Login to Access Video or Poster Abstract: MP22-03
Sources of Funding: none

Introduction

We prospectively evaluated the feasibility, safety and efficacy of office-based, ultrasound-guided percutaneous renal biopsy (USPRB) of renal cortical neoplasms (RCN).

Methods

Patients with RCN were carefully selected based on tumor location to undergo office-based USPRB. Patients were instructed to apply EMLA cream to a defined area of the flank two hours before the procedure. Procedures were performed in a prone position. After the flank was prepared and draped, facilitated ultrasound targeting (FUT) technology was used to visualize the tumor. After injection of 1% lidocaine, an 18G biopsy needle was inserted through a needle guide on the transducer probe and advanced toward the RCN under US guidance; 3 to 5 cores were taken. US evaluation was then repeated one hour later to assess for hematoma prior to discharge home. We assessed patient pain on a ten-point scale (0 = no pain, 10 = severe pain) before and immediately after the procedure, and at the time of the follow-up, typically one week later. Patient demographics, tumor characteristics, complications, and histopathological diagnosis were recorded.

Results

A total of 40 patients with a mean age of 67 yrs. (range 43-89 yrs.) underwent renal biopsy. There were 21 (53.5%) males and 19 (46.5%) females. The mean tumor size was 3.6cm (range 1.6 - 6.3). The mean R.E.N.A.L. nephrometry score was 6 (4-12). Thirty two (80%) of the 40 biopsies were diagnostic. Diagnostic biopsies included 21 (52.5%) renal cell cancer and 11 (27.5%) patients with benign histopathology (7 oncocytomas and 4 angiomyolipomas). The patients with benign histopathology elected active surveillance. There were no complications during or after the biopsy procedure. None of the patients reported pain before the procedure. Median pain score immediately after the procedure was 1/10(0-3) and 0/10(0-5) at one hour after the procedure and 0 at three-week follow-up (p=0.657, 0=1.433). Based on histopathology (benign and indolent RCC sub-type), surgical intervention was averted in 42.5% of patients. Among the 8 patients with a non-diagnostic biopsy, all underwent a repeat CT guided biopsy. Of these, 4 were RCC subtypes and 1 remained non-diagnostic.

Conclusions

Urologist performed office-based, US guided renal biopsy of selected renal cortical neoplasms is feasible, safe and precludes surgical therapy in one fourth of patients.

Funding

none