DDx
Diagnostic Considerations
The usual context of neonatal intestinal obstruction is an infant who is not feeding normally. The answers to a few questions, including the following, will suggest the correct diagnosis:
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Is the baby vomiting? What color is the emesis?
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Was an orogastric tube passed; if so, how much fluid was drained from the stomach? What was its color?
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Has the baby passed meconium and/or transitional stools?
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Is the baby's abdomen flat or distended? Is it soft or tender? Is there a palpable mass?
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Is the baby septic? Are there other signs of ilness: irritability, temperature instability, apnea/bradycardia episodes?
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Is examination of the baby's perineum normal? Is the anus patent?
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Were plain radiographs obtained? Is the gas pattern normal?
The cause of bilious emesis includes sepsis, accompanied by ileus, or necrotizing enterocolitis. However, these conditions usually occur in babies who previously had demonstrated continuity of the gastrointestinal tract.
In a baby who previously tolerated feedings, midgut volvulus must always be considered in the differential diagnosis of bilious vomiting.
Babies with distal small bowel obstruction present with abdominal distention, delayed passage of meconium, and absent transitional stools (meconium mixed digested milk). Plain radiographs are usually diagnostic, demonstrating multiple dilated loops of small bowel and no air in the colon. A Gastrografin (diatrizoate) enema is diagnostic; it may also be therapeutic if the baby has meconium ileus or meconium plug syndrome.
Associated conditions
Conditions that may be associated with neonatal intestinal obstruction include the following:
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Infants with gastroschisis may have intestinal atresia.
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Malrotation is associated with abdominal wall defects and congenital diaphragmatic hernia.
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Tracheoesophageal fistulas are typically associated with esophageal atresia, but isolated fistulas (H type) also occur.
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A Meckel diverticulum or pancreatic rest (ectopic pancreatic tissue) may serve as a lead point in intussusception.
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Occasionally, the omphalomesenteric duct forms a band between the ileum and the umbilcus that may entrap a loop of intestine.
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Short bowel syndrome (intestinal failure) may be associated with gastroschisis, intestinal atresia, and necrotizing enterocolitis.
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The massively dilated ascending colon should be resected, leaving a small cuff of cecum that is fashioned into an ostomy. Later, the ostomy may be anastomosed to the distal colon. See the following image.
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Intestinal obstruction in the newborn. Colonic atresia. The hugely dilated colon will never function satisfactorily; therefore, it is resected, leaving a cuff of cecum to preserve the ileocecal valve.
Intestinal perforation may be associated with the following:
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Antenatally: Meconium peritonitis is meconium ileus with a perforation leading to extrusion of meconium into the peritoneal cavity. Usually, there are dense adhesions that make identification of the proximal and distal ends of the intestine difficult.
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Postnatally: In micro preemies (< 800 g [1 lb, 12 oz] [20] ) with intestinal perforation, the perforated segment may have localized (aneurysmal) dilatation proximal to bowel whose caliber is tiny and whose lumen is filled (obstructed) with inspissated stool (see the image below).
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Intestinal obstruction in the newborn. Photograph of neonatal intestinal perforation. Note the aneurysmal dilatation of the (perforated) intestine proximal to the obstructed (by inspissated stool) distal ileum.
Developmental immaturity (infants < 26 weeks' gestational age) is a consideration in babies with intestinal obstruction, such as the following:
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Underdeveloped musculature and poor peristalsis lead to bacterial overgrowth and a setting of immunologic immaturity; this may result in necrotizing enterocolitis.
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Small left colon syndrome is a benign condition that occurs in infants of diabetic mothers. It is self-limited and presumably developmental; it may simulate Hirschsprung disease.
Sample diagnostic algorithm
An algorithm for the diagnosis of neonatal intestinal obstruction is depicted in the image below.
Intestinal obstruction in the newborn. This diagram is a sample algorithm for the diagnosis of neonatal intestinal obstruction.
