No meconium

Introduction The absence of a fetus means that the fetus cannot be discharged 24 hours after birth, which is caused by a congenital anorectal malformation. Congenital rectal anal developmental malformations are very common, and there are many types, and the position of the rectal blind end and the fistula are different.

Cause

The occurrence of rectal anal malformation is the result of an obstacle in the development of the embryo, and the male and female are basically the same, only the anatomical difference. As a result of the cloaca separation process, the urogenital sinus and the anorectal sinus communicate with each other to form a high or intermediate malformation, and various anorectal hypoplasia and fistulas between the rectum and the urethra or vagina occur. The result of anal posterior movement disorder and perineal dysplasia constitutes a low position deformity, anal skin spasm, anal vestibular fistula, anal stenosis and the like.

an examination

Related inspection

Fecal trait abdomen plain film

Because it is a deformed body surface, it is easy to diagnose. In addition to clinical examination, the distance between the blind end of the rectum and the levator ani muscle plane and the anal skin must be further determined to determine the type of deformity, the location of the fistula, and the malformation to select the appropriate treatment.

(1) Inverted lateral X-ray film: called the Wangenst-een-Rice method, which requires more than 12 hours after birth to wait for the gas to reach the rectum, and the poor living ability takes longer. In the perineal anal area, the sputum is applied as a marker. The baby is inverted for 2 to 3 minutes before the film is taken, so that the flattened fetus and the intestinal tube gas are mutually converted, and the hip joint is rotated at 90°, so that the retention can fully display the P point. The angle of the center of the pubic bone, the point C (the appendix joint), and the point I (the lowest point of the ischial bone) is centered on the large trochanter of the femur, and one piece is taken during exhalation, inhalation, and crying.

Set the I line parallel to the PC line through I point, and the distance between the PC line and the PC line is the levator muscle group. The blind end of the rectum is above the PC line, and the middle line is between the second line. . Or set M point, that is, the upper 2/3 and lower 1/3 junction of the ischial tuberosity, the middle position above the M line, and the lower position below the M line.

However, it is necessary to pay attention to various influencing factors, such as insufficient inflation of the intestines, too thick stools, movement of the levator ani muscles, and deflection of the X-ray projection angle, which can affect the correctness of the position.

(B) fistula angiography: fistula angiography requires the image of the colon when the contrast agent is injected and the image of the rectal fistula when the contrast agent is discharged. Double contrast of the colorectal and urethra can show the relationship between the rectal fistula and the urethra. Vaginal angiography can show the relationship between the vagina and the rectum.

When the baby is carefully observed after the birth of the perineum, it can be found that there is no anus in the normal anus position, especially if the fetus is not discharged 24 hours after birth, it should be checked in time. If it can be found early, its clinical manifestations are different degrees of low intestinal obstruction. In cases of innocent or with small fistulas, acute complete low intestinal obstruction often occurs early in life. In cases of anorectal stenosis or with large fistulas, depending on the degree of stenosis and fistula size, defecation difficulties, constipation, fecal formation, secondary megacolon and other chronic obstructive symptoms may occur in weeks, months or even years. .

Differential diagnosis

Mainly differentiated from rectal atresia.

Rectal atresia is a certain distance between the blind end of the rectum and the anus. It is caused by the primordial anal dysplasia during the fetal period. The symptoms are more serious than the lock anal. The degree of swelling around the anus is smaller than that of the lock anus.

(A) high malformation: about 40%, more common in boys, often with fistulas, but because of the small tube, almost all have intestinal obstruction symptoms. The innervation of the pelvic muscles is often defective with axillary and upper urinary tract malformations. In this type of case, the skin is slightly sunken at the normal anal position, and the pigment is deep, but there is no anus. When the crying is noisy, the depression does not bulge outward, and there is no impact when touched with a finger. Girls are often accompanied by vaginal fistulas that open in the posterior wall of the vagina. The external genitalia is also stunted and is naive. The feces often flow out of the mouth and easily cause genital tract infections. Boys are often accompanied by urinary fistulas, which discharge gas and fetus from the urethra. Recurrent urethritis, penile head inflammation and upper urinary tract infections can occur.

(2) Middle position malformation: about 15%. The innocent blind end of the intestine is located near the cavernous muscle of the urethral bulb or near the lower part of the vagina, and the puborectalis muscle surrounds the distal rectum. In some cases, the fistula is opened in the urethral bulb, the lower vagina or the vestibule. The appearance of the anus is similar to the high deformity, and it can also be defecate from the urethra or vagina. The probe can enter the rectum through the fistula and the tip of the probe can be reached in the perineum. In the girl is more common in the rectal vestibule, because the mouth is located in the vestibular scapular fossa, also known as the scapular fossa, the pupil is larger, the baby can maintain normal bowel movement through the pupil early, can cause vaginitis or ascending infection.

(3) Low position deformity: about 40%. The position of the rectal end is lower, and more with a fistula, rarely accompanied by other deformities. Some are covered by a film at the normal anus position, and the color of the fetus is faintly visible. When the crying is noisy, the diaphragm bulges outward obviously, and sometimes the anal membrane is broken, but it is not complete and the bowel movement is difficult. In the boy with anal skin spasm, the tube is filled with feces and dark blue, the mouth is located in the perineum, or more to the scrotum, or any part of the urethra. In the girl with an anal vestibule or skin sputum, the mouth is located in the vestibule or perineum of the vagina.

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