The renal tumor morphological characteristics that affect surgical planning for laparoscopic or open partial nephrectomy.

The purpose of this study is to investigate the morphological characteristics of renal tumors which affect the surgeons' decision-making for the selection of open or laparoscopic partial nephrectomy. We included 147 patients who underwent partial nephrectomy for renal masses with elective indications in this study. Laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) were performed in 72 and 75 patients, respectively. Preoperative trans-sectional images were used to assess tumor characteristics such as tumor size, endophyticity, distance from the sinus, distance from the kidney equator, hilar designation, inside designation, and R.E.N.A.L. nephrometry score. Univariate logistic regression analyses demonstrated that tumor size, endophyticity, distance from the sinus, hilar designation, inside designation, and R.E.N.A.L. nephrometry score were associated with decision of laparoscopic partial nephrectomy. Among these factors, multiple regression analyses showed that endophyticity (odds ratio = 0.92, p = 0.007) and distance from the sinus (odds ratio = 1.201, p < 0.001) had statistically significant associations with the type of operation performed. ROC analyses demonstrated cut-off values of 16 mm for endophyticity (sensitivity 69%, specificity 77%) and of 4 mm for distance from the sinus (sensitivity 79%, specificity 65%) for predicting the selection of laparoscopic surgery. In conclusion, this study revealed that endophyticity and distance from the sinus were important for the surgical planning of partial nephrectomy.