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Posterior urethral valve (PUV) disorder is an obstructive developmental anomaly in the urethra and genitourinary system of male newborns. A posterior urethral valve is an obstructing membrane in the posterior male urethra as a result of abnormal "in utero" development. It is the most common cause of bladder outlet obstruction in male newborns. The disorder varies in degree, with mild cases presenting late due to milder symptoms. More severe cases can have renal and respiratory failure from lung underdevelopment as result of low amniotic fluid volumes, requiring intensive care and close monitoring. It occurs in about one in 8000 babies.
Urethral diverticula are often asymptomatic and symptoms that are present tend to be nonspecific. They can co-occur with cancer, in approximately 6-9% of cases, most commonly adenocarcinoma, but also including squamous cell carcinoma and transitional cell carcinoma. Approximately 10% of cases co-occur with kidney stones.
There are 2 types of urethral diverticulums. Congenital and acquired. In infancy usually the urethral diverticulum is congenital but in rare instances acquired urethral diverticulum can be seen in infancy specially following traumatic catheterization.
Common symptoms of urethral diverticulum include incontinence, urinary frequency and urgency, pain during sex, and pain during urination. Other symptoms include pain localized to the urethra or pelvis and frequent urinary tract infection.
When urethral diverticulum becomes severe, a painful mass can sometimes be felt inside the introitus of the vagina, which can discharge pus. If the mass is hard or bleeds, complications like cancer or kidney stones may be present.
Posterior urethral obstruction was first classified by H. H. Young in 1919. The "verumontanum", or mountain ridge, is a distinctive landmark in the prostatic urethra, important in the systemic division of posterior valve disorders:
- Type I - Most common type; due to anterior fusing of the "plicae colliculi", mucosal fins extending from the bottom of the verumontanum distally along the prostatic and membranous urethra
- Type II - Least common variant; vertical or longitudinal folds between the verumontanum and proximal prostatic urethra and bladder neck
- Type III - Less common variant; a disc of tissue distal to verumontanum, also theorized to be a developmental anomaly of congenital urogenital remnants in the bulbar urethra
Dewan has suggested that obstruction in the posterior urethra is more appropriately termed congenital obstructions of the posterior urethral membrane (COPUMs), a concept that has come from an in-depth analysis of the historical papers, and evaluation of patients with a prenatal diagnosis that has facilitated video recording of the uninstrumented obstructed urethra. The congenital obstructive lesions in the bulbar urethra, named Type III Valves by Young in 1919, have been eponymously referred to as Cobb's collar or Moorman's ring. For each of the COPUM (Posterior Urethra) and Cobb's (Bulbar Urethra) lesions, the degree of obstruction can be variable, consistent with a variable expression of the embryopathy. The now nearly one hundred year old nomenclature of posterior urethral valves was based on limited radiology and primitive endoscopy, thus a change COPUM or Cobb's has been appropriate.
There are several forms of imperforate anus and anorectal malformations. The new classification is in relation of the type of associated fistula.
The classical Wingspread classification was in low and high anomalies:
- A low lesion, in which the colon remains close to the skin. In this case, there may be a stenosis (narrowing) of the anus, or the anus may be missing altogether, with the rectum ending in a blind pouch.
- A high lesion, in which the colon is higher up in the pelvis and there is a fistula connecting the rectum and the bladder, urethra or the vagina.
- A persistent cloaca (from the term cloaca, an analogous orifice in reptiles and amphibians), in which the rectum, vagina and urinary tract are joined into a single channel.
Imperforate anus is usually present along with other birth defects—spinal problems, heart problems, tracheoesophageal fistula, esophageal atresia, renal anomalies, and limb anomalies are among the possibilities.
Imperforate anus is associated with an increased incidence of some other specific anomalies as well, together being called the VACTERL association:
- V – Vertebral anomalies
- A – "Anal atresia"
- C – Cardiovascular anomalies
- T – Tracheoesophageal fistula
- E – Esophageal atresia
- R – Renal (kidney) and/or radial anomalies
- L – Limb defects
Other entities associated with an imperforate anus are trisomies 18 and 21, the cat-eye syndrome (partial trisomy or tetrasomy of a maternally derived number 22 chromosome), Baller-Gerold syndrome, Currarino syndrome, caudal regression syndrome, FG syndrome, Johanson-Blizzard syndrome, McKusick-Kaufman syndrome, Pallister-Hall syndrome, short rib-polydactyly syndrome type 1, Townes-Brocks syndrome, 13q deletion syndrome, urorectal septum malformation sequence, and the OEIS complex (omphalocele, exstrophy of the cloaca, imperforate anus, spinal defects).
A urethral diverticulum is a condition where the urethra or the periurethral glands push into the connective tissue layers (fascia) that surround it.
