PREPRINT
226 views

Wedge Resection of the Lung and Thymectomy by Thoracoscopy

Henning A. Gaissert, MD, Lucia Madariaga, MD
Massachusetts General Hospital

Transcriptions

CHAPTER 1

Welcome, I'm Henning Gaissert. I’m a thoracic surgeon at Massachusetts General Hospital, and today I would like to show you a combined lung resection and thymectomy. The patient is a sixty-nine-year-old woman, and she was found to have myasthenia gravis - about six months ago. When Pyridostigmine alone didn't work, she was treated with IVIG and plasmapheresis to avoid systemic immunosuppression. However, when I saw her two months later, her neck weakness had worsened, she was unable to keep her head straight, and so she then was started onp Prednisone and CellCept. And on this combined treatment with additional IVIG, she normalized her forced vital capacity from eighty percent of predicted to ninety three percent of predicted, and she became stronger and was able to sit - sit in my office and looked me in the face, and she was able to swallow without problems.

She has a right lower lobe lung nodule. Let me show you the CT scans. It is very close to the superior segmental bronchus, which is here, and you might consider this a good candidate for superior segmentectomy, but when you look closely, the nodule is really at the border between superior segment and basal segments, so that the distance between the nodule and the lower lobe artery was only thirteen millimeter. It was close.

So the questions which we face now is how to remove the nodule and make a diagnosis. I should mention that it was evident on the PET scans so that at least there's a possibility that this is lung cancer. And then we will first start a procedure that is mostly in back of the chest, and through the same approach, begin a procedure that's - thymectomy - that’s usually conducted through the anterior chest, and that will be really where it is interesting - how to organize your access ports for first the lung resection and then a thymectomy.

Xiao Dong, so this patient has difficult to control myasthenia gravis. She's on Prednisone, she's on CellCept. I have not quite decided whether I just want to do a wedge section or a lobectomy, considering the risks. What is your plan for an anesthetic management?

I think like you said, this patient has a very bad to mild myasthenia gravis, hard to control by medication, and from my point of view, we’re trying to minimize the muscle relaxant from the medication, so we’re going to general anesthesia without giving her any muscle relaxant. We’re going to use primarily remifentanil to initiate and maintain anesthesia. And in the meantime, we will give her some inhalation agent which will give you some muscle relaxation in fact during the surgery. At the end of the case, we can just use some ventilator to get rid of isoflurane and to help the muscle function to return.

So your plan is for mix of total intravenous anesthesia and inhalation, and our plan is to extubate the patient immediately after the procedure.

Yes, that’s what we’re aiming for. We're trying to take advantage of each medication and avoid the disadvantage of each medication.

Good. Let’s get going.

That’s right.

This is a fairly unremarkable bronchoscopy. Again, no secretions. Good. So we’ll proceed with double lumen intubation.

CHAPTER 2

For the first part of the procedure - the lung resection - the patient is in left lateral decubitus position. We have a roll on either side to keep the patient in place. The arm is out of the way. It's not as critical for lower lobe resection, but for an upper lobe resection, I like to have incisions high up. For the lower lobectomy, it could be lower. And this procedure would not be really conducive to a thymectomy, but that's not really our focus of attention at the present time.

We are in left lateral decubitus position. The only access port that is determined from the outside is there one for the camera, and that I place according to where I believe the diaphragm this and the dome of the diaphragm. So my estimation of where the dome of the diaphragm, based on her built, is - is somewhere here. And so I'll be below the dome of the diaphragm, but still low enough for a procedure on the right lower lobe.

Incision. Just incise into the fat. Do you have a straight snap please? Can I have a knife? Over - yes. Camera. Do you have the igloo? This device is supposed to replace hot water. It doesn’t quite work as well, but we’ll accept it.

So lung is isolated. The lung looks normal. We are at the base of the diaphragm. The first incision that we place is a - it serves a retraction of the lung. And it will not be useful for any later anterior mediastinal procedure.

So let's count the ribs. First rib. Second rib. Third rib. Second rib, third rib, fourth, and fifth. My preference for a lower lobectomy is to have an - a utility thoracotomy in the fifth intercostal space. That may at times vary, but for her, it looks like this is an appropriate incision. Pen please.

Do I add this point think about the later procedure? I don't, but I believe that this incision will have some usefulness during a thymectomy. And we will again anesthetize the intercostal muscle bundle. Knife. And now I’ll take the cautery. Can I have the DeBakey please? Thank you.

I’m helping Dr. Lucia Madariaga who is a fellow in our residency. And I hope that I’ll be a good assistant.

