Minimally-Invasive Versus Open Resection For Thymic Neoplasms
Author: Basil Nasir
SUMMARY OF RECOMMENDATIONS
- The surgical approach to thymectomy must adhere to the principles of complete en-bloc resection with an intact capsule. If there is any doubt about achieving this with a minimally invasive procedure, an open or trans-sternal approach should be utilized.
- When performed by experienced surgeons, minimally invasive techniques yield superior short-term outcomes and equivalent long-term results compared to trans-sternal approaches. In these situations, thoracoscopic or robotic-assisted approaches are reasonable alternatives to open or trans-sternal resection
- Given the absence of robust 10-year data, the committee can not make a definitive recommendation regarding the superiority of minimally invasive techniques over trans-sternal and open approaches
- The use of thoracoscopy or robotic-assisted techniques is a reasonable alternative to the open approach. However, we agree with the recommendation against the use of transcervical approaches for resection of thymic neoplasms.
- The committee’s recommendation apply for Masoaka stage I and II thymic neoplasms. Given the lack of data regarding application to more locally advanced disease (Masaoka stage III or IV), the committee can not recommend for or against minimally invasive approaches in these scenarios.
Surgical resection of thymic malignancy should be undertaken whenever possible for localized disease. Several principles must be followed in order to provide the optimal results:
- Surgical resection includes a total thymectomy and complete resection of the lesion and all contiguous and non-contiguous disease with negative margins
- The tumor should be removed intact with every effort to avoid violating the capsule, therefore limiting the possibility of tumor seeding and spreading within the surgical field.
- Complete resection frequently requires excision of adjacent structures, such as pericardium, pleura, lung, phrenic nerve, vena cava, or innominate veins. Resection should be performed en-bloc.
Traditionally, surgical excision of thymic neoplasms has been achieved via a trans-sternal approach, whether via median sternotomy or bilateral thoraco-sternotomy. These approaches continue to be viable options for the treatment of thymic malignancy. However, in recent times, minimally invasive techniques have been adopted and include thoracoscopic transthoracic approaches (right, left, or bilateral), robotic-assisted transthoracic procedures (left or right), subxiphoid approaches, and transcervical approaches.
The committee evaluated the literature and arrived at the following findings :
- The vast majority of studies examining minimally-invasive techniques include patients with Masaoka stage I and II. There are some reports of using minimally-invasive techniques successfully for resection of locally advanced tumors, such as Masaoka stage III. The data supporting this practice is much less robust.
- Minimally-invasive approaches, including thoracoscopic and robotic-assisted procedures, are associated with less intra-operative blood loss, less postoperative morbidity, and shorter hospital length of stay when compared to trans-sternal and open approaches.
- Postoperative mortality is very low in both the minimally invasive and open groups. For many studies, the reported postoperative mortality is 0 in both groups. Because the mortality is so low in both groups, most studies have not demonstrated a benefit regarding postoperative mortality.
- Most studies examining long-term results show equivalent outcomes regarding overall survival, disease progression, and incidences of relapses.
- However, most long-term studies examine data up to 5 years, with little data beyond ten years follow-up. Given the indolent nature of these tumors, 5-year data may be inadequate to draw definite conclusions about long-term results and the superiority of one group over the other.
- There is very little data comparing video-assisted techniques with robotic-assisted techniques. However, the few studies that compare the two techniques have not shown a clear benefit to one over the other. By contrast, transcervical thymectomy has been limited to resection for non-thymomatous myasthenia gravis, with no data showing its safety for resection of thymic malignancy.
- Xie A, Tjahjono R, Phan K, Yan TD. Video-assisted thoracoscopic surgery versus open thymectomy for thymoma: a systematic review. Ann Cardiothorac Surg. 2015;4(6):495-508. doi:10.3978/j.issn.2225-319X.2015.08.01
- O’Sullivan KE, Kreaden US, Hebert AE, Eaton D, Redmond KC. A systematic review of robotic versus open and video assisted thoracoscopic surgery (VATS) approaches for thymectomy. Ann Cardiothorac Surg. 2019;8(2):174-193. doi:10.21037/acs.2019.02.04