Table of Contents
With the increasing use of computed tomography for screening and diagnostic workup, increasing numbers of patients are found to have pulmonary nodules. The patient in this case presented with vision changes, neck weakness, and dysphagia. Workup revealed non-thymomatous myasthenia gravis as well as an incidental right lower lobe lung nodule that was suspicious for malignancy based on imaging characteristics, interval growth, and history of breast cancer. She required a lung resection for diagnostic and therapeutic purposes. Additionally, a thymectomy was indicated to help control her myasthenia gravis symptoms. Consequently, a combined approach was conducted.
Myasthenia gravis (MG) is an autoimmune disorder in which autoantibodies directed at components in the postsynaptic membrane of the neuromuscular junction (acetylcholine receptors or receptor-associated proteins) result in fatigable weakness of ocular, bulbar, limb, or respiratory muscles. Most patients have detectable antibodies against the acetylcholine receptor or muscle-specific tyrosine kinase receptor.
Patients with MG present with fluctuating skeletal muscle weakness that is worse later in the day or after exercise. Ptosis and/or diplopia is the initial presentation in 50% of patients. A smaller proportion of patients present with bulbar symptoms such as dysarthria, dysphagia, and fatigable chewing and less frequently with proximal limb weakness. When respiratory muscle weakness leads to respiratory failure, this is termed “myasthenic crisis” and is a life-threatening situation. Myasthenic crisis can be precipitated by many factors including medications, surgery, or inflammation/infection.
This is a 69-year-old female with a history of myasthenia gravis, hypertension, diabetes, left breast cancer treated with lumpectomy, adjuvant radiation, and hormonal therapy who presented with a right lower lobe spiculated lung nodule. The patient started having myasthenia symptoms about 1 year prior to presentation. She had diplopia, drooping head, unsteady gait, and dysphagia.
On examination, patients demonstrate weak eye movements with intact pupil function. They may appear expressionless due to facial muscle involvement and have a “dropped head” from weak posterior neck muscles. This patient in this scenario had clear lung sounds bilaterally. She had fatigable bilateral ptosis, right greater than left. She had fatigable left hyperopia in extraocular movements. She had decreased neck flexion strength. The rest of the neurological examination was unremarkable.
The diagnosis of MG can be confirmed by serologic tests for autoantibodies and electromyographic studies. The edrophonium chloride (Tensilon) test is sensitive but has a significant false positive rate. A chest CT or MRI should be obtained to demonstrate the absence of a thymoma. About 60%–-70% of MG patients have thymic hyperplasia, and 10%–15% of patients have an underlying thymoma.
In this case, a chest CT revealed a spiculated 1.3-cm lesion at the fissural surface of the superior segment in the right lower lobe that was highly suspicious for a carcinoma of the lung (Fig. 1). A PET/CT was subsequently obtained that showed FDG avidity suspicious for malignancy.
The natural history of MG is that of progressively shorter symptom-free intervals that peak within 2 to 3 years of disease onset. A period of time then elapses when patients typically have a persistent, stable disease that can worsen in the setting of infection, medications, or other clinical changes. A third phase may follow in which about 10%–20% of patients may have spontaneous remission.
Medical management of MG involves symptom control (anticholinesterase agents) and immunomodulation (steroids, immunosuppression, plasma exchange, intravenous immunoglobulin). Patients with non-thymomatous MG may benefit from thymectomy to improve symptoms or increase the probability of disease remission. The Myasthenia Gravis Foundation of America (MGFA) classification of MG severity suggests that patients with only ocular MG (MGFA I) do not derive benefit from thymectomy whereas patients with generalized MG (MGFA >II) may see symptom improvement.1 An important caveat is that a high percentage (50%–70%) of patients with ocular MG progress to generalized MG over the first 2 to 3 years of diagnosis; thus, early thymectomy may “rescue” a proportion of this population.
