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Otis Urethrotome

Blind (non-visual) internal-urethrotomy instrument that combines calibrated dilation with a controlled longitudinal cold-knife incision at the 12 o'clock dorsal midline as the device is withdrawn. The historical predecessor to direct-vision internal urethrotomy (DVIU); now largely supplanted by the Sachse direct-vision urethrotome but retaining a niche role in meatal / fossa-navicularis stricture and in resource-limited settings. Named for Fessenden Nott Otis (1825–1900), the American urologist who is also the namesake of the Otis Bougie-à-Boule. The ICS male LUTS-surgery terminology document explicitly defines blind urethrotomy as "opening of the stricture with the use of a special instrument (Otis urethrotome) to perform the incision without direct visualization."[1]

Design​

  • Long slender metal shaft introduced per urethra with the blade retracted and the expandable segment collapsed.
  • Calibrated expandable distal segment. Turning a screw on the handle widens the segment to a precise French diameter shown on a graduated handle scale, allowing measured dilation before the cut.
  • Concealed retractable cold-knife blade housed within the shaft; when deployed, the blade extends from a longitudinal slot and cuts at the 12 o'clock position as the instrument is withdrawn.
  • Handle carries the expansion screw, blade-deployment mechanism, and the French-gauge scale.
  • Stainless steel, fully autoclavable.

The two functions in one instrument, dilate-then-incise on withdrawal, distinguish the Otis from both a plain sound (no cut) and the Sachse / Collins-knife systems (cut under vision, no calibrated dilation).

Reconstructive-Urology Uses​

Stricture incision (historical and niche)​

  • Meatal and fossa-navicularis strictures. The short straight distal urethra is the safest anatomy for a blind dorsal-midline cut; the Otis retains a small role here when DVIU equipment is not at hand.
  • Resource-limited settings. When an endoscopic urethrotome and irrigation system are unavailable.
  • Bulbar strictures. Historically managed with the Otis; modern practice uses DVIU instead.

Prophylactic urethrotomy before TURP (historical)​

The Otis was widely used as a preliminary cut at the meatus and distal urethra before TURP to accommodate the 24–28 Fr resectoscope sheath and reduce post-TURP stricture rates.

  • Schultz 1989 RCT (n = 185). Otis urethrotomy before TURP 4% stricture versus catheter dilation 16% (significant).[5]
  • Nielsen 1989 RCT (n = 200). No significant difference: urethrotomy plus TURP 14% versus TURP alone 21%; the authors concluded that "urethrotomy before TURP cannot prevent postoperative urethral strictures."[6]
  • Routine preliminary urethrotomy is no longer standard. The 2026 EAU guideline notes that only one of these comparative studies reported at least 12 months of follow-up, and it found no significant difference in stricture rate (21% versus 14%).[10] Stricture incidence also appears lower after enucleation than after TURP.[7]

For procedural context, see DVIU and Urethral Dilation.

Technique — Otis Method​

  1. General or regional anesthesia. The blind dilation component is more painful than a visual urethrotomy under local.[3]
  2. Insertion with blade retracted and segment collapsed.
  3. Advancement past the stricture. If too tight, preliminary filiform-and-follower or sound dilation.
  4. Expansion. Turn the screw to widen the segment to the target caliber (approximately 28–30 Fr in the adult male).
  5. Blade deployment and slow withdrawal. The blade makes a clean dorsal-midline longitudinal cut as the expanded segment is pulled back through the stricture.
  6. Foley catheter 18–22 Fr placed at the end of the case.[2][3]

Otis vs Sachse (DVIU)​

FeatureOtis (blind)Sachse (DVIU)
VisualizationNone — blindDirect endoscopic vision
MechanismExpand → blade cuts on withdrawalCold-knife incision under vision
Incision controlCuts at 12 o'clock through whatever tissue is thereSurgeon selects site / depth under vision
Stricture traversalMust pass instrument through / past stricture firstCan incise progressively from proximal to distal
AnesthesiaGenerally GA / regionalOften local in select cases
Era of predominanceLate 1800s – 1970s1974 – present
False-passage riskHigher (blind)Lower (visual)
Calibrated dilation built inYesNo

Outcomes​

  • Frohmüller / Bülow 1975. Otis urethrotomy in 23 patients; approximately 60% required no further dilations; the authors reported a low complication rate.[2]
  • Hjortrup 1983. 72 consecutive patients over 5 years; success 82% (95% CI 71–90%) at mean 29-month follow-up.[3]
  • Cochrane (Wong 2012). The only RCT directly comparing dilation to urethrotomy used the Sachse technique, not the Otis; head-to-head data between Otis and Sachse remain sparse.[4]
  • AUA 2023. Dilation and DVIU are interchangeable first-line options for short bulbar strictures, with the highest success rates in bulbar strictures < 1 cm; success falls rapidly with length, recurrence, penile location, and ischemic etiology.[8]
  • Verla 2019 review. DVIU success reaches up to approximately 80% for primary strictures < 1 cm, with the best results in primary strictures < 1.5 cm.[9] These figures describe cold-knife DVIU, not the Otis, and are given for comparison.

