ST. LOUIS, Mo. (Ivanhoe Newswire) - Neurosurgeons have long considered tumors in deep areas of the brain inoperable, giving patients very few treatment options, and often, little hope. A new tool is allowing doctors better access to those hard to reach sections of the brain, using a minimally-invasive approach to remove lesions.
Fifty-three-year-old Bob Benner loves taking an active role in his son’s sports.
Right now Bob is sidelined, recovering from a life-threatening condition.
“Pounding headaches, the sun hurt. Hit a bump in the car, it hurt. Headaches all the time,” Bob Benner told Ivanhoe.
Doctors diagnosed Bob with cancer in his back, and another tumor deep in his brain. The idea of brain surgery was frightening.
“Are you going to be able to talk afterwards? Walk?” said Benner. “Are you going to lose your sight?”
A new tool is now giving surgeons options where none had existed before. The brain path allows doctors to reach deep areas in the brain, without disturbing critical nerves and tissues.
Using computerized mapping of the brain, surgeons make a small opening, and insert the tube.
“The brain is not a smooth surface, so we then go through one of the valleys of the brain,” said Jeroen Coppens, M.D., Department of Neurosurgery specializing in vascular neurosurgery and neurooncology at St. Louis University Hospital.
Doctors can see the tumor using cameras in a port. The brain path also allows doctors to remove the lesion.
“The tumors can be anything from the size of a pea to the size of a golf ball,” Dr. Coppens explained.
When doctors remove the tumor and the brain path, the brain tissues move back into place leaving just a small scar.
Bob Benner’s cancer is in remission. Now he’s looking forward to cheering his son on, next season.
Doctors said the brain path can also be used effectively for patients with hemorrhagic or bleeding stroke, which can result in brain damage, paralysis, or death.
RESEARCH SUMMARY
TRADITIONAL BRAIN SURGERY: With most traditional brain surgeries, surgeons have to open the skull and find the best trajectory; there is no pathway leading directly to the tumor. The type of brain surgery performed depends on the condition being treated; there are generally four categories of surgery: a craniotomy, a biopsy, endonasal endoscopic surgery (minimally invasive) and neuroendoscopy (minimally invasive). A craniotomy involves creating a hole in the skull with enough space to maneuver in the brain tissue to remove tumors, clip off aneurysms, or drain blood/fluids. A neuroendoscopy is a combination of a craniotomy and an endonasal endoscopy. The method uses a small endoscope to remove tumors; however a small hole in the skull is still necessary. Unlike the previous procedures, an endonasal endoscopy does not involve making a hole in the skull. Instead, the surgeon accesses parts of the brain through the nose and sinuses. This method is used for tumors on the pituitary gland, at the base of the skull or those that spread across the brain. (Sources: Interview with Dr. Coppens, on.nc5.co/1LM1RQY, on.nc5.co/1CZ6NOn)
THE BRAIN PATH: A new device, called the Brain Path, which is a combination of advanced technology and computerized systems, now allows surgeons to avoid some high-functioning areas of the brain when performing surgery. Surgeons can perform through smaller openings using pre-mapped angles and trajectories in the brain. The actual device is integrated with a computer system and has a cannula, or tube, through which the surgeon operates. Jeroen Coppens, M.D., a neurosurgeon at St. Louis University Hospital, told Ivanhoe, “You’d be surprised that even though the tube looks small, you’re able to remove lesions that have a diameter that are multiple fold the size of the tube.” Another aspect of using the Brain Path is that the procedure can be performed on a patient while asleep in the O.R., or when they are awake during MRI imaging. For the patient, all that is left is a scar approximately the size of a quarter. (Source: Interview with Dr. Coppens)
INTERVIEW
Jeroen Coppens, M.D., Department of Neurosurgery specializing in vascular neurosurgery and neurooncology at St. Louis University Hospital, talks about a new device that allows surgeons to target areas of the brain more precisely allowing for more opportunities to operate on previously inoperable conditions. (Interview conducted by Ivanhoe Broadcast News in September 2014.)
