Minimally Invasive versus Open Thymectomy for Thymic Malignancies: Systematic Review and Meta-Analysis

Subxiphoid approach for robotic single-site-assisted thymectomy

OBJECTIVES

We previously reported a transthoracic approach using the da Vinci Single-Site™ platform. This study describes the outcomes of robotic single-site thymectomy via a subxiphoid approach based on our previous experiences.

METHODS

This study included patients, who underwent single-site robotic thymectomy via the subxiphoid approach between September 2018 and October 2019. A 3- to 4-cm vertical incision was made over the subxiphoid area, and the Lapsingle port with CO2 gas was introduced. After docking at the single site, a 5-mm curved cannula, 5-mm cardiere grasper and Maryland bipolar forceps or permanent cautery hook was inserted. The single-site robotic platform was used to conduct all surgical procedures except the dissection around the inferior portion of the thymic tissue performed via a thoracoscopic approach through the same incision.

RESULTS

Overall, 13 patients, including 2 with myasthenia gravis, were enrolled. The mean duration of the surgery and chest drainage were 167.3 ± 52.8 (range 73-253) min and 2.2 ± 0.9 (range 1-5) days, respectively. All surgeries were successfully completed without conversion to an open surgery, and there were no major post-surgical complications. The diagnoses based on histopathology included thymoma in 10 patients, thymolipoma in 2 patients and atypical carcinoid tumour in 1 patient with free resection margin.

CONCLUSIONS

This study demonstrated that robotic single-site-assisted thymectomy via the subxiphoid approach is a safe and technically feasible procedure. Although this initial series comprised relatively simple cases, more advanced and complex procedures can soon be performed with the advent of single-port robotic platform.

The Early Perioperative Outcomes of Subxiphoid Approach Versus Lateral Intercostal Approach Thoracoscopic Thymectomy for Thymic Tumors: A Meta-Analysis

Objectives: To systematically evaluate the early perioperative outcomes regarding the safety and efficacy of subxiphoid thoracoscopic thymectomy (STT) versus lateral intercostal thoracoscopic thymectomy (LITT) for patients with thymic tumors. Methods: A thorough literature search of the following online databases was performed: Web of Science, PubMed, Embase, Cochrane Library, Google Scholar, and ClinicalTrials.gov. Original research articles published before December 30, 2020, that compared STT with LITT were included. Meta-analysis was performed for early perioperative outcomes, including blood loss, pain score, duration of hospital stay, operative time, chest tube drainage time, and incidence of postoperative complications. Results: Six studies that included 604 patients were finally selected for our analysis, with 296 cases of STT and 308 cases of LITT. Our results showed that compared with LITT, STT was associated with less blood loss (standardized mean difference = -0.81, 95% confidence interval [CI] = -1.49 to -0.14, P = .02), a lower pain score (weighted mean difference [WMD] = -2.55, 95% CI = -3.52 to -1.59; P < .00001), and a shorter hospital stay (WMD = -1.37, 95% CI = -2.37 to -0.36; P = .008), whereas there were no significant differences with regard to the operative time (WMD = -10.04, 95% CI = -22.29 to 2.21, P = .11), chest tube drainage time (WMD = -0.58, 95% CI = -1.17 to 0.02, P = .06), and the incidence of postoperative complications (odds ratio = 0.75, 95% CI = 0.39 to 1.44, P = .38). Conclusions: The current analysis suggests that STT is superior to LITT with respect to the early perioperative outcomes, and STT is a safe and effective surgical method for patients with thymic tumors.

Extended thymectomy via subxiphoid uniportal Video-Assisted Thoracoscopic Surgery: A case report

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Minimally invasive thymectomy is the primary surgical means for myasthenia gravis.

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Subxiphoid VATS method has the benefit of less blood loss and shorter hospital stay.

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Subxiphoid surgical port placement eliminates postoperative intercostal neuralgia.

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Subxiphoid uniportal thymectomy is safe and feasible for selected patients.

Introduction and importance

Myasthenia gravis (MG) is a well-known disease in adults, but the prevalence in children population is low. One treatment option is thymectomy. Transsternal procedure have been the primary approach, but recent trends lean toward minimally invasive technique with triportal and, recently, uniportal thoracoscopic method. This is related to the suggested less blood loss and hospital length of stay.

Case presentation

Hereby we report a case of a 4-year-old boy suffering from Juvenile Myasthenia Gravis (JMG) with thymic hyperplasia who underwent extended thymectomy via subxiphoid uniportal Video-Assisted Thoracoscopic Surgery (VATS) in our hospital. Pathology evaluation reported a case of thymic hyperplasia. The postoperative outcome was uneventful and satisfactory.

Clinical discussion

Subxiphoid uniportal approach for thymectomy is relatively new and has not been widely reported. It is important to highlight its advantages and disadvantages compared to other means for thymectomy.

Conclusion

Subxiphoid uniportal VATS is a safe and feasible approach for thymectomy.

Minimally invasive thymectomy for myasthenia gravis favours left-sided approach and low severity class

OBJECTIVES

Complete thymectomy is a key component of the optimal treatment for myasthenia gravis. Unilateral, minimally invasive approaches are increasingly utilized with debate about the optimal laterality approach. A right-sided approach has a wider field of view, while a left-sided approach accesses potentially more thymic tissue. We aimed to assess the impact of laterality on perioperative and medium-term outcomes, and to identify predictors of a 'good outcome' using standard definitions.

