Thymectomy by partial sternotomy for the treatment of myasthenia gravis

Myasthenia Gravis and Thymectomy

Myasthenia gravis (MG) is a rare autoimmune neuromuscular disorder. Though MG was diagnosed four centuries ago, its rational management started in 1930s. In the present era, MG is managed by multimodality care including pharmacological agents, plasmapheresis, intravenous immunoglobulins, and surgical thymectomy. Thymectomy has evolved from open trans-sternal to video-assisted thoracoscopic and robotic thymectomy. In this article, the concise history of MG, its clinical features, diagnosis, and management are described.

Risk factors of myasthenia crisis after thymectomy among myasthenia gravis patients: A meta-analysis

BACKGROUND

The purpose of the study was to determine the risk factors of post-surgery myasthenia crisis (PMC) among myasthenia gravis (MG) patients.

METHODS

A meta-analysis to synthesize all eligible literatures was conducted to analyze PMC predictors among MG patients.

RESULTS

A total of 15 trials with 2626 patients were included for the meta-analysis. As a result, patients with history of MC (RR = 3.36, 95%CI: 2.46-4.59, P < .001), generalized MG (RR = 0.39, 95%CI: 0.26-0.59, P < .001), bulbar symptom (RR = 3.59,95%CI:2.53-5.09, P < .001), thymoma (RR = 2.10, 95%CI:1.37-3.21, P = .001), post-surgery morbidity presence(RR = 2.59, 95%CI:1.90-3.54, P < .001), high-dose pyridostigmine usage (SMD = 0.480, 95%CI: 0.35-0.61 P < .001) tended to develop PMC. Large dose of steroid may reduce the incidence of PMC (RR = 0.41 95%CI: 0.18-0.94, P = .036). Regular steroid use (P = .066), immunosuppressive therapy (P = .179), gender (P = .774), and age at thymectomy (P = .212) had no impact upon PMC development.

CONCLUSION

History of PMC, thymoma, generalized MG, bulbar symptom, and concomitant complication are the risk factors of PMC.

Video-assisted thoracoscopic surgery thymectomy versus open thymectomy in patients with myasthenia gravis: a meta-analysis

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) thymectomy has become a feasible treatment for myasthenia gravis (MG) in recent years. The objective of the present meta-analysis was to evaluate the perioperative characteristics, safety, and completely stable remission rate in patients with MG who received VATS or open thymectomy (OT).

METHODS

We searched PubMed, Embase, ScienceDirect, Web of Science, and CNKI for related articles using combinations of the search terms video-assisted thoracoscopic thymectomy, transsternal thymectomy, and MG. The inter-study heterogeneity was assessed by χ²-based Q statistics, and the extent of inconsistency was generated by I² statistics.

RESULTS

A total of 12 studies with 1173 patients were included, and there was no difference in the operation time (p = 0.08) and ICU time (p = 0.14) between the two groups, but VATS thymectomy was associated with less intra-operation blood loss and hospital time (p < 0.00001). VATS was also associated with lower rates of total complication (OR =0.59; 95% CI, 0.37-0.94; p = 0.03) and myasthenic crisis (OR = 0.51; 95% CI, 0.28-0.92; p = 0.03), but the rates of pneumonia (OR = 0.59; 95% CI, 0.29-1.32; p = 0.21) and complete remission rate (CSR) (OR = 0.64; 95% CI, 0.38-1.09; p = 0.10) had no obvious differences between the VATS and OT groups.

CONCLUSION

Patients with MG undergoing VATS thymectomy achieved better surgical outcomes and fewer complications than those who received OT.

Thymectomy by video-assisted thoracoscopy versus open surgical techniques

Objective

This study was conducted to compare operative variables and postoperative outcomes in adult patients with myasthenia gravis undergoing thymectomy through 3 different operative techniques: total median sternotomy, partial median sternotomy, and video-assisted thoracoscopy.

Methods

30 patients aged 20–65 years were included in this study. They were subdivided into: group A: 8 patients undergoing thymectomy through a total median sternotomy; group B: 9 patients undergoing thymectomy through a partial median sternotomy; and group C: 13 patients undergoing thymectomy through video-assisted thoracoscopy. Preoperative, intraoperative, and postoperative variables, and mortality were compared among groups.

