Robot-assisted laparoscopic partial nephrectomy using renal artery cold perfusion for completely intraparenchymal tumors: the outcome and initial experience

Objective To investigate the safety and feasibility of robot-assisted laparoscopic partial nephrectomy using renal artery cold perfusion for completely intraparenchymal tumors. Methods From March 2013 to May 2016, a total of 10 patients underwent robot-assisted laparoscopic partial nephrectomy using renal artery cold perfusion for completely intraparenchymal tumors were analyzed. These included 6 males and 4 female with a mean age of 53 years old( rang from 46 to 70 years old). The average tumor size was 2.8 cm (rang from 2.0 to 4.0 cm). Preoperative CT scan or MRI scan showed the renal tumors were completely endophytic and 3 of them were solitary kidney. The mean R. E.N.A.L. score was 9.8 (rang from 9 to 10). A double lumen balloon-tipped angio-catheter was passed into the renal artery through a femoral puncture preoperatively. The renal artery was occluded by an intraluminal balloon and the renal vein was clipped by Bulldog. Ringer lactate at 4℃ was perfused into kidney drained through the gonadal vein on the left side and through incision of renal vein on the right side, which established a cold ischemia.Intraoperative ultrasound was used to guide tumor enbloc resection with negative margin. Two layers renorrhaphy were performed using 1-0 Quill string and he vessels or collecting system need to be repaired if open. Results All the operations were successfully performed, with a mean operation time of 152 min( rang from 78 to 184 min) and a mean cold ischemia time of 61 min (ranging from 35 to 102 min). The mean estimated blood loss was 265 ml (rang from 100 to 500 ml). The mean postoperative hospital stay was 8.6 days (rang from 4 to 14 days). No positive margin was found. Hematuria occurred in one patient and disappeared three days later. Urinary leakage occurred in one patient and relieved in one week. The pathological diagnosis confirmed 9 clear cell renal cell carcinoma and 1angioleiomyolipoma. The mean preoperative GFR of the affected kidney was 53.9 (rang from 42.3 to 61.9 ml/min). The mean postoperative GFR of the affected kidney 3 moths after surgery was 41.2 (rang from 31.4 to 57.1 ml/min), slightly lower than that before the surgery. No recurrence or metastasis was observed during a median follow-up of 23.5 moths (rang from 3 to 37 moths). Conclusions Robot-assisted laparoscopic partial nephrectomy using renal artery cold perfusion take the advantage of cold ischemia for renal function protecting using renal artery cold perfusion and enhancing surgical visualization and precision of robotic surgery.It is safe and feasible to use this technique for completely endophytic renal tumors. The tumor control and renal function reservation are satisfactory in short term follow-up. However, further investigation with a larger population and longer follow up were required. Key words: Kidney neoplasms; Endophytic renal tumor; Nephron sparing surgery; Renal artery cold perfusion; Robot-assisted laparoscopic technique