This patient had a right lower lobe lung nodule that was suspicious for malignancy and non-thymomatous myasthenia gravis. She required a lung resection for diagnostic and therapeutic purposes as well as a thymectomy to help control her myasthenia gravis symptoms. Consequently, a combined approach was conducted.
Transcervical thymectomy is the least invasive open approach; however, complete resection of perithymic tissue is limited. This is important because the thymus may extend beyond its anatomic boundaries (innominate vein superiorly and phrenic nerves laterally), and about 75% of patients have ectopic thymic tissue throughout the anterior mediastinum. Minimally invasive techniques such as video-assisted thoracoscopic (VATS) or robotic thymectomy result in improved visualization and completeness of resection. They are performed either from the left or the right chest depending on surgeon preference and tumor laterality.
The surgeon should work with the neurologist to optimize the patient preoperatively to prevent postoperative myasthenic crisis and avoid respiratory failure. Forced vital capacity and maximal breathing capacity (frequency multiplied by the volume of breaths in 1 minute) should be measured to assess respiratory weakness. MG symptoms must be well controlled with cholinesterase inhibitors, immunosuppression, plasmapheresis, or intravenous immunoglobulin treatment before operation.
Preoperative planning with the anesthetic team is critical; neuromuscular blockade is completely avoided as patients with MG are resistant to succinylcholine and highly, and unpredictably, sensitive to nondepolarizing agents. Sedatives and anesthetics should be short acting to minimize respiratory depression on emergence from anesthesia. A combination of inhalational and intravenous anesthesia is often used. Other medications known to interfere with neuromuscular transmission should be avoided.
MG symptoms improvement or remission after thymectomy may be seen several years after thymectomy.
Given the expectation of prolonged immunosuppressive therapy for MG, diagnosis of a solitary pulmonary nodule is desirable to exclude specific infection and aggressive neoplastic disease.
A. LUNG WEDGE BIOPSY, RIGHT LOWER LOBE:
Carcinoid tumor, typical.
One lymph node in the wedge resection is involved by carcinoid tumor.
NOTE: The tumor cells are diffusely synaptophysin and chromogranin positive. A stain for ER is negative. Ki-67 stains 1% of tumor cells. One minute microscopic focus of cellular degeneration is present. Cytologic atypia is minimal. No mitoses are identified.
Tumor islands are present in some alveoli adjacent to the nodule of tumor. There is limited lymphangitic spread of tumor but not at resection margin. Margins of excision are free of tumor. A portion of the carcinoid tumor is densely sclerotic.
Some of the histologic features are unusual, but the findings do not constitute a diagnosis of atypical carcinoid tumor. Selected slides were reviewed in conference.
B. STATION 12 MAJOR FISSURE:
There is no evidence of malignancy in one lymph node (0/1).
C. STATION 12 LYMPH NODE BIOPSY:
Metastatic carcinoid tumor in one lymph node (1/1).
D. STATION 7 LYMPH NODE BIOPSY:
There is no evidence of malignancy in two lymph nodes (0/2).
E. THYMUS RESECTION:
Fatty replacement. No thymic tissue is identified.
Thymectomy for MG was first described by Alfred Blalock in 1939 in the case of a young woman with a thymoma whose myasthenic symptoms went into remission after thymectomy.2 In 1941, he further demonstrated that symptom improvement could also be achieved in patients with non-thymomatous MG who underwent thymectomy.3 Thymectomy for MG became a well-established treatment paradigm after the publication of a longitudinal study of 1,355 patients from Mount Sinai and Massachusetts General Hospital.4 This study demonstrated that females less than 40 years old with moderate to severe generalized non-thymomatous MG who underwent thymectomy had significant (38% total remission, 51% improvement in symptoms) and sustained benefit.4
The only controlled randomized thymectomy trial was recently published in 2016. This was a multicenter trial that compared transsternal thymectomy plus prednisone with prednisone alone.5 126 patients were included under the following criteria: age 18–65, non-thymomatous MG, disease duration < 5 years, MGFA class II–IV, and elevated serum acetylcholine-receptor antibody. The thymectomy group demonstrated higher improvement in Quantitative Myasthenia Gravis scores and less immunosuppression requirement over a 3-year follow-up. Questions still to be answered are whether these benefits are sustained over longer periods of time, whether less invasive surgical approaches offer the same benefits, and whether these benefits can be seen without concurrent treatment with prolonged high-dose steroids.
