Operative note 21 Advanced

Endopyelotomy

What it does: slit a blocked PUJ from inside. (PUJ = where renal pelvis joins the ureter.)

Wire into the kidney. 5Fr catheter over it.
Scope over a 2nd wire. Look before cutting: a pulsing vessel crossing = do not cut there.
Full-thickness SIDE cut, holmium 1-1.5 J.
Balloon the PUJ to 24. Stent ~4 weeks.
Acucise (cutting balloon): contrast in water or glycine, not saline. Markers astride the PUJ. Check with a side view. Balloon 2.2 mL + 75 W cut 3-5 s. Then tamponade.
Percutaneous route (failed surgery, or stones): stones out FIRST. Cold knife hook, under vision. 14/7 endopyelotomy stent, wide end across the PUJ.

2026 update: Rarely first choice now. Lap or robotic pyeloplasty works better: 90-95% vs ~70%.

From the UroRef Operative Quick Guide.