ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Ann Thorac Surg 2010;89:S2128-S2134. doi:10.1016/j.athoracsur.2010.02.099
© 2010 The Society of Thoracic Surgeons
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Joseph B. Shrager
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shrager, J. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shrager, J. B.
Related Collections
Right arrow Minimally invasive surgery

Supplement: 2nd International Bi-Annual Minimally Invasive Thoracic Surgery Summit

Extended Transcervical Thymectomy: The Ultimate Minimally Invasive Approach

Joseph B. Shrager, MD*

Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, and Veterans Administration Palo Alto Health Care System, Palo Alto, California

* Address correspondence to Dr Shrager, Division of Thoracic Surgery, 2nd Floor Falk Building, Stanford Medical Center, 300 Pasteur Dr, Stanford, CA 94305 (Email: shrager{at}stanford.edu).

Presented at the 2nd International Bi-Annual Minimally Invasive Thoracic Surgery Summit, Boston, MA, October 9–10, 2009.


Dr Shrager has no conflicts of interest to disclose.

 

   Abstract
Top
 Abstract
Introduction
 History
 Indications
 Operative Technique
 Results
 Controversy
 Acknowledgments
 References
 
The ideal operative technique for thymectomy in myasthenia gravis remains controversial. Most surgeons perform thymectomy through median sternotomy; more recently, thoracoscopic and robotic approaches have been described. "Extended transcervical thymectomy" is an out-patient procedure that appears less morbid and costly than other approaches. It allows a complete extracapsular thymic resection. Kaplan-Meier complete stable remission rates after transcervical thymectomy are 33% and 35% at 3 and 6 years (higher including patients remaining on single-drug immunosuppression). The major surgical complication rate is 0.7%. We believe that this less morbid and less costly operation is a very reasonable choice in the surgical treatment of myasthenia gravis.

The autoimmune disease myasthenia gravis (MG) is one of the most common disorders of neuromuscular transmission, and its pathogenetic basis, natural history, diagnostic modalities, and means of pharmacologic therapy are well defined. Significant debate continues, however, over the role of surgery in the management of the disease. At the most basic level, the very effectiveness of thymectomy in MG remains a subject of debate. If one believes that thymectomy has a role, then one must entertain the next controversial issue: What is the ideal surgical approach to thymectomy? This review will focus upon results with one technique of thymectomy, the minimally invasive approach termed "extended transcervical thymectomy" (TCT).

The Myasthenia Gravis Foundation of America (MGFA) has classified the various surgical approaches to thymectomy for MG into four main categories and several subcategories according to the presumed extent of thymic resection performed [1]. These categories are the following: T1, transcervical thymectomy (including subdivisions T1a ["basic" TCT] and T1b ["extended" TCT], the latter being the subject of this paper); T2, videoscopic thymectomy (T2a ["classic"] and T2b ["video-assisted thoracoscopic extended thymectomy"]); T3, transsternal thymectomy (T3a ["standard"] transsternal and T3b ["extended"] transsternal); and T4, transcervical and transsternal thymectomy. Each of these procedures (with the exception, perhaps, of "basic" TCT) typically allows extracapsular resection of the thymus gland. The operations vary, however, in the extent to which extracapsular mediastinal and cervical fat (tissues that may contain variable amounts of ectopic thymic tissue) are excised. The MGFA Taskforce appears to have created this thymectomy classification with the intention that as one moved from T1 toward T4, there was a progressively greater amount of tissue resection being described. We would suggest, however, that when extended TCT is performed by an experienced operator, the extent of resection certainly equals that which can be performed by any videoscopic approach and may well equal many of the "extended" transsternal operations currently performed.

Outcomes after the various approaches to thymectomy have been reported across many studies in the form of complete and partial remission rates, generally using crude remission rates only. However, as also delineated in the recent MGFA Recommendations for Clinical Research Standards [1], response to thymectomy is most reliably judged by the rate of drug-free, complete stable remission (CSR) reported by Kaplan-Meier analysis. We will demonstrate that the CSR rate by Kaplan-Meier analysis after TCT is similar to results obtained by video-assisted thoracic surgery (VATS) and even to those obtained by the markedly more invasive, "maximal" transsternal-transcervical approach. Further, TCT has substantially decreased morbidity, length of stay, and presumably decreased costs versus any of the other available approaches.


