Subxiphoid single-port thymectomy without CO2 insufflation: Experience of a single center

BACKGROUND

The subxiphoid single-port approach for thymectomy has advantages compared with conventional lateral transthoracic approaches. Most of centers use CO₂ insufflation to secure an appropriate surgical field during subxiphoid thymectomy, which causes fighting between surgical instruments and restrictions on the types of surgical instruments. The objective of this study is to introduce an effective method to establish the subxiphoid approach without CO₂ insufflation using a retractor and steel wire.

METHODS

All consecutive 59 patients undergoing subxiphoid single-port thymectomy between August 2014 and August 2021 were reviewed retrospectively.

RESULTS

We analyzed data of 59 patients (31 male and 28 female) with a median age of 59 years (range 50-68). Two (3.4%) patients presented postoperative complications. The conversion to a different approach was required in 4 (6.8%) cases. The median follow-up time was 23 months (range 10-41) and loco-regional recurrence was observed in one patient (1.7%). There were no intraoperative deaths and the postoperative mortality. No complications related to sternal wiring occurred.

CONCLUSIONS

Subxiphoid single-port thymectomy without CO₂ using a retractor and steel wire insufflation is a technically feasible method.

Robotic subxiphoid thymectomy versus lateral thymectomy: A propensity-score-matched comparison

OBJECTIVES

This study aims to compare the surgical outcomes between conventional robotic lateral thymectomy and recently introduced robotic subxiphoid thymectomy for the surgical treatment of anterior mediastinal tumors.

METHODS

Between May 2008 and July 2020, the patients who underwent robotic thymectomy were included in the study. Because robotic subxiphoid thymectomy were more frequently performed in the tumors with advanced stages and located in the upper mediastinum abutting the brachiocephalic vein, we conducted propensity score matching to minimize selection bias.

RESULTS

A total of 389 patients (subxiphoid and lateral thymectomy in 188 and 200 patients, respectively) underwent robotic thymectomy, and 141 matched pairs in each group were included in the analysis. After the matching process, both methods showed comparable demographic features, pathological diagnoses, and pathologic stages. Robotic subxiphoid thymectomy was performed more frequently for mediastinal masses abutting the brachiocephalic vein (p < 0.01). The proportion of simultaneous resection of adjacent structures, including the lung, pericardium, and phrenic nerve, was similar between the two groups; however, the proportion of brachiocephalic vein resection was significantly higher in the robotic subxiphoid thymectomy (p < 0.01). Although both groups showed comparable complication rates (p = 0.80), robotic subxiphoid thymectomy was associated with shorter hospital stays (2.4 (2.4) vs 3.1 (2.4) days; p = 0.03) and a lower pain score in the immediate and early postoperative periods.

CONCLUSIONS

Robotic subxiphoid thymectomy could be performed safely in complex upper mediastinal tumors abutting the brachiocephalic vein and showed better early outcomes with shorter hospital stays and lesser postoperative pain than robotic lateral thymectomy.

Morvan Syndrome Converted from Isaacs' Syndrome after Thymectomy with Positivity for Both Anti-LGI1 and Anti-CASPR2 Antibodies

Anti-voltage-gated potassium channel complex antibodies-mediated disorder includes Isaacs' syndrome, which is characterized by neuromyotonia, and Morvan syndrome, which is characterized by neuromyotonia, encephalopathy and autonomic dysfunction. We herein report a patient with Morvan syndrome that converted from Isaacs' syndrome after thymectomy. The patient first presented with myospasm in all extremities and positivity for both anti-leucine-rich glioma inactivated 1 (LGI1) and anti-contactin-associated protein like 2 (CASPR2) antibodies and subsequently developed encephalopathy after thymectomy, which was successfully improved by immunotherapy. This is the first case of Morvan syndrome wherein thymectomy worsened Isaacs' syndrome, suggesting that immunotherapy should be considered for Isaacs' syndrome accompanied by positivity for both anti-LGI1 and anti-CASPR2 antibodies to prevent worsening to Morvan syndrome.

