Thymic carcinoid tumors are usually associated with MEN-1 [1,2]. Thymic carcinoid tumors are rarer than thymomas, have a poor prognosis, and have a characteristic tendency to recur and metastasize years after the initial diagnosis and treatment. The effect of chemotherapy is unknown, but in most cases, initial surgical intervention and radiotherapy seem to help.
RATS is gaining popularity due to the many benefits offered by robotic surgical systems. As a result, RATS procedures have seen a rapid increase in Japan. The dedicated robotic instruments of the robotic surgical system are capable of motions with 7 degrees of freedom under three-dimensional view. Even in a mediastinum packed with intertwined organs, the robotic surgery system can execute surgical maneuvers smoothly and naturally [5]. RATS have gained importance for MT surgeries and have been shown to achieve results comparable to those of the video-assisted thoracoscopic surgical (VATS) approach or open surgery. Furthermore, excellent perioperative outcomes of robotic resections of malignant tumors in the anterior mediastinum have been reported [4]. Conventionally, in MT resection by RATS, a skin incision is made at each port insertion site placed strategically to avoid robotic arm collisions. In this procedure, the left and right forceps operations were moved vertically with the endoscope in between.
Ishikawa et al. [6] reported a completely endoscopic single port robotic surgery. In their procedure, a robotic endoscope and two robotic instruments were inserted through one port about 2.5-cm long at the third intercostal space on the right anterior chest. However, although they attempted pneumothorax by CO2 insufflation to maintain a sufficient distance from the tumor, they were unable to maintain an airtight environment. Their technique of employing cross-arm technology was useful in safely preventing collisions and achieved good clinical and excellent cosmetic results. Since the mediastinum is a tightly packed organ with a narrow space, the working space of robotic instruments needs to be expanded. Thus, CO2 insufflation is helpful in expanding the working space, and our technique makes this step easy. Subsequently, the robotic instruments were operated the same as in a normal RATS operation without using cross-arm technology.
This study has some important limitations: First, although some authors agree on the use of aggressive attempts similar to the approach for thymoma, in this case, a part of the thymic and pericardial fat including the tumor was resected. Second, the indication of this single-incision total port RATS may be controversial. This procedure may require extensive experience of RATS when manipulating a wide range of operative fields such as thymectomy or when removing larger tumors. Furthermore, skilled surgeons may have been able to perform the surgery via uniport VATS. Nevertheless, the procedure outlined in this report is feasible, easy to perform, and provides dexterity during the procedure. Furthermore, since a new robotic surgery system via a single port has already been reported, this procedure may be easier to perform.
This report demonstrates that thymic carcinoid tumor removal is feasible and easy to perform via single-incision port RATS. Since the mediastinum is a tightly packed organ with a narrow surgical field, CO2 insufflation was performed, and an airtight environment was maintained by inserting ports into three different intercostal spaces through wound protectors. Our case thus provides further confirmation that robotic-assisted surgical systems can be successfully used for surgical intervention in MTs, given the complete resection, and uneventful postoperative course achieved in this case.