Symptoms and signs in the newborn can be sepsis, abdominal mass, and respiratory distress. Other abdominopelvic or perineal congenital anomalies frequently prompt radiographic evaluation in the newborn, resulting in a diagnosis of coincident vaginal atresia. Symptoms for vaginal atresia include cyclical abdominal pain, the inability to start having menstrual cycles, a small pouch or dimple where a vaginal opening should be, and pelvic mass when the upper vagina becomes filled with menstrual blood. Signs and symptoms of vaginal atresia or vaginal agenesis can often go unnoticed in females until they reach the age of menstruation. Women may also experience some form of abdominal pain or cramping.
Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent.
Examples of atresia include:
- Biliary atresia, a condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent.
- Choanal atresia, blockage of the back of the nasal passage, usually by abnormal bony or soft tissue.
- Esophageal atresia, which affects the alimentary tract and causes the esophagus to end before connecting normally to the stomach.
- Imperforate anus, malformation of the opening between the rectum and anus.
- Intestinal atresia, malformation of the intestine, usually resulting from a vascular accident in utero.
- Microtia, absence of the ear canal or failure of the canal to be tubular or fully formed (can be related to Microtia, a congenital deformity of the pinna, or outer ear).
- Ovarian follicle atresia, the degeneration and subsequent resorption of one or more immature ovarian follicles.
- Potter sequence, congenital decreased size of the kidney leading to absolutely no functionality of the kidney, usually related to a single kidney.
- Pulmonary atresia, malformation of the pulmonary valve in which the valve orifice fails to develop.
- Renal agenesis, only having one kidney.
- Tricuspid atresia, a form of congenital heart disease whereby there is a complete absence of the tricuspid valve, and consequently an absence of the right atrioventricular connection.
- Vaginal atresia, a congenital occlusion of the vagina or subsequent adhesion of the walls of the vagina, resulting in its occlusion.
The hallmark sign of urethral stricture is a weak urinary stream. Other symptoms include:
- Splaying of the urinary stream
- Urinary frequency
- Urinary urgency
- Straining to urinate
- Pain during urination
- Urinary tract infection
- Prostatitis
- Inability to completely empty the bladder.
Some patients with severe urethral strictures are completely unable to urinate. This is referred to as acute urinary retention, and is a medical emergency. Hydronephrosis and renal failure may also occur.
Vaginal atresia can sometimes be diagnosed by physical examination soon after birth. A child with vaginal atresia often has other congenital abnormalities and other tests such as x-ray and tests to evaluate the kidney are done. Findings in adolescents may include abdominal pain, difficulty voiding, and backache, but most present with amenorrhea. Difficulties with sexual intercourse can suggest atresia. In the event that the condition is not caught shortly after birth, vaginal atresia becomes more evident when no menstrual cycle is occurs. If vaginal atresia is suspected by the doctor, a blood test may also be request for any of the previously mentioned syndromes, a magnetic resonance imaging (MRI) test, or an ultrasound. A regular evaluation of children born with an imperforate anus or anorectal malformation should be paired with the assessment of the results from these tests.
Prenatally diagnosed hydronephrosis (fluid-filled kidneys) suggest post-natal follow-up examination.
The strongest neo-natal presentation is urinary tract infection. A hydronephrotic kidney may present as a palpable abdominal mass in the newborn, and may suggest an ectopic ureter or ureterocele.
In older children, ureteral duplication may present as:
- Urinary tract infection - most commonly due to vesicoureteral reflux (flow of urine from the bladder into the ureter, rather than vice versa).
- Urinary incontinence in females occurs in cases of ectopic ureter entering the vagina, urethra or vestibule.
Urethral strictures most commonly result from injury, urethral instrumentation, infection, non-infectious inflammatory conditions of the urethra, and after prior hypospadias surgery. Less common causes include congenital urethral strictures and those resulting from malignancy.
Urethral strictures after blunt trauma can generally be divided into two sub-types;
- Pelvic fracture-associated urethral disruption occurs in as many as 15% of severe pelvic fractures. These injuries are typically managed with suprapubic tube placement and delayed urethroplasty 3 months later. Early endoscopic realignment may be used in select cases instead of a suprapubic tube, but these patients should be monitored closely as vast majority of them will require urethroplasty.
- Blunt trauma to the perineum compresses the bulbar urethra against the pubic symphysis, causing a "crush" injury. These patients are typically treated with suprapubic tube and delayed urethroplasty.
Other specific causes of urethral stricture include:
- Instrumentation (e.g., after transurethral resection of prostate, transurethral resection of bladder tumor, or endoscopic kidney surgery)
- Infection (typically with Gonorrhea)
- Lichen sclerosus
- Surgery to address hypospadias can result in a delayed urethral stricture, even decades after the original surgery.
Where a urethrocele causes difficulty in urinating, this can lead to cystitis.
There are often no symptoms associated with a urethrocele. When present, symptoms include stress incontinence, increased urinary frequency, and urinary retention (difficulty in emptying the bladder). Pain during sexual intercourse may also occur.