Rippling Muscle Disease with Irregular Toe Jerks and Anti-acetylcholine Receptor Antibodies: Remission after Extended Thymectomy

We herein report a 63-year-old rippling muscle disease (RMD) patient who presented with painless stiffness, muscle hypertrophy and muscle contractions elicited by mechanical stimulation. He also showed irregular toe jerks and a slightly elevated level of anti-acetylcholine receptor antibody (AChR-Ab). Since he had a mediastinal mass mimicking thymoma, which was later revealed to be a bronchial cyst, he underwent extended thymectomy. The irregular toe jerks disappeared within a week after the operation. The other muscle symptoms completely remitted 27 months after the onset. This is the first report of a sporadic case of RMD with irregular toe jerks that resolved after extended thymectomy.

Short-term and sustained clinical response following thymectomy in patients with myasthenia gravis

OBJECTIVE

To investigate short- and long-term outcome following thymectomy in patients with acetylcholine-receptor-antibody (AchR-Ab) positive myasthenia gravis (MG).

METHODS

Rates of clinical response (defined as minimal manifestation, pharmacological or complete stable remission) lasting for at least one year were retrospectively analyzed using Cox proportional hazard models. The occurrence of relapses was recorded during follow-up. Clinical factors associated with achieving an initial or a sustained response were analyzed.

RESULTS

94 patients with a median age of 33 years (IQR 22-51), 68% with non-thymomatous MG and 32% with thymoma-associated MG were included. An initial clinical response was reached in 72% (68/94). Neither sex, age at onset, thymus histology, delay to surgery after disease onset, surgical approach, corticosteroid treatment nor clinical severity before thymectomy were significantly associated with achieving this endpoint. During long-term follow-up (median 89.5 months; IQR 46-189.5) only half of the patients with an initial response (34/68) had a sustained response without relapses. No clinical factors predicted if the response would become sustained. In patients without immunosuppressive treatment before thymectomy (n=24), a high AChR-Ab levels reduction rate after thymectomy was associated with a higher likelihood of achieving an initial response (p=0.03).

CONCLUSION

Sustained long-term clinical response of MG patients after thymectomy is significantly lower than the initial response rates would suggest. The observation that none of the evaluated clinical factors was associated with a worse outcome supports the current clinical practice of patient selection for thymectomy. The relative decline of AchR-antibodies after surgery appears to be a promising prognostic marker.

Maximal Thymectomy via Mini Sternotomy with Pleural Preservation

Gaurav PatelBackground  There are different surgical techniques used for maximal thymectomy. Each technique has its own advantages and disadvantages. We propose a mini sternotomy with pleural preservation approach for complete maximal thymectomy. Methods  Over time range of 5 years, 32 patients with diagnosis of thymoma with or without myasthenia gravis (MG) underwent maximal thymectomy by mini sternotomy in our institute. Patient records were examined for the following parameters: age, sex, preoperative medication, symptoms of MG as per Myasthenia Gravis Foundation of America grading system, operating time, duration of postoperative ventilation, length of stay in the intensive care unit, overall length of hospitalization, and postoperative complications. Results  The mean age of patients in our study was 43.66. Sex ratio in this study was almost equal. Sixty-nine percent of patients were stage I thymoma according to Masaoka staging. Size of the tumor ranged from 3 to 8 cm with mean size being 4.54 cm. Complete resection with negative tumor margins was possible in all the cases. Four patients had intraoperative pleural injury out of which two patients required intercostal tube insertion. We did not have any serious postoperative complications with no perioperative mortality. Conclusions  Mini sternotomy allows maximal removal of thymus through a less invasive approach and is associated with a significantly smoother postoperative course, less overall complications, and good clinical outcome. It is a simple technique that can be performed by any thoracic and surgical oncologists especially in Indian subcontinent where facilities of video-assisted thoracoscopic surgery and robotic video-assisted thoracoscopic surgery are not available in all areas and are expensive.

Childhood-Onset Myasthenia Gravis Patients Benefited from Thymectomy in a Long-Term Follow-up Observation

INTRODUCTION

 The effect of thymectomy on the treatment of childhood-onset myasthenia gravis (CMG) remains debatable. The objective of this study was to evaluate the clinical outcome and relevant prognostic factors of thymectomy for CMG patients.

