12. Predictors of Urethral Stricture Recurrence After Urethroplasty
KeywordsPredictorsUrethral strictureRecurrenceFailureUrethroplastyTreatment outcomes
Urethroplasty remains the gold standard for the management of urethral stricture offering the highest success rates and in some instances the most cost-effectiveness compared to repeat direct vision internal urethrotomy (DVIU) or dilation. Although urethroplasty is considered a highly successful and durable treatment, one must remain vigilant for stricture recurrences which can occur many years after surgery. However, the factors that lead to urethroplasty failure are poorly understood. In this chapter, we would like to discuss about the predictors of stricture recurrence after urethroplasty.
12.1 Urethral Stricture Recurrence Rates
Although the modality for recurrence surveillance after urethroplasty remains widely variable, lifetime success rates range from 75% to 100% . Many studies are heterogeneous with variable stricture location, length, etiology, and reconstructive techniques. Given this variability, it is hard to compare studies, techniques, and outcomes. Also, it is hard to draw meaningful conclusion about the predictors of stricture recurrence after urethroplasty from the existing literature.
12.2 Common Predictors of Stricture Recurrences
Traditionally, common predictors for stricture recurrence include stricture location, length, prior DVIU or urethroplasty, age and so on. These predictors can be categorized as stricture-related, patient and operator factors (Table 12.1).
Common predictors of urethral stricture recurrence after urethroplasty
Comorbidities (obesity, diabetes mellitus, hypogonadism)
Selection of appropriate surgical procedure
Surgical learning curve
12.2.1 Stricture-Related Factors
22.214.171.124 Stricture Location
Urethroplasty for penile urethral stricture , often because of poor tissue quality, is technically more challenging than bulbar urethral surgery and the results have been reported to be less satisfactory . Meeks et al.  conducted a systematic review of 302 articles publications from 2000 to 2008 which included 5617 urethroplasties to identify stricture recurrence rate after urethroplasty. They identified that penile stricture had a higher rate of recurrence (18.4%) compared to bulbar stricture (13.9%). To evaluate the learning curve of urethroplasty, Faris et al.  analyzed 613 urethroplasty cases from six surgeons. The success for bulbar urethroplasty was higher than for penile urethroplasties (88.2% vs. 78.3%). There was a statistically significant trend toward improved outcomes with increasing number of cases, which was most pronounced with bulbar repairs. There was no statistical improvement in penile repairs over time.
126.96.36.199 Stricture Length
Previous studies have reported stricture length greater than 4 cm to be a risk factor for surgical failure [4, 5]. In a systematic review by Meeks et al. , the recurrence rate was significantly higher for longer strictures (≥5 cm, 16.6%) compared to that for shorter strictures (<5 cm, 12.4%). Kinnaird et al.  conducted a retrospective review of 604 urethroplasties to determine the risk factors for stricture recurrence. Strictures of ≥5 cm were found to increase recurrence from 6% to 14%. In a small series with 40 patients, the success rate is significantly lower in strictures longer than 7 cm (stricture-free rate; 88% vs. 40% at 43.4 months follow-up) and panurethral strictures .
188.8.131.52 Prior DVIU
Many nationwide surveys regarding practice patterns of urethral stricture showed similar results that most urologists had little experience with urethroplasty while DVIU or dilation were often performed despite of limited success rate [8–11]. However, repeated DVIU can increase the length and density of spongiofibrosis, thus making definitive surgical intervention more difficult . Clinical guidelines state that the indication for DVIU/dilation as first line therapy should be limited to strictures with favorable characteristics and repeated DVIU/dilation should be avoided because of low efficacy and increasing spongiofibrosis [13, 14]. Especially, a third DVIU/dilation is not recommended, except if necessitated by patient comorbidities or economic resources .
Greenwell et al.  reported that repeat DVIU or dilation for the treatment of urethral stricture is neither clinically effective nor cost-effective. Many other studies also demonstrated that repeat transurethral manipulation is associated with increased stricture complexity and recurrence rate [4, 11, 16, 17]. Hudak et al.  divided 101 cases with bulbar urethral stricture into 2 groups based on the history of transurethral treatment before urethroplasty; group 1-0 or 1 and group 2-2 or greater treatments. The authors concluded that repeat transurethral manipulation of bulbar strictures is associated with increased stricture complexity and a marked delay (eight-fold) to curative urethroplasty.
