Ligamentous structures in human glans penis

Glans cap-preserving dorsal inlay-free graft augmentation technique for reconstruction of meatal stenosis and fossa navicularis strictures: Analysis of short-term functional outcomes

Introduction

Meatal stenosis and fossa navicularis strictures (FNSs) are commonly caused by lichen sclerosus and instrumentation. We present the technique and short-term functional outcomes of glans cap-preserving dorsal inlay-free graft augmentation for the reconstruction of meatal stenosis and FNS.

Methods

This retrospective study analyzed patients with meatal stenosis and FNS who underwent glans cap-preserving dorsal inlay-free graft augmentation at our institute since 2019. The surgical technique included a ventral subcoronal approach, preservation and mobilization of the glans cap, a ventral midline urethrotomy incision over the stricture, and a dorsal midline meatotomy incision extending to the proximal normal urethral mucosa at the fossa navicularis, followed by dorsal inlay graft augmentation. During the follow-up, patients were periodically assessed for symptom scores, urinary flow rates (UFRs), and patient-reported outcomes.

Results

A total of 26 patients with a mean age of 45 ± 15 years were assessed. The predominant cause of stricture was lichen sclerosus (n = 15; 58%). The mean stricture length was 3.8 ± 0.5 cm, 73% had a circumcised phallus, and an oral mucosa graft augmentation was performed in 22 (85%) patients. Notable postoperative complications included intractable meatal hemorrhage (n = 1) and glans suture granuloma (n = 1), which required intervention. At a mean follow-up of 40 months, there were four failures, of which one patient required redo-urethroplasty. The remaining patients (n = 22; 85%) showed improved symptom scores (P < 0.05), UFRs (P < 0.05), and satisfactory patient-reported outcomes.

Conclusion

Glans cap-preserving dorsal inlay-free graft augmentation is a safe and feasible technique with satisfactory short-term functional outcomes for the management of meatal stenosis and FNS in carefully selected patients.

Glans penis volume is associated with lifelong premature ejaculation

BACKGROUND

Although premature ejaculation (PE) is the most common male sexual dysfunction, the underlying mechanisms are not fully understood.

AIM

The study sought to evaluate the possible associations among glans penis volume and tissue stiffness measured using penile ultrasonography and penile shear wave elastography (SWE) with PE.

METHODS

Men 18 to 65 years of age with normal International Index of Erectile Function scores (>25) and who were diagnosed with PE between June 2021 and June 2022 were enrolled. The Premature Ejaculation Diagnostic Tool score and intravaginal ejaculation latency times were recorded. Healthy volunteers constituted the control group. The study group was divided into lifelong PE (LLPE) and acquired PE (AqPE) subgroups. In all groups, the glans penis volume was measured via penile ultrasonography and tissue stiffness of the glans penis, penile frenulum, postcircumcision mucosal cuff, and penile shaft were measured via SWE. The findings of the groups were compared using appropriate statistical methods.

OUTCOMES

The outcomes included ultrasonographic and elastographic measurements of the glans penis.

RESULTS

Data on 140 men, including 70 PE patients and 70 healthy volunteers, were evaluated. Of the patients, 20 had LLPE and 50 had AqPE. The median glans penis volume was significantly greater in the LLPE group (14.1 [range, 6.6-19] mm3) compared with the AqPE group (11.7 [range, 5.1-27] mm3) and control group (11.4 [range, 6.1-32] mm3) (P = .03). According to the Youden index, the best cutoff value for glans penis volume in LLPE compared with non-LLPE (AqPE + control) was 12.65 mm3 (area under the curve, 0.684; 95% confidence interval, 0.556-0.812; P = .009). The risk of having LLPE in those with a glans penis volume ≥12.65 mm3 was 3.326 (95% confidence interval, 1.234-8.965) times higher than the non-LLPE group (P = .014). There were no significant differences between the groups in the SWE evaluation of glans penis, penile frenulum, mucosal cuff, and penile shaft tissue stiffness.

CLINICAL IMPLICATIONS

The high incidence of PE in those with high glans penis volume may make glans penis volume a predictor for the development of LLPE.

STRENGTHS AND LIMITATIONS

This was the first study to show that PE is more common in individuals with a high glans penis volume. It was also the first to perform a penile elastographic evaluation in patients with PE. The most important limitation was that we did not evaluate glans penile nerve function with a test, but rather we made an indirect inference about the density of free nerve endings based on increased glans penile volume.

CONCLUSION

Glans penis volume was a significant predictor for LLPE. However, there are no associations between PE and the glans penis, postcircumcision mucosal cuff, penile frenulum, or penile shaft tissue stiffness and development.

"Fossa navicularis" and "septum glandis": A "flow-control chamber" for the male urethra?

A clear understanding of the normal anatomy of the glanular urethra is essential for anatomical reconstruction of the male urethra. In hypospadias surgery, tubularization of the neourethra over a catheter or stent has been the standard method for decades. However, the male urethra is not a tubular structure with uniform configuration and diameter by forming a fossa (navicularis) in the glans penis. We recently investigated the structural anatomy of the glanular urethra using magnetic resonance imaging (MRI). We have shown that the male urethra does not have a uniform tubular structure and not covered by the corpus spongiosum to the end. The glanular urethra that forms the "fossa navicularis" has a wider caliber than the proximal urethra. Its vertical elliptical shape resembles a laterally compressed slit-like passage. The fossa navicularis is covered by a thin layer of fibrous tissue ("septum glandis") which is an extension of tunica albuginea of the corpus cavernosum and the corpus spongiosum. Our hypothesis is based on the results of MRI of the glanular urethra and the basic principles of fluid dynamics. We analyzed the flow dynamics of urine on this particular component of the urethra in terms of shape and structural properties. Because of its wider caliber than the proximal urethra, the glanular urethra (fossa navicularis) should cause an increase in pressure and a decrease in velocity of the urine flow. The navicular shape of the fossa and its elliptical external opening (the meatus) should allow urine to be expelled at higher flow rates and at opposite angles at the upper and lower corners which make the wave-like shape of the urine. It can be said that the changes in the volumetric form, pressure and velocity, as well as the wave-like shape of the urine flow are caused by the "fossa navicularis" covered by the "septum glandis". We propose that the "fossa navicularis" and "septum glandis" play a role as 'flow control chamber" in controlling the flow of the urine exiting the urethra, which must be taken into account for successful functional reconstruction of hypospadias.