MATERIALS AND METHODS

 A total of 32 CMG patients who underwent thymectomy before 18 years of age were included in this retrospective study. Clinical state following thymectomy was assessed by quantified myasthenia gravis (QMG) scores, myasthenia gravis-related activities of daily living (MG-ADL) scores, and Myasthenia Gravis Foundation of America postintervention status. Repeated-measures analysis of variance (ANOVA) examined the changes in postoperative scores during the 5-year follow-up. Univariate logistic regression was applied to identify factors associated with short-term (1-year postoperation) and long-term (5-year postoperation) clinical outcomes.

RESULTS

 Repeated-measures ANOVA showed that QMG scores (F = 6.737, p < 0.001) and MG-ADL scores (F = 7.923, p < 0.001) decreased gradually with time. Preoperative duration (odds ratio [OR] = 0.85, 95% confidence interval [CI]: 0.73-1.00, p = 0.043), gender (OR = 0.19, 95% CI: 0.04-0.94, p = 0.041), and MG subgroup (OR = 13.33, 95% CI: 1.43-123.99, p = 0.023) were predictors for 1-year postoperative prognosis. Shorter disease duration (OR = 0.82, 95% CI: 0.70-0.97, p = 0.018) and generalized CMG (OR = 6.11, 95% CI: 1.06-35.35, p = 0.043) were found to have more favorable long-term results.

CONCLUSION

 Our results suggest that thymectomy is effective in treating CMG. Thymectomy could be recommended for CMG patients, especially for patients in the early course of GMG.

CT Radiomic Features for Predicting Resectability and TNM Staging in Thymic Epithelial Tumors

BACKGROUND

To explore the performance of a computed tomography based radiomics model in the preoperative prediction of resectability status and TNM staging in thymic epithelial tumors.

METHODS

We reviewed the last preoperative computed tomography scan of patients with thymic epithelial tumors prior to resection and pathology evaluation at our institution between February 2008 and June 2019. A total of 101 quantitative features were extracted and a radiomics model was trained using elastic net penalized logistic regressions for each aim. In the set-aside testing sets, discriminating performance of each model was assessed with area under receiver operating characteristic curve.

RESULTS

Our final population consisted of 243 patients with: 153 (87%) thymomas, 23 (9%) thymic carcinomas, and 9 (4%) thymic carcinoids. Incomplete resections (R1 or R2) occurred in 38 (16%) patients, and 67 (28%) patients had more advanced stage tumors (stage III or IV). In the set-aside testing sets, the radiomics model achieved good performance in preoperatively predicting incomplete resections (area under receiver operating characteristic curve: 0.80) and advanced stage tumors (area under receiver operating characteristic curve: 0.70).

CONCLUSIONS

Our computed tomography radiomics model achieved good performance to predict resectability status and staging in thymic epithelial tumors, suggesting a potential value for the evaluation of radiomic features in the preoperative prediction of surgical outcomes in thymic malignancies.

In vivo availability of the cytokine IL-7 constrains the survival and homeostasis of peripheral iNKT cells

Understanding the homeostatic mechanism of invariant natural killer T (iNKT) cells is a critical issue in iNKT cell biology. Because interleukin (IL)-15 is required for the thymic generation of iNKT cells, IL-15 has also been considered necessary for the homeostasis of peripheral iNKT cells. Here, we delineated the in vivo cytokine requirement for iNKT cells, and we came to the surprising conclusion that IL-7, not IL-15, is the homeostatic cytokine for iNKT cells. Employing a series of experimental mouse models where the availability of IL-7 or IL-15 was manipulated in peripheral tissues, either by genetic tools or by adult thymectomy and cytokine pump installation, we demonstrate that the abundance of IL-7, and not IL-15, limits the size of the peripheral iNKT cell pool. These results redefine the cytokine requirement for iNKT cells and indicate competition for IL-7 between iNKT and conventional αβ T cells.

Thymectomy for myasthenia gravis: A pathological analysis

BACKGROUND

Myasthenia gravis (MG) is a prototypic T-cell-dependent antibody-mediated autoimmune disease that leads to ocular or generalized muscular weakness. The disease is most commonly caused by antibodies to the acetylcholine receptors, often with underlying thymic pathology.

