Skip to main content

The “Omega Sign”: a novel HoLEP technique that improves continence outcomes after enucleation

A Letter to the Editor to this article was published on 20 March 2021



Holmium-laser enucleation of the prostate (HoLEP) has been a promising prostate surgery since its first introduction. Although there are 10 different HoLEP techniques in the literature, stress urinary incontinence (SUI) is common, because surgery is not performed based on the topographic anatomy of the external sphincter. We have developed a new HoLEP method named as the ‘’Omega Sign technique”, which is based on the topographic anatomy of the external sphincter and could provide better continence outcomes by decreasing SUI rates.

Materials and methods

The data of 400 patients who underwent HoLEP by a single surgeon between May 2016 and February 2019 were retrospectively reviewed. The patients were divided into two groups, the first underwent the Gilling’s technique (Group 1) and the second the novel ‘’Omega Sign’’ technique (Group 2). Continence status and post-micturition symptoms (PMS) were evaluated according to the standards recommended by the international continence status.


The data of 400 HoLEP procedures between May 2016 and February 2019 were analyzed, comparing Group 1 (n = 200) and Group 2(n = 200). SUI rate was significantly lower in Group 2 at the day of catheter removal and first month (p < 0.005). In addition, urge urinary incontinence (UUI) rate and PMS were significantly lower in Group 2.


We could demonstrate improved continence results, comparable functional outcomes and equally minimal complications with the standard HoLEP technique. We believe that, the novel ‘Omega sign’ technique decreases SUI rates and will become standardised and easy to understand, thereby bringing and creating a shorter learning curve.

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



Holmium laser enucleation of the prostate


Transurethral prostate resection of the prostate


Open prostatectomy


Benign prostate hyperplasia


Stress urinary incontinence


External sphincter


Body mass index


Prostate specific antigen


Total international prostate symptom scores


Storage international prostate symptom scores


Voiding international prostate symptom scores


Quality of life


Mean maximal urinary flow rate


Postvoid residual urine volume


Operation time


Enucleation efficiency


Hospitalization time


Catheterization removal time


Post-micturition symptoms


International continence status


Low urinary tract symptoms


Urge urinary incontinence


  1. 1.

    Gilling PJ, Cass CB, Cresswell MD et al (1996) Holmium laser resection of the prostate: preliminary results of a new method for the treatment of benign prostatic hyperplasia. Urology 47:48

    CAS  Article  Google Scholar 

  2. 2.

    Fraundorfer MR, Gilling PJ (1998) Holmium:YAG laser enucleation of the prostate combined with mechanical morcellation: preliminary results. Eur Urol 33:69

    CAS  Article  Google Scholar 

  3. 3.

    Saitta G, Becerra JEA, del Álamo JF et al (2019) ‘En Bloc’HoLEP with early apical release in men with benign prostatic hyperplasia. World J Urol 37(11):2451–2458

    Article  Google Scholar 

  4. 4.

    Miernik A, Schoeb DS (2019) “Three horse shoe-like incision” holmium laser enucleation of the prostate: first experience with a novel en bloc technique for anatomic transurethral prostatectomy. World J Urol 37:523

    Article  Google Scholar 

  5. 5.

    Ito T, Tamura K, Otsuka A et al (2019) Development of a complete en-bloc technique with direct bladder neck incision: a newly modified approach for holmium laser enucleation of the prostate. J Endourol 33:835

    Article  Google Scholar 

  6. 6.

    Elmansy H, Hodhod A, Kotb A et al (2019) Top-down holmium laser enucleation of the prostate: technical aspects and early outcomes. Urology 126:236

    Article  Google Scholar 

  7. 7.

    Ahyai SA, Gilling P, Kaplan SA et al (2010) Meta-analysis of functional outcomes and complications following transurethral procedures for lower urinary tract symptoms resulting from benign prostatic enlargement. Eur Urol 58:384

    Article  Google Scholar 

  8. 8.

