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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dilation with a controlled longitudinal cold-knife incision at the 12 o'clock dorsal midline as the device is withdrawn.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when deployed, the blade extends from a longitudinal slot and cuts at the 12 o'clock position as the instrument is withdrawn.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 vs catheter dilation 16% (significant).[5]
  • Nielsen 1989 RCT (n = 200) — no significant difference: urethrotomy + TURP 14% vs TURP alone 21%; the authors concluded that "urethrotomy before TURP cannot prevent postoperative urethral strictures."[6]
  • The practice has largely fallen out of favor with smaller-caliber endoscopic platforms (HoLEP, ThuLEP, bipolar enucleation) that do not require a 28-Fr sheath.[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 (~ 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 – 1970s1973 – present
False-passage riskHigher (blind)Lower (visual)
Calibrated dilation built inYesNo

Outcomes​

  • Frohmüller / Bülow 1975 — Otis urethrotomy in 23 patients; ~ 60% required no further dilations; 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 up to ~ 80% for primary strictures < 2 cm; figures likely transfer roughly to Otis urethrotomy in equivalent anatomy.[9]

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 / local-anesthesia DVIU is possible in selected cases.
  • The Otis remains useful for meatal / 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.[9]

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.

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." 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