The nodule should be visible on the fissural surface of the lower lobe. Is that it? And it is. And what is immediately visible is it's close to the fissure. It is not really in the superior segment. It is at the border between superior segment and basal segments. What’s the cautery on? 30/30. And use a little bit of hot and cold dissection. Stay as far away from that lesion as possible.

Use hot and cold, so now use cold dissection so that you don’t have to use the cautery right on the vessel. Okay. Dissect cold the artery. And dissect a little further - cold. And - it’s very thick, no? Should we go through this stuff? Keep on going. Through the lung? Yes. You think over here, or still over there? Taking it with us - yes. Can you tilt the patient posterior - towards me please. Tilting towards you. A little bit more? Yes - yep. Any interest in taking that now? I’m sorry? You going to take the lymph node now or with the specimen? Use a cautery. And don’t pass point because the pulmonary artery is right behind it. This is station 12, major fissure, and will be sent when we have a specimen.

Open widely. A little bit closer to the nodule - yes, now. Closer? Close, close. Good. Articulation is off. Good, now close. It’s closed now. And now, hang on a second. We want to see first. So we are right on the pulmonary artery, but - but we're not in the pulmonary artery, and so why don’t you staple now - fire now? Yes. And then a second staple line please.

I have - a very sharply demarcated lesion. Does not look infiltrated and could be just benign.

So a carcinoid tumor is being suspected by the pathologist, and as part of a surgical treatment for a suspected carcinoid tumor, I would like to sample further lymph nodes. There's a second lymph node here in the - in the fissure. And Lucia, why don’t you go ahead and dissect out this lymph node? Can I have a DeBakey? Grab it now? Let go. We will now expose the subcarinal lymph nodes to sample a representative subcarinal lymph node.

It is not my habit to use the harmonic for lymph node dissection, during the lung cancer surgery. But since I have the harmonic here, I’ll use it for this purpose.

To expose this area, the patient is maximally airplaned to the left, the whole table is tilted maximally to the left, a retraction is placed onto the lung, and it cannot be seen - it's - it's almost outside the chest - the lung is retracted forward to expose the posterior mediastinum.

The vagus nerve is here. We are in front of the vagus nerve, behind the airway, and a representative specimen of subcarinal lymph node is being dissected. We'll take our time to not risk injury to that the - vagus nerve. That's a specimen for permanent section, station seven.

CHAPTER 3

So now we're looking at the anterior mediastinum. This is not my preferred position for a thymectomy, but I will use the current position as much f - for the dissection until I feel that - that we need to change to a more supine position. The landmarks for a thoracoscopic thymectomy is the diaphragm, the pericardium, the phrenic nerve - of particular importance in a patient with myasthenia gravis - and the anterior border at the sternum as well as the internal mammary vein. We will begin with the pericardial fat.

The extent of thymectomy to accomplish the immunologic goals of this procedure - the minimal extent of thymectomy is unclear. Is it important though to remove these tissues? If it was, we would have to do as - it as - as precisely on this side as on the other side. We will remove these pericardial fat nodules because they are there and they're easily removed, but we will not go over to the other side and accomplish precisely the same extent of pericardial fat excision as on this side.

Now we are struggling with the pericardial fat - let me just see, do you have a long ring forceps? Okay. Then let me just take that long ring forceps and see if it is helpful to… Now, you might work with a short ring. Just to push down the pericardium. We're working with a different position than usual, and so we need to adjust here a little bit what we're doing. If this was particularly difficult, we could leave it until the patient is repositioned.

Now we change to work along the - phrenic - phrenic nerve. So, yes. The first - what first you’re going to do is incise the pleura about in that line going up, yes. And at a distance where you know the phrenic nerve is away. It's okay to use the hot stuff now? If you cannot see the phrenic nerve, you cannot work. No, I would switch to a Snowden-Pencer. Can I have a Snowden please? Thank you.

We’ll follow up this line clearly anterior to the phrenic nerve. Scissors please. The harmonic scalpel is a bit sticky - it doesn’t easily advance. Pull back the camera. Thank you - that works. This is the region of where I would expect the thymus. Here I want to dissect over to the other side. I would like to identify the contralateral pleura at a point - at a distance of the innominate vein because at the level of the innominate vein, the contralateral phrenic nerve is going to be close to the area of the dissection.

And at some point I have to determine whether I should switch the position or continue, and at the present time, we're still making good progress. We’re seeing the structures that we need to see. The anterior dissection I will not start. No, forceps sponge - ring forceps. At this time, if I struggle, I would also struggle with a - with a patient in supine position.