METHODS

We performed a multicentre review of 123 patients who underwent a minimally invasive thymectomy for myasthenia gravis between January 2000 and August 2015, with at least 1-year follow-up. The Myasthenia Gravis Foundation of America standards were followed. A 'good outcome' was defined by complete stable remission/pharmacological remission/minimal manifestations 0, and a 'poor outcome' by minimal manifestations 1-3. Univariate and multivariable logistic regression analyses were performed to assess factors associated with a 'good outcome'.

RESULTS

Ninety-two percent of thymectomies (113/123) were robotic-assisted. The left-sided approach had a shorter median operating time than a right-sided: 143 (interquartile range, IQR 110-196) vs 184 (IQR 133-228) min, P = 0.012. At a median of 44 (IQR 27-75) months, the left-sided approach achieved a 'good outcome' (46%, 31/68) more frequently than the right-sided (22%, 12/55); P = 0.011. Multivariable analysis identified a left-sided approach and Myasthenia Gravis Foundation of America class I/II to be associated with a 'good outcome'.

CONCLUSIONS

A left-sided thymectomy may be preferred over a right-sided approach in patients with myasthenia gravis given the shorter operating times and potential for superior medium-term symptomatic outcomes. A lower severity class is also associated with a 'good outcome'.

Efficacy and safety of omitting chest drains after video-assisted thoracoscopic surgery: a systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to determine the efficacy and safety of omitting chest drains compared to routine chest drain placement after video-assisted thoracoscopic surgery (VATS).

METHODS

Five bibliographic databases, ClinicalTrials.gov and PROSPERO were comprehensively searched from inception to July 29, 2020 (no language restrictions). Postoperative outcomes were extracted and synthesized complying with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Risk of bias (RoB) including non-reporting bias, heterogeneity, and sensitivity were assessed. Subgroup analyses were performed based on study design.

RESULTS

Of 7,166 identified studies, 10 studies [four randomized controlled trials (RCTs) and six non-RCTs] with 1,079 patients were included. There were 561 patients in the no chest drain group (NCD) and 518 patients in the standard chest drain group (CD). In pairwise analysis the NCD group had significant shorter length of stay (LOS) [weighted mean difference (WMD) -1.53 days, P<0.001], less postoperative pain scores (WMD -1.09, P=0.002), but higher risk of drain insertion or thoracocentesis [risk radio (RR) 3.02, P=0.040]. There were no significant differences on the incidence of minor pneumothorax (RR 1.77, P=0.128), minor pleural effusion (RR 1.88, P=0.219), minor subcutaneous emphysema (RR 1.37, P=0.427) or pneumonia (RR 0.53, P=0.549). No mortality was observed in either group during the observation period (in-hospital or 30-day mortality).

CONCLUSIONS

Omitting chest drains in selected patients after VATS seems effective leading to enhanced recovery with shorter length of postoperative stay and less pain but with a higher risk of drain insertion or thoracocentesis. However, a major part of the evidence comes from observational studies with high RoB. Further RCTs are needed to improve the current evidence.

Autoimmune disorders and paraneoplastic syndromes in thymoma

Thymomas are counted among the rare tumour entities which are associated with autoimmune disorders (AIDs) and paraneoplastic syndromes (PNS) far more often than other malignancies. Through its complex immunological function in the context of the selection and maturation of T cells, the thymus is at the same time highly susceptible to disruptive factors caused by the development and growth of thymic tumours. These T cells, which are thought to develop to competent immune cells in the thymus, can instead adopt autoreactive behaviour due to the uncontrolled interplay of thymomas and become the trigger for AID or PNS affecting numerous organs and tissues within the human body. While myasthenia gravis is the most prevalent PNS in thymoma, numerous others have been described, be they related to neurological, cardiovascular, gastrointestinal, haematological, dermatological, endocrine or systemic disorders. This review article sheds light on the pathophysiology, epidemiology, specific clinical features and therapeutic options of the various forms as well as courses and outcomes of AID/PNS in association with thymomas. Whenever suitable and backed by the limited available evidence, the perspectives from both the thymoma and the affected organ/tissue will be highlighted. Specific issues addressed are the prognostic significance of thymectomy on myasthenia gravis and other thymoma-associated AID/PND and further the impact and safety of immunotherapies on AID and PND relating to thymomas.

Video-assisted thoracoscopic thymectomy is feasible for large thymomas: a propensity-matched comparison

OBJECTIVES

Video-assisted thoracoscopic thymectomy is becoming the preferable approach for early-stage thymoma. However, large thymomas are still recognized as a relative contraindication due to the possible risk of incomplete resection or capsular disruption. Thus, the aim of this study is to evaluate the feasibility of video-assisted thoracoscopic thymectomy for large thymomas.

METHODS

Patients diagnosed with Masaoka stage I-IV thymoma between April 2001 and December 2018 were retrospectively reviewed. All patients were divided into 2 groups: thymoma <5.0 cm (group A) and thymoma ≥5.0 cm (group B). Propensity score matching analysis was performed to compare postoperative results. Recurrence-free survival and overall survival were compared for oncological evaluation.

