Clinical characteristics, complications and satisfaction of megameatus intact prepuce (MIP) hypospadias variant: a 15 year retrospective study

Abstract

Background

To analyze the clinical characteristics, complications and patients satisfaction of MIP hypospadias variant.

Methods

A retrospective analysis was performed for 31 patients with MIP admitted to our hospital from January 2008 to February 2023. All enrolled patients underwent telephone follow-up and a survey was conducted on the satisfaction of patients and their families. Outcome analysis was focused on clinical data includes age, position of the meatus, penile curvature, type of repair, complications and satisfaction survey results. Statistical analyses were performed using R software.

Results

The average age of 31 MIP patients was 92.1 ± 40.7 months, and the median follow-up time was 49.0 [21.0–82.2] months. Twenty one patients (67.7%, 21/31) had ventral curvature and no dorsal curvature was observed. All cases were divided into chordee group and no chordee group. There was a statistical difference in age (80.4 ± 41.6 Vs 117.0 ± 26.0 months) and weight (22.7 [15.8–35.0] Vs 45.0 [32.0–46.0] kg) between the two groups. Six children (19.4%, 6/31) experienced post-operative complications; however, none required reoperation. The only risk factors for complications were the meatus position and whether urethroplasty was performed.Only the occurrence of complications may affect patients satisfaction.

Conclusions

MIP hypospadias variants can exhibit severe ventral curvature. Surgery can achieve good results with a low incidence of complications. A satisfactory skin appearance and adequate curvature correction are key concerns for both patients and parents.

Background

Megameatus intact prepuce (MIP), a distinctive form of hypospadias, manifests with an approximate incidence of 1 in 10,000, representing 1% to 3% of all hypospadias cases [1]. The precise incidence of MIP remains elusive, partly due to some patients not seeking medical attention [2]. Initially described by Juskiewenski et al. in 1983 [3], MIP received a comprehensive elaboration from Duckett and Keating, who introduced the “pyramid procedure” for surgical intervention [1]. Despite the availability of retrospective studies, there is a lack of research that combines large sample sizes, comprehensive clinical data, long-term follow-up, and patient satisfaction assessments. The study aims at analyze the clinical features, complications, and patient satisfaction concerning MIP hypospadias, as well as to outline clinical presentations observed in our institution, contrasting them with findings from other research.

Methods

A retrospective analysis was performed for 37 patients with MIP who were admitted to our hospital from January 2008 to February 2023. The categorization of these cases was based on the meatus’s location, namely glans, coronal sulcus, and distal penis. Follow-ups were scheduled for all patients six months post-surgery and subsequently on an annual basis. Prior to composing this article, a comprehensive telephone follow-up was carried out, including a survey assessing the satisfaction of patients and their families. The analysis included clinical characteristics such as age, meatal position, degree of penile curvature, types of hypospadias, methods of penile curvature repair, complications, and satisfaction survey outcomes. Patients who had previously undergone surgery in other hospitals, and who had incomplete medical records or had not completed telephone satisfaction surveys were excluded. Among the 37 patients with MIP, 6 patients were excluded because they did not receive or refused to participate in the telephone satisfaction surveys.

The surgical techniques employed included meatal advancement and glanuloplasty incorporated (MAGPI) procedure, tubularized incised plate urethroplasty (TIP), Duckett, Mathieu procedures, circumcision, and penile curvature correction. Patients were categorized into two groups based on the surgical approach: the urethroplasty group (TIP, Duckett, Mathieu, and MAGPI) and the non-urethroplasty group (circumcision and penile curvature correction). Postoperative infection prevention involved the use of cephalosporin antibiotics. In cases of urethroplasty, catheters were maintained for 28 to 30 days. For surgeries addressing penile curvature without urethra formation, catheters were retained for 5–7 days. Circumcision alone necessitated no indwelling catheter.

The assessment of penile curvature was performed intraoperatively using an artificial erection test, where saline solution was injected following penile skin degloving. The curvature was measured with a goniometer, and correction was indicated for curvatures exceeding 15 degrees. In cases of ventral curvature between 15 and 30 degrees, plication sutures with 4–0 polypropylene were placed at the point of maximal curvature. For curvatures greater than 30 degrees, particularly when the urethra impeded straightening, transection of the urethral plate was considered [4].

