I said something like that on a ward round not long ago. The consultant didn’t pull me up on it. Nobody did. But reading through the AUA 2026 Surgical Stone Guidelines recently, I realised I’d been using a term the expert panel has now officially retired.
Clinically Insignificant Residual Fragment
What the Guidelines Changed
The AUA 2026 guidelines have removed CIRFs as a valid reporting category for post-operative stone outcomes. Gone. Not quietly updated.
The problem was that “clinically insignificant” was increasingly being decided on size alone, without thinking about location, composition, or patient risk. The guidelines now want residual burden reported accurately so the decision-maker actually has what they need.
Why the Label Was Always a Bit Off
A 4mm fragment in the lower pole of a single kidney is a different problem from a 4mm fragment in a normal kidney with no metabolic risk factors. Same size, same old label, completely different clinical picture.
The shorthand was skipping the thinking. In stone disease, where recurrence rates are high and some patients are genuinely high-risk, that was starting to cause real problems.
What to Say on the Ward Round
Next time you’re presenting a post-op KUB:
Don’t say: “There’s a CIRF.”
Do say: “There’s a 3mm fragment in the lower pole calyx. No hydronephrosis. Plan to discuss at stone MDT / follow-up / with the consultant re: surveillance vs. further intervention.”
Three things - size, location, context. You’re not being asked to make the decision. You’re being asked to give the consultant the information they need to make it.
The Bigger Picture
Retiring a label sounds like a minor admin update. In practice it’s a push towards honest communication about what surgery actually achieved, rather than what we hoped it achieved.
For a trainee it’s one habit: describe what you see, quantify it, and let the information do the work.