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Sonourethrogram to Manage Adolescent Anterior Urethral Stricture
Diagnostic Imaging
Sonourethrogram to Manage Adolescent Anterior Urethral Stricture Edward M. Gong, Claudia Martinez Rios Arellano, Jeanne S. Chow and Richard S. Lee* From the Departments of Urology and Radiology (CMRZ, JSC), Children’s Hospital Boston, Boston, Massachusetts
Purpose: Accurate measurement of anterior urethral stricture length is critical to determine the appropriate surgical approach. Retrograde urethrogram is often used to determine stricture location and length. However, the adult literature shows that retrograde urethrogram may underestimate stricture length. We investigated the role of sonographic urethrogram in the preoperative evaluation of adolescent urethral stricture disease. Materials and Methods: Between June 2008 and February 2009 we retrospectively evaluated 12 pediatric patients with urethral stricture disease using retrograde and sonographic urethrogram. Stricture length was categorized by 2 radiologists as I—less than 1, II—1 to 3 and III— greater than 3 cm. On sonographic urethrogram stricture length was measured as the longest extent of the urethral abnormality. Results: Mean patient age was 16.9 years (range 9.5 to 20.8). Retrograde urethrogram classified 7 cases as category I, 4 as category II and none as category III stricture, and 1 with no evidence of stricture. Sonographic urethrogram revealed strictures greater than 1 cm in all 7 category I cases and 2 of the 4 category II cases had strictures longer than 3 cm. One patient in whom retrograde urethrogram showed a category II stricture was stricture-free on sonographic urethrogram. One patient with a negative retrograde urethrogram had a stricture on sonographic urethrogram. Sonographic urethrogram upgraded stricture length in 10 of the 12 patients and outperformed retrograde urethrogram in 11. Conclusions: Sonographic urethrogram is effective for evaluating adolescent urethral stricture disease. It may provide more accurate measurement of stricture length and improve preoperative planning.
Abbreviations and Acronyms DVIU ⫽ direct visual internal urethrotomy RUG ⫽ retrograde urethrography SUG ⫽ sonographic urethrography Study received institutional review board approval. * Correspondence: Department of Urology, Children’s Hospital Boston, 300 Longwood Ave., Hunnewell 390, Boston, Massachusetts 02115 (telephone: 617-355-7796; e-mail: richard.lee@ childrens.harvard.edu).
Key Words: urethra, urethral stricture, diagnostic imaging, ultrasonography, adolescent ANTERIOR urethral stricture disease presents with varying degrees of severity. Treatment includes minimally invasive endoscopic procedures and open surgical repair. Appropriate treatment for anterior urethral stricture disease depends on accurate measurement of stricture length. Endoscopic urethrotomy is more likely to be successful for strictures less than 1 cm
long.1 Urethroplasty is generally considered the standard for longer strictures.2 However, this depends on accurate imaging and measurement of urethral stricture length. Several studies indicate that in adults SUG may yield more accurate results to determine stricture length.3–5 This has not been well studied in the pediatric population and most practi-
0022-5347/10/1844-1699/0 THE JOURNAL OF UROLOGY® © 2010 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
Vol. 184, 1699-1702, October 2010 Printed in U.S.A. DOI:10.1016/j.juro.2010.03.074
AND
RESEARCH, INC.
www.jurology.com
1699
1700
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
tioners rely on RUG. We compared the efficacy of SUG vs RUG to determine urethral stricture length in an adolescent population.
