Surgical Double Team
Inside Dual Spinal Surgery
April 9, 2019
This is a vivid account of a surgical procedure performed at City of Hope. The details may be disturbing for some readers.
Mike Chen, M.D., Ph.D. enters the cool, dimly lit operating room a few minutes after 2 p.m. Four nurses, two scrub technicians, a circulator, a monitor and an anesthesiologist move in a clinical dance around one another as they prepare for what will be several hours in the OR.
The anesthesiologist, Steven S. Tu, M.D., monitors fluids flowing into the patient while the scrub tech, Martina Rodriguez, assembles surgical instruments, her reflection glinting in the rows of metal objects.
Chen walks in having already spent hours performing a procedure on a different patient. The current case is a vertebrectomy, which involves removing a large, cancerous section of the patient’s spine.
“The patient is a 76-year-old who had a lot of pain around his chest and a history of prostate cancer,” says Chen, a neurosurgeon in the Division of Neurosurgery at City of Hope. “He has been progressively losing strength in his legs — he was barely able to stand before surgery.”
The patient is lying face down in a semicircular eggshell-colored vise, plastic draped over his lower body.
The surgeon and fellow by Chen’s side, Lisa Feldman, M.D., Ph.D. uses a sponge to rub a reddish liquid, iodine, onto the patient’s back, over the area where tumors have infiltrated the spine.
Across the OR, a nurse snaps off her gloves, tossing them into a nearby trash can.
Feldman begins draping the patient with blue cloth until, eventually, the only exposed part of his body is the eight-inch section of spine where she and Chen will do their work.
Feldman’s voice rings across the OR: “Can we get the lights on?” She and Chen don head lamps attached to magnifying glasses. The headpiece, which resembles scuba gear, is tethered to tubes. At the top, a light will later shine bright white into the opening where the surgeons operate.
Feldman is making an incision into the patient. In the background is the intermittent beep of the cauterizing gun that is cleaving the skin around the spine. Once the patient’s spine is exposed, the focus becomes identifying which parts of the thoracic region have been affected by cancer.
“Trying to figure out where you are in the spine is not as simple as you’d think,” says Chen, who then points to protruding bone. “This is T-1.”
He and Feldman identify the spinous process — a section of bone sticking out at the back of the spine. Once they locate that, and the area nearby that curves like a wing, they can determine where the T-2 vertebra is located.
“The apex of the curve is kind of in the middle,” Chen explains to Feldman.
“So about here?” asks Feldman, gesturing to an area while holding a drill.
“Can you go to 3?” says Chen to a fluoroscopy technician, who pulls up a visual of the T-3 spinal segment anatomy. Chen then turns to Feldman, saying, “Keep in mind where the screws will go.”
The whir of the drill fills the room as Feldman bores holes into the roof of the spine, called the lamina. Cancer is pressing on the patient’s spinal cord and removing the lamina takes pressure off it. The surgeons will then place temporary screws into the holes to help maintain alignment in the spine.
“You know the spine of a dinosaur, the part that looks like dorsal shark fins that protrude out?” says Chen, gesturing toward exposed bony parts of patient’s spinal cord. “That’s what these are. It’s called the spinous process.”
“Irrigation,” he says.
A nurse pours water into the opening in the patient’s back while Chen explains their approach: Go diagonally to reach the vertebrae affected by cancer. On their way, to create room to maneuver, remove part of the patient’s rib.
The dual spinal surgical approach is unique to City of Hope. The first time Chen performed a verbrectomy, it took 14 hours. A new approach — which Chen and fellow neurosurgeon Rahul Jandial, M.D., Ph.D., pioneered, and which is designed to reduce the number of incisions needed to perform this complex spine surgery — takes less than half that time.
The pair published a study about this approach in the journal Surgical Neurology International, reporting fewer complications, less bleeding and faster healing among patients in the study.
The OR team steps behind a protective barrier as a machine takes scans of the patient’s spine. Chen walks over and examines the scans and asks for a 15-degree shift for a better view. Feldman and Chen then begin counting vertebrae.
