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Semi-Rigid Ureteroscope

The semi-rigid ureteroscope is a straight or gently, passively flexible instrument without active tip deflection, and it is useful for distal and mid-ureteral diagnosis and treatment. Smaller models can reach selected proximal-ureteral lesions, but calyceal survey generally requires a flexible ureteroscope. In reconstruction, it can help assess a suspected injury or stricture and obtain targeted biopsy or treatment when endoscopy changes the plan. Tip, shaft and channel dimensions differ by model rather than defining one universal scope. Dretler and Cho described this instrument family in 1989; small-caliber models followed.[1][2][3][4][16]

Design​

ComponentDetail
OpticsFiberoptic/eyepiece systems are common; lens location, channel geometry and camera coupling are model-specific.
Distal tip and shaftOften tapered, but sizes must be read from the selected product's specification; a narrow tip does not make the wider shaft equally narrow.
Working channelModel-specific; verify the usable instrument diameter and laser/probe compatibility rather than relying on French size alone.
Tip flexibilityPassive bending only; no active calyceal steering lever.
LightUse the manufacturer's compatible light cable and imaging stack.

For example, the current Karl Storz 27000KK lists a 6.5-Fr distal tip, 7–9.9-Fr sheath, 4.8-Fr channel and fiberoptic illumination. A Richard Wolf ultrathin 4.5/6.5-Fr model lists a 3.3-Fr channel. These are distinct models, not interchangeable instrument capacities or full instructions for use.[17][18]

Key design distinction​

  • Passive flexibility, not active deflection. The scope may follow a suitable ureter and occasionally reach the renal pelvis; it cannot reliably steer into or survey calyces.
  • Tapered profile. The narrow tip negotiates the intramural ureter; the larger proximal shaft gives pushability and rigidity for control.
  • Straight working channel in some models. It permits compatible rigid lithotripsy probes; check the selected scope/probe combination.
  • Durability and cost. Semirigid scopes are generally considered more durable than flexible scopes, but local utilization, model and service contracts determine the cost comparison. Gharib's trial measured lower per-patient cost for ultrathin semirigid than for flexible URS in an Egyptian setting.[6]

Reconstructive-Urology and Urogyn Uses​

The semi-rigid ureteroscope is the working tool for distal and mid-ureteral pathology that arises in reconstructive practice.

Iatrogenic ureteral injury after pelvic / urogyn surgery​

  • Intraoperative or postoperative ureteroscopy may help define the location and luminal component of an injury after pelvic surgery. It cannot reliably diagnose devascularization from a normal-looking lumen; integrate operative findings, retrograde imaging and delayed injury assessment.
  • Helps assess whether stenting, drainage or reconstruction is feasible; endoscopic appearance alone does not determine the repair.
  • Allows retrograde guidewire passage and stent placement in continuity injuries.

Ureteral stricture evaluation and endoscopic treatment​

  • Diagnostic mapping of stricture length, location, and luminal characteristics before reconstructive planning (open-ended ureteral catheter plus contrast can complement).
  • Endoscopic dilation or incision may be considered for selected short strictures, with drainage and follow-up. Radiation injury, ischemia, length and prior repair often reduce durability; being radiation-induced is not itself a favorable indication.[3][4]

Upper-tract urothelial tumor​

  • Diagnostic ureteroscopy and biopsy of ureteral tumors during the workup that precedes nephroureterectomy or kidney-sparing endoscopic management.[2][3][4]
  • Endoscopic laser ablation of selected low-risk distal/mid-ureteral lesions after grade, imaging, focality and kidney-sparing goals are considered; follow with early second-look and surveillance if endoscopic management is chosen. EAU 2026 UTUC gives a weak recommendation for second-look ureteroscopy within eight weeks and a strong recommendation to offer kidney-sparing management in low-risk tumors.[19]

Migrated-stent retrieval and foreign-body management​

  • Retrieval of an accessible migrated stent or foreign body, using instruments compatible with the scope.

