Robot-assisted retroperitoneoscopic partial nephrectomy: Comparison of the 3-arm and 4-arm method

Objective: To compare the results from 3-arm and 4-arm robot assisted retroperitoneoscopic partial nephrectomy (RARPN) in our initial case series in terms of oncologic and functional outcomes. Patients and Methods: 35 RARPN performed for malignant small renal masses in our hospital were categorized by the method used, 3-arm or 4-arm. Patient demographics (age, body mass index, tumor size, R.E.N.A.L. nephrometry score, tumor location), perioperative outcomes (operative time, warm ischemic time, estimated blood loss, length of stay, surgical margin status, complications, pathology) and functional outcomes (pre and post operative renal function change) were compared. Results: Initial 14 cases were performed in 3-arm method while latter 21 cases performed in 4-arm method. The tumor size was larger in the 4-arm group (3.5 cm vs 2.3 cm, P = 0.0261) but the warm ischemic time was significant shorter in 4-arm group (17 mins vs 23 mins, P = 0.0093). There were no other significant differences in remaining patient demographics, perioperative outcomes and functional outcomes. Conclusion: 4-arm RARPN is a safe, feasible technique in treating malignant small renal masses even the tumor is located at anterior portion as it provides good traction and exposure on surgical field, thus reducing the warm ischemic time.