Most surgeons choose TIP urethroplasty for patients with distal hypospadias with mild or no chordee, and we plan to use the onlay island flap technique to treat midshaft and proximal hypospadias with small glans. The surgical treatment effect for hypospadias is good; patients obtain a satisfactory penile appearance, the slit-like urethral orifice is located at the head of the penis, the penis is straightened satisfactorily, the urinary line shows a horizontal parabola, adults can have a normal sexual life, and the incidence of postoperative complications is low. However, when hypospadias is combined with small glans, the difficulty of surgery increases, and the incidence of complications, especially meatal stenosis and glans dehiscence, increases significantly. We hope to discover a method to reduce the incidence of these complications.

The literature on glans reduction techniques is limited. Qin et al. applied limited volume reduction of dorsal navicular fossa in the treatment of hypospadias, finding the technique to be safe and feasible, with the potential to improve the morphology of the external urethral opening and urine flow direction [6]. Additionally, Qin et al. utilized cavernosum reduction technology in glanuloplasty in moderate-to-severe hypospadias repair requiring urethral plate division, believing that this approach can reduce postoperative complications [7]. However, neither of these studies addressed the size of the glans, whereas the technique presented in this study is primarily applied to cases of hypospadias with small glans. The local volume reduction of the dorsal glans groove technique we adopted not only allowed the formed urethra to reach the glans head but also significantly reduced the occurrence of postoperative complications, especially postoperative meatal stenosis and glans dehiscence. The principle of this technique is to reduce the volume of the penile head moderately to create conditions for a more spacious outflow tract, which is associated with a lower likelihood of urethral stricture. In our study, the incidences of both meatal stenosis and glans dehiscence were significantly lower in Group 2 than in Group 1. Meatal stenosis was observed in 2% of patients in Group 2 and in 16% of those in Group 1. Other authors have reported incidence rates of meatal stenosis ranging from 0 to 14% in patients with hypospadias with small glans [8, 9]. Glans dehiscence was observed in 4% of patients in Group 2 and in 16% of those in Group 1. Other authors have reported that the incidence of glans dehiscence ranges from 3 to 23% in patients with hypospadias with small glans [9, 10].

In our study, there were no significant differences in HOSE scores between the two groups. Acceptable outcomes (score ≥ 14) were reported for 94 patients (88%) in the two groups, and there were no significant differences between Group 1 (48/57, 84%) and Group 2 (46/50, 92%) (P = 0.219). Kurdi MO et al. compared hybrid Mathieu urethroplasty (HMU) and tubularized incised plate urethroplasty (TIPU) for managing distal hypospadias in patients with small glans, and there were no significant differences in HOSE scores between the two groups [9].

For patients with hypospadias with small glans, to avoid postoperative complications, some scholars [11] have only performed urethroplasty to the coronal sulcus rather than glanuloplasty. Khirallah M et al. reported that hybrid Mathieu urethroplasty is an effective and dependable approach for treating distal penile hypospadias, particularly in patients with small glans and a shallow urethral plate. This technique expands the eligibility of the Mathieu procedure, enhances the overall cosmetic outcomes, and maintains a reasonable complication rate [8]. Kurdi MO et al. compared hybrid Mathieu urethroplasty (HMU) and tubularized insulated plate urethroplasty (TIPU) for managing distal hypospadias in patients with small glans. These findings suggest that HMU not only provides better outcomes but also involves a shorter stent duration and a lower incidence of complications than does TIPU [9]. Perovic S introduced a method using a double-faced island flap and/or injection of a hydrogel to enlarge and sculpt small, deformed glans [12].

The best size of the catheter for placement after hypospadias surgery remains a topic of discussion, especially for patients with small glans. Small glans cannot house the neourethra without tension if the catheter is too large. Some scholars believe that a catheter with a large diameter should be used as often as possible. Other scholars [13] believe that a small (6 Fr) catheter can prevent meatal stenosis, whereas some practitioners [14] choose the size of the catheter according to the age of the child. Our experience is to use transurethral diversion for urinary drainage, and we prefer to use a small silicone catheter, generally a 6 Foley catheter because the local volume reduction of the dorsal glans groove technique results in a wide external urethral opening; therefore, it is not necessary to use a large catheter to prevent meatal stenosis; moreover, a small catheter is also conducive to closing the glans wing without tension and decreasing the incidence of glans dehiscence. We encountered instances of urethral catheter blockage, some of which were resolved through bladder irrigation, while others necessitated catheter replacement.

A glans width less than 14 mm is considered an independent risk factor for complications after hypospadias surgery [2]. For decades, hormone therapy has been used before surgery to increase penis size and improve blood flow through penis tissues. Whether and what hormones should be used before surgery for patients with hypospadias with small glans remain controversial. Menon P et al. suggested that testosterone should be used with caution in children with distal hypospadias. Although testosterone therapy can increase the amount of available prepuce tissue, patients receiving this treatment are prone to postoperative infection and prepuce edema, which ultimately increases the chance of wound dehiscence [15]. According to Mohammadipour A et al., preoperative hormone stimulation is not suitable for all children with hypospadias, and regular monitoring of hormone use and cessation of hormone therapy once the surgical requirements are met not only provides better surgical conditions but also reduces the incidence of androgen side effects [16]. Gorduza D et al. reported that it was not possible to demonstrate whether hormones had any effect on reducing the incidence of postoperative complications of hypospadias surgery compared with the placebo [17]. In a prospective study by Mittal S et al., the effect of preoperative testosterone on changes in the glans size of patients who underwent hypospadias surgery was quantified [18]. Using preoperative androgen stimulation, Do MT et al. confirmed that penile length and glans width increased. However, the incidence of postoperative complications associated with preoperative androgen stimulation did not increase [19]. None of the patients in either study group received hormonal stimulation, either preoperatively or postoperatively. In the future, we may consider exploring the use of androgens prior to surgery.

This study has several limitations. First, the use of this technique during surgery results in the loss of glans corpus spongiosum tissue, particularly in patients with small glans, where the available tissue is already limited. Although the amount of tissue loss is relatively minor, it may still affect the sexual sensitivity of the glans, a concern that requires further evaluation. Second, this technique is specifically designed for hypospadias correction surgeries where the urethral plate is preserved and is not applicable to all types of hypospadias repairs. Third, the lack of long-term postoperative postoperative follow-up data on glans volume limits the ability to accurately assess the extent of volume reduction. Lastly, this study is a single-center retrospective study, and multicenter and large-sample randomized controlled clinical trials are needed to provide more robust and generalizable conclusions.