It is feasible to operate on pathological Masaoka stage I and II thymoma patients with video-assisted thoracoscopy: analysis of factors for a successful resection

Intercostal approach VATS is feasible for large-sized anterior mediastinal tumors

There is no consensus about whether relatively large mediastinal tumors (≥ 5.0 cm) are suitable for video-assisted thoracoscopic surgery (VATS). Therefore, this study aimed to compare the efficacy and safety of intercostal approach VATS for large-sized anterior mediastinal tumors (5.0-10.0 cm) with no invasion to the surrounding tissues and organs. A total of 129 patients with anterior mediastinal tumors who received surgery in our hospital between January 2018 and July 2022 were consecutively enrolled. Patients were divided into 2 groups based on mediastinal tumor diameter: Group A (tumor size between 1.0 and 4.9 cm) and Group B (tumor size between 5.0 and 10.0 cm). The primary endpoints were operation time, blood loss, and postoperative pain, and the secondary endpoints were the volume of drainage, drainage duration, postoperative hospital stay, and postoperative complications. Significant differences were found in the volume of drainage between the two groups (Group A: 218.4 ± 140.6, Group B: 398.9 ± 369.3, P < 0.001). However, no differences were found in operation time, blood loss, drainage duration, postoperative hospital stay and duration of postoperative oral analgesics (P > 0.05). In addition, there existed no significant differences in the postoperative complications. Intercostal approach VATS is regarded as a feasible and safe surgical method for large-sized anterior mediastinal tumors (5.0-10.0 cm) with no invasion to the surrounding tissues and organs.

The Role of [18F]FDG PET/CT in the Characterization of Thymic Epithelial Tumors at Initial Stage

Purpose: The aim of this study was to evaluate the potential role of [18F]FDG positron emission tomography/computed tomography (PET/CT) in the characterization of thymic epithelial tumors (TETs). Materials and Methods: A total of 73 patients who underwent preoperative [18F]FDG PET/CT were included in this study. Visual total score (VTS), maximum standard uptake values (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and heterogeneity index (HI) parameters were analyzed to investigate the prediction of histopathologic grade and advanced stage. Results: The cohort included 26 patients with low-grade thymoma (LGT), 36 patients with high-grade thymoma (HGT), and 11 patients with thymic carcinoma (TC). Ninety-one percent of TC had VTS >2, whereas 31% of LGT and 75% of HGT had VTS >2. SUVmax, MTV, and TLG were statistically significantly higher in the TC group than in both thymoma and HGT. Using the cutoff value of 7.25 for SUVmax, TC was differentiated from thymomas with 91% sensitivity and 74% specificity. TC had significantly lower HI values than thymomas. HI parameters showed good diagnostic ability to differentiate TC from thymoma and TC from HGT. SUVmax, MTV, and TLG were significantly higher in advanced-stage disease than in early-stage disease. Conclusions: Visual and quantitative parameters can reliably predict both advanced disease and the grade of primary tumor in TETs. Therefore, as a promising metabolic imaging method, [18F]FDG PET/CT makes important contributions to preoperative evaluation in routine clinical practice.

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.

Myasthenia is a poor prognostic factor for perioperative outcomes after robotic thymectomy for thymoma

OBJECTIVES

The goal of this study was to compare the early and intermediate surgical outcomes, including the survival of those with and without myasthenic thymoma, following robotic thymectomy.

METHODS

This is a retrospective analysis of prospectively maintained data of 111 patients who underwent robotic thymectomy for thymoma over 7 years in a thoracic surgery centre in India. We performed a comparative analysis of demographics, intraoperative variables and postoperative outcomes including survival of those with and without myasthenic thymoma.

RESULTS

Of 111 patients, 68 patients were myasthenic and 43 were non-myasthenic. The need to resect surrounding structures and conversions was greater in the myasthenic group (P = 0.02, P = 0.04). Postoperative complications were significantly higher in the myasthenic group (P = 0.02). No differences were observed in intensive care unit stay, the need for postoperative ventilation and the hospital stay. On correlation, a higher Masaoka stage [odds ratio 1.96, 95% confidence interval (CI) 1.22-3.15] and an aggressive World Health Organization histological diagnosis (odds ratio 1.58, 95% CI 1.10-2.26) were more likely in patients with myasthenia gravis. A total of 7 deaths (6.3%) occurred during the median follow-up of 4.2 years, 5 among those with myasthenic thymoma and 2 among patients with non-myasthenic thymoma. Due to the small number of deaths, there is insufficient evidence to draw any conclusion about the effect of myasthenia gravis on survival after surgery (hazard ratio 0.51, 95% CI 0.09-2.71; P = 0.43).

CONCLUSIONS

The presence of myasthenia with thymoma is associated with more adjacent structure resection, higher postoperative complications and more conversions. The use of robotic surgery for thymoma resection in patients with myasthenia could not overcome the early postoperative problems related to myasthenia gravis.

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.

