Pediatric Case Report Congenital Anterior Urethral Diverticulum: Antenatal Diagnosis With Subsequent Neonatal Endoscopic Management Ahmed Adam, Michael Myint, Sean E. Kennedy, Elizabeth Dally, and Daniel Challis Congenital anterior urethral diverticulum is a rare cause of urethral obstruction in boys. We report on the antenatal diagnosis of this rare phenomenon, making this the sixth prenatally diagnosed case in the English literature (to the best of our knowledge). Our initial prenatal assessment, postnatal endoscopic management, along with the eventual clinical course is outlined. The embryologic theories, differential diagnosis, literature review, imaging, and treatment modalities of this entity are discussed. UROLOGY 85: 914e917, 2015. 2015 Elsevier Inc.
C
ongenital anterior urethral diverticulum (CAUD) is a rare cause of urethral obstruction in boys.1 We report a case of antenatally diagnosed CAUD associated with unilateral renal loss who underwent endoscopic management in early infancy.
CASE REPORT A 30-year-old primigravida was referred at 28 weeks with the provisional diagnosis of lower urinary tract obstruction on antenatal fetal ultrasound. The following features were documented: anhydramnios, marked bilateral hydroureteronephrosis, distended bladder, and a dilated midurethral segment (Fig. 1A-C). Serial fetal bladder taps documented mixed prognosis fetal urinary electrolytes (Osmol: 266; 177 mmol/kg, Na: 128; 63 mmol/L, B2 microglobulin: 23.4; 20.8 mg/L). Therefore, a decision was made not to offer vesicoamniotic shunting. During the follow-up ultrasound study (31-week gestation), it appeared that the bladder outlet obstruction caused by CAUD had spontaneously resolved. However, hydronephrosis of the right kidney had persisted. An elective caesarean section was performed at term for a frank breech presentation. Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Paediatric Urology, Sydney Children’s Hospital, Randwick, Sydney, Australia; the Department of Paediatric Urology, Children’s Hospital at Westmead, Westmead, Sydney, Australia; the School of Women’s & Children’s Health, UNSW Medicine, University of New South Wales, Sydney, Australia; Department of Nephrology, Sydney Children's Hospital, Randwick, Sydney, Australia; the Australian Centre for Perinatal Science, UNSW Medicine, University of New South Wales, Australia; and the Department of Maternal Fetal Medicine, Royal Hospital for Women, Randwick, Sydney, Australia Address correspondence to: Ahmed Adam, M.B.B.Ch., Dip.P.E.C. (SA), F.C. Urol. (SA), M.Med. (Urol.) (Pretoria), Department of Paediatric Urology, Sydney Children’s Hospital, 3 High Street, Randwick, Sydney, New South Wales, 2031, Australia. E-mail: [email protected] Submitted: August 26, 2014, accepted (with revisions): December 8, 2014
914
ª 2015 Elsevier Inc. All Rights Reserved
The initial newborn assessment was unremarkable, except for a distinct ventral penile swelling, which enlarged on voiding and could be easily emptied with “urethral milking.” Ultrasound scan performed at birth revealed a small dysplastic left kidney (below the fifth centile) with a thick-walled bladder. The right kidney appeared normal apart from mild pelvicalyceal dilatation. The serum creatinine level was 46 mmol/L at 2 weeks of age. MAG-3 renogram study confirmed the presence of a nonfunctioning left kidney. Antibiotic prophylaxis was initiated, but because a normalized serum creatinine level along with spontaneous voiding was present, endoscopic evaluation was deferred for a later setting. At week 3 of life, he subsequently developed pyelonephritis caused by Enterobacter cloacae and responded well to intravenous therapy. A cystourethrogram defined the CAUD in the anterior urethra (Fig. 2) and cystourethroscopy confirmed the presence of a large diverticulum in the anterior urethra (Fig. 3B). Vesicoureteric reflux (VUR) grade 4 had been demonstrated on the left nonfunctioning system. At 4 weeks of age, transurethral resection of the CAUD was performed with complete excision of the distal lip of the CAUD using a transurethral resection blade (Fig. 3C, Video 1). The surgical recovery was unremarkable except for a postobstructive diuresis (8 mL/kg/ h), which was managed accordingly. The serum creatinine level returned to 30 mmol/L. The patient presented with a coagulase-negative staphylococcus urosepsis 3 months later. Renal function deteriorated with serum creatinine level reaching 171 mmol/L and renal ultrasound revealing worsening right-sided hydroureteronephrosis. Treatment with intravenous antibiotics was successfully instituted, with cutaneous vesicostomy diversion. http://dx.doi.org/10.1016/j.urology.2014.12.015 0090-4295/15
Figure 1. Antenatal ultrasound scan (28-week gestation), showing (A) bilateral hydronephrosis, (B) distended bladder (Bl.), and (C) congenital anterior urethral diverticulum (*)—perineal view, showing longitudinal view of the penis between the pubic bones. (Color version available online.)
