticed in the forebrain can cause hemiparesis (weakness on one side of the body) or worse if it occurs in the brain stem.

  I was fairly certain that a piece of cholesterol plaque must have come loose from Daniel’s vertebral artery and lodged in a small artery feeding the brain stem. Too small for us to see on an angiogram but large enough to cause damage, the piece of cholesterol blocked blood from reaching that small part of the brain stem. Over the next few hours it became apparent that Daniel was not the same person he had been when he went in for surgery, and his prognosis became uncertain: He might get worse. He might get better. He might remain paralyzed. He might not regain function or speech. He had been pretreated with blood thinners before the surgery, and his blood thinners, which now were the only treatment available for his stroke, were continued after the surgery. There was nothing more I could do for him medically or surgically.

  Once we had a handle on what had likely happened, I went to talk to Nellie and escorted her out of the waiting room and into a passageway.

  “The surgery to repair the aneurysm appears to have been successful, but Daniel had a stroke during surgery,” I said. “The procedure was very difficult because of his diseased vessels. I wish I could tell you what the final outcome will be, but I can’t. It’s very much up in the air right now. Many stroke victims recover significantly, and we are doing everything we can to treat Daniel’s new situation.”

  Nellie took this in, then looked at me questioningly.

  “Did you know he was going to have a stroke?” she asked.

  “Pardon me?” I said, thinking I had misheard her.

  “Did you know he was going to have a stroke? Is that why you prayed?” she asked again.

  The question confounded me for a moment.

  “No,” I said, “I d
idn’t know he was going to have a stroke. It’s my habit to ask to pray with everyone before surgery.”

  “Because that really scared him—when you prayed,” she said. “He didn’t think it was serious before that.”

  I was surprised, but this explained his turning somber and quiet afterward.

  “This was a very high-risk surgery, and I thought I had made that clear,” I said. “But no, I didn’t know he would have a stroke. I ask to pray with everyone.”

  Nellie seemed unsettled by the stroke but satisfied that I hadn’t known beforehand that it would happen. I accompanied her back to the waiting room. Daniel was slow to recover, but over time he regained much of the function he had lost. They both came and saw me for a follow-up six months later. I had no idea how the experience had affected them long term, if it had at all. My hope, naturally, was not only that he continue to regain his physical function but that they were prompted into a fresh consideration of their spiritual beliefs. That remains between them and God.

  * * *

  Often the reluctant person is a family member, and in one case it was the highly educated grandfather of a very bright eight-year-old girl named Tina. Tina was in the gifted program at school, played the saxophone, and excelled in language arts and history. One day while playing her instrument, Tina discovered she could not breathe through her right nostril. Decongestants didn’t work, so the family took her in to have her checked out. A scan showed a large vascular tumor sitting against the carotid artery and filling the entire right side of her face. It was even causing her cheek to bulge in one area.

  Tina came to see me with her parents, Tammy and Richard, and her grandfather, Dr. Willard, who I soon learned was a retired medical doctor affiliated with Harvard University. He wanted the girl to go to Boston for treatment at one of the academic hospitals he was familiar with. I told him that I felt comfortable doing the procedure but that he was welcome to get a second opinion wherever he liked. Because of the risks involved, it was important that they have confidence in whoever was going to do the surgery.

  At our consultation, I recommended embolization, which means blocking the blood supply to the tumor with a “glue” injected through the artery. Embolization would be dangerous in this case, because the tumor was getting blood from the ophthalmic artery and other arteries off the carotid. If the glue went into these arteries, it could cause blindness or stroke. The procedure would also take many hours and therefore require a significant amount of radiation. A second surgery, done by our excellent skull base surgery team, would require an incision under Tina’s eye and down the side of her nose to open up the facial area and remove the tumor, which was invading the temporal lobe of the brain.

  Although Tammy and Richard had confidence in me and wanted to have the surgery in San Diego, Dr. Willard wanted his granddaughter treated across the country, in Boston. Under somewhat awkward conditions, Tina’s parents decided to move forward with my embolization procedure, followed a few days later by open surgery to remove the tumor. When they returned for the pre-operative visit, Dr. Willard was sitting with the rest of the family. I could tell that he had not warmed up to the idea of my treating Tina, and I felt he was watching me for any slipup that would signal a lack of professionalism. Once again I explained the risks to them. Then I turned to Tina and drew a picture on the whiteboard of a mountain and a trail winding back and forth to reach the top.

  “Have you ever been on a hike up a mountain?” I asked her.

  “No,” she said, “but I have been on some hikes that were really long.”

  “Good,” I said, “so you get the idea. The path that we are setting out on is a long one. It will involve two separate procedures and two separate doses of anesthesia. It will require you to recover from one procedure and then have another one in a week or so. There are risks involved in both procedures. I am confident that we can get you to the top of this mountain, but it may seem like a long journey for someone your age. Do you understand?”

  “Yes,” she said.

  At the initial consultation, I had asked Tammy if she and her husband were raising Tina with a faith or religion. “No,” she had replied, and Tina quickly added, “But we have a Christmas tree.” I never want to make people feel awkward, but you have to do the best for the patient. I knew I had the training and skills to do the procedure successfully; I had previously treated tumors like the one behind her face. However, I wanted to offer Tina more; I wanted to offer her prayer. This time, my heart was pounding. It would have been easier to proceed had there not been a Harvard doctor in the room who already probably thought my colleagues and I were inferior to the surgeons he knew in the Northeast.