   History
Top
 Abstract
 Introduction
 History
Indications
 Operative Technique
 Results
 Controversy
 Acknowledgments
 References
 
The first recognizable description of MG probably dates to 1877 with a report by Wilks [2] on a patient who died of progressive weakness and respiratory paralysis without autopsy evidence of central nervous system derangement. Clinical understanding of this disorder was furthered in 1895, which is when Jolly coined the term myasthenia gravis pseudoparalytica [3]. The precise pathophysiology of MG was not recognized until the early 1930s when Walker [4] first used neostigmine as anticholinesterase drug therapy. In 1954, Osserman and Genkins [5] devised what became a widely used scoring system for disease severity and they began using pyridostigmine bromide which remains a standard therapeutic agent today.

Interestingly, surgical therapy actually developed before medical therapy. Also of interest is the fact that the first thymectomy for MG was in fact done transcervically. In 1912, Sauerbach removed a 49 gram hyperplastic thymus from a 19-year-old woman using the transcervical approach. This consisted apparently of only an enucleation of the thymus from within its capsule, but the patient's symptoms abated. In 1939, Blalock and associates removed a thymus gland by sternotomy for resection of a mass in the gland. This patient was also noted to experience improvement in her myasthenic symptoms, and by 1944 Blalock [6] had accumulated a total of 20 patients in whom he had performed thymectomy through median sternotomy for MG.

Sternotomy became the generally accepted approach to thymectomy for MG from the 1950s to the 1980s. This was despite (or perhaps partially as a result of) the work of Kirshner and colleagues (1969) [7] and Papatestas and colleagues (1987) [8], who championed a "basic" transcervical thymectomy that, without the benefit of a sternal-lifting retractor and thus with compromised exposure of the mediastinum, likely led to many cases of incomplete resection of the gland. Jaretzki and colleagues [9] in the 1970s established the presence of relatively high rates of extracapsular foci of thymic tissue in the adipose tissues of the mediastinum and neck, and on the basis of this finding they proposed and strongly advocated over many years an aggressive operation, "maximal transcervical-transsternal thymectomy," designed to remove all of these ectopic thymic foci [10].

In 1988, Cooper and colleagues [11] reported a modified approach to transcervical thymectomy which they termed "extended" TCT to emphasize the contrast with "basic" TCT reported by Kirshner and colleagues [7], Papatestas and colleagues [8], and others. Extended TCT involved use of a newly developed, sternum-lifting, self-retaining retractor which dramatically improved mediastinal exposure and allowed more complete removal of mediastinal thymic tissue and extrathymic fat. Since that time, this technique of extended TCT has reemerged as a suitable alternative to thymectomy through larger and more morbid incisions.

Despite the publication of multiple retrospective reports delineating outcomes after the various approaches to thymectomy, it remains highly controversial today which approach is optimal. It remains unknown whether the wider excision of extrathymic fat that is probably afforded by sternotomy or "maximal" approaches actually translates into improved response rates, and if so, whether the degree of difference in response rates is sufficient to overcome the clearly reduced morbidity of the transcervical operation.


   Indications
Top
 Abstract
 Introduction
 History
 Indications
Operative Technique
 Results
 Controversy
 Acknowledgments
 References
 
Although numerous nonrandomized studies have shown improvement in 60% to 100% of MG patients undergoing thymectomy, and CSR in approximately 19% to 58%, there has never been a randomized study completed comparing outcomes in patients undergoing thymectomy to that in medically managed patients (such a study is in fact now ongoing). Further, many feel that even the few cohort studies with matched control groups are flawed. As a result, the American Academy of Neurology in 2000 went no further than to recommend thymectomy "as an option" to increase the probability of remission from MG [12].

