Extended Corporal Dilation Decreases Need for Adjuvant Maneuvers During Penile Implant Placement in Peyronie's Disease

Upgrading to larger dilators during IPP surgery in Peyronie's disease significantly reduced residual intraoperative curvature and the need for additional corrective steps (P < .01)

Journal: The Journal of Sexual Medicine | Published: 2026-04-09 | Type: Journal Article | PMID: 41967063 Authors: Katlowitz Y, Taniguchi H, Torremade J, Salter CA, Mulhall JP (Sexual & Reproductive Medicine Program, Urology Service, Memorial Sloan Kettering Cancer Center) Funding/COI: NCI NIH HHS; no conflicts of interest listed

Summary

Men with Peyronie's disease who undergo inflatable penile prosthesis (IPP) surgery commonly have residual penile curvature after device placement, often requiring additional intraoperative maneuvers to achieve adequate correction. This single-center retrospective study from Memorial Sloan Kettering compared standard corporal dilation with a Dilamezinsert dilator against extended corporal dilation (ECD) using serial Hegar dilators ≥14 mm in 284 men. ECD produced significantly less residual curvature and required fewer adjuvant procedures, but the urethral perforation rate was statistically higher in the ECD arm.

Claims

• 284 men with Peyronie's disease underwent IPP surgery; 218 (77%) received standard dilation (SD), 66 (23%) received ECD
• Mean baseline curvature was comparable between groups (62 ± 12° overall; P = .76 between arms)
• Mean residual intraoperative curvature for the entire cohort was 24 ± 22°
• ECD produced significantly less post-implant residual curvature than SD (P = .02)
• ECD significantly reduced the need for intraoperative adjuvant maneuvers (P < .01)
• Urethral perforation during manual modeling: <1% (SD) vs 1.5% (ECD); P < .05 — one patient per group

Study Quality

This is a retrospective, single-center cohort study with a historical control design: SD was the standard before 2016, ECD was introduced afterward. That temporal split is the study's central methodological weakness. Any improvement in surgical technique, equipment, case selection, or surgeon experience over that period could partially or wholly explain the outcome differences — the authors do not model or adjust for this. The ECD cohort (n=66) is also substantially smaller than the SD group (n=218), limiting statistical power and the reliability of safety comparisons.

The use of standardized goniometer measurements at both baseline and post-inflation is a genuine methodological strength and distinguishes this from many surgical series that rely on surgeon estimation. Memorial Sloan Kettering is a high-volume specialty center, which improves internal consistency but constrains generalizability to community urology practice.

Red Flags

• Historical controls, not randomized: The pre/post-2016 design cannot exclude temporal confounders — no sensitivity analysis or multivariable adjustment addresses this
• Small ECD cohort: n=66 is underpowered for detecting uncommon complications; the urethral perforation signal deserves a larger dataset before drawing conclusions
• Single-center, specialist setting: Results from a dedicated high-volume program may not transfer to general urology practice
• Urethral perforation rate higher in ECD group: 1.5% vs <1%, statistically significant — the paper acknowledges this in passing but does not discuss clinical consequences or whether the perforation management differed between eras
• No COI disclosure: The paper lists COI as not reported; for a technique study without obvious industry entanglement this may be an oversight, but should be stated explicitly either way
• No long-term follow-up: Intraoperative curvature is a proxy; patient-reported outcomes and device survival are not reported

Strengths

• Standardized pre- and intraoperative goniometry provides objective, reproducible curvature data rather than surgeon estimation
• Both groups had comparable baseline deformity (P = .76), removing severity as an obvious confounder
• Clear protocol definitions for both dilation strategies and a defined threshold (>20°) for triggering adjuvant maneuvers
• NCI/NIH funding rather than device manufacturer support
• Authors are explicit about the study's limitations and appropriately hedge conclusions as "preliminary"

Verdict

The finding is clinically plausible — more aggressive dilation of scarred corpora cavernosa could reasonably reduce residual curvature — and the objective measurement methodology is solid for a retrospective series. But "before 2016 vs after 2016 at one elite center" is a weak design for causal inference, and the statistically significant uptick in urethral perforation in the ECD arm cannot be dismissed as noise at n=66. The authors frame this correctly as preliminary data warranting further study. A prospective randomized comparison at multiple centers is the obvious next step. Until then, this paper is a reasonable hypothesis-generator for surgeons at high-volume Peyronie's programs, not a practice-change document.