End-to-end urethroplasty: long-term results

The urinary and sexual outcomes of buccal mucosal graft urethroplasty versus end-to-end anastomosis: a systematic review with meta-analysis

Background

The urinary and sexual outcomes after urethroplasty may be a concern for patients, but there are still some controversies regarding the consequences of buccal mucosal graft urethroplasty (BMG) in terms of erectile dysfunction (ED).

Aim

This meta-analysis aimed to compare urinary and sexual outcomes of BMG and end-to-end urethroplasty (EE).

Methods

The PubMed, Web of Science, Cochrane, and Embase databases were searched until February 31, 2023. Data extraction and quality assessment were performed by 2 designated researchers. Dichotomous data were analyzed as odds ratios with 95% confidence intervals (CIs). Heterogeneity across studies was assessed by the I2 quantification, and publication bias using Begg's and Egger's tests. Meta-analysis was performed using RevMan software.

Outcomes

Outcomes included stricture recurrence, ED, penile complications, and voiding symptoms.

Results

Eighteen studies, including 1648 participants, were included in our meta-analysis. The meta-analysis revealed that there was no significant difference in stricture recurrence (OR = 0.74; 95% CI, 0.48-1.13; P = .17) and voiding symptoms (OR = 1.12; 95% CI, 0.32-3.88; P = .86) between the BMG group and the EE group. BMG was associated with lower risk of penile complications (OR = 0.40; 95% CI, 0.24-0.69; P = .001) and ED (OR = 0.53, 95% CI, 0.32-0.90, P = .02).

Clinical Implications

The study may help clinicians choose procedures that achieve better recovery of the urological and sexual function in the treatment of urethral stricture.

Strengths and Limitations

This meta-analysis is the first to evaluate the urinary and sexual outcomes of BMG vs EE. A limitation is that most of the included studies were retrospective cohort studies.

Conclusion

BMG is as effective as EE in the treatment of bulbar urethral stricture, but BMG has fewer complications and ED than EE.

Timing of Urinary Catheter Removal After Urethroplasty: A Systematic Review

OBJECTIVE

To synthesize existing evidence to evaluate the outcomes of different urinary catheter removal timing (early vs late) after urethroplasty.

METHODS

We performed a comprehensive search of PubMed, Embase, the Cochrane Library, and Web of Science from inception to August 7, 2022. Articles were initially screened by title, abstract, and subsequently by a full paper review before being included in the final analysis. All comparative studies that assessed the association between urethral catheterization duration and frequency of extravasation and recurrence rate in patients who underwent urethroplasty were included in the analysis. Exclusion criteria were case reports, case series, letters to editors, and non-English studies. The risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

Of the 439 relevant records in the literature databases, 5 studies involving 634 patients were included. In all 5 studies, the extravasation rate was not significantly different between the early and late catheter removal groups. Among the 3 studies that reported recurrence rates, the recurrence rate was low, with no statistically significant difference between the early and late catheter removal groups. Wound and urinary tract infections were among the most common complications, with a higher rate in patients with late catheter removal.

CONCLUSION

Early catheter removal following urethroplasty does not increase the rate of extravasation or recurrence during long-term follow-up. The existing evidence can serve as the foundation for additional research with a larger sample size.

Outcomes and predictive factors for re-stricture with urethroplasty methods for anterior urethra stricture

OBJECTIVES

We wished to compare the treatment success of urethroplasty methods (EPA and BMG) used for anterior urethra stricture after unsuccessful internal urethrotomy.

METHODS

A total of 85 and 51 patients, respectively, who underwent excision and primary anastomosis (EPA) and buccal mucosal graft (BMG) urethroplasty due to recurrent strictures after direct vision internal urethrotomy (DVIU) were evaluated retrospectively. On the uroflowmetry test, >15 ml/s urine flow and residual urine (PVR) below 50 ml were determined as success criteria. Cox regression analysis investigated the probable predictive factors for surgery success. Kaplan-Meier analysis assessed stricture free survival after redo-urethroplasty.

RESULTS

After surgery, EPA and BMG patients were followed for 31.9 ± 9.8 (4-40) and 30.7 ± 10.3 (4-40) months. At the end of this follow-up duration, success was obtained for 71 (83.5%) and 44 (86.3%) patients. Mean re-stricture times were 13.9 ± 6.0 (4-19) and 10.2 ± 5.1 (4-26) months. Most re-strictures had penile location (10 (71.5%) and 7 (100%)). After one session of DVIU, there was 100% success in both groups, but after >3 sessions of DVIU, success fell to 70.3% and 78.3% in the groups respectively. Patients with high numbers of DVIU sessions had longer durations for urethroplasty surgery. Apart from complications related to the donor field in the oral region with BMG and four patients who developed fistula (7.8%), complications were similar in both groups.

CONCLUSIONS

In this series of cases, it was not possible to identify which of the techniques employed provides the best result or predictive factors for stenosis recurrence after correction procedures for anterior urethral stenosis.

Significance of inflammatory biomarkers and urethral histology in patients with urethral stricture disease in relation to treatment outcome—a single centre prospective study in the north-eastern part of India

Background

Inflammation plays a very important role in defining the urethral stricture. Inflammatory biomarkers may play an important role in predicting the underlying pathophysiology as well as outcome of surgery. Histology of urethral strictures along with histology of urethra proximal and distal to stricture segment may have a role in predicting the outcome of the surgery. The literature discussing this aspect is rare; thus, this novel study aimed to find out the role of inflammatory biomarkers and urethral histology in predicting the outcome of surgery in urethral stricture disease.

Methods

This prospective study had 105 patients with age more than 15 years with urethral stricture. Baseline characteristics, routine blood tests including inflammatory blood markers (CRP, ESR, HbA1C, fasting insulin, serum ferritin, etc.) were recorded. They underwent various types of surgery, and first biopsy was taken from stricture segment and second biopsy from proximal to stricture segment and third biopsy from distal to stricture segment and evaluated for the presence of features of lichen sclerosus and inflammation. Primary endpoint was to diagnose the role of inflammatory biomarkers and histology of stricture in stricture recurrence.

