Gelman Visualizing Urethral Sound (CS7001)

The Gelman visualizing urethral sound (Cook Medical catalog CS7001) is a hollow, semicircular urethral sound designed by Joel Gelman (UC Irvine Center for Reconstructive Urology) that allows a flexible cystoscope to be advanced through the sound so the tip is placed against the obliterated posterior urethra under direct vision. It is the contemporary replacement for the older solid Haygrove sound in the antegrade-suprapubic step of posterior anastomotic urethroplasty for pelvic-fracture urethral injury (PFUI) and radiation-induced bulbomembranous stenosis.^[1][2]

Design

• Hollow stainless-steel shaft with a full semicircular contour modelled on the Haygrove suprapubic-to-membranous sound.
• Internal lumen sized to admit a flexible cystoscope (e.g., 16–18 Fr scope through the sound).
• Outer diameter is necessarily larger than a solid sound of equivalent inner working channel — the trade-off for adding visualization.
• Cook Medical catalog CS7001 — the most commonly stocked variant.

Why It Exists — The Geometry Problem

Posterior urethroplasty for PFUI / radiation stenosis requires the surgeon to identify the patent normal-caliber urethra proximal to the obliteration after the perineal dissection has transected the distal end. Historical approaches:

1. Antegrade flexible cystoscopy through the suprapubic tract — the most accurate method, but technically difficult in exaggerated lithotomy with a laterally placed SPT, because the scope must traverse a sharp angle through a small-calibre track.
2. Blind passage of a solid Haygrove sound through the SPT to the obliteration — easier mechanically, but the tip placement is by tactile feel only; the surgeon cannot confirm the sound has reached the true proximal urethral lumen vs a false passage in scar.
3. Gelman visualizing sound — combines the mechanical advantage of a semicircular sound (it negotiates the SPT-to-bladder-neck-to-membranous corridor easily) with the visual confirmation of antegrade cystoscopy (the scope inside the sound confirms tip placement at the true proximal urethra).^[2]

Additional advantage: the light from the scope inside the sound transilluminates through the dissection field, helping the perineal surgeon localize the proximal urethral end during sharp dissection.^[2]

Reconstructive-Urology Uses

Posterior Anastomotic Urethroplasty for PFUI

The dominant use. The sequence at the start of a perineal posterior urethroplasty:

1. SPT was placed at least 4 weeks pre-op to mature the tract.^[2]
2. After perineal exposure of the distal stump, the Gelman sound is passed antegrade through the SPT into the bladder, navigated through the bladder neck, and advanced toward the obliterated segment.
3. A flexible cystoscope is passed through the hollow sound's lumen — the operator confirms the tip is at the proximal patent lumen and not in a scarred false passage.
4. The transilluminated tip guides the perineal sharp dissection onto the true proximal lumen.
5. The sound is withdrawn slightly to allow excision of obliterated tissue and creation of a clean spatulated proximal end for the anastomosis.

Radiation-Induced Bulbomembranous Stenosis

The same antegrade visualization workflow is used for post-radiation bulbomembranous urethroplasty. The post-radiation operative field is often more scarred and the planes more obscured than in PFUI, making the direct-vision tip placement particularly valuable. Anastomotic urethroplasty is the preferred technique for radiation-induced bulbomembranous strictures, and recent long-term series report high patient satisfaction with this approach when properly performed.^[3]

Other Reconstructive Uses

• Salvage urethroplasty after failed prior posterior anastomotic repair — even more critical to confirm true lumen vs scar.
• Complex bladder-neck reconstruction with a coexisting obliterated membranous segment.
• Two-stage rendezvous-style urethroplasty when the antegrade-retrograde scope meeting point needs precise localization.

Evidence — Gelman 2015 Series

In Gelman's own institutional series of 76 posterior urethroplasties using the visualizing sound, 0 patients required intraoperative conversion to temporary vesicostomy for inability to identify the proximal lumen, compared to 2 patients in the prior pre-visualizing-sound cohort at the same institution.^[2] The series is single-center observational, but the comparison frames the instrument as a technical-feasibility upgrade rather than an outcome breakthrough.

Gelman Visualizing Sound vs Alternatives for Proximal-Lumen Identification

Approach	Mechanical ease	Visual confirmation	Comment
Gelman visualizing sound + flex scope	Good (semicircular contour through SPT)	Direct vision via scope through lumen	Current standard at high-volume reconstructive centers[1][2]
Solid Haygrove sound	Good (same contour)	None (blind tactile only)	Historical; superseded but still on legacy trays
Antegrade flexible cystoscopy through SPT alone	Poor (sharp angle in exaggerated lithotomy)	Yes	Often defeated by SPT geometry
Retrograde Van Buren from urethral meatus	N/A	Tactile only; cannot reach across obliteration	Not adequate for posterior dissection alone

Technique Pearls

• Mature SPT first — at least 4 weeks of catheter dwell time produces a corridor that admits the sound without fresh-tract bleeding.^[2]
• Match scope size to sound lumen — verify on the back table before incision that the planned flexible cystoscope passes freely.
• Lubricate generously — the larger outer diameter of the hollow sound encounters more frictional resistance through the SPT than a solid Haygrove.
• Coordinate with the perineal surgeon — the antegrade operator advances the sound to where the perineal team needs the tip; the two work together, not sequentially.
• Use the transillumination — dim the OR lights briefly to localize the scope tip through the perineal scar before the next dissection move.

Limitations

• Outer diameter is larger than the equivalent solid sound — passage through a tight or fresh SPT can be harder; mature the tract first.^[2]
• Requires availability of a compatible flexible cystoscope simultaneously; institutions without dedicated reconstructive trays may not stock both.
• Single-vendor instrument (Cook Medical CS7001).
• No randomized data vs solid sound or vs antegrade-scope-alone — evidence base is single-center observational and inference from technical-feasibility metrics.

Historical Context — Joel Gelman

Joel Gelman, MD is Director of the Center for Reconstructive Urology at the University of California, Irvine — one of the most cited contemporary GURS-affiliated reconstructive surgeons in posterior urethroplasty and complex urethral reconstruction. The visualizing sound was developed at his institution and first publicly described as a video / abstract at AUA 2012, with the full technical description published in his 2015 Advances in Urology posterior-urethral-strictures review.^[1][2] Dr. Gelman has also developed the direct-vision balloon dilator (Uromax, Cook Urological / Boston Scientific, 1998) and has publicly declined royalties on both instruments to avoid conflict of interest.

See also: Van Buren Sound, Filiforms and Followers, Balloon Dilator, Suprapubic Catheter, Flexible Cystoscope.

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References

1. Carrillo C, Wisenbaugh ES, Gelman J. "The visualizing urethral sound in posterior urethral reconstruction." J Urol. 2012;187(4S):e3. (AUA 2012 Abstract V06-6) doi:10.1016/j.juro.2012.02.048

2. Gelman J, Wisenbaugh ES. "Posterior urethral strictures." Adv Urol. 2015;2015:628107. doi:10.1155/2015/628107

3. Spilotros M, Mistretta FA, Sahdev V, et al. "Long-term follow-up suggests high satisfaction rates for bulbomembranous radiation-induced urethral stenoses treated with anastomotic urethroplasty." World J Urol. 2023;41(11):3013–3020. doi:10.1007/s00345-023-04429-5