This document discusses flexible ureterorenoscopy (RIRS) for treating conditions of the kidney and urinary tract. RIRS uses flexible instruments introduced through the ureter to access the kidney in a minimally invasive manner. It has advantages over rigid ureteroscopy like shorter hospital stays and recovery time. The document outlines the history, indications, instrumentation, technique and complications of RIRS. Emerging technologies discussed include digital flexible ureteroscopy, flexible robotic assistance and virtual reconstruction of ureteroscopic views.

1. FLEXIBLE
URETERORENOSCOPY
or
RIRS
Gaurav Nahar
DNB Urology Resident
MMHRC

2. INTRODUCTION
• Trend in surgical practice today is towards
developing minimally invasive techniques.
• Endoscopic surgery using minimally
invasive techniques has been the frontier
of medical innovation in last two decades.
• Development of small calibre flexible
instruments permits endoscopic surgery of
urinary tract to treat a wide variety of
lesions/conditions within the kidney.

3. Rising trend for URS...Why???
• Shorter hospital stay
• Lower costs
• Improved cosmesis
• Earlier return to work
• Suboptimal results with ESWL(for renal
stone disease)

4. FLASHBACK...
• 1912: 1st Ureteroscopy by Hugh Hampton
Young ("Father of Modern Urology"); a
rigid 12Fr cystoscope was advanced into
massively dilated ureter of a pt. with PUV.
• Late 1950's: development of first fibreoptic
endoscope.
• 1964: first flexible ureterorenoscopy by
Marshall via a ureterotomy using a 9Fr
flexible endoscope for diagnostic
purposes.

5. • 1977: Goodman & Lyon reported first rigid
ureteroscopy for therapeutic purposes.
• 1990: Fuchs & Fuchs reported the first
large series (208 patients) of renal calculi
treated by flexible ureteroscopy.
• 1998: contemporary RIRS using flexible
ureterorenoscope and Holmium laser for
treatment of renal stones by Grasso &
Chalik.

6. ...the Ureteroscopic "EVOLUTION"
Rigid ureteroscopes with Rod-lens system & outer
diameter 12-13.5Fr & US/EHL probe
↓
Semirigid ureteroscopes containing fibreoptic
illumination & outer diameter miniaturization
↓
Laser & Pneumatic lithotripters
↓
Flexible URS
↓
Digital URS,Robotic URS & Virtual URS(future
trends)

7. RIGID, SEMIRIGID & FLEXIBLE URS

8. FLEXIBLE URS or RIRS: Definition...
• Surgery within the renal pelvicalyceal
system and parenchyma performed using
instruments introduced in retrograde
fashion through the ureter and lower
urinary tract.
• Advantage: more proximal ureter and
intrarenal collecting system more easily
accessible than conventional URS.

9. RIRS: INDICATIONS
DIAGNOSTIC:
• Evaluation of hematuria
• Evaluation of positive upper tract cytology
• Evaluation of radiographic filling defects or
obstruction
• Surveillance after conservative treatment
of upper tract tumors

10. THERAPEUTIC:
Stone Disease:
• Failed ESWL (stones <1.5 cm)
• RIRS assisted ESWL (stones upto 2.5 cm)
• Radiolucent stones (stones <1.5 cm)
• Concomitant renal and ureteral stones (renal stone <1
cm)
• Calyceal diverticular stones
• Stones with nephrocalcinosis
• Stones with associated anatomic obstruction
• Stones with supravesical diversion
• Rarely, partial staghorn stones

11. Others:
• Treatment of PUJ obstruction
• Treatment of anastomotic strictures
• Treatment of urothelial tumors
• Fulguration of bleeding vessels
• Retrograde percutaneous renal puncture

12. RIRS: CONTRAINDICATIONS
• Patients presenting with ‘high-spiking’
fever & rigors, mental status changes, or
other signs of serious infection.
• Better benefit from a PCN.
• Irrigating pressures within ureter during
endoscopy can lead to pyelovenous and/
or pyelolymphatic back-flow, placing the
patient at risk of septicemia.

13. RIRS: SPECIALLY USEFUL
• Urolithiasis m/m in prepubertal children.
• Pregnant females.
• Bleeding diathesis or
Anticoagulant/Antiplatelet therapy.

14. RIRS: INSTRUMENTATION
Instrumentation for RIRS:
1.Newly designed flexible instrument with dual
deflection
2.Energy sources (EHL, Holmium:YAG laser with
small caliber probes)
3.Flexible accessories including guidewires,
dilators, access sheaths, baskets, graspers,
ureteric catheters and forceps
4.Suction pump
5.Video camera unit
6.Fluoroscopy unit

15. FLEXIBLE URETERORENOSCOPE
• Standard fibreoptic flexible
ureterorenoscopes have a tip size in the
range of 6.75 - 9Fr.
• actively deflectable (primary deflection)
with 120 to 170 degrees of deflection in
one direction and 170 to 270 degrees in
other. Secondary deflection will be passive
or active.
• active secondary deflection allows better
manoeuvrability in LC.
• Working channels of Fr 3.6 - 4 and
standard instruments (e.g. baskets) are Fr
2.2 - 3 in size.

17. HOLMIUM: YAG :LASER
• Lithotriptor of choice for RIRS nowadays.
• Wavelength- 2100nm
• Tissue penetration of 0.4mm.
• Laser fibers caliber- 150-220-360-550μm.
• a 550 μm fiber does not allow flexion, and
forcing it may cause Flex URS rupture.
• 150-220 μm fiber allows all degrees of
flexion of Flex URS, with improved
visibility; but fibers are more fragile and
vulnerable to rupture.