I want to talk a little bit about brain surgery. What’s the gold standard if someone has a brain tumor or something that you need to operate on, how do you proceed?
Dr. Coppens: There’s been a big evolution over how brain tumor surgeries are done. The traditional way is to open the skull fairly extensively and then try to find the best trajectory to get to the tumor. For superficial tumors, they are easily approachable. The main challenges are tumors that are deep seated in the brain. They require you to go through a lot of normal structures to try to get to the tumor. We developed computer systems and developed better ways of trying to find what these normal structures are and what their function may be. Instead of just taking the shorter distance now we’re putting more emphasis on trying to find the safest distance or the one that leads to the least amount of destruction of structures that would have a lot of functional impact. More recently we developed ways to do this by limiting the openings using computer systems, having advancements in imaging in trying to predict where functional areas are in the brain. More and more the goal is to try to do the surgeries through smaller openings with direct trajectories that are preplanned. The path taken down to the lesions we want to remove are studied beforehand in a very precise fashion to really try to get there with minimal violation of normal structures and minimize the potential of side effects or the potential detriment that can come in the balance of removing the tumor versus the normal structures we go through.
What’s the benefit to the patient to be able to use that smaller opening and the more direct trajectory?
Dr. Coppens: The benefit is there’s less healing. The incisions are smaller so there is less tissue dissection that’s done. And then the main benefit is that the pathway we utilize can be studied and we can have a lot of detail in approaching a lesion to minimize structures such as areas of the brain that control speech, vision, sensation, and coordination. The goal is to try to really be able to go down deep in the brain and remove the lesion so that the patient may wake up from the surgery and be the same way he was before surgery , as well as, have the benefit of having the tumor removed to prevent it from growing and potentially lead to more problems.
What kind of size or area are you talking about? When you’re talking about the brain you have to be very, very precise don’t you?
Dr. Coppens: Yes. We are talking about accuracies that are within a millimeter or two. The lesions we remove can be the size of a pea to something to the size of a golf ball. The location and the length of time the tumor has grown also factor into our planning. In general these minimalistic approaches are very well suited for something between the size of a pea and a golf ball situated fairly deep down in the brain.
When you’re talking about something the size of a millimeter, what is the risk to the patient if you are not precise? What concerns are there?
Dr. Coppens: The risk is directly related to the trajectory and the location of where the tumor is located. The brain is an organ where there are still a lot of things we do not understand but we do have a good idea of certain functions in certain areas of the brain and more and more of this can be studied before surgery by having people do tests and MRIs. Certain areas of the brain will light up which will give us a good idea of where to expect certain functions and the risk of how to approach one specific tumor is inherently specific to every case. Knowing where the structures are based on the location of these tumors, the risk to the patient can be anything from paralysis and loss of sensation, loss of speech, a visual problem, and a combination of problems. The risks are very inherent to carefully studying these before surgery. We conduct benefit to risk ratios to help decide who will benefit from this surgery by looking at the risks and benefits and analyzing if the risks (including those risks regarding the trajectory and approach) outweigh the benefits. With time the risks are decreasing with the different technologies being made available and we are getting better at accessing the lesions. Better removals leas ultimately better outcomes.
Talk to me about the brain path.
