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

Early Clinical Outcomes of Thoracoscopic Major Pulmonary Resection and Thymectomy Using Novel Articulating Endoscopic Forceps

Background

Video-assisted thoracoscopic surgery (VATS) is recognized as a safe and effective treatment modality for early-stage lung cancer and anterior mediastinal masses. Recently, novel articulating instruments have been developed and introduced to endoscopic surgery. Here, we share our early experiences with VATS major pulmonary resection and thymectomy performed using ArtiSential articulating instruments.

Methods

At the Seoul Metropolitan Government-Seoul National University Boramae Medical Center, 500 patients underwent VATS pulmonary resection between July 2020 and April 2023, while 43 patients underwent VATS thymectomy between January 2020 and April 2023. After exclusion, 224 patients were enrolled for VATS major pulmonary resection, and 38 were enrolled for VATS thymectomy. ArtiSential forceps were utilized in 35 of the 224 patients undergoing pulmonary resection and in 12 of the 38 individuals undergoing thymectomy. Early clinical outcomes were retrospectively analyzed.

Results

No significant differences were observed in sex, age, surgical approach, operation time, histological diagnosis, or additional procedures between the patients who underwent surgery using novel articulating instruments and the group treated with conventional endoscopic instruments for both VATS major pulmonary resection and thymectomy. However, the use of the novel articulating endoscopic forceps was associated with a significantly larger number of dissected lymph nodes (p=0.028) and lower estimated blood loss (p=0.009) in VATS major pulmonary resection.

Conclusion

Major pulmonary resection and thymectomy via VATS using ArtiSential forceps were found to be safe and effective, with early clinical outcomes comparable to established methods. Further research into long-term clinical outcomes and cost-effectiveness is warranted.

Relevance of robotic surgery for thymoma: a narrative review

Background and Objective

Thymectomy with median sternotomy is the gold standard for thymoma and myasthenia gravis, although minimally invasive procedures such as robot-assisted surgery have recently become more common. However, the superiority of these approaches has not been established, and they are infrequently recommended for localized lesions. The International Thymic Malignancies Interest Group warned that despite the perceived reduction in length of hospital stay and pain, the benefits of these approaches compared to the open approach have not been fully substantiated and that prospective collaborative data collection is critical in defining the value of these techniques. Whether thymectomy is necessary for stage I thymomas in the absence of myasthenia gravis or anti-acetylcholine receptor antibodies is also unclear. This study reviews and discusses the literature on this subject.

Methods

A narrative review was conducted using PubMed and Scopus databases. Original research articles comparing robotic to video-assisted thoracic surgery or to open thymectomy for thymomas were included. A comparison of partial resection and total thymectomy (thymothymectomy) for thymomas was also conducted.

Key Content and Findings

Perioperative outcomes such as blood loss, operative duration, complications, and length of hospital stay were better for robot-assisted resection of early-stage thymomas than for open thymoma surgery. It would be premature to consider partial resection as an appropriate treatment option for thymomas.

Conclusions

Robotic thymothymectomy is safe with effective and promising long-term results and oncological and surgical outcomes in patients with thymoma. Robotic thymectomy can become the standard procedure in patients with early-stage thymomas.

Robotic thymectomy in thymic tumours: a multicentre, nation-wide study

OBJECTIVES

Robotic thymectomy has been suggested and considered technically feasible for thymic tumours. However, because of small-sample series and the lack of data on long-term results, controversies still exist on surgical and oncological results with this approach. We performed a large national multicentre study sought to evaluate the early and long-term outcomes after robot-assisted thoracoscopic thymectomy in thymic epithelial tumours.

METHODS

All patients with thymic epithelial tumours operated through a robotic thoracoscopic approach between 2002 and 2022 from 15 Italian centres were enrolled. Demographic characteristics, clinical, intraoperative, postoperative, pathological and follow-up data were retrospectively collected and reviewed.

RESULTS

There were 669 patients (307 men and 362 women), 312 (46.6%) of whom had associated myasthenia gravis. Complete thymectomy was performed in 657 (98%) cases and in 57 (8.5%) patients resection of other structures was necessary, with a R0 resection in all but 9 patients (98.6%). Twenty-three patients (3.4%) needed open conversion, but no perioperative mortality occurred. Fifty-one patients (7.7%) had postoperative complications. The median diameter of tumour resected was 4 cm (interquartile range 3-5.5 cm), and Masaoka stage was stage I in 39.8% of patients, stage II in 56.1%, stage III in 3.5% and stage IV in 0.6%. Thymoma was observed in 90.2% of patients while thymic carcinoma occurred in 2.8% of cases. At the end of the follow-up, only 2 patients died for tumour-related causes. Five- and ten-year recurrence rates were 7.4% and 8.3%, respectively.

CONCLUSIONS

Through the largest collection of robotic thymectomy for thymic epithelial tumours we demonstrated that robot-enhanced thoracoscopic thymectomy is a technically sound and safe procedure with a low complication rate and optimal oncological outcomes.

Advantages of robot-assisted resection of large mediastinal tumors: a single-center preliminary study

Current study aims to assess the safety and efficacy of robot-assisted thoracoscopic surgery (RATS) for sizable mediastinal masses with a minimum diameter ≥6 cm, compared with video-assisted thoracoscopic surgery (VATS) and open surgery. This study enrolled 130 patients with mediastinal tumors with no less than 6 cm diameter in Zhongnan Hospital, Wuhan University, including 33 patients who underwent RATS, 52 patients who underwent VATS and 45 patients who underwent open surgery. After classifying based on mass size and whether it has invaded or not, we compared their clinical characteristics and perioperative outcomes. There was no significant difference in age, gender, mass size, myasthenia gravis, mass location, pathological types (p > 0.05) in three groups. Patients undergoing open surgery typically presenting at a more advanced stage (p < 0.05). No obvious difference was discovered in the average postoperative length of stay, operation duration, chest tube duration and average postoperative day 1 drainage output between RATS group and VATS group (p > 0.05), while intraoperative blood loss in RATS group was significantly lower than VATS group (p = 0.046). Moreover, the postoperative length of stay, operation duration, chest tube duration and intraoperative blood loss in RATS group were significantly lower than open surgery group (p < 0.001). RATS is a secure and efficient approach for removing large mediastinal masses at early postoperative period. In comparison with VATS, RATS is associated with lower intraoperative blood loss. Compared with open surgery, RATS is also associated with shorter postoperative length of stay, operation duration, chest tube duration and intraoperative blood loss.

Perioperative outcomes and survival of modified subxiphoid video-assisted thoracoscopic surgery thymectomy for T2-3 thymic malignancies: A retrospective comparison study

OBJECTIVE

Our previous study demonstrated that modified subxiphoid video-assisted thoracic surgery thymectomy with an auxiliary sternal retractor is feasible for locally invasive thymic malignancies. This study aimed to compare perioperative and oncological outcomes of modified subxiphoid video-assisted thoracoscopic surgery thymectomy versus median sternotomy thymectomy for locally advanced thymic malignancies.

METHODS

In total, 221 patients with T2-3 thymic malignancies who underwent modified subxiphoid video-assisted thoracoscopic surgery thymectomy or median sternotomy thymectomy between 2015 and 2020 were enrolled in our prospectively maintained database. A 1:1 propensity score-matching analysis was performed to balance the bias. Surgical difficulty was evaluated with a modified resection index. Perioperative and oncological results were compared between the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group and the median sternotomy thymectomy group.