Individual neurologists maintain widely divergent opinions regarding the role of thymectomy, but for those who believe that surgery has a role, the available literature generally supports thymectomy in the following patients: Osserman class I or II myasthenics whose symptoms, despite medication, interfere with their lives substantially; and Osserman class III patients between the ages of puberty and 60 years regardless of the effectiveness of medical therapy. Osserman class IV patients, although amenable to thymectomy, generally require aggressive medical management to control symptoms prior to receiving surgery. There appears to be a benefit to referring for surgery early in the course of the disease, as response rates are generally higher in patients who have had a shorter preoperative duration of disease.

For TCT specifically, there are certain criteria that must generally be met. Most importantly, the patient must be able to extend his or her neck to a reasonable extent, as the access to the mediastinum from the head of the operating table is impossible in a patient who cannot extend. This issue makes the operation difficult in some but not all elderly patients. Morbid obesity is also a relative contraindication, as neck extension and also the sternum-lifting essential to the operation may be compromised in such patients. Prior mediastinal surgery is a strong contraindication, and most feel that TCT is also contraindicated in the presence of known or suspected thymoma. It should be noted, however, that as experience with the operation grows, complete resection of small (<3 cm), clearly noninvasive thymomas can be performed with a low risk of spillage, as long as one has no hesitation to convert to sternotomy when needed [13].


   Operative Technique
Top
 Abstract
 Introduction
 History
 Indications
 Operative Technique
Results
 Controversy
 Acknowledgments
 References
 
The operation is performed in the supine position with general anesthesia through a single lumen endotracheal tube. An inflatable bag is placed behind the patient's shoulders and the neck is maximally extended. An approximately 5 cm curvilinear skin incision is created two fingerbreadths above the sternal notch and one fingerbreadth above the clavicular heads as one moves laterally. Subplatysmal flaps are created superiorly from the level of the incision to the inferior border of the thyroid gland and inferiorly to the top of the sternum. Gelpi retractors are then inserted, and the strap muscles are separated longitudinally along the midline.

The superior poles of the thymus gland are located behind the strap muscles; generally the left superior pole is identified first as it tends to be larger, and this tubular structure is dissected cephalad to where it trails off into the thyrothymic ligament, where it is ligated and divided. A 0-silk ligature is left attached to the pole and is critical in allowing retraction during the subsequent dissection. This pole is then followed caudally to the origin of the opposite pole, which is subsequently dissected up into the right side of the neck in the same manner, and a long silk is left on this pole as well. Typically, both superior poles join above the sternal notch, and the thymus then passes anterior to the innominate vein into the mediastinum.

The cleido-cleido ligament is divided next, and the retrosternal plane is developed by digital dissection. The self-retaining, sternal-elevating retractor is then placed. With deflation of the inflatable bag beneath the shoulders, the sternum is maximally elevated, providing open exposure of the anterior mediastinum. Army-Navy retractors are usually placed at the two corners of the incision and tied to the retractor using Penrose drains to pull the skin edges out of the surgeon's view.

With the surgeon now seated at the head of the table working with a headlight, the thymus is next retracted forward and upward (using the aforementioned ligatures left on each of the upper poles), and the thymic veins draining into the innominate are identified. These are sequentially doubly ligated and divided. There are at least 2 and often as many as 4 of these veins. It is advisable to ligate rather than place clips upon these vessels as the space anterior to the vein will serve as an avenue for the remainder of the dissection, and clips are likely to be disrupted during this dissection.

The freeing of the gland and surrounding mediastinal fat is next carried progressively deeper into the mediastinum, largely by blunt dissection carried out under direct vision. The gland and surrounding fat is separated gradually from the anterior and lateral chest wall, the pericardium posteriorly, the pleurae laterally, and ultimately from the diaphragm. The dissection is taken as far as the phrenic nerves laterally. Ventilation is held intermittently to facilitate the view and the dissection off of the pleurae. The tissue to be resected is for the most part bluntly swept off of these structures until it is delivered through the incision. Vascular attachments encountered (for example, small branches of the internal mammary vessels) are clipped and divided as encountered. Dense attachment to the pleural membrane or pericardium can be easily managed with en bloc resection of portions of these when necessary.