AIMS

This study is aimed at analyzing the pathological spectrum of the excised thymuses in patients with myasthenia.

MATERIALS AND METHODS

This was a retrospective 10-year study of 68 thymectomy specimens performed as a part of the treatment of patients with MG.

STATISTICAL ANALYSIS

Nil.

RESULTS

There were 47 males and 21 females (male to female ratio of 2.2:1) with a mean age of 41 years. Only three patients presented with ocular myasthenia. The thymus was normal in 9 patients (13.2%) and atrophic in 17 patients (25%). Follicular hyperplasia and thymomas were seen in 6 and 36 patients, respectively.

CONCLUSION

The thymectomies performed in patients of MG had a fairly variable spectrum on histology; the thymic tumors were predominantly of the cortical phenotype.

Early Flare-Ups of Myasthenia Gravis After Thoracoscopic Thymectomy in a Patient Recently Receiving BNT162b2 mRNA COVID-19 Vaccination

Myasthenia gravis (MG) is an autoimmune disorder characterized by abnormal neuromuscular transmission. The thymus is believed to play a key role in the pathogenesis of MG, and thymectomy has been an optional treatment for the disease. Relapse of MG after thymectomy has been reported. Exacerbations and new onset of MG following COVID-19 vaccination have also been documented. This report presents a case of a stable MG patient with recent COVID-19 vaccination experiencing flare-ups of symptoms shortly after video-assisted thoracoscopic (VATS) thymectomy. A 31-year-old female received the second dose of the BNT162b2 mRNA COVID-19 vaccine eight days before thymectomy and developed flare-ups of symptoms four days after the surgery. Although the substantial link between MG exacerbations post-thymectomy and pre-thymectomy COVID-19 vaccination cannot be concluded, this observation warrants further research.

Early Thymectomy Is Associated With Long-Term Impairment of the Immune System: A Systematic Review

Background and Aims

Congenital heart diseases (CHDs) are diagnosed in approximately 9 in 1,000 newborns, and early cardiac corrective surgery often requires partial or complete thymectomy. As the long-term effect of early thymectomy on the subsequent development of the immune system in humans has not been completely elucidated, the present study aimed to evaluate the effects of thymus removal on the functional capacity of the immune system after different periods.

Methods

A systematic review of the literature was performed using MEDLINE, EMBASE, LILACS and Scopus. The inclusion criteria were original studies that analyzed any component of the immune system in patients with CHD who had undergone thymectomy during cardiac surgery in the first years of life. The results were evaluated for the quality of evidence.

Results

Twenty-three studies were selected and showed that patients who underwent a thymectomy in the first years of life tended to exhibit important alterations in the T cell compartment, such as fewer total T cells, CD4+, CD8+, naïve and CD31+ T cells, lower TRECs, decreased diversity of the TCR repertoire and higher peripheral proliferation (increased Ki-67 expression) than controls. However, the numbers of memory T cells and Treg cells differed across the selected studies.

Conclusions

Early thymectomy, either partial or complete, may be associated with a reduction in many T cell subpopulations and TCR diversity, and these alterations may persist during long-term follow-up. Alternative solutions should be studied, either in the operative technique with partial preservation of the thymus or through the autograft of fragments of the gland.

Systematic Review Registration

Prospero [157188].

Complications of robot-assisted thymectomy: A single-arm meta-analysis and systematic review

BACKGROUND

Recently, thymectomy using minimally invasive approaches has been increasing with the development of robotic video-assisted thoracoscopic surgery (R-VATS). Although multimodal approach is effective for robot assisted thymectomy, it is necessary to determine the approach (left, right or subxiphoid) associated with the least complications.

METHODS

An electronic retrieval from PubMed, Embase, Web of Science, GreyNet International and The Cochrane Library. The single-arm meta-analysis was performed to compare the rate of complications of right- and left-side approaches by R-VATS.

