MP31-11: The Geriatric Nutritional Risk Index Predicts Postoperative Complications in Patients Undergoing Radical Nephrectomy for Renal Cancer: A Propensity Score-Matched Analysis

Carlos Riveros*, Victor Chalfant, Ahmed Elshafei, KC Balaji, Jacksonville, FL

Introduction: The Geriatric Nutritional Risk Index (GNRI) is an objective screening tool to predict nutrition-related risk of morbidity and mortality in elderly patients. We assessed whether preoperative GNRI was associated with 30-day complications after radical nephrectomy (RN).

Methods: Using the American College of Surgeons National Surgical Quality Improvement Program database, we identified patients = 65 years old who underwent RN for the treatment of renal cancer between 2006 and 2019. GNRI was calculated using the following formula: [1.489 × serum albumin concentration (g/L)] + [41.7 × present/ideal body weight (kg)]. Based on the original publication describing GNRI, patients were divided into at-risk (GNRI = 98) and no-risk (GNRI > 98) groups. To control for baseline differences, we performed propensity score matching (PSM) using the following covariates: age, sex, race, body mass index (BMI), American Society of Anesthesiology (ASA) score, 5-factor modified frailty index (mFI-5), disseminated cancer, dialysis, dyspnea, use of steroids for a chronic condition, bleeding disorder, smoking history; preoperative anemia, blood transfusion, creatinine, white blood cell count, and platelet count; operative time, and surgical approach (open vs. laparoscopic). Extended length of stay (LOS) was defined as LOS = 75th percentile (=6 days).

Results: We identified 4,994 eligible patients: 1,702 in the at-risk GNRI group and 3,292 in the no-risk GNRI group. Before PSM, patients in the at-risk group were frailer (mFI-5=2: 32.8% vs. 28.3%; p=0.004), had higher ASA scores (ASA>2: 84.2% vs. 74.1%; p<0.001), were more likely to require preoperative dialysis (7.2% vs. 2.9%; p<0.001) and receive preoperative blood transfusion (3.6% vs. 0.5%; p<0.001), and less likely to undergo laparoscopic surgery (56.3% vs. 69.5%; p<0.001). After 1:1 PSM, patients in the at-risk GNRI group had higher rates of urinary tract infection (UTI) (2.8% vs. 1.6%; p=0.037), extended LOS (34% vs. 24.2%; p<0.001), and non-home discharge (19.8% vs. 13.7%; p<0.001). We did not find any significant difference in the rates of surgical site infection, reoperation, or readmission among the two groups.

Conclusions: The present study demonstrates that patients with an at-risk GNRI (=98) are more likely to experience UTI, extended LOS, and non-home discharge after RN for renal cancer. Further research is required to understand whether improving the nutritional status prior to RN can improve postoperative outcomes.

Source of Funding: None