RESULTS

There were 72 patients in each group in the final analysis. Our results showed that the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group had a shorter operative duration (98 vs 129 minutes, P < .001), less blood loss (40 vs 100 mL, P < .001), shorter drainage duration (3 vs 5 days, P < .001), shorter length of hospital stay (5 vs 6 days, P < .001), and fewer postoperative complications (5.6% vs 23.6%; P = .005). No significant difference was detected in complete resection (98.6% vs 98.6%, P = 1.000) between the 2 groups. Conversion occurred in 5 of 106 patients (4.7%). Survival analyses indicated similar recurrence-free survival (hazard ratio, 0.94; 95% CI, 0.40-2.20; P = .883) and overall survival (hazard ratio, 0.52; 95% CI, 0.05-5.02; P = .590) between the 2 groups.

CONCLUSIONS

Modified subxiphoid video-assisted thoracoscopic surgery thymectomy was safe and effective for T2-3 thymic malignancies and could be an alternative for selected patients with locally advanced thymic diseases. Further prospective studies are needed to evaluate the long-term survival of those undergoing modified subxiphoid approach thoracoscopic thymectomy.

Update on thymic epithelial tumors: a narrative review

Background and Objective

Thymoma, thymic carcinoma and thymic neuroendocrine tumors originate from the epithelial cells of the thymus and account for the thymic epithelial tumors (TETs). Although TETs are uncommon, they are the most frequent tumor type in the anterior mediastinum. Multidisciplinary approach is essential for their correct management. The aim of the present review is to summarize the update management for TETs.

Methods

For this review, we searched in Excerpta Medica database (EMBASE) and MEDLINE until 6 September 2023. The terms used in the search included thymoma, thymic carcinoma, thymic epithelial tumors, management, immunotherapy, multiple tyrosine kinases inhibitors.

Key Content and Findings

The therapeutic approach is based on histology and tumor stage and may involve surgery with or without neoadjuvant or adjuvant treatment. In the metastatic setting, platinum-based chemotherapy is the standard of care and patients who do not respond to first-line treatment have limited treatment options mainly because of the poor efficacy shown in subsequent lines of therapy.

Conclusions

Future research should focus on identifying predictive biomarkers for patients with TETs, and should implement multicenter collaborations and appropriate clinical trials tailored for rare tumor types. Immune check point inhibitors, mammalian target of rapamycin (mTOR) and antiangiogenic multikinase inhibitors have also been studied in this clinical setting.

Is Minimally Invasive Resection of Large Thymoma Appropriate?

BACKGROUND

Current practice patterns suggest open rather than minimally invasive (MIS) approaches for thymomas >4 cm. We hypothesized there would be similar perioperative outcomes and overall survival between open and MIS approaches for large (>4 cm) thymoma resection.

METHODS

The National Cancer Database was queried for patients who underwent thymectomy from 2010 to 2020. Surgical approach was characterized as either open or MIS. The primary outcome was overall survival and secondary outcomes were margin status, and length of stay (LOS). Differences between approach cohorts were compared after a 1:1 propensity match.

RESULTS

Among 4121 thymectomies, 2474 (60%) were open and 1647 (40%) were MIS. Patients undergoing MIS were older, had fewer comorbidities, and had smaller tumors (median; 4.6 vs 6 cm, P < .001). In the unmatched cohort, MIS and open had similar 90-day mortality (1.1% vs 1.8%, P = .158) and rate of positive margin (25.1% vs 27.9%, P = .109). MIS thymectomy was associated with shorter LOS (2 (1-4) vs 4 (3-6) days, P < .001). Propensity matching reduced the bias between the groups. In this cohort, overall survival was similar between the groups by log-rank test (P = .462) and multivariate cox hazard analysis (HR .882, P = .472). Multivariable regression showed shorter LOS with MIS approach (Coef -1.139, P < .001), and similar odds of positive margin (OR 1.130, P = .150).

DISCUSSION

MIS has equivalent oncologic benefit to open resection for large thymomas, but is associated with shorter LOS. When clinically appropriate, MIS thymectomy may be considered a safe alternative to open resection for large thymomas.

Robotic portal resection for mediastinal tumours: a prospective observational study

BACKGROUND

To demonstrate the effectiveness and feasibility of robotic portal resection (RPR) for mediastinal tumour using a prospectively collected database.

METHODS

Data from 73 consecutive patients with mediastinal tumours who underwent RPRs were prospectively collected from August 2018 to April 2023. All patients underwent chest and abdominal enhanced computed tomography (CT) and preoperative multidisciplinary team (MDT) discussion. The patients were stratified into two groups based on tumour size: Group A (tumour size < 4 cm) and Group B (tumour size ≥ 4 cm). General clinical characteristics, surgical procedures, and short outcomes were promptly recorded.

RESULTS

All of the cases were scheduled for RPRs. One patient (1/73, 1.4%) was switched to a small utility incision approach because of extensive pleural adhesion. Two patients (2.8%) converted to sternotomy, however, no perioperative deaths occurred. Most of the tumours were located in the anterior mediastinum (51/73, 69.9%). Thymoma (27/73, 37.0%) and thymic cyst (16/73, 21.9%) were the most common diagnoses. The median diameter of tumours was 3.2 cm (IQR, 2.4-4.5 cm). The median total operative time was 61.0 min (IQR, 50.0-90.0 min). The median intraoperative blood loss was 20 mL (IQR, 5.0-30.0 ml), and only one patient (1.4%) experienced an intraoperative complication. The median length of hospital stay was 3 days (IQR, 2-4 days). Compared with Group A, the median total operative time and console time of Group B were significantly longer (P = 0.006 and P = 0.003, respectively). The volume of drainage on the first postoperative day was greater in group B than in group A (P = 0.013).

CONCLUSION

RPR is a safe and effective technique for mediastinal tumour treatment, which can expand the application of minimally invasive surgery for the removal of complicated mediastinal tumours.

Surgical treatment of thymic epithelial tumors: a narrative review

Background and Objective

Thymic epithelial tumors (TETs) are scarce neoplasms of the prevascular mediastinum. Included in this diverse category of lesions are thymomas and thymic carcinomas (TCs). Surgery is the mainstay of treatment of tumors that are deemed resectable. However, up till now, optimal surgical access has been a subject of debate. The advent of new techniques, such as video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracoscopic surgery (RATS), challenged the median sternotomy which was traditionally considered the access of choice. This review aims to demonstrate the current evidence concerning the surgical treatment of TET and to enlighten other controversial issues about surgery.

Methods

PubMed research was conducted using the terms [surgery] AND [thymic epithelial tumors] OR [thymomas] and [surgical treatment] AND [thymic epithelial tumors] OR [thymomas]. Papers concerning pediatric cases and non-English literature papers were excluded. Individual case reports were also excluded.

Key Content and Findings

Minimally invasive surgical techniques (MIST) such as VATS and RATS are increasingly applied in early-stage TET. Although numerous published studies have demonstrated better perioperative outcomes in early-stage TET, long-term follow-up data are still required to demonstrate the oncological equivalent of MIST to open surgery. Resection of stage III TET is more challenging. Thymectomy can be expanded en bloc to include the major vascular structures, lung, pleura, phrenic, or vagus nerve in these individuals. There is no agreement on the ideal surgical access and traditionally these patients underwent open sternotomy, sometimes combined with a thoracic access. Evidence concerning the treatment of stage IVA disease is mainly derived from retrospective case series which are highly heterogeneous in terms of the number of enrolled patients, histology, degree of pleural involvement, and timing of presentation.

Conclusions

New techniques in the field of minimally invasive surgery are gaining acceptance for early-stage TET but longer follow-up periods are warranted to prove their oncological outcomes. On the contrary, these techniques should be used cautiously in case of locally advanced tumors. Surgeons must not forget that the main objective is the complete resection of the lesion, which is one major predictive factor for increased survival.

