Strictures of the neourethra after hypospadias surgery are more common after skin flap repairs than urethral plate or neo-plate tubularizations. The diagnosis of stricture after hypospadias repair is suspected based on symptoms of stranguria, urinary retention, and/or urinary tract infection. It is confirmed by urethroscopy during anticipated repair, without preoperative urethrography. The most common repairs for neourethra stricture after hypospadias surgery are single-stage dorsal inlay graft and 2-stage labial mucosa replacement urethroplasty.
Key points
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Strictures of the neourethra after hypospadias surgery are more common after skin flap repairs than urethral plate or neo-plate tubularizations.
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The diagnosis of stricture after hypospadias repair is suspected based on symptoms of stranguria, urinary retention, and/or urinary tract infection. It is confirmed by urethroscopy during anticipated repair, without preoperative urethrography.
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The most common repairs for neourethra stricture after hypospadias surgery are single-stage dorsal inlay graft and 2-stage labial mucosa replacement urethroplasty.
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The fact that a few adults present with strictures after childhood hypospadias repair does not imply that puberty or sexual activity causes deterioration of the neourethra, or that hypospadias is a lifelong problem.
Prevalence
Fifteen years ago, during the peak of preputial flap hypospadias repairs, urethral strictures were reported as a common complication, occurring in approximately 8% of cases. For example, Duel and colleagues found 38 (7%) of 582 repairs resulted in a stricture following a variety of mostly skin flap or skin graft operations for predominantly proximal hypospadias. Weiner and colleagues found strictures in 9% of patients after tubularized preputial flap repair, versus none using onlay preputial flaps. Two series of Byars’ preputial flap repairs published this year reported urethral strictures in 8% and 12%.
After Tubularizing the Urethral Plate
In contrast, procedures tubularizing the urethral plate (TIP) or a graft neoplate (2-stage preputial or oral mucosa graft repairs) have almost anecdotal prevalences of urethral strictures. For example, the authors reported no strictures in 426 consecutive distal hypospadias repairs with follow-up, all corrected using TIP. They subsequently published urethral stricture occurring in 1 of 24 patients with proximal TIP who had mobilization of the urethral plate and proximal normal urethra for penile straightening. Further analysis of those patients undergoing this dissection to correct penile curvature without transecting the urethral plate showed that nearly 20% developed focal, symptomatic strictures that did not occur in proximal TIP repairs without dissection under the urethral plate and urethra, and so that maneuver is no longer performed or recommended.
A meta-analysis of TIP complications that included primary distal and proximal, and reoperative, series reported the mean percentage of reported urethral strictures was 1.3, 2.0, and 3.0, respectively.
After 2-Stage Graft Repairs
Urethral strictures after primary 2-stage graft procedures, mostly using prepuce, did not occur in any patient in a series of 34 boys reported by Ferro and colleagues or in the authors’ series of 55 consecutive cases of severe hypospadias, defined as having ventral curvature greater than 30° after degloving.
The authors also reported no urethral strictures in 45 patients undergoing 2-stage oral mucosa graft salvage repairs of hypospadias cripples, defined as patients undergoing reoperation for ventral curvature greater than 30°, grossly scarred urethral plate or skin, hairy neourethras, obliterative strictures or meatal stenosis, and/or balanitis xerotica obliterans. Another similar series found urethral strictures in 16%, but did not further describe this observation, which may have included meatal stenosis.
The low prevalence of strictures in TIP and 2-stage graft repairs suggests a higher incidence of technical error.
Prevalence
Fifteen years ago, during the peak of preputial flap hypospadias repairs, urethral strictures were reported as a common complication, occurring in approximately 8% of cases. For example, Duel and colleagues found 38 (7%) of 582 repairs resulted in a stricture following a variety of mostly skin flap or skin graft operations for predominantly proximal hypospadias. Weiner and colleagues found strictures in 9% of patients after tubularized preputial flap repair, versus none using onlay preputial flaps. Two series of Byars’ preputial flap repairs published this year reported urethral strictures in 8% and 12%.
