- Email: [email protected]
Urinary Retention in Children
Pediatric Urology Urinary Retention in Children Amihay Nevo, Roy Mano, Pinhas M. Livne, Bezalel Sivan, and David Ben-Meir OBJECTIVE METHODS
RESULTS
CONCLUSION
To describe the causes and outcome of urinary retention in children and assess its prevalence by gender and age. The medical records of all children (aged <18 years) who presented to the emergency room with acute urinary retention from 2000 to 2012 were reviewed. Patients with postoperative urinary retention, a known neurologic disorder, and neonates were excluded. Data were collected on patient demographics and cause, treatment, and outcome of the urinary retention. Findings were evaluated and compared by age and gender. The study group comprised 42 boys (75%) and 14 girls (25%). Median follow-up time was 25 months. Causes of urinary retention were mechanical obstruction in 14 patients (25%), infection or inflammation in 10 (18%), fecal impaction in 7 (13%), neurologic disorders in 6 (11%), gynecologic disorders in 4 (7%), and behavioral processes in 3 patients (5%); 12 patients (21%) were idiopathic. All patients with mechanical obstruction were boys, of whom 5 had a pelvic tumor. Age distribution was bimodal: 29% of the events occurred between ages 3 and 5 years, and 32%, between ages 10 and 13 years. Fifteen children underwent surgery. Three children required continuous catheterization during follow-up. Urinary retention in children is characterized by a variable etiology and bimodal age distribution. The high rate of severe underlying disease is noteworthy and should alert physicians to the importance of a prompt, comprehensive, primary evaluation of this patient population in a hospital setting to initiate appropriate treatment and avoid complications. UROLOGY 84: 1475e1479, 2014. 2014 Elsevier Inc.
A
cute urinary retention is common in the adult male population and is most frequently related to prostatic enlargement.1 However, it is rarely encountered in children, in whom it has been associated with a wide variety of causes. Importantly, urinary retention may be a symptom of malignancy or other severe disease, which requires prompt diagnosis and treatment. Three previous studies of pediatric urinary retention, published in the last 2 decades, all reported similar mechanical, infectious, and neurologic etiologies, though with different rates of occurrence. Overall, cystitis, neurologic disturbances, and lower urinary tract stones seemed to be the most frequent.2-4 The distribution of the etiologies by age has not been widely studied. The aim of the present study was to investigate the etiology and outcome of urinary retention in children, and to assess its prevalence by gender and age.
METHODS After obtaining approval from our institutional ethics committee, we reviewed the medical records of all children admitted to Financial Disclosure: The authors declare that they have no relevant financial interests. From the Pediatric Urology Unit, Department of Pediatric Surgery, Schneider Children’s Medical Center of Israel, Petah Tikva, Israel; and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Address correspondence to: Amihay Nevo, M.D., Pediatric Urology Unit, Schneider Children’s Medical Center of Israel, 39 Jabotinski Street, Petach Tikva 49202, Israel. E-mail: [email protected] Submitted: July 2, 2014, accepted (with revisions): August 19, 2014
ª 2014 Elsevier Inc. All Rights Reserved
the urology unit of a tertiary pediatric medical center with an emergency room diagnosis of urinary retention from 2000 to 2012. Children with postoperative urinary retention, urinary retention after urethral instrumentation, a known neurologic disorder, and neonates were excluded from the study. It is our hospital’s practice to admit all patients presenting with urinary retention for further investigation and treatment. First, the urinary bladder is drained with a urethral or suprapubic catheter, and the residual volume is measured. An initial workup is then performed: a comprehensive physical examination including neurologic, lumbosacral and external genitalia examination, urinalysis, and complete blood count and chemistry panel. Ultrasonography, voiding cystourethrogram (VCUG), additional imaging tests, and urodynamic evaluation are performed as required. Similar to previous reports, we define urinary retention as the inability to void for >12 hours in the presence of a palpable bladder or a urine volume greater than expected for age ([age in years þ 2] [30 cc]).3 The cause is identified only on completion of all diagnostic testing. Urinary retention secondary to behavioral disturbances is diagnosed after exclusion of other possible etiologies and a psychological evaluation. Dysfunctional voiding was defined according to the International Children’s Continence Society terminology based on urodynamic studies or repeated uroflowmetry measurements.5 Fecal impaction was defined according to the Paris Consensus on Childhood Constipation Terminology Group as severe constipation with a large fecal mass in the rectum, which is unlikely to be passed on demand.6 For the present study, findings at initial presentation and treatment were retrieved from the emergency room’s medical database. Data on patient age and gender, medical history, http://dx.doi.org/10.1016/j.urology.2014.08.020 0090-4295/14
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Table 1. Etiologies of urinary retention stratified by patient gender Girls Etiology Mechanical Urethral stone Urethral stricture Urethral polyp Bladder diverticulum Phimosis Rhabdomyosarcoma Neuroblastoma Bladder neck polyp Infection and inflammation Cystitis Vaginitis HSV genitalis Meatitis Periappendicular abscess Infected urachal cyst Missed testicular torsion Fecal impaction Neurologic Dysfunctional voiding Myelitis Gynecologic Hematocolpos Labial adhesion Labial hematoma Behavioral Idiopathic Total
Total No. of Patients (%)
No. of Patients (%)
Boys Median Age (Range), y
14 (25)
10 (18)
2 (14)
15.8 (15-16.5)
1 (7) 1 (7)
16.5 15
7 (13) 6 (11)
3 (21) 2 (14) 2 (14)
4 (7)
4 1 2 1 1 2
3 (5) 12 (21) 56
(29) (7) (14) (7) (7) (14) 14
10 (3.8-11) 15 (13.9-16) 15 (13.9-16) 4 (3.8-15.5) 15.5 3.9 (3.8-4) 4 12.1 8.5 (2-15) 11.6 (15-16.5)
No. of Patients (%)
Median Age (Range), y
14 1 3 1 2 1 4 1 1 8 4
(33) (2) (7) (2) (5) (2) (10) (2) (2) (19) (10)
4.2 (0.6-16.2) 7 13 (13-16.2) 5 2.6 (0.6-4.5) 3 2.9 (0.8-3.8) 1.4 4.5 11.4 (2.5-16) 11.4 (2.5-14.5)
1 1 1 1 4 4 3 1
(2) (2) (2) (2) (10) (10) (7) (2)
4 11.6 3.2 16 8 (3.1-12.1) 9.6 (0.8-11.3) 8.5 (0.8-11.3) 11
2 (5) 10 (24) 42
12 (10-14) 11.5 (2.2-17) 10 (0.6-17)
HSV, herpes simplex virus.
