Single system ureteral ectopia in boys associated with bladder outlet obstruction

PURPOSE: Ureteral ectopia is frequently associated with dysplasia of the associated renal segment in girls with ureteral duplication. However, single system ureteral ectopia is an uncommon anomaly more frequently noted in boys. We report on 6 boys with single system ureteral ectopia into the prostatic urethra above the verumontanum, who presented with radiological and clinical findings of bladder outlet obstruction. MATERIALS AND METHODS: Antenatal ultrasound in 3 boys demonstrated renal abnormalities and postnatal studies suggested the diagnosis of posterior urethral valve obstruction. Older boys presented with symptoms suggestive of bladder outlet obstruction. RESULTS: An ectopic ureter inserting into the prostatic urethra was noted in all 6 boys. The distal ureter was dilated elevating the bladder neck causing outlet obstruction. Surgical management consisted of nephrectomy and transurethral endoscopic incision of the distal ureter or nephroureterectomy with reconstruction of the prostatic urethra. In 2 younger boys voiding dysfunction with inability to empty developed. CONCLUSIONS: Single system ectopic ureters in boys may present with symptomatic and radiological findings resembling posterior urethral valves. Surgical treatment should include nephroureterectomy with reconstruction of the hypoplastic prostate. Some patients may have later voiding dysfunction.     

Laparoscopic nephrectomy for a single-system ectopic ureter draining a small, dysplastic and poorly functioning kidney in children

PURPOSES: To assess the efficacy of laparoscopic nephrectomy for a single-system ectopic ureter draining a dysplastic kidney in children. PATIENTS AND METHODS: Between February 1999 and September 2005, 16 girls with a mean age of 6.2 years (range: 2-15 years) presented with urinary incontinence accompanied by regular voiding since birth (15 patients) and vaginitis (one patient). Ultrasonography, intravenous urography and a 99mTc-DMSA renal scan showed the presence of only a single kidney in all cases. Computed tomography (CT) showed a dysplastic kidney definitely in nine patients, structures suspicious of dysplastic kidney in three cases, and no dysplastic kidney in four cases. Magnetic resonance imaging was carried out in the four cases with non-visualized dysplastic kidneys by CT, and showed a suspicious lesion in only one case, and no lesion in the other three patients. All patients underwent transperitoneal laparoscopic nephrectomy for a dysplastic kidney. RESULTS: Laparoscopy identifies all dysplastic kidneys easily, even in those cases in which dystrophic kidney could not be identified by preoperative imaging. Dysplastic kidneys and ectopic ureters were removed successfully in all 16 patients. Mean operative time was 109 min (range: 40-155 min) with little intraoperative bleeding. Mean postoperative hospital stay was 2.6 days (range: 2-4 days). No intraoperative complication was encountered, except in one single case, in which a small bowel injury occurred during open Hasson's procedure. All patients became dry soon after the operation. CONCLUSION: Laparoscopic nephrectomy for an ectopic ureter draining into a dysplastic kidney is a safe and effective method, and can be carried out successfully, despite a failure by preoperative imaging studies to localize the dysplastic kidney.     

Ectopic ureter in 54 children

PURPOSE: We reviewed 54 pediatric patients with ectopic ureter treated at our institution from 1975 to 1999. MATERIALS AND METHODS: Our series comprised 40 female and 14 male children, with age from 1 month to 11 years. Clinical records of the patients were reviewed retrospectively. RESULTS: Chief complaint was urinary incontinence in 24, high fever in 18, abdominal mass in 6, scrotal swelling in 3 and growth retardation in 2 patients. Two patients were found to have ectopic ureters without symptom during urological work-ups for their anorectal anomaly. The ectopic ureters opened into vagina in 19, vestibulum in 8, bladder neck in 7, urethra in 17, seminal vesicle in 2 and ejaculatory duct in 1 patient (s). Treatment was ureterocystoneostomy in 30, nephroureterectomy in 19, hemi-nephroureterectomy in 2, and ureteral ligature in 1 patient (s). Postoperatively, most of the patients became symptom free except for 6 patients in whom urinary incontinence was not cured due to mal-development of the bladder neck and sphincter, and due to Gartner's duct cyst. CONCLUSION: Urinary incontinence and urinary tract infection are most frequent presentations of ectopic ureter in children. Although most of the patients are cured with ureterocystoneostomy or nephroureterectomy, some incontinent girls continue to have urinary incontinence due to mal-development of the bladder neck and sphincter or Gartner's duct cyst.     