Clinical study of thoracoscopic assisted different surgical approaches for early thymoma: a meta-analysis

OBJECTIVE

The efficacy and safety of subxiphoid thoracoscopic thymectomy (SVATS) for early thymoma are unknown. The purposes of this meta-analysis were to evaluate the effectiveness and safety of SVATS for early thymoma, to compare it with unilateral intercostal approach video thoracoscopic surgery (IVATS) thymectomy, and to investigate the clinical efficacy of modified subxiphoid thoracoscopic thymectomy (MSVATS) for early anterior mediastinal thymoma.

METHODS

Original articles describing subxiphoid and unilateral intercostal approaches for thoracoscopic thymectomy to treat early thymoma published up to March 2023 were searched from PubMed, Embase, and the Cochrane Library. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated and analyzed for heterogeneity. Clinical data were retrospectively collected from all Masaoka stage I and II thymoma patients who underwent modified subxiphoid and unilateral intercostal approach thoracoscopic thymectomies between September 2020 and March 2023. The operative time, intraoperative bleeding, postoperative drainage, extubation time, postoperative hospital stay, postoperative visual analog pain score (VAS), and postoperative complications were compared, and the clinical advantages of the modified subxiphoid approach for early-stage anterior mediastinal thymoma were analyzed.

RESULTS

A total of 1607 cases were included in the seven studies in this paper. Of these, 591 cases underwent SVATS thymectomies, and 1016 cases underwent IVATS thymectomies. SVATS thymectomy was compared with IVATS thymectomy in terms of age (SMD = - 0.09, 95% CI: -0.20 to - 0.03, I2 = 20%, p = 0.13), body mass index (BMI; SMD = - 0.10, 95% CI: -0.21 to - 0.01, I2 = 0%, p = 0.08), thymoma size (SMD = - 0.01, 95% CI: -0.01, I2 = 0%, p = 0.08), operative time (SMD = - 0.70, 95% CI: -1.43-0.03, I2 = 97%, p = 0.06), intraoperative bleeding (SMD = - 0.30. 95% CI: -0.66-0.06, I2 = 89%, p = 0.10), time to extubation (SMD = - 0.34, 95%CI: -0.73-0.05, I2 = 91%, p = 0.09), postoperative hospital stay (SMD = - 0.40, 95% CI: -0.93-0.12, I2 = 93%, p = 0.13), and postoperative complications (odds ratio [OR] = 0.94, 95% CI: 0.42-2.12, I2 = 57%, p = 0.88), which were not statistically significantly different between the SVATS and IVATS groups. However, the postoperative drainage in the SVATS group was less than that in the IVATS group (SMD = - 0.43, 95%CI: -0.84 to - 0.02, I2 = 88%, p = 0.04), and the difference was statistically significant. More importantly, the postoperative VAS was lower in the SVATS group on days 1 (SMD = - 1.73, 95%CI: -2.27 to - 1.19, I2 = 93%, p < 0.00001), 3 (SMD = - 1.88, 95%CI: -2.84 to - 0.81, I2 = 97%, p = 0.0005), and 7 (SMD = - 1.18, 95%CI: -2.28 to - 0.08, I2 = 97%, p = 0.04) than in the IVATS group, and these differences were statistically significant. A total of 117 patients undergoing thoracoscopic thymectomy for early thymoma in the Department of Thoracic Surgery of the Second Hospital of Jilin University were retrospectively collected and included in the analysis, for which a modified subxiphoid approach was used in 42 cases and a unilateral intercostal approach was used in 75 cases. The differences between the two groups (MSVATS vs. IVATS) in general clinical characteristics such as age, sex, tumor diameter, Masaoka stage, Word Health Organization (WHO) stage, and intraoperative and postoperative conditions, including operative time, postoperative drainage, extubation time, postoperative hospital stay, and postoperative complication rates, were not statistically significant (p > 0.05), while BMI, intraoperative bleeding, and VAS on postoperative days 1, 3, and 7 were all statistically significant (p < 0.05) in the MSVATS group compared with the IVATS group.

CONCLUSION

The meta-analysis showed that the conventional subxiphoid approach was superior in terms of postoperative drainage and postoperative VAS pain scores compared with the unilateral intercostal approach. Moreover, the modified subxiphoid approach had significant advantages in intraoperative bleeding and postoperative VAS pain scores compared with the unilateral intercostal approach. These results indicate that MSVATS can provide more convenient operation conditions, a better pleural cavity view, and a more complete thymectomy in the treatment of early thymoma, indicating that is a safe and feasible minimally invasive surgical method.

Minimally Invasive Hepatopancreatobiliary Surgery at a Large Regional Health System: Assessing the Safety of Program Expansion

BACKGROUND

Complex, minimally invasive hepatopancreatobiliary surgery (MIS HPB) is safe at high-volume centers, yet outcomes during early implementation are unknown. We describe our experience during period of rapid growth in an MIS HPB program at a large regional health system.

METHODS

During an increase in MIS HPB (60% greater from preceding year), hospital records of patients who underwent HPB surgery between 1/1/2019 and 12/31/2020 were reviewed. Operative time, estimated blood loss (EBL), conversion rates, length of stay (LOS), and perioperative outcomes were assessed.

RESULTS

267 patients' cases were reviewed. The population was 62 ± 13 years, 50% female, 90% white. MIS was more frequently performed for hepatic than pancreatic resections (59% vs 21%, P < .001). Open cases were more frequently performed for invasive malignancy in both pancreatic (70% vs 40%, P < .018) and hepatic (87% vs 70%, P = .046) resections. There was no difference in operative time between MIS and open surgery (293[218-355]min vs 296[199-399]min, P = .893). When compared to open, there was a shorter LOS (4[2-6]d vs 7[6-10]d, P < .001) and lower readmission rate (21% vs 37%, P = .005) following MIS. Estimated blood loss was lower in MIS liver resections, particularly when performed for benign disease (200[63-500]mL vs 600[200-1200]mL, P = .041). Overall 30-day mortality was similar between MIS and open surgery (1.0% vs 1.8%, P = 1.000).

DISCUSSION

During a surgical expansion phase within our regional health system, MIS HPB offered improved perioperative outcomes when compared to open surgery. These data support the safety of implementation even during intervals of rapid programmatic growth.

Perioperative outcomes comparison of robotic and video-assisted thoracoscopic thymectomy for thymic epithelial tumor: a single-center experience

BACKGROUND

The advent of robot-assisted thoracoscopic surgery (RATS) has completely revolutionized the modality of thymectomy, which could reportedly achieve equivalent efficacy compared with a minimally invasive approach. This study was conducted to further compare the perioperative outcomes between these two modalities.

METHODS

A retrospective single-center study that included patients receiving either a robotic or video-assisted thoracoscopic (VAT) thymectomy between February 2021 and January 2023 was conducted. All the patients were pathologically confirmed with thymic epithelial tumors. Clinical and pathological characteristics and perioperative outcomes were collected and compared between these two cohorts.

RESULTS

A total of 190 patients were included in this study, with 61 (32.1%) and 129 (67.9%) receiving robotic and video-assisted thymectomy, respectively. The clinicopathological characteristics were not significantly different between these 2 groups. The size of the resected specimens in the RATS cohort was larger than the VATS cohort [median (IQR), 13.0 (8.0-16.0) vs. 9.0 (6.7-12.0) cm, p < 0.001], while the procedural duration was longer for the RATS group than its counterpart [median (IQR), 105 (85-143) vs. 85 (69-115) min, p = 0.001]. Moreover, no other significant difference was observed between these two groups. Since more than half of the robotic thymectomy was performed using a subxiphoid approach, a subgroup analysis was further conducted. Similarly, the robotic group through a subxiphoid approach harbored a longer procedural duration, and the size of the specimens obtained was larger than the VATS group [median (IQR), 14.0 (11.0-16.5) vs. 12.5 (8.5-15.0) cm, p = 0.061].