duration of urinary retention, residual volume, diagnostic workup, final diagnosis, treatment, and follow-up were collected from the patients’ medical records. When follow-up information was lacking, the parents or guardians were contacted and interviewed with a telephone questionnaire. Clinical data were reported using descriptive statistics. The median and range were used for continuous variables. The chisquare test was used to analyze between-group differences in categorical variables. One-year intervals were used for analysis of age distribution. All statistical analyses were 2 sided and performed with SPSS Statistics, version 21.0 (IBM Corp., Armonk, NY). A P value <.05 was considered statistically significant.
RESULTS The study cohort included 56 children, 42 boys (75%) and 14 girls (25%) of median age 10.5 years (range, 0.617 years). Thirty-eight children (68%) presented with an initial episode of urinary retention, and 18 (32%) with a recurrent episode, including 14 boys (78%) and 4 girls (22%). There are approximately 55,000 emergency room visits to our institute every year; therefore, the mean annual incidence rate of urinary retention was 8.48 cases per 100,000 children presenting to the emergency room. Mechanical obstruction was the most common cause of urinary retention, identified in 14 children (25%), all of whom were boys. Five of the 14 children (36%) had a pelvic tumor: rhabdomyosarcoma of the bladder or prostate in 4 children (80%) and pelvic neuroblastoma in 1 1476
child (20%). The others had urethral stones, strictures or polyps, bladder diverticulum, phimosis, or bladder neck polyps. An infectious or inflammatory etiology was identified in 10 children (18%): 4 boys with cystitis and 1 boy each with meatitis, periappendicular abscess, missed torsion of the testis, and infected urachal cyst. The other 2 patients, both girls, had vaginitis or herpes simplex virus genitalis. Additional causes were fecal impaction in 7 children (13%), neurologic disorders in 6 children (11%), and gynecologic disorders in 4 children (7%). Behavioral disturbances were found in 3 children (5%). The remaining 12 children (21%) were diagnosed with idiopathic urinary retention. The etiologies and their distribution by gender are listed in Table 1. The age distribution of the cohort was bimodal: 29% of the events occurred between ages 3 and 5 years, and 32%, between ages 10 and 13 years (Fig. 1). The etiology of urinary retention categorized by age is listed in Table 2. A significant difference in etiologies was found when the patients were categorized by age above or below 10 years (P ¼ .036): Children with mechanical obstruction were more often <10 years old, whereas children with behavioral or idiopathic causes were more often older. All children with acute urinary retention due to a malignant tumor were <4 years old. Ultrasonography, performed in 36 of 56 children (64%), was the most common imaging modality used for the evaluation of urinary retention. Magnetic resonance UROLOGY 84 (6), 2014
Figure 1. Incidence of urinary retention stratified by age. Table 2. Age distribution of etiologies of urinary retention Etiology Mechanical Idiopathic Behavioral Fecal impaction Infection and inflammation Gynecologic Neurologic Total
0-9 Y, n (%) 10-18 Y, n (%) Total, n (%) 11 (44) 3 (12) 0 3 (12) 3 (12) 3 (12) 2 (8) 25
3 9 3 4 7
(10) (29) (10) (13) (23)
1 (3) 4 (13) 31
14 12 3 7 10
(25) (21) (5) (13) (18)
4 (7) 6 (11) 56
imaging (MRI) was used in 14 of 56 children (25%); notably, 5 of 6 children (83%) with urinary retention caused by neurologic disorders were diagnosed with MRI. VCUG, abdominal x-ray, and computed tomography were less commonly performed for the evaluation of urinary retention (12 of 56, 7 of 56, and 6 of 56 children, respectively). Urodynamic studies and cystoscopy were used more often when behavioral etiologies were identified to exclude other diagnoses. The median follow-up time was 25 months (range, 1 month-16 years). During this period, 15 children underwent surgical procedures: 12 with a mechanical obstruction, 1 girl with hematocolpos secondary to an imperforated hymen, 1 boy with dysfunctional voiding treated by augmentation cystoplasty, and 1 boy with Hirschsprung disease treated by transanal pull-through resection of the rectum. Eighteen patients had recurrent episodes of urinary retention during follow-up. The etiology of recurrent urinary retention was mechanical in 4 patients, neurologic in 3, infection and inflammation in 3, idiopathic in 3, behavioral in 2, fecal impaction in 2, and gynecologic in 1 patient. Recurrent urinary retention was apparent in 2 of 3 patients with behavioral etiology and 3 of 6 patients with neurologic etiology. Three of the total 56 children (5%) required clean intermittent catheterization during follow-up: the boy after augmentation cystoplasty and 1 boy and 1 girl with behavioral disturbances.