METHODS We performed an institutional review board approved, retrospective evaluation of patients with identified stricture on RUG using SUG. Between June 2008 and February 2009, 12 patients with presumed urethral stricture disease underwent SUG. Only patients in the adolescent age group were included in analysis (median age 17 years, range 9 to 20). After urethral stricture disease diagnosis by RUG the patients underwent cystoscopy and SUG with a surgical plan to perform DVIU in those with stricture less than 1 cm long or open urethroplasty for longer strictures. SUG was done in the operating suite with the patient under general anesthesia in the dorsal lithotomy position. The attending surgeon, radiologist and ultrasound technician were present for the procedure. Initially the bladder was filled in retrograde fashion with placement of a small bore Foley catheter at the fossa navicularis unless a suprapubic tube was present. After sufficient bladder distention simultaneous retrograde and antegrade urethral distention was achieved by injecting saline via a catheter at the fossa navicularis and a Credé maneuver. We used a 15L8 ultrasound transducer (Siemens, Berkeley, California) at 14.0 MHz to visualize the urethra. The probe was placed on the perineum or site of the presumed stricture during active urethral distention until adequate visualization was achieved. On SUG strictures were identified by altered echogenicity, luminal narrowing and changes in periurethral tissue. Also, during real-time imaging of urethral strictures the attending surgeon could use the degree of urethral distention to determine functional stricture length. Including patient positioning and setup, ultrasound duration was 12 to 25 minutes. Regardless of severity, any degree of urethral abnormality was considered strictured tissue. Stricture length was measured by drawing perpendicular lines through the urethral lumen at the most proximal and most distal aspects of the urethral stricture. The longest length between these lines was measured at the urethral wall as stricture length (see figure). Using strict criteria, any evidence of fibrosis of urethral or periurethral tissue was considered part of the stricture. Depending on stricture length patients were grouped in 1 of 3 categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. These categories were selected in correlation with the change in treatment due to stricture length. Stricture length on SUG was measured with the assistance of 2 radiologists (the performing radiologist and JSC). Strictures on RUG were estimated by 2 radiologists (JSC and CMRA) to be in 1 of 3 identical categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. Strictures were confirmed surgically at cystoscopy or open surgery. The operative attending surgeon made the final decision on stricture management. Statistical analysis was done with SPSS®, version 14.0.
SUG measurement technique (double-headed arrow) (A) and corresponding RUG with similar stricture length (arrowheads) (B). RUG reveals short, tight stricture (arrowheads) (C), which was longer on SUG (arrowhead) (D).
RESULTS All 12 patients underwent RUG plus SUG. Mean ⫾ SD patient age at SUG was 16.9 ⫾ 3.2 years (range 9.5 to 20.8). Nine strictures were idiopathic, 2 were iatrogenic and 1 was traumatic. Before SUG 5 patients received no prior instrumentation while 2, 2, 2 and 1 underwent DVIU, dilation, suprapubic catheterization and transurethral resection for posterior urethral valves, respectively. All patients had a single stricture. The stricture site was bulbar in 8 cases, penile in 1 and penobulbar in 2. The presenting symptom was slow stream in 5 patients, hematuria in 4, dysuria in 4, and urinary retention and incontinence in 1 each. RUG classified 7 cases as category I, 4 as category II and none as category III stricture. One patient in whom urinary retention was treated with a suprapubic catheter had no stricture on RUG (see table). In contrast, on SUG there were no category I, 7 category II and 4 category III strictures with a mean length of 2.58 cm (range 1.0 to 4.4). Ten of the 12 cases (83.3%) were upgraded in category by SUG. In 1 of these patients with negative RUG who was suspected to have stricture disease due to symptoms SUG identified a 2.6 cm bulbar urethral stricture. Another patient thought to have a stricture on RUG was subsequently found to be stricture-free after SUG with cystoscopic confirmation. Only 1 patient remained in the same category. Including the case in which stricture was misdiagnosed by RUG, SUG outperformed RUG in 11 of 12 cases (91.7%) (see table). In 7 of the 12 patients (58.3%) planned surgery was changed based on SUG results. Also, SUG confirmed the decision to perform primary urethroplasty in 3 patients. All 7 patients in whom surgical
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
Patient demographics Plan RUG Category (pt No.)
SUG Category
Before SUG
After SUG
II II II II II III III
DVIU DVIU DVIU DVIU Urethroplasty DVIU DVIU
DVIU DVIU Urethroplasty Urethroplasty Urethroplasty Urethroplasty Urethroplasty
II III III None II
Dilation Urethroplasty Urethroplasty DVIU DVIU
Urethroplasty Urethroplasty Urethroplasty None Urethroplasty
I: 1 2 3 4 5 6 7 II: 8 9 10 11 None (12)
planning was changed were originally scheduled to undergo DVIU or urethral dilation. Six of the 7 patients underwent open urethroplasty and in the remaining patient no procedure was done since no stricture was identified on SUG. The remaining 2 patients in the study underwent DVIU.
