Hello. My name is Andrew Chang. I am one of the thoracic surgeons at the University of Michigan in the section of thoracic surgery and this is part of the massive open online course, the MOOC, for thoracic oncology. I'll be talking today about chest wall resection. And just to jump into the lecture, we'll start out with a pre-lecture question. So, this is a scenario that we see commonly in thoracic surgery. Which treatment is most appropriate for osteoradionecrosis of the chest wall? So, that's when someone comes in with an exposed wound. And you can often see rib muscles and how do we treat this. So the options for treatment are A, long-term intravenous antibiotics, B, resection with mesh-methacrylate and you'll learn a little bit more about what that is in the next few minutes. Hyperbaric oxygen therapies sounds cool and then, D is resection with pedicled myocutaneous flap. And we'll go over the answers at the end of this lecture. So, some of the objectives for this talk will be to review the reasons for chest wall resection. I touched a little bit on it, just with the introductory question. I also tried to describe the basic tenets of chest wall reception and reconstruction. The outline, we'll talk about is chest wall anatomy, some of the basics. I won't try to get too detailed but we'll talk some about that reasons, or indications that is a medical term for reasons for operation. Chest wall resection, techniques for stabilization, so how once we take out the lesion, the mask, whatever it is that we're cutting out. What do we need to do, what should we do in terms of stabilizing the chest wall. Options for soft tissue reconstruction. So once the chest wall is stabilized, then what do we do after that? And then I'll touch a little bit on outcomes. I don't think I have any slides but I'll talk a little bit about some of the outcomes. So chest wall anatomy. This will be just a very basic introduction to the anatomy. It's fairly straightforward. This is the scanatic taken from the source seen at the bottom of the screen. Basically, you have the chest wall which consist of skin, the muscle layer, fatty tissues. And then, when you get down to the actual chest wall, it consist of the bony portion which includes components such as the sternum, the manubrium as well as the ribs themselves. The ribs are on front have what's called the cartilaginous portion and then the bony portion. And then there's the intercostal muscles that run between each of the ribs. And so this area is what we consider the chest wall. So again, the rib cage and sternum. The thoracic vertebrae in the back. Which provide support as well as connective tissue such as the muscle or cartilage intercostal muscles. And when you get deeper down, so take a portion of the rib on the side here. So you have the intercostal muscle, the rib itself, and then beneath that run the vessels. So there's a artery vein and then a nerve that runs beneath the rib That's what we called the intercostal bundle. And that's an important thing to think about because the nerves for each of the ribs can be pretty painful when they're cut. And so we're to pay attention to how we manage those nerves as well as the vessels when we're performing reception. Deeper to the actual chest wall then our the it's a pleural lining so this is the lining of the lung. So this is the outer pleural lining called visceral pleura. This isn't the actual pleural cavity which is what we called potential space. That is it's not truly a space but fluid and air can build up in that area and then sorry this is the parietal pleura on the outside and this is the visceral pleura on the inside that is the pleura That lines the run itself. But we'll really focus on the chest wall and the ribs. So what are the some of the indications for chest wall recession, lung cancer is the primary indication. So when there's a tumor in this instance here in the left upper lobe of the lung, it can unfortunately sometimes erode through the lung through the plural space and into the adjacent rib space. And so, when we consider doing an operation, it's important to try to get out the tumor in its entirety and not disrupt any of these tissues here. Because by disrupting the tumor, you could potentially allow a spread of cancer into the chest space. That's one reason for chest wall reception. Here's another example for a primary chest wall tumor. So sometimes instead of tumors arising from the lung itself, they can arise from any of the tissue components that I described in the anatomy. So you can have bony growths of the chest wall, bony growths. The bony growths would be called an osteosarcoma typically if it's malignant or osteoma if it's not malignant. Chondrosarcomas would be malignant of the cartilaginous portion of the chest wall. And then there are the very soft tissue sarcomas. So in this case, this is a primary chest wall tumor, you can see over line, there's masculature. So this is a cat scan of the chest where basically taking across section of view of the chest. So you can see the great vessels, tumor itself is pretty close to the breast bone here to the sternum