Dr. Coppens: The brain path is a tube developed to be integrated within what we call the six pillar approach. There is improvement in the studying of the anatomy before surgery, there are improvements in using the computer systems to study how to get to these deep-seated lesions. There are improvements with the device itself about how we can open up the different parts of the brain. The brain is not a smooth surface, it has a lot of hills and valleys. The device enables us to go into the natural pathways, into these valleys, and minimize how much brain we go through to then be able to cannulate into the brain and then through computer systems target a very specific area on the brain. Then there has also been developments in the optics; traditionally all the surgeries are done through a microscope, now there’s been development of a camera which has some advantages which enables us to do the surgery through that port. The surgeon then looks at a screen and ultimately we can do these resections through very small openings and very targeted areas. This is actually a device that gets integrated with computer systems. The idea is this is a tube itself through which ultimately we operate and this is a cannula and it enables us to get into the brain. As you will notice this has a little bit of a pointy edge and that’s the idea so that it can, instead of cutting through the fibers, dilate them while we bring this down. There is a wand that gets inserted into this and then through a computer system, we can pick exactly where we want to go in the brain and then under direct constant feedback from the computer system we can choose a trajectory and slowly advance and keep track of how deep we are going. The idea is then to ultimately remove the inner cannula which then attaches to retractor system and then we are looking through this port and we are purely targeted exactly either on the surface of the lesion one approach or into it based on what kind of either tumor, if it’s a hemorrhage. There are some different strategies then about where to place the port exactly in relationship to the surgical target. The benefit is that the tube does not get removed through the surgery and the whole surgery is done with the tube in place. Just by doing a little manipulation we can change the angles and at the end the tube is removed. The brain then collapses on itself and the fibers that were distended come back to their normal anatomic position which leads to less destruction of them and much more minimal trajectory within the brain tissue itself. This is the device itself it has an inner cannula which is removable. This is the tube itself which is hollow and enables us to operate through. The device is initially inserted with a wand which is actually inserted within the blue portion. That enables us to keep track of where the tip is at all times through a computer system. The brain is not a smooth surface so we then go through one of the valleys in the brain, as we then touch that with the wand we have the computer system which tells us exactly what the angles are, what our trajectory is, what structures we’ re going to go through. This then gets sent in the advance in the brain under direct visualization through the computer system as we advance this the goal is to then have the tip get to the target. As that happens, we gently advance this by a centimeter which compensates for the distance. The inner cannula then gets removed, the tube ultimately then gets attached to a rigid system which is not fixed to the patient but more to the table just so there’s no movement while we operate. The camera enables us to directly visualize through that tube and then we can use instruments and work within the diameter of this tube. Using both of our hands we can do very precise things in going in and cutting and dissecting around the tumor and removing portions of the tumor. You would be surprised that even though the tube kind of looks small and you’re able to remove lesions that have a diameter that are multiple fold the size of the tube. As you remove things then you can gently maneuver the tube around a little bit and change the angles. Also as you remove the tissues the brain has a tendency to then make the walls of the lesions come back together and so you’re actually able to remove very sizable lesions just through this very small trajectory. That’s where the benefit ultimately is. Towards the end of the surgery then the tube gets directly removed out of the brain and then the brain tissue reforms itself and re-obtains its normal structure with the fibers regaining their normal trajectories. This just forms a tiny little scar which is in the trajectory in which we go through to get to the ultimate target.
You had mentioned that the brain just kind of forms around after the tube comes out. So there’s no need to go in and suture or anything like that?
Dr. Coppens: The brain tissue itself is not a rigid structure; it has a little bit of malleability and elasticity in it. The suturing is done more on the superficial layers and then the bone gets replaced with little plates and then that’s more the standard closure. The benefit is the opening can be done though an opening about the size of a quarter instead of opening the bone over an area of two to three inches to have full exposure. In the end the incision itself is probably about an inch to an inch and a half. You can really go down deep in the brain do a very sizable resection of a fairly large tumor and ultimately the you know the scar and then the trajectory is so precise that it enables us do it through a very minimal opening.
Tumors that were at one time considered inoperable are they now accessible with the tool?
Dr. Coppens: Some are. Everything that’s been considered inoperable is because either it was too deep or there were too normal structures around it or at the time we didn’t understand the anatomy. The combination of all of these developments in technology, preoperative imaging, and understanding functions, make some tumors that were deemed to be inoperable now operable. By minimizing the risk it’s just a balance of what’s considered inoperable and what potentially is approachable.