Media Gallery
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Intestinal obstruction in the newborn. Malrotation/volvulus. Note the spiral twist and the partial obstruction.
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Intestinal obstruction in the newborn. Malrotation with volvulus of the proximal small intestine coiled around the superior mesenteric vessels.
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Intestinal obstruction in the newborn. Partial duodenal obstruction: duodenal stenosis or malrotation/volvulus? Note the "double bubble" sign and narrowing of the second portion of the duodenum; however, the duodenum does cross the midline and it is not twisted.
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Intestinal obstruction in the newborn. Jejunal atresia. Note the sharp transition between the proximal dilated jejunum and the distal unused intestine at the point of the atresia.
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Intestinal obstruction in the newborn. Jejunal atresia. Ischemic compromise of the proximal segment is noted.
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Intestinal obstruction in the newborn. Meconium plug syndrome. Contrast enema shows a dilated colon proximal to the meconium plug. If the enema elicits an evacuation, the obstruction may be relieved.
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Intestinal obstruction in the newborn. Baby with a high imperforate anus; note the indistinct perineum ("rocker bottom"). Compare this photograph with the low imperforate anus photograph in the section "Surgical Relief of Obstruction," in which "pearls" of meconium along the scrotal raphe can be seen.
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Intestinal obstruction in the newborn. This diagram is a sample algorithm for the diagnosis of neonatal intestinal obstruction.
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Intestinal obstruction in the newborn. Operative photograph of hypertrophic pyloric stenosis. The pylorus is thickened and elongated.
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Intestinal obstruction in the newborn. Operative photograph of jejunal atresia with a mesenteric gap and discontinuous bowel segments.
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Intestinal obstruction in the newborn. Meconium ileus. Intraluminal intestinal obstruction from thick, tenacious meconium.
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Intestinal obstruction in the newborn. Colonic atresia. The hugely dilated colon will never function satisfactorily; therefore, it is resected, leaving a cuff of cecum to preserve the ileocecal valve.
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Intestinal obstruction in the newborn. Operative photograph of midgut volvulus. Note the transverse orientation of the colon (look for the appendix).
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Intestinal obstruction in the newborn. Omphalomesenteric duct (Meckel diverticulum) attached to the umbilicus.
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Intestinal obstruction in the newborn. Colon pull-through for Hirschsprung disease.
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Intestinal obstruction in the newborn. Midgut volvulus. Necrosis of the midgut is the the most feared complication of malrotation/volvulus.
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Intestinal obstruction in the newborn. Malrotation volvulus. Note the partial duodenal obstruction. The distal duodenum does not cross the midline (over the vertebral column) and the "curly Q" twist.
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Intestinal obstruction in the newborn. Gastrografin enema. Note the tiny, unused colon and the dilated (by swallowed air) proximal, obstructed intestine.
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Intestinal obstruction in the newborn. Midgut volvulus. The bowel is eviscerated and the entire midgut is twisted counterclockwise, effecting reduction of the volvulus.
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Intestinal obstruction in the newborn. The midgut volvulus is reduced.
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Intestinal obstruction in the newborn. Photograph of neonatal intestinal perforation. Note the aneurysmal dilatation of the (perforated) intestine proximal to the obstructed (by inspissated stool) distal ileum.
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Intestinal obstruction in the newborn. The contrast enema in a baby with Hirschsprung disease; the rectum is small and the sigmoid colon is dilated.
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Intestinal obstruction in the newborn. Operative photograph showing dilatation of the sigmoid colon and a small caliber rectum.
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Intestinal obstruction in the newborn. When the proximal mesentery is destroyed in jejunal atresia, the ileum may derive its blood supply from the ileocolic vessels and wraps around these vessels, creating the appearance of a "Christmas tree" or "apple peel."
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Intestinal obstruction in the newborn. Operative photograph showing proximal esophageal atresia and distal tracheoesophageal fistula.
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Intestinal obstruction in the newborn. Contrast enema in a baby with a small left colon and meconium plug syndrome.