Stone management (stone is out-of-scope for WARWIKI as a primary topic)​

  • Semirigid URS is commonly used for distal and mid-ureteral stones. In Gharib's randomized 220-patient trial of solitary 1–2 cm proximal ureteral stones, ultrathin semirigid and flexible URS had stone-free rates of 81.9% and 87.8% (p = 0.22); that nonsignificant difference is not proof of equivalence. The lower cost was measured in that study's Egyptian setting, not a universal half-cost rule. Other stone-treatment evidence spans different locations and procedures and should not be pooled into this head-to-head result.[6][8][16]

Technique — Standard Approach​

  1. Position and anesthetic suited to the patient and procedure; fluoroscopic equipment should be available even when a low- or no-fluoroscopy technique is planned.[3][16]
  2. Cystoscopy to identify the ureteral orifice (rigid or flexible).
  3. Safety guidewire (0.035-inch, often hydrophilic Glidewire) into the renal pelvis under fluoroscopy.
  4. Negotiate the orifice gently under vision. Small-caliber scopes often avoid active dilation, but no percentage applies to every ureter. If passage is unsafe, choose a smaller instrument, selective dilation when appropriate, or stent and stage; a UAS is not a routine dilator.[11][16]
  5. Advance under direct vision inspecting the mucosa.
  6. Therapy as indicated. Use a compatible laser fiber or rigid lithotripsy probe, basket, forceps or biopsy instrument. Do not transfer a stone-lithotripsy energy/frequency recipe to ureteral stricture incision or tumor ablation; verify the device instructions, tissue target, irrigation/outflow and thermal risks.[9][16][19]
  7. Inspect for residual fragments and mucosal injury.
  8. Decide on drainage by the observed injury and clinical context. EAU 2026 strongly recommends against a stent after uncomplicated URS (LE 1a); stenting is not routine after an uncomplicated stone URS with complete removal, but is appropriate with trauma, residual fragments, bleeding, perforation, UTI or other concern; an infected obstructed system needs drainage and infection treatment rather than definitive stone work.[10][16]

Smaller Scope = Better — Omar 2022 RCT​

Omar randomized 198 non-obese adults with a first, radiopaque distal or mid-ureteral stone (99 per arm) to 4.5/6 Fr versus 6/7.5 Fr instruments. One-month stone-free status counted residual fragments ≤3 mm on CT; these results are study-specific and do not establish a rule for tumor, stricture or reconstructed ureters.[11]

Outcome4.5/6 Fr6/7.5 Frp
Stone-free rateHigherLower0.004
Balloon dilation needed0%33%0.0001
Traxer grade 1 injury2%14%0.001
Hematuria1%8%0.01
Stent required10%30%0.0004
Failure due to tight ureter0%8%0.003
Hospital stayShorterLonger0.0001

The practical inference is to consider a smaller compatible scope when access is tight, while preserving adequate vision, irrigation and instrument capability.[11]

Semi-Rigid vs Flexible Ureteroscope​

FeatureSemi-rigidFlexible
Distal tipModel-specific, often taperedModel-specific
Active deflectionNonePresent; degree and loaded performance depend on model[5]
Renal-pelvis / calyceal accessSelected proximal/pelvic access possible, but not reliable calyceal surveyDesigned for calyceal access, with anatomical limits
Stone-free comparisonsDepend on stone size/location and follow-up definitionDo not compare unmatched registry percentages as head-to-head evidence
Rigid lithotripsy probesYes (offset-lens models)No
Durability / costMore durable, lower cost / repairMore fragile; single-use emerging
Dilation/UASOften avoidable with small scopesUAS selective, not required in every case

The semi-rigid scope is often efficient for distal/mid-ureteral work; flexible URS is generally needed for calyceal survey. Semi-rigid inspection may precede flexible URS when a distal target or access assessment warrants it, not as an obligatory dilation maneuver.[3][16]