RESULTS

A total of 346 patients were included in this study. In the propensity score matching analysis, 126 patients were included both in group A and group B. There was no significant difference between these 2 groups in terms of the R0 resection rate (95.2% vs 94.4%, P = 1.000), conversion rate (1.6% vs 3.2%, P = 0.684), operation time (119.4 ± 48.4 vs 139.1 ± 46.6 min, P = 0.955), blood loss (93.2 ± 231.7 vs 100.5 ± 149.3 ml, P = 0.649), duration of chest drainage (2.7 ± 1.6 vs 2.8 ± 2.0 days, P = 0.184), length of hospitalization (5.0 ± 3.9 vs 5.2 ± 2.9 days, P = 0.628) or postoperative complications (5.9% vs 8.5%, P = 0.068). There was no significant difference between these 2 groups in terms of the overall survival (P = 0.271) and recurrence-free survival (P = 0.288).

CONCLUSIONS

Video-assisted thoracoscopic thymectomy is a safe and effective approach for large thymomas (≥5 cm) with comparable surgical and oncological results.

Long-Term Outcomes of Robotic Thymectomy in Patients With Thymic Epithelial Tumors

BACKGROUND

The long-term outcomes of robotic thymectomy for thymic epithelial tumors (TETs) are not well known, even though the early postoperative outcomes have improved. This study aimed to report the long-term survival and recurrence in patients with TETs who underwent robotic thymectomies.

METHODS

A total of 158 patients who underwent robotic thymectomy for TET and who were followed-up for more than 1 year were included in the study. The median follow-up time was 43 (interquartile range, 40) months, and 156 (98%) patients were followed completely until the end of the study period.

RESULTS

The mean age of the patients was 55.7 ± 12.7 years, and the mean size of the tumor was 4.6 ± 2.1 cm. There was no postoperative mortality and postoperative complications occurred in 7 (4.4%) patients. The median length of the postoperative hospital stay was 2 (interquartile range, 1-20) days. Thymoma was the most common cell type (n = 132, 84%), and thymic carcinoma (n = 24, 15%) and neuroendocrine tumors (n = 2, 1%) were the next most common types. Advanced stages more than stage III were identified in 15 patients (stage IIIA: n = 7, 4%; stage IVA: n = 5, 3%; and stage IVB: n = 3, 2%). The 5-year disease-specific survival was 100% in thymoma and 95% in thymic carcinoma. The 5-year recurrence-free survival was 94% in thymoma and 79% in thymic carcinoma.

CONCLUSIONS

Robotic thymectomy could achieve favorable long-term survival and recurrence rates, comparable to open or thoracoscopic thymectomy.

Surgical and Neurological Outcome of Minimally Invasive Thymectomy in Patients With Myasthenia Gravis: An Experience of 100 Cases Over 6 Years at a Tertiary Care Center in North India

BACKGROUND

Minimally invasive thymectomy (MIT) is emerging as an effective alternative to open thymectomy in the management of patients with myasthenia gravis (MG). The primary objective of our study is to assess the surgical and neurological outcome of MIT in patients with MG.

MATERIALS AND METHODS

It is a retrospective evaluation of prospectively collected data of 100 patients with MG, who underwent MIT from April 2012 to January 2018 at a tertiary care center in India. Surgical outcome was assessed for success of minimal invasive approach, conversion, perioperative morbidity, and postoperative hospital course. Neurological outcome was assessed, after at least 1 year of follow-up, according to Myasthenia Gravis Foundation of America postintervention status. Factors predicting complete stable remission (CSR) were evaluated.

RESULTS

MIT was successfully performed in 98% patients with 2% conversion. There was no mortality. Overall, 10% of patients had perioperative morbidity with 5% having exacerbation of neurological symptoms. Two of these needed postoperative ventilation, whereas 3 recovered on conservative treatment. Median operative time and hospital stay were 140 minutes and 3 days, respectively. At a median follow-up of 47 months, CSR was seen in 20% with improvement in 73.3%. Overall, 63% patients were taken off steroids and patients requiring 3 drugs decreased by 70.7%. There was significant reduction in the dosage of pyridostigmine (P<0.001), prednisolone (P<0.001), and azathioprine (P=0.002) after thymectomy. Milder disease (Myasthenia Gravis Foundation of America class 1 and 2) predicted CSR on multivariate analysis.

CONCLUSIONS

MIT is a safe and effective procedure that leads to improvement in neurological status with significant reduction in number and dosage of medications after thymectomy. Mild disease predicts CSR.

Midterm Results for Robotic Thymectomy for Malignant Disease

BACKGROUND

There are limited reports on robotic thymectomy for malignant disease. Our objectives are to review our experience and midterm outcomes.

METHODS

We reviewed a single-surgeon prospective database for patients who underwent planned robotic resection for malignancy from January 2010 to June 2019.

RESULTS

Two hundred thirteen patients underwent resection of an anterior mediastinal mass, all of which were planned for a robotic approach. Of these, 84 (39%) underwent robotic thymectomy for malignant disease. Thymoma was the most common pathology resected (68%). Median tumor size was 4.7 cm (interquartile range, 2.9-6.3), and median operative time was 81.5 minutes (interquartile range, 64-104). All except 1 patient had a complete (R0) resection (98.8%). There were 2 (2.3%) unplanned but elective conversions to open surgery, 1 of which required cardiopulmonary bypass. Median length of stay was 1 day (range, 0-9) with 1 readmission (1.2%). Major morbidity occurred in 3 patients (3.5%), and there were no 30- or 90-day mortalities. In patients with thymoma, follow-up was complete at a median of 32 months (range, 1-98), and 1 patient (1.8%) had an ipsilateral chest recurrence. To date there have been no patient deaths.

