Bilateral video-assisted thoracoscopic thymectomy has a surgical extent similar to that of transsternal extended thymectomy with more favorable early surgical outcomes for myasthenia gravis patients

Trends and Disparities in the Utilization of Thymectomy for Myasthenia Gravis in the United States

Background and Objectives

In 2016, a randomized controlled trial demonstrated the clinical efficacy of trans-sternal thymectomy for patients with non-thymomatous myasthenia gravis (MG). Whether large-scale changes occurred in clinical practice after this trial is unknown.

Methods

We performed a retrospective longitudinal cross-sectional analysis using National Inpatient Sample (NIS) data from 2012 to 2019. Our study included hospitalized adults at least 18 years of age diagnosed with MG without an associated thymoma. We used joinpoint regression to analyze annual trends in thymectomy volume and surgical approach (minimally invasive vs trans-sternal) from 2012 to 2019. Using logistic regression models, we examined patient and hospital-level factors that may have influenced whether thymectomy was performed, such as age, sex, race, insurance payor, hospital size and teaching status, and Elixhauser Comorbidity Index. Sampling weights were applied to account for the complex survey design of NIS.

Results

The total number of thymectomy procedures increased by 69.8% per year (95% CI 40.1-105.8) between 2012 and 2019. Trans-sternal thymectomies increased by 62.8% per year (95% CI 35.8-95.2) and minimally invasive thymectomies by 83.7% per year (95% CI 38.1-144.3). Thymectomies were significantly more likely to occur in 2017-2019 compared with 2012-2016 (OR 1.93, 95% CI 1.62-2.31). In a multivariable regression model, several factors decreased the odds of patients with MG having a thymectomy: older age, Black race (OR 0.62, 95% CI 0.49-0.77), female (OR 0.73, 95% CI 0.63-0.86), and higher Elixhauser Comorbidity Index. Patients in medium (OR 1.82, 95% CI 1.30-2.55) or large (OR 2.81, 95% CI 2.07-3.82) size and urban teaching hospitals (OR 6.09, 95% CI 2.65-13.97) were more likely to undergo thymectomy.

Discussion

Thymectomy is being performed more frequently for non-thymomatous MG, especially after 2016 after publication of a positive phase III clinical trial. There are several disparities in thymectomy utilization that warrant further attention.

Application of near-infrared fluorescence imaging with indocyanine green in mediastinal surgery

Intraoperative near-infrared (NIR) fluorescence imaging has emerged in recent years and is now used in many surgical procedures. Intraoperative fluorescence imaging can guide surgeons in identifying and localizing specific structures and boundaries, which can facilitate the optimization of surgical procedures. The components of the mediastinum are complex and functionally important, making identifying and locating different structures intraoperatively challenging, and NIR fluorescence imaging has potential clinical value in mediastinal surgery. Here we review the applications of NIR fluorescence imaging technology in mediastinal surgery in recent years.

Spontaneous Ventilation Combined with Double-Lumen Tube Intubation during Thoracic Surgery: A New Anesthesiologic Method Based on 141 Cases over Three Years

BACKGROUND

Non-intubated thoracic surgery has not achieved widespread acceptance despite its potential to improve postoperative outcomes. To ensure airway safety, our institute has developed a technique combining spontaneous ventilation with double-lumen tube intubation (SVI). This study aimed to verify the feasibility and limitations of this SVI technique.

METHODS

For the SVI method, anesthesia induction involves fentanyl and propofol target-controlled infusion, with mivacurium administration. Bispectral index monitoring was used to ensure the optimal depth of anesthesia. Short-term muscle relaxation facilitated double-lumen tube intubation and early surgical steps. Chest opening preceded local infiltration, followed by a vagal nerve blockade to prevent the cough reflex and a paravertebral blockade for pain relief. Subsequently, the muscle relaxant was ceased. The patient underwent spontaneous breathing without coughing during surgical manipulation.

RESULTS

Between 10 March 2020 and 28 October 2022, 141 SVI surgeries were performed. Spontaneous respiration with positive end-expiratory pressure was sufficient in 65.96% (93/141) of cases, whereas 31.21% (44/141) required pressure support ventilation. Only 2.84% (4/141) of cases reversed to conventional anesthetic management, owing to technical or surgical difficulties. Results of the 141 cases: The mean maximal carbon dioxide pressure was 59.01 (34.4-92.9) mmHg, and the mean lowest oxygen saturation was 93.96% (81-100%). The mean one-lung, mechanical and spontaneous one-lung ventilation time was 74.88 (20-140), 17.55 (0-115) and 57.73 (0-130) min, respectively.

CONCLUSIONS

Spontaneous ventilation with double-lumen tube intubation is safe and feasible for thoracic surgery. The mechanical one-lung ventilation time was reduced by 76.5%, and the rate of anesthetic conversion to relaxation was low (2.8%).

Safety and feasibility of a modularized procedure for trans-subxiphoid robotic extended thymectomy

BACKGROUND

The purpose of this study was to introduce an "eight-step modularized procedure (M-RET)" for trans-subxiphoid robotic extended thymectomy for patients with myasthenia gravis (MG). Its safety and feasibility were further verified in this study.

MATERIALS AND METHODS

This retrospective study included 87 consecutive MG patients who underwent trans-subxiphoid robotic extended thymectomy at our institution between September 2016 and August 2021. According to different resection models, patients were divided into two groups: traditional trans-subxiphoid robotic extended thymectomy group (T-RET group) and eight-step modularized technique group (M-RET group). Baseline demographic characteristics and operation-related parameters were collected and compared between the two groups.