After Tubularizing the Urethral Plate
In contrast, procedures tubularizing the urethral plate (TIP) or a graft neoplate (2-stage preputial or oral mucosa graft repairs) have almost anecdotal prevalences of urethral strictures. For example, the authors reported no strictures in 426 consecutive distal hypospadias repairs with follow-up, all corrected using TIP. They subsequently published urethral stricture occurring in 1 of 24 patients with proximal TIP who had mobilization of the urethral plate and proximal normal urethra for penile straightening. Further analysis of those patients undergoing this dissection to correct penile curvature without transecting the urethral plate showed that nearly 20% developed focal, symptomatic strictures that did not occur in proximal TIP repairs without dissection under the urethral plate and urethra, and so that maneuver is no longer performed or recommended.
A meta-analysis of TIP complications that included primary distal and proximal, and reoperative, series reported the mean percentage of reported urethral strictures was 1.3, 2.0, and 3.0, respectively.
After 2-Stage Graft Repairs
Urethral strictures after primary 2-stage graft procedures, mostly using prepuce, did not occur in any patient in a series of 34 boys reported by Ferro and colleagues or in the authors’ series of 55 consecutive cases of severe hypospadias, defined as having ventral curvature greater than 30° after degloving.
The authors also reported no urethral strictures in 45 patients undergoing 2-stage oral mucosa graft salvage repairs of hypospadias cripples, defined as patients undergoing reoperation for ventral curvature greater than 30°, grossly scarred urethral plate or skin, hairy neourethras, obliterative strictures or meatal stenosis, and/or balanitis xerotica obliterans. Another similar series found urethral strictures in 16%, but did not further describe this observation, which may have included meatal stenosis.
The low prevalence of strictures in TIP and 2-stage graft repairs suggests a higher incidence of technical error.
Diagnosis
Strictures are most often diagnosed due to symptoms, including stranguria, urinary retention, and urinary tract infection, following hypospadias surgery. It is unusual to diagnose strictures in asymptomatic children, for example, on the basis of flow rate parameters alone.
Uroflowmetry
Uroflowmetry was once recommended after hypospadias repair specifically to detect asymptomatic strictures. However, although Garibay and colleagues emphasized a need for uroflowmetry after hypospadias repair, stating only 30% of patients diagnosed with obstruction had symptoms, only 2 of these patients had urethral strictures requiring repair. It is not clear from their article if these 2 had symptoms or not.
Meanwhile, studies of uroflows in patients with unoperated hypospadias report many have a Qmax around the fifth percentile of nomogram values and a plateau curve, likely indicating the formed urethra is also abnormal. Therefore, postoperative uroflometry with low Qmax and a plateau curve does not necessarily result from stricture, especially if the patient is otherwise asymptomatic.
Accordingly, many investigators have stated that uroflow parameters alone are not an indication for invasive urethral studies. The fact that Qmax tends to improve with time supports observation in asymptomatic patients with “obstructive” flow parameters after hypospadias repair. This improvement in teens also argues against an increased risk for structuring during puberty.
Urethrography
Although an occasional patient with a stricture after hypospadias repair has a bulbar lesion, most often the obstruction is within the neourethra or at its junction to the native urethra. Although urethrography can be done, the relatively short distance from meatus to lesion in children, in contrast to adults, and the difficulty in holding the catheter in place while occluding the meatus in a moving child, who likely needs sedation, argues against this study. The authors never obtain this imaging.
Urethroscopy
Diagnosis of anatomic obstruction in children after hypospadias surgery is best done under general anesthesia, which facilitates accurate calibration of the neomeatus to rule out stenosis (<8 French), and urethroscopy to visualize a stricture.
Management
Dilations
There is no role for therapeutic dilations to manage urethral strictures in children.
Visual Urethrotomy
A protocol was followed to assess efficacy of visual urethrotomy (VU) to manage urethral strictures less than 1 cm in length after prior hypospadias surgery, with several important observations derived from a series of 72 patients. Overall success, defined as symptom free at a minimum of 2 years of follow-up, with Qmax greater than 12 mL/s, was 24%.
Outcomes depended on the type of prior repair, with no success in 32 patients with tubularized grafts and 11% success in 18 with tubularized preputial flaps. In contrast, VU was successful in 72% of 11 with onlay preputial flaps and 63% of 11 with tubularized urethral plates.