CONCLUSIONS

Robotic thymectomy for patients with malignant disease is safe with excellent perioperative outcomes. A robotic approach achieves a high rate of complete R0 resection, even for larger tumors. For patients with thymoma local recurrence is low after midterm follow-up, but longer-term analysis is needed to determine oncologic durability.

Thymic Malignancy-Updates in Staging and Management

Thymomas are relatively indolent tumors that present with locally advanced disease in 30% of the patients. Thymic carcinoma is a more aggressive histology with shorter disease-free and overall survival. Early-stage tumors are managed best with complete resection. Multimodal therapy is the standard of care for locally advanced tumors and neoadjuvant therapy may help improve respectability. Stage and complete resection are the strongest prognostic factors for long-term survival. Based on early experience, targeted and immunotherapies have shown limited promise in advanced disease.

Trans-sternotomy versus video-assisted thoracic surgery for early-stage thymoma patients: a meta-analysis

BACKGROUND

Over the years, video-assisted thoracic surgery (VATS) thymectomy has progressively replaced trans-sternotomy (TS) in early-stage thymoma (Masaoka stage I and stage II). This meta-analysis aimed to confirm the differences in the efficacies of VATS and TS approaches in early-stage thymoma patients.

METHODS

A thorough literature search of the following online databases was performed: PubMed, Cochrane Library, Web of Science, and EMBASE. Appropriate search terms, such as "thymoma or thymus neoplasms or Thymic Carcinoma" and "Video-Assisted Thoracic Surgeries or Video-Assisted Thoracoscopic", were used with MeSH search methods. Heterogeneity was assessed first with the Q-test and inconsistency index and sensitivity analysis and subgroup analysis were then used to find the source of heterogeneity.

RESULTS

We retrieved 1,228 articles, 11 articles were selected as the subjects of our research, and 1,222 patients were included in the research (666 VATS cases versus 556 TS cases). VATS caused less blood loss (P=0.02), and required shorter hospital stay (P<0.001), shorter duration of chest tube drainage (P=0.03) than TS. No obvious difference was found in operative time (P=0.14), postoperative recurrence (OR =0.81, 95% CI: 0.35-1.85, P=0.613), postoperative complications (OR =0.60, 95% CI: 0.31-1.16, P=0.129) and R0 resection (OR =0.35, 95% CI: 0.12-1.04, P=0.06), but the trend showed that more patients in the TS group achieved R0 resection.

CONCLUSIONS

For early-stage thymoma patients, VATS thymectomy seems to provide many advantages to be considered as a legitimate alternative to TS; however, when performing VATS, surgeons should pay special attention to ensure that R0 resection is achieved.

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.

[Single-utility Port Video-assisted Thoracoscopic Extended Thymectomy for Myasthenia Gravis: Report of 45 Patients]

背景与目的

胸腺切除已成为重症肌无力（myasthenia gravis, MG）治疗的重要组成部分，近年来，经电视胸腔镜（video-assisted thoracoscopic surgery, VATS）胸腺扩大切除得到广泛应用。传统VATS术式多需3个经肋间切口，本研究改良了手术入路和操作方式，现总结单操作孔VATS胸腺扩大切除治疗MG的效果。

方法

回顾性分析2017年7月-2018年12月北京医院胸外科应用单操作孔VATS行胸腺扩大切除术的45例MG患者资料，总结其手术安全性和疗效。

结果

本组45例均顺利完成胸腺扩大切除，无中转开胸、增加切口和围术期死亡，平均手术时间（141.3±39.2）min，平均术中出血量（64.2±45.5）mL，中位胸腔引流管留置时间3 d，平均胸腔引流量（890.4±439.1）mL，中位术后住院时间6 d。围术期并发症13例（28.9%），其中肌无力危象5例（11.1%），肺部并发症6例（13.3%），切口愈合不良4例（8.9%），房颤4例（8.9%），迟发性心包积血1例（2.2%）。中位随访时间18.5个月，统计术后1年的疗效，药物缓解1例（2.2%），微小症状表现18例（40.0%），改善23例（51.1%），无变化1例（2.2%），加重2例（4.4%）。

结论

单操作孔胸腔镜下胸腺扩大切除术治疗MG的手术安全性和疗效良好，围术期应注意预防肌无力危象、肺部并发症和切口并发症。

A case of atypical thymic carcinoid mimicking a paraganglioma

BACKGROUND

Thymic atypical carcinoid has high recurrence and metastasis rates due to frequent lymph node metastases. The aim of the study is to report a case of atypical thymic carcinoid mimicking a paraganglioma and to further explain the benefits of using median sternotomy (MS) approach even in thymic epithelial tumours (TETs) sized less than 5 cm.

CASE PRESENTATION

The patient was a 59-year-old asymptomatic man. During a medical check-up, positron emission tomography/computed tomography (PET/CT) showed a 4.5 cm-diameter thymus with remarkable uptake. Thoracic surgery was performed to completely remove the tumour with lymph node dissection using MS because of possible malignancy. Although MS is accepted as the standard approach for TETs, minimally invasive thoracotomy (MIT) has emerged over recent decades. Maintaining surgical safety is priority; MIT is generally selected in <5-cm-diameter tumours. Here, we considered that the tumour could be resected using MIT. However, because PET/CT showed marked uptake, we selected the MS approach. Thus, MS can be applied even for small-sized TETs.

