Correcting VC is a critical initial step in hypospadias repair and has a direct impact on the subsequent choice of urethroplasty techniques. The strategies for VC correction and the selection of surgical techniques for hypospadias repair have evolved over the years. However, there is limited information available on the effectiveness of VC correction using different strategies, as well as objective analyses of surgical options for different types of hypospadias. As the National Center of Children’s Health and a referral centre for complex hypospadias in China, we aim to present our findings and expertise in managing hypospadias. In this prospective study, we collected comprehensive clinical data from 434 patients who underwent hypospadias repair. The results of this study on the effectiveness of different VC correction strategies will provide valuable insights into the causes of VC in the Chinese population.
Management of VC
The surgical procedures for VC correction in hypospadias aim to address the underlying causes of the curvature. A stepwise approach is followed, starting with skin degloving and dartos dissection. If a curvature greater than 30° persists, UPT without mobilising the urethral plate is recommended. If the curvature persists by more than 30° after UPT, ventral penile lengthening (VPL) is performed.3 However, in our centre, VPL is not commonly used due to concerns regarding potential adverse effects such as erectile dysfunction, haemorrhage and scar healing issues related to the albuginea incision. Long-term studies evaluating the outcomes of VPL are lacking.3 18 When there is significant bleeding during the incision or the need for closure with a flap or graft, it may affect the surgical procedure and postoperative urethral healing. A study conducted in 2017 reported that UPT combined with DP achieved satisfactory straightening in all cases of severe hypospadias, without the requirement for VPL.19
In our study, we observed a higher proportion of severe preoperative VC and proximal hypospadias compared with previous reports.20 21 Similar to our result, Snodgrass and Prieto have found that 19% of patients achieved a straight penis after degloving alone, 31% had VC less than 30° after degloving and underwent DP, and 50% had VC more than 30°.22 These results suggest that persistent VC after degloving may indicate a shortened urethral plate and/or corporal disproportion.
Skin degloving is an important step in hypospadias repair and can improve VC.23 24 However, the effectiveness of degloving alone for achieving penile straightening varies across studies. One study using lateral photographs to assess curvature reported complete VC correction by degloving in 100% of cases with VC less than 45° and 74% of cases with VC greater than 90°.25 On the other hand, Weber et al found that degloving alone was sufficient for VC correction in 77% of mild cases (less than 30°), 30% of cases with 30°–45° and only 2% of cases with VC greater than 45°.26 Therefore, the efficacy of degloving appears to be inversely related to the severity of preoperative VC, which aligns with the trends observed in our study. We found that more than half of patients with mild preoperative VC achieved a straight penis after degloving, but it was not as effective for correcting severe VC.
In our analysis, we found that the correction achieved by DP after UPT was higher than DP after degloving alone. This suggests that DP may be more effective and durable after UPT, as the continuous ventral tethering caused by the elasticity of the urethra and urethral plate is relieved.19 This finding is consistent with a study that reported a lower rate of recurrent VC after DP with UPT compared with DP without UPT (0% vs 36.5% of patients, p=0.002).27 DP is generally recommended for VC less than 30°, and the effectiveness observed in this study exceeds that standard. However, the potential risk of recurrent VC after DP necessitates long-term follow-up in future research.
It was thought in the 1980s and 1990s that UPT might not substantially improve curvature.28 However, a 2017 study reported that UPT alone achieved penile straightening in 35% of cases.29 In proximal hypospadias, it has been reported that the penis can be straightened without UPT in 13%–74% of cases.25 29 In our series, a straight penis was achieved without UPT in 43.8% of cases. These observations suggest that a shortened urethral plate could contribute to VC, which may be the primary aetiology in some cases. Acimi et al25 reported VC correction ranging from 0° to 20° obtained by mobilising the urethral plate In our study, the VC correction achieved by UPT was 20° (10°, 30°). Overall, UPT was in demand and effective in the stepwise approach for managing VC.
Surgery techniques for hypospadias repair
The field of hypospadias surgery originated in the late 19th century with the contributions of Thiersch and Duplay.30 31 Since then, numerous surgical techniques have been developed. Our study also demonstrates the variety of techniques used for hypospadias repair. However, it is important to note that comparable functional outcomes can be achieved with different techniques, and a large number of surgical options can increase the risk of complications.32
The TIP technique has become the preferred treatment for distal and middle hypospadias due to its reliability and high success rates as demonstrated in large series.33–37 For distal hypospadias, alternative techniques such as MAGPI and Mathieu procedures are also available.38 39 The Onlay technique involves using a preputial island flap when the urethral plate is unhealthy or too narrow.2 Our study reflects similar trends, with TIP being the most commonly used technique for distal hypospadias repair, while Onlay, TIP and TPIFU are the main surgical techniques for middle hypospadias repair. According to a worldwide survey, staged repair was the preferred option for proximal hypospadias repair, chosen by up to 76.6% of respondents.17 However, in our centre, a staged approach was chosen for only 17.2% of patients. While a staged approach may have a lower complication rate, it requires two surgical procedures, whereas a single-stage approach can avoid the need for a second procedure in approximately two-thirds of patients.40 Therefore, most of our surgeons prefer the single-stage TPIFU technique for proximal hypospadias repair when the preputial flap is sufficient to repair the urethral defect. We believe that reducing the need for additional surgical procedures may be particularly beneficial for the patients.
Limitations
This study has several limitations that should be acknowledged. First, there may be interobserver variability in the evaluation of VC due to the involvement of multiple surgeons in assessing VC during artificial erection. This variability could introduce bias into the results. Additionally, there may be variations in VC measurement methods among previous studies, making it challenging to directly compare the findings. Another limitation is the uniform distribution of patients among the different strategies for VC correction. This may affect the outcomes and limit the ability to draw definitive conclusions about the effectiveness of each strategy. Furthermore, this study only presents data on the surgical procedures for hypospadias repair and lacks long-term follow-up data. These limitations should be taken into consideration when interpreting the results of this study and further research with larger sample sizes and comprehensive follow-up is needed to provide more robust evidence in the field of hypospadias surgery.