No, look up higher. I'd like to return to that area of dissection. Want me to grab that? Yes, if you could. Just gently, put a little bit of traction on it. And now, look up here. We are in the prevascular plane, and as I’m dissecting, I'm just waiting for the time when I’m - when I feel that I should switch to a different position. At the present time, I can still see well.

This is the internal mammary vein. Here's the superior vena cava. I expect the innominate vein to come - to cross in this area. Here's the phrenic nerve. The contralateral phrenic nerve I expect to be in this location. I cannot see it, and I will at this point determine whether I will begin the anterior dissection, and I can do it from below in this area. Can I have suction please - thanks.

I am anterior to the pericardium. I’m now approaching a point where I will see the contralateral pericardial fat. I will not be able to completely dissect it, completely remove it. Can you come a little bit closer? Yeah, thank you Lucia. But in this area, I will remove as much of the contralateral pericardial fat I can - as I can easily see, and unless I were to explore the patient on the other side, I don't think I could accomplish a complete resection of all pericardial fat from this side.

And in this position, the pericardium is not moving away much from the sternum. So for this reason - and we can also not use positive pressure and pneumomediastinum - I’m getting to the end of my dissection that I can accomplish through this approach. Can you show me the area above? So I cannot distend this space, and I can see over to the other side, but I would like to have more - more visualization. And I think at this point, I determine that I will change my position.

To summarize, at this point of the operation, we've removed a carcinoid tumor with a wedge resection. We've completely excised the lesion. We don't have a particular margin, and assuming that this is a partic- this is a typical carcinoid tumor, I would not-perform any further lung resection. We've sampled lymph nodes in the subcarinal space and in the fissure. We then began our dissection to remove the thymus in the anterior mediastinum. We’ve separated the planes between thymus and pericardium. We have begun our anterior dissection, but at this point, we change position to get a favorable exposure of the innominate vein. Thank you.

CHAPTER 4

So we've changed the position of the patient, and we have her in a supine position with a roll under the right chest. The arm is supported, and we've taken great care to take a look at the shoulder - that the shoulder is not to brought back too far. The neck is prepped and the anterior mediastinum is prepped, and this is a change in the position from before. Thank you.

So we have inserted- we have inserted the camera through the original camera port. This original camera port although we have not placed it quite as posterior as I normally would for a lower lobe procedure, is posterior in relationship to the anterior mediastinum, and whether we will be happy with that exposure, we will see shortly. This is a 45 degree optic, and so we'll see how well we get along. I will now insert a port in the second intercostal space and that port will help me with the dissection at the innominate vein.

So because we have - we have our ports in different positions, we have to feel our way to the exposure of the anterior mediastinum. Usually, I have an even more anterior port just above the diaphragm that is not in place now, and through that port, I would have had difficulty seeing my lung resection. And so I have to first gain some - gain some views to see how well this can be done from this exposure. And this is 8 - the pressure of. Yes, please do. And then we need to watch how well she tolerates that. And then whether 8 - pressure of 8 is enough.

I will not continue the anterior dissection to the vein, and I have not yet with these access ports seen sort of the comfort level that I usually have during this procedure. Slow and deliberate in my dissection. There's bleeding, and we'd like to see that from a different perspective. Thank you.

This is the plane anterior to the thymus, and anterior to the innominate vein. Can you center the internal mammary vein? Thank you. Can you take a more lateral view of this? Yeah.

So I will now look for the relationship of internal mammary vein and innominate vein. The advantage of dividing the internal mammary vein is that the plane to the innominate vein is more easily seen and that the innominate vein can be displaced posterior. Can you send you center the innominate - the internal mammary vein, please? Thank you. Come a little bit more close.

So we’re now exposing confluence of superior vena cava, innominate vein, and internal mammary vein. And in this area, I need to suspect a thymic vein. There’s too much tissue, and it’s not completely dissected yet. Do you have an endoscopic peanut? Thank you. Dissection.

It is clear that the ports are more posterior than usual, and I will tolerate that as long as it doesn't affect my ability to reach the goals of the operation, but at some point I may just establish additional ports if I'm not happy. There’s the lung - contralateral lung - I believe, right? Okay, I’m pressing.

We are struggling here but - and the reason we are struggling is that we have a posterior view of the anterior mediastinum and that restricts the approach to the contralateral pleura. And so, we will consider adding an additional camera. No. I don’t see a pneumothorax. That's the pleura on the other side, right? That’s the pleura on the other side, yes. I think the reason that it pops up is at some point it overcomes the positive pressure and it inflates, and the inflation is done with a pop. So you’ve basically got the left side of the thymus already. Well, not in its most critical portion, because when you look up - yeah - see, we are not - we don’t see it where we need to see it most.