Careful inspection of the specimen and the mediastinum for evidence of any residual, unresected thymic tissue is then performed to ensure that complete, extracapsular resection of the gland has been achieved. In rare cases where there is a question, frozen sections may be obtained to assure no residual thymic tissue. If there is a question of having performed an incomplete resection that cannot be reliably completed transcervically, there should be no hesitation to convert to partial or full sternotomy. In our most recent cases (since publication of our series), we have begun to place a 5 mm video camera along the lateral aspect of the incision as described by de Perrot and colleagues [14] to improve exposure in difficult cases. This provides both light and magnification, and perhaps most importantly, it facilitates teaching the operation to trainees.

Prior to wound closure, the dissection planes are inspected for hemostasis. When either pleural space has been entered, air can be evacuated with a red rubber catheter while holding a sustained positive pressure breath prior to completion of the closure. No drains are routinely left in place. Patients are nearly always extubated in the operating room and discharged home a few hours later after assuring a normal postoperative chest radiogram.


   Results
Top
 Abstract
 Introduction
 History
 Indications
 Operative Technique
 Results
Controversy
 Acknowledgments
 References
 
We interpret the published results after extended TCT to suggest that there is no substantial difference in response rates using this technique versus the clearly more invasive and morbid transsternal approaches. Further, in comparing TCT with VATS approaches that are also considered to be "minimally invasive," it appears that response rates are at least as good, and there is no doubt that simplicity of performance, length of stay, complications profile, and costs all favor TCT.

Our recent report of 151 patients undergoing TCT for MG represents the largest published experience with the operation [15] and incorporates our previous report on the first approximately one-half of the patients in this series [16]. The mean age of patients was 42.5 years and 60.3% were female. Mean preoperative Osserman class was 2.3; 21.2% class I, 39.1% class II, 27.6% class III, and 12.2% class IV. Duration of symptoms was greater than two years in 31.4% of patients. At the time of operation, 75 patients were undergoing single drug therapy (pyridostigmine), and 51 patients were undergoing two drug or modality therapy (pyridostigmine and steroids or pyridostigmine and plasmapheresis). The remainder were receiving three or four drug therapy with or without plasmapheresis. On pathologic examination, the gland was normal in 38% of patients, showed follicular hyperplasia in 36%, thymoma in 8.3%, and other pathology in 11%. Mean postoperative follow-up was 53 months, and 97.4% of patients had complete follow-up.

The conversion rate from planned TCT to more extended incision, virtually always a partial upper sternotomy, was 7.9%. Seventy-three out of the last 74 TCTs were performed on an out-patient basis. The total complication rate was 7.3%, with 6.7% of these classified as minor (wound infections, seromas, atrial fibrillation, pneumothorax). The only major complication was a single case of unilateral recurrent laryngeal nerve injury.

Although we agree with the view that response rates after thymectomy are best reported as complete stable responses (CSR) in the form of Kaplan-Meier analysis, for the sake of comparison with previous studies we also reported our results in the form of crude cumulative response rates. We defined a "response" as a decrease of at least one Osserman class with either less or the same amount of medication, or maintaining the same Osserman class with a decrease in number or dose of medications. By this definition, 80.8% of patients responded to thymectomy. Mean Osserman class fell from a mean of 2.3 preoperatively to 1.0 postoperatively. Crude CSR rate defined as asymptomatic off medication for at least 6 months was 28.8%. When we broaden the definition of CSR to include patients who are asymptomatic but on low dose (< 10 mg prednisone or 150 mg azathioprine) single-drug immunosuppression, the rate rises to 37.1%.

