Installation scheme. A, Supine position. First (B, C) and second (D, E) port placement. Red arrow, camera axis.
Central Message.
We present an alternative for thymic resection with two-step docking. This strategy allows for better visualization of both phrenic nerves, with a rotated viewpoint enabling extensive resection.
Technique
The patient is placed supine with the arms alongside the body and a bolster under the xiphoid area to open the thoracoabdominal angle (Figure 1), We use a 4-arm technique, including Maryland bipolar forceps on the right arm and fenestrated grasping bipolar forceps and Prograsp forceps on the left arm.
Figure 1.
Operating view of the upper anterior mediastinum during second docking.
The procedure begins with a first docking lateral approach on the side of the tumor under one-lung ventilation. As in a conventional robotic lateral approach,1 the camera port is inserted at the fifth intercostal space along the anterior axillary line, and two 8-mm ports are inserted at the third intercostal space along the anterior axillary line and on the parasternal space at the fifth intercostal space. CO2 is insufflated at 10 L/minute with a pressure of 7 to 12 mm Hg. The Da Vinci surgical system is docked from the lateral side.
The pleura is opened, and the thymus is separated from the anterior border of the phrenic nerve and from the pericardium if possible; otherwise, the pericardium is resected. The thymus and mediastinal fat are detached from the sternal edge from the embouchement of the internal mammary vein to the cardiophrenic fat. The subxiphoid port placement site is prepared by detaching the perithymic tissue from the xiphoid process and the diaphragm. Dissection continues retrosternally until the contralateral pleural space is widely opened (Video 1). Double-lung ventilation is applied with reduced volumes and increased frequency. Under visual control, an 8-mm port is inserted at the fifth contralateral intercostal space along the anterior axillary line, a vertical incision is made in the subxiphoid area, the linea alba is dissected, and an 8-mm retrosternal port is inserted.
For the second docking, the robotic arms are switched, with the camera inserted via the subxiphoid port, Maryland bipolar forceps on the right arm, and fenestrated grasping bipolar forceps on the left arm. A Prograsp forceps is positioned on the tumor side.
On the opposite side, mediastinal fat and thymic tissues are laterally detached from the embouchement of the internal mammary vein to the cardiophrenic fat. Both phrenic nerves are now visible and are carefully dissected. The innominate vein is cleared, and the thymic veins are transected. The superior poles of the thymus are detached, and thymectomy is completed (Figure 2). The specimen is retrieved through the subxiphoid incision (Figure 2).
Figure 2.
Gross surgical specimen showing compartmental resection of the anterior mediastinum, including the thymic tumor, both entire lobes of the thymus, mediastinal pleura, and associated fatty tissue.
The linea alba fasciotomy is closed to prevent herniation, and redon drains are placed in both pleural spaces before closing supported by Valsalva maneuver.
Discussion
Thymectomy, including the tumor, residual thymus gland, and perithymic fat with en bloc resection of adjacent invaded organs, is the recommended curative treatment for resectable thymic tumors.2 Although median sternotomy remains the gold standard, minimally invasive thymectomy offers comparable outcomes for small tumors.3
However, owing to the thymus's central position, the unique perspective offered by most minimally invasive approaches limits complete visualization of the operative field and may require blind maneuvers, particularly concerning dissection of the contralateral phrenic nerve. Some experts accept performing partial thymectomy in well-encapsulated tumors to avoid neurologic damage. For larger tumors and myasthenia gravis, it appears necessary to develop minimally invasive techniques that approach the clarity offered by median sternotomy.
Our approach combines subxiphoid4 and lateral approaches with advantages for robotic thymectomy, allowing rotation around the thymus. The first setting allows precise dissection of the ipsilateral phrenic nerve, cardiophrenic fat, lower poles of the thymus, and low-located tumors without a predocking thoracoscopic procedure or blind dissection. The second setting allows an interesting rotated viewpoint, comparable to sternotomy with a clear view of both phrenic nerves, upper poles, innominate vein, and the neck region, which can reduce the risk of nerve injury. This allows anterior mediastinal lymph node dissection, ectopic tissue removal, and compartmental surgery with en bloc resection of mediastinal and cardiophrenic fat, bilateral mediastinal pleura, and the pericardium if necessary. This technique is an approach of choice in cases of large tumor or myasthenia, because it allows extensive resection.
The thymoma is located between the robotic arms, enabling precise manipulation and avoiding blind grasping and capsule disruption. In large tumors, the robotic arms work efficiently with enough space; moreover, retrieval may be easier via a subxiphoid incision without affecting pathologic observation. However, a bilateral thoracic incision may cause additional pain, and attention must be given to subxiphoid wound closure to prevent linea alba hernia. Exposure can be influenced by anatomy and positioning. The angle between the sternum and the abdomen must be open, and thus the presence of pectus excavatum or abdominal obesity may compromise this approach.
Conflict of Interest Statement
M.G. is proctoring for Intuitive Surgical, Inc. The other authors reported no conflicts of interest.
The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.
Footnotes
Written patient informed consent was obtained. Institutional Review Board approval was not required.
Supplementary Data
Thymectomy, including the tumor, residual thymus gland, and perithymic fat with en bloc resection of adjacent invaded organs, is the recommended curative treatment for resectable thymic tumors. Although median sternotomy remains the gold standard, minimally invasive thymectomy offers comparable outcomes for small tumors. Our approach combines the advantages of subxiphoid thymectomy with lateral exposure. Video available at: https://www.jtcvs.org/article/S2666-2507(24)00342-0/fulltext.
References
- 1.Wei B., Cerfolio R. Robotic thymectomy. J Vis Surg. 2016;2:136. doi: 10.21037/jovs.2016.07.17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Girard N., Ruffini E., Marx A., Faivre-Finn C., Peters S. Thymic epithelial tumours: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2015;26:v40–v55. doi: 10.1093/annonc/mdv277. [DOI] [PubMed] [Google Scholar]
- 3.Kang C.H., Na K.J., Park S., Park I.K., Kim Y.T. Long-term outcomes of robotic thymectomy in patients with thymic epithelial tumors. Ann Thorac Surg. 2021;112(2):430–435. doi: 10.1016/j.athoracsur.2020.09.018. [DOI] [PubMed] [Google Scholar]
- 4.Suda T. Robotic subxiphoid thymectomy. J Vis Surg. 2016;2:118. doi: 10.21037/jovs.2016.07.02. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Thymectomy, including the tumor, residual thymus gland, and perithymic fat with en bloc resection of adjacent invaded organs, is the recommended curative treatment for resectable thymic tumors. Although median sternotomy remains the gold standard, minimally invasive thymectomy offers comparable outcomes for small tumors. Our approach combines the advantages of subxiphoid thymectomy with lateral exposure. Video available at: https://www.jtcvs.org/article/S2666-2507(24)00342-0/fulltext.