Safety Profile​

  • Ureteral perforation. About 1–8% with standard semi-rigid URS; falls with ultrathin scopes.[2][11][7]
  • Stone / fragment retropulsion, particularly with pneumatic lithotripsy in the proximal ureter.
  • Failure to access. 4–8% with standard scopes; lower with ultrathin.[2][11]
  • Ureteral stricture. The most significant long-term complication:
    • A claims-database association found stricture in 2.9% after URS versus 1.5% after SWL alone (adjusted OR 1.71). This does not prove URS itself caused every excess case; stone severity and selection can confound the comparison.[12]
    • Perforation, impacted stones, prolonged instrumentation and deep wall injury are concerns. Reported risk estimates vary with case selection, injury grading and follow-up; do not use one cohort's odds ratios as patient-specific predictions.[13]
    • In a separate 550-patient cohort, PULS grade-3 transmural injury was followed by stricture in 2/15 (13.3%), compared with 4/550 overall. The reported adjusted odds estimate of roughly 40 is unstable with only two grade-3 events; this is a warning about injury depth, not an individual forecast.[14]
  • Stent-related symptoms. Urgency, frequency, hematuria and flank / pelvic pain are the dominant source of postoperative morbidity when stents are placed.[10]

Practical Pearls​

  • Maintain a safety guidewire throughout (the EAU urolithiasis panel recommends one, while noting that some groups have worked without it); in the post-pelvic-surgery / scarred / radiated ureter, the threshold for retaining the safety wire is lower than in routine endourology (the cost of lost access can mean conversion to open repair). See Guidewires.
  • Never force the scope past resistance. Reassess, use a smaller compatible scope or stage with drainage. Selective dilation requires its own indication and precautions; EAU 2026 describes a JJ stent with return after 7–14 days if access is not possible, and notes that prior rigid URS can provide optical dilation before flexible URS.[16]
  • Pre-stenting is not routine. EAU 2026 states that routine stenting before URS is not necessary; pre-stenting may improve stone-free rates for renal but not ureteral stones (LE 2a). It can facilitate access but causes symptoms, and retrospective studies link longer preoperative stent dwell to postoperative infection. Its text also gives 4.5/6 Fr semirigid scopes as associated with a higher stone-free rate and less ureteral injury than larger scopes, and advises keeping operative time under 90 minutes.[15][16]
  • Antegrade irrigation via an existing percutaneous nephrostomy has been studied for upper-ureteral stone retropulsion, but is not a routine maneuver or a guarantee of prevention.[9]
  • Use flexible URS selectively if proximal/pelvic inspection will answer a clinical question; it is not a compulsory completion step.[3][16]

Limitations​

  • Limited intrarenal access. The proximal ureter or pelvis may be reached in selected anatomy, but calyces generally require a flexible scope.
  • Proximal-ureter results are case-dependent. Gharib's ultrathin-versus-flexible comparison did not show a significant stone-free difference, but was not an equivalence trial.[6]
  • Historical passage figures. Dretler/Cho reported 61% in men and 96% in women with their 1989 instrument; these figures should not be applied to modern small-caliber scopes or individual patients.[1]
  • Retropulsion risk with pneumatic lithotripsy.

See also: Rigid Cystoscope, Flexible Cystoscope, Guidewires, Open-Ended Ureteral Catheters, Double-J Stent, Balloon Dilator.

References​

1. Dretler SP, Cho G. "Semirigid ureteroscopy: a new genre." J Urol. 1989;141(6):1314–6. doi:10.1016/s0022-5347(17)41292-4

2. Ferraro RF, Abraham VE, Cohen TD, Preminger GM. "A new generation of semirigid fiberoptic ureteroscopes." J Endourol. 1999;13(1):35–40. doi:10.1089/end.1999.13.35

3. Giusti G, Proietti S, Rodríguez-Socarrás ME, et al. "Semirigid ureteroscopy: step by step." J Endourol. 2020;34(S1):S13–6. doi:10.1089/end.2018.0286

