Pd16-02 evaluating the Necessity of Routine Post-Operative Labs Following Robotic Assisted Partial Nephrectomy

Abstract

INTRODUCTION AND OBJECTIVE: Radical nephrectomy (RN), with or without resection of the ureter, is the treatment of choice for patients with advanced malignancy of the kidney and/or upper urinary tract. We have previously developed and validated a mortality risk score to stratify postoperative outcomes in patients undergoing radical cystectomy. We hypothesized that this 30-day mortality risk score could be applied to patients undergoing RN for malignancy.METHODS: The National Surgical Quality Improvement Program (NSQIP) identified 16,617 patients that underwent RN for upper urinary tract or renal malignancy from 2013-2017. Patients with complete data were included in the analysis. Risk factors for 30-day mortality were identified on multivariable analysis using backward stepwise binary logistic regression. A previously developed and validated mortality risk score (Figure 1A) was calculated for each RN patient. A receiver operating characteristic (ROC) curve quantified the discriminatory ability of the risk calculator. Statistical significance was defined as p values <0.05.RESULTS: Of 9,345 patients included, laparoscopic/robotic technique was applied in 6,112 (65%) patients. The mean age was 64AE12 years and most patients were male (n[5950, 64%). Postoperative 30-day mortality was 1.2% (n[116). Older age, elevated creatinine, lower albumin and hematocrit, congestive heart failure, exertional dyspnea, >10% weight loss, disseminated cancer, and open surgery as mortality risk factors. After RN, 30-day mortality increased nearly exponentially with escalating risk category (Figure 1B), p<0.00001. The ROC curve for the risk score is shown in Figure 1C; the area under the curve (AUC) was 0.794 (95% CI, 0.755-0.832; p<0.00001). Relative risk of 30-day mortality increased with escalating risk category: moderate risk [4.8 (2.5-9.1, p<0.00001), high risk[16.8 (9.0-31.5, p<0.00001), and extremely high risk [36.8 (13.4-101.2, p<0.00001). The risk score applied to minimally invasive (AUC, 0.785; 95% CI, 0.722-0.849; p<0.00001) and open RN (0.781; 0.730-0.832; p<0.00001).CONCLUSIONS: A previously established mortality risk score can be employed preoperatively in patients undergoing RN for malignancy to stratify 30-day mortality risk. This 30-day mortality risk score is reliable, accurate, and applicable to both minimally invasive and open RN.