Results

Preoperative variables were well matched in all groups. Operative time was significantly longer in group C. There was no intraoperative complication in any group. Postoperative length of hospital stay was significantly shorter in group C. Postoperative complications occurred in 3 (10%) patients, mostly in groups A and B. There was no perioperative mortality in any group.

Conclusions

Video-assisted thymectomy is as effective as the traditional open surgical approaches for thymectomy in the management of patients with myasthenia gravis. In addition, the improved cosmesis of the video-assisted approach ideally should lead to earlier thymectomy in patients with myasthenia gravis.

Thymectomy through lateralized partial sternotomy

A young woman with nonthymomic myasthenia gravis with failure of medical treatment was offered thymectomy through partial sternotomy. Shifting of vertical arm of “L” incision laterally avoids fracture of opposite sternal flange and provides better sternal stability postoperatively.

Limited upper sternotomy in general thoracic surgery

PURPOSE

To evaluate the status of limited upper sternal split in general thoracic surgery.

METHODS

We reviewed the clinical files of 100 consecutive patients operated on through limited upper sternotomy at a hospital in Italy during the 10 years between January 1995 and December 2004.

RESULTS

Thymus surgery represented the main indication for this approach (n = 51): for myasthenia without thymoma in 28 patients, for thymus neoplasms with or without myasthenia in 22, and for intrathymic parathyroid adenoma in 1. Thyroid surgery constituted the second main indication for upper sternal split (n = 32) for benign retrosternal goiter in 18 patients, for mediastinal nodal metastasis of thyroid cancer in 11, and for malignant retrosternal goiter in 3. The remaining indications were as follows: to assess residual disease following chemotherapy for Hodgkin's disease in 7 patients and for non-Hodgkin lymphoma in 1; for tracheal surgery in 7; and for excision of nodal mediastinal metastasis of non-thyroid cancer in 2. All operations were completed through the upper sternal split. There was no surgical mortality but complications developed in eight patients.

CONCLUSION

The upper sternal split provides a satisfactory access to perform a surgical procedure in the superior mediastinum in most diseases. The procedure is safe and involves minimal surgical trauma.

Partial median sternotomy: an attractive approach to mediastinal parathyroid disease

BACKGROUND

Parathyroid exploration through a standard cervical approach is adequate for the resection of most mediastinal parathyroid glands. A subset of mediastinal parathyroid glands causing hyperparathyroidism, however, cannot be removed in this manner.

STUDY DESIGN

We reviewed our experience with the use of partial median sternotomy in the treatment of these patients.

RESULTS

Over a 14-year period, all but 10 of 937 (1.1%) consecutive patients explored for hyperparathyroidism by a single endocrine surgeon were treated by a cervical approach. Partial median sternotomy was performed in 10 cases and was successful in seven cases (70%), with conversion to a complete sternotomy being required in three cases. Six of these seven patients had failed a previous parathyroid exploration (86%), including one patient who had a previous complete sternotomy. Cure of hyperparathyroidism was achieved in all seven patients undergoing partial median sternotomy. In five patients a mediastinal parathyroid gland was removed (71%), and in one patient a parathyroid adenoma in the carotid sheath was eventually found, and the location of the hyperfunctioning parathyroid gland in one patient was never determined although the patient was cured. The mean length of hospital stay after a partial median sternotomy was 2.6 days. One patient sustained a recurrent laryngeal nerve injury at the time of a repeat cervical exploration and partial median sternotomy.

CONCLUSIONS

Rarely, mediastinal parathyroid glands cannot be resected through a cervical approach. In these cases the use of partial median sternotomy is an attractive technique in achieving cure of hyperparathyroidism and is associated with minimal morbidity and a short length of hospital stay.

Factors influencing the outcome of transsternal thymectomy for myasthenia gravis

BACKGROUND

Thymectomy is one of the current treatment strategies for patients with myasthenia gravis (MG); however, the selection criteria for surgery remain controversial.

METHODS

The demographic data and the surgical results of 168 patients with MG who underwent transsternal thymectomy from June 1986 to December 2000 were retrospectively reviewed. Follow-up information was obtained by review of the hospital records or telephone contact. The postoperative status of MG was assessed at the interval of 1, 3 and 6 months and then annually. The complete remission rate (CRR) between groups was compared.

