Number of Renal Columns Invaded by Tumor: A Novel Parameter for Predicting Complexity and Outcomes of Off-Clamp Open Partial Nephrectomy

The number of renal columns invaded by tumor is a novel, intuitive, and practical parameter that could be used to quantify renal tumor complexity and predict the risk of perioperative outcomes after off-clamp OPN. Specifically, NRC correlates with estimated blood loss, operative time, surgical complications, renal function, and conversion to on-clamp. In the future, NRC can be integrated with other parameters, such as tumor location, to assemble a new scoring system.