The experience of robot-assisted thrombectomy in treating renal tumor with Mayo level III to IV inferior vena caval thrombus (report of 5 cases)

Objective To explore the feasibility of robot-assisted laparoscopic inferior vena cava (IVC) thrombectomy in treating renal tumor with Mayo level Ⅲ-Ⅳ inferior vena cava thrombus. Methods From November 2014 to January 2017, 5 cases of renal tumor with Mayo level Ⅲ-Ⅳ inferior vena cava tumor thrombus were treated with robot-assisted surgery. There were 4 males and 1 female with the median age of 59 years (range 54-71 years). Four cases had the renal tumor on the right side and one on the left side. The mean tumor size was 6.8 cm (range 5-9 cm) with 3 cases of T3b and 2 cases of T3c. There were 4 cases of level Ⅲ and 1 case of level Ⅳ inferior vena cava thrombus with the median length of 9 cm (range 7-11 cm). The surgical procedure for Mayo level Ⅲ inferior vena cava thrombus included mobilization of both left and right robes of liver, subsequently controlling the suprahepatic infradiaphramatic IVC and first porta hepatis simultaneously. The surgical procedure for Mayo level Ⅳ inferior vena cava thrombus included cardiopulmonary bypass by multi-disciplinary cooperation among urologists, hepatobiliary and cardiovascular surgeons. The procedures included live mobilization, control of the superior vena cava and first porta hepatis and remove thrombus in the atrium and IVC respectively. Results All operations were completed successfully. The median operative time was 440 min (320-630 min). The blood recovery device was used and the intraoperative estimated blood loss was 2 500 ml (500-6 000 ml) and all cases required intraoperative blood transfusion. The median time of intraoperative occlusion of IVC was 35 min (25- 50 min). All patients were transferred to the intensive care unit for median of 4 days (2-8 days) after surgery. The median time to remove the postoperative drainage tube was 9 days (7-12 days). Postoperative pathological diagnosis revealed 5 cases of clear cell carcinoma. Postoperative renal dysfunction occurred in 3 patients and liver dysfunction occurred in 2 patients who improved after medical therapy. During median 19.6 months (12-48 months) of follow-up, 1 patient died and 1 patient progressed. Conclusions Despite the high risk of surgery, robot-assisted laparoscopic IVC thrombectomy for renal tumor with Mayo level Ⅲ-Ⅳ thrombus is feasible for experienced surgeons in selected patients. However, the oncological outcomes need further investigation. Key words: Kidney neoplasms; Robot; Laparoscopy; Extracorporeal circulation; Multidisciplinary; Inferior vena cava tumor thrombus