A comparison of pathologic outcomes of matched robotic and open partial nephrectomies

Purpose: Open partial nephrectomy (OPN) and robotic partial nephrectomy (RPN) are widely utilized techniques for small renal masses. The lack of tactile feedback and limitations of laparoscopy may result in differences in the surgical specimen that may impact oncologic outcome. We present postoperative pathological outcomes data in a cohort of patients matched for nephrometry score, tumor size, gender and age. Materials and methods: We reviewed 81 patients who underwent partial nephrectomy between January 2003 and March 2010. Twenty-seven underwent RPN and 54 received OPN. Two OPN cases were matched for nephrometry score, tumor size, gender and age for each RPN. Postoperative pathological specimens were reviewed by a urologic pathologist regarding margin status, pathologic stage, histology, renal capsule violation, among other variables. Results: Sixty-two (76.5 %) patients were found to have renal cell carcinoma on final pathology. Frozen sectioning with tumor bed sampling was intra-operatively employed in 70 cases (86.4 %). The overall positive margin occurrence was 1 of 81 patients, which occurred during an RPN for a hilar tumor and converted to radical nephrectomy to achieve negative clinical margins. Additionally, 14.8 % of OPN patients had renal capsule violation as compared to 3.7 % of RPN cases (p = 0.34). Importantly, the mean distance to the proximal margin edge for RPN specimens (2.77 mm) was equivalent to OPN (3.01 mm), p = 0.46. Conclusion: When matched for nephrometry score, tumor size, gender and age, RPN produces similar pathological outcomes to OPN.