- FANS sheath clears stones better than old methods
- Helps patients with medium to large kidney stones
- Available now in select centers, not yet widespread
A new tool could make kidney stone removal faster and more effective.
You wake up after surgery, groggy but relieved. The kidney stone that caused days of agony is gone. But you’re sore. There’s a tube in your back, draining fluid. You’ll need it for days. This is common after a procedure called RIRS—retrograde intrarenal surgery—used to remove stones from the kidney.
But what if you didn’t need that tube? What if the same surgery could clear stones just as well—without the extra pain, the dressing, the recovery hassle?
That future may be here.
Kidney stones affect about 1 in 11 people in the U.S. Many are small and pass on their own. But when stones grow larger—especially between 14 and 27 millimeters—doctors often use RIRS. A thin scope goes up through the ureter to break up and remove the stone.
The problem? Getting everything out safely. Fluid builds up in the kidney during surgery. Without good drainage, pressure rises. That can cause pain, infection, or incomplete stone removal. For years, surgeons used a simple tube called a ureteral access sheath (UAS). It helps, but it doesn’t actively suction.
For tougher cases, some add a percutaneous nephrostomy (PCN)—a tube inserted through the skin into the kidney. It drains well, but it’s invasive. Patients feel more pain. Recovery takes longer.
There’s got to be a better way.
A smarter suction system
Enter FANS—the Flexible and Navigable Suction sheath. It looks like a regular access sheath, but with a hidden feature: built-in suction. It clears fluid and stone fragments as the surgeon works—all from inside the body. No second tube. No puncture through the skin.
Think of it like a vacuum cleaner for the kidney. While the surgeon uses a laser to break the stone into pieces, FANS quietly pulls the debris and fluid out through the same path the scope came in.
It’s like upgrading from a mop to a wet-dry vacuum.
Old tool vs new tools
For years, UAS was the standard. It keeps the ureter open and allows some drainage. But it doesn’t actively pull fluid out. Surgeons often had to stop and restart, waiting for fluid to drain.
PCN solved that. It’s effective. But it’s like building a second door just to carry out trash. Effective? Yes. Efficient? Not really. And it hurts more.
FANS changes the game. It does what PCN does—active drainage—but without the extra hole in the body.
But here’s the catch: no one knew if it actually worked better—until now.
How the study worked
Researchers enrolled 217 adults with kidney stones between 14 and 27 mm—too big to pass on their own. They were randomly assigned to one of three groups: standard UAS, PCN, or FANS.
All had RIRS. Doctors measured how long surgery took, how many patients were completely stone-free afterward, and how many had complications.
The results were clear.
FANS matched PCN in success
The stone-free rate—the gold standard—was highest with FANS: 98.6%. PCN was close behind at 97.2%. But the old UAS? Only 81.9% were stone-free.
That’s a big gap. For every 5 patients using UAS, 1 still had stone fragments left—meaning possible repeat procedures.
Surgery time was shortest with PCN: about 48 minutes. But FANS and UAS both took around 58 minutes. So while FANS cleared more stones, it didn’t speed up the procedure.
Pain and bleeding after surgery were more common with UAS. That surprised some experts. You’d think the group with a tube in their back (PCN) would hurt more. But patients with FANS reported less discomfort than UAS—and almost as little as those without any extra tubes.
Infections and serious complications were rare in all groups.
This doesn’t mean this treatment is available yet.
Kidney stones aren’t just painful—they’re on the rise. More people are getting them due to diet, dehydration, and climate change. Better tools are needed to remove them safely and completely.
FANS offers a real alternative: same success as PCN, without the downsides.
Experts say this study shifts how we think about drainage during kidney surgery. Active suction matters. But you don’t need to go through the back to get it.
“The goal is to do the least harm while doing the most good,” said one urologist not involved in the study. “FANS gets us closer.”
If you’re facing RIRS for a medium to large kidney stone, ask your doctor about FANS. It’s not available everywhere yet. But it’s being used in some advanced centers.
You don’t need to insist on it. But knowing it exists helps. It’s a sign that less invasive, more effective options are arriving.
Don’t panic if your hospital doesn’t offer it. UAS is still safe. PCN works well when needed. But FANS could become the new standard in the next few years.
The study had limits
The trial was strong—but not perfect. It was done at a single center. All surgeons were experienced. Results might not be the same everywhere.
Also, FANS is newer and may cost more. Long-term data is still being collected.
And while recovery looked better, the study didn’t track quality of life in detail after discharge.
More hospitals will begin testing FANS. Larger, multi-center trials are likely underway. If results hold, FANS could replace both UAS and PCN in many cases.
This isn’t a miracle. It’s progress. Steady, smart, and patient-focused.
