Hypospadias in children

Introduction to hypospadias in children Hypospadias (hypospadias) is a urethral malformation, that is, the urethral opening in the proximal urethral opening of the penis to the perineum, which is one of the most common malformations in the genitourinary system of children. Despite the great progress in the surgical treatment of hypospadias, the treatment of hypospadias is far from satisfactory, from the perspective of the doctor or the child or his parents. basic knowledge Sickness ratio: 0.0012% Susceptible people: children Mode of infection: non-infectious Complications: inguinal hernia, ureteropelvic junction obstruction

Causes of hypospadias in children

(1) Causes of the disease

Genetic inheritance

There is a certain family tendency in the incidence of hypospadias, but the specific situation of the genes or chromosomes involved is still unclear. We have encountered several fathers or brothers, especially twins who have the disease, and 10% of them have been reported. There are hypospadias in the father and 15% of the children's brothers.

2. Hormone effects

The hormones produced from the fetal testis affect the formation of male external genitalia. The testis stromal cells (leydigs cells) are stimulated by chorionic gonadotropin to produce testosterone at the 8th week of pregnancy, which is then transformed into dihydrotestosterone. The development of the external genitalia is affected. The regulation of dihydrotestosterone, insufficient testosterone production, too late, or the abnormal process of testosterone conversion to dihydrotestosterone can lead to genital malformations, hypospadias often accompanied by cryptorchidism, and gender deformity is related to this, before the mother, Hormone application during pregnancy also has a certain impact on the development of the fetal reproductive system. The influence of environmental factors on the development of the urinary tract is mainly through the endocrine system of the mother and the fetus.

(two) pathogenesis

Embryology

At the 6th week of the embryo, there is a protrusion on the ventral side of the genitourinary sinus called the reproductive nodule. There is a shallow groove on the midline of the tail side of the reproductive nodule, called the urethral groove. The bulge on both sides of the urethral groove is urine. Reproductive pleats, embryos begin to differentiate into males or females after 7 and 8 weeks. Under the action of dihydrotestosterone, males develop genital nodules to form penis. The lower part of urogenital sinus extends into the penis and opens into the urethral groove. The urogenital pleats on both sides merge from the proximal end to the distal end to form the urethra. At this time, the outer urethra is moved to the coronal sulcus of the penis head. At the top of the penis head, a ectodermal layer grows inward, and then the cell cord is centered. Connected with the urethral groove, the outer urethra is moved to the top of the penis head. At the 12th week, the skin of the penis is reflexed, called the foreskin. The interstitial in the reproductive nodules differentiates into the corpus cavernosum and the corpus cavernosum. During the embryonic period, due to endocrine abnormalities or other causes of urethral groove insufficiency, the formation of hypospadias is formed. Because the formation of the distal end of the urethra is in the final stage, the urethral orifice is located at the distal end of the penis. Cases maximum.

2. Pathological changes

The pathological manifestations of hypospadias are mainly penile curvature and abnormalities of the urethra opening.

(1) Penis

The lower penis can exist alone, mostly an important lesion of the hypospadias. Sadlouski reported 64 cases of penile inferiority, 24 cases had no hypospadias, and Culp reported that 15% of the penis had no hypospadias. We also found that The lower penis of the hypospadias is a rare and special type, called the primary penile curvature. There are two types of primary penile curvature: one is the normal urethral cavernous body, which accounts for 2/ 3; the other type is accompanied by urethral hypoplasia, which accounts for 1/3. The first type is normal when the penis is loose, the glans is surrounded by the foreskin, the penis is bent under the erection, and the 90° curve is visible from the side view; The urethral opening is located in the normal position of the glans, but the foreskin can not be completely surrounded, the ventral foreskin of the penis is short, the skin covering the urethra is very thin, the urethra has no urethral cavernous body, and the artificial erection is present in the lower chord. Because the urethra is partially stunted, it can be considered It is a recessive hypospadias, or a congenital urethra shortening.

Once the penis is corrected, the urethral opening moves to the proximal ventral side of the penis to form a hypospadias. The lower penis usually forms a hard fiber cord or a fibrotic sector in the area between the hypospadias and the penis. As a result, the penis is difficult to stretch, and the severe hypospadias are more serious. Some people think that the fiber cord is a residue formed by the uterine corpus cavernosum development, which causes the penis body to adhere to the scrotal skin or foreskin, hindering the freedom of the penis. Sliding, causing bending, additional foreskin, Buck fascia, adhesion of the meat membrane to the urethral opening of the hypospadias, fibrosis is also an important factor causing the lower curvature of the penis. There are cavernous and penile fascia around the normal urethra. According to the degree of tissue defect around the urethra, Devine divides the penis into three grades: Grade I: there is only one layer of mucosa in the urethra, there are only some fibrous tissue around, lack of cavernous body, penile fascia and meat membrane tissue, grade II: urethral mucosa Complete, surrounded by corpus cavernosum, but lacking penile fascia and meat membrane tissue, grade III: urethral mucosa, urethral cavernosum, penile fascia Complete, but the lack of meat membrane tissue.

