US-guided Nephrostomy with the Aid of a Magnetic Field-based Navigation Device in the Porcine Pelvicaliceal System

Purpose: To assess the technique and feasibility of ultrasound (US)-guided nephrostomy performed with the aid of a magnetic field-based navigation device.

Materials And Methods: Twelve percutaneous nephrostomy procedures were performed in seven domestic pigs under real-time US guidance employing a navigation system. Two magnetic field sensors registered the actual position of the puncture needle and the US transducer. The actual needle position and the aimed puncture tract were graphically projected into the real-time US images, allowing exact navigation of the needle. After placement of the needle into the renal pelvis, the nephrostomy tube was inserted by means of the Seldinger technique.

Results: The puncture procedure was successfully performed in each case. The renal pelvis was punctured in a single attempt in 10 of 12 cases. In two cases, multiple attempts were necessary because bending of the puncture needle led to inaccuracies of the navigation system. With exception of two small perirenal urinomas, no complications were seen.

Conclusions: The magnetic field-based navigation device allows easy and accurate performance of nephrostomy guided solely by US.