V6-02: Ultrasound Guided Percutaneous Renal Access
Still a minority of urologists in the United States performs their own renal access during percutaneous nephrolithotomy, with many relying on interventional radiology to obtain access. When urologist do obtain their own access, most utilize fluoroscopic image techniques. Fluoroscopic techniques have limitations in use including the risks of increasing radiation exposure and the lack of identification of surrounding structures around the kidney. In this video we demonstrate techniques for obtaining ultrasound guided percutaneous renal access and give technical tips and tricks to perform this procedure.
Ultrasound-guided access is obtained using a convex ultrasound probe at 3.5-5 MHz depending on the calyceal depth and body habitus of the patient. The abdomen is scanned on linear and axial projections to visualize surrounding structures including liver, bowel, pleura and diaphragmatic reflection. Once the desired calyx is identified, the needle guide is aimed at the calyx and the anesthesiologist holds respirations. The needle is visualized in real time entering the intended calyx. The stylet is removed and urine should be seen flowing out.
Ultrasound guided percutaneous renal access has several advantages over fluoroscopic guidance: it is readily available, portable and inexpensive; provides guidance for access in multiple planes and allows for real time monitoring of the tip of the needle and with the use of doppler flow it allows avoidance of large vascular structures.
Ultrasound guided access to the kidney may improve safety, versatility and cost while reducing the risk of radiation exposure. We demonstrated some practical tips to improve ultrasound-guided access and hope that more urologists will get convinced on the advantages of this technique during percutaneous renal surgery.