Artificial reconstruction for a thymoma invading superior vena cava

A 63-year-old woman presented to the hospital with cough and chest tightness. A chest computed tomography examination revealed a right anterior mediastinal mass of approximately 8 cm × 5.5 cm in size, invading the SVC (Figure 1, A). The pathology using core needle biopsy diagnosed a World Health Organization type B2 thymoma. The patient was then referred to the mediastinal multidisciplinary diagnosis and treatment center at our hospital, and received a treatment strategy of surgical resection after induction chemoradiotherapy. The protocols of induction chemoradiotherapy (Figure 1, A and B) were developed by experienced radiologists and oncologists in the multidisciplinary diagnosis and treatment team. Soon the patient received 3 cycles of chemotherapy with paclitaxel liposome 60 mg day 1 and cisplatin 40 mg day 1, and intensity-modulated radiation therapy with a prescription dose of 56 Gy in 28 fractions over a 6-week period. The patient was reassessed after chemoradiotherapy. Although the thymoma had regressed, it had not achieved the expected therapeutic purpose for surgical resection. After a 2-month recovery period, the patient received an additional 2 cycles of standard chemotherapy with paclitaxel liposome 240 mg day 1 and cisplatin 120 mg day 1 over a 2-month period (Figure 1, B and C). The thymoma was significantly regressed and underwent a complete surgical resection (Figure 1, C and D). The Zhongshan Hospital Research Ethics Committee approved the study protocol and publication of data (B2021-454; June 28, 2021). The patient provided informed written consent for the publication of the study data.

The details of the surgical procedure are presented in Video 1. Briefly, median sternotomy was performed to access the chest cavity, mobilize the thymus (Figure 2, A), open the pericardium, fully expose the right auricle, and dissect the left innominate vein (Figure 2, B). Heparin with 1 mg/kg was given for anticoagulation, and a polytetrafluoroethylene artificial vessel with a 10-mm diameter was anastomosed to the distal end of the left innominate vein (Figure 2, C). The other end of the artificial vessel was anastomosed to right auricle (Figure 2, D). Then the SVC, right innominate vein, and azygos vein were transected (respectively, Figure 2, E, F, and G). The right upper lung tissue invaded by the thymoma was dissected (Figure 2, H) and the specimen was finally removed (Figure 2, I and J).

The operation time was 185 minutes and the intraoperative blood loss was 300 mL. No complications occurred in the perioperative period. The duration of chest tube was 9 days, and the hospital stay after surgery was 10 days. Oral rivaroxaban, 10 mg once daily, was used for long-term postoperative anticoagulation. By the follow-up date, it had been 12 months since the surgery, and no tumor recurrence was detected, and the artificial vessel was patent (Figure 1, E).

SVC resection and reconstruction might be the best treatment for SVC syndrome. However, SVC reconstruction is a challenging procedure that requires a detailed preoperative assessment of the vascular situation and a skilled vascular anastomosis technique. We recommend a surgical strategy of SVC reconstruction followed by extended resection of the thymoma because we believe that completion of SVC reconstruction avoids complete blockage of the SVC and facilitates the subsequent tumor resection procedure. In this case we performed a single artificial vessel from the left innominate vein to the right auricle for SVC reconstruction, and no complications due to the artificial vessel were detected during the follow-up of up to 12 months. Therefore, a single artificial vessel might be sufficient for SVC reconstruction in some cases.

Many materials, such as bovine pericardial conduit and artificial synthetic materials, have been used to create artificial vessels for SVC reconstruction,^, each with its own advantages and disadvantages. The choice of artificial vascular material should be determined according to the patient's condition and the situation of the surgical center. An artificial blood vessel made of biomaterials that does not require long-term anticoagulation might be a better option. Although we still adopt a conservative long-term anticoagulation because of concerns about postoperative embolic complications, the strategy of long-term anticoagulation after SVC reconstruction is still controversial and needs to be addressed in the future.

Finally, it is worth noting that when performing tumor resection, care should be taken to block the SVC first to prevent embolism caused by tumor thrombus shedding in the SVC. Care should also be taken to protect the left phrenic nerve to avoid causing bilateral phrenic nerve injury. In conclusion, extended resection of thymoma combined with SVC resection and reconstruction can be used to treat patients with thymoma with SVC syndrome.