and as well as involving the ribs. In this instance, ion any instance resecting a chest wall, it's important to remove the tumor which you can see here. But also to get an adequate margin around the tumor. And that's typically thought to be anywhere from two to four centimeters around what you can feel. So this is an example of the surgeon removing not only the tumor itself but the adjacent's sternum as well as the ribs attached and the over line muscle, musculature and soft tissues. So again the reasons for operation include primary lung cancers. That is cancers arising with in the lung itself, primary or even metastatic chest wall tumors. Sometimes breast cancer sometimes other types of tumor can migrate into the chest wall and if those are the only areas of cancer or of malignancy then a chest wall recession can be indicated. Also patience can have infection and radionecrosis, so the most common scenario would be if someone has had a previous breast cancer and they receive radiation therapy to the chest. Even though the design has tried to minimize injury to the surrounding structures, it's not uncommon where over time over many years the tissue overlying the chest wall can break down and become ulcerated and eventually expose bone. And that's what we call osteoradionecrosis, and sometimes tumors can arise in that area. So when we're trying to resect again, the key is to remove all devitalized or involved tissue, particularly for osteoradionecrosis. And then prevention of flail chest. So the chest is basically a rigid structure and when your move a significant of it, if you're taking out two or three ribs even a portion of the sternum there's a potential that the lungs won't work as well. And so part of the goal of reconstruction is to re-established the chest wall domain and then at the end provide soft tissue coverage. So, going back to that example, in this instance the surgeon chose to use basically a rigid material, Marlex and mesh. So basically you're taking two layers of mesh and putting in a moldable cement in between to try to reestablish the chest wall domain. And then there's sutures along the edges that securing the mesh over to the adjacent rib or sometimes you have to draw a secret holes into the sternum in order to secure the mesh. In this provides some more rigid structure to the chest wall to prevent flail lung. The other ways of doing this will be to use more flexible mesh, something that's called Vortex, often used in jackets but also a lot in surgery. And there we used thick mesh, usually about two millimeters thick, to recreate the same sort of chest wall domain. Now you can guess, you might surmise that with all this exposed foreign body there's a high risk for recurrence if all we did then was to try to bring the skin together over this coverage. And so the other aspect in terms of how we stabilize things, we use the meshmethacrylate. More recently there have been reports about using titanium alloy ribs to try to recreate the chest wall domain. That's still fairly new but who knows w ith 3D reconstruction, 3D modeling and we might be able to build alloys that might be less bioreactive than some of these foreign bodies. And then once the mesh or titanium rib is placed, how do you cover it? So there are basically four options. One is what's called an advancement flap where we're essentially moving muscle keeping it on its blood supply. So the best examples would be something like the pectoralis major which is one of the anterior chest wall muscles and using that to cover the space. We can also use omental flap. That is we take fat from the abdomen and bring it up over the chest and cover the exposed areas and often will used what's called the pedicled rotation myocutaneous flap. Long term basically we're taking muscle from different part of the chest. Where keeping it's blood supply intact. And then rotating that muscle as well as the overlying skin to fill any soft tissue defect and might be created from a chest wall reception. So best examples would be so one of the chest wall muscles that gets rotated from the back towards the front. Other rotational flaps might be from the abdomen, so what's called using the rectus abdominis. The muscle from the front of the abdomen can be rotated on its blood vessel up into the chest. This one is in the instance that was discussed earlier today in the presentation. That would be difficult to use because the blood vessel for such a rectus abdominis flap is actually the one that runs underneath the sternum. So, if you had to take out part of the sternum, usually we'll take out the blood vessel that runs underneath the sternum, the internal thoracic artery or the IMA, the internal mammary artery. Those are one in the same and that is usually used for that kind of a rectus abdominis flap. So, in that instance, you might want to take the Contralateral the opposite side, rectus abdominis, and essentially flip that up and over to cover the soft tissue defect. And lastly, for really difficult reconstructions, any of these options and the muscle groups like the laticimus or the rectus abdominis can be taken as