Sandbox SSW

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sargun Singh Walia M.B.B.S.[2]

Overview

The exact pathogenesis of intussusception is not fully understood. It is thought that intussusception is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].

OR

[Pathogen name] is usually transmitted via the [transmission route] route to the human host.

OR

Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.

OR

[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].

OR

The progression to [disease name] usually involves the [molecular pathway].

OR

The pathophysiology of [disease/malignancy] depends on the histological subtype.

Pathophysiology

Pathogenesis

The exact pathogenesis of intussusception is not fully understood. Under normal conditions, a balance between the longitudinal and radial forces maintains the normal structure of intestine. Intussusception occurs if there is an imbalance between the longitudinal forces. This imbalance leads to a segment of intestine to invaginate into another segment and cause entero-enteral intussusception. The proximal portion is called intussusceptum and the distil portion is called intussuscipien. If this telescoping of the intestine continues it can extend till distil colon or sigmoid colon or even through the anus.

Intussusception(Source: By Olek Remesz (wiki-pl: Orem, commons: Orem) (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)

Types

Ileocolic

Ileo-Ileo-Colic

Jejuno-jejunal

Jejuno-Ileal

Colo-Colic

• Intussusception is the most common abdominal emergency in children < 2 years of age.

Children

Idiopathic- no lead point

Pathologic- Lead point

• uncommon in adults but when it occurs the most common cause is pathological due to lead point.

If the mesentry invaginates along with the intestine it can lymphatic and venous congestion leading to intestinal edema. If not treated then eventually it leads to ischemia which further can lead to peritonitis or even perforation.

Etiology

• Idiopathic:- It is the most common cause of intussusception in children and accounts for about 75% of all cases.Any specific disease trigger point or lead point cannot be recognized. It can be further divided among various causes:
  • Viral Cause
    • Seasonal viral gastro-enteritis.
    • Rotavirus Vaccine:- Intussusception is known to be caused by certain types of Rotavirus Vaccines. An earlier iteration of the vaccine known as the Rotashield was taken out of the market because it was associated with an increased number of cases of intussusception. If there occurs any case of intussusception after vaccination with rotavirus vaccine, then it should be reported to the Vaccine Adverse Event Reporting System (VAERS) by the providers.
    • Adenovirus:- There is a strong association with adenovirus infection. A case control study conducted in Vietnam and Australia shows that Specie C of adenovirus is a strong predictor of intussusception in children.
    • Viral infections stimulate the lymphatic tissue in the intestine and lead to the hypertrophy of the payers patches in the terminal ileum and cause the formation of a lead point. This may act as an obstruction and lead to intussusception. Due to this association with hyperplasia, use of glucocorticoids may be used to prevent recurrence but it is not encouraged.
  • Bacterial enteritis:- A retrospective cohort study done in children aged 0-5 years shows a strong association between bacterial enteritis and intussusception. There is an increased risk of development of intussusception with Shigella, Salmonella, E coli and Campylobacter infections.
• Lead Point:- Lead point can be defined as any lesion that gets trapped in the intestine by peristaltic forces, which then gets dragged into the distal segment of the intestine leading to the formation of intussusception. Lead point accounts for 25% cases of iintussusception in childhood and almost 95% of cases of intussusception seen in adults. Lead point can be caused due to various pathological reasons which are as follows:-
  • Henoch-Schönlein purpura (HSP):- It is is an IgA mediated inflammatory disorder which causes inflammation and bleeding of the small blood vessels in skin, intestine, joints, and kidneys. HSP is most commonly seen in children less than 7 years of age. In HSP, hematoma formation in the small intestine may act as a lead point. Intussusception mostly occur once the abdominal pain subsides.. Intussusception in HSP mostly originates in the ileum or jejunum , and more than one-half of cases are confined to the small bowel. In contrast to idiopathic intussusception, where the majority (80%-90%) are ileo-colic.
  • Cystic Fibrosis:- Intussusception is one of the complication of cystic fibrosis. In this thick inspissated/impacted stool acts as a lead point.
  • Celiac disease:- Recent studies show that celiac disease is associated with increased risk of intussusception. Celiac disease may lead to small bowel intussusception by causing dysmotility and excessive secretions in bowel wall or by causing small bowel weakness.
  • Crohns disease:- Crohns disease is a chronic granulomatous inflammatory disease which may lead to intussusception due to inflammation and stricture formation in the intestine.

Genetics

• [Disease name] is transmitted in [mode of genetic transmission] pattern.
• Genes involved in the pathogenesis of [disease name] include [gene1], [gene2], and [gene3].
• The development of [disease name] is the result of multiple genetic mutations.

Gross Pathology

• On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].

Microscopic Pathology

• On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].