Bladder dysfunction in children with bilateral single ectopic ureters

Background: Single ectopic ureters are a rare malformation in children. Therapy consists of ureteral reimplantation. However, in case of bilateral single ectopic ureters, subsequent malformation of the bladder trigone and bladder neck may result in additional voiding dysfunction, and ureteral reimplantation alone may not solve the urologic problems. Methods: The authors report their experience with 2 girls, in whom bilateral single ectopic ureters were treated by ureteral reimplantation in early childhood and who did not gain adequate bladder control during following years. Results: Videourodynamic evaluation was done in both girls. No bladder overactivity was found during the urodynamic studies. However, cystography showed a widely open bladder neck during filling with no sufficient bladder neck closure shown by urethral pressure profile studies. When blocking the bladder outlet by balloon catheters, adequate bladder filling volume was achieved. Incontinence was cured by implantation of an AMS 800 artificial sphincter system in a 10-year-old girl. A 7-year-old girl was regarded to be too young for sphincter implantation and is waiting for surgery within the next years. Conclusion: Insufficient development of trigone and bladder neck with subsequent urinary incontinence has to be kept in mind when deciding on surgical procedures in children with bilateral single ectopic ureters.     

Partial Bladder Transplantation with En Bloc Kidney Transplant—The First Case Report of a 'Bladder Patch Technique' in a Human

Transplantation of the urinary bladder has not been reported in humans. We transplanted a portion of the donor bladder with an en bloc kidney graft in a 12-month-old girl. The child had a congenital hypoplastic single kidney with an ectopic ureteral opening into the vagina. Her native bladder was extremely small. Bilateral kidneys were transplanted en bloc with their ureters connected to a patch of the donor bladder, which encompassed the bilateral ureterovesical junctions (UVJs) (bladder patch technique). Approximately one-third of the donor bladder wall was used. The bladder patch reperfused well via blood supply from the ureters. Posttransplant cystoscopy with retrograde cystogram revealed a viable transplanted bladder with normal emptying of transplanted ureters. No reflux across the donor UVJs was seen in a voiding cystourethrogram. The child is doing well with normal renal function at 18-month follow-up.     

