V11-04: Dusting Utilizing Suction Technique (DUST) for Percutaneous Nephrolithotomy: Dedicated Laser Handpiece to Treat a Staghorn Stone
Dusting, use of high frequency and low pulse energy holmium laser settings, is performed during ureteroscopy but reports on this method to treat complex renal calculi via percutaneous nephrolithotomy (PCNL) are limited. We report the first clinical feasibility of a dusting technique during PCNL with the assistance of a specially designed laser suction handpiece (LSHP).
We performed PCNL on a patient with spinal cord injury, urinary tract infection and a computed tomography scan demonstrating a left complete staghorn stone (5x3.5x2.5 cm; 1000 Hounsfield units). Prone PCNL was performed via a 30 Fr Amplatz sheath with access in the lower pole. A 120-Watt holmium laser (P120H, Lumenis) was used as the lithotripsy source to perform Dusting Utilizing a Suction Technique (DUST) for PCNL. A 550um laser fiber was inserted into the LSHP (Lumenis, Israel) which was connected to a suction pump in the P120H. The LSHP weighs 135 grams, and has a stainless steel cannula with an inner lumen diameter of 3.25 mm. Laser fiber length is controlled via a manipulation wheel, with the fiber positioned in a working channel on top of the cannula. Suction is activated on the LSHP, and fragments are sucked into a collection container. We used &[Prime]automatic&[Prime] mode where suction occurred only during laser activation.
We successfully performed DUST-PCNL using settings of 0.6 J x 70 Hz, and 1.0 J x 60 Hz, both on long pulse mode. PCNL took 110 minutes to complete; total lasing time was 21.29 mins, and laser energy usage was 47.68 kJ. The fiber tip was easily visible at the tip of the LSHP, with no failure of the device. We did not encounter any difficulty with fragment aspiration or clogging of the steel cannula or suction tubing. Ancillary devices included a basket to retrieve large fragments, and flexible nephroscopy was performed to dust an upper pole branch of the staghorn. At the end, a 22F Malecot re-entry tube was placed. A nephrostogram on post-operative day (POD) 1 demonstrated a 4 mm residual fragment. Patient was discharged on POD 2. There were no complications; stone analysis demonstrated a struvite stone.
Utilizing a 120-Watt holmium system, we confirmed initial clinical feasibility and safety of DUST-PCNL to perform simultaneous lithotripsy and aspiration for effective stone clearance. An advantage of this method is versatility in treating a stone with both rigid and flexible endoscopy using a lightweight energy source. Further clinical evaluation is needed to understand the efficacy of this technique in comparison to alternate lithotripsy sources.