Volume 5, Case 19
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
This is a 16-month old male who presents to the emergency department with a two day history of fussiness, abdominal pain, and vomiting. His mother attempted to cure his condition by administering herbal teas and herbal enemas. He became poorly responsive which promoted his mother to bring him to the E.D. He has felt warm, but his temperature was not measured at home.
Exam: T 37.4 (rectal), P195, R40, BP 99/54, Oxygen saturation 98% in room air. He is drowsy but arousable. Eyes somewhat sunken. TM's normal. Oral mucosa sticky. Lips dry. Neck supple. Heart regular, tachycardic, without murmurs. Lungs clear. Abdomen shows moderate distention with intermittent hypoactive bowel sounds. There is diffuse tenderness. No masses are appreciated. No hernias. Testes are normal.
IV fluid hydration is started. Blood studies are drawn. A nasogastric tube is inserted. Greenish fluid returns. Abdominal radiographs are obtained.
View abdominal radiographs.
[Supine view]
[Decubitus view]
The decubitus view is a left lateral decubitus film (left side down). The flat view is taken in the supine position. There is a nasogastric tube with its tip in the stomach. There is no evidence of free air.
Review Case 18 in Volume 3 (Test Your Skill In Distinguishing Bowel Obstruction From Ileus) to review the radiographic findings consistent with a bowel obstruction. Assessing these criteria in this set of radiographs follows:
a) Gas distribution: Gas is distributed throughout the abdomen except for the right lower quadrant on the supine view.
b) Bowel distention: This is best assessed by the smoothness of the bowel walls rather than measuring the diameter of the bowel lumen. In a bowel obstruction, the bowel acquires a smooth appearance resembling large hoses or sausages. As the bowel distends, it loses its normal plicated/haustrated appearance and the bowel walls become smooth. In this case, the bowel is distended (smooth and sausage-like).
c) Air/Fluid levels: There are several large air fluid levels seen on the lateral decubitus view. While small air/fluid levels are most often indicative of an ileus, large air fluid levels with J-shaped (candy cane or hairpin turns) loops are more suggestive of a bowel obstruction.
d) Orderliness: This is best appreciated on the flat (supine) view. In this case, the gas pattern is orderly rather than disorderly. In other words, it resembles a bag of sausages more so than a bag of popcorn. The orderly (bag of sausages) appearance is more indicative of a bowel obstruction.
Both the flat and left lateral decubitus films show considerable bowel dilatation. There are large air/fluid levels on the decubitus view. This is consistent with a distal mechanical bowel obstruction. In addition to the findings of a bowel obstruction, there is granular radioopaque material in the bowel (mostly colon).
Upon obtaining further history inquiring about his diet, he has a history of eating sand, dirt, and glass. It is likely that the granular material in the bowel is probably a mixture of sand and other debris. How does this affect our treatment approach?
While barium studies may be useful to further image his bowel, at this point, he is felt to have an acute bowel obstruction. Clinically, his degree of abdominal distention and tenderness is felt to necessitate a laparotomy. What about the possibility of the sand and other debris obstructing the bowel?
At this point, the differential should include, intussusception, appendicitis, and midgut volvulus. In general, causes of bowel obstruction include conditions that start with AIM:
At laparotomy, he is found to have a midgut volvulus with necrotic bowel caused by a tight band around a Meckel's diverticulum. The necrotic bowel is resected and viable bowel is reanastomosed. There is no evidence of bowel perforation. The radioopaque sand and other debris seen on the abdominal radiographs were "red herrings". A further imaging work-up would have only delayed surgical intervention.
Discussion
Two percent of the population are born with a Meckel's diverticulum (one in fifty !!). It is located 50 to 75 cm proximal to the terminal ileum. Meckel's diverticulum is most often asymptomatic as only 2% of those with Meckel's diverticulum manifest clinical problems.
The Meckel's rule of 2's:
a) 2% of the population are born with a Meckel's.
b) Only 2% of those with a Meckel's manifest clinical problems.
c) Usually located 2 feet proximal to the terminal ileum and the diverticulum is usually 2 inches long.
d) Symptoms commonly manifest at age 2 years.
The most common presentation of a Meckel's diverticulum is painless intestinal bleeding. The Meckel's diverticulum contains ectopic acid-secreting gastric mucosa. The epithelium in the Meckel's diverticulum may ulcerate and bleed. Slow bleeding may present with signs of iron deficiency anemia and occult stool blood loss or melena. More rapid bleeding may present with hematochezia. An ulcerating Meckel's may also perforate leading to peritonitis and an acute abdomen.
Less commonly, a Meckel's diverticulum may present as a bowel obstruction or with abdominal pain. The base of the Meckel's diverticulum may form a leading edge for an ileal intussusception. If the Meckel's diverticulum is still attached to the anterior abdominal wall, this may predispose one to a volvulus. Both of these presentations will present with signs and symptoms of a bowel obstruction.
A Meckel's diverticulum may become inflamed. This results in abdominal pain with a clinical picture similar to that of appendicitis (see Case 9 of Volume 4, Periumbilical Abdominal Pain). If a Meckel's diverticulitis perforates, it will lead to peritonitis. One mechanism of Meckel's diverticulitis is a volvulus of the diverticulum itself leading to ischemic necrosis.
Meckel's diverticulum can be diagnosed on scintigraphy. The so-called Meckel's scan is based on an isotope labeled compound that localizes in gastric mucosa. This isotope normally accumulates in the stomach and bladder. Additionally, upper GI peristalsis carries the isotope into the duodenum and proximal jejunum. A positive study will demonstrate a hot spot in the lower abdomen, usually on the right. The pre-treatment administration of pentagastrin and cimetadine may improve the accuracy of the scan.
Barium studies will sometimes identify a Meckel's diverticulum. However, upper GI series and barium enemas cannot be used to reliably rule out a Meckel's diverticulum.
Meckel's diverticulum is often diagnosed at laparotomy when surgical intervention is indicated, such as in a bowel obstruction refractory to conservative measures, a refractory intussusception, a suspected volvulus, a rule-out appendicitis or an acute abdomen.
Reference
Goglia RP. Meckel's Diverticulum. In: Ashcraft KW, Holder TM (eds). Pediatric Surgery, second edition. W.B. Saunders, Philadelphia, 1993, pp. 435-439.