Transsternal Extended Thymectomy Research Articles

Anterior chest wall lifting methods for mediastinal approach-literature review.

Background and ObjectiveFor the purpose of facilitating a wide view and working space during surgery such as a thymectomy procedure, as well as that for treatment of anterior mediastinal lesions, anterior chest wall lifting began to be employed. In this article, previous reports of various kinds of chest wall lifting methods are reviewed.MethodsThe present study focused on procedures used for anterior chest wall lifting in a review of related studies primarily available in English. A search of the PubMed database was conducted in 1st March 2016. The first description about lifting method was reported in 1988.Key Comments and FindingsAlthough objective evaluation regarding the effectiveness of lifting is difficult, in view of a balance among safety, reliability, and minimal invasiveness, surgeons may consider chest wall lifting as an optional method.ConclusionsAnterior chest wall lifting began to be employed for enlarging the working space long before the advent of endoscopic surgery. Some originally developed retractors were used in transcervical thymectomy procedures. After general acceptance of transsternal extended thymectomy for myasthenia gravis, these transcervical approaches remained an important option along with anterior chest wall lifting. Thoracoscopic surgery for the treatment of anterior mediastinal lesions was introduced in the 1990s. Particularly in cases of surgery in the supine position, various creative methods and devices of lifting the sternum body, the anterior part of the rib, or the xiphoid process were reported.

Minimal Access Surgery for Thymoma.

Thymoma is a rare epithelial tumor of the thymus gland. Despite rarity, it is the most common tumor of the anterior mediastinum. Surgical resection in the form of extended thymectomy is the gold standard operation. Conventionally and even in the current era of significant advances in the minimally invasive surgery, open transsternal extended thymectomy is considered the gold standard, particularly for advanced-stage tumors. There is however significant evidence now available for the use of minimally invasive approaches for early-stage thymomas. This article aims to discuss the various minimally invasive approaches currently being employed for thymomas.

Minimally invasive surgical procedures for thymic disease in Asia.

Video-assisted thoracic surgery (VATS) procedures for thymic tumors and myasthenia gravis were introduced in Asia in the middle 1990s in at least two regions, Hong Kong and Japan. To overcome difficulties in obtaining a wide view of the anterior mediastinum, several methods for lifting the sternum or anterior chest wall have been presented, mainly by Japanese surgeons. More recently, single port VATS through a subxiphoid incision was also introduced in Japan. The long-term outcome of a VATS extended thymectomy for myasthenia gravis has been shown to be comparable to that of a trans-sternal extended thymectomy, while the long-term outcome of a VATS thymectomy for thymic epithelial tumors remains to be elucidated. Nevertheless, its indication for tumors in an early stage is now widely accepted, and the number of VATS procedures is steadily increasing in Japan and China. Single-port VATS through a subxiphoid incision was developed in Japan and might become accepted as a useful approach in the near future when combined with robot-assisted thoracoscopic surgery. In addition, robot-assisted thoracoscopic surgery for the thymus has also been introduced in some areas in Asia. Although few of those surgical procedures for the thymus have been performed, results obtained thus far indicate that it might be preferable to lung resection. Several novel minimally invasive thymectomy techniques have been invented and developed in Asia, and further advancements in this field by Asian surgeons are anticipated.

Cellular immunity following video-assisted thoracoscopic and open resection for non-thymomatous myasthenia gravis