RESULTS

A total of 168 patients, including 69 male patients and 99 female patients, with a mean age of 38.3 years (range 13-80 years), were analyzed. The symptom duration before operations was from 1 to 312 months with a mean of 33.8 months. Complete follow-up information was obtained on 154 patients (91.6%) with a mean follow-up duration of 98.9 months. Complete remission was achieved in 89 of 154 patients (57.8%) and marked clinical improvement in 47 patients (30.5%). Total improvement rate was 88.3%. Seventeen of 24 patients (70.8%) with ocular MG and 18 of 35 patients (51.4%) with thymoma had reached complete remission during the follow-up period. The CRR increased with each consecutive year and reached the plateau in the fourth postoperative year. There was no surgical mortality. The complication rate was 16.6%. Univariate analysis demonstrated that age <35 years old (P = 0.0001), symptom duration before operation <24 months (P = 0.01) and absence of preoperative steroid treatment (P = 0.04) were favorable prognostic factors. Multivariate Cox regression analysis revealed age <35 years old (odds ratio = 3.645, P = 0.001), symptom duration before operation <24 months (2.311, P = 0.041) were favorable prognostic factors for patients having transsternal thymectomy.

CONCLUSIONS

Transsternal thymectomy is feasible in the management of patients with MG at all stages with high improvement rate and low surgical morbidity. Those patients aged 35 years or less at operation, with symptoms developed <24 months before operation, may benefit more from thymectomy. MG patients with thymoma did as well as patients without thymoma, and 18 of 35 patients with thymoma had reached complete remission during the follow-up period. Thymectomy seems to be beneficial also for ocular MG.

Application of Robotic-Assisted Techniques to the Surgical Evaluation and Treatment of the Anterior Mediastinum

BACKGROUND

We report our initial experience with the application of robotic-assisted technologies to the treatment of diseases of the anterior mediastinum.

METHODS

Between October 2001 and December 2003, 18 consecutive patients with anterior mediastinal masses were referred for diagnosis and treatment. Fifteen patients underwent robotic-assisted surgery with the da Vinci robotic system. A single surgical team performed all operations. Resection was accomplished by either median sternotomy or robotic-assisted techniques.

RESULTS

Fourteen patients underwent successful robotic-assisted thymectomy. One patient underwent robotic-assisted biopsy of a mass that was later determined to be a poorly differentiated carcinoma, 3 patients underwent complete thymectomy by median sternotomy for biopsy-proven extracapsular thymoma, 7 patients had thymoma, and 3 had myasthenia gravis. There were 2 patients each with benign thymic cysts and thymic hyperplasia. Primary thymic carcinoid, thymolipoma, papillary thyroid cancer, and poorly differentiated carcinoma were present in 1 patient each. No conversions, intraoperative complications, or deaths occurred in the 15 patients who underwent robotic-assisted resection. The mean operative time was 96 minutes (range 62 to 132 minutes). The mean robotic time was 48 minutes (range 22 to 76). The median hospital stay was 2 days. All patients are doing well, with a median follow-up of 1 year.

CONCLUSIONS

Robotic-assisted surgery of the anterior mediastinum, and particularly thymectomy, can be performed safely and efficiently. The increased visualization and instrument dexterity afforded by this technology provides an optimal minimally invasive approach to the anterior mediastinum. From this experience we have formulated a comprehensive treatment algorithm for the surgical evaluation and treatment of patients with anterior mediastinal diseases.