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

Complete resection is the standard of care for treatment of thymic malignancies. The use of minimally invasive surgery remains controversial. We searched online databases and identified studies from 1995 to 2014 that compared minimally invasive to open thymectomy for thymic malignancies. Study end points included operative blood loss, operative time, respiratory complications, cardiac complications, length of hospital stay, R0 resection, and recurrence. We summarized outcomes across studies using random-effects meta-analysis to account for study heterogeneity. We calculated ORs for binary outcomes and standardized mean differences for continuous outcomes. We calculated incidence rate ratios for the number of recurrences, accounting for total person-time observed in each study. Of 516 potential reference studies, 30 with a total of 2038 patients met the inclusion criteria. Patients with Masaoka stage I or II thymic malignancy constituted 94.89% of those in the minimally invasive surgery (MIS) group and 78.62% of those in open thymectomy (open) group. Mean tumor size was 4.09 cm (MIS) versus 4.80 (open). Of the 1355 MIS cases, 32 were converted to open cases. Patients in the MIS group had significantly less blood loss; however, no significant differences in operating time, respiratory complications, cardiac complications, or overall complications were identified. Length of stay was shorter for patients in the MIS group. When patients with Masaoka stage I and II thymic malignancy only were analyzed, there was no difference in rate of R0 resection or overall recurrence rate. One postoperative death occurred in the open group. The results of this unadjusted meta-analysis of published reports comparing minimally invasive with open thymectomy suggest that in selected patients with thymic malignancy, minimally invasive thymectomy is safe and can achieve oncologic outcomes similar to those of open thymectomy.

Port-site implantation of Type A Masaoka Stage I thymoma after video-assisted thoracic surgery: a case report

A 60-year-old woman was referred to our hospital with an anterior mediastinal tumor measuring 3.5 cm in diameter on computed tomography (CT). We performed tumor resection by video-assisted thoracic surgery (VATS) with three ports. The final diagnosis was Type A Masaoka Stage I thymoma. On follow-up CT performed 36 months after the operation, two pleural tumors were detected at the port sites through which the forceps and ultrasonic scalpel had passed repeatedly during the operation. We therefore performed a second operation and enucleated the tumors while preserving the ribs. However, other tumor tissue was detected along the surgical marginal line during the pathological diagnosis after the operation. Surgeons should thus be aware that port-site recurrence can occur after VATS resection of Type A thymoma, despite its mild biological behavior. Wide resection of the chest wall is therefore recommended for operations of port-site recurrence after VATS thymectomy.

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.

Feasibility of thoracoscopic thymectomy for treatment of early-stage thymoma

INTRODUCTION

The objective of this study was to evaluate the feasibility of thoracoscopic thymectomy (TT) for treatment of early-stage thymoma and to compare the outcomes with those after open thymectomy (OT).

METHODS

A retrospective review of 98 patients who underwent TT or OT of Masaoka stage I-II thymoma without thymic cancer between 1996 and 2013 was performed.

RESULTS

Thoracoscopic thymectomy was performed in 67 patients, and OT was performed in 31 patients. The intraoperative blood loss amounts differed significantly between the TT group and OT group (100 vs 185 mL, P = 0.0070). The postoperative hospital stay was significantly shorter in the TT group than in the OT group (4 vs 12 days, P < 0.0001). No patient in the TT group underwent conversion to open surgery, and no surgical complications, such as massive bleeding, were observed. Two patients experienced recurrence in the TT group during the median postoperative follow-up period of 65 months. No significant differences were found in the 5-year disease-free survival rates between the two groups. There were no significant differences in disease-free survival as classified by Masaoka stage, World Health Organization type, and the extent of resection of the thymus.

CONCLUSION

Our outcome showed that TT largely reduced the degree of invasiveness. The outcome was not inferior to that of OT. The results primarily demonstrated the feasibility of TT for treatment of early-stage thymoma.

Pediatric thymomas: report of two cases and comprehensive review of the literature

PURPOSE

Thymomas are rare pediatric malignancies with indolent behavior. There are fewer than 50 reported cases and no comprehensive review. We sought to evaluate our recent experience with pediatric thymomas, and comprehensively review the extant literature.

METHODS

A systematic search of the PubMed database was performed using keywords: "thymoma", "pediatric", "juvenile", "childhood", and "child". Additional studies were identified by a manual search of the reference list.

RESULTS

We report two patients with thymomas. We identified 22 case reports or series that described 48 patients; 62 % were male, 15 % presented with myasthenia gravis. Fifty percent were Masaoka Stage I, 15 % were Stage II, 13 % were Stage III, and 23 % were Stage IV. Four patients with early stage (I or II) disease were treated with adjuvant therapies in addition to surgical excision, while five patients with late stage (III or IV) disease treated with surgical excision alone. Of studies reporting at least 2-year follow-up, survival was 71 %.

CONCLUSION

Pediatric thymomas are rare tumors with a slight male predominance. Wide variations were observed in the treatment of thymomas across all stages. Our review indicates a need for large database and multi-institutional studies to clearly elucidate clinical course, prognostic factors and outcome.