    Cornu JN, Ahyai S, Bachmann A et al (2015) A systematic review and meta-analysis of functional outcomes and complications following transurethral procedures for lower urinary tract symptoms resulting from benign prostatic obstruction: an update. Eur Urol 67:1066

    Article  Google Scholar 

  9. 9.

    Humphreys MR, Miller NL, Handa SE et al (2008) Holmium laser enucleation of the prostate—outcomes independent of prostate size? J Urol 180:2431

    Article  Google Scholar 

  10. 10.

    Reich O, Gratzke C, Bachmann A et al (2008) Urology Section of the Bavarian Working Group for Quality Assurance†. Morbidity, mortality and early outcome of transurethral resection of the prostate: a prospective multicenter evaluation of 10,654 patients. J Urol 180:246

    Article  Google Scholar 

  11. 11.

    Montorsi F, Naspro R, Salonia A et al (2008) Holmium laser enucleation versus transurethral resection of the prostate: results from a 2-center prospective randomized trial in patients with obstructive benign prostatic hyperplasia. J Urol 179:S87

    PubMed  Google Scholar 

  12. 12.

    Gazel E, Kaya E, Yalcin S et al (2019) Comparison of the efficacy of the prostate in treating prostate volumes of ≤80 and %3e80 mL. Urol Int 102:306

    Article  Google Scholar 

  13. 13.

    Krambeck AE, Handa SE, Lingeman JE (2010) Experience with more than 1,000 holmium laser prostate enucleations for benign prostatic hyperplasia. J Urol 183:1105

    Article  Google Scholar 

  14. 14.

    Kuntz RM, Ahyai S, Lehrich K et al (2004) Transurethral holmium laser enucleation of the prostate versus transurethral electrocautery resection of the prostate: a randomized prospective trial in 200 patients. J Urol 172:1012

    Article  Google Scholar 

  15. 15.

    Bae J, Choo M, Park JH et al (2011) Holmium laser enucleation of prostate for benign prostatic hyperplasia: Seoul National University hospital experience. Int Neurourol J 15:29

    Article  Google Scholar 

  16. 16.

    Gilling PJ, Aho TF, Frampton CM et al (2008) Holmium laser enucleation of the prostate: results at 6 years. Eur Urol 53:744

    Article  Google Scholar 

  17. 17.

    Oh SJ (2019) Current surgical techniques of enucleation in holmium laser enucleation of the prostate. Investig Clin Urol 60:333

    Article  Google Scholar 

  18. 18.

    Endo F, Shiga Y, Minagawa S et al (2010) Anteroposterior dissection HoLEP: a modification to prevent transient stress urinary incontinence. Urology 76:1451

    Article  Google Scholar 

  19. 19.

    Wu Y, Dabhoiwala NF, Hagoort J et al (2018) Architecture of structures in the urogenital triangle of young adult males; comprasion with females. J Anat 233:447

    Article  Google Scholar 

  20. 20.

    Wallner C, Dabhoiwala NF, DeRuiter MC et al (2009) The Anatomical components of urinary continence. Eur Urol 55:932

    Article  Google Scholar 

  21. 21.

    Morgan M, Smith N, Thomas K et al (2009) Is Clavien the new standard for reporting urological complications? BJU Int 104:434

    Article  Google Scholar 

  22. 22.

    Donovan JL, Peters TJ, Abrams P et al (2000) Scoring the short form ICSmaleSF questionnaire. International Continence Society. J Urol 164:1948

    CAS  Article  Google Scholar 

  23. 23.

    Kim M, Lee HE, Oh SJ (2013) : Technical aspects of holmium laser enucleation of the prostate for benign prostatic hyperplasia. Korean J Urol 54:570

    Article  Google Scholar 

  24. 24.

    Scoffone CM, Cracco CM (2016) : The en-bloc no-touch holmium laser enucleation of the prostate (HoLEP) technique. World J Urol 34:1175

    Article  Google Scholar 

  25. 25.

    Gong YG, He DL, Wang MZ et al (2012) Holmium laser enucleation of the prostate: a modified enucleation technique and initial results. J Urol 187:1336

    Article  Google Scholar 

  26. 26.

