Intraoperative Monitoring - Carter Beck, MD

Dr. Carter Beck: Interview

Dr. Sechrest: Hello, I'm Dr. Randale Sechrest, your host for eOrthopod.TV. Today I have as my guest, Dr. Carter Beck. Dr. Beck is a neurosurgeon. He did his medical school training at the University of Chicago School of Medicine. From there he completed a neurosurgical residency at Stanford University. Good morning, Dr. Beck.

Dr. Carter Beck: Good morning, Dr. Sechrest.

Dr. Carter Beck: Dr. Beck, what I would like to discuss over the next half hour is a new procedure, a relatively new procedure in most spine surgery practices, which is referred to as intraoperative monitoring. Now as I understand this is a technique that you're beginning to use, and most spine surgeons are beginning to use, when you're doing spine surgery near the spinal cord, you're beginning to monitor a patient's spinal cord so that you can tell the minute that something happens that may put the spinal cord or the spinal nerves at risk. Now that's my understanding. Can you explain a little bit about what this new technique is and when it's appropriate to use.

Dr. Carter Beck: Well, you know, Randale, there have been a lot of fads in spine surgery over the years, various bells and whistle, gimmicks, procedures which come and go, adjuncts to surgery. Intraoperative monitoring has been around for a long time and used in various capacities and for various reasons, usually focusing on the spinal cord in particular. Recently the scope and frequency with which we were employing intraoperative monitoring has expanded quite a bit and we believe it is an important part of good spine surgical technique and not a fad, and not a gimmick, but something that really is helpful to the patients and to their surgeon. One of the problems in dealing with really all neurosurgery, and in this instance spinal surgery, is that when a patient is on the operating table anesthetized, the physician loses feedback from the target organ which, in this case, is the nervous system, central to peripheral nervous system, and so they are basically guessing as to whether what they're doing is acceptable to that organ and whether or not that organ is going to function properly once the patient is awakened. And so, there has sort of been a time honored thing, a neurosurgery and we'll see when the patient wakes up how we did which is different, I think, then say a heart surgeon does. They get pretty instantaneous feedback about how they're doing because there is bleeding, and sometimes very impressive bleeding, and that tells them a lot. They can monitor the blood pressure and that really is giving them instantaneous feedback from the target organs. So, in spine surgery, what we have done for years, but now do, I think, as a rule very regularly on almost every case, is to monitor the function of an anesthetized patient's nervous system, and that can be done in a number of ways. The easiest way is just to do what is called EMG or electromyography. If you stick a very small needle into a muscle group, you can monitor impulses from nerves that go to the muscle group. So, for example, if a surgeon is operating on somebody's lumbar spine and the muscle group starts to twitch, it may be that he's putting too much pressure on the nerve in the course of trying to, say, take out a herniated disc or reconstruct the spine. So, over time we have found that this is very valuable for a surgeon. It gives a surgeon, if nothing else, a lot of confidence that what they're doing at a given moment in time is okay, and if they do something, which is irritating the nerve, they found out quite quickly.

Dr. Sechrest: A couple of questions. One, my understanding is that, like you say, this has been around for a long time but people didn't really use it that much. Do you think that the rise of minimally invasive surgical procedure, where you can't really see; you know, in the old days, we tended to look at what we were doing and now we're doing more things blindly, to some degree, using x-ray control and that sort of thing, so we're not really seeing those nerves. We're not really seeing the spinal cord and, do you think that's putting those nerves more at risk, and maybe that's the impetus for having more spine surgeons, sort of now, using this technology?

Dr. Carter Beck: I think that's part of it, certainly. When you do a percutaneous procedure and the skin is between the surgeon and the nerves it certainly is very helpful to have this kind of monitoring. I think that the technology is also improved. It's now fairly straight forward for us to get this accomplished in the operating room at the level of a community hospital whereas, in the past, this was very sophisticated, cutting edge technology that really existed mainly in academic centers. I think also the tolerance for bad outcomes or for mysterious nerve injuries after surgery is much lower in America today. I think people expect and demand things to be perfect, and this is one way that a surgeon can help to move the ball forward and get closer to that goal. I think that's an idealistic goal, but it certainly is a valid one.

Dr. Sechrest: Well, we currently obviously do just lots of different types of monitoring to try to reduce risk and, as you say, this is one more technique that's available and, if it can reduce the risk at a reasonable cost than it would probably be a trade-off.

Dr. Carter Beck: Right, today with a few electrodes, wires hooked to the patient in a laptop computer, we can get a lot of instant feedback to the spine surgeon about what they're doing and how well the nervous system is tolerating it. So it's something that we took a look at a year or two ago with a somewhat skeptical eye as to whether this was really necessary, as to whether it would be helpful, and we found that it is very practical and very effective, and all of us feel much more comfortable doing the procedures that we do when we have intraoperative monitoring available, and today, the majority of the cases that I do are monitored.

Dr. Sechrest: What types of procedures would you recommend that intraoperative monitoring can reduce the risk? And which types of procedures do you feel are not necessarily serious enough, or the risk is not serious enough, that the intraoperative monitoring extra cost is justified.