Operative morbidity and mortality for thymectomy is 20% and 1%, respectively.6,7 Need for postoperative ventilation in one comparison study was 4% after VATS thymectomy and 16% after transsternal thymectomy.8 The most recent international consensus guidelines for management of myasthenia gravis recommend that9 (1) for patients with non-thymomatous, generalized MG, complete thymectomy is performed as an elective procedure to avoid or minimize immunosuppressive treatment; (2) all patients with thymomatous MG should undergo complete thymectomy, and incompletely resected thymomas should be treated with adjuvant chemotherapy and/or radiation; (3) less invasive approaches to thymectomy (thoracoscopic, robotic) appear to yield similar results to more aggressive approaches, although this has not been shown in randomized controlled trials.
The patient in this case had postoperative bleeding and was taken back to the operating room on postoperative day 1 for exploration. After adequate monitoring, access, and resuscitation was established, the patient was intubated with a double-lumen endotracheal tube, and the patient was placed in the left lateral decubitus position. The right chest was entered via the previous thoracotomy incisions. About 1 L of hematoma was evacuated. Bleeding was identified at the sternal side of the internal mammary vein. This was controlled with suture ligation. The remainder of the patient’s postoperative course was unremarkable. She is currently weaning off steroids and having improved muscle strength. Final pathology demonstrated typical carcinoid tumor with 1 positive station 12 lymph node. The thymus specimen had fatty replacement with no thymic tissue identified.
Thymectomy is ultimately the most appealing form of MG treatment because it avoids the need for long-term commitment to immunosuppression or steroids. Advances in immunosuppressive drugs and emerging applications of techniques such as hematopoietic stem cell transplantation may be part of MG treatment in the future.10
Treatment for typical carcinoid tumors consists of complete resection and lymph node sampling. A lymph node in the fissure showed metastatic carcinoid tumor. Given her comorbidity, the extent of surgical resection is adequate. Radical lymph node dissection may have been an option for a healthier patient. Observation by computed tomography is a satisfactory management for our patient.
We have nothing to disclose.
The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published on-line.
- Jaretzki A III, Barohn RJ, Ernstoff RM, et al; Task Force of Medical Scientific Advisory Board of Myasthenia Gravis Foundation of America. Myasthenia gravis: recommendations for clinical research standards. Ann Thorac Surg. 2000;70(1):327-334. doi:10.1016/S0003-4975(00)01595-2.
- Blalock A, Mason MF, Morgan HJ, Riven SS. Myasthenia gravis and tumors of the thymic region: report of a case in which the tumor was removed. Ann Surg. 1939;110(4):544-561. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1391425/.
- Kirschner PA. Alfred Blalock and thymectomy for myasthenia gravis. Ann Thorac Surg. 1987;43(3):348-349. doi:10.1016/S0003-4975(10)60635-2.
- Perlo VP, Poskanzer DC, Schwab RS, Viets HR, Osserman KE, Genkins G. Myasthenia gravis: evaluation of treatment in 1,355 patients. Neurology. 1966;16(5):431-439. doi:10.1212/WNL.16.5.431.
- Wolfe GI, Kaminski HJ, Aban IB, et al. Randomized trial of thymectomy in myasthenia gravis. N Engl J Med. 2016;375(6):511-522. doi:10.1056/NEJMoa1602489.
- Bachmann K, Burkhardt D, Schreiter I, et al. Long-term outcome and quality of life after open and thoracoscopic thymectomy for myasthenia gravis: analysis of 131 patients. Surg Endosc. 2008;22(11):2470-2477. doi:10.1007/s00464-008-9794-2.
