الفهرس 
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Abstract
Relatively speaking, congenital duodenal atresia is one of the more common intestinal anomalies treated by pediatric surgeons, occurring 1 in 2500-5000 live births. In 25-40% of cases, the anomaly is encountered in an infant with trisomy 21 (Down syndrome).The definitive intervention to correct the anomaly is surgical and consists of duodenoduodenostomy in the newborn period.
Duodenal atresia represents complete obliteration of the duodenal lumen. A duodenal diaphragm (or duodenal web) is thought to represent a mild form of atresia. Duodenal stenosis (incomplete obstruction of the duodenal lumen) is discussed with duodenal atresia because the 2 disorders together represent a spectrum of similar intrauterine events.
Obstruction of the jejunum and ileum can occur as the result of jejunoileal atresia. Jejunoileal atresia is the most common intestinal atresia and the most frequent cause of neonatal intestinal obstruction. The prognosis depends on several important factors.
In many of cases, no history of maternal polyhydramnios exists because much of the swallowed amniotic fluid can be absorbed from the intestine proximal to the obstruction. This disorder, typically manifest in the 1st few days of life with feeding problems, abdominal distention, and emesis that may be bilious or fecal. The neonate may pass a small amount of meconium initially but thereafter does not pass stools.
The general diagnostic approach and preoperative management include giving nothing by mouth, placing an NGT to prevent further bowel distention or possible aspiration of vomitus, correcting fluid and electrolyte disturbances, taking a plain film x-ray, and then performing a contrast enema to delineate the anatomy.
However, the prognosis is generally good, except when a patient presented with factors, such as, low birth weight or anastomotic leakage, which prolonged hospital stays. Moreover, sepsis is the only important factor contributing to mortality.
Meconium ileus (MI) is among the most common causes of intestinal obstruction in the newborn, accounting for 9-33% of neonatal intestinal obstructions. MI is the earliest clinical manifestation of cystic fibrosis (CF) and occurs as either simple or complicated in approximately 16-20% of patients who have CF, although MI also occurs in patients who do not have CF. Clinically, CF is characterized by the triad of (1) chronic obstruction and infection of the respiratory tract, (2) exocrine pancreatic insufficiency, and (3) elevated sweat chloride levels.
A possible MI diagnosis should raise the suspicion of CF in the fetus. Antenatal diagnosis of MI can be confirmed in 2 groups. In the low-risk group, the diagnosis is suspected when routine prenatal ultrasonography reveals the sonographic appearances of MI. The high-risk group consists of all pregnancies subsequent to the birth of a child with CF. Parents of a child with CF are obligate carriers of a CF mutation.
Intestinal malrotation is a birth defect involving a malformation of the intestinal tract. Intestinal malrotation is an abnormality that occurs while a fetus is forming in its mother’s uterus.
As a fetus is growing in its mother’s uterus before birth, different organ systems are developing and maturing.
• The digestive tract starts off as a straight tube from the stomach to the rectum.
• Initially, it is located in the fetus’ abdomen, but, for a while, part of the intestine moves into the umbilical cord.
• At about the 10th week of pregnancy, the intestine leaves the umbilical cord and goes back into the abdomen.
• After returning to the abdomen, the intestine makes two turns, and is no longer a straight tube.
Malrotation occurs when the intestine does not make these turns as it should. In addition, intestinal malrotation causes the cecum (the end of the small intestine) to develop abnormally. The cecum is normally located in the lower right side of the abdomen. With malrotation, the cecum and the appendix (which is attached to the cecum) stay in the upper right side of the abdomen. Bands of tissue called Ladd’s bands form between the cecum and the intestinal wall and can create a blockage in the duodenum.
A volvulus is a problem that can occur after birth as a result of intestinal malrotation. The intestine becomes twisted, causing an intestinal blockage. This twisting can also cut off the blood flow to the intestine, and the intestine can be damaged.
