[Application of mini-flank open nephron sparing surgery via retroperitoneal route for centrally located renal tumor treatment: a single center experience].

Objective To investigate the safety and feasibility of mini-flank open nephron sparing surgery (MI-OPN) via retroperitoneal route for the treatment of centrally located renal tumor. Methods From May 2013 to April 2015, twenty-four cases of centrally located renal tumor were treated with MI-OPN via retroperitoneal route in Zhongshan Hospital. All cases were included in this study with whose clinical data and long term follow-up information retrospectively analyzed. Results With the assistance of intraoperative ultrasonography to confirm tumor location and boundary, MI-OPN was successfully performed in all cases. Mean tumor maximum diameter was 3.3±0.6 cm, mean operation time was 113±16 minutes, mean ischemia time was 31±6 min, and mean estimated blood loss was 102±46 ml. Mean postoperative hospital stay was 5.0±0.8 days, postoperative complication was found in one patient (4%). The mean pre- and postoperative serum creatinine were 77.1±20.1 μmol/L and 90.3±20.0 μmol/L. Pathological examination confirmed negative surgical margin in all cases, with 18 cases of clear cell renal cell carcinoma, 2 cases of papillary renal cell carcinoma, 2 cases of chromophobe renal carcinoma, 1 case of renal oncocytoma and 1 case of renal angiomyolipoma. In up to 12-36 months postoperative follow-up, no local recurrence or systemic progression was witnessed. Conclusions For the treatment of centrally localized renal tumor, MI-OPN via retroperitoneal route is a safe and feasible operation method. Importantly, rupture of the tumor capsule was effectively avoided during tumor resection with the assistance of ultrasonic position-setting. Furthermore, incidence of severe postoperative complications such as bleeding and damage of collection system were not found since surgical wound of kidney sewn tightly and finely. The last but not the least, by placing ice slush in retroperitoneal cavity, impairment of renal function caused by renal artery clamping can be alleviated due to decreased metabolism. Key words: Nephron sparing surgery; Mini-flank open surgery; Renal tumor