Results

Their mean age was 43.3 ± 13.46 years. Mean CRP of 11.54 ± 3.64 in patients with failure and 9.59 ± 2.77 in patients with successful outcome (p 0.025). Other inflammatory biomarkers like HbA1C, fasting insulin, ESR, serum ferritin, NLR had no significant correlation with the outcome. The presence of features of lichen sclerosus like hyperkeratosis and severe inflammation in stricture segment predicted higher likelihood of failure. Histology of proximal and distal segment of urethral stricture had no significant relationship in predicting outcome. Staged urethroplasty with buccal mucosal graft outperformed single-stage urethroplasty in biopsy-proven LS strictures.

Conclusions

The present study found a negative impact of increased CRP and the presence of features of lichen sclerosus in urethral histology with the outcome of urethral stricture disease. Thus, our study confirms that inflammatory biomarkers (CRP) and histology of stricture segment play a significant role predicting the outcome of surgery.

Anterior Urethroplasty for the Management of Urethral Strictures in Males: A Systematic Review

OBJECTIVE

To identify the currently utilised techniques of anterior urethroplasty described in literature for treatment of urethral strictures, assess the effectiveness of the identified techniques based on re-stricture and complication rates, evaluate, and suggest treatment options based on current evidence for urethral strictures at different locations and of different lengths.

METHODS

A systematic review of the MEDLINE, EMBASE, Scopus and Cochrane Library databases from conception up to September 2020 was performed. Primary outcomes included success rates measured via re-stricture rates and the post-operative maximum urinary flow rate (Qmax). Secondary outcomes included patient reported complication rates.

RESULTS

A total of 52 papers, including 7 RCTs, met the inclusion criteria. Forty studies described the use of free graft urethroplasty with a median success rate of 86.5% (IQR = 8.1). The best outcomes were found in dorsal onlay buccal mucosa grafting in the penile urethra (86.6%). Twelve described the use of pedicled flap urethroplasty with a median success rate of 76% (IQR = 14.4). Excision and Primary Anastomosis results were reported in 5 studies and showed an overall highest success rate of 89.7% (IQR = 7.0) but involved the shortest strictures of median lengths of 2.1 cm (IQR = 0.48).

CONCLUSION

Graft urethroplasty showed optimal outcomes when utilised in penile and bulbar strictures, with dorsal onlay buccal mucosa grafting presenting with the largest evidence base and best outcomes overall. Flap urethroplasty had the highest success rates in panurethral and bulbar strictures, while anastomotic urethroplasty had the greatest success in bulbar and penobulbar strictures.

Estado de la urología reconstructiva en Colombia: Tratamiento de la estrechez uretral anterior, una encuesta nacional

Purpose El tratamiento mínimamente invasivo de la estrechez uretral tiene altas tasas de recurrencia y re-operación a largo plazo, no obstante, encuestas realizadas en otros países han demostrado que los urólogos tienen poca experiencia con la uretroplastia abierta y hay una preferencia a la utilización de las terapias endoscópicas mínimamente invasivas. El objetivo de este estudio, es describir patrones de práctica del tratamiento de la estrechez de uretra anterior en nuestro país.

Métodos Se trata de un estudio observacional descriptivo y para ello se realizó un cuestionario adaptado a nuestro contexto nacional, basado en varios estudios previamente realizados acerca de la experiencia en Urología reconstructiva. Ese cuestionario incluía información sobre la edad, nivel de experiencia en urología general, la experiencia en urología reconstructiva, escenario de la práctica y las técnicas preferidas para el manejo de las estrecheces uretrales pendulares y bulbares. La información fue almacenada de forma anónima, los datos fueron analizados mediante el paquete estadístico SPSS y se realizó un análisis de distribución de frecuencias.

Resultados Se obtuvieron 106 respuestas de los urólogos encuestados. Para el tratamiento de la estrechez uretral pendular la mayoría de los urólogos prefiere el manejo endoscópico mínimamente invasivo, seguido de uretroplastia con injerto con porcentajes de 69,9% y 25,5% respectivamente. Solo el 5% prefiere derivar a sus pacientes a un centro especializado. Para la estrechez de la uretra bulbar se prefiere las técnicas mínimamente invasivas, uretroplastia y remisión a un centro especializado en un 44,3%, 41,5% y 14,2% respectivamente. La población más joven y con formación urológica más reciente tiende a hacer más a menudo la uretroplastia con injerto y menos manejo endoscópico, específicamente la uretrotomía interna. En las ciudades intermedias, hay una predilección por el tratamiento endoscópico, especialmente uretrotomía interna.

Conclusiones El enfoque de tratamiento mínimamente invasivo de la estrechez uretral es el más frecuentemente elegido a pesar de sus pobres tasas de éxito a largo plazo. Es de destacar que las nuevas generaciones de urólogos muestran más interés y dominio de las técnicas abiertas, tratamiento estándar hoy en día y con bajas tasas de recaídas y reoperación a largo plazo.

Excision and Primary Anastomosis Reconstruction for Traumatic Strictures of the Pendulous Urethra

OBJECTIVES

To present a multi-institutional experience with functional and patient-reported outcomes among men undergoing excision and primary anastomosis (EPA) urethroplasty for pendulous urethral strictures.

METHODS

We describe the technique and present our experience with EPA for focal penile strictures. Patients undergoing urethroplasty (2004-2017) at 2 tertiary referral centers were reviewed, of whom 14 (0.7%) underwent EPA of radiographically confirmed pendulous urethral strictures. Validated questionnaires were utilized to evaluate overall improvement (Patient Global Impression of Improvement), urinary bother (International Prostate Symptom Score), and sexual function (International Index of Erectile Function-5). Treatment success was defined as urethral patency without need for subsequent reconstruction.

RESULTS

Among 14 men undergoing penile EPA, 13/14 (93%) had durable treatment success over a median follow-up of 43 months. No patient reported penile curvature postoperatively. Stricture etiology in most cases was posttraumatic (12/14), of which 4 had a history of urethral disruption secondary to penile fracture and 8 iatrogenic trauma. Median age was 51 years (IQR 30-60) and stricture length 1.0 cm (IQR 1.0-1.4). Erectile function was normal in 8/14 patients preoperatively, and postoperative median International Index of Erectile Function was 21. Most men reported significant global improvement in condition (median Patient Global Impression of Improvement 2, IQR 1-3) and most had only mild urinary bother (median International Prostate Symptom Score 4, quality of life 1). The single treatment failure had a history of hypospadias with multiple prior urethral procedures.

CONCLUSION

For men with short strictures of the pendulous urethra, EPA has a high success rate, without adverse sequelae such as erectile function or penile curvature.

