Thymectomy Research Articles

AB038. PS02.02: Proposal for refined classification of thymectomy

AB038. PS02.02: Proposal for refined classification of thymectomy

The Subxiphoid Approach Leads to Less Invasive Thoracoscopic Thymectomy Than the Lateral Approach.

Video-assisted thoracic surgery (VATS) is widely used in thoracic surgery. This study investigated the usefulness of the subxiphoid approach in thymectomy using VATS techniques. Sixty operations were performed using the lateral approach (n=46) and subxiphoid approach (n=14). Using the lateral approach, 39 partial thymectomies (PT), 5 total or subtotal thymectomies (TT), and 2 total or subtotal thymectomies with combined resection of the surrounding organs (or tissues) (CR) were performed. Using the subxiphoid approach, 11 TT and 3 CR were performed. There were 33 females and 27 males, with a mean age of 55years. The mean maximum tumor diameter was 4.0cm. The operation time was prolonged according to the volume of thymectomy (PT: 119, TT: 234, CR: 347min). Additionally, the intraoperative blood loss increased according to the volume of thymectomy (PT: 29, TT: 47, CR: 345g). To compare the invasiveness of both approaches, we compared 16 TT operations. In the group using the subxiphoid approach, the operation time became shorter (158 vs. 392min), and the blood loss decreased (5 vs. 135g) compared with the lateral approach. Regarding laboratory data, white blood cell counts on postoperative day 1 (1POD) (8200 vs. 10,300/μl) and CRP on 1POD and 3POD (2.8 and 2.8 vs. 7.9 and 10.2mg/dl, respectively) decreased in the subxiphoid approach compared with the lateral approach. The subxiphoid approach leads to a less invasive operation for anterior mediastinal tumors and extends the indications for VATS for invasive anterior mediastinal tumors.

Class I Evidence — After Many Years — Confirms Benefit of Thymectomy for Myasthenia Gravis

Class I Evidence — After Many Years — Confirms Benefit of Thymectomy for Myasthenia Gravis

P18. Thoracoscopic complete thymectomy for thymoma

Background Thymectomy was the standard method for the treatment of thymoma. Video-assisted thoracoscopic (VATS) thymectomy was developed more than 20 years ago and has become a widely accepted surgical approach. We consistently performed 3-port VATS simple thymectomy for thymoma. Our indications for VATS simple thymectomy are thymoma without myasthenia gravis (MG) less than 10 cm in the maximum diameter and positioned below jugular notch of the sternum. Extended surgical procedures are thymectomy with combined resection of internal thoracic artery and vein, lung, pericardium, phrenic nerve and diaphragm.

Oral 3.03: Increasing number of thymectomies performed in the United States

Background Thymoma is a relatively rare disorder, but the true incidence in the United States is unknown because only cases described as “malignant” or “invasive” on final pathology reports are included in cancer registry data. An increasing number of thymomas may be identified incidentally on CT scans done for other purposes. As minimally invasive techniques have become more prevalent, thymectomy may also be offered for more patients. For these reasons, we hypothesized that the use of thymectomy has increased in the U.S. in recent years.

P19: Combined transcervical and bilateral-thoracoscopic extended thymectomy for thymoma with MG

Background To explore the efficacy of combined transcervical and bilateral-thoracoscopic extended thymectomy approach for myasthenia gravis (MG) with thymoma stage I or II.

P25: VATS combined with a subxiphoid incision: a novel approach for large thymoma.

In patients with thymoma larger than 5 cm in diameter, video-assisted thoracoscopic surgery (VATS) remains controversial as an approach for total thymectomy. Aside from the concerns such as possible rupture of tumor capsule, reduced safety margins and increased risk of local recurrence, how to remove specimen of this size from incisions of VATS is another problem that surgeons have to confront. We reported a case of a 47-year-old man who was referred to our department with a huge mass located on the anterior mediastinal and right hemithorax. After careful preoperative evaluation and planning, the tumor was completely removed by VATS and taken out of thoracic cavity through a subxiphoid incision. After resection, histologic analysis confirmed the diagnosis of thymoma B1 type. Postoperative course was uneventful and no adjuvant therapy was offered. The patient has continued to do well with no signs of recurrence at a follow-up of 10 months. We stress that VATS combined with a subxiphoid incision may be a useful surgical option for patients with thymoma larger than 5 cm in size.