184.108.40.206 Lichen Sclerosus
Strictures due to lichen sclerosis most primarily affect the penile urethra and tend to be longer. Concerning lichen sclerosus, the success rate of urethral repair is significantly lower for patients with the skin disease than without the inflammatory condition. Erickson et al.  analyzed data from 1151 men who underwent urethroplasty from their multi-institutional database. Patients with lichen sclerosis had average longer strictures, mostly involving the penile urethra and rarely the bulbar urethra alone. Substitution urethroplasty had a significantly lower success rate than strictures due to other causes (82% vs. 92%). In addition, a significantly higher rate of chronic, systemic inflammatory conditions, such as hypertension, diabetes, and obesity, was noted in the lichen sclerosus patients compared with patients without the condition.
12.2.2 Patient Factors
Elderly men commonly undergo urethral instrumentation and transurethral treatment of benign prostatic hyperplasia. Consequently, the incidence of urethral stricture is greatest in the aging population . On multivariate analysis of 443 patients who underwent urethroplasty, age (older than 65 years) was not predictive of surgical failure . To determine if age is an independent predictor of surgical success in patients undergoing urethroplasty, study outcomes were compared between 2 age groups (<60 years old and ≥60 years old) . Of 322 urethroplasties, 258 were performed in patients <60 years and 64 in patients ≥60 years. There was no difference in need for repeat procedures or anatomic recurrence between age groups or with increasing age. Recently, Viers et al.  reported the largest single-institution series to evaluate surgical outcomes of urethroplasty in aging men. Among 514 urethroplasty procedures, 184 (36%) were evaluated in men ≥60 years. The estimated 60-month stricture recurrence-free survival decreased with increasing age at time of urethroplasty. Of course, age alone should not be used as a contraindication to urethroplasty, however, it should be noted that comorbidities are common in aging men [20, 21]. In addition, it should be kept in mind that voiding dysfunction and prostatic obstruction are common in this population.
Current smoking predicted increased risk of stricture recurrence on multivariate analysis of 443 patients (hazard ratio 1.8) . However, smoking was not associated with recurrence in other studies [6, 20, 22].
Obesity is a global epidemic. Obesity is associated with an impaired immune response, which likely contributes to the increased rate of surgical site infection, a well-known cause for surgical failure of urethroplasty [23, 24]. In addition, obesity patients often have comorbidities such as cardiovascular disease that also can affect surgical outcomes . In a retrospective review of 15 obese men with body mass index (BMI) >35 mg/m2, obese men demonstrated poorer outcomes after grafted bulbar urethroplasty when compared with published success rates in the general population as well as an aged-matched, nonobese cohort from authors’ institution . Similarly, on multivariate analysis of 596 patients who underwent bulbar urethroplasty, obesity (BMI ≥35 mg/m2) was associated with stricture recurrence (hazard ration 2.9) . Breyer et al.  demonstrated that patients who are overweight (BMI 25–30 kg/m2) and obese (BMI 30–35 kg/m2) develop urethroplasty failure more frequently, however, the severely and morbidly obese did not. The authors hypothesize that this non-linear relationship between BMI may relate to the more sedentary status of the morbidly obese patient and that this protects against activities that may put their urethroplasty at risk of failure (‘obesity paradox’) . In a recent retrospective review of 137 patients, BMI did not independently predict for stricture recurrence following urethroplasty .
On multivariate analysis of 381 patients who underwent urethroplasty and had complete BMI data, diabetes mellitus was a significant negative influence on urethroplasty outcome . In another review by Breyer et al. of 443 patients, diabetes was associated with an increased risk of stricture recurrence (hazard ratio 2.0), though it was not statistically significant . In this study, diabetes appears to be under reported. Diabetes is known to cause microvascular damage which could impede healing after urethroplasty and promote stricture recurrence. However, research on this subject is very limited.
Recently, Spencer et al.  reported that hypogonadism is more prevalent and associated with increased disease severity in men with urethral stricture. Age, diabetes and obesity, potential predictors for stricture recurrence, are also associated with hypogonadism . Therefore, further studies are needed on this subject.