Repeat VU was only done for recurrent strictures thought to still be less than 1 cm, with few successes (2/25) and nearly universal increase in subsequent length of the stricture. Rather than repeat VU, open urethroplasty was recommended for all recurrent strictures, even those still less than 1 cm.
Two other retrospective reviews of VU for posthypospadias repair strictures also reported that repeat VU was not effective. Therefore, if VU is selected for initial treatment of a posthypospadias repair stricture and is not successful, open urethroplasty should next be done.
Urethroplasty
Excision with anastomosis
The authors are not aware of published series regarding stricture excision with end-to-end anastomosis for lesions developing after hypospadias repair. They assume vascularity of neourethras is not as reliable as that of otherwise normal urethras affected by strictures and avoid this procedure, as do others.
Instead, the authors choose between 1-stage dorsal oral mucosa graft inlay and 2-stage oral mucosa graft replacement urethroplasty for stricture repair.
One-stage graft inlay
Nonobliterative strictures usually can be corrected with a 1-stage inlay graft. Urethroscopy first confirms the stricture and its location. The meatus and neourethra distal to the stricture are calibrated to ensure normal caliber, which in children is greater than 8 French. Then, a ventral midline incision is made in the raphe. It is not necessary to deglove the penis.
The neourethra is opened ventrally proximal to the stricture and is then incised distally through the stricture and beyond a short distance, laying the stricture entirely open. If the stricture extends into the glans, then glans wings are developed and the neourethra is opened until healthy tissue is encountered or the meatus is open. Next, the dorsal midline of the neourethra and stricture is incised through the urethral wall, stopping just above the tunica albuginea of the corpora cavernosa. A 7-0 polydioxanone stay suture in the outer edge of the neourethra on each side holds the dorsal defect open until the graft is placed.
The defect is measured, and a graft of similar dimension is outlined on the inner surface of the upper lip, near the teeth. An inlay graft should not be taken from the lower lip, saving that site should recurrent stricture require a replacement urethroplasty. The mucosa is injected with bupivacaine mixed with 1:200,000 epinephrine, and then the borders of the graft are incised, beginning near the gums so that blood running down does not obscure the dissection. Next, the mucosa is dissected from the underlying fatty tissues and muscle, leaving behind as much fatty tissue as possible.
The authors leave gauze soaked in 1:1000 epinephrine against the harvest site. This gauze is removed at the end of the case, with additional hemostasis achieved using electrocautery as needed at that time. The donor site should not be sutured, but is left open for healing by secondary intention.
The graft is defatted. Larger grafts are best draped over the surgeon’s finger to feel the pressure and depth of dissection. Smaller grafts will lay still for defatting by simply placing them onto a wet spot on the paper drape.
Then, the graft is sutured into the defect, beginning proximally and continuing with interrupted 7-0 polyglactin epithelial sutures around the perimeter distally. Both the proximal and the distal ends of the graft should enter well into normal neourethra beyond the stricture to reduce likelihood for recurrence.
The graft is finally quilted in the midline to secure it to the underlying corporal surface, using 7-0 polyglactin. The graft should be wide enough to stretch across the defect and affix to the corpora without tension; otherwise, the gain in width may not be sufficient.
A 6-French catheter is passed into the bladder. The ventral urethra is sutured using subepithelial stitches in 2 layers, as in a primary hypospadias urethroplasty. A flap of ventral dartos tissues is raised proximally and flipped up and over the entire repair to reduce risk for fistula. If there is not sufficient grossly healthy dartos, a tunica vaginalis flap can be harvested for a barrier layer.
Skin closure is done using interrupted subepithelial polyglactin. The catheter provides urinary diversion for approximately 10 days.
Related posts:
Management of Urethral Strictures
Definition of Successful Treatment and Optimal Follow-up after Urethral Reconstruction for Urethral Stricture Disease
Cost-effective Strategies for the Management and Treatment of Urethral Stricture Disease
The Nontransecting Approach to Bulbar Urethroplasty
Management of Panurethral Stricture
Effect of Lichen Sclerosis on Success of Urethroplasty
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