- Gronseth GS, Barohn RJ. Practice parameter: thymectomy for autoimmune myasthenia gravis (an evidence-based review). Neurology. 2000;55(1):7-15. doi:10.1212/WNL.55.1.7.
- Meyer DM, Herbert MA, Sobhani NC, et al. Comparative clinical outcomes of thymectomy for myasthenia gravis performed by extended transsternal and minimally invasive approaches. Ann Thorac Surg. 2009;87(2):385-391. doi:10.1016/j.athoracsur.2008.11.040.
- Sanders DB, Wolfe GI, Benatar M, et al. International consensus guidance for management of myasthenia gravis: executive summary. Neurology. 2016;87(4):419-425. doi:10.1212/WNL.0000000000002790.
- Bryant A, Atkins H, Pringle CE, et al. Myasthenia gravis treated with autologous hematopoietic stem cell transplantation. JAMA Neurol. 2016;73(6):652-658. doi:10.1001/jamaneurol.2016.0113.
- Overview of Case
- Anesthetic Regimen
- General anesthesia with IV and inhalational anesthesia, no muscle relaxation
- Bronchoscopy to assess for airway abnormalities
- Reintubation with left-sided double-lumen endotracheal tube
- Radial arterial catheter placed for blood pressure monitoring
- Patient Positioning and Access Ports Selection
- Left lateral decubitus position is achieved with appropriate padding: rolled blankets support the patient in front and back, pillow between the legs to protect the bony prominences of the knees with dependent leg in flexed position, left arm on padded arm board, and right arm on arm rest. Bed is flexed to provide maximum opening of the rib spaces. Neck and head are maintained in neutral position with additional cushions if needed.
- Right lung is isolated and the chest is prepped and draped in sterile fashion.
- Camera port in midaxillary line facing the slope of the diaphragm (often 9th intercostal space); accessory port in posterior axillary line at the level of the fissure (5th intercostal space)
- Utility thoracotomy anterior axillary line (5th intercostal space anteriorly); wound protector placed
- Visual and palpatory identification of right lower lobe lung nodule
- Dissection of fissure and pulmonary artery
- Isolation of nodule with non-crushing clamp to gain margin by traction
- Wedge resection using thick-tissue stapler
- Inspection to ensure complete excision
- Frozen section examination
- Lymph node sampling, here stations 7 and 12
- Discuss Positioning and Overview
- Right-tilt table to expose anterior mediastinum
- Identify the course of the right phrenic nerve from the top to the bottom of the chest
- Begin thymic dissection separating pericardial fat and thymus from diaphragm and pericardial sac
- After posterior separation, plane between sternum and anterior mediastinal fat and thymus is entered toward left pleura to the safe limits of this position. Lung is re-expanded, and all incisions are temporarily closed.
- Repositioning Position and Camera
- Supine position with roll under the right chest
- Right arm is positioned behind the chest and the chest is prepped and draped in sterile fashion
- The anterior access ports are reopened. Laparoscopic port is used to insufflate the chest to pressures of 8–12 mmHg
- Additional 5 mm access port is inserted in the second intercostal space
- Anterior dissection to separate the thymic tissues from the sternum
- Thymus dissection off of contralateral left pleura, avoiding left phrenic nerve
- Separation of thymic tissue from pericardium and innominate vein
- Dissection of the plane anterior to innominate vein and division of thymic veins
- Division of internal mammary vein and exposure of cervical thymus
- Dissection of thymic tissue from neck and division of vascular attachments to cervical thymus
- Placement of specimen in bag and orientation for permanent section
- Chest Tube Insertion
- Ensure Hemostasis
- Lung Reexpansion
- Close Incisions and Access Ports
- Close overnight monitoring of respiratory status
- Chest tube is usually removed on postoperative day 1. Please listen to our comment regarding postoperative course and pathology in this patient.
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.
This is a fairly unremarkable bronchoscopy. Again, no secretions. Good. So we’ll proceed with double lumen intubation.
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.
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.
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.
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.
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.