In terms of additional benefits to the patients is there less hospitalization, quicker recovery?
Dr. Coppens: Yes. Most patients do very well if you have a complete resection and you have a very clean field and you didn’t go through any structures that have clear functional importance. Some patients will go home the next day after the surgery and there’s a lot less pain. People are on less pain medication afterwards. This does decrease the hospital stay; it does decrease the amount of bleeding involved and for a lot of patients that will translate into a shorter hospital stay as well.
Do you ever speak about Bob Bennett’s case? Are you able to talk about the benefit that this has for him? What benefit does that have?
Dr. Coppens: Bob had a tumor that was just lateral to what we call the atrium. Without getting technical, it is a portion of the brain just at the intersection of the fluid spaces of the brain. The difficulty in accessing those regions trajectionally is that we know that the visual pathways that control your vision actually become superficial to that and kind of drape over this area. The difficulty in removing a tumor in this area is really mostly the risk to going in and going through some fibers that are considered normal visual fibers and for someone to then wake up and potentially have lost part of the vision. Of course there are other risks of bleeding and then other things but the main concern traditionally for this location of that kind of tumor was the visual outcome. What we were able to do in Bob’s case is we studied some other preoperative imaging and we noticed that in his specific case the tumor had pushed these fibers up somewhat. It was still draped over it but the fibers were pushed a little bit on towards the somewhat up compared to their normal position. By studying the MRIs we felt that Bob was a very good candidate for using this technology. Coming down somewhat lower and picking a trajectory to avoid these visual pathways we were able to go from the bottom of it coming out at an angle that was a little bit more looking up. By coming up, we were able to then have our tube set at a 30° angle up. Doing the whole operation through the tube while the visual fibers were probably just in contact here and being pushed up a little bit gave us this small corridor to be able go and remove his tumor and then come back out and the visual pathways then were able to come back down. The whole benefit in his specific case was to be able to do the surgery well not only in a minimally invasive fashion but more importantly also to make sure we could avoid the visual pathways and make sure that the risk benefit ratio here was not just in saying I can take your tumor out but you’re going to lose vision. We were very pleased that Bob was able to do very well from the surgery. He was discharged the next day his vision remained intact and he’s had a very successful outcome from the surgery.
Is there anything I didn’t ask you about this technology that you think people need to know?
Dr. Coppens: There’s also the whole aspect about if we feel that functionally it cannot be located. There are questions about whether or not the tumor can be seen or whether not the risk is so great about putting someone to sleep you know this can be combined with someone awake while you test them while they’re awake and you do the surgery.
You can do this awake and asleep?
Dr. Coppens: Yes. You can do this in the intraoperative MRI. And then you can do MRIs while the tube is still in, allowing you to verify that you have resected it all. This is really complementary with the whole range of anything from awake operations to using intraoperative MRIs or other forms of intraoperative imaging, or intraoperative ultrasound. The other thing is, it’s not all about tumor then there’s a whole aspect to this about intracranial hemorrhage. People who have had bleeds down in their brain in the past, these were kind of considered where mortality is very high and a lot of people won’t even operate on them. A lot of big trials we’ve had have never shown surgical benefit because the problem is that the deep ones the surgery is so destructive. Now this is just the beginning of the experience, but we are starting to push the envelope a little bit also on intracranial hemorrhage on actually using this device to be able to the same way find the trajectory that’s very minimal in terms of destruction of normal fibers to minimize the risk. A lot of times we’ll just go over the eye and then go in deep. Traditionally we used to come from above but this enables us to go in areas that are a lot more silent in the brain and then this is a great tool too for intracranial hemorrhage. Then the hemorrhage kind of delivers itself. You go in, you clean it out and you come out. Here we’ve talked about tumor but hemorrhage potentially is a big application too.
FOR MORE INFORMATION, PLEASE CONTACT:
Allison Tabeta
(314) 577-8152
atabeta@slu.edu