P37. Locally advanced thymoma-robotic approach

Background The conventional approach to locally advanced thymoma has been via a sternotomy. VATS and robotic thymectomies have been described but typically are reserved for patients with myasthenia gravis only or for small, encapsulated thymic tumors. There have been few reports of minimally invasive resection of locally advanced thymomas. Our objective is to present a case in which a large, locally advanced thymoma was resected en bloc with the pericardium employing robotic assisted thoracoscopic approach.

P30: A case of anterior mediastinitis and bilateral multiple lung abscesses occurring after TsTET

Trans-subxiphoid thoracoscopic extended thymectomy (TsTET), which can provide a better exposure of bilateral upper thymus lobes and the contralateral phrenic nerve, was reported superior to unilateral thoracoscopic approach in treatment of myasthynia gravis or anterior mediastinal tumour. However, the postoperative complications for TsTET have hardly been discussed. Here we reported a 68-year-old female suffered subxiphoid incision infection, anterior mediastinitis, concomitant bilateral pneumonia and multiple lung abscesses after TsTET. In our experience, because the subxipoid incision, the anterior mediastinum and the bilateral thoracic cavity communicated directly after TsTET, it should be aware of the risk of infection in anterior mediastinitis and bilateral thoracic cavity following subxiphoid incision infection.

Subxiphoid uniportal thoracoscopic extended thymectomy.

The aim of this article is to present a thoracoscopic technique of extended thymectomy through a subxiphoid incision. Six consecutive patients were successively treated with this approach, which provided a good view of the bilateral pleural cavities. The procedure is safe and technically feasible and yields excellent cosmetic results. We believe that subxiphoid uniportal thoracoscopic approach is a satisfactory procedure for performing extended thymectomy in well selected patients.

Two-year outcome of thymectomy with or without immunosuppressive treatment in nonthymomatous myasthenia gravis and its effect on regulatory T cells

BackgroundMyasthenia gravis (MG) is the autoimmune disorder in which the thymus is considered the pathogenic organ. Thymectomy (TE) is a therapeutic option for MG and often ameliorates clinical symptoms. MethodsWe evaluated clinical features and outcomes after TE in patients without thymoma and the influence of TE with or without concomitant immunotherapy on the CD4+CD25+ regulatory T cell subpopulation of lymphocytes in peripheral blood in defined followed groups of nonthymomatous MG patients. ResultsA total of 46 patients with generalized MG who underwent transsternal TE were identified. Neurologic outcomes after TE were favorable for the majority of patients mainly from the group treated with corticosteroids or combined immunosuppressive treatment. TEs with immunosuppressive treatment in MG patients were associated with increased percentages of CD4+CD25+ cells (p<0.001). No significant change in the postoperative levels of CD4+CD25+ cells was observed in thymectomized patients who preoperatively only received pyridostigmine. Also their clinical response to TE after 2years of follow-up was worst of all followed groups. ConclusionsThe exact mechanism by which TE ameliorates symptoms of MG is yet not clear. These observations indicate that increased percentages of CD4+CD25+ T cells in MG may be related to disease stability and that TE and synergistic effect with concomitant, continuing immunotherapy augmented the proportion of CD4+CD25+ T cells. On the basis of our observations TE alone is not enough to increase the number of circulating CD4+CD25+ regulatory T cells and to establish complete stable remission.