  “It is my habit to pray with patients,” I said boldly. “Would it be okay if I prayed for Tina?”

  Richard looked at Tammy. Both looked surprised. She nodded yes and looked down at the floor. Dr. Willard stood up.

  “I will wait in the waiting room,” he said as he grasped the door handle and walked out. Clearly, he wanted no part in the prayer. I swallowed hard but moved ahead with what I felt was the best for the girl. It took some courage, given Dr. Willard’s response. I moved over to Tina and put my hand on her shoulder.

  “God, thank you for Tina,” I prayed. “You invite us to ask you for what we want, and I am asking for your help and for success for both of the surgeries without any damage to Tina. Please give peace to her and her parents. In Jesus’ name, Amen.”

  Tina seemed intrigued by the new experience and not apprehensive in the least. Tammy wiped tears from her eyes. With a feeling of sobriety and expectation I stood and walked them to the waiting room where Dr. Willard was. I would see them the following day.

  Early the next morning I went into the pre-op area to see Tina and her mother. Tammy exclaimed, “I had a dream last night that the tumor was gone.” I smiled at the hope in her voice. When I examined Tina’s face, I shook my head. It was still swollen where the tumor was: she would need the two long surgeries. I held her hand and Tammy’s, said a quick prayer, and the transportation team wheeled Tina into surgery.

  I put on my blue two-piece lead suit and a neck collar to protect me from radiation “scatter” while working with the X-rays. Donning a surgical hat and mask, I entered the procedure room where Tina lay unconscious, draped in a blue cloth with only a small patch of skin exposed over the femoral artery. She was lying on a table attached to a multimillion dollar, computerized machine that was necessary to see with detail through the skull and into the brain vessels. Two technologists were there, one dressed in a sterile gown and gloves to assist me, and one running the machine and opening supplies for us from the back table as needed. The anesthesiologist sat on the other side of the table behind leaded glass.

  I felt for a pulse in Tina’s femoral artery as it crossed her hip. As usual, I paused for a moment to remind myself that this was a person and not a project, which is easy to forget in a sterile environment. “God, keep her safe,” I said before placing a long, hollow needle in her leg. We enter this artery because it travels over the femoral head, a large bone that allows compression of the puncture site after the procedure. The carotid artery in the neck is closer to the brain, but compression of the neck to seal the entry site after the procedure is more difficult and dangerous.

  The red blood dripped rapidly back from the needle, indicating that I was in the artery. I inserted a wire through the hollow needle, then pulled out the needle and slid over the wire a tapered plastic tube or sheath, like a drinking straw with a narrow pointed tip and a one-way valve on the end. One of the techs handed me the sterile catheter and guidewire. I slid it through the one-way valve in Tina’s leg and began the journey through the vessels to the tumor in her head.

  Endovascular neurosurgery is surprisingly tactile. With your fingers you insert a guidewire, less than one millimeter in diameter, and a two-millimeter guide catheter into the femoral artery. By hand, you gently push these up toward the heart, with the guide catheter sliding up over
the wire in coaxial fashion. Feeding the wire involves fine finger movements, not unlike those used in sewing or spindle work. None of it is done by machine. The guidewire has a curve on the tip and can be directed into different vessels by rotating it. If you feel resistance, you have to stop and figure out why. All movement must be calculated; extra or exaggerated movement is dangerous. Experience tells you what kind of resistance you are meeting as you watch the wire move through the body.

  I gently pushed the guidewire and the guide catheter against the flow of blood coming down from Tina’s heart. Within moments I reached the top of her aortic arch, where three main vessels branch off to the neck, face, and head. I had gone against the flow of blood coming up from the leg, and now I would go with the flow to the head.

  Across Tina’s body from me during the procedure were several large screens. When I stepped on the floor pedal, the machine would come to life and show a live image of the field of interest. I watched on the screen as X-rays flowed where I directed them and Tina’s gray, beating heart became visible between her white, air-filled lungs. The metal wire was black against the gray background. We always check carefully for air bubbles in the lines and in the contrast dye we inject. Anything injected from this point will flow into the brain, which pulls in blood like a vacuum. I knew in advance which of the three branches led to the tumor. From three feet away, I rotated the guidewire and watched on the screen as it flipped up and into the carotid artery. There was a sense of accomplishment at every step. All this was done by feel and by knowing where the different arteries branched off the aortic arch.

  The procedure was going well, and I was thankful that Tina was young. The older that people are, the more tortuous their vessels can be and the more difficult it is to get to where you want to go. You can struggle for more than an hour just getting the guide catheter in place, as I had done with Daniel. Arteriosclerosis, calcification, and a general slanting of the vessels with age make them curvy and difficult to navigate. These factors also make it dangerous to straighten out the vessels with your instruments because this can break plaque off the sides, which can travel to the brain and cause a stroke. Young, malleable vessels are much easier to work in, and Tina’s vessels remained beautifully flexible.