When they are satisfied they are in the right place, the long work of extracting diseased tissue and bone begins.
“Let’s switch to a regular Bovie please?” says Feldman, referring to an electric cauterizing device that cuts and clots blood at the same time. Slowly, systematically, she is exposing the spine, while at the same time removing bits of diseased bone.
Tiny rivulets of blood begin pooling inside the wound. Chen injects a sticky, white foam-like substance to staunch the flow, while Feldman uses a U-shaped needle to pull back the patient’s skin, allowing for a better view.
Chen counts again. “One, two, three, four, five — maybe go a little lower.”
He is instructing Feldman to mobilize a section of muscle off the spine to better visualize it. Feldman then performs her own count: “Two, three. You’re taking all this? Four.”
The counting continues — over and over — as the surgeons ensure they are in the right place in the spine.
Flecks of bone fly out of the wound as Feldman drills down into the spine. While Chen applies more white foam to the bone, Feldman works to avoid both the lung and a major ligament holding together the front of the spine — the anterior longitudinal ligament.
Soon, Chen will remove part of the patient’s rib to gain better access to the front of the spine. Chen then explains to both Feldman and, it seems, himself which structures he sees, and which to avoid.
“We go through the rib and, if you look here, there is a layer that lines the outside of the chest cavity called the pleura,” he explains. “Preserving the pleura ensures that you don’t damage the lung."
Chen then places a probe into the spine.
“Your drill is ready Dr. Chen,” says Rodriguez, the scrub technician supporting the surgery.
As Chen drills, a white powdery film of bone dust spreads through the cavity in the patient’s back. He pulls a large lump out as the process of digging a sort of “ditch” begins.
“The tumor has infiltrated the bone,” says Chen. “The bone and tumor are all together.”
The instruments Chen and Feldman use are small, so there is no undue pressure on the spinal cord. Feldman focuses on the top of the spinal cord, removing tiny bits of tissue as she works, while Chen does the same below it.
“Test for function,” calls out Feldman to the OR staff. “Can you run the motors?”
Feldman is requesting a type of electrophysiological monitoring — called motor evoked potentials — on the patient’s spinal cord. The system stimulates the motor, or movement, cortex of the brain, to provoke a response through the spinal cord and into the legs.
It is a way to ensure the patient’s legs are still functioning.
For the first time since the procedure began, the surgeons have a clear view of the tumor that has been pressing on the patient’s spinal cord. It appears, ironically, as an innocuous piece of tissue: a hump of white that has been putting pressure on the spine, causing stenosis — a painful narrowing of the already crowded spinal area.
“You see that thick band of tissue,” says Chen, gesturing toward the tumor. “The part that looks like fat? That is cancer that’s been wrapping around the spinal cord.
“There isn’t much space in here so the tumor is really putting pressure on the spinal cord itself.”
Chen adds that the spinal cord will be completely decompressed once the tumor is removed.
“Right rib lesion for permanent,” says Chen. In a call and response that is typical for OR staff, a nurse repeats Chen’s words and takes the tissue sample.
The nurse then calls out to a colleague, “Epidural lesion for frozen,” indicating that a frozen section, or a rapid pathological analysis of the tissue, is to be performed.
Meanwhile, Chen and Feldman are discussing the tumor.
“See the tumor going out here,” says Chen to Feldman as he points at the yawning hole in the patient’s back.
“Nasty tumor,” says Feldman.
“And there’s a nerve,” says Chen.
“It’s all distorted,” says Feldman.
“It’s being pushed down,” says Chen.
Chen explains that as part of this procedure, he and Feldman will need to sacrifice nerve roots to reach the spine, but that this process will relieve the patient’s pain.
Chen cuts into a junction between the rib and spine, while Feldman isolates and dismantles the top of one of the diseased vertebrae.
“When you disconnect the pedicle then the superior facet becomes loose,” says Chen to Feldman.
“I couldn’t find the pedicle before because it was beaten up by the cancer,” says Feldman.