COMMENT
Figure 2. Cystourethrogram outlining the congenital anterior urethral diverticulum (*).
Recovery post vesicostomy was unremarkable with ongoing prophylactic antibiotics. We are planning for a definitive open urethral reconstruction and circumcision once feasible. UROLOGY 85 (4), 2015
CAUD is a rare condition that may result in significant obstructive uropathy.1,2 Although rarely reported, CAUD may be detected antenatally.3 Ladwig et al4 reported the first case of antenatally diagnosed CAUD in 2005. A subsequent case was reported in combination with multiple other urethral anomalies.5 A recent published series of antenatal diagnosis of CAUD, reviewed their experience with 3 patients.3 Herein, we describe the sixth report of CAUD to be diagnosed in the antenatal period. Features of urethral distension should be sought in all cases presenting with apparent lower urinary tract obstruction on prenatal ultrasound. CAUD should be suspected if features of a midline cystic scrotal mass or cystic dilatation of the urethral mid segment are present.1,3 Distinguishing CAUD from posterior urethral valvular obstruction is achieved by determining a lack of continuity between the urethral dilatation and bladder.3 Signs of obstructive uropathy associated with CAUD include hydroureteronephrosis, bladder distension, and oligohydramnios (all present in our index case). It is also possible that fetal urinary electrolyte assessment may not be useful or predictive of subsequent renal function in this underlying condition. Common postnatal presenting features of CAUD include a compressible ventral penile swelling, urinary 915
Figure 3. (A) Ventral penile swelling that enlarged with voiding, representing the diverticulum (white arrow), (B) endoscopic view of the roof of the diverticulum, and (C) transurethral resection of the diverticulum. (Color version available online.)
dribble postmicturition, voiding difficulty, poor stream, and recurrent urinary tract infections.2,4,6 CAUD may result in significant obstructive uropathy with secondary renal dysfunction.4 The distal lip in CAUD may be confused with an anterior urethral valve (AUV), as their diagnosis is often overlapped.7,8 A deficient or divergent corpus spongiosum in CAUD is a differentiating factor between AUV and CAUD because patients with an isolated AUV have normal corpus spongiosum.3,8,9 Radiologic differentiation can also be made with AUV having an obtuse angle between the proximal AUV and the ventral floor, whereas the proximal lip of CAUD forms an acute angle with the ventral floor.8,10 In CAUD, the cause of obstruction in a “gate-action” mechanism is caused by the distal lip obstructing urine flow as it is forced against the roof of the urethra with distension of the diverticulum.1,11 Theories on the embryology of CAUD are unclear and include dilatation of the periurethral glands, sequestration of epithelial cells after urethral fold closure, and a deficient and divergent corpus spongiosum.7,9 Other theories postulated include ruptured syringocoele as well as incomplete hypospadias.7 Retrograde urethrography, micturating cystourethrography, and cystrourethroscopy are all investigative modalities that can be used in defining the anterior urethral diverticulum.4,12 Early treatment of CAUD is important to prevent complications including recurrent urinary tract infections and renal dysfunction.7,10 The role of a circumcision has proven beneficial in patients presenting with VUR within the first year of life, with Alsaywid et al, showing that a circumcision resulted in fewer urinary tract infections and a lower incidence of 916