[Results of anastomotic urethroplasty for male urethral stricture disease]

OBJECTIVE

To report our experience with anastomotic uretroplasty (AU) due to male urethral stricture disease (USD) and to identify factors affecting the results.

PATIENTS AND METHODS

We conducted a retrospective study over a period of 4 years and 6 months (July 2012 to December 2016). Any subsequent use of endoscopic urethrotomy or new urethroplasty was considered a failure.

RESULTS

Forty-eight cases were included. The mean age of patients was 53.5±17.3 years (23-87 years). Urinary retention was the reason for consultation in 42 cases (87.5%). The most common localization of USD was the bulbar urethra (n=45). The mean length of USD was 1.23±0.62cm (0.5-3cm) with a median length of 1cm. The etiology was post-infectious in 56.3% of cases. More than half (58.3%) of patients had already undergone at least one urethral manipulation. After an average follow-up of 21.1±12.6 months (1 to 52 months), the overall success rate was 77.1%. In univariate analysis, length, cause and location of the stricture, age of patient, the presenting symptoms of the stricture, previous urethral manipulation and surgeon experience did not significantly impact on the success rate of anastomotic urethroplasty at one and two years follow-up.

CONCLUSION

The AU had provided good results in our practice. The infectious origin of the stricture and previous urethral manipulation did not significantly impact the result of this surgical technique.

LEVEL OF EVIDENCE

4.

Penile Allotransplantation for Complex Genitourinary Reconstruction

PURPOSE

Reconstruction of complex functional structures is increasingly being performed with vascularized composite allotransplantation. Penile transplantation is a novel vascularized composite allotransplantation treatment option for severe penile tissue loss and disfigurement. Three allogeneic human penile transplantations have been reported. We review these cases as well as penile transplant indications, preclinical models and immunosuppression therapy.

MATERIALS AND METHODS

We performed a comprehensive literature review for the years 1970 to 2016 via MEDLINE®, PubMed® and Google with the key words "penis transplantation," "penile rejection," "penile replantation," "penile tissue loss" and "penis vascularized composite allotransplantation." Relevant articles, including original research, reviews and nonscientific press reports, were selected based on contents, and a review of this literature was generated.

RESULTS

Three human allogeneic penile transplantations have been performed to date, of which 1 was removed 14 days after transplantation. The second recipient reports natural spontaneous erections and impregnating his partner. All 3 patients were able to void spontaneously through the graft's urethra. The complexity of the transplant is determined by how proximally the penile shaft anastomosis is performed and additional pelvic tissue may be transplanted en bloc if needed.

CONCLUSIONS

Penile transplantation is a technically demanding procedure with significant ethical and psychosocial implications that can provide tissue and functional replacement, including urinary diversion and natural erections. It is unclear how rejection and immunosuppression may affect graft function. Better models and more preclinical research are needed to better understand and optimize penile transplantation.

The effect of urethral transection on erectile function after anterior urethroplasty

PURPOSE

To prospectively assess the effect of urethral transection on erectile function after anterior urethroplasty.

METHODS

From February 2012 to December 2014, 104 patients were enrolled in a prospective study assessing erectile function (EF) after anterior urethroplasty. Participants completed the International Index of Erectile Function (IIEF) questionnaire preoperatively and 6 months postoperatively. Outcome measures were the incidence of erectile dysfunction (ED) defined by ≥5-point change in EF and mean change in the EF domain. Factors examined were urethral transection, stricture location, patient age and other demographics. Fisher's exact test, Student's t test and linear regression were used to evaluate associations when appropriate.

RESULTS

Seventeen patients were excluded because of poor EF, leaving 87 patients for analysis. Twenty-two patients (25.3 %) had urethral transection during urethroplasty, while 65 underwent non-transecting techniques (74.7 %). For the entire cohort, IIEF scores remain unchanged (20.16 versus 20.14; p = 0.98). Eighteen patients (20.7 %) developed ED, while 15 (17.2 %) experienced an improvement in EF. Urethral transection was not associated with ED (p = 0.22) or mean change in EF (-0.8 versus +0.2; p = 0.71). Stricture location was not associated with ED, but patient age ≥50 was associated with a decrease in mean postoperative EF (-2.84 versus +1.85; p = 0.04). On linear regression analysis patient age remained independently associated with adverse change in EF (p = 0.05).

CONCLUSIONS

Urethroplasty can result in a decline in erectile function in some patients but overall is associated with minimal change in erectile function. Urethral transection is not associated with adverse change in erectile dysfunction after urethroplasty however, advanced patient age is.

Early removal of urinary catheter after excision and primary anastomosis in anterior urethral stricture

OBJECTIVE

To investigate the feasibility of removing the urinary catheter 7 days after excision and primary anastomosis (EPA) performed with the indication of anterior urethral stricture disease.

MATERIAL AND METHODS

Retrospective review of medical records of the patients who had undergone EPA between January 2005 and December 2010 was performed. These patients were divided into 2 groups: Group 1 (urethral catheter removed on or before 7. postoperative day) and Group 2 (urethral catheter removed on 8. postoperative day or later). We compared 2 groups as for the frequency of extravasation as detected on retrograde pericatheter urethrogram (PUG) and recurrence rate till the last follow-up.

RESULTS

PUG was performed on an average day 7 and 14 in Groups 1 (n=102) and 2 (n=134), respectively followed by removal of the catheter. Extravasation on the first PUG was detected in 6.8% of the patients in Group 1, and in 4.5% of the cases in Group 2 had extravasation on the first PUG. Urethral catheter was left in situ in these patients and a repeat PUG after one week was performed which was normal in all cases. The incidence of extravasation and recurrence rate did not differ significantly whether catheter was removed on day 7 or 14 (6.8% vs. 4.5% and 4.9% vs. 5.2% respectively) (p>0.5).

CONCLUSION

We conclude that removal of the catheter on postoperative day 7 after EPA does not increase the rate of extravasation and recurrence during long-term follow-up. Urethral catheter restricts physical activity in the postoperative period which is bothersome to the patient. Hence early removal of a catheter should be offered to men after EPA.

Use of holmium laser for urethral strictures in pediatrics: A prospective study

INTRODUCTION

The management of urethral strictures is very challenging and requires the wide expertise of different treatment modalities ranging from endoscopic procedures to open surgical interventions.