CONCLUSIONS

The early clinical efficacy of robotic thymectomy was proven comparable to the established VATS approach, and such a modality might have strength when obtaining larger specimens, which could contribute to improving long-term efficacy. Despite the longer procedural duration recorded in the early stage of conducting robotic thymectomy, further accumulation would help decrease the time.

Robot versus video-assisted thoracoscopic thymectomy for large thymic epithelial tumors: a propensity-matched analysis

BACKGROUND

Both video-assisted thoracoscopic surgery (VATS) thymectomy and robot-assisted thoracoscopic surgery (RATS) thymectomy have been suggested as technically sound approaches for early-stage thymic epithelial tumors. However, the choice of VATS or RATS thymectomy for large and advanced thymic epithelial tumors remains controversial. In this study, the perioperative outcomes of VATS and RATS thymectomy were compared in patients with large thymic epithelial tumors (size ≥5.0 cm).

METHODS

A total of 113 patients with large thymic epithelial tumors who underwent minimally invasive surgery were included. Sixty-three patients underwent RATS, and 50 patients underwent VATS. Patient characteristics and perioperative variables were compared.

RESULTS

Compared with the VATS group, the RATS group experienced a shorter operation time (median: 110 min vs.130 min; P < 0.001) and less blood loss (30.00 ml vs. 100.00 ml, P < 0.001). No patients in the RATS group needed conversion to open surgery, but in the VATS series, five patients required conversion to open procedures (0% vs. 14.29%, P = 0.054). The rate of concomitant resection in the RATS group was similar to that in the VATS group (11.43% vs. 5.71%; P = 0.673). There was no significant difference between the two groups in the duration of chest tube (P = 0.587), postoperative complications (P = 1.000), and the duration of postoperative hospital stay (P = 0.141).

CONCLUSION

For large thymic epithelial tumors, RATS thymectomy can be performed safely and effectively in a radical fashion. Due to the advanced optics and precise instrument control, concomitant resections can be easily achieved in larger thymic epithelial tumors using the robotic approach.

Surgical outcomes of thoracoscopic thymectomy via the single-port subxiphoid approach versus the unilateral intercostal approach

OBJECTIVES

The purpose of this study was to explore the safety and feasibility of video-assisted thoracic surgery (VATS) total thymectomy via the single-port subxiphoid approach compared with the intercostal approach.

METHODS

From January 2018 to May 2022, patients who underwent VATS total thymectomy via the subxiphoid or unilateral intercostal approach and diagnosed with Masaoka-Koga stage I-II, non-myasthenic thymoma were included in this study. Perioperative outcomes, immediate and long-term pain evaluations were compared in a propensity score-matching analysis.

RESULTS

In total, 95 patients were included and underwent the subxiphoid approach (n = 37) and the intercostal approach (n = 58). Propensity score yielded 2 well-matched cohorts of 30 patients and there was no significant demographical imbalance between the 2 groups. Compared with the intercostal approach, the subxiphoid group demonstrated favourable perioperative outcomes including the intraoperative blood loss (P = 0.025) and the median duration of hospital stay (P = 0.083). The immediate and long-term pain evaluations revealed that the subxiphoid group reported lower visual analogue scales at postoperative 24 h and lower total doses of fentanyl bolus infusions during hospitalization (P = 0.004 and 0.018, respectively), along with lower long-term neuropathic pain scale scores (P = 0.005) than patients in the intercostal group.

CONCLUSIONS

VATS thymectomy via the single-port subxiphoid approach showed favourable perioperative outcomes compared to the intercostal approach. Moreover, the subxiphoid approach seemed both to cause minimal immediate postoperative pain and to have advantages in reducing long-term neuropathic pain compared with the intercostal approach.

Perioperative outcomes of minimally invasive surgery for large malignant thymic epithelial tumors and for total thymectomy

PURPOSE

Minimally invasive surgery (MIS) for thymic tumors is now accepted widely, in line with improved surgical techniques; however, we occasionally encounter complicated cases of large tumors or of total thymectomy requiring prolonged operative duration or conversion to an open procedure (OP). We reviewed patients registered in a nationwide database to identify the technical feasibility of MIS for thymic epithelial tumors.

METHODS

Data on patients treated surgically between 2017 and 2019 were extracted from the National Clinical Database of Japan. Clinical factors and operative outcomes were calculated by tumor diameter using trend analyses. Perioperative outcomes of MIS for non-invasive thymoma were investigated using propensity score-matched analyses.

RESULTS

MIS was performed in 46.2% of the patients. The operative duration and conversion rate increased with the tumor diameter (p < .001). After propensity score-matching, operative duration and postoperative hospital stay were shorter (p < .001), and the transfusion rate was lower (p = .007) in patients who underwent MIS than in those who underwent OP for thymomas ≥ 5 cm. Among patients who underwent total thymectomy, blood loss was less (p < .001) and the postoperative hospital stay was shorter (p < .001) in those who underwent MIS than in those who underwent OP. There were no significant differences in postoperative complications and mortality.

CONCLUSIONS

MIS is technically feasible even for large non-invasive thymomas or for total thymectomy, although the operative duration and open conversion rate increase with the tumor diameter.

The predictive value of a computed tomography-based radiomics model for the surgical separability of thymic epithelial tumors from the superior vena cava and the left innominate vein

Background

The aim of this study was to develop a radiomics machine learning model based on computed tomography (CT) that can predict whether thymic epithelial tumors (TETs) can be separated from veins during surgery and to compare the accuracy of the radiomics model to that of radiologists.

Methods

Patients who underwent thymectomy at our hospital from 2009 to 2017 were included in the screening process. After the selection of patients according to the inclusion and exclusion criteria, the cohort was randomly divided into training and testing groups, and CT images of these patients were collected. Subsequently, two-dimensional (2D) and three-dimensional (3D) regions of interest were labelled using ITK-SNAP 3.8.0 software, and Radiomics features were extracted using Python software (Python Software Foundation) and selected through the least absolute shrinkage and selection operator (LASSO) regression model. To construct the classifier, a support vector machine (SVM) was employed, and a nomogram was created using logistic regression to predict vascular inseparable TETs based on the radiomics score (radscore) and image features. To assess the accuracy of these models, area under receiver operating characteristic (ROC) curves of these models were calculated, and differences among the models were identified using the Delong test.

Results

In this retrospective study, 204 patients with TETs were included, among whom 21 were diagnosed with surgical vascularly inseparable TETs. The area under ROC curve (AUC) of the 2D model, 3D model, 2D + 3D model, and radiologist diagnoses were 0.94, 0.92, 0.95, and 0.87 in the training cohort and 0.95, 0.92, 0.98, and 0.78 in testing cohort, respectively. The Delong test revealed a significant improvement in the performance of the radiomics models compared to radiologists' diagnoses. The logistic regression selected 3 image features, namely maximum diameter of the tumor, degree of abutment of vessel circumference >50%, and absence of the mediastinal fat layer or space between the tumor and surrounding structures. These features, along with the radscore, were included to develop a nomogram. The AUCs of this nomogram were 0.99 in both the training set and testing set, and the Delong test did not find a significant difference between ROC plots of the nomogram and radiomics models.

Conclusions

The proposed radiomics model could accurately predict surgical vascularly inseparable TETs preoperatively and was shown to have a higher predictive value than the radiologists.