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Intestinal obstruction in the newborn. Upright radiograph in a patient with complete intestinal obstruction. Note the air-fluid levels and absence of air in the colon.
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Intestinal obstruction in the newborn. Jejunal obstruction caused by a mucosal web.
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Intestinal obstruction in the newborn. Multiple atresias have a"string of sausages" appearance.
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Intestinal obstruction in the newborn. In babies with meconium ileus, the contrast enema shows an unused microcolon.
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Intestinal obstruction in the newborn. Operative photograph of jejunoileal atresia. The bowel is obstructed but in continuity.
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Intestinal obstruction in the newborn. Operative photograph of meconium ileus. The dilated, meconium-laden loop of intestine may be resected and an anastomosis performed.
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Intestinal obstruction in the newborn. Pull-through procedure for Hirschsprung disease. Note the biopsy site in the dilated bowel.
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Intestinal obstruction in the newborn. The contrast enema shows an unused microcolon in babies with meconium ileus.
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Intestinal obstruction in the newborn. Pyloromyotomy: carefully cutting and spreading apart the hypertrophied muscle layer without penetrating the mucosa.
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Intestinal obstruction in the newborn. Mother and daughter both had pyloric stenosis. Pyloric stenosis is more common in males, but if the mother had pyloric stenosis, her offspring are more likely to be affected than if the father had it. Pyloric stenosis cases occur in clusters, indicating an environmental trigger, but there is most likely a complicated interaction of heredity and environment.
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Intestinal obstruction in the newborn. An enteric duplication may cause twisting (volvulus) of a loop of intestine.
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Intestinal obstruction in the newborn. Volvulus of a loop of intestine. The intestine is obstructed at both ends, creating a "closed loop."
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Intestinal obstruction in the newborn. Initial radiograph during hydrostatic reduction of intussusception.
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Intestinal obstruction in the newborn. Radiograph when hydrostatic reduction is almost complete.
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Intestinal obstruction in the newborn. Operative photograph of intussusception.
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Intestinal obstruction in the newborn. A baby with esophageal atresia and tracheoesophageal fistula, who has right upper lobe atelectasis and pneumonia. Note the abdominal distention prior to gastrostomy tube placement, and resolution of the distention and atelectasis after placement of the gastrostomy tube.
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Intestinal obstruction in the newborn. Operative photograph of midgut volvulus. Note the transverse orientation of the colon (look for the appendix).
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Intestinal obstruction in the newborn. Baby with an incarcerated inguinal hernia causing intestinal obstruction. The viability of the testicle is also at risk.
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Intestinal obstruction in the newborn. Operative photograph of midgut volvulus, after its reduction by rotating the entire midgut in a counter-clockwise direction. Next, adhesions between the duodenum and the colon will be divided, exposing the superior mesenteric vessels.
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Intestinal obstruction in the newborn. Operative photograph of malrotation/volvulus diagnosed too late to save the midgut, which is gangrenous.
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Intestinal obstruction in the newborn. A stricture of the small intestine, following necrotizing enterocolitis, causing intestinal obstruction.
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Intestinal obstruction in the newborn. In a baby with jejunal atresia and extensive loss of the distal small bowel, the bulbous, dilated proximal jejunum may be narrowed and lengthened utilizing the STEP (serial transverse enteroplasty) procedure.
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Intestinal obstruction in the newborn. Anastomosis between the dilated proximal duodenum (left) and the smaller caliber distal duodenum.
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Intestinal obstruction in the newborn. Baby with a low imperforate anus. Note the "pearls" of meconium along the scrotal raphe. Low imperforate anus is amenable to repair during the neonatal period.
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Intestinal obstruction in the newborn. The obstructed proximal jejunum is dilated, bulbous; and its motility (peristalsis) is poor. If the baby has an adequate length of distal intestine, this segment is resected; however, if there is limited distal intestine, the STEP (serial transverse enteroplasty) procedure may convert this short dilated segment to a longer, narrower segment.
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