DISCUSSION Management of anterior urethral strictures is controversial in the adult and pediatric populations. Longer, denser strictures are likely better treated with more aggressive open surgical techniques. Treating shorter, less dense strictures with an endoscopic technique may be more cost-effective.6 Some groups advocate initial DVIU regardless of preoperative stricture length, reserving urethroplasty for cases in which 1 endoscopic attempt has failed.7 Others argue that any previous urethral manipulation may have a detrimental effect on the outcome of open surgical repair.8 Diamond et al reported that open urethroplasty as the initial surgical approach has a higher overall success rate in the pediatric population.9 In adults Pansadora and Emiliozzi noted a 71% success rate for strictures less than 1 cm vs an 18% success rate for strictures greater than 1 cm when treated with DVIU.1 In a pediatric population Hafez et al reported an 89% success rate for primary perineal anastomotic urethroplasty with a mean urethral stricture length of 2.6 cm.10 Patients with even longer strictures (mean 3.2 cm) may be better treated with oral mucosa graft repair.11 Based on these reports we separated urethral strictures into 3 categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. RUG with voiding cystourethrography is the classic imaging technique in pediatric patients suspected of having urethral stricture disease. While
1701
RUG can detect urethral stricture disease, it does not provide information on the extent of spongiosal fibrosis and may be inaccurate for measurement. Recently in the adult literature SUG proved to be more beneficial to assess these characteristics.3–5 Gupta et al found that stricture length on SUG correlated better than that on RUG with length measured intraoperatively.5 Choudhary et al reported that RUG and SUG were equally sensitive and specific for strictures less than 1 and greater than 4 cm.3 However, for strictures between 1 and 4 cm SUG was more sensitive and more specific. Beyond the benefit of SUG to determine stricture length it also potentially provides additional information on the health of periurethral tissue.12 Our findings confirm the adult findings in an adolescent population. While most strictures measured on RUG were thought to be short (category I), SUG identified no category I strictures. All strictures were category II (7 cases) or III (4). Furthermore, SUG detected a significant stricture in a patient in whom RUG was negative. This misdiagnosis by RUG may have been secondary to poor radiograph exposure. SUG also ruled out stricture disease in a patient with worrisome narrowing on RUG. In this study direct length comparison between RUG and SUG was not possible. Exact RUG stricture length could not be determined. Without knowing precisely the distance from the x-ray source and sensor to the patient, direct measurement of stricture length was not possible. This is similar to the concept that only postero-anterior x-rays should be used to determine heart size since anteroposterior x-rays falsely increase heart size by moving the patient farther from the x-ray plate. Due to the retrospective nature of this study and to the different surgical approaches we did not measure exact intraoperative stricture length. Several surgeons did not include measured stricture length in the operative note and several did not measure intraoperative stricture length. These surgeons cut down directly on the area of palpable stricture and, using visual and tactile cues, extend the excised portion of the urethra proximal and distal until it is felt that no fibrotic tissue remains. Furthermore, since strictured tissue arrives piecemeal to pathologists, it was not possible to use histological analysis to determine stricture length. Another potential limitation of our study is a result of the increased sensitivity of SUG detection and our criteria for measuring stricture length. Peskar and Perovic attempted to account for this discrepancy by measuring 2 lengths on each SUG, including total urethral stricture length and the length of maximally reduced lumen.12 Although this measurement technique measures the maximally affected length, that length does not necessarily in-
1702
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
clude all tissue that requires surgical resection. We believe that direct communication between surgeon and ultrasonographer is important to arrive at a mutual determination of significant stricture. Intraoperative SUG after urethral exposure may further help determine the extent of disease. Although SUG is performed using anesthesia, it has an important role in assessing urethral stricture length in the pediatric population and it may potentially provide the critical information to determine the optimal corrective procedure. We recommend that SUG not be used as a screening tool to detect urethral stricture disease but rather as an adjunct in a treatment algorithm to determine the surgical
approach. Furthermore, the use of SUG should be evaluated for other urethral disorders in the pediatric population, such as post-hypospadiac stricture of the penile urethra.
CONCLUSIONS In this retrospective pilot study SUG in the adolescent population was a useful perioperative adjunct to RUG. SUG provided additional information on stricture length and periurethral fibrosis, and may help guide operative intervention. SUG may be useful in the diagnostic and perioperative evaluation of adolescent urethral stricture.