Early Postoperative Results after Thymectomy for Thymic Cancer: A Single-Institution Experience

BACKGROUND

Surgery for thymic cancers is considered the key of curative treatment. Preoperative patients' characteristics and intraoperative features might influence postoperative outcome. We aim to verify short-term outcomes and possible risk factors for complications after thymectomy.

METHODS

We retrospectively investigated patients undergoing surgery for thymoma or thymic carcinoma in the period between January 1, 2008, and December 31, 2021, in our department. Preoperative features, surgical technique (open, bilateral VATS, RATS), intraoperative characteristics and incidence of postoperative complications (PC) were analyzed.

RESULTS

We included in the study 138 patients. Open surgery was performed in 76 patients (55.1%), in 36 VATS (26.1%) and in 26 RATS (36.1%). Resection of one or more adjacent organs due to neoplastic infiltration was required in 25 patients. PC appeared in 25 patients (52% Clavien-Dindo grade I, 12% grade IVa). Open surgery had a higher incidence of PC (p < 0.001), longer postoperative in-hospital stay (p = 0.045) and larger neoplasm (p = 0.006). PC were significant related to pulmonary resection (p = 0.006), phrenic nerve resection (p = 0.029), resection of more than one organ (p = 0.009) and open surgery (p = 0.001), but only extended surgery of more organs was confirmed as independent prognostic factor for PC (p = 0.0013). Patients with preoperative myasthenia symptoms have a trend toward stage IVa complications (p = 0.065). No differences were observed between outcomes of VATS and RATS.

CONCLUSIONS

Extended resections are related to a higher incidence of PC, while VATS and RATS guarantee a lower incidence of PC and shorter postoperative stay even in patients that require extended resections. Symptomatic myasthenia patients might have a higher risk toward more severe complications.

Unilateral Thoracoscopic Thymectomy for Thymoma: Does Side Matter? A Single Institutional Experience

BACKGROUND

Thoracoscopic thymectomy is increasingly performed for the treatment of early stage thymoma. It is characterized by shorter postoperative hospital stay, decreased intraoperative blood loss, and fewer complications compared with transsternal thymectomy. Unilateral video-assisted thoracic surgery (VATS) thymectomy can be easily performed from either side of the thorax, because thymus is located in the middle of mediastinum. However, the side that provides better outcomes remains controversial. The purpose of this study was to compare the efficacy of right and left approaches in performing unilateral thoracoscopic thymectomy for thymoma.

METHODS

Consecutive patients affected by thymoma who underwent VATS thymectomy on either side between February 2001 and March 2020 were enrolled in the study. Clinicopathologic, surgical, and oncological outcomes were retrospectively analyzed and compared among the two surgical approaches.

RESULTS

Unilateral VATS approaches were performed on 29 patients: 12 (41%) on the left side and 17 (59%) on the right side. The mean age was 63.1 ± 11.3 years and the female/male ratio was 1.73:1. The mean operative time and the hospital stay for the left-side VATS and right-side VATS groups were, respectively, 168 ± 49.5 versus 171 ± 47.9 minutes (p = 0.9) and 3 ± 1.03 days versus 3.65 ± 1.93 days (p = 0.7). Postoperative complications occurred in one patient (3%) for left-side VATS group and one patient (3%) for right-side VATS. The 5-year disease-free survival was comparable between two groups (p = 0.74).

CONCLUSION

Unilateral VATS thymectomy in patients with thymoma can be safely and effectively performed by experienced surgeons in either side of the thorax with equivalent oncological outcomes.

Application of Artificial Intelligence in the Diagnosis, Treatment, and Prognostic Evaluation of Mediastinal Malignant Tumors

Artificial intelligence (AI), also known as machine intelligence, is widely utilized in the medical field, promoting medical advances. Malignant tumors are the critical focus of medical research and improvement of clinical diagnosis and treatment. Mediastinal malignancy is an important tumor that attracts increasing attention today due to the difficulties in treatment. Combined with artificial intelligence, challenges from drug discovery to survival improvement are constantly being overcome. This article reviews the progress of the use of AI in the diagnosis, treatment, and prognostic prospects of mediastinal malignant tumors based on current literature findings.

Thymoma and Thymic Carcinoma: Surgical Resection and Multidisciplinary Treatment

Thymoma and thymic carcinoma are the most common tumors of the anterior mediastinum and a relatively rare type of thoracic cancer. The prerequisite for surgery is clinical staging and operative evaluation, both of which are based on medical imaging. The best strategy for treating a thymic epithelial tumor is surgical resection of the organ and surrounding tissue. Thymectomy modalities vary, including open surgery and minimally invasive surgery, and surgeons have used various innovations to better meet the needs of the procedure; therefore, it is critical to select the appropriate procedure based on the patient's characteristics. Evaluation of resectability is the first step of surgical resection for thymic tumors without distant metastasis. The decision regarding unresectability should be made carefully. During subsequent chemotherapy or chemoradiotherapy, reevaluation of whether an area is resectable or not remains essential. Despite numerous technological advances in the surgical treatment of thymic tumors, several contentious issues remain, including the selection of surgical approaches for difficult cases, the selection of video-assisted thoracoscopic approaches, the evaluation of resectability, minimally invasive surgery for locally advanced thymic tumors, lymphadenectomy in thymic tumors, neoadjuvant therapy for thymic tumors, debulking surgery, and salvage surgery. In solving these problems, the surgeon's judgment, surgical experience, and surgical skills are especially important.

Minimally Invasive Thymectomy Could Be Attempted for Locally Advanced Thymic Malignancies: A Real-World Study With Propensity Score-Matched Analysis

INTRODUCTION

Increasing evidence supports minimally invasive thymectomy (MIT) for early stage thymic malignancies than open median sternotomy thymectomy (MST). Nevertheless, whether MIT could be attempted for locally advanced disease remains unclear.

METHODS

The clinical data of consecutive patients with stage T2-3NxM0 (eighth edition TNM staging) thymic malignancies who underwent MIT or MST were identified from a prospectively maintained database. The co-resected structures were rated with a resection index to evaluate surgical difficulty. The impact of surgical approach on treatment outcomes was investigated through propensity score-matched analysis and multivariable analysis.

RESULTS

From January 2008 to December 2019, a total of 128 patients were included; MIT was initially attempted in 58 (45.3%) cases, and eight (13.8%) were converted to MST during surgery. The conversion group had similar perioperative outcomes to the MST group, except for a longer operation time. After propensity score matching, the resection index scores were similar between the MIT and MST groups (3.5 versus 3.7, p = 0.773). The MIT group had considerably less blood loss (p < 0.001), fewer postoperative complications (p = 0.048), a shorter duration of chest drainage (p < 0.001), and a shorter hospitalization duration (p < 0.001) than the MST group. The 5-year freedom from recurrence rate was not different between the two groups (78.2% versus 78.5%, p = 0.942). In multivariable analysis, surgical approach was not associated with freedom from recurrence (p = 0.727).