Ureteral duplication is either:
- Partial - i.e. the two ureters drain into the bladder via a single common ureter. Partial, or incomplete, ureteral duplication is rarely clinically significant.
- Complete - in which the two ureters drain separately. Complete ureteral duplication may result in one ureter opening normally into the bladder, and the other being ectopic, ending in the vagina, the urethra or the vulval vestibule. These cases occur when the ureteric bud arises twice (rather than splitting).
Ectopic ureter (or ureteral ectopia) is a medical condition where the ureter, rather than terminating at the urinary bladder, terminates at a different site. In males this site is usually the urethra, in females this is usually the urethra or vagina. It can be associated with renal dysplasia, frequent urinary tract infections, and urinary incontinence (usually continuous drip incontinence). Ectopic ureters are found in 1 of every 2000–4000 patients, and can be difficult to diagnose, but are most often seen on CT scans.
Ectopic ureter is commonly a result of a duplicated renal collecting system, a duplex kidney with 2 ureters. In this case, usually one ureter drains correctly to the bladder, with the duplicated ureter presenting as ectopic.
Hydrocolpos is the distension of the vagina caused by accumulation of fluid due to congenital vaginal obstruction. The obstruction is often caused by an imperforate hymen or less commonly a transverse vaginal septum. The fluid consists of cervical and endometrial mucus or in rare instances urine accumulated through a vesicovaginal fistula proximal to the obstruction. In some cases it is associated with Bardet-Biedl Syndrome. If it occurs in prepubertal girls, it may show up as abdominal swelling. It may be detected by using ultrasound. It may also present at birth as a distended lower abdomen and vagina. It also associated with vaginal atresia.
A prostatic stent is a stent used to keep open the male urethra and allow the passing of urine in cases of prostatic obstruction and lower urinary tract symptoms (LUTS). Prostatic obstruction is a common condition with a variety of causes. Benign prostatic hyperplasia (BPH) is the most common cause, but obstruction may also occur acutely after treatment for BPH such as transurethral needle ablation of the prostate (TUNA), transurethral resection of the prostate (TURP), transurethral microwave thermotherapy (TUMT), prostate cancer or after radiation therapy.
Despite the similarity of name, an epispadias is not a type of hypospadias, and involves a problem with a different set of embryologic processes.
Women can also have this type of congenital malformation. Epispadias of the female may occur when the urethra develops too far anteriorly, exiting in the clitoris or even more forward. For females, this may not cause difficulty in urination but may cause problems with sexual satisfaction. Frequently, the clitoris is bifurcated at the site of urethral exit, and therefore clitoral sensation is less intense during sexual intercourse due to frequent stimulation during urination. However, with proper stimulation, using either manual or positional techniques, clitoral orgasm is definitely possible.
Most cases involve a small and bifid penis, which requires surgical closure soon after birth, often including a reconstruction of the urethra. Where it is part of a larger exstrophy, not only the urethra but also the bladder (bladder exstrophy) or the entire perineum (cloacal exstrophy) are open and exposed on birth, requiring closure.
Surgical repair can sometimes result in complications, including:
- Stricture, due to gastric acid erosion of the shortened esophagus
- Leak of contents at the point of anastomosis
- Recurrence of fistula
- Gastro-esophageal reflux disease
- Dysphagia
- Asthma-like symptoms, such as persistent coughing/wheezing
- Recurrent chest infections
- Tracheomalacia
Bulbar urethral necrosis is a problem that can occur after a pelvic fracture associated urethral distraction defect (PFUDD).
Other birth defects may co-exist, particularly in the heart, but sometimes also in the anus, spinal column, or kidneys. This is known as VACTERL association because of the involvement of Vertebral column, Anorectal, Cardiac, Tracheal, Esophageal, Renal, and Limbs. It is associated with polyhydramnios in the third trimester.
It is usually considered a congenital malformation of unknown cause. Since at an early stage of fetal development the penis is curved downward, it has been proposed that chordee results from an arrest of penile development at that stage.
The curvature of a chordee can involve
1. tethering of the skin with urethra and corpora of normal size;
2. curvature induced by fibrosis and contracture of the fascial tissue (Buck's fascia or dartos) surrounding the urethra;
3. disproportionately large corpora in relation to the urethral length without other demonstrable abnormality of either; or
4. a short, fibrotic urethra that tethers the penis downward (the least common type).
Severe degrees of chordee are usually associated with hypospadias, but mild degrees of curvature may occur in many otherwise normal males. When the curved penis is small and accompanied by hypospadias, deficiency of prenatal androgen effect can be inferred.
Patients with erectile dysfunction (ED) and PFUDD or patients with PFUDD and traumatic disruption of the dorsal arteries are susceptible to bulbar urethral necrosis. These patients need tubularized substitution urethroplasty, which is replacement of the bulbar urethra with a various number of tubularized flaps ranging from scrotal skin to sigmoid colon (and others).