Myasthenia gravis (MG) is a common chronic disorder of neuromuscular transmission, frequently treated surgically. Little is known about perioperative cellular immune responses following video-assisted thoracoscopic surgery (VATS) when compared with open resection. Between January and December 2009, 127 patients with non-thymomatous MG underwent surgery, with 54 undergoing VATS and 73 undergoing conventional trans-sternal extended thymectomy (TS). Operative details, ectopic thymic tissue findings, postoperative concentrations of serum immunoglobulin and complement components as well as T-cell immunity were compared in the VATS and TS groups. There were no between-group differences in patients' age, gender, preoperative duration of MG and operation time. Patients who underwent VATS had a lower rate of postoperative stay in the intensive care unit (P = 0.02), less blood loss (P = 0.01) and a lower probability of ectopic thymic tissue. Prominent cellular immunity difference occurred in serum IgG and C3 concentrations and CD4(+) and CD8(+) T-cell counts between the VATS and TS groups. In VATS patients, serum IgG concentration increased slightly on postoperative days 1 and 3. C3 concentration increased gradually in both groups after surgery, but decreased by postoperative day 7. CD4(+) and CD8(+) T-cell counts were relatively stable postoperatively in the VATS group, but were markedly increased in the TS group on postoperative days 1 and 3, with CD4(+), but not CD8(+), T-cells declining on postoperative day 7. VATS for non-thymomatous MG has short-term advantages, with less effect on cellular immune responses than open resection.

Video-assisted thoracoscopic surgery versus sternotomy in treating myasthenia gravis: Comparison by a case-matched study

To clarify the efficacy of a right-sided video-assisted thoracoscopic extended thymectomy (RtVATET) as a surgical alternative for myasthenia gravis (MG) and to determine the optimal timing for a thymectomy. Thirty-three patients who underwent RtVATET in two institutes were enrolled in this study. Another 66 paired, traditional trans-sternal extended thymectomy (TET) patients from the registered database were used to compare these two surgical modalities for MG. Mean blood loss was 88.5 ml in RtVATET and 226.8 ml in TET group patients (P < 0.001). Mean operation duration was 207.3 min for RtVATET and 172.8 min for TET patients (P = 0.003). Complete stable remission (CSR) rates and total improvement rates for the RtVATET and TET patients were 42.4% vs 60.6% (P = 0.087) and 87.9% vs 90.1% (P = 0.637), respectively. Furthermore, when we focused on the minor grades (classes I and IIa), TET groups showed significantly better CSR than the RtVATET groups (P = 0.012), but there was no statistically significant difference for the more severe grades (classes IIb and III, P = 0.827). Both RtVATET and TET are effective for treating MG, although this study does indicate an advantage for TET. We suggest that a thymectomy should therefore be performed earlier, or that the procedures should be extensive enough to remove all of the tissue that contains thymic tissue.

Bilateral video-assisted thoracoscopic thymectomy has a surgical extent similar to that of transsternal extended thymectomy with more favorable early surgical outcomes for myasthenia gravis patients

This study aimed to introduce the authors' surgical technique of bilateral video-assisted thoracoscopic thymectomy (BVT) and to compare their early surgical results between BVT and transsternal extended thymectomy (T3-b thymectomy) for patients with myasthenia gravis (MG). The records of 114 patients who underwent either BVT (n = 55) or T3-b thymectomy (n = 59) for MG were reviewed retrospectively between January 2006 and November 2009. No surgical mortality or major morbidity occurred in either group. There was no conversion to open thymectomy, and no statistical difference was found in operation time between the two groups (112.2 ± 26.2 min for BVT vs. 130.7 ± 27.3 min for T-3b; p = 0.908). The duration of the chest tube, the length of the intensive care unit (ICU) or hospital stay, and the duration of opioid use for pain control were shorter in BVT group. The estimated blood loss and the total amount of drainage were greater in the T3-b thymectomy group. The specimen weights retrieved by BVT (72.5 ± 61.6 g) were similar to those retrieved by T3-b thymectomy (74.1 ± 38.2 g, p = 0.63) in nonthymomatous MG. The BVT was a safe procedure with a surgical extent and amount similar to those of T-3b thymectomy and less invasive for patients with MG. Long-term follow-up assessment and more extensive data are mandatory to verify the early surgical outcomes.