new permanent defects (5.2% vs 10.2%).13 The use of a dorsal slit may also be considered in this scenario, which may have the added advantage of preserving the prepucial tissue for use in the formal repair. Treatment should be tailored to the individual patient and guided by findings on investigation. Transurethral intervention of CAUD by incision or deroofing of the distal lip of the diverticulum should be attempted, if possible.1 However, this method requires sufficient caliber of the urethra for safe instrumentation.1 There is also a risk of the lip redeveloping because of continued presence of diverticulum pouch despite incision.12 Scar tissue formation and resultant stricture may lead to persistent obstruction after initial incision of the distal lip of the CAUD.12 In cases of urosepsis and obstructive uropathy, urinary diversion with vesicostomy or suprapubic catheterization can be implemented before definitive surgical management.12 As an alternative to the cutaneous vesicostomy (in patients without VUR), a proximal cutaneous urethrostomy may be used. This has the added advantage of maintaining the physiological bladder function during the “waiting period.”8 Open surgical repair may be the most definitive curative option and should be performed as soon as feasible.8,11
CONCLUSION We present a rare case of CAUD diagnosed in the antenatal period. Although CAUD is a rare cause of urethral obstruction, it may lead to severe obstructive uropathy and significant urosepsis. Initial management should focus on the exact underlying pathology and may include endoscopic resection, with progression to diversion and open surgical reconstruction, if needed. With improvements in UROLOGY 85 (4), 2015
prenatal scanning, we postulate that antenatal detection of this rare condition will be reported more frequently if sonographic features of urethral distension are sought. Early diagnosis and appropriate treatment can limit possible complications associated with CAUD and may prove life saving. Acknowledgment. The authors are grateful to Ms Amy Howat (Associate Genetic Counselor, Maternal Fetal Medicine, Royal Hospital for Women, Randwick, Sydney, Australia) for her assistance with the prenatal imaging and records. References 1. Smith GH, Deshpande AV, Tang RW. Uncommon causes of anterior urethral diverticula in children: two cases and review of literature. Urol Ann. 2014;6:75-79. 2. Rawat J, Khan TR, Singh S, et al. Congenital anterior urethral valves and diverticula: diagnosis and management in six cases. Afr J Paediatr Surg. 2009;6:102-105. 3. Coplen DE, Austin PF. Prenatal diagnosis and neonatal management of congenital urethral diverticulum. J Urol. 2007;177: 2330-2332. 4. Ladwig D, McNally G, Warren P, et al. Antenatal sonographic findings of congenital anterior urethral diverticulum. Ultrasound Obstetrics Gynecol. 2005;25:202-203.
UROLOGY 85 (4), 2015
5. Ranawaka R, Dickson A. Multiple urethral anomalies: anterior urethral diverticulum, posterior urethral valves, and distal hypospadias. J Pediatr Surg. 2013;48:e5-e8. 6. Howieson AJ, MacKinlay GA. Giant anterior urethral diverticulum in a neonate. J Pediatr Surg. 2007;42:735-736. 7. McLellan DL, Gaston MV, Diamond DA, et al. Anterior urethral valves and diverticula in children: a result of ruptured Cowper’s duct cyst? BJU Int. 2004;94:375-378. 8. Cruz-Diaz O, Salomon A, Rosenberg E, et al. Anterior urethral valves: not such a benign condition.. Front Pediatr. 2013;1:35. 9. Zia-ul-Miraj M. Congenital anterior urethral diverticula in children. Pediatr Surg Int. 1999;15:567-569. 10. Kadian YS, Rattan KN, Singh M, et al. Congenital anterior urethral diverticulum in children: a case report and review. ISRN Surg. 2011; 2011:120307. 11. Bhatnagar V, Lal R, Mitra DK. Primary reconstruction of a congenital anterior urethral diverticulum. Paediatr Surg Int. 1999;15:294-295. 12. Quoraishi SH, Khan F, Besarani D, et al. Congenital anterior urethral diverticulum in a male teenager: a case report and review of the literature. Case Rep Urol. 2011;2011:738638. 13. Alsaywid BS, Saleh H, Deshpande A, et al. High grade primary vesicoureteral reflux in boys: long-term results of a prospective cohort study. J Urol. 2010;184(4 suppl):1598-1603.
