Case # 4: Perforated Meckel diverticulum
A 12-year-old male was transferred from an outside facility to our hospital with a suspected diagnosis of ruptured appendicitis. Prior to transport, he received broad-spectrum IV antibiotics and IV narcotics. He initially presented to the transferring facility with sudden, severe periumbilical pain. He was previously in good health without any nausea, vomiting, or change in bowel habits.
Vital signs were within normal limits, and he appeared comfortable in a seated position, although he stated that lying supine worsened the pain. He had been given sufficient analgesia. Abdominal palpation revealed some rigidity, guarding, and tenderness in the periumbilical area and right lower quadrant. Bowel sounds were present but diminished in all four quadrants. Urinalysis revealed trace amounts of blood.
A US obtained at the transferring facility revealed free fluid in the abdomen and pelvis with the appendix not visualized. An abdominal and pelvic CT obtained at our facility confirmed free fluid and air in the pelvis and also revealed a 1.8 x 1.0 cm fluid-filled structure with surrounding inflammatory changes in the patient’s midline. At the time of diagnostic laparotomy the cecum was found to be adhered to the side wall of the pelvis, and the appendix was found to be intact and without any signs of inflammation.
The terminal ileum was identified and traced back in retrograde fashion, where a severely inflamed and perforated Meckel diverticulum was found. At that point, the surgery was converted to an open laparotomy; the Meckel diverticulum and appendix were removed. The boy had an uneventful recovery and was discharged on postoperative day 3.
Meckel diverticulum occurs in approximately 2% of the population and is the congenital result of the omphalomesenteric duct failing to obliterate completely during development.12 Meckel diverticuli are commonly asymptomatic but younger patients often present with painless rectal bleeding and anemia. In 4% to 16% of cases, however, a Meckel diverticulum may lead to severe complications, such as hemorrhage, intussusception, inflammation, and perforation, although perforation is extremely rare.13,14
Diagnosis of a Meckel diverticulum with resultant complication can be difficult, because symptoms tend to be nonspecific and often can mimic appendicitis. Imaging may not lead to diagnosis: US is only useful if the diverticulum is complicated by intussusception and CT scan tends to reveal normal bowel in the absence of complication.
The standard diagnostic test for a Meckel diverticulum is the technetium-99m pertechnetate scan, but it yields higher false-negative rates in the absence of bleeding and is dependent on the presence of ectopic gastric mucosa in the diverticulum. Often, definitive diagnosis is not made until the patient is in the operating room.
Case #5: Intussusception
An 8-year-old male presented with 3 days of severe, intermittent, stabbing, progressive abdominal pain. The pain was right-sided, periumbilical, nonradiating, and preceded by several episodes of brown, nonbloody diarrhea. He had been healthy previously and he denied nausea, vomiting, dysuria, melena, or hematochezia. Vital signs were within normal limits, and the child was in only mild distress. The abdomen was soft and nondistended, and tenderness was appreciated in the right lower quadrant. Obturator, psoas, Murphy sign, and Rovsing signs were negative. Rectal exam was unremarkable.
An abdominal and pelvic CT showed the classic “target sign” of intussusception (Figure 4), and an exploratory laparotomy was emergently performed. The intussusception was reduced, and a 1.5 x 1.5 x 1.5 cm Meckel diverticulum was discovered to be the lead point. It was excised to prevent further complications or recurrence.15 Recovery was uneventful.
Figure 4. Classic doughnut sign of intussusception as seen on US.
Intussusception is one of the most common surgical abdominal emergencies in children, mostly affecting children between age 8 weeks and age 5 years, but the condition can occur in older pediatric populations and adults as well.16Typical presentation is sudden onset of severe, intermittent abdominal pain in a previously healthy child, often described as a child having episodic periods of curling into a ball with intense pain and then returning to a pain-free state and appearing well. Vomiting and hematochezia may be seen as well, with the hematochezia often referred to in this condition as “currant jelly stool” because of the appearance of the bloody, mucus-like bowel movement.17 Intussusception is often mistaken for gastroenteritis, and in fact, is often preceded by gastroenteritis when it occurs in younger children, with the proposed pathophysiology involving the inflammation of lymphatic tissue causing the bowel to intussuscept. The majority of cases are idiopathic, but up to one-quarter of cases can be found to have a lead point, such as a Meckel diverticulum (as in our patient) or inflamed lymph nodes in viral illnesses. Inability to reduce the intussusception, or a transition point in the right lower abdominal quadrant, should increase the suspicion of the presence of Meckel diverticulum. The presentation on imaging is classic, seen either on CT or now more commonly using US, with the target sign caused by different densities of tissue layers that have become apposed to each other by means of the telescoping of the bowel. Enema is successful in reducing intussusception in 90% of cases, although recurrence is not uncommon.18 Surgery is needed in cases of unsuccessful reduction, if complications occur, or if a lead point is identified.