Meckel diverticulum is a congenital anomaly of the small intestine that can present with various clinical manifestations, including rectal bleeding and obstruction. Recognizing the characteristic features and understanding the differential diagnosis is crucial in managing patients with lower gastrointestinal bleeding. This episode will help you recognize and diagnose this surgical condition that you probably remember because the “rule of twos.”

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References

Dixon P & Nolan D. The Diagnosis of Meckel’s Diverticulum: A Continuing Challenge. Clin Radiol. 1987;38(6):615-9

Ghahremani G. Radiology of Meckel’s Diverticulum. Crit Rev Diagn Imaging. 1986;26(1):1-43

Weerakkody Y, Ranchod A, Yap J, et al. Meckel diverticulum. Reference article, Radiopaedia.org (Accessed on 26 Oct 2023) https://doi.org/10.53347/rID-17174

Sagar J, Kumar V, Shah DK. Meckel’s diverticulum: a systematic review. J R Soc Med. 2006 Oct;99(10):501-5.

An J, Zabbo CP. Meckel Diverticulum. [Updated 2023 Jan 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499960/#

Transcript

Note: This transcript was partially completed with the use of the Descript AI

Welcome to PEMCurrents: The Pediatric Emergency Medicine Podcast. As always, I’m your host, Brad Sobolewski. Your time is valuable and so is mine. And that’s why I release these brief, succinct episodes focused on a single clinical topic, get you in, get you out, teach you something. Today I’m going to talk about Meckel diverticulum. If you haven’t seen it clinically, you have seen it on a test and it is absolutely something that you should be thinking about when you see a patient with bloody stools in the emergency department.

So Meckel diverticulum is a congenital abnormality of the small intestine and it’s the most common cause of significant lower GI bleeding in children. It arises from an incomplete involution of the vitelline duct during embryonic development. You didn’t think I’d say that during this podcast.

Typically occurring during the seventh week of gestation. It’s characterized by a blind ending true diverticulum, a pouch, that contains all of the layers typically found in the ileum. So especially relevant to board exams, Meckel diverticulum follows the rule of twos. So it affects approximately 2 percent of the population.

It’s located about two feet from the ileocecal valve. It’s usually about two inches long. Only about 2 percent of cases actually become symptomatic. It is most commonly diagnosed by the age of two years, with 45 percent of symptomatic cases occurring in this age group. It is two times as common in boys, and there are two types of epithelium found in the meckle diverticulum, gastric and pancreatic.

So the clinical presentation of Meckel can vary depending on the complications that arise. The most common presentation in children Under the age of five years is rectal bleeding, which may be intermittent or just massive, but the bleeding is usually painless. Other complications include obstruction due to intussusception or volvulus, which can lead to bowel ischemia or shock.

Diverticulitis and umbilical fistula can also occur, but that might typically be seen later in life. In approximately a third of cases, Meckel diverticulum may perforate, and traumatic rupture of one could actually occur following blunt trauma. Let’s move briefly into the differential diagnosis of GI bleeding in children.

So, upper GI bleeding is typically not bright red. Now you could have a briskly bleeding ulcer and a liver transplant patient, but that’s not something we typically see in pediatrics. So generally lower GI bleeding is bright red, hematochezia, whereas the upper GI bleeding is maroon or dark black, diverticular disease.

which is rare in children, could cause bright red bleeding. A vascular ectasia or angio dysplasia, which is really hard to diagnose unless you’re an endoscopist. You could have bright red blood from inflammatory bowel disease, infectious colitis, mesenteric ischemia or ischemic colitis, colorectal cancer or polyps, hemorrhoids, both internal and external.

Aortoenteric fistula, or vascular fistulas, which are pretty darn rare in children, and generally a complication of inflammatory bowel disease or previous surgery, a rectal foreign body, a rectal ulcer, which is often associated with HIV, syphilis, or other sexually transmitted infections, or an anal fissure.

So all of these things are on the differential for lower GI bleeding. It’s important to note that if you see diarrhea with blood, as opposed to just frank blood, you should be thinking about infectious problems, like STEC causing organisms, like E. coli 0157:H7 which can lead to hemolytic uremic syndrome, or inflammatory bowel disease, or other problems.

So the diagnosis of Meckel diverticulum is called a meckle scan. I wonder how it got its name. It’s a technetium 99 pertectinate scan, and it’s the classic test of choice for diagnosis. It’s a nuclear medicine study, and the radioactive tracer is taken up by the gastric mucosa, which is in the Meckel diverticulum.

Therefore, it’ll show up on the radiology picture. The sensitivity is reported to be about 60 percent in adults, but 85 90 percent in children. The uptake of the dye can be increased by giving cimetidine or glucagon. So the feeding artery of the Meckel diverticulum is an anomalous branch of the superior mesenteric artery.

It has a long and non branching course and it ends generally towards the right lower quadrant. So the MEKL scan will help you pick up where that gastric mucosa is and then the surgeons can figure out how the blood supply gets there. Ultrasound and CT are not really good at differentiating a Meckel diverticulum from normal bowel.

So, if you think that somebody has a Meckel diverticulum, Here are some following management steps. If the patient has signs of obstruction, insert a nasogastric tube for GI decompression. Give broad spectrum antibiotics to cover potential bacterial infection, especially if the patient is ill appearing.

Give IV fluids packed red blood cells to resuscitate. A CBC and type and screen are great lamps to get. If there’s brisk bleeding or the patient’s unstable, consider COAGs. And yeah, you’re gonna want to consult a surgeon because that is how you deal with asymptomatic Meckel diverticulum. So if you’ve got complications such as significant bleeding, bowel obstruction or perforation, emergent surgical removal is warranted.

This can be done via a laparoscopic or open approach. So I’m going to wrap this up here. Again, this is a brief episode. A Meckle diverticulum is a congenital anomaly of the small intestine that can present with various clinical manifestations, including rectal bleeding. and bowel obstruction. Recognizing the characteristic features and understanding the differential diagnosis is crucial in managing patients with lower GI bleeding.

The Meckel scan is the preferred diagnostic modality. It’s a nuclear medicine scan and prompt surgical consultation is necessary for symptomatic cases. All right, so that’s it for this brief episode. If there’s other topics you want to see me tackle, send them my way. I’ll take your suggestions via email. Direct message on X or Twitter, Facebook, Instagram, telepathy. Any feedback is good feedback. Until next time, for PEMCurrents: The Pediatric Emergency Medicine Podcast, this has been Brad Sobolewski. See you later. 

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