COMMENT The present study describes a series of children who presented to the emergency room of a single pediatric medical center with acute urinary retention. Mechanical UROLOGY 84 (6), 2014
obstruction was the most prevalent cause. A considerable proportion of the children had a severe underlying disease necessitating immediate diagnosis and treatment. In addition, we noted a bimodal age distribution, and stratification of the patients by age and gender yielded significant differences in the etiologies of the urinary retention. Three series of pediatric urinary retention have been published in the medical literature to date.2-4 The most prevalent causes were instrumentation or surgery followed by cystitis in the study by Peter and Steinhardt2 (35 children), neurologic disorders (17%) in the study by Gatti et al3 (53 children), and urinary tract stones (28%) in the study by Asgari et al4 (86 children). By contrast, in the present series, highest rates were found for mechanical obstruction, idiopathic urinary retention, and infectious or inflammatory processes. The differences in etiology may reflect unique features of the specific cohorts or differences in patient inclusion and exclusion criteria. In our cohort, mechanical obstruction affected 14 children (25%), all boys, of whom 5 (9% of all causes of urinary retention) had a malignant neoplasm (rhabdomyosarcoma in 4 and neuroblastoma in 1 patient). In previous reports, rhabdomyosarcoma was identified in only 1.1%-3.7% of patients.3,4 A study of rhabdomyosarcoma of the bladder or prostate in children found acute urinary retention to be a frequent clinical presentation. Additional signs and symptoms included urinary frequency, stranguria, and hematuria. In the bladder, rhabdomyosarcomas usually have a botryoid appearance and grow intraluminally at or near the trigone, obstructing the bladder outlet. Prostatic tumors tend to present as solid masses compressing the bladder wall.7 The outcome of children with rhabdomyosarcoma of the bladder or prostate has improved significantly in recent decades; the reported overall 6-year survival rate is 82% when a multimodal treatment approach is used. Patients with advanced disease have a poorer prognosis and a lower likelihood of bladder preservation; therefore, early diagnosis and treatment are crucial.8 In our series, the rhabdomyosarcoma in all 4 cases was palpable on digital rectal examination, but only in 1 case on abdominal examination, emphasizing the importance of physical examination as part of the initial evaluation of urinary retention in children. Treatment consisted of chemotherapy and brachytherapy or external beam radiotherapy with surgery (2 cases) or without it (2 cases). One child died of the disease. Acute urinary retention associated with a pelvic neuroblastoma was described in a few case reports, possibly attributable to displacement of the bladder base by the tumor with infiltration of the sacral plexus.9 Another 3 children in the present cohort with mechanical obstruction had an idiopathic posterior urethral stricture, which was diagnosed with VCUG; all were male patients, aged 13-16 years. Urethral strictures are uncommon and are almost always secondary to previous surgery or trauma.10 Given the homogeneous characteristics of the children, we speculate that they may have 1477
experienced an earlier missed urethral injury. Urethral self instrumentation is another plausible explanation. One child presented with urinary retention due to phimosis. After initial drainage, he underwent circumcision, which resulted in complete voiding, thus confirming the diagnosis. Infectious or inflammatory processes were the cause of urinary retention in 10 children (18%). These included cystitis in 4 children, all of whom were, unexpectedly, boys. Previous studies have attributed some cases of urinary retention to local inflammation, but the underlying mechanism was not clear. Edema of the bladder wall can lead to bladder outlet obstruction; impaired contraction, decreased end-organ response to neurologic stimuli, and volitional avoidance of voiding may also play a role. Meatitis and vaginitis, found in 1 child each, can cause obstruction via the same mechanism as cystitis. One boy each had a periappendicular abscess, missed torsion of the testis, or infected urachal cyst. Accordingly, others found that acute urinary retention is a rare and unusual presentation of appendicitis. The presence of an inflammatory mass at a perivesical location may provoke urinary retention by local or reflex pathways.11 Infected urachal cysts were previously reported as a cause of urinary retention in a single series of patients.12 Balanoposthitis, a common cause of urinary retention, is a rare event in our country, where the vast majority of children are circumcised. Fecal impaction was the cause of urinary retention in 7 children. Constipation and lower urinary tract symptoms are common in children, and they often coexist. Although constipation is most often described in association with nocturnal enuresis, incontinence, urinary tract infections, and vesicoureteral reflux, it may also play a role in urinary retention.13,14 Again, the mechanisms underlying this relationship remain unclear. Possible explanations include bladder compression and obstruction by a distended rectum, similar gastrointestinal and lower urinary tract neurologic pathways, inappropriate pelvic floor muscle contraction with external urethral sphincter hyperactivity or dyssynergia, a common neuromuscular disorder affecting each system, and stool and urine withholding as a manifestation of behavioral disturbances.15 Fecal impaction in our series was initially treated with enemas. All the children in this group were evaluated by a multidisciplinary team including a pediatric neurologist and gastroenterologist. One girl who presented with fecal impaction, urinary retention, and urinary tract infection required clean intermittent catheterization for a prolonged period until resolution. One boy was eventually diagnosed with Hirschsprung disease and underwent transanal pull-through resection of the rectum. The remaining 5 children diagnosed with fecal impaction had a single episode of urinary retention and did not require further investigation. Neurologic causes of urinary retention were relatively less common in our study. One child was diagnosed with transverse myelitis. He was treated with immunosuppressive 1478