Supplementary data associated with this article can be found, in the online version, at http:// dx.doi.org/10.1016/j.urology.2014.12.015.
917
C
ongenital anterior urethral diverticulum (CAUD) is a rare cause of urethral obstruction in boys.1 We report a case of antenatally diagnosed CAUD associated with unilateral renal loss who underwent endoscopic management in early infancy.
CASE REPORT A 30-year-old primigravida was referred at 28 weeks with the provisional diagnosis of lower urinary tract obstruction on antenatal fetal ultrasound. The following features were documented: anhydramnios, marked bilateral hydroureteronephrosis, distended bladder, and a dilated midurethral segment (Fig. 1A-C). Serial fetal bladder taps documented mixed prognosis fetal urinary electrolytes (Osmol: 266; 177 mmol/kg, Na: 128; 63 mmol/L, B2 microglobulin: 23.4; 20.8 mg/L). Therefore, a decision was made not to offer vesicoamniotic shunting. During the follow-up ultrasound study (31-week gestation), it appeared that the bladder outlet obstruction caused by CAUD had spontaneously resolved. However, hydronephrosis of the right kidney had persisted. An elective caesarean section was performed at term for a frank breech presentation. Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Paediatric Urology, Sydney Children’s Hospital, Randwick, Sydney, Australia; the Department of Paediatric Urology, Children’s Hospital at Westmead, Westmead, Sydney, Australia; the School of Women’s & Children’s Health, UNSW Medicine, University of New South Wales, Sydney, Australia; Department of Nephrology, Sydney Children's Hospital, Randwick, Sydney, Australia; the Australian Centre for Perinatal Science, UNSW Medicine, University of New South Wales, Australia; and the Department of Maternal Fetal Medicine, Royal Hospital for Women, Randwick, Sydney, Australia Address correspondence to: Ahmed Adam, M.B.B.Ch., Dip.P.E.C. (SA), F.C. Urol. (SA), M.Med. (Urol.) (Pretoria), Department of Paediatric Urology, Sydney Children’s Hospital, 3 High Street, Randwick, Sydney, New South Wales, 2031, Australia. E-mail: [email protected] Submitted: August 26, 2014, accepted (with revisions): December 8, 2014
914
ª 2015 Elsevier Inc. All Rights Reserved
The initial newborn assessment was unremarkable, except for a distinct ventral penile swelling, which enlarged on voiding and could be easily emptied with “urethral milking.” Ultrasound scan performed at birth revealed a small dysplastic left kidney (below the fifth centile) with a thick-walled bladder. The right kidney appeared normal apart from mild pelvicalyceal dilatation. The serum creatinine level was 46 mmol/L at 2 weeks of age. MAG-3 renogram study confirmed the presence of a nonfunctioning left kidney. Antibiotic prophylaxis was initiated, but because a normalized serum creatinine level along with spontaneous voiding was present, endoscopic evaluation was deferred for a later setting. At week 3 of life, he subsequently developed pyelonephritis caused by Enterobacter cloacae and responded well to intravenous therapy. A cystourethrogram defined the CAUD in the anterior urethra (Fig. 2) and cystourethroscopy confirmed the presence of a large diverticulum in the anterior urethra (Fig. 3B). Vesicoureteric reflux (VUR) grade 4 had been demonstrated on the left nonfunctioning system. At 4 weeks of age, transurethral resection of the CAUD was performed with complete excision of the distal lip of the CAUD using a transurethral resection blade (Fig. 3C, Video 1). The surgical recovery was unremarkable except for a postobstructive diuresis (8 mL/kg/ h), which was managed accordingly. The serum creatinine level returned to 30 mmol/L. The patient presented with a coagulase-negative staphylococcus urosepsis 3 months later. Renal function deteriorated with serum creatinine level reaching 171 mmol/L and renal ultrasound revealing worsening right-sided hydroureteronephrosis. Treatment with intravenous antibiotics was successfully instituted, with cutaneous vesicostomy diversion. http://dx.doi.org/10.1016/j.urology.2014.12.015 0090-4295/15
Figure 1. Antenatal ultrasound scan (28-week gestation), showing (A) bilateral hydronephrosis, (B) distended bladder (Bl.), and (C) congenital anterior urethral diverticulum (*)—perineal view, showing longitudinal view of the penis between the pubic bones. (Color version available online.)
