erasmus urology research
Hypospadias is a congenital abnormality of the penis defined as an abnormal ventral opening of the urethral meatus, a ventral curvature and an abnormal foreskin. In most cases the meatus is localized on the distal penile shaft or at the corona between the penile shaft and glans. An abnormal “dorsal hooded” foreskin is nearly always present. Marked ventral curvature is found in the majority of proximal cases and in around 10% of distal cases. With an incidence of around 3.8 in 1,000 male births, this abnormality is one of the most common congenital abnormalities of the genito-urinary tract.
Uncorrected hypospadias can cause psychological problems due to embarrassment for the abnormal foreskin, abnormal meatal location and penile bending. Furthermore, penile functional problems may occur, such as a deflected urinary stream or, in adult life, a sexual dysfunction due to the penile curvature.
The goals of hypospadias repair are to create a functional neo-urethra, to straighten the curvature and to achieve an anatomically normal appearance of the penis with minimal complications.
Although the application of new surgical techniques has improved the outcomes over the past decades, complications following hypospadias repair may still occur. The overall complication rate reported in the literature varies considerably from around 10 to 50%. The most frequent complication is the development of a urethrocutaneous fistula, reported to range from around 5 to 25%. However, these complication rates are mainly based on retrospective, non-standardized and possibly incomplete registrations. It is therefore unclear whether this wide variability in complication rate is related to surgical technical factors, patient selection, deficient follow-up and/or unreliable outcome reports.
Abnormal anatomic appearance is the most important indication for operative treatment in more than 80% of patients in which the meatus is in a distal- or mid-shaft position. Still, boys who underwent such correction tend to have a more negative genital perception and may be more inhibited in sexual contacts than boys without hypospadias, especially when appearance outcome is poor. Therefore, modern hypospadias surgery should focus on creating an as normal anatomic penile appearance as possible.
Reconstructive hypospadias surgery aims to achieve a normal urinary stream and continence with the ability to void while standing up. In literature, an obstructive flow pattern is often reported, although mostly without symptoms and with a great potential for normalization at puberty. It is interesting to evaluate whether different types of urethroplasty techniques and diameters are associated with different voiding function and uroflowmetry outcomes.
In view of all these considerations the Dutch Working Group of Pediatric Urology in October 2008 initiated a prospective national multi-center study called the “Dutch Hypospadias Study” to accurately evaluate and (possibly) improve the outcomes of hypospadias surgery. This study determines the results of different surgical techniques and different surgeons, analyzes prognostic non-modifiable factors and modifiable surgical and non-surgical factors and identifies techniques with the lowest complication rates and best appearance and functional outcomes (“best practices”).
At the start of this national study there was no objective, reproducible and validated appearance outcome scoring system which incorporates not only all surgically correctable aspects but also key elements of objectivity [53,59-64]. To fill the gap, we designed the Hypospadias Objective Penile Evaluation (HOPE)-score and evaluated and reported its high reliability and validity. Subsequently, we used the HOPE-score to assess the appearance outcome in our study population.
So, the “Dutch Hypospadias Study” aims to identify aspects of the surgical technique that need critical attention. In time, the surgical procedures associated with the best practices will be recorded on video which will be distributed to the participating surgeons. By adopting these procedures, surgeons may be able to reduce their complication rates and improve their appearance outcomes and functional results. In this way, by reliable registration of surgical techniques and outcomes as well as by initiation of a cycle for improvement, we expect to optimize the outcomes for our hypospadias patients.
People working on the project
Fred van der Toorn
pediatric urologist FEAPU