medications and is currently symptom-free after 4 years of follow-up. Dysfunctional voiding, the result of impaired coordination between detrusor contraction and sphincter relaxation, can be diagnosed by urodynamic studies, demonstrating detrusor-sphincter dyssynergia or by the presence of interrupted urine flow on repeated uroflowmetry measurements.5 Two children were diagnosed with dysfunctional voiding by urodynamic studies. Treatment included reassurance, lifestyle modification, encouraging regular voiding habits, biofeedback, and cognitive behavioral therapy. Differentiating these cases from fecal impaction can be challenging in a retrospective study because of the possible overlap between the 2 conditions. One patient in this group had constipation and urinary retention; however, rectal biopsy for suspected Hirschsprung disease was negative, and his urinary complaints persisted after obtaining regular bowel movement. A relatively high rate of patients with neurologic urinary retention (50%) had recurrent episodes of retention during follow-up. Four girls presented with acute urinary retention due to a gynecologic disorder. Two girls presented with labial adhesions, a common finding in the prepubertal age. Both were initially treated with gentle spreading of the labia and application of topical estrogen cream. One girl had recurrent episodes of urinary retention and urinary tract infection despite eventual surgical repair, questioning the underlying etiology of the retention. One girl had an imperforate hymen and hematocolpos, a rare cause of urinary retention and often misdiagnosed as a pelvic mass compressing the bladder and urethra.16 Behavioral disturbances were the least common cause of urinary retention in our study. Three children were diagnosed after exclusion of other possible etiologies and a psychological evaluation. One child had obsessive compulsive disorder, and the 2 others had poor social background leading to severe emotional stress. Two of the patients had repeated events. Although more frequent in adults, psychogenic urinary retention has been described in children. It warrants urinary rehabilitation with intermittent catheterization, bladder training, and supportive psychotherapy.17 Twenty-one percent of our cohort was diagnosed with idiopathic urinary retention. Findings on physical examination, urinalysis, and blood tests were all normal. Children with a single episode of urinary retention were discharged for follow-up. Three children with recurrent idiopathic urinary retention underwent further imaging and urodynamic tests, which were noncontributory. The urinary retention resolved spontaneously in all 3 children. The high rate of idiopathic cases may be a result of the difficulty in identifying the etiology of urinary retention. Viral infection is not usually evaluated as a cause of urinary retention. The main culprits include cytomegalovirus, herpes simplex virus, and adenovirus.18 Cases often resolve spontaneously. We did not test for these agents in our study. Hollow visceral myopathy is a rare entity that should also be considered. However, the vast majority of UROLOGY 84 (6), 2014
these patients have severe anatomic, functional, and clinical manifestations.19 Our analysis of patient age revealed that the number of cases peaked from ages 3 to 5 years and from ages 10 to 13 years. Furthermore, there was a significant difference in the etiology of urinary retention depending on the age and gender. Mechanical obstruction was more common in boys aged <10 years, and behavioral or idiopathic causes were more common in older boys and girls. These findings are consistent with previous reports in which benign and malignant obstructing lesions occurred solely in boys at a mean age of 2 and 3 years.2,3 The most commonly used imaging modality for evaluating the cause of urinary retention was ultrasonography, followed by MRI. Computed tomography and x-ray, which involve exposure to radiation, were less frequently used. Further prospective studies are required to define the optimal evaluation algorithm for children with urinary retention. Our study is limited by its retrospective design. There may also have been a selection bias as the study was conducted in a tertiary referral center, thereby, automatically excluding children diagnosed and treated in the community by their primary physician. In addition, documentation of any pharmacologic therapy that could have caused urinary retention (cold medication, antihistamines, and neuroleptic drugs) was lacking. However, it is unlikely that this was the cause in a significant number of these children. Finally, as our goal was to evaluate the cause of urinary retention in children without predisposing factors in the emergency room setting, we excluded children with postoperative urinary retention, a known neurologic disorder, and neonates. Including these, patients may have affected our results and altered the prevalence of the various etiologies.
CONCLUSION Urinary retention in children has various etiologies and a bimodal age distribution. It is often associated with severe underlying disorders, which, left untreated, may have serious consequences. Most alarming is the relatively high rate of malignant neoplasms (9%). Therefore, timely diagnosis is warranted. Unless there is an obvious cause of the urinary retention, a comprehensive primary evaluation is necessary in a hospital setting, including neurologic and rectal examination, urinalysis, blood tests, and imaging.
