Obstrução do Trato Urinário Baixo Fetal / Fetal lower urinary tract obstruction

A obstrução do trato urinário baixo fetal (fetal lower urinary tract obstruction - LUTO) é uma patologia caracterizada por dilatação da bexiga e hidronefrose bilateral causada por obstrução do trato urinário inferior. Sua incidência é de 2,2 em cada 10.000 nascimentos. A etiologia da LUTO inclui a válvula da uretra posterior (VUP), atresia ou estenose uretral. O diagnóstico é feito por ultrassom, que mostra bexiga dilatada, com paredes espessas (megabexiga), e uretra posterior aumentada. O tratamento cirúrgico clássico (derivação vésico-amniótica guiada por ultrassom) estaria indicado quando o líquido amniótico normal começa a diminuir, com aumento da distensão vesical e da hidronefrose. O tratamento inclui a colocação de derivação vésico-amniótica guiado pelo ultrassom e fetoscópica com coagulação a laser. De acordo com a gravidade, a LUTO é classificada nos estágios 1,2 e 3.(AU)

The Fetal Lower Urinary Tract Obstruction (LUTO) is a spectrum of diseases characterized by bladder distension and bilateral hydronephrosis in consequence of the LUTO. The incidence is approximately 2.2 in 10,000 births and it is commonly diagnosed during the late first or early second trimester of pregnancy. The etiologies of LUTO include posterior urethral valves, urethral atresia and urethral stenosis. Complete bladder outlet obstruction (severe LUTO) is associated with high perinatal mortality due to pulmonary hypoplasia and severe renal impairment/damage. The prenatal intervention includes vesicoamniotic shunt placement guided by ultrasound and fetoscopic laser coagulation. It is suggested that LUTO patients could be categorized in three stages according to disease gravity: Stages 1, 2 and 3.(AU)

Evaluation of renal transit time [RTT] in children with MR urography

To evaluate use of dynamic contrast material-enhanced.magnetic resonance [MR] urdgraphy for measurement, of renal transit time [RTT of a contrast agent through the kidney and collecting system so as to identify obstructive uropathy in children. One hundred twenty-six children suspected of having hydronephrosis were hydrated prior to undergoing both conventional and dynamic contrast-enhanced MR urography of the kidneys and urinary tract. A three-dimensional sequence was used to track passage of contrast agent through the kidneys. Time between the appearance of contrast material in the kidney and its appearance in the ureter at or below the level of the lower pole of the kidney was defined as RTT. Bland-Altman plots were used to quantify intra- and interobserver performance. In 30 children, a nuclear medicine renogram was also obtained, and the half-life of renal signal decay after furosemide administration was derived and compared with the MR imaging RTT by using receiver operating characteristic curves. On the basis of RTT, kidneys were classified as normal [RTT RTT 490 seconds]. Receiver operating characteristic analysis for comparison of results of MR imaging and diuretic renal scintigraphy showed.good agreement between the modalities, with a mean area under the curve of 0.90. When used in conjunction with morphologic images obtained in the same, examination, RTT generally allowed normal kidneys to be differentiated from obstructed and partially obstructed kidneys

Congenital urethral anomalies in boys. Part II

In the second part of this article, congenital urethral anomalies other than posterior urethral valve were reviewed. The anomalies considered in the current review were anterior urethral valve, lacuna magna, syringocele, Cobb's collar, duplication of urethra, megalourethra, and prostatic urethral polyps. The literature was extensively reviewed concerning the presentations, diagnosis, different types of treatment modalities, morbidity, mortality, and new concepts for the above disorders. Anterior urethral valves or diverticula are the most prevalent congenital anomalies of anterior urethra. The lacuna magna is the largest depression in the dorsal aspect of the fossa navicularis. It is demonstrable on a well-performed voiding cystourethrography of the distal urethra. The dilated Cowper's gland duct is the other missed diagnosed anomaly of the urethra in boys. The congenital narrowing of the bulbar urethra with a variable clinical presentation and obstruction grade and different types of anterior urethral obstruction are the most common presentation of these anomalies. However, other symptoms or signs including, hematuria, bloody spotting on underwear, discomfort or sever pain in the vicinity of the glance, interrupted voiding, infection, bulging of anterior urethra, enuresis, and postvoiding dribbling are the only nonspecific manifestations of these disorders. All of these disorders are demonstrable on a well-performed voiding cystourethrography of the distal urethra. The urologist must be aware about these uncommon congenital anomalies and the anterior urethra should be carefully evaluated for such anomalies. Diagnosis of these entities is elusive unless the physician is looking for them. Nonspecific symptoms mentioned here besides radiographic findings can be a valuable clue for diagnosis

Ultrasonography in obstructive uropathy in infants

The study included 18 male patients aged 2mg. to 2 years, presented by vomiting, dehydration, abdominal distention, oliguria or even anuria. Rehydration by I.V. fluids and symptomatic treatment of vomiting and abdominal distension have improved the general condition of the patients but not the urine outflow. Blood urea and serum creatinine were elevated. Plain X-ray on the abdomen and IVU were done for all patients but were inconclusive. Abdominal ultrasonography revealed bilateral pelviureteric obstruction by radiolucent stones in 8 cases, bilateral ureteric dilatation without evident cause of obstruction in 2 cases, bladder outflow obstruction due to posterior uretheral valve in 6 cases and bladder neck obstruction in 2 cases Blood urea, serum creatinine and dilatation of the collecting system returned to normal within 4-10 days and 10-15 days respectively in 10 cases. While in8 cases improvement of such parameters occurred but not return to normal. Reduction of the thickness of renal cortex as well as focal increase in renal cortical echogenicity due to renal scarring was observed in this later group of patients by follow-up abdominal ultrasonography