OBJECTIVE

To assess the effectiveness and complications of retrograde endoscopic holmium: yttrium-aluminum-garnet laser (Ho: YAG) urethrotomy (HLU) for the treatment of pediatric urethral strictures.

PATIENTS AND METHODS

From January 2010 to January 2013, 29 male pediatric patients with a mean age of 5.9 years and primary urethral strictures 0.5-2 cm long were treated using HLU. The stricture length was <1 cm in 16 (55%) patients and >1 cm in 13 (45%). Fifteen (51.7%) patients had an anterior urethral stricture, while 14 (48.3%) had a posterior urethral stricture. No positive history was found in 14 (48.3%) patients for the stricture disease, while six (20.7%) had straddle trauma and nine (31%) had an iatrogenic stricture. All of the patients were pre-operatively investigated and at 3 and 6 months postoperation by uroflowmetry and voiding cystourethrography (VCUG). If there were suspicious voiding symptoms, selective uroflowmetry and VCUG were performed at 12 months postoperation.

RESULTS

The mean operation time was 31.7 min (20-45 min). Twenty-three (79.3%) and 18 (62.1%) patients showed normal urethra on VCUG with improvement of symptoms at 3 and 6 months, respectively. Thus, recurrence was 37.9% after 6 months of follow-up. The mean pre-operative peak urinary flow rate (Qmax) was 6.47 ml/s. The mean postoperative Qmax at 3 and 6 months was 17.17 ml/s and 15.35 ml/s, respectively. The success rate and flowmetry results did not show any statistical significance in relation to site, length and cause of the strictures. The other 11 patients who failed to improve underwent repeated HLU sessions: 4/11 (36.3%) achieved successful outcomes. Among the seven patients with failed HLU for the second time, a third session was conducted. However, only one patient (14.2%) was cured, while open repair was needed for the remaining six.

DISCUSSION

One study has previously been published on the management of pediatric urethral strictures using HLU. The present results are similar to short-term studies after a single session of visual internal urethrotomy using cold knife (VIU). In the present study, the length, location and cause of strictures did not significantly affect the results. However, the outcomes with strictures <1 cm were better than strictures >1 cm, although patients with strictures >2 cm were excluded. In the present study, the success rates among patients with second and third sessions of HLU were 36.3% and 14.2%, respectively. This was similar to other studies, which reported low success rate with the second session of VIU. The present study was limited by the relatively short period of follow-up and the small number of patients. However, it was the first prospective study evaluating HLU for pediatric strictures. The use of flowmetry and VCUG for evaluation of all patients added to the strength of the study.

CONCLUSION

HLU can be safely used with good success rates for the treatment of primary urethral strictures (<2 cm) in children. Repeat HLU (more than twice) adds little to success.

Bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes versus cold-knife transurethral incision for the treatment of posterior urethral stricture: a prospective, randomized study

OBJECTIVE

Evaluate the efficiency and safety of bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes for the treatment of posterior urethral stricture. Compare the outcomes following bipolar plasma vaporization with conventional cold-knife urethrotomy.

METHODS

A randomized trial was performed to compare patient outcomes from the bipolar and cold-knife groups. All patients were assessed at 6 and 12 months postoperatively via urethrography and uroflowmetry. At the end of the first postoperative year, ureteroscopy was performed to evaluate the efficacy of the procedure. The mean follow-up time was 13.9 months (range: 12 to 21 months). If re-stenosis was not identified by both urethrography and ureteroscopy, the procedure was considered "successful".

RESULTS

Fifty-three male patients with posterior urethral strictures were selected and randomly divided into two groups: bipolar group (n=27) or cold-knife group (n=26). Patients in the bipolar group experienced a shorter operative time compared to the cold-knife group (23.45±7.64 hours vs 33.45±5.45 hours, respectively). The 12-month postoperative Qmax was faster in the bipolar group than in the cold-knife group (15.54±2.78 ml/sec vs 18.25±2.12 ml/sec, respectively). In the bipolar group, the recurrence-free rate was 81.5% at a mean follow-up time of 13.9 months. In the cold-knife group, the recurrence-free rate was 53.8%.

CONCLUSIONS

The application of bipolar plasma-cutting and plasma-loop electrodes for the management of urethral stricture disease is a safe and reliable method that minimizes the morbidity of urethral stricture resection. The advantages include a lower recurrence rate and shorter operative time compared to the cold-knife technique.

Practice Patterns in the Treatment of Urethral Stricture Among American Urologists: A Paradigm Change?

OBJECTIVE

To examine surgical case volume characteristics among certifying urologists associated with treatment of urethral stricture to compare practice patterns of recent graduates to recertifying attending urologists and trends over time.

MATERIALS AND METHODS

Six-month case log data of certifying and recertifying urologists (2003-2013) were obtained from the American Board of Urology. Cases specifying a CPT code for urethral dilation, direct vision internal urethrotomy (DVIU), urethroplasty, and graft harvest in males ≥18 years were analyzed for surgeon-specific variables.

RESULTS

Among 6320 urologists logging at least one reconstructive urology procedure, 95,747 (86.2%) urethral dilations, 10,986 (10.0%) DVIU, and 4349 (3.9%) urethroplasties were identified, with 99 (0.9%) using graft and 405 (9.3%) staged procedures. Overall ratio of urethral dilation/DVIU to urethroplasty was 24.5:1. More recent log year and new certification correlated with a decrease in ratio of dilation/DVIU to urethroplasty, but stable use of graft. The ratio of dilation/DVIU to urethroplasty for new certification was much lower (7.9:1), compared to first (24.4:1), second (63.3:1), and third recertification cycles (99.5:1), wherein urethroplasty was increasingly rare. Newly certifying urologists performed urethroplasty 4.5 times more often than those recertifying. Academically affiliated urologists were 8 times more likely to perform urethroplasty.

CONCLUSION

Most urethral strictures are treated with dilation/DVIU, but a changing paradigm favoring urethroplasty is evident. Most urethroplasties are performed by a small number of urologists with high volume, academic affiliation, recent residency graduation, and residence in a state with a reconstructive urology fellowship.

International multi-institutional experience with the vessel-sparing technique to reconstruct the proximal bulbar urethra: mid-term results

OBJECTIVE

To present mid-term outcomes from an international, multi-institutional cohort of patients undergoing vessel-sparing excision and primary anastomosis urethroplasty for the reconstruction of the anterior urethra.