12.2.3 Operator Factors
In fact, the ability of the operator might be the most important factor to determine the success rate of the urethroplasty. In a retrospective review of 90 patients with penile stricture undergoing 109 open urethroplasties, there was a significant decrease in failure rate when comparing the first consecutive 55 cases to the last 54 cases . The authors suggested that surgeon’s experience and probably the selection of an appropriate method seem to be paramount importance for success of urethroplasty. A total of 613 urethroplasty cases from six surgeons were analyzed . Overall success rates improved significantly with time (surgeon experience), and proficiency (defined as >90% success) occurs after approximately 100 cases. In a single-surgeon (Guido Barbagli) analysis of 641 patients treated with one-stage urethroplasty, surgeon experience was significantly associated with a lower probability of treatment failure (hazard ratio per 20 procedures: 0.98) . The surgical learning curve appeared lengthened, without reaching a plateau even after 600 procedures.
12.3 Predictors of Stricture Recurrence for Each Procedure
The management of urethral stricture disease in adult males has a wide range of possible therapeutic options. These predictors can be determined according to anatomic location and type of urethroplasty (Table 12.2).
12.3.1 Bulbar Urethral Stricture
220.127.116.11 Excision and Primary Anastomosis
For short bulbar urethral stricture , excision and excision and primary anastomosis (EPA) remains the ideal procedure with excellent long-term results. A total of 17 level 3 evidence series with >10 patients were included for analysis, and the composite success rate reported among 1234 men having EPA for bulbar urethral strictures was 93.8% . In general, the best stricture length manageable by EPA is 2 cm or less, however, strictures longer than 2 cm can be managed successfully in selected patients with EPA [34–36]. Morey and Kizer  reported on a selected cohort of 22 patients with proximal bulbar urethral strictures longer than 2.5 cm that were treated with an extended anastomotic approach and suggested that the ability of the urethra to be reconstructed is proportional to the length and elasticity of the distal urethral segment.
Predictors of stricture recurrence for each urethroplasty procedure
Bulbar urethral stricture
Excision and primary anastomosis (EPA)
Prior treatments (multiple dilations, DVIU or urethroplasty) 
Ventral onlay urethroplasty
Qmax <7 ml/s 
Dorsal onlay urethroplasty (no data found)
Two-sided onlay urethroplasty
Stricture length (≥4 cm) 
Augmented anastomotic urethroplasty
Age (older patients) 
Urinary tract infection 
Stricture length 
Penile urethral stricture
Dorsal inlay urethroplasty (Asopa technique) (no data found)
One-sided dorsolateral onlay urethroplasty (Kulkarni technique) (no data found)
Penile circular fasciocutaneous (McAninch technique) – onlay variant
Previous hypospadias repair 
Stricture length (>7 cm) 
Pen. circ. fasciocut. (McAninch technique) – tubed variant (no data found)
Urethroplasty after PFUI
Type of fracture (vertically unstable and/or rotationally unstable)
Displacement of inferior medial pubic bone
Symphysis pubic diastasis
Timing of management (early endoscopic realignment/open recons.)
Severity of injury (defect length and type)
Prior therapeutic history (revisional surgery and repeated DVIUs)
Incomplete excision of scar tissue during surgery
The impact of previous treatment on surgical outcomes is controversial. In 2 large series of EPA reported by Santucci et al.  and Eltahawy et al. , 55% and 69.2% of patients had a history of failed attempts of urethroplasty or DVIU , respectively, and despite this, surgical outcomes were equally excellent. By contrast, in the study by Barbagli et al. , the only group of patients who had a lower success rate (78.6%) had undergone multiple treatments (dilation, DVIU, or urethroplasty), whereas the other groups (prior single or no treatment) showed similar success rates ranging from 92.1% to 100% without any statistical significance.