RESULTS

A total of 21 studies including 930 patients were identified. The pooled incidence of total complications was 12.2% (confidence interval: 10.0%-14.8%) for all studies. The overall complication rate was 17.3% for the right-side compared with 7.4% for the left side (P < 0.001, odds ratio = 2.484, 1.601-3.852). The pooled incidence of air leak was significantly higher for the right versus left side (5.1% vs. 1.2%, respectively; p = 0.004). The incidence of atrial fibrillation was higher for the right-side compared with the left-side approach (4% vs. 1.2%, respectively; p = 0.004). The open conversion rate was significantly higher for the right versus the left-side (6.5% vs. 2.9%, respectively; p = 0.004). However, there was no significant difference in the pooled incidence of pleural effusion and thoracic duct fistula when comparing the right- and left-side approaches. In subgroup analysis, in the left approach, the incidence of overall complications (28.6% vs. 5.5%, respectively; p = 0.002) and pleural effusion (14.3% vs. 1%, respectively; p = 0.002) was higher for the 'Old Age' group compared with the 'Youth' group; However, In the subgroup analysis of gender, there was no significant difference in the incidence of complications after thymectomy.

CONCLUSION

Robotic video-assisted thoracoscopic surgery can be performed on the left- and right-sides; however, complications are minimal with the left-side approach. These data demonstrate that the incidence of overall complications, atrial fibrillation, open conversion ratios, and air leak rate of left-side R-VATS thymectomy are lower than those of right-side. Further subgroup analysis showed that the incidence of postoperative complications was higher in the older group.

Robotic thymectomy for myasthenia gravis surgical techniques and outcomes

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

Robotic vs. Transsternal Thymectomy: A Single Center Experience over 10 Years

Introduction: Thymomas are the most common tumors of the mediastinum. Traditionally, thymectomies have been performed through a transsternal (TS) approach. With the development of robot-assisted thoracic surgery (RATS), a promising, minimally invasive, alternative surgical technique for performing a thymectomy has been developed. In the current paper, the oncological and surgical outcomes of the TS vs. RATS thymectomies are discussed. Methods: For the RATS thymectomy, two 8 mm working ports and one 12 mm camera port were used. In the transsternal approach, we performed a median sternotomy and resected the thymic tissue completely, in some cases en bloc with part of the lung and/or, more frequently, a partial pericardiectomy with consequent reconstruction using a bovine pericardial patch. The decisions for using the TS vs. RATS methods were mainly based on the suspected tumor invasion of the surrounding structures on the preoperative CT scan and tumor size. Results: Between January 2010 and November 2020, 149 patients were submitted for an anterior mediastinal tumor resection at our institution. A total of 104 patients met the inclusion criteria. One procedure was performed through a hemi-clamshell incision. A total of 81 (78%) patients underwent RATS procedures, and 22 (21.1%) patients were treated using a transsternal (TS) tumor resection. Thymoma was diagnosed in 53 (51%) cases. In the RATS group, the median LOS was 3.2 ± 2.8 days and the median tumor size was 4.4 ± 2.37 cm compared to the TS group, which had a median LOS of 9 ± 7.3 days and a median tumor size of 10.4 ± 5.3 cm. Both differences were statistically significant (p < 0.001). Complete resection was achieved in all patients. Conclusion: While larger and infiltrating tumors (i.e., thymic carcinomas) were usually resected via a sternotomy, the RATS procedure is a good alternative for the resection of thymomas of up to 9.5 cm, and the thymectomy is a strong approach for myasthenia gravis. The oncological outcomes and survival rates were not influenced by the chosen approach.

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.

Massive true thymic hyperplasia in a 3-month-old infant: case report and literature review

BACKGROUND

True thymic hyperplasia (TTH) is characterized as a distinct increase in both size and weight of thymus, which retains normal microscopic and immunohistochemical appearances. Massive true thymic hyperplasia (MTTH) is an extremely rare but significant subtype of TTH in pediatric ages due to its potentially serious consequences. It was reported that the age of cases with MTTH was predominantly between 1 and 15 years, while those before 1 year rarely occurred. By presenting the diagnosis and treatment process of our case as well as reviewing the related literature, we aimed to analyze the clinical characteristics of MTTH for patients younger than 1 year.