CONCLUSION

Thymic atypical carcinoid should be considered when PET/CT shows high-uptake tumours in the anterior mediastinum. Clinicians should consider using the MS approach, even if the tumour is <5 cm.

An exploratory study of CT-guided percutaneous radiofrequency ablation for stage I thymoma

Background

Thymoma is a rare tumor that originates from thymic epithelial cells and is usually associated with myasthenia gravis. Radiofrequency ablation (RFA) is a minimally invasive and curative treatment for other tumors, but RFA has not been used for the early treatment of thymoma.

Methods

The current study included 13 patients with stage I thymoma who were not candidates for surgical resection or video-assisted thoracoscopic surgery (VATS). All patients underwent first-line CT-guided percutaneous RFA. The feasibility and therapeutic effects of the intervention were thoroughly documented.

Results

All tumors were completely ablated (13 / 13, 100%). During follow-up (median 80.5 months, range, 64.6–116.9 months), only 1 of the 13 patients had recurrence of thymoma (1 / 13, 7.7%) at 35.5 months after the initial ablation. There were no surgery-related deaths after RFA treatment. The most common complications were fever (13 / 13, 100%) and pain (13 / 13, 100%). There was only one patient who occurred severe puncture-related bleeding during the procedure that needed blood transfusion and intravascular embolization of the punctured-injured vessel.

Conclusion

CT-guided percutaneous RFA for treatment of stage I thymoma is associated with minor trauma, few complications and good treatment outcomes.

Uniportal video-assisted thoracoscopy approach to the management of non-pulmonary diseases of the chest

The use of uniportal video-assisted thoracoscopy (u-VATS) is becoming a commonly used surgical technique and can be an effective approach for the surgical treatment of many pulmonary and non-pulmonary conditions. This review article summarizes current medical evidence informing the practice of u-VATS for treating non-pulmonary conditions including hyperhidrosis, hemothorax, pleural effusion, and thymic disease.

Video-assisted thoracoscopic surgery versus open surgery for Stage I thymic epithelial tumours: a propensity score-matched study

OBJECTIVES

Video-assisted thoracoscopic surgery (VATS) has been increasingly used in the management of thymic epithelial tumours. However, its oncological efficacy remains to be proved. The purpose of this study is to compare the oncological outcomes following thoracoscopic versus open surgery in the case-matched groups of patients with early-stage thymic tumours from the Chinese Alliance for Research in Thymomas (ChART) retrospective database.

METHODS

Between 1994 and 2012, a total of 1087 patients who underwent surgery for UICC (Union for International Cancer Control) pathological Stage I tumours from the ChART retrospective database were recruited for this study. A propensity score-matched analysis was used to compare the long-term outcomes in patients who received VATS or open surgery.

RESULTS

VATS resection was performed in 271 patients (24.9%) and open surgery in 816 patients (75.1%). Before propensity score matching, the VATS group had a smaller tumour size (P = 0.002), lower grade histology (P = 0.034), lower T stage (P < 0.001) and less adjuvant therapy (P < 0.001). Propensity score matching by gender, myasthenia gravis, tumour size, histological classification, pathological T stage, extent of thymectomy, adjuvant radiotherapy and adjuvant chemotherapy identified 110 patients in each group. After matching, there was no significant difference in patient demographics, tumour characteristics or adjuvant therapy. All matched patients had R0 resection. Overall survival, disease-free survival and cumulative incidence of recurrence were only predicted by WHO histology, but not by surgical approach, in both univariable and multivariable analyses. There was no significant difference in the overall survival (85.7% vs 93.1%, P = 0.539), disease-free survival (92.5% vs 91.9%, P = 0.773), cumulative incidence of recurrence (7.1% vs 5.8%, P = 0.522) and improvement rate of myasthenia gravis (83.3% vs 88.2%, P = 0.589) between the 2 groups.

CONCLUSIONS

This propensity score-matched study suggests that VATS and open surgeries are associated with similar oncological outcomes for Stage I thymic epithelial tumours. Minimally invasive surgery might be an acceptable surgical approach for early-stage thymic malignancies.

Optimal management of thymic malignancies: current perspectives

Thymic epithelial tumors (TETs) belong to orphan oncology. The incidence of TETs is about 1.3–3.2 cases per million worldwide. Following pathology, evolution and prognosis are variable. The World Health Organization classification distinguishes thymomas and thymic carcinomas. TETs are composed of thymic epithelial tumoral cells and normal lymphocytes. The mean age at diagnosis is 50–60 years-old. There are no identified risk factors. TETs are frequently associated with paraneoplastic syndromes as myasthenia gravis. The complete R₀ surgical resection is the most significant prognosis factor on survival. In 2010, the French National Institute of Cancer labeled the RYTHMIC network as a specific tumor board including thoracic surgeons, oncologist, and radiation therapist to define standard of care for the management of TETs. The aim of the review was to update knowledge to optimize the standard of care.