REFERENCES 1. Pansadora V and Emiliozzi P: Internal urethrotomy in the management of anterior urethral strictures: long-term followup. J Urol 1996; 156: 73. 2. Rourke KF and Jordan GH: Primary urethral reconstruction: the cost minimized approach to the bulbous urethral stricture. J Urol 2005; 173: 1206. 3. Choudhary S, Singh P, Sundar E et al: A comparison of sonourethrography and retrograde urethrography in evaluation of anterior urethral strictures. Clin Radiol 2004; 59: 736. 4. Gupta S, Majumdar B, Tiwari A et al: Sonourethrography in the evaluation of anterior urethral strictures: correlation with radiographic urethrography. J Clin Ultrasound 1993; 21: 231. 5. Gupta N, Dubey D, Mandhani A et al: Urethral stricture assessment: a prospective study evalu-
ating urethral ultrasonography and conventional radiological studies. BJU Int 2006; 98: 149. 6. Wright JL, Wessells H, Nathens AB et al: What is the most cost-effective treatment for 1 to 2-cm bulbar urethral strictures: societal approach using decision analysis. Urology 2006; 67: 889. 7. Hsiao KS, Baez-Trinidad L, Lendvay T et al: Direct vision internal urethrotomy for the treatment of pediatric urethral strictures: analysis of 50 patients. J Urol 2003; 170: 952. 8. Culty T and Boccon-Gibod L: Anastomotic urethroplasty for posttraumatic urethral stricture: previous urethral manipulation has a negative impact on the final outcome. J Urol 2007; 177: 1376.
9. Diamond DA, Xuewu J, Bauer SB et al: What is the optimal surgical strategy for bulbous urethral stricture in boys? J Urol 2009; 182: 1755. 10. Hafez AT, El-Assmy A, Sarhan O et al: Perineal anastomotic urethroplasty for managing posttraumatic urethral strictures in children: the longterm outcome. BJU Int 2005; 95: 403. 11. Fransis K, Vander Eeckt K, Van Poppel H et al: Results of buccal mucosa grafts for repairing long bulbar urethral strictures. BJU Int 2009; Epub ahead of print. 12. Peskar DB and Perovic AV: Comparison of radiographic and sonographic urethrography for assessing urethral strictures. Eur Radiol 2004; 14: 137.
Sonourethrogram to Manage Adolescent Anterior Urethral Stricture Edward M. Gong, Claudia Martinez Rios Arellano, Jeanne S. Chow and Richard S. Lee* From the Departments of Urology and Radiology (CMRZ, JSC), Children’s Hospital Boston, Boston, Massachusetts
Purpose: Accurate measurement of anterior urethral stricture length is critical to determine the appropriate surgical approach. Retrograde urethrogram is often used to determine stricture location and length. However, the adult literature shows that retrograde urethrogram may underestimate stricture length. We investigated the role of sonographic urethrogram in the preoperative evaluation of adolescent urethral stricture disease. Materials and Methods: Between June 2008 and February 2009 we retrospectively evaluated 12 pediatric patients with urethral stricture disease using retrograde and sonographic urethrogram. Stricture length was categorized by 2 radiologists as I—less than 1, II—1 to 3 and III— greater than 3 cm. On sonographic urethrogram stricture length was measured as the longest extent of the urethral abnormality. Results: Mean patient age was 16.9 years (range 9.5 to 20.8). Retrograde urethrogram classified 7 cases as category I, 4 as category II and none as category III stricture, and 1 with no evidence of stricture. Sonographic urethrogram revealed strictures greater than 1 cm in all 7 category I cases and 2 of the 4 category II cases had strictures longer than 3 cm. One patient in whom retrograde urethrogram showed a category II stricture was stricture-free on sonographic urethrogram. One patient with a negative retrograde urethrogram had a stricture on sonographic urethrogram. Sonographic urethrogram upgraded stricture length in 10 of the 12 patients and outperformed retrograde urethrogram in 11. Conclusions: Sonographic urethrogram is effective for evaluating adolescent urethral stricture disease. It may provide more accurate measurement of stricture length and improve preoperative planning.
Abbreviations and Acronyms DVIU ⫽ direct visual internal urethrotomy RUG ⫽ retrograde urethrography SUG ⫽ sonographic urethrography Study received institutional review board approval. * Correspondence: Department of Urology, Children’s Hospital Boston, 300 Longwood Ave., Hunnewell 390, Boston, Massachusetts 02115 (telephone: 617-355-7796; e-mail: richard.lee@ childrens.harvard.edu).
