Urethra disruption

Hormone disruption refers to a chemical s ability to mimic or block the action of the body s own hormones, or its ability to interfere with normal hormone production or breakdown in some way. Chemicals that are able to disrupt sex and thyroid hormones have been particularly under the spotlight, but other hormones, such as those of the adrenal gland, may also be subject to disruption. The overall result appears to be damage to reproductive, immune, and nervous systems, and increases in birth defects, selected cancers, and learning disabilities. For the last three decades, there has been a disconcerting increase in the incidence of such human health disorders as breast cancer, testicular cancer, hypospadias (a birth defect where the urethra does not open at the end of the penis) and learning disabilities. 

Timms BG, Howdeshell KL, Barton L, et al. Estrogenic chemicals in plastic and oral contraceptives disrupt development of the fetal mouse prostate and urethra. PNAS 2005 102(19) 7014-19. 

Diagnosis of associated urethral injury can be problematic. The patient can report a difficulty voiding, or present with blood at the meatus. In this case diagnostic catheterization must be avoided because it may convert a minimal tear into a complete tear of the urethra. The diagnosis is confirmed by a retrograde urethography with extravasion of contrast material at the site of the disruption. 

In case of minimal disruption, immediate urethral catheterization can be tried by gentle maneuver. If the catheter placement is not simple, it is better to avoid further handling. Suprapubic catheter placement is performed, and the lesion is then repaired within 15 days from the injury. This delayed primary repair seems to be the best choice because it avoids the risk of immediate abdominal exploration. The urethra can be repaired by endoscopic realignment or by surgical tension-free anastomosis via a perineal approach using one of a variety of techniques. 

In cases of complete disruption of the posterior urethra, the first step treatment is suprapubic drainage. The Mitrofanoff principle (interposition of the appendix between the urinary bladder and the abdominal wall), has been occasionally applied in severely crushed patients to divert the urine (Freitas Filho et al. 2003). No consensus has been made regarding the surgical strategy (Onen et al. 2005). Either primary realignment over a urethral tube, immediate surgery or delayed repair can be performed. 

The radiologist should avoid any urethral catheterization when urethral disruption is suspected. Secondary repair is the rule for urethral injuries, so that a minimal imaging evaluation should be performed in emergency situations (Baskin and McAninch 1993). Retrograde opacification of the urethra by water-soluble iodinated contrast medium is the reference examination (Fig. 25.15). A Foley catheter with a balloon inflated in the fossa navicu-laris is used. CT cystography can be considered in cases of bladder neck disruption and/or pelvic bones fractures. 

The key questions to address by imaging are as follows is there any urethral leak (the absence of a leak cannot exclude hematoma or contusion) and is there any retrograde opadfication of the bladder (allowing the differential diagnosis between complete and partial disruption of the urethra) The followup of patients is of primary importance. The aim is to detect urethral stenosis or diverticulum. Again, prudent retrograde opacification is the optimal examination. 

Fig. 25.15. Complete disruption of the membranous urethra in an adolescent boy shown by retrograde urethrography (arrow). Note the inflated balloon of the Foley catheter in the fossa navicularis...

---