COMMENT
Figure 2. Cystourethrogram outlining the congenital anterior urethral diverticulum (*).
Recovery post vesicostomy was unremarkable with ongoing prophylactic antibiotics. We are planning for a definitive open urethral reconstruction and circumcision once feasible. UROLOGY 85 (4), 2015
CAUD is a rare condition that may result in significant obstructive uropathy.1,2 Although rarely reported, CAUD may be detected antenatally.3 Ladwig et al4 reported the first case of antenatally diagnosed CAUD in 2005. A subsequent case was reported in combination with multiple other urethral anomalies.5 A recent published series of antenatal diagnosis of CAUD, reviewed their experience with 3 patients.3 Herein, we describe the sixth report of CAUD to be diagnosed in the antenatal period. Features of urethral distension should be sought in all cases presenting with apparent lower urinary tract obstruction on prenatal ultrasound. CAUD should be suspected if features of a midline cystic scrotal mass or cystic dilatation of the urethral mid segment are present.1,3 Distinguishing CAUD from posterior urethral valvular obstruction is achieved by determining a lack of continuity between the urethral dilatation and bladder.3 Signs of obstructive uropathy associated with CAUD include hydroureteronephrosis, bladder distension, and oligohydramnios (all present in our index case). It is also possible that fetal urinary electrolyte assessment may not be useful or predictive of subsequent renal function in this underlying condition. Common postnatal presenting features of CAUD include a compressible ventral penile swelling, urinary 915
Figure 3. (A) Ventral penile swelling that enlarged with voiding, representing the diverticulum (white arrow), (B) endoscopic view of the roof of the diverticulum, and (C) transurethral resection of the diverticulum. (Color version available online.)
dribble postmicturition, voiding difficulty, poor stream, and recurrent urinary tract infections.2,4,6 CAUD may result in significant obstructive uropathy with secondary renal dysfunction.4 The distal lip in CAUD may be confused with an anterior urethral valve (AUV), as their diagnosis is often overlapped.7,8 A deficient or divergent corpus spongiosum in CAUD is a differentiating factor between AUV and CAUD because patients with an isolated AUV have normal corpus spongiosum.3,8,9 Radiologic differentiation can also be made with AUV having an obtuse angle between the proximal AUV and the ventral floor, whereas the proximal lip of CAUD forms an acute angle with the ventral floor.8,10 In CAUD, the cause of obstruction in a “gate-action” mechanism is caused by the distal lip obstructing urine flow as it is forced against the roof of the urethra with distension of the diverticulum.1,11 Theories on the embryology of CAUD are unclear and include dilatation of the periurethral glands, sequestration of epithelial cells after urethral fold closure, and a deficient and divergent corpus spongiosum.7,9 Other theories postulated include ruptured syringocoele as well as incomplete hypospadias.7 Retrograde urethrography, micturating cystourethrography, and cystrourethroscopy are all investigative modalities that can be used in defining the anterior urethral diverticulum.4,12 Early treatment of CAUD is important to prevent complications including recurrent urinary tract infections and renal dysfunction.7,10 The role of a circumcision has proven beneficial in patients presenting with VUR within the first year of life, with Alsaywid et al, showing that a circumcision resulted in fewer urinary tract infections and a lower incidence of 916
