Recurrent urethra

　　The true cause of duplicated urethra is not yet fully clear, with various theories, but each theory cannot explain the occurrence cause of all types. The main theories are as follows.

　　One, Das (1977) believes that during the process of embryonic urethral development, the development of the penis and the urethral plate is unbalanced and not coordinated, resulting in the following three situations.

　　1. The urogenital sinus has developed, while the urethral ridge is delayed in development. Because the penis has developed, the urogenital sinus also develops forward with the penis, forming the accessory urethra. After the accessory urethra is formed, the urethral ridge begins to develop, forming the normal urethra. As a result, it becomes the first type of duplicated urethra.

　　2. The fusion of the genital ridges leads to the crossing of the urethra, resulting in the second type of incomplete duplicated urethra.

　　3. The Wolffian duct and the Müllerian duct play an important role in the differentiation of male and female urethras. The Wolffian duct is dominant, developing into the female urethra. During the development of the urethra, if the Wolffian duct is initially in a disadvantageous position, the urethra will open at the perineum. Subsequently, if the Wolffian duct changes from a disadvantageous to a dominant position, the urethra will develop along with the penis into a male urethra, resulting in duplicated urethra. One urethra opens at the perineum, and the other urethra develops with the penis, opening at the glans penis, which is the third type of duplicated urethra.

　　Two, Wilson believes (1971) that the urorectal septum separates the perineal cavity into two compartments, with the anterior compartment developing into the bladder and posterior urethra, and the posterior compartment developing into the anal rectum. The urogenital diaphragm terminates at the perineal membrane. If it continues to develop downward, the urethra will also be divided into two parts, forming duplicated urethra, that is, the first type of duplicated urethra.

　　Three, the stroma inserts from the side of the urethral primordium, dividing the urethra into two lumens in front and back (Tripathi, 1969).

　　Four, the crossing of the urethral groove during embryogenesis forms the second type of duplicated urethra (Moog, 1968).

　　Duplicated urethra often complicates with other organ malformations, such as renal and ureteral malformations, double bladders, double penises (double clitorises), incomplete uterine development, absence of vagina, ectopic reproductive glands, spinal and intestinal malformations, etc. Therefore, a comprehensive examination should be conducted. Other complications such as urethral diverticula, which also have two stages of urination, but cystography and voiding cystourethrography can show the absence of diverticula in the bladder and cystic masses in the urethra. Urethral cystoscopy shows that the opening of the diverticulum is in the urethra rather than in the bladder.

　　The clinical manifestations of duplicated urethra are not consistent and are related to its type. The most common symptoms are urethral infection and poor flow of accessory urethral urine. Therefore, the accessory urethra often has infections, which are often a focus of chronic urinary tract infection due to the hidden nature of the lesion.

　　The hypoplasia of the smooth muscle of the accessory urethra in the first type of duplicated urethra affects about half of the patients, with urinary incontinence ranging from mild stress incontinence to complete incontinence. In the second type, if the accessory urethra becomes inflamed, edema of the mucosa at the urethral bifurcation or accumulation of secretions in the accessory urethra can compress the normal urethra, causing difficulty in urination and symptoms of urethral obstruction..

　　The true cause of duplicated urethra is not yet fully clear, there are many theories, but each theory cannot explain the occurrence reasons of all types, so it is impossible to prevent this disease directly. Early detection, early diagnosis, and early treatment are of great significance for the indirect prevention of this disease. Regular checks should be done during pregnancy. If the child has a tendency of developmental abnormality, after being confirmed by B-ultrasound, induced abortion can be chosen for severe cases to avoid the birth of children with the disease.

　　Duplicated urethra can be determined by retrograde urethrogram and micturating cystourethrogram to determine the relationship between the accessory urethra and the normal urethra. After injecting methylene blue through the orifice of the accessory urethra, then urinating, it can be determined whether the accessory urethra communicates with the normal urethra and bladder. During cystoscopy, methylene blue is injected into the accessory urethra, which makes it easier to see the position of the orifice of the accessory urethra in the urethra. Using a urethral probe, it can also be detected simultaneously from the orifice of the accessory urethra and the normal urethra, and their relationship can also be detected.

　　In addition to conventional treatment, patients with duplicated urethra should also pay attention to the following aspects in diet: diet should be light, eat more vegetables and fruits, rationally match the diet, and ensure adequate nutrition.

　　The treatment of duplicated urethra should be considered separately according to the lesions and signs, with the aim of maintaining a functional urethra. For those with asymptomatic first type accessory urethra, treatment may not be required. For those with mild infection, antibiotic treatment can be used. For those with severe symptoms, the accessory urethra can be resected or cauterized with an electrocoagulator, and a sclerosing agent can be injected to seal the accessory urethra, but this may worsen the downward curvature of the penis and cause pain during erection.

　　For those with the external orifice of the second type accessory urethra at the tip of the penis, the interval between the two urethras can be incised to make the two urethras into one. For those with accessory urethra opening at the penis, the distal urethra is cord-like. If there is penile deformity, cord-like urethra resection is required to correct the downward curvature of the penis. For those with the second type accessory urethra leading to the perineum, it can be simply resected. For those leading to the rectum, the accessory urethra can be resected, and the urethral rectal fistula can be repaired.