Vol 16 No 01 January-February 2019 67 PEDIATRIC UROLOGY Management of Congenital Urethral Strictures In Infants. Case Series Dalia Gobbi 1*, Francesco Fascetti Leon 2, Michele Gnech 3, Marina Andreetta 2, Paola Midrio 1, Piergiorgio Gamba 2, Marco Castagnetti 3 Purpose: Infra-vesical obstruction is uncommon in infants and generally due to urethral valves. Congenital ure- thral strictures (CUS), instead, defined as a concentric narrowing of the urethral lumen, are exceedingly rare in infants. Materials and Methods: We reviewed our experience with 7 patients treated at our institution for CUS 1cm). Success of treatment was defined as ab- sence of urinary symptoms at follow-up, and radiolog- ical or endoscopic documentation of resolution of the stricture. Statistical Analysis Only descriptive statistic was used. RESULTS Seven patients met the inclusion criteria for study (Ta- ble1). In a single patient, the urethral stricture was an isolated condition, 3 had a Prune Belly Syndrome (PBS) and the remaining 3 had Ano-Rectal Malformation (ARM). In no patient the stricture was diagnosed prenatally but 4 had upper tract dilatation detected on prenatal ultra- sound. Four patients (2 PBS and 2 ARM) presented with urinary retention and poor stream. One patient with PBS was urinating only via a patent urachus, whereas in the last patient with ARM the stricture was detected for the impossibility to pass a catheter during surgery for creation of a colostomy at 24 hours of life. The single patient with an isolated stricture presented at 1 month of life with an urosepsis while he was followed con- servatively for bilateral hidroureteronephrosis (HUN) elsewhere. On ultrasound, 5 patients had evidence of bilateral HUN. The patient with the isolated stricture had also ultrasound evidence of penile cysts. Five patients had impaired renal function at diagnosis and 3, all PBS, have required renal transplantation so far. Table 1. Patients’ characteristics and management of the stricture Treatment of Stricture Pt Associated Presentation Upper tract Renal Urinary tract Stricture Stricture Age at 1st 2nd Additional surgery condition status at presentation function diversion at location length (mos) treatment treatment presentation PADUA 1 (MZ) PBS Prenatal Bilateral HUN Renal Vesicostomy Penile > 1 cm 10 up to 12 Fr detection of (No VUR) Failure at birth Bil HUN, (RTx) poor stream at birth 2(GF) PBS Prenatal Bilateral HUN Renal Vesicostomy h Bulbar < 1 cm 1 EU detection of (No VUR) Failure at birt (cold knife) Bil HUN, (RTx) poor stream at birth 3 (DC) None Prenatal Bilateral HUN Mild Epicistostomy Penile >1 cm 1 Urethroplasty (Prenatally detection (VUR Rt) Chronic tube then detected bil of Bil HUN renal failure scrotal HUN) Urosepsis at (Estimated Urethrostomy 3 weeks of age GFR 70 ml/min/1,73m2) 4 (EB) ARM Impossibility Bilateral Normal Epicistostomy Bulbar <1 cm 5 EU EU Urethroplasty (fistula to pass a HUN renal tube (cold knife) (Laser) with catheter at (VUR Bil) function bladder colostomy -neck) (2 days of life) 5 (FZ) PBS Voiding Bilateral Renal None Penile >1 cm 2 PADUA via a HUN Failure up to 12 Fr patent (VUR Rt) (RTx) urachus 6 (JT) ARM Poor Normal Epicistostomy Bulbar <1 cm 6 PADUA EU urinary renal tube up to 10 Fr (cold knife) stream function and impossibility to pass a catheter 7 (AL) ARM Poor urinary Normal Vesicostomy Penile >1 cm 1 Urethroplasty stream and renal impossibility function to pass a catheter Abbreviations: PADUA,progressive augmentation by dilating the urethra anterior; PBS, Prune-Belly Syndrome; ARM, Anorectal Malformation; VUR, vesicoure- teral reflux; HUN, hydro-ureteronephrosis; rTX,renal transplantation; EU, endoscopic urethrotomy Congenital urethral strictures – Gobbi et al. Pediatric Urology 68 Vol 16 No 01 January-February 2019 69 In all cases, but the one urinating via the patent urachus, initial management included percutaneous supra-pu- bic diversion of the bladder. A combination of retro- grade urethrography and micturition cystourethrogra- phy (MCUG) was used to confirm the diagnosis and determine the extension of the stricture in 7 out of 8 cases. All strictures were located in the anterior urethra (Figure 1). On MCUG, a dilated proximal urethra was present in all patients, and 4 cases had associated vesi- coureteral reflux. All patients underwent endoscopic assessment. In 3 cases (2 PBS, 1 ARM), a 3 Fr urethral catheter could be passed into the bladder and an attempt to a PADUA was elected. The percutaneous drainage was converted in a formal vesicostomy in 2 such cases. The PADUA was successful in the 2 PBS patients whereas the pa- tients with ARM went on with a cold knife EU that was successful. EU was performed as primary procedure in two patients (1 PBS, 1 ARM). A cold knife incision was successful in the patient with PBS whereas EU failed in the other patient despite two attempts, one with cold knife and the other with holmium laser. In the remain- ing two patients (1 isolated stricture and 1 ARM), the stricture was considered unsuitable to attempt an endo- scopic management. Therefore, a scrotal urethrostomy and a formal vesicostomy were performed, respective- ly, in the prospect to perform a primary urethroplasty