Teaching Case

A three-week-old male child was referred to the Department of Pediatric Surgery in a markedly reduced condition because of repeated vomiting several times in the last few hours and recurrent diarrhea alternating with constipation since birth.

A three-week-old male child was referred to the Department of Pediatric Surgery in a markedly reduced condition because of reported vomiting several times in the last few hours and recurrent diarrhea alternating with constipation since birth. Postprandial often a remarkable rumbling abdominal noise was heard by the parents. After emesis, which was sometimes bilestained, he recovered spontaneously. Physical examination showed a distension of the upper abdomen. The laboratory was normal except for mild elevation of the white blood cell count. Plain radiography of the abdomen revealed moderately dilated loops of small bowel in the left upper abdomen. Ultrasound showed little free fluid in the abdomen. 20 ml of water-soluble nonionic iodinated contrast medium were administered through a nasogastric tube into the small bowel. It revealed a cluster of jejunum-loops in the left upper quadrant of the abdomen (Figure. 1A and 1B). The stomach was displaced superiorly (Figure 1A), the duodenum showed retropulsive peristalsis.

The findings suggested a left paraduodenal hernia to be the cause of the intestinal obstruction. This diagnosis was confirmed at surgery. The trapped small bowel loops were twisted in the hernia sac for 180° and a mild venous and lymphatic congestion due to beginning strangulation was seen. The trapped jejunum was released and the orifice entrance to the hernia was closed. No resection of bowel segments was necessary. The patient’s post-operative course was unremarkable. Paraduodenal hernia, also known as mesocolic hernia, results from congenital variations in peritoneal fixation and vascular folds and from the embryologic rotation of the midgut [1]. Despite their congenital nature, parduodenal hernias usually become symptomatic in adults with the average age 38,5 years and occur more frequently on the left side [1-3]. Small intestine loops herniate through the paraduodenal fossa (fossa of Landzert), extending into the descending mesocolon and left portion of the transverse mesocolon [4]. The free edge of the hernia contains the inferior mesenteric vein and the left ascending colic artery [3]. In small hernia often only a few loops get trapped and resolve spontaneously, causing intermittent postprandial pain and vomiting [1]. Internal hernia may cause intestinal bleeding and perhaps in some cases lead to a sudden infant death [5]. The preoperative differential diagnosis relies only on radiological imaging [1]. Left paraduodenal hernias should be differentiated from intestinal atresia or stenosis, a midgut volvulus or compression by aberrant peritoneal bands (Ladd´s bands) due to malrotation. Generally, examinations should be performed during a symptomatic period not to miss an intermittent herniation. Plain radiograph helps to exclude a perforation, an abdominal mass and calcifications. Upper gastrointestinal/small bowel follow-through studies reveal a cluster of jejunal loops in the left upper quadrant lateral to the duodenum in a. p. view. In lateral view trapped proximal jejunal loops may impress the posterior wall of the stomach, the duodenojejunal junction may be displaced medially and anteriorly. To our knowledge, the using of a nasogastric tube for a small bowel follow-through examination in newborns has not been reported yet. In our case, after administration of the contrast agent directly into the duodenum, the investigation was performed within some minutes. We conclude that the direct visualization of proximal small bowel via the tube was helpful for the diagnosis. With more extensive invagination into the transverse mesocolon, the distal transverse colon may be depressed. Larger left parduodenal hernias present as ovoid mass of intestinal loops. In erect position the lower border of the intestine is convex downward with most small bowel loops inside [1,2]. The findings in CT involve a medially displaced duodenojejunal junction by the herniated jejunal loops between the stomach and body of pancreas and dilatation and air fluid levels in the trapped loops [2,4,5]. However a contrast study of the small bowel is easy to perform and children need not to be anaesthetized to avoid motion artifacts like in CT or MRI. As there are no reliable and typical clinical symptoms of paraduodenal hernias, and cases in young children are rare, a fast and accurate radiological diagnosis is necessary, not to miss the right time for an surgical intervention.