(2) hypospadias

Hypospadias is characterized by abnormal urethral opening. The abnormalities of the opening are mainly abnormal position and stenosis. The abnormal opening produces a urine flow that is deflected and spread to the ventral side of the penis, making it difficult to control the flow of urine, making it difficult for patients to stand and urinate. Types of hypospadias, abnormalities in opening abnormalities, coronal sulcus and glans type lower fissure combined with penile inferiority, penis body type, penis scrotum type, scrotum type or perineal type hypospadias, usually combined with severe penis song.

Pediatric hypospadias prevention

Birth defects are important factors affecting the health of infants and children, affecting the quality of the birth population. At present, there is no effective prevention method for this disease. In order to reduce the incidence of this disease, preventive measures refer to other birth defects diseases, and the prevention of birth defects should be Before pregnancy, before the birth, such as:

1. The pre-marital medical examination plays a positive role in preventing birth defects. The size depends on the examination items and contents, mainly including serological examination (such as hepatitis B virus, Treponema pallidum, HIV), reproductive system examination (such as screening for cervical inflammation). , general physical examination (such as blood pressure, electrocardiogram) and ask about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.

2. Pregnant women should avoid harmful factors including smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc. In the process of antenatal care during pregnancy, systematic screening of birth defects is required. Including regular ultrasound examination, serological screening, etc., if necessary, chromosome examination, if abnormal results occur, need to determine whether to terminate the pregnancy; fetal safety in the uterus; whether there is sequelae after birth, whether it can be treated, prognosis How to wait and take practical measures for diagnosis and treatment. Due to environmental pollution, a large number of crops use chemical fertilizers and growth promoters. The urethra cracking has been reported in Europe and the United States, and the state should make great efforts to control and prevent environmental pollution.

Pediatric hypospadias complications Complications inguinal hernia, ureteropelvic junction obstruction

The most common malformation associated with hypospadias is inguinal hernia and testicular insufficiency, each accounting for about 10%. The more severe the hypospadias, the higher the incidence of malformation. The lower urethra is associated with upper urinary tract. The incidence of malformations ranged from 1% to 3%, such as obstruction of the ureteropelvic junction, repeated deformities, etc., and a small number of patients with anorectal malformations.

Pediatric hypospadias symptoms common symptoms penile abnormalities and hermaphroditism

The clinical manifestations of hypospadias are very characteristic:

1. urethral opening ectopic: urethral ectopic opening in any part from the proximal end of the normal urethral opening to the perineum, part of the urethral opening has a slight stenosis, due to the surface of a very thin mucosal tissue is not completely covered, Sometimes a segment of the urethra is absent, its wall is thin, and the urinary line is generally backward. Therefore, the child often takes the sputum to urinate, and the urethral orifice is more obvious when it is located at the proximal end of the penis.

2. Penis to the ventral side: mainly due to the proliferation of urethral fibrosis at the distal end of the urethra, the lack of tissue in the ventral and urethral wall of the penis, and the back of the corpus cavernosum.

3. The foreskin is deposited on the dorsal side: the ventral foreskin of the penis head fails to fuse in the midline, and the foreskin ligament is absent. All the foreskin is transferred to the dorsal side of the penis and is cap-like. According to the position of the urethra, the hypospadias are divided into 4 types: Penis head type, penis body type, penis scrotum type and perineal type.

This type of typing is often difficult to accurately determine before surgery. In some cases, the penis is very severely curved. The urethral opening can still be located at the distal end of the penis. The child can even stand to urinate, but once the fiber cord is loosened, The urethral opening will fade to the proximal end of the penis. In order to facilitate the estimation of the surgical effect, the penis should be fully corrected, and then according to the position of the urethral opening after retraction.

Pediatric hypospadias examination

General laboratory routine examination is normal, when combined infection, urine test leukocytosis, male hypothalamic chromatin should be negative, sex chromosome is XY, urine 17-ketosteroids normal, gonadal biopsy testicular.

1.17 ketosteroid examination: 17 ketosteroids in the urine can be said to indicate adrenal hyperplasia, the possibility of female pseudohermaphroditism is the greatest, if the urinary 17 ketosteroids are normal, the possibility of female pseudohermaphroditism cannot be ruled out. Further examination.