We have felt that this latter, broader definition of CSR is perhaps the more appropriate one given the way our neurologists tend to manage these patients. Despite absence of symptoms for as long as several years after thymectomy, our neurologists are hesitant to completely stop immunosuppressive agents because of reports in the literature of relapses occurring in this setting [17]. Given the minimal morbidity of maintaining a patient on a single-drug regimen consisting of 5 to 10 mg prednisone every day or 100 to 150 mg azathioprine every day, several of the neurologists we have worked with will maintain patients on one of these drugs indefinitely after thymectomy even with prolonged absence of symptoms. Because many patients remain in this category of "asymptomatic-single low dose immunosuppressive" for prolonged periods while additional operated patients will be added to this group over time, the proportion of the entire cohort that this group represents will increase over time. Thus, with increased duration of follow-up, there will be a larger proportion of patients in the asymptomatic-low dose immunosuppressive group and a lower proportion in drug-free complete remission. If one considers only patients in drug-free CSR as true "CRs," then as time of follow-up accrues the CR rate will falsely appear to fall. As we believe it is likely that many of the patients in the asymptomatic-low dose immunosuppression group would remain asymptomatic off of those medications, we believe that they are appropriately included within the definition of a CSR.

More important than the crude response rates reviewed above are the CR rates by Kaplan-Meier analysis after TCT. By Kaplan-Meier analysis, CSR rates are 43% and 45% at 3 and 6 years using our broader definition of a CSR (Fig 1), and 33% and 35% at 3 and 6 years excluding the asymptomatic-low dose immunosuppression group (Fig 2). It is also important to note that no patient suffered a relapse after an initial CSR.


Figure 1
View larger version (22K):
[in this window]
[in a new window]

  		Fig 1. Kaplan-Meier complete response curve after extended transcervical thymectomy using our broader definition of a CR (asymptomatic on minimal dose, single drug immunosuppression). (MG = myasthenia gravis.)

 

Figure 2
View larger version (19K):
[in this window]
[in a new window]

  		Fig 2. Kaplan-Meier complete response curve after extended TCT using the strict definition of a CR (asymptomatic on no medication).

 
Finally, in order to address the concern that CSRs might not be sustained over the long term after TCT due to less complete resection of extracapsular tissue, we separately analyzed the initial 84 patients in our cohort (those operated upon before September 1999), now with further time in follow-up. These 84 patients include the 78 patients in our initial report [16] plus 6 additional patients from that era who at the time of initial analysis were not yet 6 months out from the date of operation. At the time of this reevaluation, this group had reached a mean follow-up of 82 months. Kaplan-Meier CSR rates with this more prolonged follow-up are 44% and 46% at 3 and 6 years, respectively. If we use the more restrictive definition of CSR, this earlier cohort has a CR of 34%, 34%, and 36% at 3, 6, and 9 years, respectively. Thus, CSR rates appear to be preserved over time and even continue to rise slowly.


   Controversy
Top
 Abstract
 Introduction
 History
 Indications
 Operative Technique
 Results
 Controversy
Acknowledgments
 References
 
There is no controversy over whether TCT is less morbid than thymectomy performed by median sternotomy or the "maximal transsternal-transcervical approach." An operation performed through the divided sternum requires a minimum three day hospital stay, and it has a certain implicit rate of cardiopulmonary morbidity and even a small but real risk of sternal osteomyelitis. Such a procedure cannot compete on a morbidity basis with an operation that is performed on an out-patient basis and has a less than 1% major morbidity rate, as documented above.

Some may argue that VATS or robotic approaches are also "minimally invasive" and demonstrate morbidity and costs as low as TCT, but we believe that this is not the case. Transcervical thymectomy does not require even an overnight hospital stay, and patients typically return to their normal activities within a few days. Thoracoscopic and robotic thymectomy, as a result of the need for postoperative chest drainage and pain control for intercostal incisions, typically requires at least a 2 or 3 day hospital stay. All thoracic surgeons have had patients with chronic intercostal neuralgia after VATS incisions, whereas prolonged pain is unheard of after a central neck incision. Beyond the hospital stay, costs for VATS and robotic approaches will clearly be greater than for TCT if reusable ports and instruments are employed.

The real controversy that remains concerns whether the CR rates after TCT versus sternotomy approaches, and TCT versus VATS-robotic approaches, are the same or similar. If one could establish without a doubt that response rates after TCT are identical to those after thymectomy through sternotomy (and presumably, also as good as those after VATS-robotics), then it would be appropriate for TCT to be adopted as the preferred operation. All of the sizeable published studies reporting postoperative response rates, however, are retrospective and without control groups. We are thus left trying to compare results across studies which have enrolled patients widely differing across a variety of important preoperative factors, many of which have been shown to have an impact on response rates. Additionally, as we have discussed above, only very few studies report their results using Kaplan-Meier analysis.

