t 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 laparoscopy or laparotomy (Figure 6).
◦ Imperforate anus without fistula
In patients with imperforate anus without fistula, the same meticulous dissection is required to separate the distal rectum from the urinary tract as in patient with rectourinary fistulae because the rectum and urethra still share a common wall.
◦ Rectovestibular fistula
In cases of rectovestibular fistula, the posterior sagittal incision can be shorter than in male patients with rectourethral fistulae. Often the entire levator mechanism needs not be divided and only the external sphincter, muscle complex, and part of the lower portion of the levator mechanism need to be divided. The rectum and posterior vagina share a common wall, and it is this separation that is the most difficult part of the operation. Once the rectum is completely mobilized, a perineal body is constructed, and the rectum is placed within the limits of the sphincter mechanism .
◦ Rectal atresia
A very rare malformation, rectal atresia, occurs in 1% of cases. The anal canal is normal and externally the anus appear normal. However, there is a blockage 1–2 cm from the anal skin, usually found when the nurse tries to pass a thermometer. These babies should undergo colostomy at birth, and then their definitive repair involves a posterior sagittal approach and an end-to-end anastomosis between the upper rectal pouch and the anal canal.
◦ Persistent cloacas
The repair of persistent cloacas represents a serious technical challenge that should be performed in specialized centers by pediatric surgeons dedicated to the care of these complicated patients . This malformation represents a wide spectrum of defects by itself. The defect involves fusion of the rectum, vagina, and urethra together to form a common channel (Figure 7). The length of this common channel can range from 1 to 10 cm. The rectum and vagina share a common wall and the vagina and urinary tract likewise have a common wall. The goals of surgical treatment are to achieve bowel control, urinary control, and normal sexual 