CASE

A 3-month-old male infant was admitted to our department with a chief complaint of gradually increasing polypnea over 9 days, whose preoperative imaging examination showed a large intrathoracic soft tissue shadow predominantly on the right side. The percutaneous fine-needle biopsy guided by ultrasonography was performed to identify its diagnosis. However, proliferating lymphocytes and Hassall`s corpuscles were seen microscopically in the biopsy tissues, which were immunohistochemically positive for CD3, CD19, CD20, CD99, TdT, PCK and Ki67 ( > 90%). Due to the aggravating symptoms, a second operation with total thymectomy was carried out successfully for this infant, which confirmed the diagnosis of TTH again by both morphological study and immunohistochemical staining from the surgical specimen.

CONCLUSIONS

By reviewing the literature, there were only 10 cases with MTTH reported between 1975 and 2020 for children aged < 1 year of life, together with our present one. In MTTH patient`s sex had an obviously male predominance (70%). Nine out of 10 presented initial symptoms or signs related to respiratory system and 6 patients showed respiratory distress. All patients were successfully treated by surgical thymectomy without any postoperative complications. The prognosis of MTTH was very successful.

Subxiphoid single-port thymectomy: six-year experience of a single center

BACKGROUND

The subxiphoid single-port approach for thymectomy has several advantages compared with conventional lateral transthoracic approaches. However, perioperative outcomes of subxiphoid single-port thymectomy are still lacking. The objective of this study is to present our 6-year experience of subxiphoid single-port thymectomy, including our learning curve.

METHODS

All consecutive 49 patients undergoing subxiphoid single-port thymectomy between August 2014 and September 2020 were reviewed retrospectively.

RESULTS

We analyzed data of 49 patients (27 males and 22 females) with a median age of 58 years (range 49-68). Two patients presented postoperative complications. The conversion to a different approach was required in four cases. The median follow-up time was 17 months (range 3-35) and locoregional recurrence was observed in one patient. There were no intraoperative deaths and postoperative mortality. The operation time cumulative summation learning curve analysis revealed that the curves descended from the 24th case.

CONCLUSIONS

The subxiphoid single-port approach for thymectomy is a safe and feasible modality with few complications.

[Long-term outcomes of thoracoscopic thymectomy for thymoma stage i-ii]

OBJECTIVE

To compare long-term outcomes of video-assisted thoracoscopic (VATS) and conventional open surgery in patients with early-stage (Masaoka stage I-II) thymic malignancies.

MATERIAL AND METHODS. A

Retrospective study included patients after VATS and open thymectomy for the period 2000-2019. Long-term outcomes were analyzed.

RESULTS

VATS thymectomy was performed in 53 (54.1%) patients, open thymectomy - in 45 (45.9%) cases. Median follow-up period was 66.9 months. Overall 5-year survival was 89.8% and 97% in the Open and VATS groups, respectively (p=0.076). Disease-free survival rates were 79.6% and 86.6% (p=0.279), respectively. There was no significant difference in cumulative incidence of recurrence (13.3% vs 7.5%, p=0.505). Age <50 years and tumor size >5 cm were the independent risk factors of recurrence.

CONCLUSION

VATS thymectomy is an effective approach ensuring similar long-term outcomes in patients with early stages of thymic malignancies.

T cell phenotype in paediatric heart transplant recipients

Paediatric heart transplantation recipients suffer an increased incidence of infectious, autoimmune and allergic problems. The relative roles of thymus excision and immunosuppressive treatments in contributing to these sequelae are not clear. We compared the immunological phenotypes of 25 heart transplant recipients (Tx), 10 children who underwent thymus excision during non-transplantation cardiac surgery (TE) and 25 age range-matched controls, in two age bands: 1-9 and 10-16 years. Significant differences from controls were seen mainly in the younger age band with Tx showing lower CD3 and CD4 cell counts whilst TE showed lower CD8 cell counts. Naïve T cell and recent thymic emigrant proportions and counts were significantly lower than controls in both groups in the lower age band. T cell recombination excision circle (TREC) levels were lower than controls in both groups in both age bands. There were no differences in regulatory T cells, but in those undergoing thymus excision in infancy, their proportions were higher in TE than Tx, a possible direct effect of immunosuppression. T cell receptor V beta spectratyping showed fewer peaks in both groups than in controls (predominantly in the older age band). Thymus excision in infancy was associated with lower CD8 cell counts and higher proportions of Tregs in TE compared to Tx. These data are consistent with thymus excision, particularly in infancy, being the most important influence on immunological phenotype after heart transplantation.

