Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Correspondence
  • Published:

On the validity of metrics for defining penile distensibility phenotypes

International Journal of Impotence Research volume 30, pages 361–363 (2018)Cite this article

Subjects

Yafi and colleagues’ recent report [1] on the grower/shower phenomenon is noteworthy for examining a concept that has arguably received disproportionately little scientific attention in comparison with its lay recognition. As Shindel has noted [2], their results are unfortunately limited by their choice of metric in quantifying penile expansion, though I believe the implications are substantially more serious. As I shall demonstrate, their analysis is both conceptually and quantitatively incompatible with their clinical question, and distorts the relationship of their results to the literature.

The framework for quantifying penile expansion is of central importance, and I agree with the authors’ justification of erect rather than stretched length as germane to the conceptual grower/shower distinction. However, full explication of the phenotypes reveals that they must be characterized by a measure of relative rather than absolute expansion. This accords with the authors’ invocation of relativity in their general definitions and their stated intent to “quantify relative penile length expansion” [1]. In the current study, however, the authors defined grower/shower phenotypes by comparing individual absolute length increases to the group median absolute length increase of 4.0 cm. This choice fails to capture relativity in quantifying individual expansion, and indeed the essence of the phenotypes.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1

References

  1. Yafi FA, Alzweri L, McCaslin IR, Libby RP, Sangkum P, Sikka SC, et al. Grower or shower? Predictors of change in penile length from the flaccid to erect state. Int J Impot Res. 2018. https://doi.org/10.1038/s41443-018-0053-3

  2. Shindel AW. Growers versus showers: a meaningful (or useful) distinction? Int J Impot Res. 2018. doi: 0.1038/s41443-018-0070-2

  3. Udelson D, Nehra A, Hatzichristou DG, Azadzoi K, Moreland RB, Krane J, et al. Engineering analysis of penile hemodynamic and structural-dynamic relationships: Part I—clinical implications of penile tissue mechanical properties. Int J Impot Res. 1998;10:15–24. https://doi.org/10.1038/sj.ijir.3900310

    Article  CAS  PubMed  Google Scholar 

  4. Wessells H, Lue TF, McAninch JW. Penile length in the flaccid and erect states: guidelines for penile augmentation. J Urol. 1996;156:995–7. https://doi.org/10.1016/S0022-5347(01)65682-9

    Article  CAS  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA

    Patrick S. Phelan

Authors
  1. Patrick S. Phelan
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Patrick S. Phelan.

Ethics declarations

Conflict of interest

The author declares that he has no conflict of interest.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Phelan, P.S. On the validity of metrics for defining penile distensibility phenotypes. Int J Impot Res 30, 361–363 (2018). https://doi.org/10.1038/s41443-018-0078-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41443-018-0078-7

Search

Advanced search

Quick links