There is no clear consensus on stricture etiology and the success rate with respect to EPA. However, it is generally accepted that traumatic stricture due to perineal straddle injury is best treated by EPA. Suh et al.  reported that the recurrence rate was significantly higher in patients with nontraumatic causes (26.7%) than in the patients with traumatic cause (0%). The authors suggested that the most likely reason for the better results in the traumatic group is that spongiofibrosis developed from outside to inside, which makes it easier to identify the extent of stricture. On the contrary, spongiofibrosis propagated from inside to outside in urethral strictures of nontraumatic causes, especially those with iatrogenic or infectious causes. Therefore, the surgeon should convert an EPA to augmented anastomotic urethroplasty without hesitation if there is any concern about inadequate excision of unhealthy tissue.
18.104.22.168 Substitution Urethroplasty
Ventral and dorsal onlay urethroplasties are the most popular types of substitution urethroplasty . In a meta-analysis, buccal mucosa graft (BMG) had the highest success rate (88.1%) and the success rate was similar between the ventral and dorsal onlay techniques (87.6% vs. 89.2%) . In a systematic review, there was no difference in the success rate of a ventral and dorsal onlay technique for the bulbar stricture (88.8% vs. 88.4%) . However, ventral onlay urethroplasty is usually carried out only for midbulbar and proximal bulbar stricture, where the thick spongiosum provides excellent blood support for the graft. In addition, most reconstructive surgeons prefer dorsal onlay BMG instead of ventral BMG urethroplasty if there is significant spongiofibrosis. Therefore, comparisons of surgical outcomes between ventral and dorsal BMG onlay urethroplasty are limited by selection bias.
Ventral Onlay Urethroplasty
In a retrospective study of 214 patients who underwent ventral onlay urethroplasty with BMG for bulbar urethral stricture , the success rate was 85.5% with median follow-up of 54 months . The preoperative maximum flow rate (Qmax) was a significant predictor of surgical outcome. Patients with a preoperative Qmax 7 ml/s have more than a threefold higher success rate compared with patients with a preoperative Qmax <7 ml/s. However, age, length, and type of stenosis, and previous treatment were not significant predictors of surgical outcome.
Dorsal Onlay Urethroplasty
Barbagli et al.  reported the 80.2% long-term success rate in 81 patients for dorsal onlay bulbar urethroplasty using BMG. A total of 359 patients who underwent substitution urethroplasty were included in study. Substitute tissue type (oral mucosa vs skin) was the only significant predictor on multivariate analysis.
Two-Sided Onlay Urethroplasty (Palminteri Technique)
In a single-center retrospective study of 166 patients who underwent 2-sided dorsal plus ventral BMG urethroplasty by preserving the narrow urethral plate in tight bulbar strictures, success rate was 89.8% with a median follow-up of 47 months . The stricture length (≥4 cm) was a significant predictor of stricture recurrence ; however, age, stricture etiology, and previous treatment were not significant predictors of surgical outcome.
22.214.171.124 Augmented Anastomotic Urethroplasty
Guralnick and Webster  introduced the term ‘augmented anastomotic urethroplasty (AAU) ’ to describe a hybrid procedure combining elements of the EPA and substitution urethroplasty. Abouassaly and Angermeier  reported their experience of AAU in 69 patients with a success rate of 90% at a mean follow-up of 34 months. In 58 patients (84%) the graft was placed ventrally, whereas in 11 (16%) it was placed in the dorsal position. They found that recurrence tended to occur in older patients and in those with postoperative urinary tract infection. Hoy et al.  reported the results of 163 patients who underwent dorsal onlay AAU with BMG. The success rate was 96.9% with a median follow-up of 31 months. They suggested that strictures longer than 5 cm are amenable to repair using this technique, but are prone to recurrence. El-Kassaby et al.  reported the largest series using AAU with ventral BMG onlay. The success rate was 93.7% in 233 patients with a mean follow-up of 36 months. There was no comment on potential risk factors for recurrence.
12.3.2 Penile Urethral Stricture
126.96.36.199 Substitution Urethroplasty
Dorsal Inlay Urethroplasty (Asopa Technique)
There have been limited data about the surgical outcomes of Asopa’s ventral sagittal urethrotomy and dorsal inlay urethroplasty [48, 49]. The main advantage of the Asopa technique is that it is easy to perform and has no need to urethral mobilization. The main drawback is that the augmentation of the Asopa technique is less wide than that can be achieved with the dorsal onlay technique. Additionally, it is best to perform this technique when the urethral plate is not too narrow (≥1 cm in width) .