CONCLUSIONS

MIT could be safely attempted in carefully selected patients with locally advanced thymic tumors. Conversion did not compromise the surgical outcomes. Patients may benefit from the less traumatic procedure and thus better recovery, with comparable long-term oncologic outcomes.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Post-Operative Outcomes Associated With Open Versus Robotic Thymectomy: A Propensity Matched Analysis

To compare post-operative outcomes associated with thymectomy performed using either open or robotic approaches. Retrospective cohort study from a single-center prospective registry consisting of patients undergoing thymectomy between 2000 and 2020. Patients were grouped according to surgical approach (open vs robotic). A propensity-score matching analysis was performed in a 2:1 open to robotic ratio, and surgical outcomes were evaluated. We analyzed 234 thymectomies (155 open; 79 robotic). Myasthenia gravis was present in 23.2% and 32.9% (P = 0.249) in the open and in the robotic group, respectively. All covariates were balanced in the matched groups (open n = 114; robotic n =5 9), except lesion size. The robotic approach was significantly associated with shorter surgical time (median 95 vs 65 minutes, P < 0.001), lesser clinical (21.1% vs 6.8%, P = 0.016) and surgical (11.4% vs 1.7%, P = 0.036) complications during the same hospitalization, less Clavien-Dindo grade 2 or higher complication rates (28.1 vs 15.3%, P = 0.048), chest tube duration (median: 3 vs 0 days, P < 0.001) and in-hospital length of stay (median: 5 vs 0 days, P < 0.001). Bleeding (P = 0.214), ICU length of stay (P = 0.167), reoperation rate (open, 1.8% vs robotic 0%), 90-day mortality (P = 0.341) and readmission rate post discharge (P = 0.277) were similar between the groups. In the matched population with primary thymic epithelial tumors, the completeness of resection rate was similar (open, 92.1% vs robotic 96.8%, P = 0.66.). Robotic thymectomy is associated with improved post-operative outcomes when compared to open thymectomy, without compromising the goals of oncologic surgery. Longer follow-up is needed to ensure oncologic equivalence.

Approaches and outcomes of Robotic-Assisted Thoracic Surgery (RATS) for lung cancer: a narrative review

Robotic-Assisted Thoracic Surgery (RATS) is considered one of the main issues of present thoracic surgery. RATS is a minimally invasive surgical technique allowing enhanced view, accurate and complex movements, and high ergonomics for the surgeon. Despite these advantages, its application in lung procedures has been limited, mainly by its costs. Since now many different approaches have been proposed and the experience in RATS for lungs ranges from wedge resection to pneumonectomy and is mainly related to lung cancer. The present narrative review explores main approaches and outcomes of RATS lobectomy for lung cancer. A non-systematic review of literature was conducted using the PubMed search engine. An overview of lung robotic surgery is given, and main approaches of robotic lobectomy for lung cancer are exposed. Initial experiences of biportal and uniportal RATS are also described. So far, retrospective analysis reported satisfactory robotic operative outcomes, and comparison with VATS might suggest a more accurate lymphadenectomy. Some Authors might even suggest better perioperative outcomes too. From an oncological standpoint, no definitive prospective study has yet been published but several retrospective analyses report oncological outcomes comparable to those of VATS and open surgery. Literature suggests that RATS for lung procedures is safe and effective and should be considered as a valid additional surgical option.

Continuing challenges of primary neuroendocrine tumours of the thymus: A concisereview

Primary neuroendocrine tumours of the thymus (NETTs) are exceedingly rare tumours, usually presenting around mid-life, which have a propensity towards males and smokers. They are seen more often in those with MEN-1, but multiple different genetic mutations have been found to be involved in the tumorigenesis of NETTs. Histologically, NETTs are classified according to number of mitoses, the presence of necrosis, and the presence or absence of small cell features. NETTs display a wide spectrum of behavior, and they can be incidentally found on chest imaging, on screening in MEN-1, or present with symptoms of local compression. Advanced disease and paraneoplastic syndromes are common. CT-, PET/CT-, MRI-scans, and somatostatin receptor scintigraphy are the imaging modalities of choice both for the initial assessment as well as for monitoring after treatment. For patients with localized disease, complete surgical resection with lymphadenectomy provides the best chance of long-term, disease-free survival, and can be achieved through either an open or thoracoscopic approach. While chemotherapy-regimens based on platinum, taxane, and temozolomide are used most often, the optimum chemotherapy regimen in the adjuvant and palliative settings remains unclear, as does the role of radiotherapy. Ongoing research on the most effective use of somatostatin analogues, peptide receptor radionuclide therapy (PPRT), kinase inhibitors and immunotherapy in patients with other types of advanced neuroendocrine tumours may lead to further treatment options for NETTs in the future.

Robot-assisted thymectomy in large anterior mediastinal tumors: A comparative study with video-assisted thymectomy and open surgery

BACKGROUND

The aim of this study was to evaluate the safety and effectiveness of robot-assisted thymectomy (RAT) in large anterior mediastinal tumors (AMTs) (size ≥6 cm) compared with video-assisted thymectomy (VAT) and open surgery.

METHODS

A total of 132 patients with large AMTs who underwent surgical resection from January 2016 to June 2022 were included in this study. A total of 61 patients underwent RAT, 36 patients underwent VAT and 35 patients underwent open surgery. Perioperative outcomes were compared.

RESULTS

There were no significant differences in tumor size (p = 0.141), or pathological types (p = 0.903). Compared with the open group, the RAT and VAT groups were associated with a shorter operation time (115.00 vs. 160.00, p = 0.012; 122.50 vs. 160.00, p = 0.071), and less blood loss (50.00 vs. 200.00, p < 0.001; 50.00 vs. 200.00, p < 0.001), respectively. The rate of conversion in the RAT group was similar to that in the VAT group (6.56% vs. 13.89%, p = 0.229). Concomitant resection was less frequently performed in the VAT group than in the RAT and open groups (5.56% vs. 31.15%, p = 0.040; 5.56% vs. 31.43%, p = 0.006). VAT patients had a lower drainage volume (365.00 vs. 700.00 and 910.00 mL, p < 0.001), shorter duration of chest tube (2.00 vs. 3.00 and 4.00, p < 0.001), and shorter hospital stay (5.00 vs. 6.00 and 7.00, p < 0.001) than the RAT and open groups. There was no 30-day mortality in any group. No difference was seen in R0 resection rates (p = 0.846). The postoperative complication rates were similar among the three groups (p = 0.309). Total in-hospital costs (66493.90 vs. 33581.05 and 42876.40, p < 0.001) were significantly higher in the RAT group.

CONCLUSIONS

RAT is safe and effective for the resection of large AMTs compared to VAT and open surgery. Vascular resection in RAT is technically feasible. A long-term follow-up is required.

Unilateral video-assisted thoracoscopic thymoma resection – Indications, early and mid-term results

Introduction. Thymoma is the most common tumour of the anterior mediastinum. Video-Assisted Thoracic Surgery technique of thymoma resection is spreading world-wide, but the thoracoscopic method is still contentious in many ways. Authors evaluate the early and mid-term results of a 17 years period of VATS unilateral approach at 2 Hungarian thoracic surgical centers. Method. Depending on the anatomical situation of the thymoma, we performed thymectomy, or partial thymectomy (thymomectomy) for the Masaoka–Koga I–II–III stage thymoma from the right or left side through 2 or 3 intercostal ports. We managed the operations with ultrasonic dissector and electrocauter. By using international standards we evaluated perioperative morbidity, mid-term oncological results and clinical symptoms of myasthenia. Results. 23 of the 54 patients were man, 31 were woman, the average age was 58 (26–79) years, 23 of them had myasthenia. The conversion rate was 11,5% (7/61). The average operation time was 84 (39–150) minutes. The average hospitalisation time was 5.5 (3–19) days. The average size of the thymomas was 46 (18–90) mm. The histology resulted thymoma type A in 2 cases, AB in 19 cases, B1/2/3 in 11/11/1 cases, mixed B in 10 cases. The examination of the resection line was R0/1/2 in 42/11/1 cases. The Masaoka–Koga stages were: I (17), IIA (28), IIB (2), III (7). There was 25 thymomectomies, and 29 thymectomies. In seven cases there were extension of the operation to the pericardium (2), to the lung (2), to the phrenic nerve (6), and to innominate vein (1). The in-hospital mortality over 30 day was in 1 case (1.85%). The morbidity was 11/54 (20.4%). The average follow-up time was 62.56 (5–198) months. In the group with myasthenia the effectivity of the operation was 18/21 (85.7%), including complete remission of 5/21 (23.8%). Post-thymectomy myasthenia gravis developed in 2/31 cases (6.5%). The average 5 years survival was 100%, tumour-free 5 years survival was 96%. Conclusions. The higher proportion of the thymomectomy in the early results, higher conversion rate and lower R0 proportion might be in connection with the attitude of the surgeons, with the learning curve and with the limitations of the unilateral method. After a longer follow-up time late results may become more real and comparable. Instead of unilateral VATS technique we have changed to the subxyphoideal approach of VATS because of its better visualisation.