Statistical analyses were performed using R software (version 4.0.3, http://www.r-project.org). Continuous data that did not follow a normal distribution was reported using median and inter-quartile range and analyzed by Mann–Whitney U test. Chi-square test or Fisher exact test was used to compare variables between groups. Statistical significance was defined as P < 0.05.

Results

Clinical characteristics

The study encompassed 37 patients diagnosed with the MIP hypospadias variant between 2008 and 2022. Six patients were excluded as they did not receive or refused telephone satisfaction surveys, leaving 31 patients with complete clinical data who were contacted for telephone follow-up. This resulted in a 16.2% rate of lost follow-up. Among the 31 MIP patients, the average age was 92.1 ± 40.7 months, with a median follow-up duration of 49.0 [21.0–82.2] months.

Among 31 MIP patients, the artificial erection test during surgery revealed that 21 (67.7%) presented with ventral curvature, with no instances of dorsal curvature observed. As detailed in Table 1, the patients were categorized into two groups: those with curvature and those without. The average age in the curvature group was 80.4 ± 41.6 months, markedly different from the 117.0 ± 26.0 months in the no curvature group (P < 0.01). Similarly, a significant contrast was found in median weights between the groups: 22.7 [15.8–35.0] kg in the curvature group versus 45.0 [32.0–46.0] kg in the no curvature group (P = 0.02). In the curvature group, the urethral openings were located as follows: 14 in the glans, 6 in the coronal sulcus, and 1 in the distal penis. In the no curvature group, there were 4 in the glans, 6 in the coronal sulcus, and none in the distal penis, with no statistically significant difference (P = 0.23). Following degloving, 12 cases required dorsal plication to correct persistent curvature, while one case involved urethral plate transection due to severe curvature. For further details, refer to Fig. 1.

Table 1 Clinical characteristics of patients with and without curvature

Fig. 1

Clinical characteristics and treatment of 31 MIP patients

Complications and treatment

Post-operative complications were observed in 6 children (19.4%), though none required reoperation. The complications included 2 cases of adherent prepuce, 2 instances of urethral strictures, 1 case of a small urethral diverticulum that did not require surgical intervention, and 1 case of glans dehiscence caused by accidental catheter removal with excessive force by the patient. Among the urethral strictures, one case was identified after catheter removal and successfully treated by reinserting the catheter, followed by a delayed removal 2 months post-surgery. In the other urethral stricture case, parents reported a thin stream of urine, but the child did not face any difficulty in urination, and the stream’s thickness remained stable up to the writing of this manuscript. The patient is currently under continuous observation, and surgical intervention has been deemed unnecessary at this time.

As shown in Table 2, we divided patients into no complication group (N = 25) and complication group (N = 6). The only statistical difference between the two groups was the position of the urethral opening and satisfaction rate (p < 0.05).

Table 2 Risk factors for postoperative complications

Regarding satisfaction with surgical outcomes, 85.7% of parents and patients with penile curvature expressed satisfaction, compared to 90.0% in those without curvature. As illustrated in Fig. 2, of the 21 children identified with curvature, 13 underwent urethroplasty, achieving a satisfaction rate of 76.9%, while the 8 who did not undergo the procedure reported 100% satisfaction. No significant statistical difference was observed between them (P = 0.26). Twenty-three cases of abnormal urethral openings were identified intraoperatively, while 8 cases were detected preoperatively. Among the intraoperatively diagnosed cases, 87% were satisfied with the outcomes, compared to 87.5% in the preoperatively diagnosed group, with no statistically significant difference between the two groups (P = 1.00).

Fig. 2

Satisfaction survey

Discussion

In 1983, Juskiewenski et al. described MIP as "anterior hypospadias," defining it as a condition in which the meatus is positioned at the base of the glans, near or at the balano-preputial groove, usually without significant curvature [3]. Despite existing studies on MIP, unresolved questions remain, such as the prevalence of curvature in MIP, variations in complications relative to conventional hypospadias, and factors influencing post-surgical patient satisfaction. To address these uncertainties, we reviewed clinical data from MIP surgeries performed in our hospital over the last 15 years, aiming at furnish comprehensive and reliable reference material for our readers.