One-Sided Dorsolateral Only Urethroplasty (Kulkarni Technique)
Kulkarni et al.  developed a new one-sided anterior dorsal BMG urethroplasty while preserving the lateral vascular supply to the urethra. Kulkarni et al.  presented their experience with this technique in 117 patients with panurethral stricture. The overall success rate was 83.7% with a success rate of 86.5% for primary urethroplasty and 61.5% in patients in whom urethroplasty had previously failed.
188.8.131.52 Flap Urethroplasty
Ventrally placed circular penile fasciocutaneous flap described by McAninch is likely to be the most useful technique, with excellent cosmetic and functional results . The benefits of this procedure include its hairless nature, sufficient length (13–15 cm), flexibility, and versatility . However, it should be used as an onlay rather than tubularized flap because of high risk for restenosis . For urethral stricture secondary to lichen sclerosus, genital skin should not be used when reconstruction is performed . Whitson et al.  reported the long-term efficacy of distal penile circular fasciocutaneous flap for single-stage urethroplasty in 124 patients with complex anterior urethral strictures. At 1, 3, 5, and 10 years, the overall estimated stricture-free survival rates were 95%, 89%, 84%, and 79%, respectively. On multivariate analysis smoking (hazard ratio 4.0), history of hypospadias repair (hazard ratio 4.4) and stricture length 7–10 cm (hazard ratio 7.0) were predictive of failure.
12.4 Urethroplasty for Pelvic Fracture Urethral Injuries
Basically, the term urethral stricture refers to anterior urethral disease by consensus of the World Health Organization conference . In contrast, posterior urethral ‘strictures’ are not included in the common definition of urethral stricture. Pelvic fracture urethral injuries (PFUI) are injuries to the urethra that result from disruption of the pelvic ring. The term ‘pelvic fracture urethral distraction defect’ has therefore been discontinued and replaced by PFUI, because a large percentage will be partial injuries and even complete ruptures will not always present as a separation of the urethral ends . Subsequent narrowings of the posterior urethra are termed as urethral stenosis.
12.4.1 Issues of Immediate Management
One of the most debatable issues in the treatment of PFUI patients is whether to perform endoscopic primary realignment or delayed urethroplasty after suprapubic cystostomy. Most surgeons favor the delayed reconstruction because urethral stenosis or complete obliteration of lumen is almost inevitable after primary realignment, and primary realignment may lead to additional urethral trauma, even may worsen the prognosis after delayed urethroplasty [57–59]. Singh et al.  reported that endoscopic primary realignment or immediate primary urethroplasty significantly decrease the success of subsequent anastomotic urethroplasty. Tausch et al.  also reported that compared to delayed urethroplasty, primary realignment often appears to be associated with a complex and prolonged treatment course for men with PFUI. Primary realignment was not associated with shorter strictures or easier urethroplasty, and it is reported to have prolonged clinical course and time to urethroplasty [59, 62]. On the other hand, it has been also suggested that primary realignment may reduce risk of subsequent urethral stenosis and obliteration. Primary realignment may also obviate the need for urethroplasty in some cases and does not increase complications rates [62–64]. Recent systematic review demonstrated that about half of the patients were free of stenosis or obliteration and thus did not undergo urethroplasty in case primary realignment had been performed . However, they also commented that this study was limited by a high degree of bias due to the heterogeneous population.
The main problems about these issues have been the lack of any randomized studies with comparable groups of patients in comparable situations and the lack of a defined outcome or endpoint [56, 64]. In practice it is clear that primary realignment is usually reserved for those with less serious injuries. Currently, ongoing prospective multi-institutional cohort study would determine the utility of primary realignment after PFUI . The AUA guideline in the urotrauma section summarized that clinicians may perform primary realignment in hemodynamically stable patients with PFUI, but prolonged attempts must be avoided as the process may increase injury severity and long-term sequelae . Immediate open repair was associated with significant morbidity including the greater incontinence and impotence rates . Currently, the main indications for immediate open repair are penetrating injuries, injuries of the bladder neck and prostate, injuries associated with perineal degloving and injuries associated with a rectal injury (Table 12.3) .