UROLOGY 84 (6), 2014
References 1. Lepor H. Managing and preventing acute urinary retention. Rev Urol. 2005;7(suppl 8):S26-33. 2. Peter JR, Steinhardt GF. Acute urinary retention in children. Pediatr Emerg Care. 1993;9:205-207. 3. Gatti JM, Perez-Brayfield M, Kirsch AJ, et al. Acute urinary retention in children. J Urol. 2001;165:918-921. 4. Asgari SA, Mansour Ghanaie M, Simforoosh N, et al. Acute urinary retention in children. Urol J. 2005;2:23-27. 5. Neveus T, von Gontard A, Hoebeke P, et al. The standardization of terminology of lower urinary tract function in children and adolescents: report from the Standardisation Committee of the International Children’s Continence Society. J Urol. 2006;176:314-324. 6. Benninga M, Candy DC, Catto-Smith AG, et al. The Paris Consensus on Childhood Constipation Terminology (PACCT) Group. J Pediatr Gastroenterol Nutr. 2005;40:273-275. 7. Hays DM, Raney RB Jr, Lawrence W Jr, et al. Bladder and prostatic tumors in the intergroup Rhabdomyosarcoma study (IRS-I): results of therapy. Cancer. 1982;50:1472-1482. 8. Ferrer FA, Isakoff M, Koyle MA. Bladder/prostate rhabdomyosarcoma: past, present and future. J Urol. 2006;176:1283-1291. 9. Rasmussen A, Muniz AE, King B. Neuroblastoma causing acute urinary retention: a rare presentation. J Emerg Med. 2010;39: 602-606. 10. Hafez AT, El-Assmy A, Dawaba MS, et al. Long-term outcome of visual internal urethrotomy for the management of pediatric urethral strictures. J Urol. 2005;173:595-597. 11. Noble J, Culkin DJ, Willis S, et al. Acute urinary retention in a child with appendiceal abscess: diagnostic dilemma. Urology. 1990; 36:513-515. 12. Quicios Dorado C, Fernandez Fernandez E, Gomez Garcia I, et al. [Urachal cyst presenting as acute urinary retention]. Actas Urol Esp. 2005;29:909-912. 13. Koff SA, Wagner TT, Jayanthi VR. The relationship among dysfunctional elimination syndromes, primary vesicoureteral reflux and urinary tract infections in children. J Urol. 1998;160: 1019-1022. 14. Bakker E, van Sprundel M, van der Auwera JC, et al. Voiding habits and wetting in a population of 4,332 Belgian schoolchildren aged between 10 and 14 years. Scand J Urol Nephrol. 2002;36: 354-362. 15. Burgers R, Liem O, Canon S, et al. Effect of rectal distention on lower urinary tract function in children. J Urol. 2010;184: 1680-1685. 16. Adali E, Kurdoglu M, Yildizhan R, et al. An overlooked cause of acute urinary retention in an adolescent girl: a case report. Arch Gynecol Obstet. 2009;279:701-703. 17. Wan KS, Liu NH, Liu CK, et al. Psychogenic urinary retention in children: a case report. Pediatr Neonatol. 2010;51:300-302. 18. Shih SL, Liu YP, Tsai JD, et al. Acute urinary retention in a 7-yearold girl: an unusual complication of cytomegalovirus cystitis. J Pediatr Surg. 2008;43:e37-e39. 19. Ghavamian R, Wilcox DT, Duffy PG, et al. The urological manifestations of hollow visceral myopathy in children. J Urol. 1997;158: 1286-1290.
1479
RESULTS
CONCLUSION
To describe the causes and outcome of urinary retention in children and assess its prevalence by gender and age. The medical records of all children (aged <18 years) who presented to the emergency room with acute urinary retention from 2000 to 2012 were reviewed. Patients with postoperative urinary retention, a known neurologic disorder, and neonates were excluded. Data were collected on patient demographics and cause, treatment, and outcome of the urinary retention. Findings were evaluated and compared by age and gender. The study group comprised 42 boys (75%) and 14 girls (25%). Median follow-up time was 25 months. Causes of urinary retention were mechanical obstruction in 14 patients (25%), infection or inflammation in 10 (18%), fecal impaction in 7 (13%), neurologic disorders in 6 (11%), gynecologic disorders in 4 (7%), and behavioral processes in 3 patients (5%); 12 patients (21%) were idiopathic. All patients with mechanical obstruction were boys, of whom 5 had a pelvic tumor. Age distribution was bimodal: 29% of the events occurred between ages 3 and 5 years, and 32%, between ages 10 and 13 years. Fifteen children underwent surgery. Three children required continuous catheterization during follow-up. Urinary retention in children is characterized by a variable etiology and bimodal age distribution. The high rate of severe underlying disease is noteworthy and should alert physicians to the importance of a prompt, comprehensive, primary evaluation of this patient population in a hospital setting to initiate appropriate treatment and avoid complications. UROLOGY 84: 1475e1479, 2014. 2014 Elsevier Inc.
A
cute urinary retention is common in the adult male population and is most frequently related to prostatic enlargement.1 However, it is rarely encountered in children, in whom it has been associated with a wide variety of causes. Importantly, urinary retention may be a symptom of malignancy or other severe disease, which requires prompt diagnosis and treatment. Three previous studies of pediatric urinary retention, published in the last 2 decades, all reported similar mechanical, infectious, and neurologic etiologies, though with different rates of occurrence. Overall, cystitis, neurologic disturbances, and lower urinary tract stones seemed to be the most frequent.2-4 The distribution of the etiologies by age has not been widely studied. The aim of the present study was to investigate the etiology and outcome of urinary retention in children, and to assess its prevalence by gender and age.