RESULTS

There were 41 (47.1%) patients in the M-RET group and 46 (52.9%) patients in the T-RET group. The M-RET group resected a greater amount of mediastinal adipose tissues and required more dissection time (median and interquartile range: 135.0, 125.0 to 164.0 v. 120.0, 105.0 to 153.8, P = 0.006) compared with the T-RET group. There were no statistically significant differences in terms of the intraoperative blood loss, duration of chest drainage, length of hospital stay, and postoperative complications between the two groups. There was no mortality or conversion in each of the two groups and all patients recovered well upon discharge.

CONCLUSION

The eight-step modularized technique of trans-subxiphoid robotic extended thymectomy was verified to be a safe, effective, radical procedure, which offers unique superiority over ectopic thymic tissue resection.

Subxiphoid and subcostal arch versus unilateral video-assisted thoracic surgery approaches to thymectomy for myasthenia gravis

PURPOSE

Thymectomy is an important treatment for myasthenia gravis (MG). We conducted this study to compare the clinical outcomes of the recently introduced subxiphoid and subcostal arch thymectomy (SASAT) approach with those of the standard unilateral video-assisted thoracoscopic surgery (VATS).

METHODS

We analyzed, retrospectively, the perioperative, and long-term outcomes of 179 consecutive MG patients (age 18-65 years), who underwent SASAT or unilateral VATS-extended thymectomy between July, 2012 and May, 2019.

RESULTS

All demographic and clinical characteristics were comparable in the two groups. The median surgical time, estimated blood loss, thoracotomy conversion rate, total and chest drainage, and complications did not differ significantly between the groups. The visual analog scale (VAS) score was significantly lower in the SASAT group. Complete stable remission (CSR) was achieved in a significantly larger proportion of the SASAT group patients and was significantly higher in women than in men. The Quantitative MG score was significantly lower in the SASAT group. Patients in the MG Foundation of America Clinical Classification groups I and II achieved better remission rates than those in groups III-V.

CONCLUSIONS

SASAT is a safe and feasible MG treatment, which may yield better outcomes than unilateral VATS and improve the quality of treatment.

Transareolar uniportal thoracoscopic extended thymectomy for patients with myasthenia gravis

Background

Transareolar uniportal thoracoscopic extended thymectomy (TUTET) has not been previously reported. We attempted to assess the feasibility and safety of TUTET for male myasthenia gravis (MG) patients.

Patients and methods

From February 2013 to February 2020, 46 men with MG underwent TUTET. All patients were followed up for 12–84 months postoperatively by clinic visits or telephone/e-mail interviews.

Results

All surgeries were completed successfully, with an average operation time of 72.6 min. The mean length of transareolar uniportal incision was 3.0 ± 0.4 cm, and the mean postoperative cosmetic score was 3.1 ± 0.5 at discharge. Three months postoperatively, no patients had an apparent surgical scar on the chest wall or complained of postoperative pain. Substantial amelioration of the disease was achieved in a short period, and several benefits were clear. At the 1-year follow-up, all patients showed a good cosmetic effect and high satisfaction.

Conclusions

TUTET is an effective and safe way for men with MG. The uniportal incision is hidden in the areola with sound cosmetic effects. We believe that TUTET is an acceptable procedure for extended thymectomy.

Efficiency of ectopic thymectomy by three surgical approaches in non-thymomatous myasthenia gravis

Background

To explore the efficiency of ectopic thymectomy by the three surgical approaches of trans-sternum, right unilateral thoracoscopy and thoracoscopic subxiphoid in patients with non-thymomatous myasthenia gravis.

Methods

155 consecutive non-thymomatous myasthenia gravis patients who underwent extended thymectomy by 3 approaches including trans-sternum, right unilateral thoracoscopy and thoracoscopic subxiphoid in 1st affiliated hospital of Sun Yat-Sen University from January 2017 to October 2019 were reviewed. Differences of perioperative clinical characteristics in three surgical approaches were analyzed.

Results

Time to onset of myasthenia gravis (early or late) (p = 0.018), blood loss (p < 0.001), duration of operation (p = 0.031), duration and volume of thoracic drainage (p = 0.039 and p = 0.026), length of hospitalization (p = 0.039), the efficiency of ectopic thymectomy (p = 0.037), and the detection rate of ectopic thymus in the second quadrant (p = 0.018) were different among the three surgical approaches. In univariate logistic regression analysis, higher efficiency of ectopic thymectomy were associated with transsternal (OR 2.36, 95% CI 1.32–4.22, p = 0.011) and thoracoscopic subxiphoid approaches (OR 2.07, 95% CI 1.12–3.82, p = 0.033). In the multiple logistic regression analysis, the transsternal approach (OR 2.02, 95% CI 1.10–3.71, p = 0.024) was an independent protective factor for the efficiency of ectopic thymectomy.

Conclusions

Both the right unilateral thoracoscopic and thoracoscopic subxiphoid approaches have advantages over the transsternal approach in short-term postoperative recovery. Transsternal approach is still the best choice for ectopic thymectomy while thoracoscopic subxiphoid approach show the potential as an alternative way.

Comparison of two-lung and one-lung ventilation in bilateral video-assisted thoracoscopic extended thymectomy in myasthenia gravis: a retrospective study

Background

Myasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.

Methods

We retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0–T8) and collected respiratory and hemodynamic variables, including arterial O₂ index (PaO₂/FiO₂).

Results

SpO₂ at T1–T3 and T8 was significantly lower in group D than in group S. The FiO₂ in group S was lower than that in group D at all time points. The number of PaO₂/FiO₂ ≤ 300 and PaO₂/FiO₂ ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D.

Conclusions

This retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.

