Ureteroscopic lithotripsy (URSL) for ureteric calculi

1. Operative Chat
Ureteroscopic Lithotripsy
URSL
Dr. Abhishek Pandey

2. Pre-Treatment Assessment
• Stone Factors –
– Location – Proximal-Mid vs Distal
– Stone Burden – 97% success for ≤1cm; 93% success for >1cm
– Stone Composition – success not affected
• Anatomical Factors –
– Megaureter – Endoureterotomy in <3cm segment → URSL
– Duplicated Collecting System – RGP → URSL
– Ureteral Stricture / Stenosis – Dilatation / Endoureterotomy

3. • Patient Factors –
– UTI – negative culture obtained before procedure
– Renal Function – symptomatic upper tract stones + ≤15% spilt function
consider nephrectomy
– Solitary Kidney – treat asymptomatic stones
– Morbid Obesity – URSL success & safety independent of BMI
– Spine deformity / Limb contracture – Flexible URS
– Coagulopathy – URS + Ho:YAG lithotripsy → Rx of choice
– Duration of obstructing ureteral stone – treat if persistent for 4w

4. Patient & Equipment positioning
• Lithotomy position with liberal padding
• Flexible URS feasible in supine / lateral decubitus positions
• Table should be radiolucent
• Fluoroscopy – Fixed all-in-one table / Portable C-arm unit
• Two irrigation bags – 1 ↓ gravity & 1 in pressure bag
• Laser console as close to surgeon as possible
• Surgeon can sit / stand

6. Guidewires
• Guide to access / dilation / stent placement.
• Diameter – 0.018-0.038 inch – most common 0.038inch
• Length – 80-260 cm – most common 145cm
• Distal tip – Straight / Angled / J-tipped ; floppy for 1-3cm
• Nitinol core wire – kink-resistant & stiffer
• Glide wires – Hydrophilic coated wires instead of PTFE
• Hybrid guidewires – hydrophilic tip & PTFE shaft

7. Ureteral Catheters
• Length usually 70cm with markings at every 5cm.
• Straight tip catheters – 5 or 6 Fr

8. Dilation devices
• Passive dilation – pre-stenting for
≥ 7days before URSL
• Active dilation –
– Dilating catheters – hydrophilic
coated polyurethane tapered
catheters
– Balloon dilator – filled with diluted
radiocontrast

9. Ureteral Access Sheath
• Placed over guidewire under fluoroscopic guidance
• Facilitate flexible URS
• Useful for repeated entries – stone fragment retrieval
• Decrease renal perfusion pressure
• Increase irrigation flow → improve vision
• Inner dilator & outer sheath

10. Ureteroscopes
• Semirigid Ureteroscope
– Larger working channels
– Less prone to damage
– Length – Short (females) or Long (males)
– Tip diameter ≤7Fr
– Eye-piece – in-line / off-set (straight working channel in off-set)
– Working channel – single / double
– Easy to reach till ureter cross iliac vessels

11. Flexible ureteroscopes
• Types –
– Fiberoptic – Fiberoptic bundles carry light & image
– Digital – “Chip on tip” – digital image, ↑ tip diameter
• Deflection mechanism –
– plane of deflection marked by reticle – scope rotated to align the
plane of deflection with the intended target
– Intuitive or counter-intuitive deflection with respect to the lever
• Deflection ≥180° achieved

12. Intracorporeal Lithotriptors
• Pneumatic – requires semirigid URS with a straight working
channel (offset eye-piece) – retropulsion
• EHL – Flexible but more damaging
• Ho:YAG laser – Intraluminal lithotripsy energy of choice –
dusting of stone by photothermal effect

13. Stone retrieval devices
• Three-pronged stone grasping forceps – safest
• Stone baskets – Helical baskets / Flat-wire baskets
• Surgeon should be able to see the endoscope, stone & ureter
during extraction
• Nitinol alloy baskets – memory, maintain shape, resist kinking

14. Retropulsion prevention devices
• prevent migration of distal ureter stones (semirigid URS) into
proximal ureter (flexible URS)

15. Ureteral stents - Drainage
• Double-J (DJ) stents
• Routine stenting has no beneficial effect on stone-free rates
or ureteral stricture rates
• Quality of life better in non-stented patients
• Indwelling-time <14days → fewer adverse effects
• Placing stent for 1-2 weeks after initial unsuccessful URSL
leads to higher success rate of secondary URSL

16. URSL Procedure
• Rigid cystoscopy to identify ureteral orifice
• 5Fr open ended catheter over guidewire → Perform RGP
• Place a safety guidewire up to kidney ↓ fluoroscopic guidance
• If a glidewire is used, replace with stiffer wire
• If pus encountered – send culture, abandon & place a stent
• Drain the bladder before commencing URS
• Intermittent / continuous bladder drainage during procedure

17. Access in narrow ureteral orifice
• Railroad technique – second guidewire passed to tent open
the narrow ureteral orifice ↓ fluoroscopic guidance →
ureteroscope advanced between the wires

18. • Dilation – if access unsuccessful after rail-road technique
• Do NOT dilate over the stone → ureteral trauma, stone
extrusion
• If unsuccessful dilation → 2° URSL after ≥1w stenting

19. Lower Ureteral stones
• Semirigid Ureteroscope
• Ureteral occluding devices used to prevent retropulsion of
calculi into proximal ureter → deployed above the stone
under vision → URS repassed alongside it
• Lithotripsy –
– Dusting – Ho:YAG laser
– Fragmentation → complete basket extraction under direct vision
without using undue force

20. • Laser lithotripsy – activate when tip in contact with stone
– Soft stones – start at 0.2 J & 50 Hz → Dusting
– Hard stones – start at 0.6 J & 6 Hz → gradual fragmentation,
minimising retropulsion
• Inspect ureter after lithotripsy –
– verify stone clearance
– Identify ureteral injury
• RGP at the end of procedure
• Stent may be placed with / without tether

21. Upper Ureteral stones
• Semirigid often not practical in males
• For flexible URS → place 2 guidewires – safety & working
• Pass flexible URS over working wire ↓ fluoroscopic guidance
• Ureteral access sheaths used for high proximal stones →
passed over guidewire ↓ fluoroscopic guidance
• Access sheath should NOT be forced Or passed over the
stone; risk of ureteral trauma & stone extrusion
• If access sheath not passable → proceed without it / stent

22. Complications
• Perforation – 0-4% case
– Splitting after balloon dilation
– Forceful placement of ureteral access sheath
– Placing dilator / access sheath over stone
– Forceful pulling of basket devices
– Direct injury by lithotrites – highest with EHL
– Pressurized irrigation – perforation / calyceal rupture
– Abandon the procedure & place a stent over safety guidewire

23. • Stricture – 3-6%
– Impacted stones
– Ureteral perforation – 6% stricture rates
– Prior ureteral surgery
– Pelvic radiation
– 0.4-4% are asymptomatic
– Recommendation for all patients to undergo postoperative imaging
after ureteroscopic instrumentation

24. • Stone extrusion – 2%
– Submucosal stone – laser excision → ureteral stent
– Complete extrusion / lost stone – in ureteral perforation → abandon &
place stent (do NOT attempt to retrieve the stone)
• Avulsion – 0.06-0.5%
– Forceful manipulation of large / impacted stone
– Avulsion at scope withdrawal (scabbard effect)

25. Thank You