Dr. Carter Beck: Well, when I trained, Randale, the intraoperative monitoring for spine surgery was pretty much isolated to working in and around the spinal cord, and we would monitor the functions of the long tracks which go from the brain through the spinal cord and out into the peripheral nervous system, so a spinal cord tumor, which is a rare thing, would get intraoperative monitoring. As I've said, over the last 10 years, the scope has expanded. Currently, today, I do it or try to do it when practical for every spinal surgery, even a simple outpatient microdiscectomy, or one of the most minimal surgeries that I do, I think that it's nice to have, because a part and parcel of a simple microdiscectomy is retraction of the nerve and not every nerve root tolerates retraction in the same way. There certainly are cases, not very common, in fact, rare, where actually the nerve is injured by a retractor, and this is feedback as to whether or not that's the case. Even more importantly, it removes ambiguity. There are some times when patients have a problem after surgery that we don't understand. And the question always arises, "Well, did we do something to the nerve during surgery?" This removes that ambiguity. If the nerve didn't squeak while we were working on it during surgery, the surgery didn't cause it. And I think that that's pretty objective and definite evidence. So as far as I'm concerned right now, there is really no spinal surgical procedure where it's unnecessary and I'm employing it fully in my practice.

Dr. Sechrest: Let me paraphrase a couple of things that you've just said so that I can understand it and I hope the audience can understand it. When you use the term "retracting the nerve root" what we're really talking about it is putting a special instrument on a nerve and pulling it to the side so that you can perform the surgery.

Dr. Carter Beck: Correct.

Dr. Sechrest: In the old days, you didn't know if that was causing any damage to that nerve at that time or not. You had to wait until the patient woke up and you still didn't know whether that caused the damage or what. You just knew you pulled a nerve to the side. What you're saying, I think, is that with the constant intraoperative monitoring, the minute you pull that nerve, if the machine tells you you're pulling too hard you can stop.

Dr. Carter Beck: That's absolutely right.

Dr. Sechrest: And protect that nerve.

Dr. Carter Beck: That's right.

Dr. Sechrest: Before permanent damage occurs. And you can document that as well.

Dr. Carter Beck: Right.

Dr. Sechrest: When you pulled the nerve there was no damage so pulling that nerve with the retractor could not have caused the end result.

Dr. Carter Beck: If there's a problem with surgery, and fortunately they're very rare, but it's very nice for the relationship between a patient and the surgeon for the surgeon to say, "I monitored and I know that what we did was normal, what we did was acceptable. There wasn't any problem there, so we need to look for alternative explanations.

Dr. Sechrest: Now let's talk a little bit about what that means to the patient. You mentioned that you were using small little needle electrodes. I'm assuming that these electrodes are placed after the patient is asleep, so the patient is not going to recognize any difference in terms of the operation by doing monitoring.

Dr. Carter Beck: That's true. Sometimes these days they're actually placed in the preoperative holding area. It's not a very uncomfortable thing for patients, but they can certainly be placed when patients are anesthetized and for the patient I think it's really no change, and for us it's a significant added layer of caution and safety.

Dr. Sechrest: Now one thing patients are probably going to want to know and that is cost. Because this is obviously a level above the norm, it increases the number of people in the operating room that are actually doing this monitoring and, as I understand it, most cases of intraoperative monitoring are actually being monitored by a neurologist or some person who is skilled, that's not in the operating room, but is skilled at reading these scans and watching all the time. The interesting thing about the internet is that, in a lot cases, this is now being done over the internet, where the person actually watching your surgery, reading your printout, is in another state.

Dr. Carter Beck: Right, again. And here's technology helping us out here. It's now we can have an expert reviewing real-time intraoperative EMG tracings or nerve tracings who is a thousand miles away, and that certainly is helpful particularly in smaller community hospitals who might not have a neurologist who can spend their time in the operating room or a skilled electromyographer who can spend the time doing that. So I think this is increasing the scope and availability of this increasingly important technique.

Dr. Sechrest: And in your practice, this is something that you feel like has given you. I think you said that it makes you more comfortable. Do you really think that it has reduced your risk? Do you think that it has improved the outcomes for the patients you've done over the past year?

Dr. Carter Beck: I do think I've seen some benefit. I think it's a small increment. But when we're talking about preservation of the nervous system, any way that we can do better is valid and is important and, yes, there is some cost associated with it. The insurance companies seem willing to pay because they recognize that the patient with a surgically induced nerve lesion is going to cost them a lot of money down the road. It's going to be very costly and so anything we can do to prevent those kinds of things from occurring is valid and is worthwhile I think.

Dr. Sechrest: Any other comments about risks and benefits of intraoperative monitoring that patients should know before they have spine surgery? Any thing we haven't discussed in this segment?

Dr. Carter Beck: I think that some of it has to do with patient's personality. I think that it's important for patients to know that this technique exists and, depending on their personality and their trust in their physician, if they trust their physician or their surgeon and their surgeon says I don't need it, he's probably right. Some patients want every measure of safety that is reasonable and feasible, and this is one of the things that is on the list. And so, educated patients should consider it as one component or one measure of a skilled and multidisciplinary spine program.

Dr. Sechrest: Are there any risks to the patient of intraoperative monitoring that the patient should know about?

Dr. Carter Beck: I think there's really no risk to the patient. Occasionally, a patient can get a bruise in a muscle group from the electrode needle that was placed right before surgery. That's a minor thing. And I don't know that I've ever seen any complication as a direct result of the monitor.

Dr. Sechrest: Thank you very much for this discussion on intraoperative monitoring. I think it's an excellent discussion of where we're headed in spine surgery in terms of reducing the risk to patients, and I think this is a technology that probably is, as you said, going to become the standard of care over the next few years.

Dr. Carter Beck: Yeah, I think it's here to stay. Thank you.