[Thymectomy in myasthenia and/or thymoma]

Comparative study of computed tomography of normal and lymphoid follicular hyperplasia thymus in myasthenia gravis patients

The aim of the present study was to evaluate the thymuses of non-thymomatous myasthenia gravis (MG) patients by computed tomography (CT) for differentiating lymphoid follicular hyperplasia (LFH) thymus from normal/involuted thymus in order to assist surgeons in determining whether a non-thymomatous MG patient requires an operation. In the present retrospective review over 10 years, 80 patients who received CT scan and thymectomy at the Affiliated General Hospital of Tianjin Medial University (Tianjin, China) were included. According to the pathological records, 54 of the cases initially detected on CT were confirmed as LFH thymus. Thymic measurements, including anteroposterior and transverse dimensions, width (the longest axis of the lobe on a transverse scan) and thickness (the largest dimension perpendicular to the long axis of the lobe) and CT attenuation of the thymus region, adipose tissue and chest wall musculature in each CT slice were included to assess differences between the LFH group and the normal/involuted thymus group. Although a negative association between patient age and the CT attenuation of the thymus region was identified (r=-0.779, P<0.05, Pearson's correlation test), the LFH thymus group featured nodular changes on CT, while no such changes were observed in the normal/involuted thymus group. The mean age of disease onset in the LFH thymus group was significantly lower than that in the normal thymus group (40.2±17.3 vs. 59.2±9.3 years). Furthermore, significant differences in CT attenuation were identified between the LFH group and the normal/involuted thymus group [-41.21±54.42 vs. -108.23±8.72 Hounsfield units (HU) on unenhanced CT; -25.57±58.65 vs.-117.40±6.22 HU on contrast-enhanced CT]. In the LFH group, the difference in mean CT attenuation between the thymus region and adipose tissue was significant, while no significant difference was observed in the normal/involuted thymus group. In conclusion, CT may be used to distinguish LFH thymus from normal/involuted thymus in MG patients.

The results of video-assisted thoracoscopic thymectomies in Saint Petersburg, Russia: 20-year of experience

BACKGROUND

During the period from 1996 to 2016, we have performed 281 thymectomies in patients with various diseases of the thymus. In 179 patients, thymic pathology was associated with autoimmune myasthenia gravis (MG), and, in 108 patients, thymoma was diagnosed.

METHODS

The majority of surgeries [254] were performed using video thoracoscopy, 79 of them with an additional cervical approach. The long-term results of video thoracoscopic thymectomies in myasthenic patients were followed up for 1 to 15.5 years.

RESULTS

In 26% of the patients, a complete and stable remission was achieved, in 47%-clinical manifestation improved. Local recurrence of thymoma developed in one patient (0.9%).

CONCLUSIONS

Comparison of postoperative complications and long-term results demonstrated that extended video-assisted thoracoscopic thymectomy (VATS-TE) is a radical, efficient, safe, technically feasible and a well-tolerated surgery. It improves the course of MG as a part of multimodality treatment more efficiently than a conservative therapy alone. The course of MG after VATS-TE shows that the cumulative incidence of remissions/improvements reaches its maximum by the 3rd year after the surgery. VATS-TE is radical and safe for removal of noninvasive thymomas up to 8 cm in size. Additional neck incision (VATS-TE + cervical approach) does not provide further advantages, but rather may be a cause of specific postoperative complications.