Urethral meatal stenosis is a narrowing (
stenosis
A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture).
''Stricture' ...
) of the opening of the
urethra
The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra ...
at the external
meatus , thus constricting the opening through which
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellul ...
leaves the body from the
urinary bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine ent ...
.
Symptoms and signs
* 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
Dysuria refers to painful or uncomfortable urination.
It is one of a constellation of ''irritative'' bladder symptoms (also sometimes referred to as lower urinary tract symptoms), which includes nocturia and urinary frequency.
Diagnosis
The cl ...
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
In male human anatomy, the foreskin, also known as the prepuce, is the double-layered fold of skin, mucosal and muscular tissue at the distal end of the human penis that covers the glans and the urinary meatus. The foreskin is attached to the ...
for the
glans penis
In male human anatomy, the glans penis, commonly referred to as the glans, is the bulbous structure at the distal end of the human penis that is the human male's most sensitive erogenous zone and their primary anatomical source of sexual p ...
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 (nappy) that produces blister formation and ulceration of the urethral opening, which eventually gives rise to meatal stenosis (a narrowing of the opening).
[ Published online ahead of print on 22 December 2016.] Meatal stenosis may also be caused by
ischemia
Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems w ...
resulting from damage to the
frenular artery during circumcision.
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.
Diagnosis
In males, history and
physical exam is adequate to make the
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine "cause and effect". In systems enginee ...
. In females, VCUG (
voiding cystourethrogram) is usually diagnostic. Other tests may include:
*
Urine analysis
* Urine culture
*
CBC, basic metabolic panel
* Renal and bladder
ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
Prevention
In the newborn
According to Frisch & Simonsen (2016), "the foreskin is protective against urinary stricture disease" (meatal stenosis).
Frisch & Simonsen (2016) call for a "thorough reassessment of the burden of urethral troubles and other adverse outcomes after non-therapeutic circumcision of boys."
After hypospadias repair
Meir & Livne (2004) suggest that use of a broad spectrum antibiotic after
hypospadias
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abo ...
repair will "probably reduce meatal stenosis
ates, while Jayanthi (2003) recommends the use of a modified Snodgrass hypospadias repair.
Treatment
In females, meatal stenosis can usually be treated in the physician's office using
local anesthesia
Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It ...
to numb the area and dilating (widening) the urethral opening with special instruments.
In males, it is treated by a second surgical procedure called
meatotomy
A meatotomy () is a form of penile modification in which the underside of the glans is split, extending the urinary meatus. The procedure may be performed by a doctor to alleviate meatal stenosis or urethral stricture. A meatotomy is sometimes ...
in which the meatus is crushed with a straight mosquito hemostat and then divided with fine-tipped scissors.
Recently, home-dilatation has been shown to be a successful treatment for most boys.
Prognosis
Most people can expect normal urination after treatment.
Incidence
Numerous studies over a long period of time clearly indicate that male
circumcision
Circumcision is a procedure that removes the foreskin from the human penis. In the most common form of the operation, the foreskin is extended with forceps, then a circumcision device may be placed, after which the foreskin is excised. Topi ...
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.
Sörensen & Sörensen (1988) reported 0 percent.
Cathcart ''et al''. (2006) reported an incidence of 0.55 percent. Yegane ''et al''. (2006) reported an incidence of 0.9 percent.
Van Howe (2006) reported an incidence of 7.29 percent.
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.
According to Emedicine (2016), the incidence of meatal stenosis runs from 9 to 20 percent.
Frisch & Simonsen (2016) placed the incidence at 5 to 20 percent of circumcised boys.
References
External links
{{DEFAULTSORT:Meatal Stenosis
Urethra disorders