Ectopic ureterocele: results of open surgical therapy in 40 patients

PURPOSE: The treatment of ectopic ureterocele is controversial. In addition to debate on optimal therapy, discussion exists on whether there is further risk of deteriorating bladder function after extensive bladder surgery during the first year of life, which is a reason to postpone surgery. In a prospective nonrandomized trial we treated 40 patients regardless of age who had ectopic ureterocele with complete surgical reconstruction of the lower urinary tract and upper pole resection of poorly functioning upper pole moieties at referral. Excluded from study were 3 patients with only 1 affected renal moiety initially. MATERIALS AND METHODS: We treated 31 female and 9 male patients 0 to 8.8 years old (mean age 2.17) at surgery for ectopic ureterocele extending into the bladder neck and urethra, including 19 younger than 1 year. Primary ureterocele excision was performed in 37 cases with reconstruction of the urethra, bladder neck and trigone, and ureteral reimplantation. Because of small ureterocele size, the ureterocele was left in situ in 3 patients, leading to secondary ureterocele removal due to obstructive voiding and urinary incontinence in 1 each. A staged procedure in 5 neonates involved primary lower urinary tract reconstruction with upper pole cutaneous ureterostomies followed by upper pole resection or ureteral reimplantation a few months later. After bladder neck reconstruction in 16 cases colposuspension was also done to create a normal vesicourethral angle. All patients underwent clinical and urodynamic evaluation at least 1.25 years after surgery (mean followup 5.59). Patients who were too young for the clinical assessment of continence by January 1999 were excluded from study. RESULTS: All patients are continent. A secondary endoscopic procedure was required in 13 cases, including cystoscopy only in 2, scar incision near the ureteral orifice in 3, endoscopic reflux treatment in 4, ureterocele remnant resection in 2 and bladder neck incision for obstructive voiding in 2. Secondary open bladder reconstruction was performed in another case due to a diverticulum. Postoperatively only 1 or 2 uncomplicated episodes of urinary tract infection developed in 11 patients, while there were recurrent urinary tract infections in 4. In a patient with a preexisting loss of renal function a severe infection led to renal scarring. The voiding pattern was normal in 29 patients but 11 had dysfunctional voiding, including 5 with recurrent urinary tract infection. Urodynamic followup confirmed these clinical findings. Bladder capacity in these patients was relatively high at an average of 124% of expected capacity for age. We noted no statistically significant difference in followup parameters in patients who underwent surgery before and after age 1 year. Additional colposuspension in 16 patients did not result in any significant change in outcome compared with that in patients without this procedure. CONCLUSIONS: When compared with results in the literature, complete primary lower urinary tract reconstruction in patients with ectopic ureterocele appears to have better results than a staged approach with initial endoscopic treatment. Moreover, our study provides no proof that extensive reconstructive bladder surgery in neonates and infants leads to bladder function deterioration at a later age.     

Magnetic resonance urography in children: evaluation of suspected ureteral ectopia in duplex systems.

PURPOSE: We evaluate the diagnostic accuracy of magnetic resonance urography in children with suspected ectopic ureters and ureteroceles in duplex systems. MATERIALS AND METHODS: A total of 14 children 4 weeks to 8 years old with a total of 18 duplex systems underwent magnetic resonance urography using a 1.5 tesla scanner. After injection of low dose furosemide, half-Fourier rapid acquisition with relaxation enhancement images were obtained for T2-weighted static fluid magnetic resonance urography. Respiratory gated 3-dimensional gradient echo images were acquired for T1-weighted excretory magnetic resonance urography 5 to 30 minutes after intravenously administered gadolinium. RESULTS: All magnetic resonance examinations were successfully performed without sedation. The diagnostic accuracy of T1-weighted excretory magnetic resonance urography depended on the renal function. Twelve duplex systems with a normal excretory function, including 6 bifid ureters and 6 upper moieties with inferomedial ectopic ureters, were analyzed correctly with the exception of a 6 mm. ureterocele in 1 case. In 6 duplex systems with poor or nonfunctioning upper moieties ectopic ureters were only demonstrated on T2-weighted magnetic resonance urograms. CONCLUSIONS: Respiratory gated excretory and static fluid magnetic resonance urography complement each other in the evaluation of duplex systems in children and provide high accuracy in the evaluation of suspected ectopic ureters and ureteroceles.     

Single-system ectopic ureters: a review of 12 cases.

Eight boys and 4 girls with single-system ectopic ureters were seen during a 15-year period. The abnormality was bilateral in 4 patients and the majority had major associated urological and other abnormalities. Eight ectopic ureters were reimplanted successfully into the bladder and 4 nonfunctioning kidneys were removed, as were 2 "blind" ectopic ureters. One patient died during the neonatal period and the others have been followed from 1 to 15 years. Renal function was noted to be normal in 10 patients and 1 has mild renal failure. Bladder function was normal in 8 patients. Early surgery should be undertaken in patients with single-system ectopic ureters. Stabilization of the upper urinary tract can be anticipated and satisfactory bladder function can also be expected in the majority of cases.     