Our opinion is that when the results obtained with TCT are compared with those obtained after transsternal thymectomy the complete remission rates are very similar. Table 1 shows selected results of some of the larger studies of thymectomy published within the last 25 years that used reasonable data reporting and analysis. This table gives a sense of the complete response rate ranges reported within the literature [10, 14, 15, 18–31]. In summary of this data it can be stated that crude CR rates range from 19 to 58% after sternotomy and 29 to 44% after TCT. Clearly these ranges are overlapping. Kaplan-Meier CR rates which, however, have been rarely reported (as far as we know they are reported exclusively in the qualifying publications that show a value in the last column in Table 1) also appear similar. It is worth noting that Kaplan-Meier estimates for CR at extended time points (not shown in table) are even higher (91% at 10 years) after one version of TCT [14] than after "maximal" thymectomy [10] (81% at 7.5 years).


View this table:
[in this window]
[in a new window]

  		Table 1 Published Results of Five Approaches to Thymectomy a
 
We recognize that patients in the TCT studies generally have had a lower preoperative severity of disease, and that they also have tended to be operated upon somewhat earlier in the course of their disease; but this is in fact one of the advantages of TCT and perhaps other minimally invasive approaches, that patients and neurologists are likely to accept it more readily and thus bring people to thymectomy earlier. To discount results that may have been obtained in part because of this advantage would be, we believe, inappropriate.

Comparing CSR rates after TCT to those after VATS and robotic approaches can be difficult because there are so few VATS and robotic studies with both a reasonable number of patients enrolled (we chose at least n = 48 to list a study in Table 1) and full reporting of the important parameters at this early stage in the development of the techniques. Additionally, the VATS approach has been described with so many different technical variations (eg, right versus left versus bilateral approaches, addition of a cervical incision, addition of a sternum-lifting retractor) that it is hard to know which variation one should be evaluating. Overall, we believe that the literature shows an advantage of TCT over VATS in response rates, and there is only one carefully evaluated robotic series with which to compare. Other than the single study by Tomulescu and colleagues [29] listed in Table 1, crude CSR rates after VATS thymectomy cover a range from 14 to 40% (versus 29 to 44% for TCT), and Kaplan-Meier CSR rates after VATS thymectomy have either not been reported, or are so high (in small studies) as to be impossible to believe given all other published data. The largest report of robotic thymectomy [31] describes 106 patients and represents nearly one-quarter of the world's published experience. The 5-year Kaplan-Meier CSR rate in this study was approximately 40% (drawn from a figure in the publication), which does suggest that its results are at least equal those of TCT. The need for the robot, however, creates costs and other hurdles that currently prevent wide dissemination of this technique.

Only with a randomized, prospective study comparing TCT to sternotomy (and possibly VATS-robotic approaches) or at a minimum a carefully designed prospective registry, will these controversies be resolved. The latter is far more likely to be successful given the lack of equipoise that many surgeons have on this issue and thus the unlikelihood of accruing well to a randomized study. Neither study would be appropriate, however, until the primary question is resolved; ie, whether any form of thymectomy is more effective than medical therapy in MG or some subset of MG patients. This question should be answered by the ongoing multicenter trial that has been organized by the MGFA. If the results of that study show a benefit of thymectomy over prednisone, the next important step would be to organize a means of effectively evaluating TCT versus thymectomy through sternotomy (and possibly VATS-robotics). Such a study would find wide support within the surgical community.

As Jaretzki and colleagues have written [32], the optimal surgical technique for thymectomy in MG will be the one that "... balances extent of resection, morbidity, patient acceptance, and results." In the current environment, where when carries out a thymectomy for MG one is performing a potentially morbid operation that has no level I data to support it, minimizing morbidity and mortality becomes paramount. As it is clear that TCT is less morbid and costly than all other approaches to thymectomy, it is a very attractive option in this environment. We believe that CSR rates with TCT are as good or better than those after VATS approaches. We believe further that although the data are admittedly inconclusive, CSR rates with TCT are sufficiently similar to those after the extended transsternal and "maximal" thymectomy procedures to allow one to argue cogently that whatever small difference may exist in remission rates is likely outweighed by the larger difference in morbidity between the approaches.


