ll. Females like males can have a rectoperineal fistula and for them an anoplasty in the newborn period should be performed. Like in males, less than 5% of female babies have no clinical evidence of the location of the rectum after 24 hours. They may have imperforate anus with no fistula. A cross-table lateral x-ray should be performed, and will help determine the need for a colostomy.
As discussed previously, the surgeon must decide in the newborn period whether the child requires fecal diversion with a colostomy, or can undergo a primary repair procedure.
The preferred colostomy is a descending colostomy, i.e. made from the descending portion of the colon located in the lower-left quadrant of the abdomen, with separated stomas . The proximal stoma is connected to the upper gastrointestinal tract and drains stool. The distal stoma, also called a mucous fistula, is connected to the rectum and will drain small amounts of mucus material. The advantages of this type of colostomy are many: 1) it defunctionalizes only a small portion of distal colon, 2) in cases of large rectourinary fistulae in which the patient passes urine into the bowel, the urine comes out easily through the mucous fistula, avoiding problems of hyperchloremic acidosis due to urine absorption. Urinary tract infections are also avoided, 3) it is relatively easy to wash and clean the part of the colon distal to the colostomy, 4) distal colostograms are easy to perform, 5) the sigmoid loop is kept distal to the colostomy which provides enough length to reach the perineum during the definitive pull-through procedure, 6) the separated stomas prevent spillage of stool from proximal to distal bowel, which avoids impacted distal stool and urinary tract infections, 7) there is a low incidence of prolapse with this technique. Proximal stoma prolapse in a normally rotated colon should not happen with this technique because the colon is well fixed to the retroperitoneum just before the colostomy rises to the skin level. The distal stoma may prolapse because it is in a mobile portion of the colon. To avoid this, the distal stoma must be made intentionally small, as it will be used only for irrigations and radiologic studies. When performing the colostomy in the newborn, the distal bowel should be irrigated to remove all of the meconium. This prevents formation of a megasigmoid, which may be responsible for the future development of constipation.
Several pitfalls exist with regard to the creation of the colostomy. 1) If the colostomy is placed too distal, it will interfere with the pull-through. 2) During attempts to perform a transverse colostomy, cases of inadvertent sigmoid colostomy placed in the right upper quadrant have occurred. Anchoring of the sigmoid in the right upper quadrant would interfere with the pull-through procedure. 3) A loop colostomy does not completely divert the stool and allows for distal stool impaction and urinary tract infections. 4) Transverse colostomies produce megarectum .
• Posterior sagittal approach
◦ Anorectal repair
The repair of an anorectal malformation requires a meticulous and delicate technique and a surgeon with experience in the management of these defects. The posterior sagittal approach is an ideal method of defining and repairing anorectal anomalies. If the baby growing well, the repair can be performed at 1–2 months of age. Detailed surgical procedure can be found in the following references: [1, 2, 5, 6].
Ninety percent of male patients can be approached with a posterior sagittal approach alone, while 10% require an abdominal component (with laparotomy or laparoscopically) to mobilize a very high rectum. All female malformations, with the exception of about 30% of cloacas can be repaired with this approach. In 30% of cloacas, the rectum or vagina is so high as to require an abdominal approach as well .
◦ Rectobladder neck fistula
In the rare case of a true supralevator malformation (rectobladder neck fistula), the operation involves both a posterior sagittal incision and an abdominal component, which can be done with lap