Diagnosis of bladder carcinoma using protoporphyrin IX fluorescence induced by 5-aminolaevulinic acid

OBJECTIVE: To report the results of a clinical study investigating the diagnosis of malignant and dysplastic bladder lesions by protoporphyrin IX (PPIX) fluorescence and to compare them with those from earlier studies. PATIENTS AND METHODS: The study included 55 patients with suspected bladder carcinoma (at initial diagnosis or at tumour follow-up visits); 130 bladder biopsies from 49 patients were classified by pathological analysis. All patients received an intravesical instillation of 50 mL of a 3% 5-aminolaevulinic acid (ALA) solution a mean of 135 min before cystoscopy, which was then performed under white and blue light. Malignant/dysplastic lesions showing red fluorescence under blue-light excitation were noted and the increase in detection rate calculated. RESULTS: There were 63 benign and 67 malignant/dysplastic areas biopsied; 10 malignant/dysplastic lesions (four transitional cell carcinoma, two carcinoma in situ, four dysplasia) were not detected during routine white-light cystoscopy but were identified under blue light. Fluorescence cystoscopy improved the overall diagnosis of malignant/dysplastic bladder lesions by 18% over standard white-light cystoscopy. The improvement was greater for dysplastic lesions and carcinoma in situ (50%). However, the improvement over standard cystoscopy was less than that found by other groups. CONCLUSION: The ALA-based fluorescence detection system significantly enhanced the diagnosis of malignant/dysplastic bladder lesions. However, determining the optimum drug exposure time requires further investigation using well-characterized instrumentation and study protocols, which would then allow comparison of the results from different groups.     

Single-system ectopic ureters. A review of 19 cases

Single system ectopic ureters are usually associated with multiple congenital abnormalities and the corresponding renal units is frequently abnormal. 19 cases of single system ectopic ureters were diagnosed and treated in our hospital during the last 20 years. The patients were less than 11 years old. The abnormality was bilateral in two cases and the 63% of all had associated malformations, being the anorectal abnormalities the most frequent. The incidence of reflux into the ectopic ureter was 57%, and the association to unilateral or contralateral renal agenesis, 26.3%. Thirteen ectopic ureters were reimplanted successfully into the bladder, and the cases of nonfunctioning kidneys were removed (nephroureterectomy). The follow-up period was 10 months to 14 years, developing the 68% of the cases without any complication and a good renal function. Two patients were transplanted due to a kidney failure. Diagnosis is often extremely difficult and requires a high degree of suspicion. This diagnosis may be incidental, and it may be made during investigation of patients with other malformations. An early diagnosis and treatment must be made in order to avoid a disturbance of renal function. We wish to point up the high incidence of reflux into the ectopic ureter and the high association to renal agenesis in the single system ectopic ureters in comparison with ectopic ureter of duplex system.     

Single ectopic ureter in the male

Three male patients with single eetopic ureters, opening into the ejaculatory duct, seminal vesicle, or prostatic urethra, are presented; in each the associated kidney was dysplastic. This diagnosis should be considered when a male patient presents with recurrent urinary tract infections, epididymitis, painful defecation, or vague, lower abdominal pain, associated with radiographic findings of a nonvisualized kidney and an extrinsic bladder defect. The surgical procedure of choice is nephroureterectomy, with excision of the structure receiving the ectopic ureter.     

