Association between R.E.N.A.L nephrometry score and perioperative outcomes following open partial nephrectomy under cold ischemia

We investigate the clinical significance of the R.E.N.A.L. nephrometry score for renal neoplasm following open partial nephrectomy (PN) under cold ischemia.Methods: A retrospective analysis was conducted using clinical data of 98 consecutive patients with clear cell renal cell carcinoma who underwent open PN by a single surgeon from December 2000 to September 2012. Tumour complexity was stratified into 3 categories: low (4-6), moderate (7-9) and high (10-12) complexity. Perioperative outcomes, such as complications, cold ischemic time, estimated blood loss and renal function, were analyzed according to the complexity by NS. Complications were stratified using the Clavien-Dindo classification system.Results: Tumour complexity according to nephrometry score was assessed as low in 16 (16.3%), moderate in 48 (49.0%) and high in 34 (34.7%). The median cold ischemic time did not differ significantly among the 3 groups (36.0 minutes in low-, 40 minutes in moderate- and 43 minutes in the high-complexity group, p = 0.421). Total complications did not differ significantly (2 (2.0%) in low, 4 (4.1%) in moderate and 4 (4.1%) in high, p = 0.984). Each Grade 3 complication occurred in the moderate (urine leakage) and high groups (lymphocele). Postoperative renal functional outcomes were similar among the groups (p = 0.729). Only mean estimated blood loss was significantly different with nephrometry score (p = 0.049).Conclusions: The nephrometry score, as used in an open PN series under cold ischemia, was not significantly associated with perioperative outcomes (i.e., ischemia time, complications, renal functional preservation).