Management of high complexity renal masses in partial nephrectomy: A multicenter analysis.

OBJECTIVE: To determine the safety and efficacy of performing partial nephrectomy (PN) on patients with high nephrometry score tumors.

PATIENTS AND METHODS: We used a prospectively maintained multi-institutional kidney cancer database to identify 144 patients with R.E.N.A.L. nephrometry score ≥10 who underwent PN for a cT1-cT2 renal mass. Baseline demographics and clinical characteristics, tumor characteristics, perioperative, and pathological outcomes were analyzed and reported. Trifecta achievement, defined by warm ischemia time <25 minutes, no perioperative complications, and negative surgical margins, was the primary outcome. We assessed the relationship of baseline clinical and tumor characteristics data to trifecta achievement and perioperative complications.

RESULTS: Baseline median eGFR was 84.57 ml/min/1.73 m2 , with 119 (84.39%) patients having normal baseline kidney function. The median clinical tumor size was 4.95 cm, with 74 (51.75%) being completely endophytic and 58 (41.73%) located on the hilum. The median ischemia time was 20 minutes. Median estimated blood loss was 150 ml. Twelve patients (8.33%) had intraoperative complications. No patient had a conversion to open surgery. Postoperative, perioperative, and major complication rate were 10.42%, 17.3%, and 2.34% respectively. Thirty-six patients (37.89%) developed postoperative acute kidney injury and 28 (20.90%) developed new-onset CKD at a median follow-up of 6 months. Eight patients (5.56%) had a positive surgical margin. Trifecta was achieved in 89 (61.81%) patients. There was no significant difference in baseline, clinical, and tumor characteristics between those that achieved trifecta and in those where trifecta was not. Pathologic tumor stage was the only factor significantly associated with trifecta achievement (P = 0.025).

CONCLUSION: In treating complex renal tumors, PN should be performed when possible. Although this remains a challenging procedure, with experience and appropriate case selection, the trifecta outcome can be achieved in a significant number of patients with high renal score lesions.