It occurs in approximately 1 in every 1500 live births, is most commonly seen in males, involves the left ureter twice as often as the right ureter. UPJ obstruction is transient in most cases. Lower urinary tract obstruction
Lower urinary tract obstruction involves the lower ureters, urinary bladder and the urethra. Ureterovesicular junction obstruction
Ureterovesicular junction obstruction (UVJ obstruction) is an obstruction at the level of the ureter and bladder. It accounts for 20% of cases of hydronephrosis detected in utero. It is also most commonly seen in males and involved both sides of the urinary tract in approximately 25% of cases. Posterior urethral valves
Posterior urethral valves (PUV) is an obstruction at the level of the urethra. It occurs in approximately 1 in every 5000 to 8000 live births and only occurs in males. Since PUV always affects both sides of the urinary tract, patients with posterior urethral valves are at the greatest risk for developing chronic kidney disease and end-stage renal disease due to obstructive uropathy. Ureterocele
A ureterocele is a cystic dilation of the end of the ureter that can occur in the bladder and/or in the urethra. It occurs in approximately 1 in every 5000 live births, is most commonly seen in females and involves both ides of the urinary tract in approximately half of cases. Urethral stenosis
Urethral stenosis is a narrowing of the urethra that prevents urine from exiting the bladder. Diagnosis
Prenatal diagnosis
Bladder outlet obstruction can be identified during routine prenatal ultrasonography as dilation of the fetal urinary tract and decreased amniotic fluid levels.
Phonotrauma subjects the vocal folds to excessive mechanical forces during these vibratory cycles, which can lead to the development of a wound. It is the healing of these wounds, which leads to tissue re-structuring, that can result in a vocal fold cyst. Diagnosis
There are generally four components included in the full diagnosis of a vocal cord cyst: a medical and voice history, a head and neck exam, a perceptual assessment of the voice and imaging of the vocal folds. A medical and voice history can help distinguish patterns of misuse and phonotrauma to assist in diagnosis. The primary perceptual sign of vocal fold cysts is hoarseness of the voice. Diagnosis through perceptual means alone is difficult, therefore in the fourth component of diagnosis the patient often undergoes an imaging procedure. Imaging is most commonly done with laryngeal videostroboscopy. A videostroboscopy is an examination of the vocal folds using flashes of light to slow down the image of the vocal fold movement enough to provide a sharp picture of the phases of the movement cycle (mucosal wave.) This procedure provides information about vocal fold vibrations during speech, vocal intensity and vocal frequency. Imaging shows the reduced movement of the vocal folds (mucosal wave) when a vocal fold cyst is present. Further, videostroboscopy tends to show increased submucosal swelling in the affected areas of the vocal fold(s) More recently, other technologies have been introduced to assist with obtaining imaging of the vocal folds, including the use of Narrow-band imaging (NBI.)