MATERIALS AND METHODS

From June 2003 to December 2011, 68 patients underwent vessel-sparing anterior urethral reconstruction at five different international institutions using the vessel-sparing technique described by Jordan et al. (J Urol 177(5):1799-1802, 2007).

RESULTS

Patients' age range was from 3 to 82 years (mean 51.2). Stricture length ranged from 1 to 3 cm (mean 1.78). After a mean follow-up of 17.6 months, 95.6 % of patients had a widely patent urethral lumen. Three patients failed the procedure, requiring either direct vision internal urethrotomy or urethral dilation, after which all were free of symptoms and did not require further instrumentation. Complications were minimal and as expected following open urethroplasty.

CONCLUSION

Preservation of blood supply is a noble pursuit in surgery; however, it can be technically difficult and often requires more time and effort. This vessel-sparing technique for anterior urethral reconstruction is reproducible and appears to be reliable in this international cohort. Larger studies and longer follow-up are needed to support these encouraging results.

Outcome of urethral strictures treated by endoscopic urethrotomy and urethroplasty

INTRODUCTION

We analyze the outcomes of patients with urethral stricture who underwent surgical treatment within the past 5 years.

METHODS

This is a retrospective study of male patients who underwent surgery for urethral stricture at our service from January 2008 to June 2012. We analyzed the comorbidities, type, length and location of the stricture and the surgical treatment outcome after endoscopic urethrotomy, urethroplasty or both.

RESULTS

In total, 45 patients with a mean age of 53.7 ± 16.7 years underwent surgical treatment for urethral stricture. Six months after surgery, 46.7% of the patients had a maximum urinary flow greater than 15 mL/s, whereas 87.3% of the patients exhibited no stricture by urethrography after the treatment. The success rate in the patients undergoing urethrotomy was 47.8% versus 86.4% in those undergoing urethroplasty (p = 0.01). Twenty percent of the patients in whom the initial urethrotomy had failed subsequently underwent urethroplasty, thereby increasing the treatment success.

CONCLUSION

In most cases, the treatment of choice for urethral stricture should be urethroplasty. Previous treatment with urethrotomy does not appear to produce adverse effects that affect the outcome of a urethroplasty if urethrotomy failed, so urethrotomy may be indicated in patients with short strictures or in patients at high surgical risk.

Low risk of sexual dysfunction after transection and nontransection urethroplasty for bulbar urethral stricture

PURPOSE

Open urethroplasty is the preferred treatment for recurrent bulbar urethral stricture. However, there are still some controversies regarding the optimal technique and the consequences of transecting the urethra in terms of sexual dysfunction, such as erectile dysfunction, penile shortening, impaired glans filling, decreased glans sensibility and ejaculatory function. We performed a retrospective analysis with long-term followup of anastomotic and substitution onlay urethroplasty in bulbar strictures with an emphasis on postoperative sexual function.

MATERIALS AND METHODS

A total of 169 patients with bulbar stricture were treated with urethroplasty via the onlay technique (75) or resection followed by end-to-end anastomosis (94) during 1999 to 2009. Mean followup in the transection and onlay groups was 41 and 69 months, respectively (range 12 to 132). All patients were asked verbally about sexual function during followup. Failure was defined as the need for new surgical intervention.

RESULTS

Erectile dysfunction developed in 1 patient (1%) per group. In the transection group 5 patients (5%), including 4 with longer and more distal strictures, had penile shortening/downward angulation. However, this did not interfere with sexual ability during intercourse. No patient reported impaired glans or ejaculatory function. The success rate in the transection and onlay groups was 91% and 71%, respectively.

CONCLUSIONS

Transection with resection and end-to-end anastomosis is a good method for bulbar stricture with a low rate of sexual dysfunction and a high success rate postoperatively. To avoid penile angulation/shortening, it might be wise to use the onlay technique for longer and distal strictures.

Penile reconstruction

A variety of surgical options exists for penile reconstruction. The key to success of therapy is holistic management of the patient, with attention to the psychological aspects of treatment. In this article, we review reconstructive modalities for various types of penile defects inclusive of partial and total defects as well as the buried penis, and also describe recent basic science advances, which may promise new options for penile reconstruction.

About Surgical Correction of Urethral Stenosis: Urethroplasty

Objective

The aim of our study has been to evaluate our results in the treatment of urethral stenosis through several surgical approaches of urethroplasty: the one-stage procedure by direct end-to-end anastomosis, the free dorsal onlay graft urethroplasty using buccal mucosa, and the two-stage urethroplasty.

Methods

Between February 2009 and January 2012, 53 patients were enrolled and analyzed for different types of urethral reconstruction.

Results

The procedures included direct end-to-end anastomosis in 26 patients (49%), 18 (34%) underwent a two-stage urethroplasty (Johansen's), in 9 a free dorsal onlay buccal mucosa urethroplasty was performed. At a mean follow-up of 17 months, we had an overall success rate of 95%. When stratified on the basis of the procedure performed, in the direct end-to-end anastomosis 98% of patients had no evidence of recurrent stricture, 96% of success rate was reached in the onlay buccal mucosa urethroplasty, and 91% in the two-stage procedure.

Conclusions

In patients with urethral strictures, urethroplasty has to be preferred with respect to urethrotomy, which is the cause of a high percentage of recurrence, and holds the risk of compromising the success of further surgical procedures of urethroplasty. Differently, several techniques of urethroplasty offer a high percentage of success rate until 95%, as showed by our results.

Single-stage reconstruction of complex anterior urethral strictures using overlapping dorsal and ventral buccal mucosal grafts

Study Type - Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? This technique has been reported to have an excellent success rate in the bulbar urethra, although no data exists for its use in the penile urethra. This is the first study to report successful use of the technique in the reconstruction of penile urethral strictures.

OBJECTIVE

• To review our initial experience with single-stage overlapping dorsal and ventral buccal mucosa graft (BMG) urethroplasty for the reconstruction of complex anterior urethral strictures.

PATIENTS AND METHODS

• Among 696 urethroplasties performed at two tertiary urethroplasty centres from October 2007 to September 2010, single-stage urethral reconstruction using urethral plate incision and/or excision and overlapping dorsal and ventral BMGs was used in 36 men (5%) with complex urethral strictures (mean length 4.5 cm). • Demographic and perioperative data was tabulated and outcomes were analysed.