Simultaneously thoracoscopic resection of lung cancer and anterior mediastinal lesions by video-assisted thoracoscopic surgery

Background

Video-assisted thoracoscopic surgery (VATS) has been widely applied to various types of pulmonary and mediastinal resections in recent years. However, there are still limited experiences of simultaneous thoracoscopic resection for lung cancer and mediastinal tumor. The aim of the study is to investigate the technical safety and feasibility of uniportal VATS for simultaneous resection for concurrent diseases of lung and anterior mediastinum and to compare with multiportal VATS.

Methods

From June 2014 to December 2017, all patients who underwent simultaneously thoracoscopic resection for lung cancer and anterior mediastinal mass under uniportal or multiportal VATS via the same incision were retrospectively reviewed. Study cohort was divided according to surgical approach. Perioperative outcomes, including operative time, intraoperative blood loss, and postoperative hospitalization, were compared between uniportal and multiportal VATS groups.

Results

A total of 51 patients were included in the study, of whom 33 patients had uniportal VATS and 18 patients had multiportal VATS. When compared to multiportal VATS group, uniportal VATS group had similar time of operation (149.1±49.0 vs. 159.1±58.5, P=0.518), intraoperative blood loss (103.0±184.3 vs. 105.6±80.2, P=0.956), and postoperative length of hospital stay (4.7±2.0 vs. 5.5±3.0, P=0.246). No operative deaths occurred in this study.

Conclusions

Uniportal VATS for simultaneously thoracoscopic resection for lung cancer and anterior mediastinal disease is technically safe and feasible and has comparable operative parameters with multiportal VATS.

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.

Technique for Myasthenia Gravis: Subxiphoid Approach

Kido and colleagues in 1999 used for the first time the subxiphoid approach. Recently, video-assisted thoracoscopic surgery (VATS) thymectomy has been improved for the advancement of surgical materials and new instruments. The most important aspect regarding the subxiphoid approach is the possibility to avoid the intercostal nerve damage with the consequence of a decreased use of postoperative analgesics, quite short surgical duration, fast discharge from hospital and a guarantee of successful cosmetics results.

A systematic review of robotic versus open and video assisted thoracoscopic surgery (VATS) approaches for thymectomy

Background

Median sternotomy has been the most commonly used approach for thymectomy to date. Recent advances in video-assisted thoracoscopic surgery (VATS) and robotic access with CO₂ insufflation techniques have allowed more minimally invasive approaches. However, prior reviews have not compared robotic to both open and VATS thymectomy.

Methods

A systematic review was conducted in accordance with the PRISMA guidelines using PubMed, Embase and Scopus databases. Original research articles comparing robotic to VATS or to open thymectomy for myasthenia gravis, anterior mediastinal masses, or thymomas were included. Meta-analyses were performed for mortality, operative time, blood loss, transfusions, length of stay, conversion to open, intraoperative and postoperative complication rates, and positive/negative margin rates.

Results

Robotic thymectomy is a valid alternative to the open approach; advantages include: reduced blood loss [weighted mean difference (WMD): -173.03, 95% confidence interval (95% CI): -305.90, -40.17, P=0.01], fewer postoperative complications (odds ratio: 0.37, 95% CI: 0.22, 0.60, P<0.00001), a shorter hospital stay (WMD: -2.78, 95% CI: -3.22, -2.33, P<0.00001), and a lower positive margin rate (relative difference: -0.04, 95% CI: -0.07, -0.01, P=0.01), with comparable operative times (WMD: 6.73, 95% CI: -21.20, 34.66, P=0.64). Robotic thymectomy was comparable with the VATS approach; both have the advantage of avoiding median sternotomy.

Conclusions

While randomized controlled studies are required to make definitive conclusions, current data suggests that robotic thymectomy is superior to open surgery and comparable to a VATS approach. Long-term follow-up is required to further delineate oncological outcomes.

Thoracoscopic thymectomy with partial superior vena cava resection for locally advanced thymomas

Background

Video-assisted thoracoscopic surgery (VATS) is now increasingly used for the treatment of early stage thymic malignancies. However, VATS has not been advocated for patients with locally advanced diseases. We reviewed our initial experience in VATS thymectomy with partial superior vena cava (SVC) resection for IASLC/ITMIG stage III thymic tumors.

Methods

From August 2017 to October 2018, patients who underwent VATS thymectomy with partial SVC resection were retrospectively reviewed, and peri-operative outcomes and short-term follow-up results were analyzing.

Results

Four patients with partial SVC resection via VATS were identified. All of them had pathologically confirmed IASLC/ITMIG stage III thymic tumors invading the SVC. The average of operative time was 228 minutes and mean blood loss was 88 mL. The mean duration of chest tube drainage and post-operative hospital stay were 4.5 and 7.3 days respectively. No major complication was encountered after surgery. No mortality was observed. And no recurrence was detected with the longest follow-up time of 14 months.

Conclusions

With careful patient selection and plenty surgical expertise, VATS thymectomy for locally invasive thymic tumors with limited the SVC invasion is challenging yet technically feasible.

The resident's point of view in the learning curve of thymic MIS: why should I learn it?

Minimally invasive surgery (MIS) in thoracic surgery became quite popular during the last years. The aim of introducing and performing more MIS is to reduce surgical trauma, pain and complications in patients. Training in MIS increases operative time and thus cost in theatre but thus improves with experience. For a resident, the cases should be well selected with experienced supervision in a suitable setting with supporting staff and optimal instruments. Understanding the anatomy of the lung, using simulators, and attending workshops makes the learning curve shorter.

