Background:
The exact influence of the Body Mass Index (BMI) on outcome of laparoscopic donor nephrectomy (LDN) is still under debate. We hypothesized that other parameters, such as fat mass, may have a stronger correlation with perioperative complications and short-term results of LDN.

Material and Methods:
A pre-operative imaging review was conducted in a cohort of 620 live kidney donors who underwent LDN between 2004 and 2013. A volumetric measurement of the perirenal fat mass in mm3 was carried out based on CT-scans. Several linear measurements of abdominal visceral fat (IAF-measurements) were performed on both CT and MRI-scans. These data were correlated with several outcome measures of LDN in both univariable and multivariable regression models.

Result:
BMI correlates with some outcome measures of LDN. However, the volume of perirenal fat demonstrates a stronger correlation in even more outcome measures in univariable and multivariable regression: operation duration (p < 0.001), estimated blood loss (p < 0.001), and difference in serum creatinine (p < 0.001) and estimated GFR (p = 0.002) at 1 year postdonation. Furthermore, the IAF measurements show the same significant correlation.

Conclusion:
In this large cohort of live kidney donors, we have confirmed that BMI alone is not the best predictor for outcome of LDN. Importantly, since the IAF is a linear measurement, no complex software is required. Therefore, we conclude that the measurement of intra-abdominal fat is a useful additional parameter in predicting peri- and postoperative outcome of LDN.