Application of R.E.N.A.L.scoring system in robotic laparoscopic partial nephrectomy

Objective To evaluate the clinical value of R.E.N.A.L.scoring system in analyzing the tumor anatomical feature and indication characteristics of patients undergoing robotic laparoscopic partial nephrectomy(RPN).Methods The clinical data of 70consecutive RPN cases done between March 2012and September 2013by the same surgeon at our institutionwere analyzed in this study.The 70patients(47males and 23females)had a mean age of(52.8±10.3)years,a mean body mass index(BMI)of(24.8±3.25)kg/m2,a mean ASA score of 2.0±0.4,and a mean age-weighted Charlson comorbidity index of(0.7±1.03).There were 38cases on the left(with 1case of solitary kidney)and 32cases on the right(also with 1case of solitary kidney).All the tumors were solitary ones,with the maximal diameter being(3.7±1.31)cm and a mean R.E.N.A.L.score of(8.1±1.31).The patients were divided into three groups according to the R.E.N.A.L.scores,and the clinical variables were compared between groups.Results One patient was transferred to open surgery due to intraoperative hemorrhage and the rest were successfully completed.The operative time was(230±48.3)min,estimated blood loss was(154±135.9)mL,renal ischemia time was(23.0±9.30)min,and the mean postoperative hospital stay was(11.4±4.44)days.The overall transfusion rate was 8.57%(6/70)and the complication rate was 17.1%(12/70).Pathological examination revealed no positive surgical margin;there were 58cases with renal carcinoma,4with angiomyolipoma and 8with other benign renal lesions.All patients were alive and had no local recurrence or distant metastasis at the latest follow-up.Nevertheless,the estimated glomerular filtration rate(eGFR)was significantly different before and after operation(P=0.003).Significant differences were also found among the low,moderate and high tumor complexity groups(according to R.E.N.A.L.scores)regarding the cases finished in the first ten cases(50.0% vs 10.9% vs 11.1%,P=0.033),operative time([213±35.5]vs[225±48.9]vs[269±31.7]min,P=0.008),estimated blood loss([86±31.3]vs[158±148.5]vs[172.0±66.7]mL,P=0.032),and renal ischemia time([18.9±7.54]vs[22.2±8.88]vs[30.4±9.76]min,P=0.019).Conclusion R.E.N.A.L.nephrometry score is closely correlated with the surgical outcomes of RPN.Preoperative application of R.E.N.A.L.scoring system to identify tumor complexity can help to guide the clinical use of da Vinci surgical system for partial nephrectomy.