Ben-David et al. conducted a retrospective examination of 118 MIP hypospadias variant cases, observing a median repair age of 1.1 years. They discovered penile curvature in 29 children (24%); of these, 23 exhibited dorsal curvature (19%) and 6 ventral curvature (5%) [5]. In contrast, our study identified no instances of dorsal curvature, with ventral curvature present in 67.7% (21/31) of the patients. This notable disparity may be attributable to the following factors:

• 1. Neonatal Male Circumcision and Age at Surgery: In Ben-David’s study, all MIP patients underwent neonatal circumcision, leaving the presence of curvature before the procedure uncertain. They postulated that either ventral or dorsal curvature might arise as a consequence of skin deficiency from circumcision and subsequent secondary healing. Conversely, in our cultural context, neonatal circumcision is uncommon. Thus, the penile development was not influenced by skin deficiency, and MIP repair occurred later in life, allowing for more accurate observation of penile curvature during surgery. This suggests that dorsal curvature may be linked to a deficiency of skin.

• 2. Undiagnosed MIP: In our study, patients with curvature underwent surgery at a younger age and lighter weight compared to those without curvature (mean age 80.4 ± 41.6 months vs. 117.0 ± 26.0 months, P < 0.01; median weights 22.7 [15.8–35.0] kg vs. 45.0 [32.0–46.0] kg, P = 0.02). For children not circumcised, the meatus’s position may often go unnoticed by both parents and the children themselves. Consequently, pronounced ventral curvature, leading to observable issues like urinating on one’s shoes, tends to prompt medical consultation more readily. On the other hand, dorsal curvature, typically more apparent during erection, poses a diagnostic challenge in older children due to embarrassment to disclose such issues to parents.

• 3. Ligamentous Structural Forces Between the Corporal Bodies and the Glans: Ozbey sug’gested that in MIP patients, dorsal curvature of the glans may result from the absence of the lower median septum, combined with the dominant tensile force of the distal ligament [6]. He underscored the importance of examining and exploring the ligamentous framework and the intricate fibrous layers within the glans penis.

Snodgrass et al., in their study of 63 MIP patients treated with TIP, noted only one case of postoperative urethral fistula [7]. They concluded that neonatal circumcision does not increase complications in later MIP treatments. They recommend routine circumcision in newborns with a normal-appearing foreskin, dismissing medical and legal concerns regarding hidden urethral anomalies. Similarly, Pieretti et al. found no adverse impact of prior circumcision on the outcomes of MIP variant hypospadias surgeries [8]. Contrarily, in our patient cohort, one case necessitated urethral plate transection due to severe curvature, employing the Duckett technique. We believe that the risk is inherent, thus suggesting that circumcision should be performed with caution for children with potential penile anomalies.

During the telephone follow-up, we limited our questions to satisfaction with penile function and appearance. This streamlined approach facilitated greater willingness among patients and parents to participate in the satisfaction surveys. Our findings revealed that the precise correction of the urethral position was not a pivotal factor influencing satisfaction. Instead, concerns centered around postoperative complications, residual penile curvature, and skin appearance. Over the 15 years covered in this study, MIP represented a mere 0.4% (31/7782) of all hypospadias cases treated in our hospital. The low incidence indirectly validates the satisfaction survey outcomes, indicating that many MIP patients, in the absence of curvature, opt against surgical intervention, preferring to retain a megameatus.

Conclusions

MIP hypospadias variants can present with severe ventral curvature, requiring surgical correction. Surgery generally yields good outcomes with minimal complications, though achieving sufficient curvature correction and a cosmetically acceptable appearance are key concerns for both patients and parents. While complication rates are low, attention to detail in surgical technique is crucial for ensuring long-term functional and aesthetic success. Close follow-up is needed to monitor growth and detect any late complications.