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.

How to get the best from robotic thoracic surgery

The application of Robotic technology in thoracic surgery has become widespread in the last decades. Thanks to its advanced features, the robotic system allows to perform a broad range of complex operations safely and in a comfortable way, with valuable advantages related to low invasiveness. Regarding lung tumours, several studies have shown the benefits of robotic surgery including lower blood loss and improved lymph node removal when compared with other minimally invasive techniques. Moreover, the robotic instruments allow to reach deep and narrow spaces permitting safe and precise removal of tumours located in remote areas, such as retrosternal and posterior mediastinal spaces with outstanding postoperative and oncological results. One controversial finding about the application of robotic system is its high capital and running costs. For this reason, a limited number of centres worldwide are able to employ this groundbreaking technology and there are limited possibilities for the trainees to acquire the necessary skills in robotic surgery. Therefore, a training programme based on three steps of learning, associated with a solid surgical background and a consistent operating activity, are required to obtain effective results. Putting this highest technological innovation in the hand of expert surgeons we can assure safe and effective procedures getting the best from robotic thoracic surgery.

Minimally invasive techniques in thymic surgery: a worldwide perspective

Minimally invasive surgical techniques are important in surgical management of thymic pathologies. Traditional access techniques are being replaced with minimally invasive techniques using multiportal or uniportal approach. Adoption of minimally invasive techniques for thymic malignancies has been slow due to long term recurrence concerns. Recent studies show that minimally invasive video-assisted thoracoscopic surgery (VATS) or robotic approach to early stage thymic malignancies are associated with less intraoperative bleeding, lower rate of respiratory complications, shorter chest tube duration and shorter hospital stay. Oncologic outcomes are at least equivalent to open approach. Minimally invasive approach for benign pathologies is widely applied. There are significant variations in VATS approaches for thymus, showing a multinational interest in the issue of minimizing trauma during thymectomy. Use of robotic technology is also popular, as the retrosternal area is a narrow anatomic space to manipulate conventional instruments. The evolution of minimally invasive surgery for thymus has been possible with contribution from centers all around the world. In the current practice, various approaches are being adopted and every surgeon should prefer a technique depending on surgical preference and experience.

Video-assisted thoracic surgery for thymoma: long-term follow-up results and prognostic factors-single-center experience of 150 cases

Background

The use of video-assisted thoracic surgery (VATS) in the treatment of thymoma is becoming more and more common. The aim of this study was to evaluate safety and effectiveness of thoracoscopic treatment of thymoma and, more importantly, to report long-term follow-up results of a large single-center cohort.

Methods

A retrospective review of a prospective database was performed. In total, 150 patients who underwent VATS resection for thymoma at Peking University People's Hospital from April 2001 to November 2014 were retrospectively reviewed.

Results

Average operation time was 140.1±54.2 min, median blood loss was 50 mL (range, 10-700 mL), median post-operative drainage time was 3 days (range, 1-11 days), and median length of post-op stay was 5 days (range, 2-20 days); 134 patients (89.3%) were followed up successfully. Median follow-up was 59.5 months (range, 2-187 months). Five- and 10-year recurrence free survival (RFS) rates of entire group were 96.5% and 94.4%, respectively; 5- and 10-year RFS rates for Masaoka stages I + II were 98.1% and 98.1%, respectively; 5- and 6-year RFS rates for Masaoka stage III were 90% and 60%, respectively. One case of recurrence in five Masaoka stage IV patients was observed, and 4-year RFS was 80%. Multivariable analysis indicated that recurrence tended to occur in Masaoka stages III + IV patients (P=0.037, HR =12.69, 95% CI: 1.17-138.22) and older patients had a lower risk of recurrence (P=0.029, HR =0.87, 95% CI: 0.77-0.99). Myasthenia gravis (MG) presented in 44 patients (29.3%), of which 36 patients (81.8%) were followed up. Nine patients achieved complete remission, and 19 patients had symptom improvement after surgery. Overall response rate of MG was 77.8% (28/36).

Conclusions

VATS was a safe and effective procedure for treatment of thymomas with satisfactory prognosis. MG with thymoma treated by VATS had comparable neurological outcome to that associated with the trans-sternal approach.

Spontaneous ventilation thoracoscopic thymectomy without muscle relaxant for myasthenia gravis: Comparison with "standard" thoracoscopic thymectomy

OBJECTIVES

Myasthenia gravis (MG) benefits from thymectomy. However, its unpredictable response to muscle relaxants and volatile anesthetic agents may result in muscle weakness and subsequently in postoperative myasthenic crisis. The aim of this study was to determine the surgical outcomes after spontaneous ventilation compared with conventional intubated video-assisted thoracoscopic thymectomy (spontaneous-ventilation video-assisted thoracic thymectomy [SV-VATT] vs intubated video-assisted thoracic thymectomy) in patients with MG.

METHODS

Data from all minimally invasive thymectomy procedures performed at our institute between January 2009 and June 2016 were collected. Patient characteristics, perioperative results, and treatment outcomes between SV-VATT (group 1) and the intubated video-assisted thoracic thymectomy (group 2) groups were compared. Furthermore, a propensity score-matching analysis was generated to control for selection bias due to nonrandom group assignment in a 1:1 manner.

