Emergency General Surgery

In#!@$*ception

There is a light at the end of the tunnel… hopefully it’s not a freight train!

Mariah Carey

Welcome back, guys!!!

As you already know, in one of our previous posts we have analyzed the main cause of large bowel obstruction and the different management strategies depending on the colorectal segment involved. However, patients presenting with intestinal obstruction have more often the small bowel involved.

Grossly, the small bowel obstruction (SBO) can be divided into two big families: the adhesive SBO (ASBO) and the non-adhesive SBO (NASBO). The majority of SBO is secondary to an adhesive process, where only a few cases refer to non-adhesive etiologies.

We are going to explore the complex world of ASBO in dedicated posts (they are on their way, don’t worry!!!). In its place, today’s special is one of the rarest NASBO: the intussusception.

We are sure you are asking yourself: “Why the hell are they talking about something so rare instead of a more frequent and important topic?”… Well, the answer is quite simple: because we want to get you prepared for the craziest things that may happen to you!

(And remember that if you want us to write a post on a particular subject you can simply ask us… We are here for you all!).

Introduction

Intussusception is a telescopic penetration of a segment of the gastrointestinal (GI) tract, called “intussusceptum”, into the lumen of its distal segment, called “intussuscipiens”. This condition usually involves children; however, in some cases, it may affect adults. In general, adult intussusception accounts for about 5% of all intussusceptions.

There is a major difference between child and adult intussusception, and it is represented by the main causative agent: in children, it is usually the consequence of the more pronounced peristaltic movements and the greater laxity of the mesentery, whereas in adults about 90% are secondary to well defined pathologic conditions, 65-70% of which are represented by malignancies.

In this post, we will focus on just adult intussusceptions.

The most common GI tracts involved by intussusception are the small bowel and the cecum. However, intussusception may rarely affect other gastrointestinal segments (e.g. stomach).

In adults, the process leading to intussusception usually involves a leading point, which may be intraluminal (e.g. malignancy, polyp…) or extraluminal (e.g. diverticulum, adhesive band), that causes a dysperistaltism that “suck” the proximal GI tract into the distal one.

Diagnosis

Intussusception clinical presentation in adults is aspecific, and the classical triad of cramping abdominal pain, palpable abdominal mass, and blood mucoid stool often seen in children is extremely rare. Usually, patients present complaining about recurrent cramping abdominal pain and/or symptoms of intestinal obstruction. The clinical examination findings may be as variable as the symptoms.

Unfortunately, the first imaging exam asked for is a plain abdominal x-ray (AXR), which is useless. Remember that plain AXR has no indications at all. It does not help in making a diagnosis… Ever!

Other imaging techniques used in these patients are upper GI contrast series and barium enema examination. However, the two most useful radiologic exams are abdominal and GI ultrasound, and obviously contrast-enhanced abdominal CT scan, which may reach 100% accuracy and sensitivity.

Small bowel intussusception in a patient with Peutz-Jeghers Syndrome

The importance of CT scan is that it allows obtaining information about the localization of the segment involved, its length, the possible vascular impairment, the primary cause (e.g. malignancy, diverticulum, etc…), complications (e.g. bowel necrosis, bowel perforation, etc…).

An intussusception with a lead point appears on CT scan with signs of bowel obstruction, bowel wall edema with loss of the classic three-layer appearance secondary to impaired mesenteric circulation, and with the lead mass within. On the other hand, an intussusception without a lead point does not show signs of proximal bowel obstruction and it presents with a target-like or sausage-shaped mass or layering effect.

However, no matter how good the CT scan is in detecting an intussusception, most often the diagnosis is carried out during the surgical procedure.

Treatment

If in children with intussusception surgery is usually unnecessary and possibly avoided because of the low risk of obstruction and underlying neoplastic disease, in adults the story is quite different. As we have already said above, in adults 70% of intussusceptions are the consequence of malignancies; therefore, surgery becomes mandatory in this situation.

However, there are at least three major issues with surgery in adult intussusceptions: Open or laparoscopic? Oncologic or segmental resection? To reduce or not to reduce the intussusception?

As always, the surgical approach should rely on the surgeons’ experience and skills. No specific contraindications to laparoscopic surgery exist in the case of intussusception. Moreover, an exploratory laparoscopy may be useful to make the diagnosis in case of a non-diagnostic CT scan.

Whether to proceed with oncologic resection is still debated. However, provided the high incidence of malignancies in adult intussusceptions, it may seem reasonable to remove part of the mesentery with its lymph nodes (at least if a mass is found within the bowel loop).

To reduce or not to reduce, this is the question… Well, since you have to remove the bowel segment involved in the intussusception, reducing the loop does not seem the right choice. In fact, if the loops are fragile, reducing the bowel may lead to perforation with contamination of the surgical field. Moreover, some authors believe that reducing an intussusception with a neoplastic mass within may cause cancer seeding and delayed recurrence.

Intussusception is a rare condition causing bowel obstruction and/or abdominal pain in adults; however, its diagnosis may be tricky…

We do not advocate the idea of thinking about zebras when you hear hoof noise, but at least you need to remember that zebras have hooves…

We hope you’ve appreciated this post… If you did, please share it with your friends…

See you soon… and remember to be good, be brave, be an acute care surgeon!

References

  1. Bellio G, et al. Small bowel intussusception from renal cell carcinoma metastasis: a case report and review of the literature. J Med Case Rep 2016;10:222.
  2. Marinis A, et al. Adult bowel intussusception: presentation, location, etiology, diagnosis and treatment. G Chir 2013;34:280-3.
  3. Begos DG, et al. The diagnosis and management of adult intussusception. Am J Surg 1997;173:88-94.

How to Cite This Post

Bellio G, Marrano E. In#!@$*ception. Surgical Pizza. Published on January 23, 2022. Accessed on July 24, 2022. Available at [https://surgicalpizza.org/emergency-surgery/ inception/].

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