Comparison of Outcomes After Extended Thymectomy for Myasthenia Gravis: Bilateral Thoracoscopic Approach Versus Sternotomy

Minimally invasive thymectomy procedures have been proposed for nonthymomatous myasthenia gravis. However, few reports stressed that the lower invasiveness or cosmetic benefits also evaluated the rationale of a thymectomy, which is performed to remove as much thymic tissue as possible. We retrospectively reviewed 30 consecutive patients who underwent a bilateral video-assisted thoracoscopic extended thymectomy (VATET) and compared the results with those of 26 patients who underwent a transsternal extended thymectomy (TSET) to determine the amount of removed thymic tissue and clinical prognosis. The amount of blood loss during the operation for VATET (median 60 mL; range nearly 0 to 940 mL) was significantly lower as compared with that of TSET. The median weight of removed thymic tissue (37.0 g; 18.3 to 100.0 g) and remission rates (1 y: 12.5%; 3 y: 30.8%; 4 y: 44.4%) of VATET were comparable with those of TSET. The VATET group had a similar amount of thymo-fatty tissue removed and feasible clinical outcomes as compared with the TSET group, indicating that VATET provides a proper balance between less invasiveness and radical capability.

Transsternal Maximal Thymectomy is Effective for Extirpation of Cervical Ectopic Thymic Tissue in the Treatment of Myasthenia Gravis

PurposeExtensive extirpation of cervico-mediastinal adipose tissue increases the chance of removing ectopic thymic tissues, thus potentially improving the prognosis of myasthenia gravis after thymectomy. We sought to increase efficacy and safety of transsternal maximal thymectomy (TSMT).Materials and MethodsTwenty four patients who underwent TSMT from July 2006 to June 2007 were retrospectively reviewed and compared with 73 patients who underwent transsternal extended thymectomy (TSET) from January 2004 to May 2006. Ectopic thymic tissue in additionally excised cervicomediastinal fat tissue was examined histologically.ResultsIn TSMT group, operation time, amount of cumulative drainage and duration of drainage were significantly higher than TSET group. However, the difference in hemoglobin count, amount of transfusion, duration of intensive care, postoperative hospital stay, and complication rates were not statistically different. There was no operative mortality in either group. Ectopic thymic tissue was found in 50% of patients. All patients had ectopic thymic tissues in the cervical area. Two patients had additional ectopic tissue in the aortopulmonary window, and 1 patient had ectopic tissue at posterior of the left bracheocephalic vein and lateral of the right phrenic nerve.ConclusionTSMT is more effective in the extirpation of ectopic thymic tissues than TSET without significant impairment of safety, especially in the cervical area.

Post-thymectomy combined treatment of prednisone and tacrolimus versus prednisone alone for consolidation of complete stable remission in patients with myasthenia gravis: a non-randomized, non-controlled study

ABSTRACTBackground: Thymectomy is a standard treatment of myasthenia gravis (MG). Immunomodulating agents are frequently given during the post-thymectomy latency period until complete remission is fully consolidated.Objective: A single-centre, non-randomized, non-controlled study was conducted to compare rates of complete stable remission (CSR) to post-thymectomy early treatment with prednisone alone or prednisone combined with tacrolimus, in 80 patients with MG.Methods: Thirty-nine consecutive patients underwent elective transsternal extended thymectomy in 1997–1999 and received prednisone alone (1.5 mg/kg/day) postoperatively, whereas 41 patients operated on in 2000–2002 received prednisone combined with tacrolimus (0.1 mg/kg per day b.i.d. starting 24 hours after thymectomy).Results: The mean follow-up was 59 months (SD 32.9) in the prednisone group and 35.9 months (SD 17.1) in the tacrolimus group ( p = 0.003). CSR was achieved in 47.5% of patients in the tacrolimus group and in 41.0% in the prednisone group ( p = 0.60). The estimated median follow-up to obtain a CSR in non-thymomatous MG was 38.2 months (95% confidence interval [CI] 30.1–46.4 months) for the tacrolimus group and 64.6 months (95% CI 50.9–78.2 months) for the prednisone group, and in patients with hyperplasia, 32.2 months (95% CI 23–41.5 months) and 62.9 months (95% CI 45.7–80.1 months), respectively (log-rank test, p = 0.03). The behavior of the two study groups stratified by thymic histology were significantly different (log-rank test, p = 0.006).Conclusions: Post-thymectomy administration of tacrolimus combined with prednisone was more effective than prednisone alone for the consolidation of CSR in a substantially shorter period of time in patients with MG.