Key Words: urethra, urethral stricture, diagnostic imaging, ultrasonography, adolescent ANTERIOR urethral stricture disease presents with varying degrees of severity. Treatment includes minimally invasive endoscopic procedures and open surgical repair. Appropriate treatment for anterior urethral stricture disease depends on accurate measurement of stricture length. Endoscopic urethrotomy is more likely to be successful for strictures less than 1 cm
long.1 Urethroplasty is generally considered the standard for longer strictures.2 However, this depends on accurate imaging and measurement of urethral stricture length. Several studies indicate that in adults SUG may yield more accurate results to determine stricture length.3–5 This has not been well studied in the pediatric population and most practi-
0022-5347/10/1844-1699/0 THE JOURNAL OF UROLOGY® © 2010 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
Vol. 184, 1699-1702, October 2010 Printed in U.S.A. DOI:10.1016/j.juro.2010.03.074
AND
RESEARCH, INC.
www.jurology.com
1699
1700
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
tioners rely on RUG. We compared the efficacy of SUG vs RUG to determine urethral stricture length in an adolescent population.
METHODS We performed an institutional review board approved, retrospective evaluation of patients with identified stricture on RUG using SUG. Between June 2008 and February 2009, 12 patients with presumed urethral stricture disease underwent SUG. Only patients in the adolescent age group were included in analysis (median age 17 years, range 9 to 20). After urethral stricture disease diagnosis by RUG the patients underwent cystoscopy and SUG with a surgical plan to perform DVIU in those with stricture less than 1 cm long or open urethroplasty for longer strictures. SUG was done in the operating suite with the patient under general anesthesia in the dorsal lithotomy position. The attending surgeon, radiologist and ultrasound technician were present for the procedure. Initially the bladder was filled in retrograde fashion with placement of a small bore Foley catheter at the fossa navicularis unless a suprapubic tube was present. After sufficient bladder distention simultaneous retrograde and antegrade urethral distention was achieved by injecting saline via a catheter at the fossa navicularis and a Credé maneuver. We used a 15L8 ultrasound transducer (Siemens, Berkeley, California) at 14.0 MHz to visualize the urethra. The probe was placed on the perineum or site of the presumed stricture during active urethral distention until adequate visualization was achieved. On SUG strictures were identified by altered echogenicity, luminal narrowing and changes in periurethral tissue. Also, during real-time imaging of urethral strictures the attending surgeon could use the degree of urethral distention to determine functional stricture length. Including patient positioning and setup, ultrasound duration was 12 to 25 minutes. Regardless of severity, any degree of urethral abnormality was considered strictured tissue. Stricture length was measured by drawing perpendicular lines through the urethral lumen at the most proximal and most distal aspects of the urethral stricture. The longest length between these lines was measured at the urethral wall as stricture length (see figure). Using strict criteria, any evidence of fibrosis of urethral or periurethral tissue was considered part of the stricture. Depending on stricture length patients were grouped in 1 of 3 categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. These categories were selected in correlation with the change in treatment due to stricture length. Stricture length on SUG was measured with the assistance of 2 radiologists (the performing radiologist and JSC). Strictures on RUG were estimated by 2 radiologists (JSC and CMRA) to be in 1 of 3 identical categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. Strictures were confirmed surgically at cystoscopy or open surgery. The operative attending surgeon made the final decision on stricture management. Statistical analysis was done with SPSS®, version 14.0.
SUG measurement technique (double-headed arrow) (A) and corresponding RUG with similar stricture length (arrowheads) (B). RUG reveals short, tight stricture (arrowheads) (C), which was longer on SUG (arrowhead) (D).