RESULTS

• Stricture location was bulbar (61%), penile (19%), or both bulbar and penile (20%). • Dorsal grafts, applied only within the most severely strictured segment, measured a mean 42% of the opposing ventral graft length. • At a mean follow-up of 15.7 months, 32 of the 36 cases were successful (89%). • Repeat urethroplasty was performed in all four recurrences, three of which were successful at a mean follow-up of 16 months.

CONCLUSION

• Single-stage reconstruction of focally obliterative long urethral strictures using overlapping dorsal and ventral BMGs is safe and effective.

[Rational and selective management of patients with anterior urethral stricture disease]

INTRODUCTION

the management of anterior urethral stricture is controversial. A review article was written, which updates the current situation of the surgical treatment of anterior urethral stricture.

MATERIALS AND METHODS

the experience of the Hospital del Trabajador in Santiago de Chile regarding its different surgical approaches, as well as scientific literature on the topic, were reviewed.

RESULTS

traditionally, anterior urethral stricture has been treated using minimally invasive techniques (dilatation and internal urethrotomy), which are unable to cure more than 30-35% of patients. On the other hand, urethral reconstruction surgery (urethroplasty) is more complex and requires training, however it can cure a wide majority of patients in a single surgical procedure. Due to a lack of experience and training in reconstructive surgery, non-invasive methods are overused and abused, to the detriment of the patients' quality of life. There is substantial evidence that internal urethrotomy is an excellent method for treating stricture of up to 1cm in length, however its efficacy decreases drastically above 1.5cm. Notwithstanding, urethroplasty is directly indicated for larger strictures, especially if prior urethrotomy failed.

CONCLUSION

this procedure must be managed selectively, applying the appropriate treatment aimed at curing and not only palliating the disease. Urologists must be better trained in urethroplasty and/or centres of excellence must be established to be able to offer the best treatment in each case.

[Interventional and surgical treatment of urethral strictures. End-to-end anastomosis]

Excision with primary anastomosis is an excellent reconstructive option for short bulbar and membranous urethral strictures. With adequate patient selection including history, physical examination, and radiographic staging success rates between 90 and 95% in appropriately selected patients can be achieved. Success with this reliable method is based on adequate excision of the complete urethral stricture and sufficient mobilization of the urethra with tension-free anastomosis. Complications affecting ejaculation or penile sensitivity are rare and might be avoided by appropriate surgical techniques. Resection of the stricture and urethral end-to-end anastomosis represents the "gold-standard" in the treatment of bulbar and membraneous strictures up to a length of 3 cm.

A simplified protocol for evaluating and monitoring urethral stricture patients minimizes cost without compromising patient outcome

Uroflowmetry, urethrocystoscopy and urethrography are either not readily available or the cost is prohibitive for many patients in low-resource countries. This paper examines the use of clinical history in post-urethroplasty follow-up. We retrospectively reviewed the outcome of 54 post-urethroplasty patients. Preoperative diagnostic work-up included simple blood tests and a retrograde urethrography, and postoperatively we did not perform any immediate diagnostic work-up. Follow-up of these patients was done through mobile phone calls and personal contacts. Eighty-nine per cent of our patients reported acceptable voiding over a mean follow-up period of 48.4 months - 79.6% were followed using mobile phone contact. In the majority of the urethral strictures cases, diagnostic work up can be kept to a minimum, thereby reducing cost. Follow-up can be done via phone calls and personal contact in many African countries where compliance is frequently less than encouraging. The spread of mobile phone networks across the continent has been remarkable.

Synchronous urethral stricture reconstruction via 1-stage ascending approach: rationale and results

PURPOSE

We present our experience with the reconstruction of synchronous urethral strictures.

MATERIALS AND METHODS

Of 482 anterior urethroplasties performed by a single surgeon between 1997 and 2008 we identified and reviewed 30 patients who underwent reconstruction for multiple separate strictures. An ascending approach from distal to proximal was used and all repairs were completed at 1 stage. A total of 13 combinations of techniques were used to complete the repairs. A 2-phase technique was used in which the patient remained supine during buccal mucosa harvest and repair of strictures distal to the penoscrotal junction, and was then repositioned into the high lithotomy position as needed for stricture repair in the bulbar urethra. In each case normal intervening urethra was preserved intact. The number, length and location of strictures, operative time and patient outcomes were evaluated.

RESULTS

No position related complications occurred during or after surgery despite a mean operative time of 4.5 hours (range 2.5 to 6.4). No infectious wound complications were reported despite repositioning the legs to the high lithotomy position. Three patients (10%) were known to have required treatment for recurrent stricture after surgery.

CONCLUSIONS

One-stage reconstruction for synchronous urethral strictures may be safely and effectively performed using a systematic, ascending reconstructive approach with creative application of tissue transfer techniques. Decreasing patient time in the high lithotomy position appears to prevent related lower extremity complications.

Can bipolar vaporization be considered an alternative energy source in the endoscopic treatment of urethral strictures and bladder neck contracture?

OBJECTIVE

We evaluated the outcome of bipolar energy by using PlasmaKinetic(TM) cystoscope instruments in the treatment of urethral stricture and bladder neck contracture.

MATERIALS AND METHODS

Twenty-two male patients with urethral stricture and five with bladder neck contracture were treated by endoscopic bipolar vaporization. The most common etiology for stricture formation was iatrogenic (85.2%) and the mean stricture length was 12.2 mm. All patients were evaluated with urethrography and uroflowmetry one month and 3 months after surgery. Urethroscopy was routinely performed at the end of the first year. Preoperative mean maximum flow rate (Q max) was 4.9 mL/s for urethral stricture and mean Q max was 3.4 mL/s for bladder neck contracture. The results were considered as "successful" in patients where re-stenosis was not identified with both urethrography and urethroscopy. Minimum follow-up was 13.8 months (range 12 to 20).

RESULTS

Tissue removal was rapid, bleeding was negligible and excellent visualization was maintained throughout the vaporization of the fibrotic tissue. Postoperative mean Q max was 14.9 mL/s and the success rate was 77.3% for urethral stricture at mean follow-up time of 14.2 months. The success rate was 60% with a mean follow-up time of 12.2 months for bladder neck contracture and the mean Q max was 16.2 mL/s, postoperatively.

CONCLUSIONS

The study suggests that bipolar vaporization is a safe, inexpensive and reliable procedure with good results, minimal surgical morbidity, negligible blood loss, and thus, it could be considered as a new therapeutic option for the endoscopic treatment of urethral stricture and bladder neck contracture.