Laparoscopy for definite localization and simultaneous treatment of ectopic ureter draining a dysplastic kidney in children

BACKGROUND AND PURPOSE: Single-system ectopic ureter draining a dysplastic kidney is a rare urologic abnormality. In this study, we evaluated our own experience using laparoscopy for the simultaneous identification and removal of such ureterorenal units. PATIENTS AND METHODS: Between February 1999 and August 2001, four girls with a mean age of 11 years presented with urinary incontinence. After imaging studies including CT scan, MRI, or both were done, all the patients underwent laparoscopy for definitive localization and simultaneous treatment. RESULTS: In all cases, ultrasonography and intravenous urography combined to reveal a single normal kidney. Even the CT scan could not identify the dysplastic kidney or ectopic ureter in three children. Laparoscopy was performed transperitoneally in all four patients, and a small dysplastic kidney was identified. Discovery of the kidney was not difficult because we initially identified the ureter crossing over the iliac vessels. Laparoscopic nephroureterectomy was successful in all patients with a mean operative time of 102 minutes. There was no significant intraoperative or postoperative complication, and the mean postoperative hospital stay was 2.5 days. All patients have remained completely dry without any problems after surgery. CONCLUSIONS: For patients having a clinical suspicion of ectopic ureter draining a dysplastic kidney, laparoscopy may represent an alternative modality for simultaneous diagnosis and treatment.     

ECTOPIC URETER OPENING INTO THE SEMINAL VESICLE IN AN INFANT: A CASE REPORT AND REVIEW OF THE JAPANESE LITERATURE

A case is presented of an ectopic ureter opening into the seminal vesicle associated with hypodysplastic kidney In an infant. We reviewed 135 cases (139 ureteral units) of male ectopic ureter from the Japanese literature and, of the 139 ectopic ureters, 109 were single-system ectopic ureters, and 26 ureters were associated with the ureteral duplication. Sixty-three and 73 ureters opened into the urinary tract and seminal tract. respectively. In patients 15 years or older, 65 cases of ectopic ureter opened into the seminal tract and 33 cases opened into the urinary tract, whereas in children under 15 years, the ectopic orifice was located more often in the urinary tract (26 cases) than in the seminal tract (8 cases). Presenting symptoms differed according to the location of the ectopic orifice. Ectopic ureters opening into the urinary tract most often presented with urinary tract infection and abdominal or lumbar pain. On the other hand, voiding and ejaculatory symptoms as well as perineal or genital pain were characteristic in ectopic ureters opening into the seminal tract. Of the 83 associated renal segments that were surgically removed, dysplasia. hypoplasia and aplasia were found in 24. 14 cases, respectively. It was noteworthy that 48 of the 53 single ectopic ureters opening into the seminal vesicle were associated with ipsilateral renal dysgenesis.     

Congenital mid ureteral strictures

PURPOSE: Congenital mid ureteral stricture is rare. We report 7 cases, and discuss the differences in preoperative evaluation and surgical management compared to other obstructive entities. MATERIALS AND METHODS: Medical records and imaging studies of 7 children identified with mid ureteral strictures between 1998 and 2002 were reviewed retrospectively. Five newborns presented with prenatal hydronephrosis, and 2 children presented at age 15 years, one in the course of evaluation of blunt trauma, and one due to pain and abdominal mass. Imaging studies included renal ultrasound, voiding cystourethrography, radionuclide renography and computerized tomography. All patients underwent retrograde pyelography. Pathological examination of each specimen was undertaken at the respective institutions. RESULTS: Prenatal hydronephrosis was the most common presentation. There were no urinary tract infections. All patients had significant obstruction on the affected side. No patient had vesicoureteral reflux. After imaging but before surgery the urinary obstruction was believed to be at the ureteropelvic junction in 4 patients and the ureterovesical junction in 2, and secondary to posterior urethral valves in 1. At cystoscopy all of the affected ureters had a normally located and normally configured orifice. Retrograde pyelography led to an accurate diagnosis of mid ureteral narrowing in all patients. Six patients underwent ureteroureterostomy, all of whom had satisfactory outcomes. In 1 of these patients contralateral nephrectomy was performed due to nonfunction of the multicystic dysplastic kidney. The remaining patient underwent nephrectomy for ipsilateral end stage kidney disease and hydronephrosis. In this patient the ureters were stenotic and suggested asymmetry in the thickness of the muscular coat, perhaps secondary to extrinsic compression. CONCLUSIONS: Congenital mid ureteral stricture is rare. Renal ultrasound and radionuclide renography alone do not reliably demonstrate the site of obstruction. Retrograde pyelography at the time of surgical correction of presumed ureteral obstruction is an important adjunct for correctly identifying the site of narrowing in the affected ureteral segment, unless the ureter has been imaged with another modality.     