on an elective basis. Formal urethroplasty was successful in both these patients as well as in the one with ARM where two EU failed. Overall, none of the 3 patients with PBS required a formal urethroplasty vs. 3 of the 4 remaining patients. DISCUSSION In children, urethral strictures, defined as a concentric narrowing of the urethral lumen, generally follow per- ineal traumas or urethral surgery, such as hypospadias repair or surgery for anorectal malformation(2,3,4), and occur after the first year of life. In infants, instead, in- fra-vesical obstruction is most commonly due to ure- thral valves whereas congenital urethral strictures are exceedingly rare. We identified 7 patients undergoing treatment for congenital urethral strictures at our cen- tre over a 10-year period. These patients are peculiar in many respects. To begin with, 6 out of 7 had associ- ated conditions including PBS and ARM, 3 each. The associated underlying condition seems to have impor- tant implications both to explain the development of the stricture and for its management. It is indeed of note that the stricture could be fixed by progressive ure- thral dilatation or by EU, irrespective of its length, in all the 3 patients with PBS whereas 3 of the other 4 patients required a formal urethroplasty. Stumme was the first suggesting that all the features of the PBS might be due to an in utero bladder outlet obstruction distal to the prostatic urethra. This obstruction would be typical transient and should disappear before birth(9). We assume, therefore, that our PBS patients had some degrees of developmental delay of the urethral lumen, but not an abnormal urethral wall, which can explain the good response to dilatation or EU in contrast to the stricture in the other patients(9). The other major group of patients included children with high ARM. Also in these patients, the presence of urethral stricture is not surprising as it might be part of the developmental de- fect leading to the formation of a rectal-urinary fistula. In keeping with previous reports, we noticed that under these circumstances, dilation with or without urethrot- omy is fraught with a high failure rate(10,11). This would be consistent with a more significant abnormality of the urethra. An additional problem peculiar to this group is that the presence of a recto-urethral fistula can compli- cate the diagnostic workup. Radiographic appearance of the urethra can be altered by inadequate passage of contrast in the urethra distally to the fistula opening. Moreover, in one patient, the anomaly was discovered due to the impossibility to pass a catheter at the time of colostomy opening during the neonatal period before the urinary stream could be properly assessed and any radiological study of the urethra planned. Still, this is a sign difficult to interpret since urethral catheterization in ARM patients may be demanding per se due to the presence of a recto-urethra fistula. Anyway, our series shows that this can be the first sign of a primary disor- der of the urethra. Regardless of the nature of the stricture and the associ- ated condition, unless the patient has developed a pop off mechanism such as our patient with a persistent ura- chus, the first step in the management of these patients should be, in our opinion, the achievement of urinary diversion to preserve renal function. Placement of a per- cutaneous epicystostomy tube is the option of choice at the outset, particularly considering that most of these patients present without a suspicion of a urethral stric- ture and can be symptomatic with acute urinary tract infection or also urosepsis. This diversion also allows checking safely bladder emptying after treatment of the stricture by intermittent closure of the tube. The draw- back is that tube blockage or dislodgment is common in infants, therefore in a few cases conversion to a formal vesicostomy can be advantageous if the stricture tends to recur or to temporize final surgery. In patients with penile stricture a urethrostomy allows to bypass the Figure 1. MCUG performed via a suprapubic catheter. The white arrow shows a long stenosis involving the anterior urethra, with a proximal (posterior) rosary-like dilation. The white star points to a radiopaque marker located on the basis of the penis. Congenital urethral strictures – Gobbi et al. stricture while preserving bladder cycling. If this kind of diversion is elected the final repair can be easily post- poned to an older age. However, diversion of the urinary flow proximally to the stricture may lower the success of dilatation and endoscopic incision of the stricture, as the urethra is no longer distended by the urinary flow during healing process and this might cause stricture re- currence. We selected this diversion in one patient and he was indeed scheduled for subsequent urethroplasty. It is noteworthy, anyway, that despite an early diversion 4 of our 7 cases in present series presented with renal failure, and 3 required renal transplantation eventually. This clearly depends from the degree of renal damage developed prenatally already. After urinary diversion, treatment options for anterior urethral strictures include wire-guided