The relationship between myasthenia gravis and the different pathological type of thymoma patients' operation and prognosis

To evaluate the different pathological and clinical characteristics of thymomas with and without myasthenia gravis (MG) and to determine whether the presence of MG influences the prognosis in thymoma patients. The clinical data from 228 consecutive patients (median sternotomy were used in 153, video-assisted thoracoscopic themectomy were used in 75) operated on from January 1992 to December 2007 was analyzed retrospectively. These thymoma patients had been subdivided into two groups: thymoma with MG (n = 125) and thymoma without MG (n = 103). All thymic epithelial tumors were classified according to the WHO histologic classification and the Masaoka clinical staging system. The result was evaluated according to the Myasthenia Gravis Foundation of America's criterion. The clinical features of the 2 test was compared between the two groups by χ² test, and the survival were compared between the two groups by Cox analysis. There were no peri-operative deaths. 19 cases were inoperable (6 in the group with MG, 13 without MG (χ² = 4.52, P = 0.035)). The proportions of type A and thymic carcinoma were 0 in the group with MG, 10.5% (11/103) and 11.6% (12/103) respectively in the group without MG. According to the Masaoka's clinical staging, in the group MG, 24.8% (31/125) patients were stage III and IV; in the group without MG, 33.0% (34/103) patients were stage III and IV. There was a significant difference between hyperplastic paraneoplastic thymus coexisting in 28.8% (36/125) patients with MG and only 5.8% (6/103) in patients without MG (χ² = 20.91, P = 0.000) Microthymoma was identified in the paraneoplastic thymus of 3 patients with MG. There were 198 patients followed up, the rate was 86.8% (198/228). There was no recurrence in patients with type A and a few patients with type AB, B1, B2, B3 thymoma and thymic carcinoma recurred. The actuarial 5- and 10-year survival rates were 89.3% and 81.2% for patients with MG respectively, and 90.0% and 78.9% for patients without MG respectively. Within 5 years postoperatively, 6 of 9 patients with MG died of myasthenia crisis, while 6 out of 7 deaths in patients without MG were attributable to inoperable tumors (stage IV) and thymic carcinoma. The existence of myasthenia gravis has little influence on the prognosis of thymomas, but it is good for early diagnosis and treatment. Extended thymectomy should be performed to all patients with thymoma, no matter they have myasthenia gravis or not. The main cause of death is myasthenia crisis for thymoma patients with MG and stage IV and (or) thymic carcinoma for patients without MG.

The impact of thymectomy during infancy on T-cell immunity

The impact of thymectomy during infancy on T-cell immunity

Protective effect of ambroxol on perioperative inflammatory response and lung protection in elderly patients with myasthenia gravis

Objective To investigate the protective effects of ambroxol on lung during perioperation in elderly patients with myasthenia gravis. Methods 58 elderly patients diagnosed as myasthenia gravis combined with thymic disease were divided into treatment group and control group randomly. During the perioperation, the treatment group was treated with ambroxol, while the control group was not. Comparative analysis of pulmonary complications, pulmonary ventilation indexes, blood gas indexes, and serum concentration of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-10 was performed. Results The incidence rate of postoperative pulmonary complications (pulmonary atelectasis, pneumonia and bronchitis) was significantly lower in the treatment group in the control group (9.4% vs.15.6%, P<0.05). Peak inspiratory pressure (PIP) and resistance of air way (RAW) were lower in treatment group than in control group 〔(22.32±3.43) cmH2O vs. (26.54±4.81) cmH2O, (29.17±5.74) cmH2O·L-1·s-1vs. (34.47±7.94) cmH2O·L-1·s-1, both P<0.05〕, while compliance of lung (CL) was higher in treatment group than in control group 〔(106.04±14.73)ml/cmH2O vs. (95.11±9.50) ml/cmH2O, P<0.05〕. Two days after operation, PaO2, SaO2 and PaO2 /FiO2 were significantly higher in treatment group than in control group 〔(89.66±13.23) mmHg vs. (70.94±12.75) mmHg, (96.95±2.65)% vs. (89.44±2.78)%, (219.47±54.05)mmHg vs. (187.38±37.72) mmHg, respectively, all P<0.05〕. Serum concentration of CRP, TNF-α, IL-1β were lower and serum level of IL-10 was higher in treatment group than in control group 〔(29.37±14.87)mg/L vs. (43.94±21.42) mg/L, (35.55±4.74)μg/L vs. (52.80±6.63) μg/L, (17.06±6.85)μg/L vs. (28.62±7.72) μg/L〕, 〔(132.84±12.91)μg/L vs. (87.18±16.37)μg/L, respectively, all P<0.05〕. Conclusions Ambroxol hydrochloride can effectively reduce the incidence rate of postoperative pulmonary complications after thymectomy, improve the pulmonary ventilation function, and inhibit the inflammatory reaction in elderly patients with myasthenia gravis, which is worthy of wide application in the perioperation. Key words: Lung; Myasthenia gravis; Ambroxol; Inflammation

Thymic artery: uncommon origin from proximal aortic arch or distal ascending aorta.

