Ectopic Ureteral Opening

　　Pathogenesis

　　In the fourth week of embryogenesis, the distal end of the mesonephric duct, the ureteric bud, grows rapidly to form the ureter, and its distal part develops into the renal pelvis, calyces, and collecting tubules; in abnormalities, the mesonephric duct also gives off a supernumerary ureteric bud, rising in parallel with the normal ureteric bud, not only forming a double ureteral malformation but also because the lower part of the mesonephric duct forms part of the bladder and evolves into the male urethra, seminal vesicle, and ejaculatory duct, and the female's part of the urethra, vestibule, vagina, and uterus, so the duplicated ureter can open into the aforementioned organs. The male anterior urethra is developed from the urogenital sinus, so the ectopic ureter in males will not open on the distal side of the external urethral sphincter, therefore no dribbling urine occurs; while the female urethra is mainly formed from the lower end of the cloaca, so the ectopic ureter in females can open on the distal side of the voluntary sphincter, causing dribbling urine.

　　Ectopic ureteral orifices often occur with other malformations, such as anal atresia and tracheoesophageal fistula, and are occasionally seen in patients with solitary kidneys.

　　1, Anal atresia:Also known as low rectal anal atresia, due to abnormal development of the primitive anus, the anal canal is not formed, causing the rectum to be不通 with the outside world. In traditional Chinese medicine, it is called 'anus closure'.

　　2, Tracheoesophageal fistula:It is due to congenital embryonic developmental abnormalities, with the trachea and esophagus connected by a fistula. About half of the patients have other congenital malformations, such as cardiovascular, urogenital, and pulmonary hypoplasia. Most are sporadic, and only a few have a family history.

　　3, Solitary kidney:A compensatory hypertrophic solitary kidney can fully meet the normal physiological needs, without affecting life, and can be asymptomatic, often not discovered throughout life. Occasionally, it is discovered only after thorough urological examination due to concurrent infection, trauma, calculus, hydronephrosis, or tuberculosis in the contralateral kidney.

　　Most ectopic ureteral orifices in males are above the external sphincter, and there are generally no obvious clinical symptoms, mainly urinary tract infections. They can also produce varying degrees of lumbar sacral pain and recurrent epididymitis. In females, it is mainly manifested as normal urination accompanied by persistent urinary incontinence and urinary tract infections, leading to vulvar skin eczema and erosion. A careful examination can find pinpoint-like small orifices in the female vestibule, vagina, and urethra, with urine dripping out like dewdrops continuously.

　　The etiology of this disease is unclear, and it is related to autosomal recessive inheritance. It is usually associated with consanguineous marriage, and the disease cannot be prevented directly. Genetic screening should be performed for patients with a suspected family history of chromosomal abnormalities to avoid offspring suffering from the disease due to chromosomal inheritance. At the same time, attention should be paid to strengthening prenatal nutrition, a reasonable diet, and avoiding adverse stimuli that affect embryonic development, such as emotional excitement.

　　In addition to the general routine physical examination, special attention should be paid to the patience in examining the vulva, carefully searching for ectopic ureteral orifices. If a ureteral catheter is inserted into the suspected ectopic orifice for an urogram, it is generally difficult to find.

　　When there is urinary tract infection, urinalysis can show leukocytes, and urine culture can show the growth of pathogenic bacteria.

　　1. Intravenous urography

　　Can understand the type and position of the ectopic ureteral orifice, the development and hydronephrosis of the corresponding duplicated upper renal segment of the ectopic ureteral orifice, and can also understand the condition of concurrent duplicated kidney with double ureters.

　　2. CT examination

　　Can understand the size, shape, renal cortex thickness of the affected kidney, especially for cases where IVP is not visible.

　　3. Cystoscopy and retrograde pyelography

　　Understand whether there is an ectopic orifice opening into the bladder.

　　1. Related to congenital developmental abnormalities, it is necessary to pay attention to doing well pre-natal examinations, and if abnormalities are found, consider terminating the pregnancy appropriately.

　　2. Pregnant women should avoid spicy and刺激性 foods, fried and roasted foods, smoking and drinking, and other unhealthy dietary and lifestyle habits. During pregnancy, they should avoid contact with radioactive sources, toxic and harmful substances, etc., to prevent affecting the healthy development of the embryo and causing malformations.

　　3. If the patient has no special dietary requirements, they can maintain a normal diet, eat more vegetables and fruits, and ensure sufficient nutrition.

　　Surgery is the only method for treating ureteral ectopia of the orifice. Liu Wenshan from China and Gross from abroad believe that ureteral ectopia of the orifice belongs to part of the duplication malformation and is often accompanied by irreversible pathological changes, so the ureter should not be transplanted into the bladder or anastomosed with the normal ureter. However, Dodson believes that if the renal function has not been damaged, it is very reasonable to use ureterovesical anastomosis. Specific surgical plans should be formulated according to various different types of ectopic orifices and the severity of renal and ureteral lesions. The basic principles are:

　　1. If there is severe infection on the affected side, significant hydronephrosis of the renal pelvis and ureter, basically lost renal function, and the function of the contralateral kidney is confirmed to be good, then nephrectomy on the affected side can be performed, and if it is a duplicated kidney, then nephrectomy of the upper renal segment of the duplicated kidney should be performed. Both should try to remove most of the ureter to avoid the occurrence of ureteral stump syndrome. Phenol cautery of the residual ureteral mucosa or electrocoagulation of the residual mucosa can prevent infection of the ligated ureteral stump.

　　2. If the renal function is good or the damage is not serious, the kidney should be preserved, and options such as ureteroureteral anastomosis or ureterovesical reimplantation with anti-reflux surgery can be selected.