a free flap. So there you're actually preserving the muscle, the overlying skin but there you're actually cutting the blood vessels that supply that muscle and taking those and reimplanting those into a feeder vessel if you will closer to the chest. That's a much more complex operation less commonly done but still an option if there's really nothing else particularly in surgery. So, some of the potential complications that can arise from this kind of complicated resection reop and coverage would be wound infection of course. Especially if there's mesh or something foreign body that's been implanted. Seroma is where you have buildup of reactive fluid, particularly in response to foreign bodies so The mesh mephacraly reconstruction is particularly prone to seromas so we'll often leave drains in the area in order to try to build up and prevent any fluid collection. Paradoxic respiratory motion, so that's that flail chest so that's if we don't reestablish the chest wall domain. Then potentially what can happen is that when someone tries to breathe in the chest will essentially collapses down that makes it harder for someone to bring air into the lungs. Prosthetic fracture is if one of those rib stress or if the measurement factor gets traumatized and cracks apart, then that can be possible complication. And those instances if it becomes painful or infected them, you have to go back in and remove the prosthetic. And then come up with some other way reconstructing the chest wall. So basically I've tried to cover some of the different reasons for operation. Some of the techniques that we use, as well as the basic anatomy for the chest wall in terms of taking care of Oncologic problems. So going back to the question which treatment is most appropriate for osteoradionecrosis of the chest wall? Now let's go over the options again. So we have A Long-term intravenous antibiotics. B Resection with mesh-methacrylate. C Hyperbaric oxygen therapy. And then D Resection with pedicled myocutaneous flap. So hopefully you'll have been able to come with the answer already. But I'll go over the different options again. So long term intravenous antibiotics. It's okay for starters But in the end if there's some sort of reconstruction, it's pretty unlikely that anabotics will be sufficient to take care of osteogenesis space of course there's dead bone, dead muscle and open wound and for that, very rarely would anabotics alone would be sufficient Resection with mesh-methacrylate. So resection's appropriate but in the setting of an open wound, using mesh-methacrylate could be potentially dicey because of exposing foreign body to already an infected area. Hyperbaric oxygen therapy. So the concept there is that you have an open wound and possibly by exposing the wounds to high, high oxygen concentration that can potentially be toxic to the infection and potentially promote healing. Most of the times, this doesn't work but might be an option for some who is really not a good candidate for an operation. And then finally the answer for this particular scenario would be resection with the pedicle myocutaneous flap. Assuming that such flaps are available, and that the patient already hadn't many other operations. So some of the take home points from today's talk. Chest wall resection is indicated for locally invasive disease. So that means that if we're dealing with the lung cancer, if you're dealing with sarcoma, that is a soft tissue tumor. Osteonecrosi, we want to make sure that the patient doesn't have signs of malignancy somewhere else in the body. It's a pretty bigger operation. Difficult to get the patients through, difficult for the patients to recover from it, in terms of pain. And just a physiologic insults. So we want to make sure there's no signs of cancer that's spread somewhere else. And we don't want to put the patient through an operation that they don't need if unfortunately the tumor spread somewhere else. Restoration of chest domain and soft tissue coverage are key aspects of reconstruction. So the chest spaces is very important for breathing, for providing protection to the internal organs and so we try to do our best to restore whatever area is we have to cut away. And then cover the area with some sort of good soft tissue option to limit infection. Resection and reconstruction should be considered for both curative as well as palliative intent. So, particularly, for the instance of osteoradionecrosis, I know earlier, in the take home points, I said that we, typically, do not recommend reception for someone who has metastatic disease. But, palliation, in terms of limiting the amount of symptoms, discomfort, osteoradionecrosis is a big problem. And often times a surgical option is the best way to help the patients get back to a normal life. Hopefully, over the last few minutes, you've had a chance to learn a little bit more about chest wall resection, reconstruction, some of the reasons that we do the procedure. Hopefully, this will add to what our courses have been trying to review in terms of thoracic oncology. And I thank you for your time and for participating in this MOOC.