METHODS After obtaining approval from our institutional ethics committee, we reviewed the medical records of all children admitted to Financial Disclosure: The authors declare that they have no relevant financial interests. From the Pediatric Urology Unit, Department of Pediatric Surgery, Schneider Children’s Medical Center of Israel, Petah Tikva, Israel; and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Address correspondence to: Amihay Nevo, M.D., Pediatric Urology Unit, Schneider Children’s Medical Center of Israel, 39 Jabotinski Street, Petach Tikva 49202, Israel. E-mail: [email protected] Submitted: July 2, 2014, accepted (with revisions): August 19, 2014
ª 2014 Elsevier Inc. All Rights Reserved
the urology unit of a tertiary pediatric medical center with an emergency room diagnosis of urinary retention from 2000 to 2012. Children with postoperative urinary retention, urinary retention after urethral instrumentation, a known neurologic disorder, and neonates were excluded from the study. It is our hospital’s practice to admit all patients presenting with urinary retention for further investigation and treatment. First, the urinary bladder is drained with a urethral or suprapubic catheter, and the residual volume is measured. An initial workup is then performed: a comprehensive physical examination including neurologic, lumbosacral and external genitalia examination, urinalysis, and complete blood count and chemistry panel. Ultrasonography, voiding cystourethrogram (VCUG), additional imaging tests, and urodynamic evaluation are performed as required. Similar to previous reports, we define urinary retention as the inability to void for >12 hours in the presence of a palpable bladder or a urine volume greater than expected for age ([age in years þ 2] [30 cc]).3 The cause is identified only on completion of all diagnostic testing. Urinary retention secondary to behavioral disturbances is diagnosed after exclusion of other possible etiologies and a psychological evaluation. Dysfunctional voiding was defined according to the International Children’s Continence Society terminology based on urodynamic studies or repeated uroflowmetry measurements.5 Fecal impaction was defined according to the Paris Consensus on Childhood Constipation Terminology Group as severe constipation with a large fecal mass in the rectum, which is unlikely to be passed on demand.6 For the present study, findings at initial presentation and treatment were retrieved from the emergency room’s medical database. Data on patient age and gender, medical history, http://dx.doi.org/10.1016/j.urology.2014.08.020 0090-4295/14
1475
Table 1. Etiologies of urinary retention stratified by patient gender Girls Etiology Mechanical Urethral stone Urethral stricture Urethral polyp Bladder diverticulum Phimosis Rhabdomyosarcoma Neuroblastoma Bladder neck polyp Infection and inflammation Cystitis Vaginitis HSV genitalis Meatitis Periappendicular abscess Infected urachal cyst Missed testicular torsion Fecal impaction Neurologic Dysfunctional voiding Myelitis Gynecologic Hematocolpos Labial adhesion Labial hematoma Behavioral Idiopathic Total
Total No. of Patients (%)
No. of Patients (%)
Boys Median Age (Range), y
14 (25)
10 (18)
2 (14)
15.8 (15-16.5)
1 (7) 1 (7)
16.5 15
7 (13) 6 (11)
3 (21) 2 (14) 2 (14)
4 (7)
4 1 2 1 1 2
3 (5) 12 (21) 56
(29) (7) (14) (7) (7) (14) 14
10 (3.8-11) 15 (13.9-16) 15 (13.9-16) 4 (3.8-15.5) 15.5 3.9 (3.8-4) 4 12.1 8.5 (2-15) 11.6 (15-16.5)
No. of Patients (%)
Median Age (Range), y
14 1 3 1 2 1 4 1 1 8 4
(33) (2) (7) (2) (5) (2) (10) (2) (2) (19) (10)
4.2 (0.6-16.2) 7 13 (13-16.2) 5 2.6 (0.6-4.5) 3 2.9 (0.8-3.8) 1.4 4.5 11.4 (2.5-16) 11.4 (2.5-14.5)
1 1 1 1 4 4 3 1
(2) (2) (2) (2) (10) (10) (7) (2)
4 11.6 3.2 16 8 (3.1-12.1) 9.6 (0.8-11.3) 8.5 (0.8-11.3) 11
2 (5) 10 (24) 42
12 (10-14) 11.5 (2.2-17) 10 (0.6-17)
HSV, herpes simplex virus.
duration of urinary retention, residual volume, diagnostic workup, final diagnosis, treatment, and follow-up were collected from the patients’ medical records. When follow-up information was lacking, the parents or guardians were contacted and interviewed with a telephone questionnaire. Clinical data were reported using descriptive statistics. The median and range were used for continuous variables. The chisquare test was used to analyze between-group differences in categorical variables. One-year intervals were used for analysis of age distribution. All statistical analyses were 2 sided and performed with SPSS Statistics, version 21.0 (IBM Corp., Armonk, NY). A P value <.05 was considered statistically significant.
RESULTS The study cohort included 56 children, 42 boys (75%) and 14 girls (25%) of median age 10.5 years (range, 0.617 years). Thirty-eight children (68%) presented with an initial episode of urinary retention, and 18 (32%) with a recurrent episode, including 14 boys (78%) and 4 girls (22%). There are approximately 55,000 emergency room visits to our institute every year; therefore, the mean annual incidence rate of urinary retention was 8.48 cases per 100,000 children presenting to the emergency room. Mechanical obstruction was the most common cause of urinary retention, identified in 14 children (25%), all of whom were boys. Five of the 14 children (36%) had a pelvic tumor: rhabdomyosarcoma of the bladder or prostate in 4 children (80%) and pelvic neuroblastoma in 1 1476
child (20%). The others had urethral stones, strictures or polyps, bladder diverticulum, phimosis, or bladder neck polyps. An infectious or inflammatory etiology was identified in 10 children (18%): 4 boys with cystitis and 1 boy each with meatitis, periappendicular abscess, missed torsion of the testis, and infected urachal cyst. The other 2 patients, both girls, had vaginitis or herpes simplex virus genitalis. Additional causes were fecal impaction in 7 children (13%), neurologic disorders in 6 children (11%), and gynecologic disorders in 4 children (7%). Behavioral disturbances were found in 3 children (5%). The remaining 12 children (21%) were diagnosed with idiopathic urinary retention. The etiologies and their distribution by gender are listed in Table 1. The age distribution of the cohort was bimodal: 29% of the events occurred between ages 3 and 5 years, and 32%, between ages 10 and 13 years (Fig. 1). The etiology of urinary retention categorized by age is listed in Table 2. A significant difference in etiologies was found when the patients were categorized by age above or below 10 years (P ¼ .036): Children with mechanical obstruction were more often <10 years old, whereas children with behavioral or idiopathic causes were more often older. All children with acute urinary retention due to a malignant tumor were <4 years old. Ultrasonography, performed in 36 of 56 children (64%), was the most common imaging modality used for the evaluation of urinary retention. Magnetic resonance UROLOGY 84 (6), 2014
Figure 1. Incidence of urinary retention stratified by age. Table 2. Age distribution of etiologies of urinary retention Etiology Mechanical Idiopathic Behavioral Fecal impaction Infection and inflammation Gynecologic Neurologic Total
0-9 Y, n (%) 10-18 Y, n (%) Total, n (%) 11 (44) 3 (12) 0 3 (12) 3 (12) 3 (12) 2 (8) 25
3 9 3 4 7
(10) (29) (10) (13) (23)
1 (3) 4 (13) 31
14 12 3 7 10
(25) (21) (5) (13) (18)
4 (7) 6 (11) 56
imaging (MRI) was used in 14 of 56 children (25%); notably, 5 of 6 children (83%) with urinary retention caused by neurologic disorders were diagnosed with MRI. VCUG, abdominal x-ray, and computed tomography were less commonly performed for the evaluation of urinary retention (12 of 56, 7 of 56, and 6 of 56 children, respectively). Urodynamic studies and cystoscopy were used more often when behavioral etiologies were identified to exclude other diagnoses. The median follow-up time was 25 months (range, 1 month-16 years). During this period, 15 children underwent surgical procedures: 12 with a mechanical obstruction, 1 girl with hematocolpos secondary to an imperforated hymen, 1 boy with dysfunctional voiding treated by augmentation cystoplasty, and 1 boy with Hirschsprung disease treated by transanal pull-through resection of the rectum. Eighteen patients had recurrent episodes of urinary retention during follow-up. The etiology of recurrent urinary retention was mechanical in 4 patients, neurologic in 3, infection and inflammation in 3, idiopathic in 3, behavioral in 2, fecal impaction in 2, and gynecologic in 1 patient. Recurrent urinary retention was apparent in 2 of 3 patients with behavioral etiology and 3 of 6 patients with neurologic etiology. Three of the total 56 children (5%) required clean intermittent catheterization during follow-up: the boy after augmentation cystoplasty and 1 boy and 1 girl with behavioral disturbances.
