Background: In the US, native kidney biopsies are usually inpatient procedures. We developed an outpatient biopsy protocol for low-risk patients and assessed its safety and efficacy. Methods: Patients with an SBP <140 mm Hg and a BMI ≤35 who were not taking anticoagulants, ASA and NSAIDS in the preceding week were included. Biopsies were performed under ultrasound guidance using a 15-gauge needle that changed to a 14-gauge needle during the study. Patients were discharged after 5 h of observation if there were no signs of bleeding. Complications were carefully recorded. Results: Between November 2008 and April 2011, 105 patients underwent outpatient renal biopsies. A 15-gauge needle was used in 43 patients (group A) while a 14-gauge needle was used in 62 (group B). A median of 25 (range 4–64) glomeruli were obtained in group A versus 39 (range 0–107) in group B (p < 0.001). Complications requiring admission for observation occurred in 7 patients (16%) in group A versus 5 patients (8%) in group B (p = 0.22). One patient in group B had bleeding requiring intervention, while all other complications were minor. Nine complications occurred during the observation period, while 3 patients presented >48 h after biopsy. The mean cost per patient for each outpatient biopsy was USD 976 versus USD 5,489 for inpatients. Conclusions: In a selected low-risk population, outpatient renal biopsy is safe with low complication rates and results in significant cost savings relative to elective inpatient biopsies. The use of a 14-gauge biopsy needle resulted in a greater yield of glomeruli without increased complications.

Background and objectives Age and body mass index (BMI) of kidney donors and recipients affect kidney allograft outcomes. Moreover, while deceased donor and recipient body size mismatch have been reported to influence allograft outcomes, how BMI mismatch in living kidney donor–recipient pairs affect graft survival is not well defined. Design, setting, participants, and measurements We investigated trends in characteristics of 90,815 US. living kidney donors and their recipients between 1987 and 2008. Results Median ages of donors and their recipients have risen over time, and the proportion of living donors age ≥50 years increased from 11 to 25%. Median BMI of recipients increased from 22.6 to 26.6 kg/m2; median BMI of kidney donors for the past 5 years has been 26.4 kg/m2. Only 35% of living donor-recipient pairs were in the same BMI category (<25, 25–29.9, 30–34.9, or ≥35kg/m2). BMI mismatch where the living donor was three categories heavier than the recipient was associated with a significant adjusted risk for death-censored allograft loss (HR 2.31, 95% CI 1.05–5.08). Conclusions Living kidney donors are donating at more advanced ages, and the majority are overweight or obese in recent years. In summary: (1) previous longitudinal studies of living kidney donor outcomes may not be generalizable to recent donors, and studies of contemporary living kidney donor cohorts may be informative, (2) the majority of living donor–recipient pairs have BMI mismatch, and (3) extreme BMI mismatch where the living donor is heavier may confer an independent risk for allograft loss.