A 3-day-old girl is brought to the emergency department by her parents due to persistent vomiting and refusal to feed. The vomiting began early in the morning and has been a greenish-yellow color. The emesis does not contain blood. The infant appears dehydrated. Her heart rate is 175/min and blood pressure is within normal limits. After initial evaluation is complete, the infant undergoes laparotomy. Findings include a normal-appearing duodenum, the absence of a large segment of jejunum and ileum, and the remainder of the distal ileum winding around a thin vascular stalk. Which of the following intrauterine processes is most likely responsible for this patient's condition?

Question

A 3-day-old girl is brought to the emergency department by her parents due to persistent vomiting and refusal to feed.  The vomiting began early in the morning and has been a greenish-yellow color.  The emesis does not contain blood.  The infant appears dehydrated.  Her heart rate is 175/min and blood pressure is within normal limits.  After initial evaluation is complete, the infant undergoes laparotomy.  Findings include a normal-appearing duodenum, the absence of a large segment of jejunum and ileum, and the remainder of the distal ileum winding around a thin vascular stalk.  Which of the following intrauterine processes is most likely responsible for this patient's condition?

Quizplus · Accepted Answer

11ec160b_3742_3604_9249_ab965b10ff4a_MD0001_00 Bilious emesis in a neonate is a sign of intestinal obstruction below the second part of the duodenum. The differential diagnosis includes midgut volvulus, which is a surgical emergency and must be excluded definitively. Other causes include intestinal stenosis and atresia. The more distal the atresia, the more likely it is to present with abdominal distension rather than bilious emesis. The absence of a segment of jejunum and ileum in this case confirms that the infant's condition is due to intestinal atresia. Intestinal atresias of the midgut (eg, jejunum, ileum, proximal colon) are the result of vascular occlusion in utero. Diminished intestinal perfusion leads to ischemia of a segment of bowel, with subsequent narrowing (stenosis) or obliteration (atresia) of the lumen. If a major vessel (eg, the superior mesenteric artery) is occluded, the area of intestinal necrosis is large. The result is a proximal segment that ends in a blind pouch; followed by an area of absent small bowel and associated dorsal mesentery; and, finally, a distal segment of ileum that assumes a spiral configuration around an ileocolic vessel. This specific pattern is known as an "apple-peel" or "Christmas tree" deformity. (Choice A) Improper rotation of the developing gut and the mesentery can lead to malrotation and subsequent midgut volvulus. The presentation of midgut volvulus (bilious emesis) is similar to intestinal atresia. However, the surgical findings in this case (atresia rather than malrotation) rule out midgut volvulus. (Choice B) Hirschsprung disease results from the failure of neural crest cells to migrate into the distal colonic wall. Without neural crest cells, submucosal and myenteric plexi do not develop and the distal colon becomes nonfunctional. Affected infants have intestinal obstruction and failure to pass stool. (Choice C) Failure of the tracheoesophageal septum to partition the foregut into the esophagus and the trachea during the 4th-5th week of gestation leads to tracheoesophageal fistula. (Choice D) Duodenal atresia occurs when the duodenal lumen fails to recanalize after endothelial proliferation during the 8th-10th week of gestation. Recanalization failure is not the cause of atresia or stenosis in the distal gut; distal atresias are due to vascular injury. Educational objective: Intestinal atresia distal to the duodenum occurs due to vascular accidents in utero. "Apple-peel" atresia occurs when the superior mesenteric artery is obstructed. The result is a blind-ending proximal jejunum; a length of absent bowel and mesentery; and, finally, a terminal ileum spiraled around an ileocolic vessel. __________ References: Apple peel small bowel. (http://www.ncbi.nlm.nih.gov/pubmed/18446163)

A 3-Day-Old Girl Is Brought to the Emergency Department by Her