COMMENT The present study describes a series of children who presented to the emergency room of a single pediatric medical center with acute urinary retention. Mechanical UROLOGY 84 (6), 2014
obstruction was the most prevalent cause. A considerable proportion of the children had a severe underlying disease necessitating immediate diagnosis and treatment. In addition, we noted a bimodal age distribution, and stratification of the patients by age and gender yielded significant differences in the etiologies of the urinary retention. Three series of pediatric urinary retention have been published in the medical literature to date.2-4 The most prevalent causes were instrumentation or surgery followed by cystitis in the study by Peter and Steinhardt2 (35 children), neurologic disorders (17%) in the study by Gatti et al3 (53 children), and urinary tract stones (28%) in the study by Asgari et al4 (86 children). By contrast, in the present series, highest rates were found for mechanical obstruction, idiopathic urinary retention, and infectious or inflammatory processes. The differences in etiology may reflect unique features of the specific cohorts or differences in patient inclusion and exclusion criteria. In our cohort, mechanical obstruction affected 14 children (25%), all boys, of whom 5 (9% of all causes of urinary retention) had a malignant neoplasm (rhabdomyosarcoma in 4 and neuroblastoma in 1 patient). In previous reports, rhabdomyosarcoma was identified in only 1.1%-3.7% of patients.3,4 A study of rhabdomyosarcoma of the bladder or prostate in children found acute urinary retention to be a frequent clinical presentation. Additional signs and symptoms included urinary frequency, stranguria, and hematuria. In the bladder, rhabdomyosarcomas usually have a botryoid appearance and grow intraluminally at or near the trigone, obstructing the bladder outlet. Prostatic tumors tend to present as solid masses compressing the bladder wall.7 The outcome of children with rhabdomyosarcoma of the bladder or prostate has improved significantly in recent decades; the reported overall 6-year survival rate is 82% when a multimodal treatment approach is used. Patients with advanced disease have a poorer prognosis and a lower likelihood of bladder preservation; therefore, early diagnosis and treatment are crucial.8 In our series, the rhabdomyosarcoma in all 4 cases was palpable on digital rectal examination, but only in 1 case on abdominal examination, emphasizing the importance of physical examination as part of the initial evaluation of urinary retention in children. Treatment consisted of chemotherapy and brachytherapy or external beam radiotherapy with surgery (2 cases) or without it (2 cases). One child died of the disease. Acute urinary retention associated with a pelvic neuroblastoma was described in a few case reports, possibly attributable to displacement of the bladder base by the tumor with infiltration of the sacral plexus.9 Another 3 children in the present cohort with mechanical obstruction had an idiopathic posterior urethral stricture, which was diagnosed with VCUG; all were male patients, aged 13-16 years. Urethral strictures are uncommon and are almost always secondary to previous surgery or trauma.10 Given the homogeneous characteristics of the children, we speculate that they may have 1477
experienced an earlier missed urethral injury. Urethral self instrumentation is another plausible explanation. One child presented with urinary retention due to phimosis. After initial drainage, he underwent circumcision, which resulted in complete voiding, thus confirming the diagnosis. Infectious or inflammatory processes were the cause of urinary retention in 10 children (18%). These included cystitis in 4 children, all of whom were, unexpectedly, boys. Previous studies have attributed some cases of urinary retention to local inflammation, but the underlying mechanism was not clear. Edema of the bladder wall can lead to bladder outlet obstruction; impaired contraction, decreased end-organ response to neurologic stimuli, and volitional avoidance of voiding may also play a role. Meatitis and vaginitis, found in 1 child each, can cause obstruction via the same mechanism as cystitis. One boy each had a periappendicular abscess, missed torsion of the testis, or infected urachal cyst. Accordingly, others found that acute urinary retention is a rare and unusual presentation of appendicitis. The presence of an inflammatory mass at a perivesical location may provoke urinary retention by local or reflex pathways.11 Infected urachal cysts were previously reported as a cause of urinary retention in a single series of patients.12 Balanoposthitis, a common cause of urinary retention, is a rare event in our country, where the vast majority of children are circumcised. Fecal impaction was the cause of urinary retention in 7 children. Constipation and lower urinary tract symptoms are common in children, and they often coexist. Although constipation is most often described in association with nocturnal enuresis, incontinence, urinary tract infections, and vesicoureteral reflux, it may also play a role in urinary retention.13,14 Again, the mechanisms underlying this relationship remain unclear. Possible explanations include bladder compression and obstruction by a distended rectum, similar gastrointestinal and lower urinary tract neurologic pathways, inappropriate pelvic floor muscle contraction with external urethral sphincter hyperactivity or dyssynergia, a common neuromuscular disorder affecting each system, and stool and urine withholding as a manifestation of behavioral disturbances.15 Fecal impaction in our series was initially treated with enemas. All the children in this group were evaluated by a multidisciplinary team including a pediatric neurologist and gastroenterologist. One girl who presented with fecal impaction, urinary retention, and urinary tract infection required clean intermittent catheterization for a prolonged period until resolution. One boy was eventually diagnosed with Hirschsprung disease and underwent transanal pull-through resection of the rectum. The remaining 5 children diagnosed with fecal impaction had a single episode of urinary retention and did not require further investigation. Neurologic causes of urinary retention were relatively less common in our study. One child was diagnosed with transverse myelitis. He was treated with immunosuppressive 1478