Feldman continues digging with the drill, checking in periodically with Chen to determine how deeply she should push and working to avoid damaging nerve roots. The bone she is working around is spongy because of the cancer, the consistency of a marshmallow. Normal bone is solid.
“The nerve root is right there, around the corner,” says Chen to Feldman as he points. “So I would just unroot it.”
The nerve root the surgeons have been working to identify is exposed. They begin to excise it.
“Here’s an epidural specimen,” says Chen as he pulls sections of bone from the patient’s spine. A nurse answers by repeating Chen’s call — “epidural specimen” — before preparing the tissue for pathology.
Chen turns to Feldman, guiding the path she is forging with the drill: “If you drill here you’re going to connect with me.”
Feldman pulls out a large chunk of diseased bone and celebrates, but moments later encounters a bit of calcified bone.
“This is so hard,” she says. “It’s sclerotic.”
By now, the surgeons have created a cavernous space in the spine. While Chen continues the painstaking process of digging, Feldman cuts a wad of fat from the patient to form a graft.
Soon, Chen is weaving a web of sutures he will use to create a larger opening in the surgical site. He stuffs the open space with fat; Feldman follows by tying up sutures to secure the grafts.
“When the tumor really adheres to the dura, it creates holes,” says Chen. “The fat is like a stopper in a sink.”
At this point in the procedure, the spinal cord appears as a white tube, floating above a dark cavernous space below it.
All that remains for Chen and Feldman is to pluck remaining bits of diseased tissue, and later implant a titanium metal cage that will support the parts of the spine removed during surgery.
As part of this process, Chen begins twisting screws into healthy spinal bones. Feldman does the same, but meets resistance.
“I can’t tell if this is the sclerotic bone we were talking about earlier,” says Feldman to Chen.
When the screw is finally set, Feldman lets out a cry of relief and happiness.
“Guys can you go to the PowerPoint slide labeled T-2?” says Chen. He and Feldman prepared a slide deck of key images prior to surgery to determine what size screws he needs to implant to hold the spinal cage.
“This is the cage,” he says, holding up a metal contraption about the size and shape of a chalkboard eraser. “It’s a giant.”
The cage will replace a section of spinal cord, and will need to be carefully positioned so as not to damage delicate structures and surrounding bone.
“If you look at the CT and spinous process, it’s angled a little more medially than I like it to be,” says Chen to Feldman, explaining challenges to positioning the cage.
Chen requests an intraoperative ultrasound as a more serious tone sets in in the OR. Implanting the cage correctly determines whether the patient will be able to walk and function properly postsurgery — the culmination of all the surgical work done thus far.
“Go to the T-5 slide,” says Chen as he and Feldman look at a scan of the spine to ensure they are navigating the structures correctly.
After a few rounds of scanning and assessing, Chen requests the best sized cage to implant. He and Feldman use special devices to attach it to nearby vertebrae that will help support it.
“Alright, you ready for X-ray?” asks Chen. “Irrigation.”
Chen directs staff to perform X-rays to ensure the cage and screws are in the correct places, and measuring angles to determine the best position for the cage.
“Too much of an angle and we will have one part of the cage flush and one not, which will create pressure on the spine,” explains Chen to Feldman.
The cage is implanted.
“We’re the only ones who do this surgery this way,” explains Chen, while calling for final motor tests on the patient to ensure no damage occurred during surgery.
“There are other ways to remove an entire vertebral segment,” says Chen. “Easier ways. Why do we do it this way? We avoid going through the patient’s chest cavity, which increases the invasiveness of surgery and requires an additional incision.
"Ultimately, most people don’t do it this way because it’s difficult and requires a lot of experience. Now with modern instrumentation and better anesthesia, we are able to do this safely.”
The surgeons are irrigating the wound and sprinkling antibiotic powder into it.
“Beautiful,” says a nurse, marveling at the cage moments before the wound is closed.
The anesthesiologist, Tu, verifies that the patient is breathing on his own.
By the day after surgery, the patient is walking. A week later, he is home.
“His balance is better, his pain is improved,” said Chen a few weeks after surgery. “The surgery was a success.”