    Minagawa S, Okada S, Sakamoto H et al (2015) En-bloc technique with anteroposterior dissection holmium laser enucleation of the prostate allows a short operative time and acceptable outcomes. Urology 86:628

    Article  Google Scholar 

  27. 27.

    Takiuchi H, Nakao A, Ihara H et al (2008) Prevention of transient urinary incontinence in peri-operative period of modified holmium laser enucleation of the prostate (HoLEP). Hinyokika Kiyo 54:475

    PubMed  Google Scholar 

  28. 28.

    Naspro R, Suardi N, Salonia A et al (2006) Holmium laser enucleation of the prostate versus open prostatectomy for prostates%3e 70 g: 24-month follow-up. Eur Urol 50:563

    Article  Google Scholar 

  29. 29.

    Sapetti J, Sakat J, Saad E et al (2019) Urinary incontinence after HOLEP: Incidence, evolution and predictive factors. Prog Urol 29:101

    CAS  Article  Google Scholar 

Download references


This study was not funded.

Author information




LT: project development, data analysis, manuscript writing, and management. SY: data collection and manuscript writing. EK: data analysis and manuscript writing. EG: project development and manuscript writing. SY: data collection. HCA: data analysis. MY: data collection. TT: manuscript writing and editing.

Corresponding author

Correspondence to Engin Kaya.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Statement of human rights

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the Helsinki Declaration and its later amendments or comparable ethical standards.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.


Supplementary file1 Supplementary file1 Figure 1 (SM 1): The external urethral sphincter (EUS) and internal urethral sphincter (IUS) in a male foetus (12 weeks of gestation). Three-dimensional reconstruction in (A) anterior view, (B) posterior view, (C) right-lateral view, (D) superior view, and (E) inferior view. The EUS is shown in blue, and the IUS is shown in pink. The urethra and prostate are shown in light grey. Anterior and posterior directions are represented by the letters ‘‘a’’ and ‘‘p.’’ Immunohistochemically stained sections: Sections from inferior (F) to superior (H) stained immunohistochemically for striated muscle, showing the EUS (black arrowheads). Panels (I) through (K) are from same level as sections (F) through (H), stained immunohistochemically for smooth muscle, showing the IUS (red arrowheads). Note the smooth muscle tissue at the dorsal side of the urethra, where the striated muscle of the external sphincter is lacking; see red arrow in (J). Red lines in (C) illustrate the level of the sections as seen in (F) through (H). L = levator ani muscle; PB = pubic bone; R = rectum; U = urethra; bar = 0.5 mm. *This figure was used with special permission of Christian Wallner (Departments of Anatomy and Embryology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands) (TIFF 587 kb)


Supplementary file2 Supplementary file2 Figure 2 (SM2): A1/A2: Bladder neck incisions. B1/B2: Apical incisions. C1/C2: Joining of the bladder neck with the apical incisions bilaterally. D1/D2: Distal end of the anterior incision. E1/E2: Extension of the anterior incision to the bladder neck. F1/F2: Lateral lobe incisions. G1/G2: Final incisions performed just proximally to the verumontanum. H1/H2: Blunt dissection of the median lobe. I1/I2: Complete enucleation of the median lobe adenoma. J1/J2: Pre-prepared initial enucleation of lateral lobes is extended retrogradely to the bladder neck and 2 to 10 o’clock position anteriorly. K1/K2: The lateral lobes are pushed down and separated from the mucosa at 2 o’clock and 10 o’clock positions. Figure 3 (SM-2): Observation of the Omega Sign formed by the preserved mucosa. 3a: retrograde view of the surgical loge from urethra. 3b: Antegrade view of surgical loge from the bladder (TIFF 1884 kb)

Supplementary file3 (DOCX 14 kb)

Supplementary file4 (DOCX 46 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Tunc, L., Yalcin, S., Kaya, E. et al. The “Omega Sign”: a novel HoLEP technique that improves continence outcomes after enucleation. World J Urol 39, 135–141 (2021).

Download citation


  • Holmium laser
  • HoLEP
  • Omega Sign
  • Laser enucleation