18. • Laser energy is delivered via quartz fibres
to stone surface, where it is absorbed and
turned into heat energy that pulverises the
stone into dust by a "photothermal" effect.
• Stone fragment retrieval with basket /
grasping forceps not necessary.
• Can be safely done in anticoagulated pts.

20. DILATORS & ACCESS SHEATHS
• Use of Access sheath optional during
RIRS.
• Depends on surgeon's personal
preference, stone load and PCS anatomy.
• Size of commonly used Access sheaths:
9/11 Fr and 12/14 Fr.
• Serial Teflon dilators up to size 16 used
for ureteral calibration & dilatation before
introducing the Access sheath over guide-
wire under fluoroscopic guidance.

21. Serial Ureteral Dilators

23. Advantages of Access Sheath:
• Facilitate repeated introduction and withdrawal
of endoscope required for large stone burden;
reduces operative time.
• minimizes distal ureteric trauma, wear on the
ureteroscope.
• Avoid build-up of pressure within PCS especially
when pressurised irrigating fluid is used to
improve vision.
Disadvantages of Access Sheath:
• Requirement of pre-stenting 2-4 weeks due to
less spcious ureters.
• Chances of ureteral injury.

24. BASKETS/EXTRACTORS
• Development of tipless Nitinol basket is vital for success
of RIRS of renal stones.
• Tipless design avoids trauma to mucosa during
intrarenal manipulations.
• Also preserve tip deflection of the flexible
ureterorenoscope.
• Relocation of lower pole stones into renal pelvis or upper
pole calyx with basket greatly enhances the efficiency of
stone fragmentation.
• Extraction of stone fragments via Access sheath should
be considered in large stone burden.

26. RIRS: PREOPERATIVE ASSESSMENT
• CT Urogram/IVU to assess stone load, stone
location and pelvi-calyceal anatomy.
• Informed consent.
• Counselling on treatment options, procedure and
potential complications, with possibilities of
requiring postop stenting, second-look
procedure, auxiliary procedure and failed
procedure are all thoroughly explained.
• Preoperative urine cultures.
• General anesthesia & prophylactic induction
antibiotic.

27. RIRS: PATIENT POSITION
• Dorsal lithotomy position.
• Padding of all pressure points.

28. RIRS: TECHNIQUE
Essential points of RIRS technique:
• Safety guide-wire inserted up to renal pelvis;
• Ureteric dilatation and use of Access sheath as preferred
/ indicated;
• Flexible ureterorenoscope "rail-roaded" up to renal pelvis
over double-flexible tips guide-wire under fluoroscopic
and endoscopic guidance;
• Systematic inspection of the pelvi-calyceal system to
identify pathology endoscopically under saline irrigation
(pressurised irrigant as required, preferably with Access
sheath) and aided with fluoroscopy / RP as required;
• Commence lithotripsy with Holmium laser;
• Stone relocation / retrieval with basket as indicated;
• Assess stone clearance with endoscopy/fluoroscopy/RP;
• Placement of double-J ureteric catheter as indicated.

29. • Post-operative ureteric stenting is optional.
• Routine ureteric stenting after uncomplicated
ureteroscopy is not necessary.
• Indications for post-operative ureteric stenting
include
ureteric injury,
ureteric stricture,
solitary kidney,
renal insufficiency and
a large residual stone burden.

30. RIRS: Access to the Upper Urinary
Tract
• Dilation of ureteral orifice
& “optical dilation” with
9.5 Fr rigid ureteroscope.

33. Access to lower pole using secondary
deflection of scope

34. RIRS: SCREENSHOTS...

37. ALGORITHM FOR RENAL STONE
DISEASE

38. RIRS: COMPLICATIONS
Intraoperative complications:
• failure to access (ureter, kidney, or stone),
• stone migration into ureteral wall,
• failure to fragment stone,
• mucosal trauma,
• ureteral perforation,
• devastating complication like ureteral
avulsion due to use of excessive force.

39. Post-operative minor complaints:
• hematuria,
• renal colic (small residual stone
fragments, blood clot),
• pyelonephritis,
• urinoma.
• Ureteral stricture is one of delayed
complication.

40. FOLLOW-UP
• First follow-up visit scheduled about 2
weeks post-op.
• Treatment outcome assessed with a KUB
radio-graph or additional imaging.

41. LIMITATIONS OF RIRS
Technical difficulties due to deficient quality
of instruments used, such as
ureteroscopes offering
• scanty visibility,
• poor illumination,
• a small working channel,
• deficient quality of forceps and baskets,
etc. and
• limited life of instruments with high cost to
Service, especially if used by several
urologists.

42. FUTURE TRENDS...
DIGITAL URS:
• Humphreys MR et al demonstrated the beauty of
digital ureterorenoscopy.
• The distal tip objective is a CMOS imaging
sensor coupled to a prism, utilising light emitting
diodes(LED) as the light source, which gives
superb vision within the PCS.
• Further studies required to show improved
outcome.

44. FLEXIBLE ROBOTIC URS:
• Potential advantages- an increased range
of motion, instrument stability, and
improved ergonomics.
• Avoids excessive strain on the surgeon
who keeps the flexible uretroscope in
deflection for prolonged periods to
approach the target.

46. VIRTUAL URETEROSCOPY:
• Computer driven reconstruction of the
endoscopic view of ureter may prove a
useful noninvasive way of surveilling the
urinary tract.

48. CONCLUSION
• RIRS is an integral part of armamentarium of
urologists.
• A valuable tool both in the treatment of renal
stones refractory to ESWL and also for
diagnosis of upper tract pathology.
• With a refinement of technique, complications
like stricture, perforation and extravasation can
be minimized.
• Future developments of RIRS are digital imaging
to improve the quality of vision and robotics to
improve manoeuvrability.

49. THANK
YOU !!!