Resultado da timectomia ampliada no tratamento de pacientes com Miastenia gravis

INTRODUÇÃO: Diversas variações da timectomia podem ser realizadas, dentre elas a transesternal ampliada. A literatura sugere que, quanto mais extenso o procedimento para ressecção da glândula e tecidos do mediastino anterior, melhores os resultados e prognóstico. OBJETIVO: Avaliar retrospectivamente a resposta à timectomia ampliada em portadores de Miastenia gravis. MÉTODO: Foram avaliados 46 portadores de Miastenia gravis, submetidos à plasmaferese pré-operatória e à timectomia ampliada, entre agosto de 1992 e janeiro de 2003, divididos em três grupos, segundo o tempo decorrido desde o início dos sintomas: menor que 12 meses, 13 a 24 meses e maior que 25 meses. RESULTADOS: Trinta e um pacientes eram do sexo feminino e 15 do masculino. A média de idade foi de 30 anos. O tempo médio de evolução da doença foi de 26,3 meses. O acompanhamento ambulatorial pós-operatório foi em média de 26,6 meses. Quanto ao grau de resposta à timectomia, 89% dos pacientes tiveram boa resposta, sendo que 50% apresentaram remissão completa. Ocorreu um óbito nesta série. O exame anatomopatológico demonstrou que a hiperplasia tímica foi o achado mais freqüente. Apenas 3 pacientes (6,5%) apresentaram timomas benignos. Em 5 pacientes (10,8%) encontramos tecido tímico extraglandular: na gordura peritímica em 2 deles, na gordura pericárdica em 1, junto ao nervo frênico esquerdo em outro e na janela aorto-pulmonar em outro. CONCLUSÃO: A timectomia ampliada para tratamento da Miastenia gravis mostrou-se segura, eficiente, e apresentou alta porcentagem de remissão completa. Houve a detecção de tecido tímico extraglandular em alguns pacientes. Tão logo seja feito o diagnóstico, está indicada como terapêutica associada à plasmaferese pré-operatória e à medicamentosa, independentemente da idade, patologia tímica, e início dos sintomas.

Prognostic factors for myasthenic crisis after transsternal thymectomy in patients with myasthenia gravis

OBJECTIVE

The purpose of this study was to assess which clinical features of patients with myasthenia gravis predict postoperative respiratory problems due to myasthenic crisis after transsternal thymectomy.

METHODS

One hundred twenty-two patients who underwent transsternal thymectomy in our institute were analyzed retrospectively. Fourteen of those experienced myasthenic crisis and required prolonged (48 hours or more) postoperative mechanical ventilation. The following factors were evaluated: sex, age, body mass index, grade of symptom, disease interval, existence of thymoma, history of preoperative crisis, doses of anticholinesterase drugs, steroid use, pulmonary function, serum anti-acetylcholine receptor antibody, history of pulmonary disease, presence of other disease, operation time, and blood loss.

RESULTS

Univariate analysis revealed preoperative bulbar symptoms (odds ratio = 14.246, P =.001), history of preoperative myasthenic crisis (7.091,.018), and preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L (4.098,.044) were prognostic factors for postoperative myasthenic crisis. On the other hand, multivariate logistic regression analysis revealed preoperative bulbar symptoms (33.333,.004), preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L (7.874,.020), and intraoperative blood loss > 1000 mL (18.519,.048) were prognostic factors for postoperative myasthenic crisis.

CONCLUSIONS

In this study, postoperative myasthenic crisis after transsternal thymectomy in 122 patients with myasthenia gravis was affected by the existence of preoperative bulbar symptoms, history of preoperative myasthenic crisis, preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L, and intraoperative blood loss > 1000 mL. Meticulous preoperative and postoperative care should be carried out to prevent postoperative myasthenic crisis in patients with these prognostic factors.

Video-assisted thoracoscopic extended thymectomy and extended transsternal thymectomy (T-3b) in non-thymomatous myasthenia gravis patients: remission after 6 years of follow-up

The aims of this study were to assess the efficacy of video-assisted thoracoscopic extended thymectomy (VATET) as a treatment for myasthenia gravis (MG) and to identify prognostic factors for thymectomy success. Clinical efficacy and variables influencing outcome were assessed by life-table and Cox proportional hazards regression analysis. Complete stable remission (CSR), as defined by the MGFA Medical Task Force, was the end point for efficacy. VATET was performed in 159 MG patients and T-3b in 47 MG patients. At 6 years of follow-up, CSR, assessed by life-table analysis, was 50.6% in non-thymomatous VATET patients and 48.7% in non-thymomatous T-3b surgery. By univariate analysis, the presence of thymic hyperplasia (P=0.0002) and treatment only with anticholinesterases (P<0.0001) were positively associated with the probability of CSR. By multivariate analysis, the chance of complete remission was significantly increased by the use of anticholinesterases (odds ratio [OR] 2.45; 95% confidence interval [CI] 1.44-4.17; P=0.001) and the presence of thymic hyperplasia (OR 1.96; 95% CI 1.05-3.68; P=0.036). VATET seems to be effective in inducing CSR in MG with an efficiency similar to that of the T-3b transsternal (TS) approach; it is easy to perform in experienced hands and is associated with low morbidity and negligible esthetic sequelae.