Ectopic ureterocele: a case report

A case of ectopic ureterocele is reported. A 2-year-old girl was admitted for recurrent episode of urinary tract infection associated with fever. IVP showed bilateral duplex kidney, although no excretion of dye was noted from the right upper kidney. IVP also revealed a large filling defect at the bladder neck which was diagnosed as ureterocele by cystoscopy. Cystography demonstrated VUR to the right lower kidney. A complete duplication of ureter with ectopic ureterocele on the right, and incomplete duplication of ureter on the left were found at operation. She underwent complete removal of the ectopic ureterocele and reimplantation of the right two ureters. Her postoperative course was uneventful, post-operative IVP revealed improvement of pyelography of the right lower kidney and cystography revealed no VUR.     

Long-term chronic complications from Stamey endoscopic bladder neck suspension: a case series

Purpose/objective Long-term complications from anti-incontinence surgical procedures are rarely reported. We report on delayed presentation of complications relating to the synthetic bolster placed for the Stamey bladder neck suspension. Materials and methods: Patients undergoing re-operative surgery following prior Stamey endoscopic bladder neck suspension were selected from a surgical database. Four women with lower urinary tract and/or vaginal symptoms following prior Stamey endoscopic bladder neck suspension were identified. All patients had undergone removal of the bolster material by a single surgeon (ESR) at re-operation. Preoperative, operative, and postoperative inpatient and outpatient records were reviewed. Results: Patients presented with a variety of symptoms including urinary incontinence, recurrent cystitis, vaginitis, and urinary frequency at 9, 11, 11, and 12 years after Stamey bladder neck suspension. In addition, two patients presented with recurrent, intermittent bloody vaginal discharge and two patients complained of recurrent urinary tract infections and irritative voiding symptoms. All patients underwent transvaginal excision of the Dacron bolster. Three patients also underwent placement of an autologous pubovaginal sling for symptomatic recurrent stress urinary incontinence. At a mean follow-up of 30 months all four patients were improved. There was no recurrence of vaginal discharge or urinary tract infections. Irritative voiding symptoms resolved. Conclusions: Delayed complications from surgically implanted synthetic materials can present many years after initial implantation. The clinical findings are often subtle and require a high degree of suspicion. Vaginal discharge and irritative urinary symptoms in patients with even a remote history of Stamey bladder neck suspension should prompt a thorough vaginal exam and cystoscopy. Excision of the bolsters can be performed and is usually followed by symptomatic improvement.     

Retention cyst of the prostate in a patient with urinary difficulty

A 54-year-old man visited our clinic for dysuria. Transabdominal ultrasonography revealed a multilocular cyst at the neck of the bladder, and a cystoscopy revealed obstruction of the neck of the bladder. Dysuria improved after tamsulosin treatment was initiated, and abdominal magnetic resonance imaging (MRI) showed disappearance of the cyst. The patient had urinary difficulty again after 2 years. An MRI and cystoscopy revealed recurrence of the cyst. Tamsulosin administration was reinitiated, but his urinary difficulty did not improve. Transurethral resection of the cystic wall was performed. Histopathological examination indicated a retention cyst.     

Analysis of solid renal dysplasia by flow cytometry: malignant potential?

