Bulbar urethra

The bulbar urethra is surrounded by the bulb of the corpus spongiosum it is larger than the other portions (1.5-2 cm), does not have stiff fascia and extends from the perineal area to the suspensor ligament of the penis. 

Fig. 19.3a,b. Sonourethrography. Normal appearance of the urethra in sagittal (a) and transversal (b) scans. The urethra distended hy the saline solution appears as an anechoic tubular structure well depicted with linear array transducer using direct skin contact on the ventral surface of the penis and with trans-scrotal and perineal scanning for bulbar urethra... 

The bulbar urethra can be studied by placing the probe on the ventral surface or transperineally after having lifted the scrotum. The most useful scans are... 

Fig. 21.11. Sagittal scan obtained after SonoVue microbubble administration showing a stenosis of the bulbar urethra (arrowhead)...

Cobb s collar (Cobb et al. 1968) is a congenital narrowing of the bulbar urethra with no connection to the verumontanum (Dewan et al. 1994). It was shown that Cobb s collar is frequently associated with tubular or cystic dilatation of Cowper s glands ducts (also called syringocele) (Dewan 1996), both structures arising embryologically from the urogenital membrane area. 

Careful attention must always be given to precise assessment of the urethral morphology in order to detect narrowing of the bulbar urethra (Cobb s collar) (Dewan et al. 1995 Nonomura et al. 1999) and congenital obstructing posterior urethral membranes (COPUM) (Dewan 1993 Dewan et al. 1997). 

No6 HN (1988) The relationship of sibling reflux to index patient dysfunctional voiding. J Urol 130 1138-1141 Nonomura K, Kanno T, Kakizaki H et al (1999) Impact of congenital narrowing of the bulbar urethra (Cobb s collar) and its transurethral incision in children. Eur Urol 36 144-149... 

Many small glands (of Littr ) are to be found at the lumen of the anterior urethra, which are more numerous in the bulbar portion and near the fossa navicularis. 

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