new permanent defects (5.2% vs 10.2%).13 The use of a dorsal slit may also be considered in this scenario, which may have the added advantage of preserving the prepucial tissue for use in the formal repair. Treatment should be tailored to the individual patient and guided by findings on investigation. Transurethral intervention of CAUD by incision or deroofing of the distal lip of the diverticulum should be attempted, if possible.1 However, this method requires sufficient caliber of the urethra for safe instrumentation.1 There is also a risk of the lip redeveloping because of continued presence of diverticulum pouch despite incision.12 Scar tissue formation and resultant stricture may lead to persistent obstruction after initial incision of the distal lip of the CAUD.12 In cases of urosepsis and obstructive uropathy, urinary diversion with vesicostomy or suprapubic catheterization can be implemented before definitive surgical management.12 As an alternative to the cutaneous vesicostomy (in patients without VUR), a proximal cutaneous urethrostomy may be used. This has the added advantage of maintaining the physiological bladder function during the “waiting period.”8 Open surgical repair may be the most definitive curative option and should be performed as soon as feasible.8,11
CONCLUSION We present a rare case of CAUD diagnosed in the antenatal period. Although CAUD is a rare cause of urethral obstruction, it may lead to severe obstructive uropathy and significant urosepsis. Initial management should focus on the exact underlying pathology and may include endoscopic resection, with progression to diversion and open surgical reconstruction, if needed. With improvements in UROLOGY 85 (4), 2015
prenatal scanning, we postulate that antenatal detection of this rare condition will be reported more frequently if sonographic features of urethral distension are sought. Early diagnosis and appropriate treatment can limit possible complications associated with CAUD and may prove life saving. Acknowledgment. The authors are grateful to Ms Amy Howat (Associate Genetic Counselor, Maternal Fetal Medicine, Royal Hospital for Women, Randwick, Sydney, Australia) for her assistance with the prenatal imaging and records. References 1. Smith GH, Deshpande AV, Tang RW. Uncommon causes of anterior urethral diverticula in children: two cases and review of literature. Urol Ann. 2014;6:75-79. 2. Rawat J, Khan TR, Singh S, et al. Congenital anterior urethral valves and diverticula: diagnosis and management in six cases. Afr J Paediatr Surg. 2009;6:102-105. 3. Coplen DE, Austin PF. Prenatal diagnosis and neonatal management of congenital urethral diverticulum. J Urol. 2007;177: 2330-2332. 4. Ladwig D, McNally G, Warren P, et al. Antenatal sonographic findings of congenital anterior urethral diverticulum. Ultrasound Obstetrics Gynecol. 2005;25:202-203.
UROLOGY 85 (4), 2015
5. Ranawaka R, Dickson A. Multiple urethral anomalies: anterior urethral diverticulum, posterior urethral valves, and distal hypospadias. J Pediatr Surg. 2013;48:e5-e8. 6. Howieson AJ, MacKinlay GA. Giant anterior urethral diverticulum in a neonate. J Pediatr Surg. 2007;42:735-736. 7. McLellan DL, Gaston MV, Diamond DA, et al. Anterior urethral valves and diverticula in children: a result of ruptured Cowper’s duct cyst? BJU Int. 2004;94:375-378. 8. Cruz-Diaz O, Salomon A, Rosenberg E, et al. Anterior urethral valves: not such a benign condition.. Front Pediatr. 2013;1:35. 9. Zia-ul-Miraj M. Congenital anterior urethral diverticula in children. Pediatr Surg Int. 1999;15:567-569. 10. Kadian YS, Rattan KN, Singh M, et al. Congenital anterior urethral diverticulum in children: a case report and review. ISRN Surg. 2011; 2011:120307. 11. Bhatnagar V, Lal R, Mitra DK. Primary reconstruction of a congenital anterior urethral diverticulum. Paediatr Surg Int. 1999;15:294-295. 12. Quoraishi SH, Khan F, Besarani D, et al. Congenital anterior urethral diverticulum in a male teenager: a case report and review of the literature. Case Rep Urol. 2011;2011:738638. 13. Alsaywid BS, Saleh H, Deshpande A, et al. High grade primary vesicoureteral reflux in boys: long-term results of a prospective cohort study. J Urol. 2010;184(4 suppl):1598-1603.
Supplementary data associated with this article can be found, in the online version, at http:// dx.doi.org/10.1016/j.urology.2014.12.015.
917
