Percutaneous ultrasound-guided renal biopsy in supine antero-lateral position: a new approach for obese and non-obese patients. 
Percutaneous ultrasound (US)-guided renal biopsy is the gold standard in the evaluation of renal diseases, but some patients, such as the obese, may not be eligible for this procedure.  Aim of this study was to determine the feasibility, efficacy and safety of US-guided percutaneous renal biopsy in supine antero-lateral position (SALP) in high-risk patients (BMI > 30 and/or respiratory difficulty), as well as to compare the overall outcome of SALP with that of traditional prone position (PP) in low-risk patients (BMI < or = 30/no respiratory difficulty).  One hundred and ten consecutive patients scheduled for native kidney biopsy were recruited.  Ninety low-risk patients were randomized following a permuted block randomization list to receive either US-guided renal biopsy in PP (Group 1) or SALP (Group 2), whereas 20 high-risk patients received US-guided renal biopsy in SALP (Group 3) and were our observational cohort study.  Comfort compliance and breathing difficulty in each group were evaluated by the Visual Analogue Scale (VAS).  Bleeding complications were evaluated through US renal scanning.  Mean operating time was 7 min.  Comfort compliance and breathing difficulty were significantly better for SALP in both low- and high-risk patients; there were no significant differences in pain after biopsy among the three groups.  Bleeding complications were slightly higher in Group 1.  Diagnostic yield was similar in all groups.  SALP is reliable, minimally invasive, easy, highly successful, timesaving and almost free from severe side-effects.  A better VAS score for breathing difficulty and comfort compliance characterizes this procedure, making it particularly suitable for obese patients.