Buccal mucosa graft urethroplasty for anterior urethral stricture repair: evaluation of the impact of stricture location and lichen sclerosus on surgical outcome

PURPOSE

We report our experience with buccal mucosa grafts for anterior urethral strictures. We compared outcomes in the pendulous and bulbar urethra as well as the impact of lichen sclerosus on success.

MATERIALS AND METHODS

A total of 53 men underwent buccal mucosa graft urethroplasty from 1997 to 2004 for strictures of all etiologies, including lichen sclerosis in 13. Of the patients 46 underwent 1-stage repair and 7 with full-thickness circumferential disease underwent multistage repair. For 1-stage repair strictures were limited to the bulb in 33 cases and they involved the pendulous urethra in 13. A dorsal onlay was used in 24 cases and a ventral onlay was used in 22. For multistage urethroplasty 2 strictures were in the bulbar urethra and 5 were in the pendulous urethra. Success was defined as no postoperative procedures or complications.

RESULTS

The success rate of all urethroplasties was 81% (43 of 53 cases) at a mean followup of 52 months. For bulbar vs pendulous urethroplasty the success rate was 86% (30 of 35 cases) vs 72% (13 of 18, p = 0.23). For 1-stage urethroplasty by graft location success was achieved in 20 of 24 cases (83%) for dorsal onlay vs 17 of 22 (77%) for ventral onlay (p = 0.61), in 18 of 21 (86%) for bulbar-dorsal onlay, in 10 of 12 (83%) for bulbar-ventral onlay, in 2 of 3 (66%) for pendulous-dorsal onlay and in 7 of 10 (70%) for pendulous-ventral onlay. For multistage urethroplasty success was achieved in 2 of 2 cases (100%) for bulbar repair vs 4 of 5 (80%) for pendulous repair. In the 13 patients with lichen sclerosus success was achieved in 4 of 8 (50%) with 1-stage repair vs 4 of 5 (80%) with multistage repair (p = 0.28). Complications developed in 10 of 53 cases (19%), including fistula in 1, urinary tract infection in 1 and stricture in 8 that required treatment, including dilation in 3, internal urethrotomy in 4 and perineal urethrostomy in 1. Five of these 8 recurrent strictures (63%) developed in patients with lichen sclerosus, including 4 in urethras in which 1-stage repair was done for lichen sclerosus. There were no donor site complications, postoperative erectile dysfunction or chordee.

CONCLUSIONS

A buccal mucosa graft placed dorsally or ventrally remains an excellent graft material in the bulbar and pendulous urethra. When lichen sclerosus is present, careful consideration should be given to complete excision of the diseased urethra with multistage repair vs accepting a higher rate of stricture recurrence with 1-stage repair.

Long-term followup for excision and primary anastomosis for anterior urethral strictures

PURPOSE

We report our experience and long-term followup of patients undergoing excision and primary anastomotic reconstruction for anterior urethral strictures.

MATERIALS AND METHODS

From July 1986 to May 2006 the charts of 260 patients who underwent excision with primary anastomosis at our center for bulbar urethral stricture were reviewed. Patient age ranged from 14 to 78 years (mean 38.4), stricture length ranged 0.5 to 4.5 cm (mean 1.9). Patients who had surgery within the last 5 years were contacted by telephone if their 6-month postoperative cystoscopic evaluation was patent and they had not visited the clinic afterward.

RESULTS

After a mean followup of 50.2 months 257 patients (98.8%) were symptom-free and required no further procedures. Recurrent stricture occurred early in 2 patients and late in 1 patient. Two patients opted for intermittent dilations, and a single direct visual internal urethrotomy was performed in 1 patient 4 years postoperatively. One of the patients who elected dilation subsequently elected urethral reconstruction, which was done successfully. Complications encountered were position related neuropraxia in 9 (3.4%), early urinary tract infection in 13 (5%), chest related in 5 (1.9%), scrotalgia in 4 (1.5%) and wound related in 4 (1.5%). All resolved within the early postoperative period. Erectile dysfunction was encountered in 6 (2.3%) patients, of whom 4 had a history of significant straddle trauma, 4 responded well to oral pharmacotherapy and 1 elected to not have the erectile dysfunction treated.

CONCLUSIONS

Excision with primary anastomosis for anterior urethral stricture has a high success rate of 98.8% with durable long-term results in most patients. Complications are few, of short duration and self-limited. Where applicable, we believe that the procedure clearly is the choice for short anterior urethral strictures.

Adult Anterior Urethral Strictures: A National Practice Patterns Survey of Board Certified Urologists in the United States

PURPOSE

We determined the methods and patterns of the evaluation of and treatment for adult anterior urethral stricture disease by practicing urologists in the United States.

MATERIALS AND METHODS

A nationwide survey of practicing members of the American Urological Association was performed by a mailed questionnaire. A total of 1,262 urologists were randomly selected from all 50 states, of whom 431 (34%) completed the questionnaire.

RESULTS

Most urologists (63%) treat 6 to 20 urethral strictures yearly. The most common procedures used by those surveyed for urethral strictures were dilation (92.8%), optical internal urethrotomy (85.6%) and endourethral stent (23.4%). Minimally invasive procedures are used more frequently that any open urethroplasty technique. Furthermore, most urologists (57.8%) do not perform urethroplasty surgery. When used, the most common urethroplasty surgeries performed were end-to-end anastomotic urethroplasty, perineal urethrostomy and ventral skin graft urethroplasty. Few urologists (4.2%) performed buccal mucosa grafts. For a long bulbar urethral stricture or short bulbar urethral stricture refractory to internal urethrotomy 20% to 29% of respondents would refer to another urologist, while 31% to 33% would continue to manage the stricture by minimally invasive means despite predictable failure. Of the urologists 74% believed that the literature supports a reconstructive surgical ladder, in which urethroplasty is only performed after repeat failure of endoscopic methods.

CONCLUSIONS

Most urologists in the United States have little experience with urethroplasty surgery. Most urologists erroneously believe that the literature supports a reconstructive surgical ladder for urethral stricture management. Unfamiliarity with the literature and inexperience with urethroplasty surgery have made the use of endoscopic methods inappropriately common.

Proximal bulbar urethroplasty via extended anastomotic approach--what are the limits?

