Congenital anomalies usually present as a spectrum with variable expression and different degrees of severity; these are best understood through studying embryology. This report discusses one of the rare congenital anomalies where there is abnormal communication between the lower urinary tract and the anus. This condition may be inadvertently classified as a type of urethral duplication [7]. We believe that proper identification of the true nature of the disease can help to improve and standardize surgical management.

During the early embryonic period (4–6 weeks after fertilization), the developing uro-rectal septum starts dividing the embryonic “cloaca” into anterior urogenital and posterior anorectal components [5, 6]. The urogenital component will give rise to the urinary bladder and the posterior urethra in the male. The process of complete separation of the anorectum from the lower urinary tract may become interrupted by the presence of obstruction (atresia) either at the anal side or the urethra; this would result in persistence of abnormal communication between both tracts (persistent cloacal duct of Reichel) [5, 6, 13]. In the literature, it is well documented among boys with imperforate anus that the rectum usually remains communicating via a fistula with the urinary tract (recto-bulbar/prostatic/bladder neck) [7]. On the other hand, urethral atresia is a much less common disorder; the condition is usually lethal causing fetal death due to severe renal dysplasia and lung hypoplasia unless urine can find its way out (escape) through a patent urachus or persistent communication with the anus [14]. A famous example for the latter condition is aphallia (boys presenting by absent penis and urination through the anus) [10].

In a previous report [10], Macedo et al. referred to the similarity between cases of aphallia (penile agenesis) and the so-called Y-type urethral duplication when they used the same surgical strategy for reconstruction of the lower urinary tract in both groups. In our present study, pelvic MRI examination clearly unveiled significant degrees of corporeal dysgenesis among cases diagnosed as Y-type urethral duplication that would strongly suggest these cases to be part of the same disease spectrum “penile dysgenesis/agenesis”.

Based on embryological explanations and current MRI findings, we may suggest penile dysgenesis to be the primary pathology in cases described as Y-type urethral duplication. The anterior urethra lies within the penis and therefore will be affected by its defective development (penile dysgenesis). This may reach up to complete absence in cases of aphallia (penile agenesis) at the extreme end of spectrum. On the other hand, the posterior urethra was always spared due to different embryologic origin. Significant hypoplasia/atresia of the anterior urethra will redirect the main urinary stream backwards via persistent abnormal communication between the posterior urethra and the anus (persistent cloacal duct of Reichel) [5]. Through studying an autopsy specimen [6], Stephens and Donnellan showed this urethro-anal tract to be devoid of muscle coat; moreover, it showed severe shrinkage during specimen preparation. This may explain the reported high incidence of strictures and failure when using the accessory uro-anal tract in reconstruction of the urethra and would indicate for its true fistulous nature [7]. Sinha et al. reported using a strip of rectal wall in continuity with the posterior ectopic urinary meatus adding extra length to the uro-anal tract during its mobilization to the anterior perineum [15]. Others recommended discarding the accessory uro-anal tract, and instead, to incorporate the orthotopic patent posterior urethra in the repair [6].

The hypoplastic penile urethra is usually reconstructed/replaced by applying the principles of hypospadias surgery: preputial island flaps or grafts (buccal mucosa). Trials of progressive dilatation of the hypoplastic penile urethra (PADUA) [16] are usually prone to failure [3, 9]. This may be related to the dysgenetic nature of penile urethra in these cases [1, 9]. Moreover, the penile urethra may not be perfectly orthotopic within the corpus spongiosum as expected but rather running an ectopic course on the dorsum of the penis [3]. On cystoscopy, Macedo et al. reported ectopic implantation of the hypoplastic urethra into the posterior urethra [8]. The hypoplasia together with the dorsal ectopic course may indicate this penile urethra to be rather an accessory urethra; the latter might have been formed after occurrence of a major vascular accident interrupting the development of corpus spongiosum and the orthotopic penile urethra inside [13]. A similar condition has been described in the female (posterior cloaca), where the urogenital sinus is directed backwards to open through the anus; an accessory urethra running through the tip of the clitoris has similarly been described [17].

The lack of consensus on the best surgical treatment, besides the overall less satisfactory results in the literature, may explain the different treatment options applied for each case in this study. Macedo argued the risk/benefit of complex procedures for complete reconstruction of the urethra up to the tip of penis [8, 11]. Instead, he suggested a permanent perineal urethrotomy for voiding and a functional penis for sexual intercourse [11]. Similarly, Lorenz and colleagues raised a question whether we really need to reconstruct the lower urinary tract in these patients [3]. When adequate bladder drainage is questionable, a permanent supra-vesical channel for clean intermittent catheterization may be a better alternative for these patients and their families; this may reduce number of surgical interventions, shorten hospital stay, and facilitate follow-up [3]. Anyway, the available surgical options and limitations should be clearly and objectively discussed with parents [3, 11]. Whatever was the extent and type of surgical reconstruction, it is of utmost importance to protect the vulnerable upper urinary tract in these patients by keeping them on close long-term follow-up [3]. This can help to avoid terrible situations seen in these cases ending by renal failure [2, 11].

Although this study included only three cases, yet associated penile corporeal dysgenesis was quite evident and well demonstrated in MRI. Further studies on more cases and including other disease variants with functioning penile urethra can help to complete the picture and reach a consensus on the true nature of the disease whether a ‘fistula’ or a ‘duplication’ of the urethra [18]. We believe that proper understanding of the pathology is important to make correct surgical planning and improve outcomes.