Okay now let's look forward to the other side. The camera will give me an anterior look, improve my anterior exposure, and it will be more difficult to do the posterior part, so, I will work on the posterior part first. Can you come a little bit closer? There is a vein, do you see that? And these tissues that go behind the innominate vein - I need the suction. We are fighting, right?

So this is a- an additional port. Do you have a knife please?

So the more anterior, smaller camera - this is a five millimeter, thirty degree endoscope - gives me now a view to the other side. There is a pneumothorax on the contralateral side, and we will now dissect and separate from the contralateral side. By retraction, we will now aim our dissection anterior to the prevascular plane. Can you - what is the pressure right now? Zero. Why - can you change to high - high inflation? Immediately, you see better.

So it does make a difference. If you've noticed, the resupply of the positive pressure now makes it easier to see the lung, to see the pleura. Do you have a peanut please? Look over here. Good, so… The division of the internal mammary vein now provides some improvement of the exposure. There's a vein here back to the thymus - from the thymus to the innominate vein and I’ll start dividing it. Okay here it is possible that there is thymus behind the vein. I don't see it, and so rather than dissecting behind the vein, I will divide these attachments. This is a critical view so that we see here the attachments and the venous branches entering the innominate vein.

So I'd identified this vein here as the internal mammary vein. Behind it, this here - thank you. But I may be mistaken. And this is the real internal mammary vein. It is quite stout, and before considering to divide it, I would like to see it better. It will need to be treated with the harmonic scalpel over a longer distance. I now receive better the innominate vein. The question is are there meaningful branches up? There could be - there’s one there. Here. This is not part of the thymus, but it is part of what provides exposure to the thymus.

So the other side - how far to dissect? The thymus has two cervical extensions - right and left. I believe that this is the left sided extension, and so we are quite close to the end of our dissection here. Below the innominate vein, I don't know whether I've completely dissected this area, so I need to take a closer look here in this region. Lucia, what do you think that is? Vein branch? It could be - what else could it be? Come close. A nerve? What’s that - a nerve, yeah. And so we don’t want to go beyond it, and I don’t think I need to divide it.

What I will do now is so look anterior. This could be the contralateral nerve. Vein - internal mammary vein is over there. We are dissecting here. So this is the plane that will take me into the - into the neck, and a little bit of a distance now. We will now follow these two cervical extensions - the cervical horns of the thymus. The thymic fat is now here very poorly defined, and it starts to bleed - let’s go somewhere else. I would rather compromise on my thymectomy than being too close to the contralateral - phrenic - phrenic nerve. And so I will dissect these tissues. Internal mammary vein is here. This is the plane of the internal jugular, and we want to stay on our side. These are lateral attachments of the left cervical thymus.

Okay, let’s look from the other side. We are left with the disconnection of the cervical thymus. Come in a little bit closer - there is the branch that we talked about earlier. Yep. We are following the cervical thymus now upwards into the neck. The left cervical thymus is usually longer, and it doesn't disappoint us this time. It goes way into the neck. Really, visualization depends on around the entire thymus and seeing the tissues from below and fr - from the front.

On the right side, I cannot discern any more thymus. I’m not lateral to the trachea - I’m anterior. This is the highest extent at least on the right side, and then I'm going to follow this a bit longer on the left, but I think we are as high - close to being as high as possible.

Here I divide the end of the left cervical thymus. I've pulled down the thymus, and I'm confident that I have completely removed it. This is the entire specimen. Let's inspect the resected space.

I performed a wedge resection of the lung, so I will leave a true chest tube in there. If I had not done a lung resection, I would leave a - a usually a 19 French Blake drain but some sort of flexible drain that is mainly made for fluid. We’ll create an opening in the pleura so there is communication between the two pleural spaces. The innominate vein is here. It is pretty much skeletonized. The space anterior to the vessels in the neck is - is freed of any tissues. I don't think that this is thymus, and I will not go there because this will take me lateral to the trachea and into the vicinity of the recurrent laryngeal nerve. We have separated ourselves from the phrenic nerve on this side clearly so as to preserve and not endanger that nerve.

Let's look over to the other side. Here, I disconnected from the pericardial fat on the other side. While you can make an argument that this is not a complete pericardial fat resection, I agree with that, and yet I will draw the limit here. And the tissues in front of the pericardium are completely removed. The specimen will now be extracted from the pleural space, and we will reopen our utility thoracotomy. While I was showing you the anterior mediastinum, the positive pressure had been disconnected, so this is really a true view without any insufflation.

This is the removed gland, and it's - it is not a hypoplastic gland. The gland does not look enlarged. It is not very impressive. This is - this is the pericardial fat on the left. This is the left - this is the right cervical horn. This is the left cervical extent of the thymus. And this is the specimen. You can send that please to pathology.