RESULTS

Thirty-six patients were included in group 1 and 68 in group 2. Matching of patients according to propensity score resulted in a cohort that consisted of 27 patients in both groups. Patients had similar clinical characteristics in both groups. Operating time (P = .07) and lowest pulse oxygen saturation (P = .09) between the procedures were comparable after matching, but peak CO₂ level at the end of expiration was significantly greater in group 1 both before and after matching (P < .01). Moreover, the incidence of postoperative myasthenic crisis and postoperative prolonged tracheal intubation was lower in group 1. The postoperative pain visual analog scale score (P < .01) and the length of hospital stay (P = .03) were shorter in group 1.

CONCLUSIONS

SV-VATT is a feasible procedure in patients with MG. It might be beneficial by reducing postoperative myasthenic crisis and postoperative prolonged tracheal intubation. Further prospective research is needed.

Thymic minimally invasive surgery: state of the art across the world: Central-South America

Literature suggests that, for thymectomy in myasthenia or resection of thymic tumors, minimally invasive surgery is equivalent to open surgery with regard to long-term outcomes. However, it could bring some benefits in the immediate results as complication rate or length-of-stay. There are doubts about the worldwide adoption of the method, though. In Latin America, the implementation of video-assisted thoracic surgery (VATS) started in the 1990s, but it progressed slowly. The main barriers were associated costs and training. Thymic surgery poses a bigger challenge due to its rarity, so just a few reports mention the use of the method in the region. Nonetheless, in recent years we observe a faster dissemination of the method both in number and in complexity of the procedures performed. Confirming this fact, half of the patients registered in the Brazilian Society of Thoracic Surgery database in the last 2 years as undergoing resection of thymic tumors, underwent a minimally invasive procedure. Although promising, robotic surgery is still in its early days in Latin America.

VATS thymectomy for early stage thymoma and myasthenia gravis: combined right-sided uniportal and left-sided three-portal approach

The traditional approach to thymectomy requires median sternotomy based on the assumption that it is the best means to achieve adequate resection margins, complete removal of the thymus and clearance of the anterior mediastinal fat. However, in recent years, VATS thymectomy has been gaining acceptance as a means to achieve adequate oncologic results and symptomatic improvement of myasthenic symptoms with less impact on the patient. We have adopted a flexible approach based on the location of the tumor and on whether the patient has myasthenia gravis (MG) or not when planning minimally invasive VATS thymectomy. A preferential approach from the left side is chosen for clinical stage I-II thymomas located on the left side or on the midline in patients without MG, and a bilateral approach (uniportal VATS on the right side and three-portal VATS on the left side) for MG patients with or without thymoma in order to achieve complete clearance of the anterior mediastinal fat on both sides. Such techniques are herewith clearly illustrated in hope that surgeons wishing to endeavor in such an effort will be facilitated.

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.

Thymectomy is a beneficial therapy for patients with non-thymomatous ocular myasthenia gravis: a systematic review and meta-analysis

Ocular myasthenia gravis, an autoimmune disease, is characterized by extraocular muscle weakness. Myasthenia gravis is closely associated with the functional status of the thymus gland. The efficacy of thymectomy for non-thymomatous ocular myasthenia gravis remains controversial. Here, we present the first systematic review and meta-analysis of studies assessing the outcome of thymectomy in patients with non-thymomatous ocular myasthenia gravis and found that the pooled rate of complete stable remission was 0.5074 with considerable heterogeneity. Furthermore, subgroup analysis showed that the efficacy of thymectomy differed according to geographical location. Furthermore, thymectomy outcomes are better in children than they are in adults. Thymectomy clearly represents an effective treatment for patients with non-thymomatous ocular myasthenia gravis. However, more multicenter, randomized, controlled clinical trials are now required to confirm these conclusions.

Long-term outcomes of 307 patients after complete thymoma resection

Background

Thymoma is an uncommon tumor without a widely accepted standard care to date. We aimed to investigate the clinicopathologic variables of patients with thymoma and identify possible predictors of survival and recurrence after initial resection.

Methods

We retrospectively selected 307 patients with thymoma who underwent complete resection at the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (Beijing, China) between January 2003 and December 2014. The associations of patients’ clinical characteristics with prognosis were estimated using Cox regression and Kaplan–Meier survival analyses.

Results

During follow-up (median, 86 months; range, 24–160 months), the 5- and 10-year disease-free survival (DFS) rates were 84.0% and 73.0%, respectively, and the 5- and 10-year overall survival (OS) rates were 91.0% and 74.0%, respectively. Masaoka stage (P < 0.001), World Health Organization (WHO) histological classification (P < 0.001), and postoperative radiotherapy after initial resection (P = 0.006) were associated with recurrence (52/307, 16.9%). Multivariate analysis revealed that, after initial resection, WHO histological classification and Masaoka stage were independent predictors of DFS and OS. The pleura (25/52, 48.0%) were the most common site of recurrence, and locoregional recurrence (41/52, 79.0%) was the most common recurrence pattern. The recurrence pattern was an independent predictor of post-recurrence survival. Patients with recurrent thymoma who underwent repeated resection had increased post-recurrence survival rates compared with those who underwent therapies other than surgery (P = 0.017).

Conclusions

Masaoka stage and WHO histological classification were independent prognostic factors of thymoma after initial complete resection. The recurrence pattern was an independent predictor of post-recurrence survival. Locoregional recurrence and repeated resection of the recurrent tumor were associated with favorable prognosis.