Internal thoracic and inferior thyroid arteries mainly supply the thymus. However, very few studies have been reported on the arterial variations of the thymus. The first author, a cardiac surgeon, happened upon a thymic artery arising from either proximal aortic arch or distal ascending aorta in a few cases during routine cardiac surgery in infants and neonates. Hence a study on the prevalence of the variant thymic artery during open heart surgery was contemplated, as knowledge of its presence could avoid its injury during surgical and diagnostic procedures of the region. The prevalence of the variant thymic artery was observed during 100 consecutive cardiac surgeries in infants and neonates. In addition to two branches from internal thoracic and inferior thyroid arteries, a thymic artery originating from the distal ascending aorta or proximal arch was found in 15 (15%) out of 100 patients who underwent open heart surgery for the correction of congenital heart defects. The artery took origin from the anterior surface of aorta, a little to the left. These were small arteries, single in origin, which started at right angles from the aorta and pierced the pericardium at its reflection, from visceral to parietal, to reach the posterior surface of the thymus where they divided into two branches, one for each lobe. Since this variant artery was present in 15% cases, being aware of its presence can help prevent troublesome bleeding during surgical thymectomy, and more importantly, during surgical and diagnostic interventions in the mediastinum.

Technical points on video assisted thoracoscopic thymectomy for thymoma accompanied by myasthenia gravis

Objective To explore the value of video-assisted thoracoscopic thymectomy in the treatment of thymoma accompanied by myasthenia gravis. Methods In this study, forty-two patients who were preoperatively con- firmed to be thymoma accompanied by myasthenia gravis from 2008.1 to 2012.12 were treated using VATS,including type Ⅰ in 23 cases, type Ⅱ a in 11 cases, type Ⅱ b in 7 cases, and type Ⅲ in 1 case. Thymectomy and dissection of all fatty tissue anterior to the pericardium were performed in all cases. The operation time, blood loss, chest drainage time,hospital stay and outcomes were recorded and compared. Results In this group, one patient showed myasthenic crisis after surgery and recovery well after treated by ventilatory support, the patients had fewer blood loss（ 〈 35mL）, shorter operation and postoperative drainage time, and shorter postoperative hospital stay. Conclusion Extended thymectomy by VATS is safe and feasible w/th the advantage of less invasion, less surgical trauma and pain,lower rate of complication, and good curative effect. Key words: Video-assisted thoracoscopic surgery ; Extended thymectomy; Myasthenia Gravis

Number of memory T cells in myasthenia gravis

To determine the altered number of memory T cells in myasthenia gravis (MG) patients and confirmed the existence of immune memory disorder. A total of 27 MG cases (12 females, 15 males) undergoing expanded thymectomy at our hospital between 2009-2012. They were divided into 3 group of eutherapeutic (clinical relative score ≥ 50%), invalid (clinical relative score ≤ 25%) and improved (25% < clinical relative score <50%). Control group was composed of 17 cases of healthy subjects without immune system related disease. Flow cytometry was employed to detect the numbers of CD4⁺, CD8⁺, CD4⁺ CD45RO⁺, CD8⁺ CD45RO⁺, CD4⁺ CD45RO⁺ CCR7⁺, CD8⁺ CD45RO⁺ CCR7⁺, CD4⁺ CD45RO⁺ CD44(high) and CD8⁺ CD45RO⁺ CD44(high) T cells in PBMCs of 27 MG patients and 17 normal controls. As compared with healthy controls, the abnormal rates of CD4⁺ and CD8⁺ T cells were significantly higher in patients (P < 0.05), the number of CD4⁺ CD45RO⁺ CCR7⁺ T cells was significantly higher [(9.9 ± 5.5)% vs (6.6 ± 3.0)%, P = 0.012], the number of CD4⁺ CD45RO⁺ CD44(high) T cells was significantly higher [(6.8 ± 2.4)% vs (5.0 ± 3.0)%, P = 0.04] and the number of CD8⁺ CD45RO⁺ CCR7⁺ T cells was also significantly higher (P < 0.001). MG patients had immune disorders. And increased number of memory T cells and their activation may be pathogenesis of MG.

