Meatal stenosis

Urethral meatal stenosis is a narrowing (stenosis) of the opening of the urethra at the external meatus /miːˈeɪtəs/, thus constricting the opening through which urine leaves the body from the urinary bladder.

Urethral meatal stenosis
Other namesUrethral stricture
SpecialtyUrology

Symptoms
  • Abnormal strength and direction of urinary stream
  • Visible narrow opening at the meatus in boys
  • Irritation, scarring or swelling of the meatus in boys
  • Discomfort with urination (dysuria and frequency)
  • Incontinence (day or night)
  • Bleeding (hematuria) at end of urination
  • Urinary tract infections - increased susceptibility due to stricture

Causes

The protection provided by the foreskin for the glans penis and meatus has been recognized since 1915. In the absence of the foreskin the meatus is exposed to mechanical and chemical irritation from ammoniacal diaper (nappie) that produces blister formation and ulceration of the urethral opening, which eventually gives rise to meatal stenosis (a narrowing of the opening).[1] Meatal stenosis may also be caused by ischemia resulting from damage to the frenular artery during circumcision.[1][2]

Risk factors

Frisch & Simonsen (2016) carried out a very large-scale study in Denmark, which compared the incidence of meatal stenosis in Muslim males (mostly circumcised) with the incidence of meatal stenosis in ethnic Danish males (mostly non-circumcised). The risk of meatal stenosis in circumcised males was found to be as much 3.7 times higher than in the non-circumcised males.[1]

Diagnosis

In boys, history and physical exam is adequate to make the diagnosis. In girls, VCUG (voiding cystourethrogram) is usually diagnostic. Other tests may include:

Prevention

In the newborn

According to Frisch & Simonsen (2016), "the foreskin is protective against urinary stricture disease" (meatal stenosis).[1] Frisch & Simonsen (2016) call for a "thorough reassessment of the burden of urethral troubles and other adverse outcomes after non-therapeutic circumcision of boys."[1]

Saeedi et al. (2017) propose long-term follow-up of circumcision with ultrasonography "to detect meatal stenosis before permanent renal damage occurs."[3]

After hypospadias repair

Meir & Livne (2004) suggest that use of a broad spectrum antibiotic after hypospadias repair will "probably reduce meatal stenosis [rates]",[4] while Jayanthi (2003) recommends the use of a modified Snodgrass hypospadias repair.[5]

Treatment

In females, meatal stenosis can usually be treated in the physician's office using local anesthesia to numb the area and dilating (widening) the urethral opening with special instruments.

In boys, it is treated by a second surgical procedure called meatotomy in which the meatus is crushed with a straight mosquito hemostat and then divided with fine-tipped scissors.[6] Recently, home-dilatation has been shown to be a successful treatment for most boys.[7]

Prognosis

Most people can expect normal urination after treatment.[6]

Incidence

Numerous studies over a long period of time clearly indicate that male circumcision contributes to the development of urethral stricture. Among circumcised males, reported incidence of meatal stricture varies. Griffiths et al. (1985) reported an incidence of 2.8 percent.[8] Sörensen & Sörensen (1988) reported 0 percent.[9] Cathcart et al. (2006) reported an incidence of 0.55 percent.[10] Yegane et al. (2006) reported an incidence of 0.9 percent.[11] Van Howe (2006) reported an incidence of 7.29 percent.[2] In Van Howe's study, all cases of meatal stenosis were among circumcised boys. Simforoosh et al. (2010) reported an incidence of 0.55 percent.[12] According to Emedicine (2016), the incidence of meatal stenosis runs from 9 to 20 percent.[6] Frisch & Simonsen (2016) placed the incidence at 5 to 20 percent of circumcised boys.[1]

References
  1. Frisch M, Simonsen. Cultural background, non-therapeutic circumcision and the risk of meatal stenosis and other urethral stricture disease: Two nationwide register-based cohort studies in Denmark 1977e2013. The Surgeon. 2016. doi:10.1016/j.surge.2016.11.002. PMID 28017691. Published online ahead of print on 22 December 2016.
  2. Van Howe RS. Incidence of meatal stenosis following neonatal circumcision in a primary care setting. Clin Pediatr (Phila). 2006;45(1):49–54. doi:10.1177/000992280604500108. PMID 16429216.
  3. Saeedi P, Ahmadnia H, Akhavan Rezayat A. Evaluation of the effect of meatal stenosis on the urinary tract by using ultrasonography. Urol J. 2017;14(3):3071–3074. doi:10.22037/uj.v14i3.3866. PMID 28537045.
  4. Meir DB, Livne PM. Is prophylactic antimicrobial treatment necessary after hypospadias repair?. The Journal of Urology. June 2004;171(6 part 2):2621–2622. doi:10.1097/01.ju.0000124007.55430.d3. PMID 15118434.
  5. Jayanth VR. The modified Snodgrass hypospadias repair: reducing the risk of fistula and meatal stenosis. The Journal of Urology. October 2003;170(4 part 2):1603–1605; discussion 1605. doi:10.1097/01.ju.0000085260.52825.73. PMID 14501672.
  6. Koenig JF. EMedicine. Meatal stenosis; 22 September 2016 [Retrieved 21 August 2017].
  7. Searles JM, MacKinnon AE. Home-dilatation of the urethral meatus in boys. BJU Int. March 2004;93(4):596–597. doi:10.1111/j.1464-410X.2003.04680.x. PMID 15008738.
  8. Griffiths DM, Atwell JD, Freeman NV. A prospective survey of the indications and morbidity of circumcision in children. Eur Urol. 1985;11(3):184–7. doi:10.1159/000472487. PMID 4029234.
  9. Sörensen SM, Sörensen MR. Circumcision with the Plastibell device. A long-term follow-up. Int Urol Nephrol. 1988;20(2):159–66. doi:10.1007/BF02550667. PMID 3384610.
  10. Cathcart P, Nuttall M, van der Meulen J, Emberton M, Kenny SE. Trends in paediatric circumcision and its complications in England between 1997 and 2003. Br J Surg. July 2006;93(7):885–90. doi:10.1002/bjs.5369. PMID 16673355.
  11. Yegane RA, Kheirollahi AR, Salehi NA, et al. Late complications of circumcision in Iran. Pediatr Surg Int. May 2006;22(5):442–445. doi:10.1007/s00383-006-1672-1. PMID 16649052.
  12. Simforoosh N, Tabibi A, Khalili SA, et al. Neonatal circumcision reduces the incidence of asymptomatic urinary tract infection: A large prospective study with long-term follow up using Plastibell. J Pediatr Urol. November 2010;8(3):320–3. doi:10.1016/j.jpurol.2010.10.008. PMID 21115400.
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