PURPOSE

We report our initial experience with men who underwent EAU for strictures greater than 2.5 cm involving the proximal bulbar urethra.

MATERIALS AND METHODS

Of the more than 250 men who underwent urethral reconstruction at our institution during 1997 to 2005 a select consecutive group of 22 in whom proximal bulbar urethral strictures were treated with primary bulbomembranous anastomosis were evaluated. Outcomes in men with strictures greater than 2.5 cm long (EAU) were compared to those in men with shorter strictures in the same proximal bulbar location. Cases of post-traumatic urethral disruption related to pelvic fractures were omitted. American Urological Association symptom index scores and erectile function questionnaires were completed more than 6 months postoperatively. Results of a prior study using the same erectile function questionnaire after various types of urethroplasty and circumcision were then compared to those of our series.

RESULTS

Patients with EAU had an average stricture length of 3.78 cm (range 2.6 to 5.0) and 10 of 11 procedures (91%) were successful. Anastomotic urethroplasty performed for similar proximal bulbar strictures less than 2.5 cm (mean 1.5, range 1.0 to 2.3) was successful in 10 of 11 cases (91%). Mean followup was 22.1 months and all followups were more than 1 year. Men treated with EAU had no increased rate of stricture recurrence or erectile complaints compared to men in whom shorter proximal bulbar strictures were repaired using an identical surgical technique. Similarly no increased rate of erectile problems was identified compared to other types of urethroplasty and circumcision using an identical questionnaire.

CONCLUSIONS

Urethral reconstructability is proportional to the length and elasticity of the distal urethral segment. Defects up to 5 cm may be successfully excised and primarily reconstructed in select young men with proximal bulbar strictures.

Early catheter removal after anterior anastomotic (3 days) and ventral buccal mucosal onlay (7 days) urethroplasty

INTRODUCTION

Physicians who perform urethroplasty have varying opinions about when the urinary catheter should be removed post-operatively, but research on this subject has not yet appeared in the literature. We performed voiding cystourethrogram (VCUG) on our anterior urethroplasty patients on days 3 (anastomotic) and 7 (buccal) in an effort to determine the earliest day for removal of the urethral catheter.

MATERIALS AND METHODS

Retrospective chart review of 29 urethroplasty patients from October 2002-August 2004 was performed at two reconstructive urology centers. 17 patients had early catheter removal (12 anastomotic and 5 ventral buccal onlay urethroplasty) and were compared to 12 who had late removal (7 anastomotic and 5 buccal).

RESULTS

Of those with early catheter removal, 2/12 (17%) of anastomotic urethroplasty patients had extravasation, which resolved by the following week and 0/5 (0%) of the buccal mucosal urethroplasty patients had extravasation. Patients with late catheter removal underwent VCUG 6-14 days (mean 8 days) after anastomotic urethroplasty and 9-14 days (mean 12 days) after buccal mucosal urethroplasty. 0% of the anastomotic urethroplasty had leakage after the late VCUG and 1/5 (20%) of the buccal patients had extravasation after the VCUG. Recurrences were low in all patient groups.

CONCLUSION

Catheter removal after anastomotic and buccal mucosal urethroplasty can be safely attempted on the 3rd and 7th post-operative days respectively, with a low rate of extravasation on VCUG. Eliminating the catheter as soon as possible should improve patient comfort without harming results and decrease the overall negative impact of surgery on the patient.

[Long-term results of end-to-end urethroplasty]

OBJECTIVE

We evaluated long term results of end-to-end urethroplasty.

MATERIAL AND METHODS

We reviewed 40 patients with bulbar urethral stricture of diverse origin: iatrogenic 40%, traumatic 15%, infectious 2% and unknown 40%. In 17 cases internal urethrotomy was made previously. The radiological study with retrograde and voiding cystogram revealed a bulbar location in all cases and a length inferior to 1 cm in 13 cases, between 1-2 cm in 26 cases and 2-3 cm in 1 case. The maximum flow rate varied between 3-13 ml/s. The absence of bacteriuria was valued by means of preoperating culture. The average time of pursuit was 45 months (12-142 months). The stricture was considered resolute when not appear compatible radiological or functional finds of failure.

RESULTS

In 37 cases (92%) the results were satisfactory, without secondary surgical procedure. After surgery maximum flow-rate varied between 18-45 ml/s. In two patients with failure, internal urethrotomy was decisive. In this case the stricture origin was traumatic. The third patient with failure was finally chosen to make new end-to-end urethroplasty, with good later result.

CONCLUSIONS

End-to-end urethroplasty is a highly decisive technique for bulbar urethral stricture. The preoperating diagnosis is based on the radiological study (retrograde and voiding cystogram). The postoperating control must be based on clinic and uroflow study. Traumatic stricture repair showed worse results. In cases of failure, internal urethrotomy allows to complement successful results of end-to-end urethroplasty.

Primary urethral reconstruction: the cost minimized approach to the bulbous urethral stricture

PURPOSE

Treatment for urethral stricture disease often requires a choice between readily available direct vision internal urethrotomy (DVIU) and highly efficacious but more technically complex open urethral reconstruction. Using the short segment bulbous urethral stricture as a model, we determined which strategy is less costly.

MATERIALS AND METHODS

The costs of DVIU and open urethral reconstruction with stricture excision and primary anastomosis for a 2 cm bulbous urethral stricture were compared using a cost minimization decision analysis model. Clinical probability estimates for the DVIU treatment arm were the risk of bleeding, urinary tract infection and the risk of stricture recurrence. Estimates for the primary urethral reconstruction strategy were the risk of wound complications, complications of exaggerated lithotomy and the risk of treatment failure. Direct third party payer costs were determined in 2002 United States dollars.

RESULTS

The model predicted that treatment with DVIU was more costly (17,747 dollars per patient) than immediate open urethral reconstruction (16,444 dollars per patient). This yielded an incremental cost savings of $1,304 per patient, favoring urethral reconstruction. Sensitivity analysis revealed that primary treatment with urethroplasty was economically advantageous within the range of clinically relevant events. Treatment with DVIU became more favorable when the long-term risk of stricture recurrence after DVIU was less than 60%.

CONCLUSIONS

Treatment for short segment bulbous urethral strictures with primary reconstruction is less costly than treatment with DVIU. From a fiscal standpoint urethral reconstruction should be considered over DVIU in the majority of clinical circumstances.