Effect Evaluation of Subxiphoid and Intercostal Thymectomy: A Meta-Analysis and Systematic Review

Background

It still remains unclear whether subxiphoid video-assisted thoracoscopic surgery (SVATS) thymectomy is safe and reasonable. This meta-analysis aims at assessing the effectiveness and safety of SVATS for thymoma in comparison with that of intercostal video-assisted thoracoscopic surgery (IVATS) thymectomy.

Methods

All the relevant data systematically analyzed in this thesis were retrieved from PubMed, the Cochrane Library, web of science, EMBASE, and ClinicalTrials.gov. The time span for data retrieval was from the date of database establishment to March 2022. The outcome indicators include operation time, intraoperative blood loss, duration of postoperative drainage, postoperative hospital days, visual analogue scale (VAS) score on the day of operation, VAS score on postoperative day 3, and VAS score on postoperative day 7; postoperative complications were analyzed in our meta-analysis.

Results

In 13 studies of this paper, there were 1,198 cases included. Among them, 563 cases were treated by SVATS thymectomy and 635 cases by IVATS thymectomy. There was no significant difference in the operation time [113.38 vs. 119.91  min, 95% confidence interval (CI): −0.70–0.15, p = 0.20) and the incidence of intraoperative and postoperative complications (RR = 0.82, 95% CI: 0.58–1.15, p = 0.25) between SVATS thymectomy and IVATS thymectomy. However, SVATS thymectomy significantly reduced the amount of intraoperative blood loss (47.68 vs. 66.69  mL, SMD = −0.57, 95% CI: −0.95 to −0.18, p = 0.004), postoperative drainage days (2.12 vs. 2.72 days, SMD = −0.46, 95% CI: −0.74 to −0.18, p = 0.001), postoperative hospital stays (4.53 vs. 5.91 days, SMD = −0.64, 95% CI: −0.96 to −0.31, p = 0.0001), and VAS scores after the operation.

Discussion

SVATS thymectomy is safe and feasible, and the perioperative effect is better than IVATS thymectomy to a certain extent, which is worthy of popularization and further research.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/

An Overview of Surgical Treatment of Thymic Epithelial Tumors in Korea: A Retrospective Multicenter Analysis

Background

Thymic epithelial tumors (TETs) are rare, and information regarding their surgical outcomes and prognostic factors has rapidly changed in the past few decades. We analyzed surgical treatment practices for TETs and outcomes in terms of overall survival (OS) and freedom from recurrence (FFR) during a 13-year period in Korea.

Methods

In total, 1,298 patients with surgically resected TETs between 2000 and 2013 were enrolled retrospectively. OS and FFR were calculated using the Kaplan-Meier method and evaluated with the log-rank test. Prognostic factors for OS and FFR were analyzed with multivariable Cox regression.

Results

A total of 1,098 patients were diagnosed with thymoma, and 200 patients were diagnosed with thymic carcinoma. Over the study period, the total number of patients with surgically treated TETs and the proportion of patients who underwent minimally invasive thymic surgery (MITS) increased annually. The 5-year and 10-year survival rates of surgically treated TETs were 91.0% and 82.1%, respectively. The 5-year and 10-year recurrence rates were 86.3% and 80.0%, respectively. The outcomes of surgically treated TETs improved over time. Multivariable Cox hazards analysis for OS, age, tumor size, and Masaoka-Koga stage were independent predictors of prognosis. The World Health Organization classification and tumor-node-metastasis (TNM) staging were also related to the prognosis of TETs.

Conclusion

Surgical treatment of TETs achieved a good prognosis with a recent increase in MITS. The M-K stage was the most important prognostic factor for OS and FFR. The new TNM stage could also be an effective predictor of the outcomes of TETs.

SEOM-GECP-GETTHI Clinical Guidelines for the treatment of patients with thymic epithelial tumours (2021)

Thymic epithelial tumours (TET) represent a heterogeneous group of rare malignancies that include thymomas and thymic carcinoma. Treatment of TET is based on the resectability of the tumour. If this is considered achievable upfront, surgical resection is the cornerstone of treatment. Platinum-based chemotherapy is the standard regimen for advanced TET. Due to the rarity of this disease, treatment decisions should be discussed in specific multidisciplinary tumour boards, and there are few prospective clinical studies with new strategies. However, several pathways involved in TET have been explored as potential targets for new therapies in previously treated patients, such as multi-tyrosine kinase inhibitors with antiangiogenic properties and immune checkpoint inhibitors (ICI). One third of patient with thymoma present an autoimmune disorders, increasing the risk of immune-related adverse events and autoimmune flares under ICIs. In these guidelines, we summarize the current evidence for the therapeutic approach in patients with TET and define levels of evidence for these decisions.

Combined clinical and specific positron emission tomography/computed tomography-based radiomic features and machine-learning model in prediction of thymoma risk groups

OBJECTIVES

In this single-center study, we aimed to propose a machine-learning model and assess its ability with clinical data to classify low- and high-risk thymoma on fluorine-18 (18F) fluorodeoxyglucose (FDG) (18F-FDG) PET/computed tomography (CT) images.

METHODS

Twenty-seven patients (14 male, 13 female; mean age: 49.6 ± 10.2 years) who underwent PET/CT to evaluate the suspected anterior mediastinal mass and histopathologically diagnosed with thymoma were included. On 18F-FDG PET/CT images, the anterior mediastinal tumor was segmented. Standardized uptake value (SUV)max, SUVmean, SUVpeak, MTV and total lesion glycolysis of primary mediastinal lesions were calculated. For texture analysis first, second, and higher-order texture features were calculated. Clinical information includes gender, age, myasthenia gravis status; serum levels of lactate dehydrogenase (LDH), alkaline phosphatase, C-reactive protein, hemoglobin, white blood cell, lymphocyte and platelet counts were included in the analysis.

RESULTS

Histopathologic examination was consistent with low risk and high-risk thymoma in 15 cases and 12 cases, respectively. The age and myasthenic syndrome were statistically significant in both groups (P = 0.039 and P = 0.05, respectively). The serum LDH level was also statistically significant in both groups (450.86 ± 487.07 vs. 204.82 ± 59.04; P < 0.001). The highest AUC has been achieved with MLP Classifier (ANN) machine learning method, with a range of 0.830 then the other learning classifiers. Three features were identified to differentiate low- and high-risk thymoma for the machine learning, namely; myasthenia gravis, LDH, SHAPE_Sphericity [only for 3D ROI (nz>1)].

CONCLUSIONS

This small dataset study has proposed a machine-learning model by MLP Classifier (ANN) analysis on 18F-FDG PET/CT images, which can predict low risk and high-risk thymoma. This study also demonstrated that the combination of clinical data and specific PET/CT-based radiomic features with image variables can predict thymoma risk groups. However, these results should be supported by studies with larger dataset.

