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Congenital Megaureter

Congenital Dilatation of Ureter

A congenital megaureter is an anomaly of the urinary tract characterized by an abnormally dilated ureter, usually accompanied by renal pelvis dilation. A substantial number of patients are asymptomatic, whereas the development of urinary tract infections, together with hematuria, fever, and abdominal pain are main findings in symptomatic cases. The diagnosis can be made through imaging studies, with grey-scale ultrasonography, voiding cystourethrography, and intravenous urography serving as the procedures of choice.


Presentation

Congenital anomalies of the urinary tract are considered to be rather common in the general population, with an incidence of 1 in 500 individuals [1]. A congenital megaureter, an important cause of obstructive uropathy in the neonatal and pediatric population [3], is defined as abnormal dilation of the ureter, together with dilation of the renal pelvis in most cases [1]. Several types have been described in the literature - obstructed or nonobstructed and refluxing or nonrefluxing [1] [2] [3]. The clinical presentation of a congenital ureter is often asymptomatic and the majority of patients are incidentally diagnosed on prenatal ultrasonography [3]. When the congenital megaureter is not visualized during this period, recognition might be delayed until adulthood due to the absence of complaints [3] [4]. Symptomatic cases, on the other hand, may manifest as more frequent urinary tract infections (UTIs), recurrent urolithiasis, nonspecific abdominal pain, and fever [3] [4]. Hematuria (both microscopic, and in the presence of calculi, macroscopic) can also be a part of the clinical presentation [3]. Renal failure is rarely seen due to congenital megaureter, but renal dysplasia and hydronephrosis are reported as more severe complications [3] [5].

Abdominal Pain
  • Symptomatic cases, on the other hand, may manifest as more frequent urinary tract infections (UTIs), recurrent urolithiasis, nonspecific abdominal pain, and fever.[symptoma.com]
  • Most patients present with nonspecific symptoms, including dull abdominal pain, of less than 12 months' duration but patients can present with the complications of the fibrosis.[patient.info]
Abdominal Pain
  • Symptomatic cases, on the other hand, may manifest as more frequent urinary tract infections (UTIs), recurrent urolithiasis, nonspecific abdominal pain, and fever.[symptoma.com]
  • Most patients present with nonspecific symptoms, including dull abdominal pain, of less than 12 months' duration but patients can present with the complications of the fibrosis.[patient.info]
Excitement
  • The modifications in the axonal structure and those of the myelin sheath determine modifications of the nervous excitability and conductibility.[ncbi.nlm.nih.gov]
Ureteral Disorder
  • Ureteral Disorders Your kidneys make urine by filtering wastes and extra water from your blood. The urine travels from the kidneys to the bladder in two thin tubes called ureters. The ureters are about 8 to 10 inches long.[icdlist.com]
Bladder Spasm
  • Extravesical reimplantation has been shown to decrease postoperative hematuria, minimize bladder spasms, reduce the need for urethral catheter, and shorten hospital stay.[emedicine.medscape.com]
Sexual Dysfunction
  • His clinical interest is in Voiding and Sexual Dysfunction, urinary incontinence, neurogenic bladder, BPH, robotic surgery, and prostate cancer.[books.google.com]
Bladder Neck Obstruction
  • Bladder neck obstruction. Congenital urethral valves. Pinhole meatus. Neurogenic bladder. Functional failure due to denervation (eg, following spinal trauma, multiple sclerosis).[patient.info]

Workup

Imaging studies are the cornerstone for recognizing a congenital megaureter, but the role of the physician in raising clinical suspicion through a detailed physical examination and history taking is essential in order to make a presumptive diagnosis [5]. Signs and symptoms (if present) should be assessed during the interview with the patient (although the young age of the patient often necessitates collection of information from the parent) and during the physical exam, after which several procedures can be employed. Grey-scale ultrasonography (US), being noninvasive and readily used both in the prenatal and postnatal setting, is widely described as the optimal method for detecting a congenital megaureter [3] [5]. In addition, several other methods are recommended [3] [4] [5] [6]:

  • Voiding cystourethrography (VCUG) - Often used after the initial diagnosis is made by US, VCUG is an important tool for excluding ureteral reflux and possibly obstruction [2] [3].
  • Intravenous urography (IVU) and radioisotope renography - The insufficient quality of images obtained due to the immature anatomical landmarks of newborns and infants makes this procedure of limited benefit in the first few weeks of life, which is why radioisotope renography is sometimes preferred for early assessment [2] [3].

In addition, magnetic resonance urography (MRU), intravenous pyelography (IVP) and X-ray urography, but also computed tomography (CT) have all been described as very good methods to confirm a congenital megaureter, dilation of the renal pelvis and urolithiasis [3] [5] [6].

