Flexible ureterorenoscopy and intrarenal lithotripsy

Operative visualisation

UrOops3D · UroRef · © Nity G

Operative steps

1. Wire up under screening Cystoscopy finds the left orifice at the corner of the trigone, with the image intensifier already over the flank. A 0.035 inch guidewire goes up the orifice soft tip first and its course is read on the screen against each narrowing of the ureter until it reaches the kidney and curls in the collecting system. The wire is the rail for everything that follows, so it is placed under screening, not by feel alone.
   where it bites: a wire forced against resistance dissects or perforates the ureter.
2. Stop there Nothing follows the wire until its curl is seen in the renal pelvis on the screen. The pause is the check that the rail lies in the collecting system rather than submucosally or through a perforation. That first wire stays as the safety wire for the whole case: the rail for a stent if the case has to end early. In the technique this module teaches, the second (working) wire is passed under direct vision through the semirigid ureteroscope into the renal pelvis; the scope comes out over it, and the working wire guides the access sheath. Other routes for the second wire are also in use.
3. Access sheath under screening The suction access sheath, inner dilator in place, is railroaded over the working wire under screening. Length is chosen by sex: about 35 cm for a woman and about 45 to 46 cm for a man (owner-supplied typical values; sizes vary by maker). The tip is watched on the image intensifier the whole way up. It should slide to its mark without force; a sheath that stops is downsized or abandoned, and a ureter that will not accept one is stented and the case rebooked.
   where it bites: forcing a sheath past a narrow, unstented ureter tears the wall or avulses a segment.
4. Suction connected, tip stopped at the renal pelvis The suction tubing is connected to the side port of the sheath, but suction stays off until the tip is in the kidney. On the image intensifier the sheath tip is brought up to the renal pelvis and stopped there, at the PUJ, not pushed through it. A tip seated at the pelvis gives the scope a straight run into the kidney and lets the sheath carry irrigant and fragments out for the rest of the case.
   where it bites: a sheath driven through the PUJ tears the last narrowing.
5. Dilator out, scope in The inner dilator is withdrawn with the working wire, so the working wire is out before lasering, leaving the sheath as the working channel and the safety wire outside it, and the flexible ureteroscope is passed up inside the sheath to the renal pelvis. The scope never meets the ureteric wall: it travels inside the sheath, so every exchange later in the case is low trauma.
6. Map the entire kidney Before the stone is touched, every calyx is inspected in a fixed order: upper, middle, lower. The map is what the case navigates by when the view clouds or a fragment migrates. If the map is complete and every calyx is clear, the next move is straight to the stone and the laser.
7. Contrast, find the stone, move it If the map is not certain, dilute contrast injected through the scope outlines the renal pelvis and all the calyces on the screen, and the stone is found against that picture. A stone in the lower pole is basketed and carried up to the renal pelvis or the upper pole, where the scope is straight, the fibre passes freely and the irrigation works. It is lasered there rather than in the flexed lower pole.
   where it bites: lasering in the fully flexed lower pole strains the scope and the infundibulum.
8. The fibre that will not come out With the tip fully flexed into the lower pole the fibre will not advance out of the channel. It is never forced. The flexion is released, the scope comes back to the renal pelvis, the fibre is advanced out of the channel in the straight scope, and only then is the tip flexed again with the fibre already out.
   where it bites: forcing a fibre round a fully flexed tip breaks the channel or the fibre.
9. Dusting and the settings With the stone where it can be worked, it is dusted at low energy and high frequency, the fibre tip seen on the stone and off the mucosa before every activation, the face painted until the stone is dust the irrigation carries into the sheath. Typical Ho:YAG ranges (owner-supplied):

   Technique	Energy	Frequency	Typical power	Aim
   Dusting	0.2 to 0.5 J	20 to 40 Hz	about 4 to 20 W	Fine particulate, minimal retropulsion
   Fragmentation	0.8 to 1.2 J	6 to 12 Hz	about 5 to 14 W	Discrete basketable fragments
   Pop-dusting	0.3 to 0.5 J	30 to 50 Hz	about 10 to 25 W	Finish fragments in a calyx

   
   where it bites: firing on mucosa rather than stone perforates a thin infundibulum within seconds.
10. Popcorn the tiny fragments The last small fragments are pop-dusted: the fibre is held still just above them in a confined calyx and fired, so the fragments dance in the beam and are reduced without being chased or basketed one by one.
11. Suction clearance to the marker Thumb on the suction port, the access sheath is brought over the scope until the fragments are in view, and the scope is withdrawn slowly all the way down to the marker with the suction running, so the fragments are drawn down the sheath and out. A last look under vision on the way out; a stent only for a marked ureter, oedema or residual dust.

Complications and immediate saves

Trigger each of these live in the Animation tab, then read the save: the first move, the escalation trigger, and the line that goes in the op note.

FRCS viva questions

The examiner stems this scene prepares you for. Try to answer out loud first, then reveal, and learn the discriminator, the detail that turns a pass into a strong pass.

Evidence and guidance