4. Whitehurst LA, Somani BK. "Semi-rigid ureteroscopy: indications, tips, and tricks." Urolithiasis. 2018;46(1):39–45. doi:10.1007/s00240-017-1025-7

5. Ayyappan KS, Menzies-Wilson R, Jaafari AM, Al-Sattar H, Turney B. "Benchtop comparison of seven ureteroscopes: evaluating physical properties and deflection with flexible and navigable suction access sheaths." BJU Int. 2026;137(Suppl 3):S86–92. doi:10.1111/bju.70124

6. Gharib TM, Abdel-Al I, Elatreisy A, et al. "Evaluation of ultrathin semirigid ureteroscopy in terms of efficiency and cost compared to flexible ureteroscopy in treating proximal ureteric stones: a prospective randomized multicenter study." World J Urol. 2023;41(9):2527–34. doi:10.1007/s00345-023-04507-8

7. Perez Castro E, Osther PJ, Jinga V, et al. "Differences in ureteroscopic stone treatment and outcomes for distal, mid-, proximal, or multiple ureteral locations: the CROES Ureteroscopy Global Study." Eur Urol. 2014;66(1):102–9. doi:10.1016/j.eururo.2014.01.011

8. Matlaga BR, Jansen JP, Meckley LM, Byrne TW, Lingeman JE. "Treatment of ureteral and renal stones: a systematic review and meta-analysis of randomized, controlled trials." J Urol. 2012;188(1):130–7. doi:10.1016/j.juro.2012.02.2569

9. Jung W, Byun HJ, Lee DS. "The role of antegrade irrigation via percutaneous nephrostomy on surgical outcomes in semirigid ureteroscopy among patients with upper ureteral stones." Biomed Res Int. 2019;2019:8657609. doi:10.1155/2019/8657609

10. Ordonez M, Hwang EC, Borofsky M, et al. "Ureteral stent versus no ureteral stent for ureteroscopy in the management of renal and ureteral calculi." Cochrane Database Syst Rev. 2019;2:CD012703. doi:10.1002/14651858.CD012703.pub2

11. Omar M, Dorrah M, Khalifa A, et al. "Randomized comparison of 4.5/6 Fr versus 6/7.5 Fr ureteroscopes for laser lithotripsy of lower/middle ureteral calculi: towards optimization of efficacy and safety of semirigid ureteroscopy." World J Urol. 2022;40(12):3075–81. doi:10.1007/s00345-022-04173-2

12. Sunaryo PL, May PC, Holt SK, et al. "Ureteral strictures following ureteroscopy for kidney stone disease: a population-based assessment." J Urol. 2022;208(6):1268–75. doi:10.1097/JU.0000000000002929

13. Ulvik Ø, Harneshaug JR, Gjengstø P. "Ureteral strictures following ureteroscopic stone treatment." J Endourol. 2021;35(7):985–90. doi:10.1089/end.2020.0421

14. Cumpanas AD, Lavasani SAM, Altamirano-Villarroel J, et al. "Ureteral stricture occurrence after transmural ureteroscopic ureteral injury: a previously undocumented concern." J Endourol. 2025;39(7):679–85. doi:10.1089/end.2024.0702

15. De Coninck V, Keller EX, Rodríguez-Monsalve M, et al. "Systematic review of ureteral access sheaths: facts and myths." BJU Int. 2018;122(6):959–69. doi:10.1111/bju.14389

16. European Association of Urology. EAU Guidelines on Urolithiasis. 2026 (limited update, March 2026). Section 3.4.6, ureteroscopy: best clinical practice, stenting; summary 3.4.6.a.

17. Karl Storz. Ureteroscope 27000KK, current product specification. Model page.

18. Richard Wolf. Ultra Thin Ureterorenoscope, product brochure. 4.5/6.5-Fr model specification.

19. European Association of Urology. EAU Guidelines on Upper Urinary Tract Urothelial Cell Carcinoma. 2026 (limited text update, March 2026). Sections 7.1.2 and 7.1.7, endoscopic ablation and kidney-sparing recommendations.