RESULTS All 12 patients underwent RUG plus SUG. Mean ⫾ SD patient age at SUG was 16.9 ⫾ 3.2 years (range 9.5 to 20.8). Nine strictures were idiopathic, 2 were iatrogenic and 1 was traumatic. Before SUG 5 patients received no prior instrumentation while 2, 2, 2 and 1 underwent DVIU, dilation, suprapubic catheterization and transurethral resection for posterior urethral valves, respectively. All patients had a single stricture. The stricture site was bulbar in 8 cases, penile in 1 and penobulbar in 2. The presenting symptom was slow stream in 5 patients, hematuria in 4, dysuria in 4, and urinary retention and incontinence in 1 each. RUG classified 7 cases as category I, 4 as category II and none as category III stricture. One patient in whom urinary retention was treated with a suprapubic catheter had no stricture on RUG (see table). In contrast, on SUG there were no category I, 7 category II and 4 category III strictures with a mean length of 2.58 cm (range 1.0 to 4.4). Ten of the 12 cases (83.3%) were upgraded in category by SUG. In 1 of these patients with negative RUG who was suspected to have stricture disease due to symptoms SUG identified a 2.6 cm bulbar urethral stricture. Another patient thought to have a stricture on RUG was subsequently found to be stricture-free after SUG with cystoscopic confirmation. Only 1 patient remained in the same category. Including the case in which stricture was misdiagnosed by RUG, SUG outperformed RUG in 11 of 12 cases (91.7%) (see table). In 7 of the 12 patients (58.3%) planned surgery was changed based on SUG results. Also, SUG confirmed the decision to perform primary urethroplasty in 3 patients. All 7 patients in whom surgical
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
Patient demographics Plan RUG Category (pt No.)
SUG Category
Before SUG
After SUG
II II II II II III III
DVIU DVIU DVIU DVIU Urethroplasty DVIU DVIU
DVIU DVIU Urethroplasty Urethroplasty Urethroplasty Urethroplasty Urethroplasty
II III III None II
Dilation Urethroplasty Urethroplasty DVIU DVIU
Urethroplasty Urethroplasty Urethroplasty None Urethroplasty
I: 1 2 3 4 5 6 7 II: 8 9 10 11 None (12)
planning was changed were originally scheduled to undergo DVIU or urethral dilation. Six of the 7 patients underwent open urethroplasty and in the remaining patient no procedure was done since no stricture was identified on SUG. The remaining 2 patients in the study underwent DVIU.
DISCUSSION Management of anterior urethral strictures is controversial in the adult and pediatric populations. Longer, denser strictures are likely better treated with more aggressive open surgical techniques. Treating shorter, less dense strictures with an endoscopic technique may be more cost-effective.6 Some groups advocate initial DVIU regardless of preoperative stricture length, reserving urethroplasty for cases in which 1 endoscopic attempt has failed.7 Others argue that any previous urethral manipulation may have a detrimental effect on the outcome of open surgical repair.8 Diamond et al reported that open urethroplasty as the initial surgical approach has a higher overall success rate in the pediatric population.9 In adults Pansadora and Emiliozzi noted a 71% success rate for strictures less than 1 cm vs an 18% success rate for strictures greater than 1 cm when treated with DVIU.1 In a pediatric population Hafez et al reported an 89% success rate for primary perineal anastomotic urethroplasty with a mean urethral stricture length of 2.6 cm.10 Patients with even longer strictures (mean 3.2 cm) may be better treated with oral mucosa graft repair.11 Based on these reports we separated urethral strictures into 3 categories, including I—less than 1, II—1 to 3 and III— greater than 3 cm. RUG with voiding cystourethrography is the classic imaging technique in pediatric patients suspected of having urethral stricture disease. While
1701
RUG can detect urethral stricture disease, it does not provide information on the extent of spongiosal fibrosis and may be inaccurate for measurement. Recently in the adult literature SUG proved to be more beneficial to assess these characteristics.3–5 Gupta et al found that stricture length on SUG correlated better than that on RUG with length measured intraoperatively.5 Choudhary et al reported that RUG and SUG were equally sensitive and specific for strictures less than 1 and greater than 4 cm.3 However, for strictures between 1 and 4 cm SUG was more sensitive and more specific. Beyond the benefit of SUG to determine stricture length it also potentially provides additional information on the health of periurethral tissue.12 Our findings confirm the adult findings in an adolescent population. While most strictures measured on RUG were thought to be short (category I), SUG identified no category I strictures. All strictures were category II (7 cases) or III (4). Furthermore, SUG detected a significant stricture in a patient in whom RUG was negative. This misdiagnosis by RUG may have been secondary to poor radiograph