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.

A novel method of subxiphoid video-assisted thoracic surgery for thymectomy

Background

With advances in thoracoscopic surgical instruments and techniques, subxiphoid video-assisted thoracic surgery (S-VATS) has become the main approach for anterior mediastinal tumor resection under thoracoscopy. However, the drawbacks of S-VATS, including it being a relatively unfixed surgical procedure, make it complicated and difficult for unexperienced surgeons to master.

Methods

This study retrospectively reviewed and analyzed consecutive patients with anterior mediastinal tumor or myasthenia gravis (MG) who underwent S-VATS at the Fujian Medical University Union Hospital, China, between March 2015 and April 2019.Patients were divided into the conventional group and the “four-zone one-way” group. Intraoperative and postoperative variables were compared between the groups. Cumulative sum (CUSUM) analysis was applied to determine the operation time (OT)-learning curve of the S-VATS “four-zone one-way” method.

Results

A total of 82 patients were included in this analysis, of which, 40 patients underwent the conventional method of S-VATS and 42 patients underwent the “four-zone one-way” method. Patients in the “four-zone one-way” group had significantly shorter OT (138.50±29.43 and 118.00±28.18 minutes, respectively; P=0.002) and significantly less blood loss (36.00±20.16 and 23.92±14.96 mL, respectively; P=0.003) compared with patients in the conventional group. Our data indicated that there was no difference of the efficacy of MG treatment between the 2 groups. The difference in the preoperative and postoperative quantitative MG scoring system score (QMG-score) and the dose reduction of cholinesterase inhibitors was comparable between patients in the 2 groups. According to the CUSUM analysis curve, after a steady improvement over phase I (cases 1–12 for the traditional method and cases 1–5 for the “four-zone one-way” method), the surgical procedure could be mastered. Phase III occurred after case 26 in the traditional group and case 28 in the “four-zone one-way” group, and is characterized by rapid improvements.

Conclusions

Compared with the conventional method of S-VATS, the “four-zone one-way” method significantly decreased OT and estimated blood loss. These results demonstrated the feasibility and safety of the “four-zone one-way” method of S-VATS.

[Comparative analysis of thoracoscopic and open thymectomy for thymoma stage I-II]

OBJECTIVE

To improve the short-term postoperative outcomes in patients with thymoma stage I-II by using of thoracoscopic thymectomy (VATS TE) and to compare this technique with open (OTE) thymectomy.

MATERIAL AND METHODS

A retrospective analysis included 98 patients who had undergone surgery for thymoma stage I and II for the period from January 2001 to December 2019. VATS TE (main group) was performed in 53 (54.1%) cases, OTE (control group) - in 45 (45.9%) patients.

RESULTS

Duration of VATS TE and OTE was similar. VATS procedure was characterized by less intraoperative blood loss (50 vs 225 ml, p=0.000), lower pain scores and morphine consumption (p=0.000), shorter postoperative pleural drainage (1.5 vs 3.8 days, p=0.000), and postoperative hospital-stay (7.6 vs 12.7 days, p=0.000). Incidence of major complications was significantly less in the main group (9.4% vs. 1.9%, p=0.001).

CONCLUSION

VATS TE is effective and safe procedure for thymoma stage I-II. Postoperative period after VATS TE is characterized by less intraoperative blood loss, incidence of complications, duration of pleural drainage and hospital-stay.

Limited resection for early-stage thymoma: minimally invasive resection does not mean limited resection

Standard resection for patients with thymoma is resection of thymoma with total thymectomy (TTx) via median sternotomy. Hence, limited resection for thymoma means a lesser extent of resection of normal thymus compared with a standard procedure, i.e. resection of thymoma with partial thymectomy (PTx). In contrast, minimally invasive resection has been defined as resection of thymoma with TTx via a less-invasive approach. However, to date, few studies have precisely evaluated the differences in surgical and oncological outcomes among these three procedures. This report summarizes the differences among these three procedures with a review of studies (January 2000 to December 2020) focusing on the difference in surgical and oncological outcomes and presents current issues in the surgical management of thymoma. In this report, 16 studies were identified; 5 compared standard resection to limited resection, 9 compared standard resection to minimally invasive resection and 2 compared limited resection to minimally invasive resection. Most studies reported that the surgical and oncological outcomes of limited resection or minimally invasive resection were similar to those of standard resection in patients with early-stage thymoma. However, they did not include a sufficient follow-up period. Both limited resection and minimally invasive resection for early-stage thymoma might be reasonable treatment options. However, they are still promising modes of resection. Further studies with a long follow-up period are needed.

Comparison of Early Postoperative Outcomes of Patients Undergoing Robot-Assisted and Transsternal Thymectomy

Objective: Robot-assisted thoracoscopic surgery (RATS) is a minimally invasive technique that has been used in thymectomy operations in recent years. Minimally invasive surgical techniques offer less postoperative pain, a shorter length of hospital stay, and faster recovery compared to conventional surgical techniques. In our study, we aimed to compare the outcomes of robotic and transsternal thymectomies by analyzing the operative and postoperative data of these two approaches. Methods: Twelve robotic thymectomy patients and 16 transsternal thymectomy patients who were operated on in our clinic in 2018 were included in the study. Results: There was no significant difference between the two groups in terms of operative time (p=0.231). The median chest tube duration was 1.5 [range, 1-2] days in robotic thymectomy and 2.5 [range, 1-3.75] days in transsternal thymectomy. However, there was no statistically significant difference between the two groups (p=0.082). The amount of chest tube drainage was significantly lower in the robotic thymectomy group (p=0.006). The length of hospital stay was also significantly shorter in robotic thymectomy patients (p<0.001). Conclusion: The amount of chest tube drainage was lower and the length of hospital stay was shorter in the robotic surgery compared to the transsternal approach. There was no significant difference between the two techniques in terms of operative time. Within today's minimally invasive surgical techniques, robotic thymectomy can be considered a practical, comfortable, and safe technique with better early postoperative outcomes. Keywords: Robot-Assisted Thymectomy, Thymectomy, Transsternal Thymectomy

The robotic thymectomy via the subxiphoid approach: technique and early outcomes

OBJECTIVES

Robotic thymectomy via the subxiphoid approach (RTX) is a recently introduced surgical approach. This study aimed to report on the surgical technique and early outcomes of RTX in our institute.

METHODS

RTX was performed using the 3-arm technique in the da Vinci robotic surgical system. The camera was inserted into a subxiphoid port, and 2 robotic arms were inserted in bilateral intercostal ports. A complete dissection of both cervical poles up to the thyroid gland was conducted, and bilateral phrenic nerves were identified in all cases. Radical combined resection of adjacent organs, including the lung, pericardium, phrenic nerve and the innominate vein, was performed if necessary. The resected specimen could be retrieved through the subxiphoid port site.

RESULTS

A total of 110 patients underwent RTX in our institute from October 2016 to August 2019. Thymoma was the most common diagnosis (60.9%), and the mean size of the tumours was 4.9 ± 2.4 cm. Combined resection was performed in the lung (n = 9, 8.1%), pericardium (n = 6, 5.5%) and innominate vein (n = 5, 4.5%). There were 2 minor postoperative complications (1.8%), and the mean length of hospital stay was 2.2 ± 1.4 days. For the cumulative sum curve analysis of the learning curve using operative time, 50 cases were necessary to gain proficiency.

CONCLUSIONS

RTX was a safe and feasible surgical approach, even in advanced thymic epithelial tumours. It should be considered one of the valuable surgical options in minimally invasive thymectomy.

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.