Treatment

  • Ureterocele Treatment of the ureterocele is based upon relief of obstruction.[emedicine.medscape.com]
  • Treatment and prognosis Usually asymptomatic and requiring no treatment. If complications occur or the degree of obstruction is marked then, reimplantation following resection of the aganglionic segment may be performed.[radiopaedia.org]
  • Both pure laparoscopic and robot-assisted laparoscopic surgery using different anti-reflux ureter bladder anastomoses are safe and effective approaches in the minimally invasive treatment of congenital megaureter.[ncbi.nlm.nih.gov]
  • The two techniques can complement each other in disease diagnosis and provide more detailed information for preoperative treatment.[ncbi.nlm.nih.gov]

Prognosis

  • Treatment and prognosis Usually asymptomatic and requiring no treatment. If complications occur or the degree of obstruction is marked then, reimplantation following resection of the aganglionic segment may be performed.[radiopaedia.org]
  • Surgical intervention virtually is universal and factors bearing upon recoverability and prognosis have been analyzed.[ncbi.nlm.nih.gov]
  • Prognosis Prognosis is dependent on the cause, location, degree and duration of obstruction. Bad prognostic factors are longer duration and worse severity of obstruction, together with concomitant infection.[patient.info]

Etiology

  • Therapy usually entails tunnelled reimplantation to prevent reflux. megaureter A large ureter of any etiology, divided by some urologists into reflux megaureter, obstructed ureter and non-reflux or idiopathic megaureter meg·a·lo·u·re·ter, megaureter ([medical-dictionary.thefreedictionary.com]
  • Megaureters are treated differently based on their etiology.[urology.ucsf.edu]
  • Etiology To date, the pathogenesis of megacalyces remains unclear [3,12]. A congenital defect has been suggested but not proven [5]. One case was diagnosed by prenatal ultrasound and some cases have been reported in the newborn [13].[urotoday.com]

Epidemiology

  • Epidemiology Age Urinary tract obstruction occurs most commonly in the young and the old: In older men, this is a relatively common condition due to prostatic enlargement: Incidence of lower urinary tract symptoms (LUTs)/BPH averages 15 per 1,000 man-years[patient.info]
  • Epidemiology of chronic kidney disease in children. Pediatr Nephrol 2012;27(3):363–373. [ Links ] 2. Toka HR, Toka O, Hariri A, Nguyen HT. Congenital anomalies of kidney and urinary tract. Semin Nephrol 2010;30(4):374–386. [ Links ] 3.[scielo.mec.pt]
Sex distribution
Age distribution

Pathophysiology

  • Brenner/Rector remains the go-to resource for practicing and training nephrologists and internists who wish to master basic science, pathophysiology, and clinical best practices.[books.google.com]
  • The pathophysiology of congenital obstructive uropathy is poorly understood. There are very few experimental models of prenatal obstruction of the urinary tract, except in the fetal lamb or inbred rats.[pubfacts.com]
  • Clinical and pathophysiologic features of 150 ureters. Urology 12: 160–176 Google Scholar Pohl M, Mentzel HJ, Vogt S et al. (2012) Risk factors for renal insufficiency in children with urethral valves.[doi.org]

Prevention

  • Successful nonoperative management of VUR requires preventing renal damage from pyelonephritis and has involved the use of continuous antibiotic prophylaxis and treating bowel or bladder dysfunction.[emedicine.medscape.com]
  • Prevention & Risk Assessment Prevention & Risk Assessment What causes a megaureter? A megaureter that is not associated with other problems occurs during fetal development.[childrensnational.org]
  • Early diagnosis of urinary obstruction is vital to prevent further damage or to reverse renal impairment.[news-medical.net]
  • Definitive surgical treatment involves refashioning the lower end of the affected ureter so that a tunnelled reimplantation into the bladder can be done to prevent reflux.[en.wikipedia.org]
  • Therapy usually entails tunnelled reimplantation to prevent reflux. megaureter A large ureter of any etiology, divided by some urologists into reflux megaureter, obstructed ureter and non-reflux or idiopathic megaureter meg·a·lo·u·re·ter, megaureter ([medical-dictionary.thefreedictionary.com]

References

Article

  1. Vlad M, Ionescu N, Ispas AT, Ungureanu E, Stoica C. Morphological study of congenital megaureter. Morphological study of congenital megaureter. Rom J Morphol Embryol. 2007;48(4):381-390.
  2. Berrocal T, López-Pereira P, Arjonilla A, Gutiérrez J. Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features. Radiographics. 2002;22(5):1139-1164.
  3. Shokeir AA, Nijman RJ. Primary megaureter: current trends in diagnosis and treatment. BJU Int. 2000;86(7):861-868.
  4. Rosenblatt GS, Takesita K, Fuchs GJ. Urolithiasis in adults with congenital megaureter. Can Urol Assoc J. 2009;3(6):E77-E80.
  5. Yu M, Ma G, Ge Z, Lu R, Deng Y, Guo Y. Unilateral congenital giant megaureter with renal dysplasia compressing contralateral ureter and causing bilateral hydronephrosis: a case report and literature review. BMC Urol. 2016;16:7.
  6. Li TR, Du XK, Huo TL. Magnetic resonance urography and X-ray urography findings of congenital megaureter. Chin Med Sci J. 2011;26(2):103-108.

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Last updated: 2019-06-28 10:47