Role of thymus on prognosis of myasthenia gravis in Turkish population

OBJECTIVE:

Myasthenia gravis (MG) is an autoimmune disease that may cause a disorder in transmission at the neuromuscular junction. Antibodies directed against acetylcholine receptors are responsible. The thymus is the place that that production of these antibodies mainly occurs. The thymus gland abnormalities and abnormal production of these antibodies are associated with MG. Consequently, thymectomy is a common treatment for MG. The nature of the disease makes it difficult to plan prospective, controlled trials; therefore, there is no current consensus among clinicians on a single algorithm of treatment, and the approach is frequently based on the observations and experiences of experts. The contributions to the literature largely consist of retrospective studies examining an approach to treatment and the effects of thymectomy on prognosis. In this retrospective study, evaluation of Turkish patients with myasthenia gravis was carried out for the importance of thymectomy and effects on prognosis.

METHODS:

In this study, 93 patients with myasthenia gravis whose followed up at Neuromuscular outpatient clinic between 1998–2018 were evaluated retrospectively. Type of disease, antibody status, treatment, thymectomy, thymus pathology and prognosis were assessed.

RESULTS:

Thymectomy had been a positive effect on the prognosis of the disease independent of the duration of disease and thymic pathology. The best results had been obtained with early thymectomy with short disease duration, younger age and patients with thymic hyperplasia. Success of therapy was limited with thymoma. With advanced age need for thymectomy was decreased.

CONCLUSION:

In the present study, evaluation of 93 patients with myasthenia gravis was done retrospectively and it was concluded that thymectomy had a positive effect on prognosis, especially in young patients when performed as early as possible. The most successful results were obtained in cases with thymic hyperplasia.

Robotic assisted minimally invasive thymectomy with simultaneous bilateral thoracoscopy and contralateral phrenic nerve visualization

Background

Thoracoscopic approaches to thymectomy and anterior mediastinal mass resection has become increasingly common due to the potential for decreased blood loss and hospital length of stay. However, contralateral mediastinal and phrenic nerve visualization if often difficult from these unilateral approaches, which may affect the ability to achieve a full phrenic to phrenic dissection Herein, we present our early experience of robotic assisted minimally invasive thymectomy (RAMIT) with simultaneous bilateral thoracoscopy and contralateral phrenic nerve visualization.

Methods

This was a retrospective review of all sequential patients undergoing RAMIT with simultaneous bilateral thoracoscopy from January 2015 to May 2016. This study was approved by our Institutional Review Board (PRO15080367). Individual patient consent was waived.

Results

Twenty-six patients [median age 58 (range, 29-76) years] were included in this study. Sixteen operations were performed for anterior mediastinal mass, 7 for non-thymomatous myasthenia gravis, and 3 for concurrent myasthenia gravis and thymoma. Median blood loss and hospital stay were 25 mL (range, 3-150 mL) and 3 days (range, 2-8 days), respectively. Twenty-one (80.8%) patients experienced an uncomplicated hospital course. The highest graded complication by Clavien Dindo Classification was a grade III due to pleural effusion requiring drainage via pleural catheter. One patient experienced asymptomatic hemidiaphram palsy postoperatively. There were no 90-day postoperative deaths.

Conclusions

RAMIT with simultaneous bilateral thoracoscopy is a feasible approach that may allow for enhanced visualization and more complete thymic resection compared to existing unilateral minimally invasive operations. Comparative studies and long-term follow up are needed to adequately assess the potential benefits of RAMIT.

Risk factors of myasthenia crisis after thymectomy among myasthenia gravis patients: A meta-analysis

BACKGROUND

The purpose of the study was to determine the risk factors of post-surgery myasthenia crisis (PMC) among myasthenia gravis (MG) patients.

METHODS

A meta-analysis to synthesize all eligible literatures was conducted to analyze PMC predictors among MG patients.

RESULTS

A total of 15 trials with 2626 patients were included for the meta-analysis. As a result, patients with history of MC (RR = 3.36, 95%CI: 2.46-4.59, P < .001), generalized MG (RR = 0.39, 95%CI: 0.26-0.59, P < .001), bulbar symptom (RR = 3.59,95%CI:2.53-5.09, P < .001), thymoma (RR = 2.10, 95%CI:1.37-3.21, P = .001), post-surgery morbidity presence(RR = 2.59, 95%CI:1.90-3.54, P < .001), high-dose pyridostigmine usage (SMD = 0.480, 95%CI: 0.35-0.61 P < .001) tended to develop PMC. Large dose of steroid may reduce the incidence of PMC (RR = 0.41 95%CI: 0.18-0.94, P = .036). Regular steroid use (P = .066), immunosuppressive therapy (P = .179), gender (P = .774), and age at thymectomy (P = .212) had no impact upon PMC development.

CONCLUSION

History of PMC, thymoma, generalized MG, bulbar symptom, and concomitant complication are the risk factors of PMC.

Comparison between thoracoscopic and open approaches in thymoma resection

Background

To investigate the feasibility and indications of video-assisted thoracic surgery (VATS) in thymoma resection.

Methods

The clinical data of 103 patients undergoing thymoma resection via different approaches [including conventional lateral thoracotomy approach (LTA) in 41 cases, median sternotomy approach (MSA) in 40 cases, and right-sided VATS in 22 cases] were analyzed. Among them, 59, 13, 25, and 6 patients were in Masaoka stage I, II, III, and IV, respectively. Myasthenia gravis (MG) was also found in 54 cases. The patients were followed up for postoperative survival and the improvement in MG. The prognostic indicators of patients undergoing thymoma resection via different surgical approaches (i.e., LTA, MSA, and VATS) were statistically analyzed.

Results

Eight of 103 patients died. Six patients underwent unilateral sacral nerve resection, among whom 4 patients developed respiratory dysfunction, and 3 died. Two patients died of MG after surgery, 1 patient died of tumor recurrence and metastasis, 1 patient died of heart disease, and the cause of death was unknown in the remaining patient. The drainage time was shorter in VATS group than in open groups, along with smaller tumor size. The VATS group also had shorter hospital stay in the whole series and the subgroup without accompanying MG. The improvement in MG showed no significant difference among the three surgical groups. Both 5- and 10-year survival rates were 91% in the entire cohort.

Conclusions

VATS is like a conventional surgeries for improving MG in thymoma patients with accompanying MG. VATS resection can still be considered for thymoma that only invades the mediastinal pleura. For thymomas that have intact capsules and have not invaded mediastinal pleura, MSA surgery shall be performed to ensure patient safety if the anteroposterior diameters of the tumors are large and the masses have produced severe compression of the innominate vein, even if the tumors are still in the Masaoka stage II. For thymomas with large left-to-right diameters and with most parts of the tumors located in the left thoracic cavity, a left-sided approach (either VATS or an open approach) may be used in the absence of MG; if MG accompanies the condition, an MT approach or a bilateral VATS may be considered. In patients with unilateral pericardial phrenic nerve and/or local pericardial involvement, right-sided VATS thymectomy may be considered for thymomas located at the right side and bilateral VATS surgery can be performed for tumors located at the left side. In summary, VATS is feasible for the treatment of thymoma complicated by MG. VATS can be performed in patients with Masaoka stage I, II and (a certain portion of) III thymoma; for some patients with Masaoka stage II thymoma, especially those with compression of the innominate vein, the use of VATS should be cautious.

Pediatric thymectomy: a study of national trends in demographics, short-term outcomes, and cost

BACKGROUND

Thymectomy in pediatric patients is an effective treatment for myasthenia gravis (MG), thymic neoplasms, and other rarer pathologies. It is an uncommon procedure in children and studies have focused on small, single-institution cohorts. We sought to better characterize its use by utilizing a national database.

METHODS

The Kids' Inpatient Database was used to identify hospital discharge records of patients ≤ 20 years old who underwent thymectomy. A retrospective cross-sectional analysis for 2003, 2006, 2009, and 2012 was performed. Trends in patient characteristics, diagnosis, surgical approach, and short-term outcomes were analyzed. Risk factors were identified using univariate and multivariate analyses.

RESULTS

There were 600 thymectomies identified. MG was the most common indication. Thoracoscopy is being used increasingly for all diagnoses except malignancy. The overall morbidity rate was 14.0%, with respiratory complications representing the largest group. No in-hospital deaths were identified. Private insurance was associated with shorter hospital stays and lower costs. Hispanic race was associated with more complications, longer stays, and higher costs. Thoracoscopic thymectomies had shorter stays than open procedures.

CONCLUSION

Thymectomy in the pediatric population is being performed safely, with low morbidity and no identified mortalities. Thoracoscopy results in reduced length of stay and is being used increasingly. Of note, socioeconomic and racial factors impact outcomes.

Surgical Techniques for Myasthenia Gravis: Video-Assisted Thoracic Surgery

We describe the various video-assisted thoracic surgery approaches to the thymus currently adopted in nonthymomatous and thymomatous myasthenic patients. Despite several controversies, video-assisted thoracic surgery thymectomy gained worldwide popularity. Classic 3-port approaches proved safe and effective. Uniportal video-assisted thoracic surgery requires consolidated experience, whereas the bilateral approach is considered more extensive. Subxiphoid represents the ultimate and exciting challenge. As an effect of video-assisted thoracic surgery approach, thymectomy is performed earlier; both patients and neurologists are more prone to accept the procedure given the quicker recovery, lesser pain, and better cosmesis. Outcomes are equivalent to those achieved by sternotomy.

A Neurologist's Perspective on Thymectomy for Myasthenia Gravis: Current Perspective and Future Trials

The first randomized blinded study of thymectomy in nonthymomatous myasthenia gravis was designed to answer 3 questions: does the combination of prednisone and removal of the thymus gland via extended transsternal thymectomy after 3 years compared with an identical dosing protocol of prednisone alone (1) lead to better disease status for generalized MG patients with antiacetylcholine receptor antibodies, (2) reduce their prednisone requirements, and/or (3) reduce the side-effect burden from medications used to treat the disease? The study demonstrated that thymectomy confers these benefits for patients and sets the stage for inquiries into the benefits of less-invasive approaches to thymic resection.

Predictive value of the thymofatty specimen weight index in outcomes of extended thymectomy due to non-thymomatous myasthenia gravis

OBJECTIVES

To evaluate the predictive value of the intraoperative thymofatty specimen weight (TFSW) index on predicting the prognosis of extended thymectomy (ET) for non-thymomatous myasthenia gravis.

METHODS

This is a prospective non-interventional study in which patients who underwent ET between January 2012 and June 2015 were enrolled. Resected thymus and surrounding adipose tissues were weighed using an electronic scale intraoperatively and adjusted to the body surface area (BSA) to calculate the TFSW index. The primary end point was defined as complete stable remission (CSR) according to the Myasthenia Gravis Foundation of America (MGFA) guidelines.

RESULTS

One hundred and eighteen patients who completed postoperative follow-up were included in this study. After a mean follow-up period of 44 months, 68 (57.6%) patients reached clinical CSR. The MGFA class, histopathology and TFSW index were associated with a postoperative CSR in univariate analysis. When the Cox hazard multiple regression model was used, the TFSW index was found to be an independent predictor for CSR (hazard ratio 2.056; 95% confidence interval 1.182-3.576). Based on ROC analysis, an optimal TFSW index cut-off value (35.9 g/m2) with the highest sensitivity and specificity was determined.

CONCLUSIONS

The TFSW index is an important independent predictor for mid-term CSR after ET in non-thymomatous myasthenia gravis patients. During the ET surgery, every effort should be made to take a tissue specimen with a TFSW index more than 35.9 g/m2.

Subxiphoid and subcostal arch "Three ports" thoracoscopic extended thymectomy for myasthenia gravis

Background

The approaches to thoracoscopic thymectomy in myasthenia gravis (MG) are debatable. We developed a novel approach via subxiphoid and subcostal arch, with a significantly shorter duration of operation and hospital stay, less estimated blood loss, and lower postoperative pain.

Methods

From December 2012 to December 2014, 77 myasthenia gravis patients with or without thymoma underwent thoracoscopic extended thymectomy at our hospital. Among them, 41 patients were operated via the subxiphoid and subcostal arch approach and the other 36 via the conventional unilateral approach. The patient outcomes were retrospectively reviewed and evaluated.

Results

The thoracoscopic extended thymectomy was performed safely via the subxiphoid and subcostal arch approach. In this approach, no drainage tube was inserted after operation except in the first two patients. Two of the 41 patients were switched to trans-sternal approach due to the tight adhesion between the thymoma and the left innominate vein. No major complications occurred. Compared with the unilateral approach, the duration of the procedure via subxiphoid and subcostal arch was significantly shorter, with less estimated blood loss, shorter hospital-stay and lower postoperative pain (P<0.001). The cosmetic scores were comparable between the two groups (P=0.369).

Conclusions

The novel subxiphoid and subcostal arch approach is technically feasible and safe. It is an acceptable alternative to conventional thoracoscopic extended thymectomy.

Thoracoscopic Thymectomy Using a Subxiphoid Approach for Anterior Mediastinal Tumors

PURPOSE

Video-assisted thoracic surgery (VATS) techniques have been widely used for resection of mediastinal tumors. This study investigated the usefulness of the subxiphoid approach in thoracoscopic thymectomy.

METHODS

In all, 36 patients with anterior mediastinal tumor underwent thymectomy using the subxiphoid approach in two Japanese institutions. These patients were retrospectively reviewed and analyzed.

RESULTS

There were 16 females and 20 males with a mean age of 57 years. Five patients underwent partial thymectomy (PT), 27 underwent total or subtotal thymectomy, and 4 underwent thymectomy with combined resection (CR) of the surrounding organs or tissues. The mean maximum tumor diameter, amount of resected tissue, and blood loss were 4.1 cm, 72.5 g, and 20.6 g, respectively. More than half of tumors were diagnosed as thymoma (n = 19). The operation time was prolonged with a greater volume of thymectomy. The duration of chest tube drainage and postoperative stay were 1.7 ± 1.0 days and 5.9 ± 7.6 days, respectively. Four patients suffered intraoperative and postoperative complications, as follows: bleeding of the innominate vein, bleeding of the internal thoracic vein, crisis of myasthenia gravis (MG), pericarditis, and phrenic nerve paralysis. There were no mortalities after surgery.

CONCLUSION

Subxiphoid thoracoscopic thymectomy might be a safe and useful approach for mediastinal tumors.

Minimally invasive surgical procedures for thymic disease in Asia

Video-assisted thoracic surgery (VATS) procedures for thymic tumors and myasthenia gravis were introduced in Asia in the middle 1990s in at least two regions, Hong Kong and Japan. To overcome difficulties in obtaining a wide view of the anterior mediastinum, several methods for lifting the sternum or anterior chest wall have been presented, mainly by Japanese surgeons. More recently, single port VATS through a subxiphoid incision was also introduced in Japan. The long-term outcome of a VATS extended thymectomy for myasthenia gravis has been shown to be comparable to that of a trans-sternal extended thymectomy, while the long-term outcome of a VATS thymectomy for thymic epithelial tumors remains to be elucidated. Nevertheless, its indication for tumors in an early stage is now widely accepted, and the number of VATS procedures is steadily increasing in Japan and China. Single-port VATS through a subxiphoid incision was developed in Japan and might become accepted as a useful approach in the near future when combined with robot-assisted thoracoscopic surgery. In addition, robot-assisted thoracoscopic surgery for the thymus has also been introduced in some areas in Asia. Although few of those surgical procedures for the thymus have been performed, results obtained thus far indicate that it might be preferable to lung resection. Several novel minimally invasive thymectomy techniques have been invented and developed in Asia, and further advancements in this field by Asian surgeons are anticipated.

Sternotomy versus video-assisted thoracoscopic surgery for thymectomy of myasthenia gravis patients: A meta-analysis

INTRODUCTION

The purpose of this study was to compare thymectomy by video-assisted thoracoscopic surgery (VATS) and trans-sternal thymectomy (TS) for myasthenia gravis patients.

METHODS

A meta-analysis was conducted to compare thoracoscopic surgery and sternotomy for myasthenia gravis patients with regard to long-term effect and short-term safety.

RESULTS

A total of 23 trials were included in our research. No significant differences were detected with regard to myasthenic crisis, wound infection, and muscle weakness improvement. VATS led to less blood loss than TS (standardized mean difference, -1.233; 95% confidence interval, -1.425--1.041; P < 0.001), less risk of pulmonary infection (relative risk, 1.035; 95% confidence interval, 1.001-1.070; P = 0.043), and a shorter hospital stay. TS had a shorter operative time than VATS (standardized mean difference, 0.239; 95% confidence interval, 0.113-0.365; P < 0.001). VATS and TS achieved similar mean specimen weights and complete stable remission rates.

CONCLUSION

Based on the results of this meta-analysis of retrospective cohort studies, VATS increases surgical safety and achieves an equal surgical efficacy to TS, but TS has a shorter operative time.

Randomized Trial of Thymectomy in Myasthenia Gravis

BACKGROUND

Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone.

METHODS

We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period.

RESULTS

A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003).

CONCLUSIONS

Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

Outcomes of thoracoscopic thymectomy in patients with juvenile myasthenia gravis

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disorder of the postsynaptic neuromuscular junction resulting in fatigability of voluntary muscles. There has been increasing evidence supporting thymectomy for MG in adults, and evidence for the role of surgery in pediatric age groups is increasing. The purpose of this study is to describe the outcomes of our patients with juvenile MG undergoing thoracoscopic thymectomy.

MATERIAL AND METHODS

All patients with juvenile MG who underwent thoracoscopic thymectomy at Phoenix Children's Hospital between 1999 and 2014 were included. Patients were diagnosed by their treating neurologist. An Osserman and Genkins criterion was used to classify the severity of the disease and DeFilippi classification was used to assess remission.

RESULTS

Twelve patients underwent thoracoscopic thymectomy for juvenile MG during the time frame studied. Nine (75%) patients had an Osserman stage of IIB, with only two patients with ocular disease. There were no conversions to an open procedure. Seven (59%) patients had normal thymic histology, 4 (33%) had evidence of follicular hyperplasia and one (8%) had involutional changes. The median length of hospital stay was 2days (range 1-5days). There was no 30-day postoperative morbidity, reoperations or mortality. The median length of follow-up was 31months (range, 4-91months) and at the time of their last follow-up; all 12 (100%) patients had a DeFilippi Classification of 3 or better.

CONCLUSION

Surgery for MG in children is indicated for antibody-receptor-positive patients with moderate to severe disease. Thoracoscopic thymectomy is a safe and acceptable treatment for juvenile MG with good disease control. The low morbidity and shorter hospital duration make it an excellent option for consideration.

Bilateral thoracoscopic extended thymectomy versus sternotomy

Background

Complete open surgical resection is the standard treatment for thymoma and myasthenia gravis. We evaluated the feasibility of bilateral video-assisted thoracoscopic extended thymectomy, and compared it to surgery via sternotomy.

Methods

From 2011 to 2014, 43 patients undergoing thymectomy were divided into 2 groups: 23 underwent video-assisted thoracoscopic extended thymectomy, and 20 had thymectomy via sternotomy. The primary outcomes were postoperative pain score (visual analog scale) at 6, 12, 24, 48, and 72 h, and 1-month postoperatively, and morphine consumption in the first 48 h. Secondary outcomes were surgical and clinical results.

Results

There were no significant differences between the 2 groups in terms of demographics and preoperative clinical data. Compared to the sternotomy group, the video-assisted thoracoscopic thymectomy group had lower pain scores and morphine consumption at all time points, significantly less operative blood loss and chest drainage volume, and shorter hospital stay. The rates of improvement in myasthenia gravis were 85% and 86% in the video-assisted thoracoscopic thymectomy and sternotomy groups, respectively. No recurrence of thymoma was found in either group (median follow-up 27 months).

Conclusions

Our results seem to confirm that in selected cases, video-assisted thoracoscopic thymectomy allows complete resection of thymus and perithymic tissue, similar to sternotomy but with the known advantages of minimally invasive surgery including less pain and a good cosmetic result.

Thoracoscopic resection of bulky thymoma assisted with artificial pneumothorax: A report of 19 consecutive cases

The aim of the present study was to examine the feasibility and efficacy of thoracoscopic radical resection of large retrosternal thymoma using artificial pneumothorax. A retrospective analysis was performed on 19 patients with bulky thymoma who underwent thoracoscopic resection using artificial pneumothorax by CO₂ insufflation. The operations were performed with unilateral or bilateral thoracic incisions via single lumen endotracheal intubation and two-lung ventilation. This approach provided excellent exposure of the thoracic cavity and reliable control of the neuro-vascular structures in the anterior mediastinum, which was of vital importance for the extended resection of malignant thymoma. The operation time was 140.0±51.4 min without conversion to thoracotomy or sternotomy. The pathological diagnosis was confirmed by immunohistochemistry, including 5 cases of thymus lipomyoma, 1 case of thymus hyperplasia, 1 case of thymus cyst, 2 cases of type AB thymoma, 4 cases of type B1 thymoma, 4 cases of type B3 thymoma, and 2 cases of thymic carcinoma. Furthermore, there were no complications such as recurrent laryngeal nerve injury, phrenic nerve injury, pulmonary infection or atelectasis, with a hospital stay of 5.0±3.0 days. In conclusion, the thoracoscopic resection of thymoma using artificial pneumothorax is a preferable approach, that may be considered for patients with bulky retrosternal tumors.

Minimally invasive versus open thymectomy: a systematic review of surgical techniques, patient demographics, and perioperative outcomes

BACKGROUND

Thymectomy is the mainstay of treatment for thymoma and other anterior mediastinal tumors, and is often utilized in the management of patients with myasthenia gravis (MG). While traditionally approached through a median sternotomy, minimally invasive approaches to thymectomy have increasingly emerged. The present systematic review was conducted to compare perioperative and clinical outcomes following minimally invasive thymectomy (MIT) and open thymectomy (OT).

METHODS

Articles were obtained through a PubMed literature search. Comparative studies reporting clinical outcomes following MIT and OT were eligible for inclusion. We selected studies with full text availability, written in the English language, published after 2005 and with at least 15 patients in each arm. A descriptive analysis was performed.

RESULTS

Twenty studies were included, involving a total of 2,068 patients undergoing either MIT (n=838) or OT (n=1,230). Within individual studies, MIT and OT cohorts were well matched with regards to patient age and gender, but there was considerable variation across studies. Resected thymomas were consistently larger in OT groups, with mean diameter significantly larger in five studies (MIT, 29-52 mm; OT, 31-77 mm). MIT was consistently associated with a lower estimated blood loss (MIT, 20-200 mL; OT, 86-466 mL), chest tube duration (MIT, 1.3-4.1 days; OT, 2.4-5.3 days), and hospital length of stay (MIT, 1-10.6 days; OT, 4-14.6 days). There were no consistent differences in rates of perioperative complications, thymoma recurrence, MG complete stable remission, or 5-year survival.

CONCLUSIONS

In appropriately selected patients, MIT may reduce blood loss, chest tube duration, and hospital length of stay, with comparable clinical outcomes compared to OT via median sternotomy.

Minimally invasive mediastinal surgery

In the past, mediastinal surgery was associated with the necessity of a maximum exposure, which was accomplished through various approaches. In the early 1990s, many surgical fields, including thoracic surgery, observed the development of minimally invasive techniques. These included video-assisted thoracic surgery (VATS), which confers clear advantages over an open approach, such as less trauma, short hospital stay, increased cosmetic results and preservation of lung function. However, VATS is associated with several disadvantages. For this reason, it is not routinely performed for resection of mediastinal mass lesions, especially those located in the anterior mediastinum, a tiny and remote space that contains vital structures at risk of injury. Robotic systems can overcome the limits of VATS, offering three-dimensional (3D) vision and wristed instrumentations, and are being increasingly used. With regards to thymectomy for myasthenia gravis (MG), unilateral and bilateral VATS approaches have demonstrated good long-term neurologic results with low complication rates. Nevertheless, some authors still advocate the necessity of maximum exposure, especially when considering the distribution of normal and ectopic thymic tissue. In recent studies, the robotic approach has shown to provide similar neurological outcomes when compared to transsternal and VATS approaches, and is associated with a low morbidity. Importantly, through a unilateral robotic technique, it is possible to dissect and remove at least the same amount of mediastinal fat tissue. Preliminary results on early-stage thymomatous disease indicated that minimally invasive approaches are safe and feasible, with a low rate of pleural recurrence, underlining the necessity of a "no-touch" technique. However, especially for thymomatous disease characterized by an indolent nature, further studies with long follow-up period are necessary in order to assess oncologic and neurologic results through minimally invasive approaches. Furthermore, increased robotic experience and studies, including randomized controlled trials, are needed to validate the findings of the current literature.

Mediastinoscopic extended thymectomy for pediatric patients with myasthenia gravis

BACKGROUND

Extended thymectomy is indicated for children with myasthenia gravis (MG) when drug-resistance or dependence is seen. We have employed a technique for mediastinoscopic extended thymectomy (MET) on children with MG.

METHOD

A total of 14 children underwent MET at Kanagawa Children's Medical Center between 2005 and 2013. A mediastinal operation field was made by a V-shaped hook infrasternally to extirpate the thymus with adipose tissue around the thymus.

RESULTS

The operation time and the amount of blood loss were 182±44 minutes and 34±43 ml, respectively. Postoperative complications, in the form of transient paralysis of the right recurrent nerve, occurred in 2 patients. The median length of postoperative hospital stay was 4.5 days. After MET, 6 patients achieved complete remission and 7 patients achieved steroid dose reduction, but no improvement was seen in 1 patient.

CONCLUSIONS

This procedure offers the advantage of good surgical access for dissection around the bilateral phrenic nerves in extended total thymectomy, while achieving good cosmetic results.

Thymectomy for myasthenia gravis in children: a comparison of open and thoracoscopic approaches

PURPOSE

Thymectomy is an accepted component of treatment for myasthenia gravis (MG), but optimal timing and surgical approach have not been determined. Though small series have reported the feasibility of thoracoscopic resection, some studies have suggested that minimally invasive methods are suboptimal compared to open sternotomy owing to incomplete clearance of thymic tissue. Here we report the largest series of thymectomies for pediatric myasthenia gravis in the literature to date.

METHODS

A retrospective review of patients undergoing thymectomy for MG between 1990 and 2013 in a tertiary referral hospital was performed. Twelve patients who underwent thoracoscopic thymectomy were compared to 16 patients who underwent open thymectomy via median sternotomy. Postoperative outcomes were determined by electronic chart review in consultation with the treating pediatric neurologist. Disease severities were graded according to a modified Myasthenia Gravis Foundation of America (MGFA) Quantitative MG (QMG) score.

RESULTS

Overall, thoracoscopic resections tended to be performed on patients with earlier and less severe disease than open surgeries. Inpatient length of stay was significantly shorter after thoracoscopic surgery (mean 1.8 vs 8.0 days, p=0.045). The preoperative and postoperative MGFA QMG scores were equivalent between the two groups. Both groups experienced a decrease in disease severity (p<0.001) after median follow-up time of 23 months in the thoracoscopic group and 44 months in the open group.

CONCLUSIONS

Minimally invasive thymectomy for MG in children has increased in popularity as surgeons and neurologists compare the risks and benefits of surgery against other therapies. This analysis suggests that thoracoscopic thymectomy is not inferior to median sternotomy in terms of disease control in this small series, and that the morbidity of the thoracoscopic approach appears sufficiently low to be considered for early stage disease. Low perioperative morbidity and shortened hospital course make thoracoscopic thymectomy an attractive option in centers with sufficient medical and surgical experience.

Bilateral thoracoscopic thymectomy using a novel positioning system

Several techniques of bilateral video-assisted thoracoscopic extended thymectomy have been proposed, and each has its own proponents. We summarize our experience in 20 patients who underwent bilateral video-assisted thoracoscopic extended thymectomy, using a new patient positioning that amplifies the thoracoscopic view of the cardiophrenic regions which are often difficult to visualize with standard techniques. In all cases, en-bloc thymectomy with complete dissection of the mediastinal fatty tissue was achieved without sternal retractors or additional incisions.

Long-term results of thoracoscopic thymectomy for thymoma without myasthenia gravis

OBJECTIVE

To compare the feasibility and safety of thoracoscopic thymectomy with conventional sternotomy thymectomy for thymoma without myasthenia gravis.

METHODS

Data from 70 patients diagnosed with thymoma, who underwent thoracoscopic thymectomy (n = 25, Group T) or sternotomy thymectomy (n = 45, Group S) between March 2002 and March 2008, were retrospectively evaluated.

RESULTS

Mean follow-up durations were 78.0 ± 21.9 months and 70.0 ± 23.6 months in Groups T and S, respectively. No deaths occurred in Group T; seven deaths occurred in Group S, all > 1 month post follow-up. Durations of chest intubation and hospitalization were significantly shorter in Group T than in Group S. No significant between-group difference in the incidence of operative complications was observed. Tumour recurrence-free rates at 5 and 7 years postsurgery were 96% (both years) in Group T and 95% (both years) in Group S.

CONCLUSIONS

Long-term follow-up indicates that thoracoscopic thymectomy for thymoma without myasthenia gravis is effective and is well tolerated, and associated with low rates of operative complications and recurrence.

Video-assisted thymectomy with contralateral surveillance camera: a means to minimize the risk of contralateral phrenic nerve injury

OBJECTIVE

Thymectomy for thymoma has traditionally been performed through midsternotomy that provides excellent exposure for a complete and safe resection. Minimally invasive alternatives have not been extensively evaluated for this disease process because data regarding the long-term oncologic effectiveness of these techniques remain to be established. Furthermore, video-assisted surgery as a unilateral approach may compromise the extension of the resection and could cause irreversible damage to the phrenic nerve of the opposite side. We evaluated the clinical feasibility and safety of a bilateral concomitant video-assisted approach with contralateral surveillance camera in patients undergoing thymectomy for thymoma.

METHODS

Four patients (3 females, 1 male) with thymoma causing myasthenia gravis (MG) were operated thoracoscopically at our institute under general anesthesia with double-lumen endotracheal intubation. The patients were placed in a supine position, and a 5-mm 30-degree lens thoracoscope was introduced into the left pleural space. Two other 10-mm working channels were applied. En bloc thymectomy was then performed, including mediastinal and pericardial fat pads, other tissue, and pleura from the level of the thoracic inlet to the diaphragm. A second 5-mm thoracoscope was inserted into the right hemithorax, and it was kept inside during the entire procedure to allow lateral surveillance of the extension and safety of the resection. Carbon dioxide insufflation and valved ports were used.

RESULTS

The duration of the operation was 90 ± 72 minutes. Complete resection was achieved in all patients without any nerve injury. There were no perioperative adverse events. Gradual remission from extremity and ocular weakness was achieved after recovery.

CONCLUSIONS

The ultimate surgical goal of thymectomy is to completely remove the gland and anterior mediastinal tissue without nerve injury. Bilateral concomitant video-assisted thoracic thymectomy with a contralateral surveillance camera was found feasible and safe. Given the capability of our technique to perform a complete and extensive thymectomy associated with less invasiveness and beneficial effects, there seems to be a role for minimally invasive thymectomy in the treatment of thymoma.

Near-infrared fluorescence imaging can help identify the contralateral phrenic nerve during robotic thymectomy

PURPOSE

Unilateral robotic thymectomy is gaining popularity. Identifying the contralateral phrenic nerve is a key limitation to achieving maximal thymic tissue resection. We evaluated the feasibility and technique of fluorescence imaging on the daVinci-Si robot (Intuitive Surgical Inc, Sunnyvale, CA) to identify the contralateral periocardiophrenic neurovascular bundle (PNB).

DESCRIPTION

A unilateral right robotic thymectomy was performed in 10 patients. The thymus and its poles were mobilized. Indocyanine green was injected and fluoresced to identify the left PNB in four different viewing angles to assess the view that consistently positively identified the PNB.

EVALUATION

No complications from indocyanine green or injuries to the phrenic nerve occurred. The contralateral PNB was visualized in 80% of patients from a left pleural view, infrequently from a mediastinal view, and never distal to the aortopulmonary window.

CONCLUSIONS

During right robotic thymectomy, fluorescence imaging facilitates identification of the contralateral phrenic nerve by fluorescing the pericardiophrenic vessels. It is best visualized from a left pleural view. This technology has the potential to maximize thymic tissue resection with a unilateral approach while reducing operative time and nerve injury.

Robotic-assisted thymectomy with Da Vinci II versus sternotomy in the surgical treatment of non-thymomatous myasthenia gravis: early results

BACKGROUND

The role of thymectomy in myasthenia gravis remains controversial. The remission rate 5years after surgery varies from 13 to 51% in the literature. Sternotomy is the standard technique, though unacceptable by patients because of significant esthetic sequelae. Our objective was to demonstrate that the robot-assisted technique using the Da Vinci Surgical Robot II is at least as efficient and leaves fewer scars than the standard surgical technique.

METHODS

We retrospectively reviewed the data of 31 consecutive patients suffering from myasthenia gravis who underwent surgery in our center from January 1998 to March 2010. Ten patients with thymoma were excluded from this study. Two groups were formed: group 1 corresponding to patients treated with sternotomy, group 2 patients with robot-assisted technique. The duration of the hospital stay, the pain on D1, the degree of improvement at 1year according to Myasthenia Gravis Foundation of America (MGFA) classification, the frequency of relapses, and perioperative treatment were studied.

RESULTS

Our sample consisted of 14 women and seven men. The mean age was 31.3years. The mean delay before surgery was 24months. Group 1 included 15 patients and group 2 had six patients. The complete remission rate at 1year was 9.5% (n=2). Surgery decreased the frequency of relapses after surgery (P=0.08) equally in the two groups. The duration of hospital stay and the pain level on D1 in group 2 were significantly lower than those in group 1 (P=0.02 and P<0.001). The degree of postoperative improvement was not significantly different between the two groups (P=0.31).

CONCLUSION

The results at 1year are fully comparable for sternotomy and the robot-assisted technique. The robot provides additional benefits of minimally invasive techniques: minimal esthetic sequelae in often young patients, less parietal morbidity (including pain), shorter hospital stays. Our complete remission rate, lower than those in the literature, must be considered taking into account the early nature of these results. The surgical robot, because of its many advantages, appears to be a promising technique and should facilitate the early management of these patients.