exposure. SUG also ruled out stricture disease in a patient with worrisome narrowing on RUG. In this study direct length comparison between RUG and SUG was not possible. Exact RUG stricture length could not be determined. Without knowing precisely the distance from the x-ray source and sensor to the patient, direct measurement of stricture length was not possible. This is similar to the concept that only postero-anterior x-rays should be used to determine heart size since anteroposterior x-rays falsely increase heart size by moving the patient farther from the x-ray plate. Due to the retrospective nature of this study and to the different surgical approaches we did not measure exact intraoperative stricture length. Several surgeons did not include measured stricture length in the operative note and several did not measure intraoperative stricture length. These surgeons cut down directly on the area of palpable stricture and, using visual and tactile cues, extend the excised portion of the urethra proximal and distal until it is felt that no fibrotic tissue remains. Furthermore, since strictured tissue arrives piecemeal to pathologists, it was not possible to use histological analysis to determine stricture length. Another potential limitation of our study is a result of the increased sensitivity of SUG detection and our criteria for measuring stricture length. Peskar and Perovic attempted to account for this discrepancy by measuring 2 lengths on each SUG, including total urethral stricture length and the length of maximally reduced lumen.12 Although this measurement technique measures the maximally affected length, that length does not necessarily in-
1702
SONOURETHROGRAM TO MANAGE ADOLESCENT ANTERIOR URETHRAL STRICTURE
clude all tissue that requires surgical resection. We believe that direct communication between surgeon and ultrasonographer is important to arrive at a mutual determination of significant stricture. Intraoperative SUG after urethral exposure may further help determine the extent of disease. Although SUG is performed using anesthesia, it has an important role in assessing urethral stricture length in the pediatric population and it may potentially provide the critical information to determine the optimal corrective procedure. We recommend that SUG not be used as a screening tool to detect urethral stricture disease but rather as an adjunct in a treatment algorithm to determine the surgical
approach. Furthermore, the use of SUG should be evaluated for other urethral disorders in the pediatric population, such as post-hypospadiac stricture of the penile urethra.
CONCLUSIONS In this retrospective pilot study SUG in the adolescent population was a useful perioperative adjunct to RUG. SUG provided additional information on stricture length and periurethral fibrosis, and may help guide operative intervention. SUG may be useful in the diagnostic and perioperative evaluation of adolescent urethral stricture.
REFERENCES 1. Pansadora V and Emiliozzi P: Internal urethrotomy in the management of anterior urethral strictures: long-term followup. J Urol 1996; 156: 73. 2. Rourke KF and Jordan GH: Primary urethral reconstruction: the cost minimized approach to the bulbous urethral stricture. J Urol 2005; 173: 1206. 3. Choudhary S, Singh P, Sundar E et al: A comparison of sonourethrography and retrograde urethrography in evaluation of anterior urethral strictures. Clin Radiol 2004; 59: 736. 4. Gupta S, Majumdar B, Tiwari A et al: Sonourethrography in the evaluation of anterior urethral strictures: correlation with radiographic urethrography. J Clin Ultrasound 1993; 21: 231. 5. Gupta N, Dubey D, Mandhani A et al: Urethral stricture assessment: a prospective study evalu-
ating urethral ultrasonography and conventional radiological studies. BJU Int 2006; 98: 149. 6. Wright JL, Wessells H, Nathens AB et al: What is the most cost-effective treatment for 1 to 2-cm bulbar urethral strictures: societal approach using decision analysis. Urology 2006; 67: 889. 7. Hsiao KS, Baez-Trinidad L, Lendvay T et al: Direct vision internal urethrotomy for the treatment of pediatric urethral strictures: analysis of 50 patients. J Urol 2003; 170: 952. 8. Culty T and Boccon-Gibod L: Anastomotic urethroplasty for posttraumatic urethral stricture: previous urethral manipulation has a negative impact on the final outcome. J Urol 2007; 177: 1376.
9. Diamond DA, Xuewu J, Bauer SB et al: What is the optimal surgical strategy for bulbous urethral stricture in boys? J Urol 2009; 182: 1755. 10. Hafez AT, El-Assmy A, Sarhan O et al: Perineal anastomotic urethroplasty for managing posttraumatic urethral strictures in children: the longterm outcome. BJU Int 2005; 95: 403. 11. Fransis K, Vander Eeckt K, Van Poppel H et al: Results of buccal mucosa grafts for repairing long bulbar urethral strictures. BJU Int 2009; Epub ahead of print. 12. Peskar DB and Perovic AV: Comparison of radiographic and sonographic urethrography for assessing urethral strictures. Eur Radiol 2004; 14: 137.