Urethra valve

Fig. 1.1.6. VCU in a 7-year-old boy who complained of dys-uria. Oblique view during micturition. Slightly irregular bladder cannot be interpreted as abnormal during micturition. Bladder diverticulum (the same was shown on the opposite side). Moderate dilatation of the posterior urethra. Valves were suspected. Cystoscopy confirmed the diagnosis, and coagulation was performed. However, the orifices of the diverticula were not seen by the surgeon...

Fig. 6.3. Suprapubic voiding cystourethrography in a neonate with posterior urethral valves. A high-capacity heavily trabeculated bladder was opacified. Distended posterior urethra. Valves are ballooned by contrast medium ( sail in the wind sign)...

However, in the last decade the main application of bacterial cellulose has been in the biomedical materials field [13,46,55-57], Due to its unique nanostructure and properties, microbial cellulose is a nattnal candidate for numerous medical and tissue-engineered apphcations. In fact, much work has already been focused on designing ideal biomedical devices from BNC, such as artificial skin, blood vessels, cornea, urethra, bone, cartilage, porcine knee menisci, and heart valve prosthesis as well as deliveries of drug, hormone and protein [58-62], Figure 2,5 illustrates some of the prospects for the various biomedical applications of BNC-based materials. 

When the shape is abnormal or the bladder is empty, capacity should not be inferred from US measures (Bis and Slovis 1990). The transperineal approach can be useful to visualize dilated posterior urethra in boys with valves (Teele and Share 1997). Finally, ureteral jets into the bladder can be detected with color Doppler (Leung et al 2007). 

Kaufmann-McKusick syndrome Hydrometrocolpos, transverse vaginal membrane, vaginal septum, postaxial polydactyly, cardiac anomalies, hypospadias Hydroureter, ureteral duplication, ectopic urethra, urogenital sinus, posterior urethral valves AR (236700), mutations in Bardet-Biedl type 6 BBS6 gene... 

Posterior urethral valves consist of abnormal mucosal folds between the urethral wall and the distal end of the verumontanum. The classification established by Young at the beginning of the twentieth century appears questionable from an endoscopic perspective (Dewan et al. 1992). Young had identified three types of valves. Type I was described as a bicuspid valve radiating distally from the posterior edge of the verumontanum to the anterior aspect of the proximal membranous urethra. Type 1 valves are by... 

The same day, VCU is performed commonly after suprapubic puncture (Fig. 6.3). Aspiration of stagnant urine is performed via a vesical catheter that can be left in place thereafter. All precautions must be taken to ensure sterility given the increased risk of post-procedural infection. Infection could be life threatening for the baby and devastating for renal function. Retrograde opacification would be technically possible since valves produce only one-way obstruction. However, it can be difficult to pass through the bladder neck due to the dilated posterior urethra, which can retain the tip of the tube. 

Fig. 6.7. a VCU in a 7-year-old boy with dysuria, showing extrinsic compression of the urethra due to abnormal sphincter contraction during micturition. This functional anomaly should not be mistaken for posterior urethral valves. Urody-namic studies favor dysfunctional voiding with bladder-sphincter dyscoordination during voiding. Biofeedback physiotherapy was carried out. Clinical outcome was favorable, b Follow-up VCU shows normalization of urethral anatomy during... 

The commonest congenital abnormality of the urethra is posterior urethral valves, which may result in the most severe renal disease in childhood (see also Sect. 6.2). This condition requires regular followup with imaging. Antenatal insertion of a double-J stent between the fetal bladder or dilated collecting system of the kidneys and the amniotic cavity under sonographic guidance allows decompression of the urinary tract. However, as this procedure... 

Fig. 18.12. a Infant with posterior urethral valves. There is dilatation of the posterior urethra (arrow) and marked reflux, b Patient developed echogenic area in the lower pole collecting system after valve surgery (curved arrow), c Stone developed at site of Candida ball 1 month after surgery (open arrowhead)... 

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