Surgery: Intussusception

00:01 Welcome back.

00:02 Thanks for joining me on this discussion of intussusception in the section of pediatric surgery.

00:10 Intussusception, why does it happen? We don't exactly know, but there are some theories.

00:17 Most intussusception are idiopathic and they occur at the terminal ilium to the cecum.

00:23 This is also known as ileocolic.

00:26 This is the type that often happen in infants and toddlers.

00:30 Here, you see another anatomy picture of the terminal ilium actually invaginating itself into the colon.

00:39 There may be some truth behind probably lymph node hypertrophy.

00:44 Why? Because commonly this follows a recent respiratory infection.

00:50 We think with a systemic infection that the lymph nodes may actually hypertrophy and creating itself a lead point or idiopathic ileocolic intussusception.

01:03 Here is a picture of, intraoperatively, what we find in intussusception.

01:07 As you can see from this image, a segment of small intestines is invaginating into another.

01:13 This is the reason why it may cause obstruction and/or abdominal pain.

01:20 How does the intestines become ischemic during this process? I’ll show you using this image and the next few slides.

01:29 First, recognize that the lymphatic obstruction is actually what occurs first.

01:34 Commonly, when people think about intestinal ischemia, they think that the arterial supply is actually compromised first.

01:41 But there's a protective mechanism whereby the arterial blood pressure is usually the last to go.

01:47 After lymphatic obstruction, the venous side drainage is obstructed.

01:52 And now you can imagine, with lymphatics and venous obstruction, the inflow or arterial supply is subsequently obstructed.

02:01 This is like a multiple car accident.

02:04 There's going to be a pylon.

02:06 And towards the end of that scenario is arterial obstruction, and subsequently ischemia.

02:12 This is also a reason why, intraoperatively, you often see ischemic bowel very dilated.

02:17 That's because of the venous and lymphatic congestion.

02:22 Let's take a look at the schematic of what happens during an intussusception.

02:26 On the left side of the screen, as we already previously discussed, are potential etiologies of intussusception.

02:33 Remember, the vast majority of these are still idiopathic in kids.

02:37 Enlarged Peyer’s patches, particularly as associated with a viral upper respiratory infection, increases the chance of a lead point.

02:45 Additionally, some children may have an inflamed appendix, demonstrated in the left side of the screen.

02:51 As you can see on the right top half of the screen, the intestines proximally actually invaginates into the proximal small bowel.

02:59 And as a result, in the right lower quadrant of the screen, you notice that the intussusceptum, or the portion of the bowel that enters the proximal bowel, now appears edematous.

03:10 Upstream of this edematous bowel can present with small bowel obstruction.

03:15 As you can imagine, when venous and lymphatic drainage is obstructed, it may need to ultimately arterial obstruction and subsequent bowel ischemia.

03:25 Remember, lead points may not always be present.