Renal nodular blastema/nephroblastomatosis is a recognized precursor of Wilms tumor. It also has been shown that nodular renal blastemata are seen in association with dysplastic renal parenchyma secondary to obstructive uropathy (i.e., ureteroceles or ectopic ureters). In an attempt to improve our understanding of the critical relationship between renal dysplasia and neoplasia, we performed flow cytometric evaluation on 16 paraffinembedded specimens of dysplastic kidneys removed during the period 1984–1989. All nephrectomy specimens were associated with obstruction, either duplex collecting systems (10), ectopic ureters (2) or posterior urethral valves (2), or vesicoureteral reflux (2). One specimen was found to contain nodular renal blastema. No evidence of malignancy was found in any specimen. A specimen of normal kidney and two of Wilms tumor (favorable histology) were studied for comparison. Nuclear deoxyribonucleic acid (DNA) ploidy studies were performed on single dissociated nuclei after deparaffinization and staining with propidium iodide. All dysplastic specimens, including the specimen with nodular renal blastema, demonstrated a diploid pattern of DNA as did the specimens of normal renal tissue. The Wilms tumor specimens demonstrated a diploid and a tetraploid pattern. In view of the fact that Wilms tumor may demonstrate diploid DNA patterns on flow cytometry, the findings of diploid patterns on all specimens of solid dysplasia militate against but do not eliminate the possibility of malignant degeneration.     

Bladder urothelial cell carcinoma as a rare cause of haematuria in children: Our experience and review of current literature

ObjectivesTo report our experience of bladder urothelial cell carcinoma (UCC) in children and review contemporary management and follow-up of paediatric UCC.Patients and methodsBetween 2004 and 2020, five patients (4 boys and 1 girl) were managed at our centre for urothelial cell carcinoma of the bladder. Data was collected by note review for age at presentation, symptoms, clinical findings, investigations, treatment and follow-up.ResultsAll five patients presented with visible haematuria, two had dysuria and one had suprapubic pain. Bladder ultrasound scan (USS) showed exophytic bladder lesions in only 4 patients. Definitive diagnosis and treatment were achieved by cystoscopic excision. Four patients had PUNLMP while one had Grade 3 pTa UCC of the bladder which required further cystoscopic excision and intravesical Mitomycin C (MMC) instillation. All patients were followed up clinically, with renal USS and cystoscopy. We have observed recurrence of the carcinoma in two patients requiring further cystoscopic excision and intravesical MMC.ConclusionBladder urothelial cell carcinoma in children should be suspected in children presenting with haematuria. If renal USS is normal, cystoscopy should be considered for diagnosis and treatment. Compared to adults, children with bladder UCC often have favourable histopathology and prognosis. Close follow-up is necessary with renal USS and cystoscopy to detect recurrence even in PUNLMP.     

Magnetic resonance urography: a new gold standard for the evaluation of solitary kidneys and renal buds?

PURPOSE: We evaluated the diagnostic potential of magnetic resonance urography (MRU) in pediatric patients with a solitary kidney and/or dysplastic orthotopic or ectopic renal buds. We present our evolving experience with this imaging procedure. MATERIALS AND METHODS: A total of 30 patients with a mean age of 43.8 months with a known or suspected solitary kidney with or without clinical symptoms underwent ultrasound of the urinary tract as well as voiding cystourethrogram, renal static dimercapto-succinic acid (DMSA) scintigraphy and MRU. The results of these diagnostic imaging studies were then compared with each other and set against the results of the final diagnosis established at surgery and by histology, if available. RESULTS: Dysplastic orthotopic or dystopic renal buds suspected on ultrasound in 11 of the 30 patients were confirmed in all 11 by MRU. While accompanying ectopic ureteral insertions were shown in only 3 patients by ultrasound, they were visualized in all 4 by MRU. The other 7 patients with dysplastic renal buds had orthotopic ureteral orifices. DMSA scintigraphy failed to detect 10 renal buds. CONCLUSIONS: The diagnostic value of MRU appears to be superior to that of other imaging tests, even to that of DMSA scintigraphy, which with voiding cystourethrography is currently considered the gold standard for evaluating sonographically suspected solitary kidneys with contralateral orthotopic or ectopic renal buds and ectopic ureteral insertion.