Long-term renal outcomes in obese patients after minimally invasive vs. open partial nephrectomy for the treatment of renal cancer – A retrospective study (Preprint)

BACKGROUND Obesity has a significant association with renal cell carcinoma (RCC). Surgery is the preferred treatment of demarcated RCC. Obesity increases the complexity of surgical outcomes. There is a paucity of data regarding surgical technique outcomes in obese patients. OBJECTIVE We investigated short- and long-term renal outcomes in obese patients post-RCC surgery through open, laparoscopic, or robotic partial nephrectomy. METHODS This is a retrospective chart review of obese patients after open, laparoscopic, or robotic partial-nephrectomies over 12 years at a single center. The obese (BMI ≥ 30) and the non-obese (BMI< 30) patients were studied in 2-time frames: short (3-6 months post-surgery), or long (> 6 months) and followed up to 4 years. RESULTS Of the 140 patients, 75 were obese and 65 were non-obese. In the obese, 3-6 months after minimally-invasive surgery, the odds of having a decrease or no change in creatinine values were 0.62 times lower compared to open surgery. Over 6 months after minimally-invasive surgery, the odds were 1.24 times higher. Neither of these results were statistically significant. In the non-obese group, at 3-6 months after minimally-invasive surgery, the same odds were 4.86 times higher. This was statistically significant (P<0.05). Over 6 months after minimally invasive surgery, the odds were 4.13 times higher. This was not statistically significant. CONCLUSIONS We observed non-statistically significant preservation of renal function in obese patients undergoing OPN at 3-6 months postoperatively. Conversely, after 6 months, the same was true for MIPN, indicating a long-term benefit of MIPN. In the non-obese, MIPN was favored over OPN. CLINICALTRIAL na