Paraphimosis 

Paraphimosis (see image below), also known as capistration, is an uncommon condition in which the foreskin, once pulled back behind the glans penis, cannot be brought down to its original position, thus constituting one of the few urologic emergencies encountered in general practice. Like phimosis, paraphimosis occurs only in uncircumcised or partially circumcised males.^[1]

Paraphimosis differs from phimosis, a nonemergent condition in which the foreskin cannot be retracted behind the glans penis.

Patients with mild forms of paraphimosis can expect excellent outcomes; however, severe paraphimosis can lead to dire consequences. Therefore, paraphimosis should be viewed as a urologic emergency.

Paraphimosis may occur when the foreskin has been pulled back behind the head of the penis for an extended period and is often caused by well-meaning health professionals secondary to penile examination or urethral instrumentation.

When paraphimosis is suspected, immediately obtain a urology consult for proper evaluation and diagnosis. Prompt attention and treatment of this emergency should lead to a favorable outcome.

Frequency

Paraphimosis is a relatively uncommon condition and is less common than phimosis.

Paraphimosis is almost always an iatrogenically or inadvertently induced condition; however, case reports have described coital paraphimosis leading to penile necrosis,^[2] as well as penile piercings leading to paraphimosis.^[3] Paraphimosis occurs more often in hospitals and nursing homes than in the private community, where the affected individual or a parent often retracts the prepuce and then inadvertently leaves it in its retracted position. In most cases, the foreskin reduces on its own and therefore precludes paraphimosis; however, if the slightest resistance to retraction of the prepuce is present, leaving it in this state predisposes it to paraphimosis. As edema accumulates, the condition worsens.

According to the National Hospital Discharge Survey, a trend in the United States over the last 30-40 years has been toward noncircumcision. Circumcision rates, which were at an all-time high of 78%-80% in the mid-to-late 1960s, decreased to 55%-60% in 2003. With an increase in the number of uncircumcised individuals, paraphimosis has the potential to become more common. Because paraphimosis is a condition that is almost always iatrogenically or inadvertently induced, simple education and clarification of proper prepuce care to parents, the individuals themselves, and health care professionals may be all that is required to prevent this problem.

Most frequently, paraphimosis occurs after retraction of the foreskin during detailed penile examination, cleaning, urethral catheterization, or cystoscopy. Being prudent with foreskin manipulation is the most important key in preventing paraphimosis.

Development of paraphimosis after catheterization is not uncommon. Before the insertion of a urethral catheter, a health professional retracts the foreskin to sterilely prepare and drape the glans penis. The retracted foreskin may be left in that manner for several hours to days. The failure to restore the prepuce to its original position sometimes leads to the development of paraphimosis.

A more unusual cause of paraphimosis is self-infliction, such as piercing with a penile ring into the glans. Paraphimosis secondary to erections has also been reported.

When the foreskin becomes trapped behind the corona for a prolonged period, a tight band of tissue forms around the penis. This constricting ring initially impairs venous blood and lymphatic flow from the glans penis and prepuce, in turn causing edema of the glans. As the edema worsens, arterial blood flow becomes compromised. The ensuing tissue ischemia and vascular engorgement cause painful swelling of the glans and prepuce and may eventually lead to gangrene or autoamputation of the distal penis.

When diagnosed early, paraphimosis can be remedied easily with simple manual reduction in combination with other conservative measures.

Patients with severe paraphimosis that proves refractory to conservative therapy will require a bedside emergency dorsal slit procedure to save the penis. A formal circumcision can be performed in the operating room at a later date.

Adult patients with symptomatic paraphimosis most often report penile pain.

In the pediatric population, paraphimosis may manifest as acute urinary tract obstruction and may be reported as obstructive voiding symptoms.

On examination, the glans penis is enlarged and congested with a collar of edematous foreskin. A constricting band of tissue is noted directly behind the head of the penis. The remainder of the penile shaft is unremarkable. An indwelling urethral catheter is often present. Simply removing the catheter may help treat paraphimosis caused by an indwelling urethral catheter. The image below depicts mild-to-moderate paraphimosis.

If paraphimosis is left untreated for too long, necrosis of the glans penis can occur. Partial amputation of the distal penis has been reported. The image below depicts severe paraphimosis.

Indications for an emergency dorsal slit procedure include phimosis and paraphimosis that have proven refractory to more conservative measures.

Emergency dorsal slit procedures are generally reserved for severe or complex paraphimosis.

At a later date, a formal circumcision can be performed as an outpatient procedure. Prepuce-sparing procedures have been described and may be appropriate if the individual must retain intact foreskin; however, the best way to ensure that paraphimosis will not recur is to perform circumcision.^[4]

The penis is divided into 3 parts.

• The root of the penis lies under the pubic bone and provides stability when the penis is erect.
• The body of the penis constitutes the major portion of the penis and is composed of 2 cavernosal bodies (ie, corpora cavernosa) and a corpus spongiosum (ie, head of the penis). The male urethra traverses through the corpus spongiosum and exits from the meatus. The cavernosal bodies produce an erection when filled with blood.
• The glans is the distal expansion of the corpus spongiosum usually covered by the loose skin of the prepuce in uncircumcised individuals. A collar of tissue immediately behind the glans penis is known as the coronal sulcus.

The penis is innervated by the left and right dorsal nerves (main sensory nerve supply), which are branches of the pudendal nerve.

The penis is a highly vascular organ supplied by the internal pudendal artery, which arises from the internal iliac artery and then branches into the deep penile artery, the bulbar artery, and the urethral artery.

The deep penile artery becomes the cavernosal arteries, which supply the entire corpus cavernosum. The urethral artery supplies the glans penis and the corpus spongiosum. The bulbar artery nourishes the bulbar urethra and the bulbospongiosus muscle.

Do not consider circumcision in a neonate with hypospadias, a dorsal hood deformity, or a small penis. Refer the neonate to a urologist.