Safety Profile​

  • False passage. The principal complication of the blind technique; the rationale for the modern shift to DVIU.[1][3]
  • Uncontrolled incision depth. The 12 o'clock cut goes through whatever tissue is at the blade; in pendulous urethra this risks corporal-tunica injury.
  • Urethral hemorrhage, UTI, bacteremia. Standard urethral-instrumentation risks.
  • Stricture recurrence. The underlying biology (re-fibrosis) is not changed by switching from blind to visual incision; recurrence remains the principal limitation of any endoscopic stricture management.

Limitations and Modern Positioning​

The Otis has been supplanted by the Sachse DVIU for the great majority of indications because:[3][4]

  • Direct vision spares healthy mucosa and limits false-passage risk.
  • Progressive incision from proximal to distal eliminates the need to traverse the stricture first.
  • Office or local-anesthesia DVIU is possible in selected cases.
  • The Otis remains useful for meatal or fossa-navicularis strictures and in equipment-limited settings.

Historical Significance​

The Otis urethrotome was one of the first instruments to move stricture management beyond simple dilation toward controlled incision. Otis's principle, that a measured, calibrated longitudinal cut heals across to a wider lumen rather than tearing scar, is the conceptual ancestor of modern DVIU and remains the foundation of endoscopic stricture management today.

See also: Otis Bougie-à-Boule, Van Buren Sound, Filiforms & Followers, Balloon Dilator, S-Shaped Coaxial Dilators, DVIU and Urethral Dilation.

References​

1. Abranches-Monteiro L, Hamid R, D'Ancona C, et al. "The International Continence Society (ICS) report on the terminology for male lower urinary tract surgery." Neurourol Urodyn. 2020;39(8):2072–88. doi:10.1002/nau.24509

2. Frohmüller H, Bülow H. "Use of the Otis urethrotome in the treatment of urethral strictures and congenital urethral stenoses." Eur Urol. 1975;1(2):87–90. PMID 1233173

3. Hjortrup A, Sørensen C, Sanders S, Moesgaard F, Kirkegaard P. "Strictures of the male urethra treated by the Otis method." J Urol. 1983;130(5):903–4. doi:10.1016/s0022-5347(17)51565-7

4. Wong SS, Aboumarzouk OM, Narahari R, O'Riordan A, Pickard R. "Simple urethral dilatation, endoscopic urethrotomy, and urethroplasty for urethral stricture disease in adult men." Cochrane Database Syst Rev. 2012;12:CD006934. doi:10.1002/14651858.CD006934.pub3

5. Schultz A, Bay-Nielsen H, Bilde T, et al. "Prevention of urethral stricture formation after transurethral resection of the prostate: a controlled randomized study of Otis urethrotomy versus urethral dilation and the use of the polytetrafluoroethylene coated versus the uninsulated metal sheath." J Urol. 1989;141(1):73–5. doi:10.1016/s0022-5347(17)40592-1

6. Nielsen KK, Kjoergaard B, Kristensen ES, Jeppesen L, Krarup T. "Does internal urethrotomy prevent urethral stricture after transurethral prostatectomy? Early and late results." Eur Urol. 1989;16(4):258–61. doi:10.1159/000471587

7. Vanthoor J, Herrmann TRW, De Coninck V. "Can preoperative transurethral catheterization reduce the risk of urethral stricture after endoscopic treatment of the prostate?" World J Urol. 2025;43(1):325. doi:10.1007/s00345-025-05474-y

8. Wessells H, Morey A, Souter L, Rahimi L, Vanni A. "Urethral stricture disease guideline amendment (2023)." J Urol. 2023;210(1):64–71. doi:10.1097/JU.0000000000003482

9. Verla W, Oosterlinck W, Spinoit AF, Waterloos M. "A comprehensive review emphasizing anatomy, etiology, diagnosis, and treatment of male urethral stricture disease." Biomed Res Int. 2019;2019:9046430. doi:10.1155/2019/9046430

10. Campos-Juanatey F, Barratt R, Chan G, et al. "European Association of Urology guidelines on urethral strictures: summary of the 2026 guidelines. Update in recommendations for endoluminal management of male anterior urethral strictures." Eur Urol. 2026. doi:10.1016/j.eururo.2026.04.021