Does perioperative high-dose prednisolone have clinical benefits for generalized myasthenia gravis?

The purpose of this study was to clarify the clinical benefits of perioperative administration of high-dose prednisolone (PSL) combined with extended thymectomy on the long-term outcomes of 116 consecutive patients with generalized myasthenia gravis (MG). A retrospective review was conducted on 116 patients diagnosed with generalized MG who received alternate-day oral administration of high-dose PSL (100 mg/alternate days) and had undergone transsternal extended thymectomy. Incidences of postoperative myasthenic crisis, adverse effects of steroid, long-term outcomes, such as complete stable remission (CSR), pharmacologic remission (PR) or improvement (Imp), and disease recurrence after CSR were evaluated. Six patients (5.2%) experienced post-thymectomy myasthenic crisis. Crude cumulative CSR and PR + CSR rates were 44.8 and 62.7%, respectively. Life table analysis showed that 41.8, 52.8 and 63.4% of the patients were in CSR at 3, 5 and 10 years, respectively. Multivariate analysis revealed that age and pretreatment classification according to the Myasthenia Gravis Foundation of America (MGFA) criteria tended to be independent predictors of CSR. There were 6.9% with compressive vertebral fracture, 13.8% with cataract, and 5.2% with steroid-induced diabetes. Life table analysis revealed that recurrence rates after CSR were 36.8 and 46.0% at 3 and 5 years, respectively. Patients with thymoma had a significantly higher rate of recurrence than those without thymoma (p = 0.001). Alternate-day administration of high-dose prednisolone reduced the risk of post-thymectomy myasthenic crisis. Presence of thymoma was a risk factor for MG recurrence after CSR.

Experience with starting tacrolimus postoperatively after transsternal extended thymectomy in patients with myasthenia gravis

ABSTRACTBackground: Thymectomy is a standard treatment of myasthenia gravis (MG). Immunomodulating agents are frequently given during the postthymectomy latency period until complete remission is fully consolidated, but serious side effects is a relevant clinical problem for patients on long-term immunomodulating treatment.Objective: To assess the effectiveness of starting tacrolimus in the immediate postoperative period in MG patients undergoing transsternal extended thymectomy, with complete stable remission (CSR) as the primary outcome of the study.Methods: Forty-eight MG patients received tacrolimus, 0.1 mg/kg per day b.i.d. (started 24 h after thymectomy) and prednisone 1.5 mg/kg/day. Histologically, 34 patients had hyperplasia, 20 thymic involution, and 14 thymoma. Of the 48 patients, 40 completed 1 year of tacrolimus therapy, 38 completed 2 years, 27 completed 3 years, 21 completed 4 years, and 9 more than 5 years. Mean dose of tacrolimus was 4.9 mg/day (range 2–8 mg/day) with a mean plasma drug concentration of 7.6 ng/mL (range 7–9 ng/mL). Prednisone could be withdrawn after the first year in 93.7% of patients and at 2 years in 100%.Results: The mean follow-up was 24.4 months, SD 17.3 (range 6–60 months). Improvement of muscular strength and decrease of anti-AChR antibodies were statistically significant ( p < 0.001) shortly after operation. CSR was obtained in 33.4% of patients, pharmacological remission in 62.6%; 4% of patients had minimal symptoms. None of the patients with thymoma achieved CSR. The estimated median follow-up to obtain a CSR was 37.9 months (95% confidence interval [CI] 26.4–49.5 months). The overall crude CSR rate was 33.4%, with 47% for non-thymoma patients. The probability to achieve CSR at 3 years was 67% for the non-thymomatous group.Conclusions: Long-term immune-directed treatment with tacrolimus to improve the effectiveness of thymectomy in MG is feasible and was associated with a high rate of CSR in patients without thymoma.