   Acknowledgments
Top
 Abstract
 Introduction
 History
 Indications
 Operative Technique
 Results
 Controversy
 Acknowledgments
References
 
The author would like to thank Donna Minagawa for technical assistance in the creation of the manuscript.


   References
Top
 Abstract
 Introduction
 History
 Indications
 Operative Technique
 Results
 Controversy
 Acknowledgments
 References
 

  1. Jaretzki III A, Barohn RJ, Ernstoff RM, et al. Myasthenia gravis: recommendations for clinical research standards Ann Thorac Surg 2000;70:327-334.[Free Full Text]
  2. Wilks S. Guys Hospital Reports 1877;22:7-55.
  3. Jolly F. Über myasthenia gravis pseudoparalytica[in German] Berlin Klin Wschr 1895;32:1-7.
  4. Walker MB. Treatment of myasthenia gravis with physostigmine Lancet 1934;1:1200-1201.
  5. Osserman KE, Genkins G. Studies in myasthenia gravis: review of a twenty year experience in over 1200 patients Mt Sinai J Med 1971;38:497-537.[Medline]
  6. Blalock A. Thymectomy in the treatment of myasthenia gravis: report of twenty cases J Thorac Surg 1944;13:316-319.
  7. Kirshner PA, Osserman KE, Kark AK. Studies in myasthenia gravis: transcervical total thymectomy JAMA 1969;209:906-910.[Medline]
  8. Papatestas AE, Genkins G, Kornfeld P, et al. Effects of thymectomy in myasthenia gravis Ann Surg 1987;206:79-88.[Medline]
  9. Jaretzki III A, Bethea M, Wolff M, et al. A rational approach to total thymectomy in the treatment of myasthenia gravis Ann Thorac Surg 1977;24:120-130.[Abstract/Free Full Text]
  10. Jaretzki 3rd A, Wolff M. "Maximal" thymectomy for myasthenia gravis. Surgical anatomy and operative technique. J Thorac Cardiovasc Surg 1988;96:711-716.[Abstract]
  11. Cooper JD, Al-Jilaihawa AN, Pearson FG, Humphrey JG, Humphrey HE. An improved technique to facilitate transcervical thymectomy for myasthenia gravis Ann Thorac Surg 1988;45:242-247.[Abstract/Free Full Text]
  12. Gronseth GS, Barohn RJ. Practice parameter: thymectomy for autoimmune myasthenia gravis (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology Neurology 2000;55:7-15.[Free Full Text]
  13. Deeb ME, Brinster CJ, Kucharzuk J, Shrager JB, Kaiser LR. Expanded indications for transcervical thymectomy in the management of anterior mediastinal masses Ann Thorac Surg 2001;72:208-211.[Abstract/Free Full Text]
  14. dePerrot M, Bril V, McRae K, Keshavjee S. Impact of minimally invasive transcervical thymectomy on outcome in patients with myasthenia gravis Eur J Cardiothorac Surg 2003;24:677-683.[Abstract/Free Full Text]
  15. Shrager JB, Nathan D, Brinster CJ, et al. Outcomes after 151 extended transcervical thymectomies for myasthenia gravis Ann Thorac Surg 2006;82:1863-1869.[Abstract/Free Full Text]
  16. Shrager JB, Deeb ME, Mick R, et al. Transcervical thymectomy for myasthenia gravis achieves results comparable to thymectomy by sternotomy Ann Thorac Surg 2002;74:320-326.[Abstract/Free Full Text]
  17. Miano MA, Bosley TM, Heiman-Patterson TD, et al. Factors influencing outcome of prednisone dose reduction in myasthenia gravis Neurology 1991;41:919-921.[Abstract/Free Full Text]
  18. Ashour MH, Jain SK, Kattan KM, et al. Maximal thymectomy for myasthenia gravis Eur J Cardiothorac Surg 1995;9:461-464.[Abstract/Free Full Text]
  19. Budde JM, Morris CD, Gal AA, Mansour KA, Miller Jr JI. Predictors of outcome in thymectomy for myasthenia gravis Ann Thorac Surg 2001;72:197-202.[Abstract/Free Full Text]
