Operable Primary Renal Tumors: Pre and Post-operative Volume Evaluation of the Tumor and Rest of the Kidney

The oncological outcome achieved by NSS is considered equivalent to RN in patients with stage T1 renal tumors and as the benefits of NSS become apparent, the indications and application of NSS continue to expand to involve even higher stages of renal tumors, These trails were successful to achieve nearly a similar oncological outcome, however the functional outcome of the residual renal volume was not calculated because most of these studies depend only on the radiographic stage of the tumor. And it is not logic to expose the patients to the risk of NSS surgery with dissection of a large tumor volume to leave only small residual renal tissue volume that may not have enough benefit. To balance this risk benefit ratio, preoperative assessment of expected residual renal tissue volume can be calculated using contrast CT for all patients with renal masses must be done to reach a cutoff point for the least residual volume of renal tissue that should be left postoperatively to achieve a significant function, and to decide whether to do NSS or to proceed to radical surgery from the start.

The technical skill of the surgeon and the anatomical features of the renal tumor are important factors. The contribution of each factor to treatment choice and outcome are particularly relevant because the physician treatment recommendations are subject to training patterns biases, comfort levels and individual experience also the kidney doesn't follow an anatomical partitioning since designation of independent renal segments based on vascular distributions or collecting duct branching is not possible. Nevertheless, renal anatomy does contain consistent and easily reproducible landmarks which can be used by radiologists and surgeons to describe and quantify pertinent features of renal masses therefore Preoperative Aspects and Dimensions Used for an Anatomical Classification (PADUA) scoring system have emerged for quantifying the anatomical features relevant to surgical decision-making and to predict the risk of surgical and medical perioperative complications in renal tumor patients.

1. Preoperative assessment:

2. Using contrast CT radiologist will measure the expected residual renal tissue volume ( total renal tissue volume) and PADUA score.

3. GFR Calculation by Cockcroft-Gault formula.

4. Operative technique:

NSS will be done whenever possible by open approach, according to PADUA score hot ischemia with clamping of the renal artery will be done in less complicated mass while cold ischemia with cooling of the kidney surface after clamping of both renal artery and vein will be done in more complicated masses, Enculation of the mass will be done whenever possible, excision will be done if needed then closure of renal defect will be done only if necessary.