dilation, direct vision internal urethrotomy, and open surgery. The lat- ter includes stricture excision and direct anastomosis, or augmentation urethroplasty with interposition of a graft as an onlay or inlay in the narrowed urethral segment (3-5). Reportedly, urethral dilatation has the lowest suc- cess rate, ranging from 20% to 55%. It is considered suitable only for short and mild strictures. Moreover, repeated attempts are discouraged and change to other strategies is recommended after the first or the second failure. As mentioned above, in our experience ure- thral dilatation worked in PBS patients, perhaps due to the peculiar nature of the stricture in these patients. It should be noted that we performed the dilatation using the PADUA technique (8). This procedure was first de- scribed in the late 80s specifically for anterior urethral hypoplasia. The principle is to avoid rapid dilation. Urethral dilatation should occur passively. Stent size is progressively increased at one-week intervals until an adequate caliber, of at least 8 Fr, is achieved. In a few cases, we managed to change the catheter over a guide in an outpatient setting. The final caliber was steadily achieved after a median of 4 weeks. We consider this approach easier than balloon dilation, which requires the child to undergo repeated sections under fluorosco- py. Furthermore, the success rate of balloon dilatation appears unsatisfactory(8-9). In contrast, formal urethroplasty, with a success rate ranging from 80% to 95 %, is reportedly the most ef- fective treatment option for urethral strictures in chil- dren(2,3,8,9). Urethroplasty, however, is also the most in- vasive option and carries a specific morbidity. In our opinion, it remains the option if less invasive manoeu- vres fail or if the strictures cannot be negotiated at all during initial endoscopy. Direct vision internal urethrotomy stays somewhere in between urethral dilatation and formal urethroplasty and this is generally recommended as primary treatment for short (less than 1 cm) urethral strictures. Neverthe- less, a notable technical problem related to the endo- scopic treatment of urethral stricture in infants is that urethral instrumentation can be difficult with the small endoscopic instruments required in this age group and not as effective as with the instruments used in older children and adults. For instance, our subjective impres- sion was that the small cold knifes available for the 8 Fr and 9.5 Fr cystoscopes are generally ineffective in ob- taining a satisfactory incision of a stricture. Of course, this is likely to improve with the development of new technologies. The holmium laser seems to allow for a more effective incision, and the smaller fibres easily Congenital urethral strictures – Gobbi et al. fit in endoscopes as small as 7.5 Fr. Though, we used the holmium laser in one case and despite the incision looked deep and net, the stricture recurred and required a formal urethroplasty eventually. Given the lack of solid evidence, we generally individ- ualized the treatment based on patient characteristics. Moreover, the treatment of the stricture has to be put in the contest of the other surgeries required, such as in ARM patients. In general, once an adequate urinary di- version is ensured, unless in cases of very long and se- vere strictures that we scheduled for urethropalsty from the outset, we think that a stepwise approach moving from dilatation, to endoscopic incision to formal ure- throplasty might be the most reasonable strategy. This, however, can be quite a long process requiring months to be accomplished. CONCLUSIONS Diagnosis and treatment of CUS in infants and children remains difficult to standardize. The paucity of cases in the literature does not allow an agreed flowchart and treatment has to be tailored to each single patient. Uri- nary diversion should be achieved at presentation to avoid progressive renal damage in infants that can al- ready have an impaired renal function. Following man- agement should be tailored based on the location and length of the stricture, and the associated condition. In our opinion a stepwise approach should be favoured. Anterior strictures in patients with PBS are likely to be fixed with progressive dilatation irrespective of their length, whereas this treatment modality is unlikely to be effective in other patients. In the latter, an endoscopic urethrotomy can be attempted, but if it fails urethroplas- ty should be considered. Placement of a formal vesicos- tomy or, if possible, a urethrostomy depending on the location of the stricture, allows temporizing this surgery until after one year of age. CONFLICT OF INTEREST There are no conflicts of interest to be disclosed. REFERENCES 1. Dewan PA, Keenan RJ, Morris LL et al. Congenital urethral obstruction: Cobb’s collar or prolapsed congenital obstructive posterior urethral membrane (COPUM). Br J Urol. 1994;73:91-5. 2. Banks FC, Griffin SJ, Steinbrecher HA, Malone PS. Aetiology and treatment of symptomatic idiopathic urethral strictures in children. J Paediatr Urol. 2009;5:215-8. 3. Kaplan GW, Brock JW, Fisch M, Koraitim MM, Snyder HM. 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