[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.

Determinants of Suboptimal Outcome Following Thymectomy in Myasthenia Gravis

Background

Response to thymectomy in myasthenia gravis (MG) is influenced by various patient-, disease-, and therapy-related factors.

Methods

Retrospective analysis of 128 patients with MG who underwent maximal thymectomy over 15 years was done to identify the determinants of suboptimal clinical outcome.

Results

Among the 128 patients, 62 (48.4%) were females with a mean age of 38.97 (12.29) years. Thymomatous MG occurred in 66 (51.6%). Overall improvement from preoperative status was noted in 88 (68.8%) patients after mean follow-up of 51.68 (33.21) months. The presence of thymoma was the major predictor of suboptimal clinical outcome (P = 0.001), whereas age, gender, preoperative disease severity, and seropositive status did not attain significance. Patients with better outcome had received higher steroid dose preoperatively (P = 0.035).

Conclusions

Suboptimal response after thymectomy occurred in one-third of MG patients, more commonly with thymomatous MG. Relationship of preoperative steroid therapy to remission merits evaluation.

Association Between Myasthenia Gravis and Systemic Lupus Erythematosus as a Comorbid State

Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune states which have presentational similitude. Both conditions test serologically positive for anti-nuclear antibodies and require exceptional differential diagnostic acumen to segregate one from the other. The hypothesized factors provoking these diseases may be immunological, genetic, hormonal, or environmental and can be better understood by large-scale controlled epidemiological studies. Biochemical factors such as variation in CXC (an α chemokine subfamily), CXCL13, and granulocyte-macrophage colony-stimulating factor levels are assumed to play a pivotal role in the pathogenesis of SLE and MG; however, further studies are required to understand their exact mechanism and effect on the underlying autoimmune diseases. Following this, another precipitating factor for this overlap is believed to be thymectomy which is performed to eliminate MG symptoms. Although thymectomy is the effective treatment modality in MG patients, other findings and data support the view that this procedure may lead to the development of other autoimmune states such as SLE. It is evident from previously published data and case reports that patients with one autoimmune disease who underwent thymectomy contracted SLE and became more susceptible to other autoimmune diseases compared to the general population. Post-thymectomy follow-up of patients provides us with mechanistic clues for understanding the development of SLE-MG overlap; hence, in MG patients who have undergone thymectomy, any clinical and immune serological SLE suspicion should be carefully evaluated.

Potential Prognostic Value of Preoperative Leukocyte Count, Lactate Dehydrogenase and C-Reactive Protein in Thymic Epithelial Tumors

Thymic epithelial tumors are the most common mediastinal tumors. Surgery is the mainstay of treatment and complete resection provides the best survival rate. However, advanced tumors often require multimodality treatment and thus we analyzed the prognostic potential of routine circulating biomarkers that might help to risk-stratify patients beyond tumor stage and histology. Preoperative values for white blood cell count (WBC), C-reactive protein (CRP) and lactate dehydrogenase (LDH) were analyzed in 220 thymic epithelial tumor patients operated between 1999 and 2018. Increased CRP levels (>1 mg/dl) were significantly more often measured in thymic carcinoma and neuroendocrine tumors when compared to thymoma. LDH serum activity was higher in thymic neuroendocrine tumors when compared to thymoma or thymic carcinoma. The median disease specific survival was significantly longer in thymoma cases than in thymic carcinoma and neuroendocrine tumors. Increased preoperative LDH level (>240 U/L) associated with shorter survival in thymus carcinoma (HR 4.76, p = 0.0299). In summary, higher CRP associated with carcinoma and neuroendocrine tumors, while LDH increased primarily in neuroendocrine tumors suggesting that biomarker analysis should be performed in a histology specific manner. Importantly, preoperative serum LDH might be a prognosticator in thymic carcinoma and may help to risk stratify surgically treated patients in multimodal treatment regimens.