medications and is currently symptom-free after 4 years of follow-up. Dysfunctional voiding, the result of impaired coordination between detrusor contraction and sphincter relaxation, can be diagnosed by urodynamic studies, demonstrating detrusor-sphincter dyssynergia or by the presence of interrupted urine flow on repeated uroflowmetry measurements.5 Two children were diagnosed with dysfunctional voiding by urodynamic studies. Treatment included reassurance, lifestyle modification, encouraging regular voiding habits, biofeedback, and cognitive behavioral therapy. Differentiating these cases from fecal impaction can be challenging in a retrospective study because of the possible overlap between the 2 conditions. One patient in this group had constipation and urinary retention; however, rectal biopsy for suspected Hirschsprung disease was negative, and his urinary complaints persisted after obtaining regular bowel movement. A relatively high rate of patients with neurologic urinary retention (50%) had recurrent episodes of retention during follow-up. Four girls presented with acute urinary retention due to a gynecologic disorder. Two girls presented with labial adhesions, a common finding in the prepubertal age. Both were initially treated with gentle spreading of the labia and application of topical estrogen cream. One girl had recurrent episodes of urinary retention and urinary tract infection despite eventual surgical repair, questioning the underlying etiology of the retention. One girl had an imperforate hymen and hematocolpos, a rare cause of urinary retention and often misdiagnosed as a pelvic mass compressing the bladder and urethra.16 Behavioral disturbances were the least common cause of urinary retention in our study. Three children were diagnosed after exclusion of other possible etiologies and a psychological evaluation. One child had obsessive compulsive disorder, and the 2 others had poor social background leading to severe emotional stress. Two of the patients had repeated events. Although more frequent in adults, psychogenic urinary retention has been described in children. It warrants urinary rehabilitation with intermittent catheterization, bladder training, and supportive psychotherapy.17 Twenty-one percent of our cohort was diagnosed with idiopathic urinary retention. Findings on physical examination, urinalysis, and blood tests were all normal. Children with a single episode of urinary retention were discharged for follow-up. Three children with recurrent idiopathic urinary retention underwent further imaging and urodynamic tests, which were noncontributory. The urinary retention resolved spontaneously in all 3 children. The high rate of idiopathic cases may be a result of the difficulty in identifying the etiology of urinary retention. Viral infection is not usually evaluated as a cause of urinary retention. The main culprits include cytomegalovirus, herpes simplex virus, and adenovirus.18 Cases often resolve spontaneously. We did not test for these agents in our study. Hollow visceral myopathy is a rare entity that should also be considered. However, the vast majority of UROLOGY 84 (6), 2014
these patients have severe anatomic, functional, and clinical manifestations.19 Our analysis of patient age revealed that the number of cases peaked from ages 3 to 5 years and from ages 10 to 13 years. Furthermore, there was a significant difference in the etiology of urinary retention depending on the age and gender. Mechanical obstruction was more common in boys aged <10 years, and behavioral or idiopathic causes were more common in older boys and girls. These findings are consistent with previous reports in which benign and malignant obstructing lesions occurred solely in boys at a mean age of 2 and 3 years.2,3 The most commonly used imaging modality for evaluating the cause of urinary retention was ultrasonography, followed by MRI. Computed tomography and x-ray, which involve exposure to radiation, were less frequently used. Further prospective studies are required to define the optimal evaluation algorithm for children with urinary retention. Our study is limited by its retrospective design. There may also have been a selection bias as the study was conducted in a tertiary referral center, thereby, automatically excluding children diagnosed and treated in the community by their primary physician. In addition, documentation of any pharmacologic therapy that could have caused urinary retention (cold medication, antihistamines, and neuroleptic drugs) was lacking. However, it is unlikely that this was the cause in a significant number of these children. Finally, as our goal was to evaluate the cause of urinary retention in children without predisposing factors in the emergency room setting, we excluded children with postoperative urinary retention, a known neurologic disorder, and neonates. Including these, patients may have affected our results and altered the prevalence of the various etiologies.
CONCLUSION Urinary retention in children has various etiologies and a bimodal age distribution. It is often associated with severe underlying disorders, which, left untreated, may have serious consequences. Most alarming is the relatively high rate of malignant neoplasms (9%). Therefore, timely diagnosis is warranted. Unless there is an obvious cause of the urinary retention, a comprehensive primary evaluation is necessary in a hospital setting, including neurologic and rectal examination, urinalysis, blood tests, and imaging.
UROLOGY 84 (6), 2014
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