Meconium plug syndrome, also termed functional immaturity of the colon, is a transient disorder of the newborn colon characterized by delayed passage (>24-48 h) of meconium and intestinal dilatation
Contrast enema demonstrates the retained meconium as a filling defect or plug that produces a double-contrast effect. Small left colon syndrome is a subset of meconium plug syndrome in which an enema demonstrates an apparent transition zone between the dilated and the normal-to-decreased caliber distal colon at the splenic flexure.
Hirschsprung disease is a developmental disorder of the enteric nervous system and is characterized by an absence of ganglion cells in the distal colon resulting in a functional obstruction.
Although this condition was described by Ruysch in 1691 and popularized by Hirschsprung, the pathophysiology was not clearly determined until the middle of the 20th century, when the aganglionosis of the distal intestine is described as the cause of obstruction. In 1949, Swenson described the first consistent definitive procedure for Hirschsprung disease, rectosigmoidectomy with coloanal anastomosis. Since then, other operations have been described, including the Duhamel and Soave techniques. More recently, advances in surgical technique, including minimally invasive procedures, and earlier diagnosis have resulted in decreased morbidity and mortality for patients with Hirschsprung disease.
Most cases of Hirschsprung disease are now diagnosed in the newborn period. Hirschsprung disease should be considered in any newborn who fails to pass meconium within 24-48 hours after birth. Although contrast enema is useful in establishing the diagnosis, full-thickness rectal biopsy remains the criterion standard. Once the diagnosis is confirmed, the basic treatment is to remove the poorly functioning aganglionic bowel and to create an anastomosis to the distal rectum with the healthy innervated bowel (with or without an initial diversion).
An anorectal malformation is a condition in which the rectum fails to separate properly during development and does not migrate into its proper position on the perineum. The anus and rectum lie in front of their normal location and are not located properly in the sphincter muscles of the pelvis. Anorectal malformations occur as a spectrum of abnormalities that ranges from very mild conditions in which the anus is situated only a few millimeters in front of its normal location, to severe anomalies with no visible anus. In the more severe abnormalities, there may be an abnormal emptying of rectum into the genitourinary tract, and associated malformations of the spine, genitalia, and kidneys.
Anorectal malformations occur in both boys and girls. The diagnosis of an anorectal malformation can usually be made by inspection. When the baby is examined, the anus is absent or abnormally positioned. Ultrasound and x-ray tests may be used to help in the diagnosis. Additional tests will be obtained to look for associated abnormalities. Spine x-rays, kidney and spinal cord ultrasound, and occasionally echocardiography are all routine tests obtained in patients with anorectal malformations.
The nature and severity of the anorectal malformation, as well as the presence of any associated conditions will determine the surgical treatment that is required. Some patients may be treated with a single operation as a newborn, while others will require operations in several stages. For patients with relatively minor abnormalities, a small procedure such as a cut back anoplasty may be all that is required prior to going home. For other patients, initial treatment consists of a colostomy and reconstruction is performed at a later date. A second operation is performed that separates the abnormal communication with the genito-urinary tract, and properly relocates the rectum within the sphincter muscles in the pelvis. Depending on the type of abnormality present, children may have this operation performed utilizing minimally invasive surgical techniques. Alternatively, a PSARP (posterior saggital anorectoplasty) procedure may be performed. Several months after definitive surgery, the colostomy is taken down, re-establishing gastrointestinal tract continuity.
Following reconstruction, patients born with anorectal malformations must be followed frequently by their pediatric surgeons. For the more severe abnormalities, long-term continence issues are the major reasons for follow-up, while in the more mild conditions, patients and their families must work to insure that worsening constipation does not lead to poor continence. Many patients must be managed with bowel program designed to promote regular evacuations of the rectum to avoid ongoing soiling from chronic fecal retention. With attentive management, and rigorous compliance with prescribed regimens, most patients achieve social continence. Many patients will have normal continence.