  20. Busch C, Machens A, Pichlmeier U, Emskötter T, Izbicki JR. Long-term outcome and quality of life after thymectomy for myasthenia gravis Ann Surg 1996;224:225-232.[Medline]
  21. Klein M, Heidenreich F, Madjlessi F, et al. Early and late results after thymectomy in myasthenia gravis : a retrospective analysis Thorac Cardiovasc Surg 1999;47:170-173.[Medline]
  22. Masaoka A, Yamakawa Y, Niwa H, et al. Extended thymectomy for myasthenia gravis patients: a 20 year review Ann Thorac Surg 1996;62:853-859.[Abstract/Free Full Text]
  23. Mulder DG, Graves M, Hermann C. Thymectomy for myasthenia gravis: recent observations and comparisons with past experience Ann Thorac Surg 1989;48:551-555.[Abstract/Free Full Text]
  24. Stern LE, Nussbaum MS, Quinlan JG, Fischer JE. Long-term evaluation of extended thymectomy with anterior mediastinal dissection for myasthenia gravis Surgery 2001;130:774-778.[Medline]
  25. Huang CS, Hsu HS, Huang BS, et al. Factors influencing the outcome of transsternal thymectomy for myasthenia gravis Acta Neurol Scand 2005;112:108-114.[Medline]
  26. Durelli L, Maggi GM, Casadio C, Ferri R, Rendine S, Bergamini L. Actuarial analysis of the occurrence of remissions following thymectomy for myasthenia gravis in 400 patients J Neurol Nerosurg Psychiatry 1991;54:406-411.[Abstract/Free Full Text]
  27. Bril V, Kojic J, Ilse WK, Cooper JD. Long-term clinical outcome after transcervical thymectomy for myasthenia gravis Ann Thorac Surg 1998;65:1520-1522.[Abstract/Free Full Text]
  28. Calhoun RF, Ritter JH, Guthrie TJ, et al. Results of transcervical thymectomy for myasthenia gravis in 100 consecutive patients Ann Surg 1999;230:555-559.[Medline]
  29. Tomulescu V, Ion V, Kosa A, Sgarbura O, Popescu I. Thoracoscopic thymectomy mid-term results Ann Thorac Surg 2006;82:1003-1007.[Abstract/Free Full Text]
  30. Lin TS, Tzao C, Lee SC, et al. Comparison between video-assisted thoracoscopic thymectomy and transternal thymectomy for myasthenia gravis (analysis of 82 cases) Int Surg 2005;90:36-41.[Medline]
  31. Rückert JC, Ismail M, Swierzy M, et al. Thoracoscopic thymectomy with the da Vinci robotic system for myasthenia gravis Ann N Y Acad Sci 2008;1132:329-335.[Medline]
  32. Jaretski A, Steinglass KM, Sonnett JR. Thymectomy in the management of myasthenia gravis Sem Neurol 2004;24:49-62.[Medline]



This article has been cited by other articles:


Home page
 J. Thorac. Cardiovasc. Surg.Home page
G. Marulli, M. Schiavon, E. Perissinotto, A. Bugana, F. Di Chiara, A. Rebusso, and F. Rea
Surgical and neurologic outcomes after robotic thymectomy in 100 consecutive patients with myasthenia gravis
J. Thorac. Cardiovasc. Surg., March 1, 2013; 145(3): 730 - 736.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
R. K. Freeman, A. J. Ascioti, J. M. Van Woerkom, A. Vyverberg, and R. J. Robison
Long-Term Follow-Up After Robotic Thymectomy for Nonthymomatous Myasthenia Gravis
Ann. Thorac. Surg., September 1, 2011; 92(3): 1018 - 1023.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Joseph B. Shrager
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shrager, J. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shrager, J. B.
Related Collections
Right arrow Minimally invasive surgery

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS