Thoracoscopic Thymectomy with the da Vinci Robotic System for Myasthenia Gravis

Robotic Thymectomy for Myasthenia Gravis: Analysis of the Surgical and Neurological Outcomes After a 20 Years' Experience

BACKGROUND

Evidence supporting robotic thymectomy for myasthenia gravis is generally based on small sample-size studies, heterogeneous in patient selection and in reporting outcomes. Therefore, this study was conducted to assess the surgical and neurological outcomes of robotic thymectomy in myasthenic patients and to identify prognostic factors associated with symptoms' remission through a large cohort of patients operated in a 20 years' period.

METHODS

A retrospective analysis of a prospectively maintained database was conducted for all patients undergoing robotic thymectomy for myasthenia gravis between 2002 and 2022. Myasthenia Gravis Foundation of America (MGFA) recommendations were used to report the neurological outcomes. Complete remission and overall improvement were evaluated using Cumulative Incidence Functions, while the effect of preoperative variables on the probability of remission was estimated with Cox models.

RESULTS

In total, 267 patients underwent robotic thymectomy. Median operative time was 135 min and there were 7 (2.6%) open conversions. Clinical follow-up (median 83 months) showed a 5-year probability of complete remission of 18% and of overall improvement of 84%. Complete remission was negatively associated with age (HR 0.97, 95% CI 0.95-0.99, p = 0.001) and preoperative use of pyridostigmine (HR 0.34, 95% CI 0.15-0.81, p = 0.014), while severe MGFA class did not reach significance (HR 0.55, 95% CI 0.3-1.01, p = 0.052). Instead, there was a benefit in patients operated on in later years (HR 1.11, 95% CI 1.04-1.18, p = 0.01).

COMMENT

Robotic thymectomy is a safe procedure. Long-term neurological follow-up demonstrated an improvement in most patients, also in subgroups that historically showed worse outcomes.

Surgical and Neurological Outcomes in Robotic Thymectomy for Myasthenic Patients with Thymoma

BACKGROUND

While the safety and feasibility of robotic thymectomy have been well documented through several studies, the surgical and long-term neurological outcomes in patients with thymomatous myasthenia gravis (MG), particularly in advanced stages, remain scarce. This study aims to evaluate the surgical outcomes in patients undergoing robotic-assisted thymectomy (RATS) for thymoma and to analyze neurological outcomes in patients with myasthenia.

MATERIAL AND METHODS

Out of 128 robotic thymectomies performed at our institution between October 2013 and January 2022, clinical and pathological data from 55 patients diagnosed with thymoma were reviewed. Of these, thirty (54.5%) patients had concomitant acetylcholine-receptor-antibody-associated MG. Neurological outcomes were assessed using the Myasthenia Gravis Foundation of America post-intervention score (MGFA-PIS).

RESULTS

Thirty-nine (70.9%) procedures were performed using the left-sided approach. The mean operative time was 196.9 ± 79.9 min in patients with MG compared to 175.8 ± 61.6 min in non-MG patients (p = 0.285). Additionally, patients with MG had a longer in-hospital stay (4.8 ± 2.6 vs. 3.3 ± 2.2 days, p = 0.01) and a significantly higher need for intensive care unit admission (p < 0.01). No deaths were reported. The rates of conversions (3.3% vs. 4.0%, p = 0.895) and complications (p = 0.813) were comparable between the myasthenic and non-myasthenic thymomas. A multivariable analysis identified lung involvement (p = 0.023), vascular involvement (p = 0.04), and extended resection (p = 0.019) as significant risk factors for conversion and complications. The mean age of surgery for patients with MG was 54.5 ± 15.9 years. After a mean follow-up period of 35.6 ± 25.7 months, 18 (60%) patients with myasthenia showed clinical improvement of their condition. Specifically, 2 patients (6.6%) achieved complete stable remission (CSR), 2 (6.6%) experienced pharmacological remission (PR), 12 (40.0%) demonstrated minimal manifestation (MM), and 4 (13.3%) exhibited a combination of PR and MM. Twelve patients (40%) exhibited no changes, maintaining a stable clinical condition. No clinical worsening was observed. The overall improvement rates at 2 years and 5 years were 38% and 83%, respectively.

CONCLUSIONS

RATS thymectomy is a safe and feasible approach for patients with thymoma. Patients with coexisting MG may benefit through a good rate of neurological improvement.

[Robotics in thoracic surgery]

The increasing diffusion of the robotic-assisted technique in thoracic surgery (RATS) in Germany was initially delayed in comparison with other countries. Therefore, there is a large potential to implement the volume of the surgical procedures performed by RATS.The RATS-technique has many positive aspects. For example, the angulated instruments allow a full wristed dexterity like the human hand, but with a greater range of motion. The surgical Robot has a tremor filter and replicates perfectly the surgeon's movements. Furthermore, the 3D-scope enables an image magnification up to 10 times compared to the normal thoracoscopes. The RATS has also some disadvantages. For example, the operating surgeon sits far away from the patient and is not sterile while performing surgery. This is an important factor in in case of emergency situations, like major bleeding, which often require a conversion to thoracotomy.All robotic systems are built after the same master-slave technology, that allows the operating surgeon to have full control of the master system. The slave system consists of mechanical actuators that respond to the master system's inputs, so the surgical robot will translate every single movement of the surgeon at the console.The main surgical indications for RATS are: mediastinal tumors, diaphragm plication and anatomical lung resection like segment resections, lobectomies or sleeve resections.In the future, the implementation of virtual and augmented reality is expected in the training but also in the planning of RATS-operations.

Robotic Mediastinal Tumor Resections: Position and Port Placement

This study aimed to determine the optimal position and port placement during robotic resection for various mediastinal tumors. For anterior mediastinal tumors, total or extended thymectomy is commonly performed in the supine position using the lateral or subxiphoid approach. Although it is unclear which approach is better during robotic thymectomy, technical advantages of subxiphoid approach are beneficial for patients with myasthenia who require extended thymectomy. Partial thymectomy is performed in the supine position using a lateral approach. Superior, middle, and posterior mediastinal tumors are resected in the decubitus position using the lateral approach, whereas dumbbell tumor resection, which requires a posterior approach, can be performed in the prone position. The position and port placement should be chosen depending on the size, location, and aggressiveness of the tumor. In this study, we describe how to choose which of these different robotic approaches can be used based on our experience and previous reports.

Difficult Decisions in Minimally Invasive Surgery of the Thymus

A minimally invasive resection of thymomas has been accepted as standard of care in the last decade for early stage thymomas. This is somewhat controversial in terms of higher-staged thymomas and myasthenia gravis patients due to the prognostic importance of complete resections and the indolent characteristics of the disease process. Despite concerted efforts to standardize minimally invasive approaches, there is still controversy as to the extent of excision, approach of surgery, and the platform utilized. In this article, we aim to provide our surgical perspective of thymic resection and a review of the existing literature.

Robotic thymectomy for myasthenia gravis surgical techniques and outcomes

Myasthenia gravis (MG) is an autoimmune disorder in which antibodies are produced against post-synaptic acetylcholine receptors, thereby causing impairment of neuromuscular transmission. Diagnosis of MG is confirmed with the AChR antibody test and via an Electromyography. Although medical treatment with acetylcholinesterase inhibitors remains the main treatment of MG, in recent years thymectomy has become an integral part of the treatment algorithm. Numerous factors such as the Patient’s age, presence of AChR antibodies, or MuSK antibody, the severity of disease affect the decision of preforming the thymectomy. Historically thymectomy was preformed via sternotomy associated with significant morbidity. Advancement in the minimally invasive approaches to thymic resection has led to more acceptance of thymectomy in the management of MG. Among these approaches, robotic thymectomy is gaining popularity across the globe due to the unique advantages of the robotic platform like 3D visibility, enhanced dexterity, and wrist like articulating movements of instruments. This has led to less post-operative pain and morbidity; faster recovery and shorter hospital stay. Successful treatment of MG requires a multi-modality approach, which has led to the formation of MG teams in most academic centers, comprising of a specialist neurologist, intensivist, and thoracic surgeon. In this article, we describe the techniques and outcomes of the robotic thymectomy for MG.

[Robot-assisted thoracic surgery-Areas of application and limitations]

The proportion of robot-assisted thoracic surgery (RATS) is continuously increasing. The main areas of clinical application are anatomical lung resections with lymphadenectomy and resection of mediastinal tumors. Especially in the area of the thymus robot-assisted procedures can now be considered the gold standard. Overall, the limitations of video-assisted thoracoscopic surgery (VATS) can be overcome by the use of robot-assisted surgery and thus a larger proportion of patients can be treated with minimally invasive procedures. The safety of the RATS procedure has been repeatedly demonstrated, although it remains difficult to demonstrate scientifically measurable benefits. With the introduction of new systems on the market further technical evolution and improvement can be expected in the future.

[Robot-assisted Mediastinal Mass Resection]

In recent years, robot-assisted thoracic surgery is gaining more and widespread interest in Europe. Due to the narrow space and the complexity of anatomical structures, conventional minimally invasive mediastinal surgery may be challenging for the thoracic surgeon. Robot-assisted mediastinal surgery opens up new possibilities for minimally invasive surgery, as it permits greater dexterity, a three-dimensional view, and tremor adjustment, which allows the surgeon to perform complex procedures in small thoracic spaces. As robotic platforms continue to evolve, more complex mediastinal thoracic surgical interventions will be facilitated, translating to improved outcomes for patients. This article provides an overview of the current status of robot-assisted mediastinal surgery and summarises general aspects of the indication, set-up and steps of robot-assisted thoracoscopic surgery in mediastinal mass resections.

[Robotics in thoracic surgery]

The number of interventions using robot-assisted thoracic surgery (RATS) is increasing in Germany, following the previous international development. Robot-assisted surgery provides some technical advantages and can overcome existing limitations of video-assisted thoracic surgery (VATS), especially in the case of extended resections, thus enabling the proportion of minimally invasive operations to be further increased. The safety of the procedure, even in extended resections, has repeatedly been demonstrated but whether there are clinically relevant benefits from RATS is currently the subject of scientific discussions. In addition, a further technical evolution of the RATS can be postulated by the upcoming market introduction of new robotic systems.

Prognostic predictors of remission in ocular myasthenia after thymectomy

Background

Identifying prognostic predictors can assist in making clinical decisions. This study aimed to identify the potential predictors of remission in patients with ocular myasthenia gravis (OMG) after thymectomy.

Methods

OMG patients who had thymectomy between 2011 and 2017 were reviewed retrospectively. Clinical outcomes were assessed according to the Myasthenia Gravis Foundation of America Post-Intervention Status (MGFA-PIS). Kaplan-Meier analysis was used to estimate the cumulative probability of complete stable remission (CSR). Univariate and multivariable analyses with Cox proportional hazards regression were used to identify predictors of CSR.

Results

Fifty-one patients (23 male, 28 female) with a median age at OMG onset of 40 (range, 5-79) years were eligible for inclusion. Patients with thymomatous OMG (n=9) had a statistically older median age at disease onset [61 (range, 32-78) vs. 33.5 (range, 5-79) years, P=0.001], shorter duration from disease onset to thymectomy [3 (range, 2-24) vs. 10 (range, 1-132) months, P=0.004], and a higher rate of postoperative complication (44.4% vs. 9.5%, P=0.025), compared with non-thymomatous OMG (n=42). The estimated cumulative probability of CSR in the whole cohort was 41.8% (95% CI, 28.6-58.2%) 5 years after surgery. Age at onset of 40 years or younger (P=0.00016), female sex (P=0.069), and thymic hyperplasia (P=0.0061) were potential predictors under univariate analysis. However, only age at onset of 40 years or younger (HR: 4.117, 95% CI, 1.177-14.399, P=0.027) remained significant after multivariable analysis.

Conclusions

CSR could be achieved in about 40% of OMG patients 5 years after thymectomy and is likely to be predicted by age at onset of 40 years or younger.

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.

Comparing robotic and trans-sternal thymectomy for early-stage thymoma: a propensity score-matching study

OBJECTIVES

Minimally invasive techniques seem to be promising alternatives to open approaches in the surgical treatment of early-stage thymoma, although there are controversies because of lack of data on long-term results. The aim of the study was to evaluate the surgical and oncological results after robotic thymectomy for early-stage thymoma compared to median sternotomy.

METHODS

Between 1982 and 2017, 164 patients with early-stage thymoma (Masaoka I and II) were operated on by median sternotomy (108 patients) or the robotic approach (56 patients). Duration of surgery, amount of blood loss, complications, duration of chest drainage, postoperative hospital stay, oncological results and total costs were retrospectively evaluated. Data were analysed also after propensity score matching.

RESULTS

Compared to the trans-sternal group, robotic thymectomy had significantly longer average operative times (P < 0.001) but less intraoperative blood loss (P = 0.01), less perioperative complications (P = 0.03), shorter time to chest drainage removal and hospital discharge (P < 0.001). The median expense for the trans-sternal approach was significantly higher than the cost of the robotic procedure (P < 0.001), mainly due to longer hospitalization. From an oncological point of view, there were no differences in thymoma recurrence, although follow-up of the trans-sternal group was significantly longer (P < 0.001). Data were confirmed after propensity score matching.

CONCLUSIONS

Robotic thymectomy for early-stage thymoma is a technically safe and feasible procedure with low complication rate and shorter hospital stay compared to the trans-sternal approach. Cost analysis revealed lower expenses for the robotic procedure due to the reduced hospital stay. The oncological outcomes seemed comparable, but longer follow-up is needed.

Video-Assisted Thoracoscopic Versus Robotic-Assisted Thoracoscopic Thymectomy: Systematic Review and Meta-analysis

OBJECTIVE

Minimally invasive thoracic surgical procedures, performed with or without the assistance of a robot, have gained popularity over the last decade. They have increasingly become the choice of intervention for a number of thoracic surgical operations. Minimally invasive surgery decreases postoperative pain, hospital stay and leads to a faster recovery in comparison with conventional open methods. Minimally invasive techniques to perform a thymectomy include video-assisted thoracoscopic surgery (VATS) or robotic-assisted thoracoscopic surgery (RATS). In this study, we aim to systematically review and interrogate the literature on minimally invasive thymectomy and draw a meta-analysis on the outcomes between the two approaches.

METHODS

An extensive electronic health database search was performed on all articles published from inception to May 2015 for studies describing outcomes in VATS and RATS thymectomy.

RESULTS

A total of 350 patients were included in this study, for which 182 and 168 patients underwent RATS and VATS thymectomy, respectively. There were no recorded in-hospital deaths for either procedure. There was no statistical difference in conversion to open, length of hospital stay, or postoperative pneumonia. Operational times for RATS thymectomy were longer.

CONCLUSIONS

The VATS and RATS thymectomy offer good and safe operative and perioperative outcomes. There is little difference between the two groups. However, there is poor evidence basis for the long-term outcomes in minimally invasive procedures for thymectomy. It is imperative that future studies evaluate oncological outcomes both short and long term as well as those related to safety.

Robotic-assisted thymectomy for early-stage thymoma: a propensity-score matched analysis

The aim of this study was to analyse the feasibility and safety of robotic-assisted thymectomy (RoT) in patients with clinically early stage thymoma, investigating clinical and early oncological results. Between 1998 and 2017, we retrospectively reviewed 76 (42.2%) patients who underwent radical thymectomy for clinically early stage thymoma (Masaoka-Koga I and II), identifying all patients who underwent RoT (n = 28) or open thymectomy (OT) with eligibility criteria for robotic surgery (n = 48). Using a propensity-score matched for tumor size (3.9 ± 1.8 cm) and stage (35% stage I, 42% stage IIA, 23% stage IIB), we paired 24 patients who had RoT with 24 patients undergoing OT. RoT was left-sided in 19 (79.2%) patients. None of the patients required conversion to open surgery. OT was via sternotomy in 21 (87.5%) patients and thoracotomy in 3 (12.5%). Mean operating time was shorter in the RoT group (117 ± 40 min) than in the OT (141 ± 46 min) (p = 0.06), even if not statistically significant. Length of stay was significantly shorter in the RoT group (mean 4.0 ± 1.9 days) than in the OT (mean 5.9 ± 1.7 days) (p = 0.0009). No significant difference between the two groups regarding post-operative complications. Five patients died in the OT group after a median follow-up of 6.1 years (only one for recurrence). After a median follow-up of 1.3 years, all patients in the RoT group were alive without disease. RoT is feasible and safe for early stage thymoma with clear advantage compared to OT in term of short term outcomes. A longer follow-up is needed to better evaluate the oncological results.

Independent long-term result of robotic thymectomy for myasthenia gravis, a single center experience

Background

Robotic thymectomy has been suggested a feasible and safe approach for myasthenia gravis (MG). Few investigations have revealed the independent effect of robotic thymectomy without the confounding impact of immunosuppressive (IM) therapy.

Methods

Between May 2009 and December 2012, robotic extended thymectomy was carried out for patients with diagnosis of MG. The clinical data, subsequent neurological therapy and postintervention status were collected.

Results

Data of 37 cases was available for analysis. The mean follow-up was 70.0±13.3 months. The median age was 40 years. Twelve (32.4%) patients kept free of IM therapy, and 25 (67.6%) patients accepted postoperatively. The overall 5-year complete stable remission (CSR) rate was 40.6% and improvement rate was 81.6%. The young (age ≤40) displayed a significant better CSR rate (P=0.015) and a trend of better improvement rate (P=0.050) compared to the old (age >40). Patients without usage of IM therapy showed significant higher CSR rate (P=0.014) and improvement rate (P=0.024) compared to those with usage of IM therapy. Patients with Myasthenia Gravis Foundation of America (MGFA) classes I showed a trend of higher remission rate by multivariate analysis. No significant differences were found for the remission rate according to gender, pathology, and the duration of symptoms.

Conclusions

The mono-therapy of robotic thymectomy may bring with a satisfactory long-term result for part of MG patients. Precision selection and individualized therapy are of the most importance.

Robotically assisted thymectomy: a review of the literature

The aim of this literature review is to see where the robotic thymectomy stands nowadays. A thorough search of the PubMed revealed eighty-two related articles which reviewed comprehensively. The zero intraoperative mortality, the minimal intraoperative morbidity, as well as the recorded recurrence rate of 0-11.1% and complete stable remission rate of 0-40% suggests that the robotic-assisted thymectomy is a feasible, safe and an upcoming procedure. However, the lack of prospective randomized controlled trials prevents this technique to become the standard approach for the nonce.

Thymic minimally invasive surgery: state of the art across the world-Europe

In this brief review of selected peer-reviewed literature on thymic minimally-invasive surgery (MIS) we sought to identify if there is a unique approach to thymic MIS on the European continent.

Robotic thymectomy

Thymectomy is the most frequent surgical operation involving the mediastinum, both for the treatment of thymic tumors and for the multidisciplinary management of myasthenia gravis (MG). Different surgical approaches have been described, either traditional open approaches or minimally invasive ones. Robotic thymectomy represents a further step in the evolution of minimally invasive surgery. Available data show that robotic thymectomy may be considered a safe and feasible operation, with encouraging long-term results in myasthenic patients and promising results in patients with early stage thymoma, both in terms of surgical and oncological outcomes. We present the surgical technique of robotic thymectomy that we apply for patients affected by myasthenia gravis and early stage thymoma.

Robotic Thymectomy: Learning Curve and Associated Perioperative Outcomes

INTRODUCTION

Recently, robotic-assisted thymectomy (RAT) has emerged as an alternative to either, an open transsternal approach or to a video-assisted thoracoscopic approach, for both thymic tumors and benign lesions. We have reviewed our early experience with RAT to assess the associated learning curve as well as the short-term perioperative outcomes.

METHODS

A prospectively collected database was reviewed for patients who underwent RAT for all causes in the period 2012-2016. Robotic thymectomy cases were stratified and compared according to the number of cases performed by each surgeon (≤15 versus >15 cases). A propensity score matching was done to compare perioperative outcomes in patients undergoing robotic and transsternal resection of thymomas.

RESULTS

Seventy patients (47 females) with a median age of 52, underwent RAT. The median operative time was 102 min with 5 conversions to an open approach for local invasion (n = 3) or for complete pleural symphysis (n = 2). There were 2 rib fractures and 1 recurrent laryngeal nerve palsy. Median length of chest tube drainage and length of stay were 1 and 3 days, respectively. Operative time and estimated blood loss plateaued after surgeon's initial 15-20 cases, which may reflect the initial learning curve. A comparison between early and late robotic cases showed that with the growing experience, the operative time becomes shorter (94 versus 107 min, P = .018). Propensity score analysis between robotic and transsternal resection of thymoma (n = 22 in each group) showed no significant differences in operative time (P = .79), intraoperative complications (P = .99), or postoperative complications (P = .99).

CONCLUSIONS

Robotic thymectomy is feasible and safe, and is associated with comparable perioperative outcomes to the traditional transsternal approach in patients undergoing thymomectomy. An initial learning curve of 15-20 robotic thymectomy cases may be required by the surgeons to adequately perform this relatively novel technique.

Robotic-assisted thymectomy: current perspectives

Thymectomy is the cornerstone in the treatment of thymic tumors and an accepted option for the management of myasthenia gravis. Different surgical approaches have been described, but the gold standard is represented by median sternotomy. In the last two decades, the development of minimally invasive surgery has led to an increased acceptance of thymectomy, especially for benign diseases. Robotic thymectomy seems a further step in the development and evolution of minimally invasive approaches. Since its introduction, different authors described their experience with robotic thymectomy, both for nonthymomatous myasthenia gravis and for thymic tumors. Available data show that robotic thymectomy may be considered a safe and feasible operation. In patients with nonthymomatous myasthenia, robotic thymectomy is effective and the long-term results are encouraging. The role of robotic thymectomy in patients affected by thymoma is still under evaluation, but the intermediate results seem promising both in terms of surgical and oncologic outcomes.

Clinical outcomes of CO2-less single-port video-assisted thoracoscopic thymectomy versus open thymectomy: comparative study

BACKGROUND

Although video-assisted thoracoscopic surgery (VATS) for thymic disorders has been introduced, its oncological outcome and benefits over others open approaches remains unclear. Single-port VATS thymectomy using a flexible port and CO₂ has been described. However, VATS thymectomy is possible by a single incision of 3 cm without CO₂ insufflation or special port device avoiding objections related to CO₂ insufflation and allowing instruments to move more freely making procedure easier and cheaper. Our institutional experience in open and CO₂-less VATS single-port thymectomy was retrospectively reviewed to evaluate compared to sternotomy, the clinical and oncological outcomes with this novel approach.

METHODS

A retrospective review consisting of 84 patients who underwent thymectomy because different thymic disorders especially thymoma was performed. Eighteen patients underwent CO₂-less VATS single port thymectomy, while 66 underwent thymectomy through open sternotomy. Many clinical factors associated with the surgical and clinical outcomes, including tumor recurrence and clinical remission, were recorded.

RESULTS

Non major postoperative complications were observed in any group. The median operative time and postoperative hospital stay of CO₂-less VATS single port thymectomy were 95 min and 1 day, respectively and 120 min and 7 days for open sternotomy. The thymoma was the most common thymic disorder with 7 patients (38%) in VATS group and 28 patients (42.4%) for the open approach. The median lesion size was 2.6 cm in the VATS group and 3.2 cm in the open approach. No thymoma recurrence in patients undergoing VATS was observed during the follow-up time, while in the open surgery group 14.28% recurrence was observed, distributed as follows: loco-regional 75% and 25% at distance; free disease period of these patients was 8.3 months. Thymectomy associated with myasthenia gravis (MG) was observed in 6 (33%) patients in the VATS group and 32 (48%) patients for sternotomy; our results regarding thymectomy for the treatment of MG were established by the MG post-intervention status [complete stable remission (CSR), pharmacologic remission, minimal manifestations, improved, unchanged and worse exacerbation, and died of MG] and reflected similar results in both approaches.

CONCLUSIONS

CO₂-less VATS single-port thymectomy is a feasible and safe procedure. Oncologic outcomes are similar to open approaches. Complications, surgical time and hospital stay are shorter compared with sternotomy. This is an initial experience, further work is required to evaluate long-term results.

Endoscopic thymectomy: a neurologist's perspective

Myasthenia gravis (MG) is an autoimmune neuromuscular disease characterized by the presence of antibodies interacting at the neuromuscular junction (NMJ), resulting in loss of strength and severe exhaustibility of striated muscles. The abnormal production of these antibodies is triggered mainly in the thymus, and hence thymectomy in MG is considered a universally recommended treatment in order to improve the symptomatologic condition of this pathology. Currently, minimally invasive thymectomy using the Da Vinci robot system is certainly one of the most innovative techniques, performed in Pisa since 2001. This approach provides a valuable alternative to the traditional thymectomy through median sternotomy. The contribution of a neurologist is fundamental for preoperative patient selection and for the peri-operative clinical assistance in both approaches. We believe that in the robotic approach, the multidisciplinary collaboration between the neurologist, thoracic surgeon and anesthetist is important in reducing perioperative complications and ensuring a higher rate of complete remission or stable clinical improvement of MG.

Multi-institutional European experience of robotic thymectomy for thymoma

BACKGROUND

Robotic thymectomy for early-stage thymomas has been recently suggested as a technically sound and safe approach. However, due to a lack of data on long term results, controversy still exists regarding its oncological efficacy. In this multi-institutional series collected from four European Centres with high volumes of robotic procedures, we evaluate the results after robot-assisted thoracoscopic thymectomy for thymoma.

METHODS

Between 2002 and 2014, 134 patients (61 males and 73 females, median age 59 years) with a clinical diagnosis of thymoma were operated on using a left-sided (38%), right-sided (59.8%) or bilateral (2.2%) robotic approach. Seventy (52%) patients had associated myasthenia gravis (MG).

RESULTS

The average operative time was 146 minutes (range, 60-353 minutes). Twelve (8.9%) patients needed open conversion: in one case, a standard thoracoscopy was performed after robotic system breakdown, and in six cases, an additional access was required. Neither vascular and nerve injuries, nor perioperative mortality occurred. A total of 23 (17.1%) patients experienced postoperative complications. Median hospital stay was 4 days (range, 2-35 days). Mean diameter of resected tumors was 4.4 cm (range, 1-10 cm), Masaoka stage was I in 46 (34.4%) patients, II in 71 (52.9%), III in 11 (8.3%) and IVa/b in 6 (4.4%) cases. At last follow up, 131 patients were alive, three died (all from non-thymoma related causes) with a 5-year survival rate of 97%. One (0.7%) patient experienced a pleural recurrence.

CONCLUSIONS

Our data suggest that robotic thymectomy for thymoma is a technically feasible and safe procedure with low complication rates and short hospital stays. Oncological outcome appears to be good, particularly for early-stage tumors, but a longer follow-up period and more cases are necessary in order to consider this as a standard approach. Indications for robotic thymectomy for stage III or IVa thymomas are rare and should be carefully evaluated.

Standardized definitions and policies of minimally invasive thymoma resection

A wide range of technical approaches for the minimally invasive resection of thymus have been described. Most of the time, the benefits are superior cosmetic outcome and shorter duration of postoperative stay. Other demonstrable differences that have been reported include shorter duration of surgery, less intraoperative blood loss and less postoperative pleural drainage. Robotic surgery and video-assisted surgery (VATS) may become routinely used procedures in the treatment of stage I and II thymomas.

Robotic-Assisted Videothoracoscopic Mediastinal Surgery

BACKGROUND

Tumors of the mediastinum as well as normal thymus glands in patients with myasthenia gravis have traditionally been resected using large and morbid incisions. However, robotic-assisted mediastinal resections are gaining popularity because of the many advantages that the robot provides. However, few comprehensive reviews of the literature on robotic-assisted mediastinal resections exist.

METHODS

A systemic review of the current medical literature was performed, excluding cases related to esophageal pathology. These studies were evaluated and their findings are reported in this comprehensive review. Approximately 48 papers met the inclusion criteria for review.

RESULTS

Robotic-assisted surgical systems are increasingly being used in mediastinal resections. Based on the available literature, robotic-assisted thoracoscopic surgery in the mediastinum is feasible and safe. Robotic-assisted mediastinal surgery appears to be superior to open approaches of the mediastinum and is comparable with videothoracoscopic surgery when patient outcomes are considered.

CONCLUSIONS

Increased robotic experience and more studies, including randomized controlled trials, are needed to validate the findings of the current literature.

State of the art of robotic thymectomy

BACKGROUND

Thymectomy is a widely accepted treatment for most cases of myasthenia gravis and essential for the treatment of thymoma. The development of a minimally invasive procedure for thymectomy resulted in a variety of approaches for surgery on the thymic gland. The use of thoracoscopy-based techniques has continued to increase, including the latest advance in this field, robotic thymectomy.

METHODS

We review the rapid development and actual use of this approach by examining published reports, worldwide registries, and personal communications and by analyzing our database, which is the largest single-center experience and contains 317 thymectomies until 12/2012. The technical modifications of robotic thymectomy are also described.

RESULTS

Since 2001, approximately 3,500 robotic thymectomies have been registered worldwide. Meanwhile, the results of approximately 500 thymectomy cases have been published. Robotic thymectomy is performed most frequently through a standardized unilateral three-trocar approach. All reports describe promising and satisfactory results for myasthenia gravis. For early-stage thymoma, robotic thymectomy is a technically sound and safe procedure with a very low complication rate and short hospital stay. Oncological outcome without recurrences is promising, but a longer follow-up is needed.

CONCLUSION

The unilateral robotic technique can be considered an adequate approach for thymectomy, even with demanding anatomical configurations. Robotic thymectomy has spread worldwide over the last decade because of the promising results in myasthenia gravis and thymoma patients.

8 years' experience with robotic thymectomy for thymomas

BACKGROUND

The accuracy of a three-dimensional robotic-assisted videothoracoscopic approach may favor a radical resection of thymomas. The aim of this study was to demonstrate the feasibility of the robotic approach by reporting 8 years experience in a single referral center of surgical treatment of thymomas.

METHODS

We retrospectively analyzed all consecutive patients who underwent a thymectomy from April 2004 to April 2012. We analyzed the procedure time, morbidity, mortality, conversions, hospitalization, freedom from recurrence, time to progression, and overall survival.

RESULTS

From 2004 until 2012, a total of 138 robotic procedures for mediastinal tumors were performed in our center, of which 37 patients with a mean age of 57.3 years underwent a thymectomy for a thymoma. Histological analysis revealed four type A thymomas (10.8 %), seven type AB thymomas (18.9 %), seven type B1 thymomas (18.9 %), fourteen type B2 thymomas (37.8 %), four type B3 thymomas (10.8 %), and one thymus carcinoma (2.7 %). The Masaoka–Koga stages were as follows: stage I in twenty patients (54 %), stage IIA in five patients (13.5 %), stage IIB in eight patients (21.6 %), stage III in three patients (8.1 %), and stage IVa in one patient (2.7 %). The mean overall procedure time was 149 min (range 88–353). No surgical mortality was reported, and there were no peri-operative complications. No conversions were needed for surgical complications. In three cases, a conversion to sternotomy was preferred by the surgeon because tumor invasion in greater vessels was suspected. Two patients (5.4 %) suffered from a myasthenic crisis postoperatively and required prolonged mechanical ventilation. One patient (2.7 %) underwent a procedure for a thoracic herniation 6 months following thymectomy. The median hospitalization was 3 days. The follow-up analysis showed an overall survival of 100 % and tumor recurrence in one patient (2.7 %).

CONCLUSIONS

Robotic thymectomies are safe in patients with early-stage thymomas. Robotic surgery may also be feasible for some selected advanced thymomas.

Oncological outcomes of thoracoscopic thymectomy for the treatment of stages I-III thymomas

OBJECTIVES

Thoracoscopic thymectomy has gradually replaced conventional sternotomy for resection of thymoma; however, a thoracoscopic approach for thymoma remains controversial. We evaluated the oncological outcomes of thoracoscopic thymectomy for the treatment of stages I-III thymomas.

METHODS

Sixty-two patients who underwent thoracoscopic thymectomy for the treatment of thymoma were retrospectively reviewed between July 2005 and September 2011 at Jikei University Hospital. Surgical outcomes and pathological results between stages I+II and stage III were compared.

RESULTS

Twenty-nine patients had Masaoka stage I, 28 had stage II and 5 had stage III. Three stage III patients needed conversions to open surgery. Masaoka stage III comprised pathological type B3 in 3 patients and thymic carcinoma in 2. For all patients, the 5-year overall survival rate was 100%. Three recurrences, diagnosed as thymic carcinoma, were observed in the Masaoka stage II or III patients. The 5-year disease-free survival rate was 94.2% for all patients, 100% for Masaoka stage I, 96.1% for stage II and 37.5% (55 months) for stage III (P=0.002). The 5-year disease-free survival rate was 100% for the World Health Organization classification types A, AB and B1-3 and 0% for thymic carcinoma (P<0.0001). Significant differences were found in the 5-year disease-free survival stratified by the Masaoka stage or WHO classification, but not by surgical procedures.

CONCLUSIONS

Thoracoscopic thymectomy for Masaoka stages I and II thymomas presented acceptable oncological outcomes. Further investigation in a large series with longer follow-up is required. Masaoka stage III thymoma requires careful consideration of the approaches, including median sternotomy.

Surgical and neurologic outcomes after robotic thymectomy in 100 consecutive patients with myasthenia gravis

OBJECTIVE

Thymectomy is a well-defined therapeutic option for patients with myasthenia gravis; however, controversies still exist about the surgical approach, indication, and timing for surgery. We reviewed our experience reporting surgical and neurologic results after robotic thymectomy in patients with myasthenia gravis.

METHODS

Between 2002 and 2010, 100 patients (74 female and 26 male; median age, 37 years) underwent left-sided robotic thymectomy using the da Vinci robotic system (Intuitive Surgical, Inc, Sunnyvale, Calif). The Myasthenia Gravis Foundation of America classification was adopted for pre- and postoperative evaluation. Preoperative Myasthenia Gravis Foundation of America class was I in 10% of patients, II in 35% of patients, III in 39% of patients, and IV in 16% of patients.

RESULTS

Median operative time was 120 (60-300) minutes. No death or intraoperative complications occurred. Postoperative complications were observed in 6 patients (6%) (bleeding requiring blood transfusions in 3, chylothorax in 1, fever in 1, and myasthenic crisis in 1). Median hospital stay was 3 days (range, 2-14 days). Histologic analysis revealed 76 patients (76%) with hyperplasia, 7 patients (7%) with atrophy, 8 patients (8%) with small thymomas, and 9 patients (9%) with normal thymus; ectopic thymic tissue was found in 26 patients (26%). Clinical follow-up showed a 5-year probability of complete stable remission and overall improvement of 28.5% and 87.5%. Remission was significantly associated with preoperative I to II Myasthenia Gravis Foundation of America class (P = .02). A significant improvement rate was found in Myasthenia Gravis Foundation of America class I to II (P = .03) and AbAchR+ (P = .04). A high percentage of patients interrupted or reduced their medications.

CONCLUSIONS

Robotic thymectomy is a safe and effective procedure. We observed a neurologic benefit in a great number of patients. A better clinical outcome was obtained in patients with early Myasthenia Gravis Foundation of America class.