Clinical characteristics of patients with myasthenia gravis associated with other autoimmune diseases

Objective To analyze the clinical characteristics, drug efficacy and prognosis of patients with myasthenia gravis (MG) associated with other autoimmune diseases. Methods Eighty-three MG patients were divided into 2 groups. One group included MG patients with autoimmune diseases (AIDMG, N = 24), and the other included MG patients without autoimmune diseases (NAIDMG, N = 59). Firstly, clinical features such as sex, age of onset, initial symptoms and thymus abnormalities were compared between patients with AIDMG and NAIDMG. Secondly, effect of different therapies, including pyridostigmine, corticosteroids, immunoglobulin, immunosuppressants and thymectomy was compared between 2 groups. Finally, prognosis including relapse rate and recurrence time during the first 2 years after MG onset was compared. Whether and when ocular myasthenia gravis (OMG) progressing to general myasthenia gravis (GMG) and the first onset of GMG symptoms during the first 2 years were also compared between 2 groups. Results The difference of gender predominance ( χ 2 = 8.467, P = 0.004), ptosis affecting left or right or both sides ( χ 2 = 9.830, P = 0.007) and disease course within 2 years after onset ( χ 2 = 15.255, P = 0.001) between AIDMG group and NAIDMG group were statistically significant. Other clinical features such as age of onset ( χ 2 = 1.728, P = 0.228), initial symptoms ( χ 2 = 0.252, P = 0.791), thymus abnormalities ( χ 2 = 3.200, P = 0.202) were not significantly different between 2 groups. Differences of therapeutical effect such as pyridostigmine ( χ 2 = 0.411, P = 0.395), corticosteroids ( χ 2 = 0.156, P = 0.513), immunoglobulin ( χ 2 = 0.359, P = 0.462), immunosuppressants ( χ 2 = 0.081, P = 0.526) and thymectomy ( χ 2 = 0.337, P = 0.391) between 2 groups were not statistically significant. The ratio of OMG progressing to GMG ( χ 2 = 1.826, P = 0.148), time of progressing (Fisher's exact test: P = 0.639), first onset symptom (Fisher's exact test: P = 0.196) and recurrence time (Fisher's exact test: P = 1.000) were not significantly different between 2 groups. Conclusions AIDMG was more common in female patients. Bilateral ptosis involvement at the same time was more common in AIDMG. Relapse rate during the first 2 years after MG onset was higher in AIDMG than that in NAIDMG. doi: 10.3969/j.issn.1672-6731.2014.10.009

P37. Surgical strategy for stage III thymoma by video assisted thoracoscopic surgery (VAT-T) with lateral thoracotomy

Background Whether thoracoscopic surgical treatment is acceptable for invasive thymoma, one of main anterior mediastinal tumor remains to be still controversial. However, we performed the video-assisted thoracoscopic surgery for Masaoka stage III thymoma invaded to adjacent organs after acquisition of the patient permission. We examined the feasibility and efficacy of video-assissted thoracoscopic thymectomy (VAT-T) with lateral thoracotomy for stage III thymoma.

P3. Therapeutic efficacy of single incision thoracoscopic surgery (SITS) for stage I lung cancer

Objective Whether thoracoscopic surgical treatment is acceptable for thymoma, one of main anterior mediastinal tumor remains to be still controversial. However, we performed the video-assisted thoracoscopic surgery (VATS) for Masaoka stage III thymoma invaded to adjacent organs after acquisition of the patient permission. We examined the feasibility of video-assisted thoracoscopic thymectomy (VAT-T) with lateral thoracotomy for Masaoka stage III thymoma. We introduce our representative thoracoscopic operations.