Ureteroscopy

Ureteroscopy (URS) is a minimally invasive procedure used to treat kidney stones and ureteral stones without any external incisions. A thin, flexible scope is passed through the urethra, bladder, and up into the ureter or kidney. Once the stone is located, a holmium or thulium fiber laser fragments it into tiny pieces that are either extracted with a small basket or reduced to fine dust that passes naturally in the urine.

Ureteroscopy offers higher stone-free rates than shock wave lithotripsy (SWL) and is effective for stones of all compositions — including hard stones like calcium oxalate monohydrate and cystine that do not respond well to SWL. It is the most commonly performed surgical procedure for kidney stones in the United States.

Treating Larger Stones Without PCNL

Traditionally, stones larger than 2 cm have been treated with percutaneous nephrolithotomy (PCNL) — an effective procedure, but one that requires a puncture through the back into the kidney and a short hospital stay. Recent advances in ureteroscopic technique now make it possible to achieve excellent stone clearance for many larger stones entirely through the natural urinary passages, avoiding the need for a percutaneous approach.

Dr. Radtke uses two emerging technologies to push the boundaries of what ureteroscopy can accomplish:

SURE (Steerable Ureteroscopic Renal Evacuation) — CVAC

SURE is a minimally invasive technique that combines laser lithotripsy with a vacuum-assisted device to immediately remove stone fragments during ureteroscopy. Dr. Radtke uses the CVAC system — a flexible, steerable catheter inserted through the urinary tract that directly vacuums out stone fragments as the laser breaks them apart. Instead of relying on basketing individual pieces, CVAC provides rapid, direct clearance in real time.

The SURE procedure achieves a 97% stone-free rate, often in a single session, reducing the need for secondary follow-up procedures. It is particularly effective for 1 cm to 2 cm stones and provides faster, more efficient fragment removal compared to traditional basket retrieval — even in complex cases that might otherwise require a more invasive approach.

FANS (Flexible and Navigable Suction Ureteral Access Sheath)

FANS is a specialized ureteral access sheath that integrates continuous suction to significantly improve stone clearance during ureteroscopy. Unlike a conventional access sheath, the FANS sheath features a flexible distal tip that allows better navigation into complex, hard-to-reach renal calyces — particularly the lower pole, where residual fragments most commonly remain after standard ureteroscopy.

By maintaining continuous aspiration, FANS actively evacuates stone fragments and dust as the laser works, reducing the need for manual basket retrieval. This keeps intrarenal pressure low, which in turn reduces the risk of post-operative fever and sepsis. Studies have shown stone-free rates above 90% for stones larger than 2 cm when FANS is used, with reduced operative times compared to conventional techniques.

Together, SURE and FANS represent a shift in how urologists approach larger kidney stones. For appropriately selected patients, these techniques can achieve stone-free rates comparable to PCNL — with the advantages of no incisions, less pain, and a faster recovery.

Is Ureteroscopy with SURE/FANS Right for You?

Not every large stone is best treated with ureteroscopy. The decision depends on stone size, location, number of stones, kidney anatomy, and your overall health. For very large or complex stone burdens (such as complete staghorn calculi), PCNL may still be the best option. Dr. Radtke will review your imaging, discuss the trade-offs of each approach, and recommend the treatment most likely to achieve the best outcome for your specific situation.