2. Sex chromatin examination: commonly used oral mucosal epithelium, vaginal mucosal epithelium, skin or white blood cells, after special staining examination, on the inner surface of the nuclear membrane, there is a chromatin mass protrusion, diameter 0.5 ~ 1.0m, drum Symptoms, called sex chromatin, are significantly different between men and women (due to the different methods used for staining, the cells examined are different, so the constants are also different), female sex chromatin is more than 10% positive (called positive) And males below 5% (called negative), clinically used to identify gender, sexual chromatin is positive, can negate hypospadias, certainly female pseudohermaphroditism or true hermaphroditism, sexual chromatin is negative, It is still not clear that the hypospadias should be further differentiated from true hermaphroditism.

3. Sex chromosome examination: When conditions are available, it is best to have sex chromosome examination, which is more reliable than sex chromatin examination. If it is XX, it is definitely female, can exclude hypospadias. If it is XY, except for urethra In addition to the possibility of cracking, it is still necessary to distinguish it from true deformity.

4. Abdominal B-ultrasound: Check for ovaries, uterus, etc.

5. Endoscopy: vaginal fossa is seen in the posterior urethra, indicating the presence of the female genital tract; seeing the fine sputum, indicating that the male reproductive tract, if both exist, indicates that in addition to urethral malformations, there are also genital tracts If the deformity exists, it is necessary to continue the inspection.

6. Exploratory laparotomy and gonadal biopsy: Through the above examination, if 17 ketosteroids are normal, sex chromatin is negative, and sex chromosome is XY, laparotomy and gonadal biopsy should be performed to distinguish from true hermaphroditism.

Diagnosis and diagnosis of hypospadias in children

diagnosis

The diagnosis of hypospadias is not difficult due to the characteristic changes of its appearance. It is obvious that the key point is that the hypospadias may be the manifestation of some severe genitourinary malformations such as hermaphroditism, especially the severe hypospadias. The rate of malformation is high. It is necessary to pay attention to the identification of gender abnormalities. The genital manifestations are ambiguous. The hypospadias with cryptorchidism must first be examined by chromosomes. If it is clear for male 46XY, the testicular descending is fixed first. Gonadal biopsy, such as testicular, but poor development, coupled with the development of the penis is very small, it is necessary to discuss with the family, consider making women as well.

Differential diagnosis

1. Male pseudohermaphroditism: The chromosome is 46XY, the sex chromatin is negative, the gonad is the testis, but the internal and external genital development is abnormal. The external genital appearance can be like male or female. The male perineal hypospadias is actually male pseudohermaphroditism. Because of the incomplete development of the testis in the embryonic period, the lack of genital tract mechanized substances and male hormones, the vulva has different degrees of female signs, such as hypospadias, poor penis development, scrotal division, and testicular drop.

2. Female pseudohermaphroditism: Most of them are caused by adrenal hyperplasia caused by abnormal adrenal enzymes. Female hormones are impaired and androgen is increased. Therefore, the vulva develops to the male side. The vulva examination shows that the clitoris increases, such as the penis of the hypospadias. The urethral opening is located in the base of the hypertrophic clitoris. It is like a hypospadias. The vaginal stenosis is not easy to be found. The urogenital sinus exists. The front of the opening is connected with the urethra, the rear is connected with the uterus, the sex chromosome 46XX, the sex chromatin is positive, and the urine 17 The ketone excretion is increased. Some female pseudohermaphroditism is caused by the male hormone in the mother, but the female nucleus of the female pseudohermaphroditism is positive, the sex chromosome is XX, the gonad is the ovary, if there is adrenal hyperplasia, urine 17 ketosteroids increase, the treatment of this patient should be based on the principle of conversion to female vulva.

3. True hermaphroditism: There are testicles and ovaries. The external genitalia can show different degrees of female sign. The genital tract of both sexes can exist at the same time. The appearance is similar to the hypospadias combined with cryptorchidism. The sex chromatin can be positive. Can also be negative, sex chromosome 2 / 3 is XX, 1/3 is XY, urinary 17 ketosteroids can be normal, more than half of the sex chromosomes are 46XX, a few are 46XX/46XY chimera or 46XY, laparotomy can be found in vivo with testes Gonad (ovary test) of two components of ovary, case: male, 24 years old, college student, admitted to the hospital due to penile hypospadias, urethral opening at the base of the penis, penis bent, no content on the left side of the scrotum (Fig. 3), prostate Normal, monthly spermatorrhea 1 time, 24h urine 17 hydroxysteroids 2.8mg, urine 17 ketone steroids 2.3mg, sex chromatin is negative, sex chromosome is XY, surgical exploration of the right scrotum is testis, there is a mass in the pelvis, shape Like the ovary, there is a fallopian tube umbrella end, and there are fallopian tube tissues and uterine tissue (Fig. 4), which are removed. Pathological sections are confirmed by follicles and white and naive ovarian tissue. After urethroplasty, the final diagnosis is Of hermaphroditism.

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