CHAPTER 5

I think this con - concludes the procedure. A chest tube is inserted and that’s it. Do you have that chest tube? Ring forceps - oh, yes, it’s there. That’s great.

Let’s inspect here. Is there any bleeding? No.

The patient whose operation you just have seen developed bleeding from the chest tube on the first postoperative day. During my re-exploration, I found bleeding from the divided sternal end of the internal mammary vein. I encourage you to review that part of the operation again. This was controlled with a suture. The patient required transfusion. Thereafter, her postoperative course was uneventful.

You may have noticed that one of the lymph nodes contained metastatic, typical carcinoid tumor. I intend to observe this finding. I'm satisfied with the extent of resection. Should lymphadenopathy develop at a later time, I would consider re-exploration for lymph node dissection.

The patient remains on a weaning dose of Prednisone and CellCept. Her symptoms have neither improved nor worsened three months after the operation.

CHAPTER 6

The operation overall went quite well but though we struggled a bit. I think where we struggled was using posterior access ports for an anterior mediastinal dissection, and so we had to revise midstream on how we approached the anterior mediastinum. But let us first talk about the lung resection. I think it's important when there's a lesion that one would like to remove close to the fissure or close to important structures, that these important structures are then completely dissected - that you don't even look at that nodule until you have completely separated the fissure. And that was helpful later on because we started out saying, "oh no, this wedge resection cannot be done," yet we eventually ended up doing a wedge resection. And it was not the most - the nicest wedge resection for a tumor, but it was a complete excision of a carcinoid tumor. What was your impression Lucia?

I did, I thought we did a safe, good operation that adequately addressed what the patient needed.

So in addition to the wedge resection, we also sampled several lymph nodes. What will be the consequence of that, I guess will depend on the final pathology. It's unlikely that we'll have to re-intervene, but she is left with a full set of lobes, and she didn't need to heal a segmental or lobar bronchus. That is also important given her immunosuppressive therapy.

Part of the thymectomy through a posterior incision - through posterior access points went quite well. The separation between thymus and - and - pericardium went well. I think when you do a thymectomy in the presence of myasthenia, you need to take extra caution about the phrenic nerves, and you just need to demonstrate to yourself by having appropriate distance to the phrenic nerve that you don't impair its function. Because it’s devastating to have a patient with myasthenia gravis end up with phrenic nerve paralysis. And we don’t know yet because she is still asleep but in the process of waking up.

Then the dissection around the innominate vein, and when I now lead fellows through that dissection, I find it most difficult to cede control of that part of the dissection. And you probably have seen me do resections before and you probably noticed that I was a little bit on the tense side, because it's very important that the innominate vein is completely visualized and that the branches of the thymic veins that they are carefully separated so that you don't get into bleeding. So then you have to use all the - all the mechanisms that you can to help yourself, meaning increase the pleural pressure, expose the anterior mediastinum better, place the patient in a reverse trendelenburg position so that the innominate vein empties well, and take your time with separation of thymus and - and left phrenic nerve. And then, as I said, I'm not entirely happy about leaving so much pericardial fat, but I think this is a total thymectomy but not a complete excision of the pericardial fat. And that's where we left the patient with some fat, but to completely remove it, we would really have to go over to the other pleural space.

What are your concerns about the postoperative period, Lucia?

Well, postoperatively, right now we're in the process of waking the patient up. I want to make sure she has a good respiratory status. We’re going to be keeping her in a more monitored setting in the recovery unit overnight so we can have one-to-one nursing and monitor her hemodynamics. Second of all, we're going to be in touch with her neurology team to make sure that we are appropriately treating her for myasthenia and to watch out for a myasthenia crisis. And then we need to continue her on her Prednisone and her Cellcept, and we make sure that she's not suffering from adrenal insufficiency.

When would you expect a myasthenic crisis to occur?

I'm not sure actually - within the first 24 hours?

Not sure? If it is related to drugs that we have given, then it would probably be very soon in the first 12-24 hours, but it could also occur that after 2 or 3 or 4 days she becomes increasingly weak.

Now, she has bulbar symptoms - what are we going to do about that? Would we give her something to drink now?

No, so right now we have her restrict-nothing per mouth because we're concerned about her swallowing and aspiration precautions. So we’re going to make sure she has intact neurological function before we allow her to drink.

Yeah, and then we call our friends from the speech therapy department, and it's important that this is a multi-modality and and a multi-service involvement and that everybody is involved and knows what - what their - what their role is in the post operative care of this patient.

Comments



You must be logged in to comment.
Join The Conversation