Acute Aortic Dissection in Children

Happy 2023! Yes, I know that the Morsels have been “away” for a little bit. There is a high probability that I was just being lazy, but do not despair, the PedEM Morsels Bakery is back in business. Speaking of probability, a lot of our role in the ED is weighing and measuring probabilities for individuals based on their chief complaints, historic factors, and exam findings. Of course, our approach in the ED is a little different than the rest of the medical communities as we place more weight into the risk of morbidity and mortality while others approach the Ddx from a vantage of what is most probable. Yet, while we ponder the complexities of risk and probability, overlayed with our own risk tolerance, the individual patient either does or does not have the condition we are pondering. For the patient, it is binary. For us, it is a spectrum of risk and likelihood. This reality is faced when we ponder the Ddx of young patients with chest pain. Sure there are many conditions that warrant concern, but the likelihood is that the cause is benign. Unfortunately, the binary result may be devastating. Let’s take a moment to digest a morsel of information about one of these devastating, but rare, conditions – Acute Aortic Dissection in Children:

Acute Aortic Dissection in Children: Basics

  • Acute Aortic Dissection Pathology: [Fikar, 2000; Hua, 2015]
    • Occurs when an intimal tear develops allowing blood to dissect between the middle and outer two-thirds of the media of the aorta’s wall.
    • Usually occurs within 10 cm of the aortic valve.
    • The outer layer of the vessel, the adventia, is very thin.
    • The intramural hematoma may rupture into the:
      • Pericardium
      • Pleural space
      • Peritoneal cavity
    • Branch arteries from the aorta may also become completely or partially obstructed.
      • Signs and symptoms can be due to obstruction of these branch arteries.
      • May include coronary, carotid, renal, mesenteric, iliac, and/or spinal arteries.
  • Acute Aortic Dissection rarely occurs in children or adolescents. [Fikar, 2009]
    • International Registry of Aortic Dissection (IRAD) found only 0.76% of 1351 cases involved patient < 21 years.
    • Fikar’s study (12,142 cases) found 0.37% involved patients < 21 years.
    • There are other reports of up to 3.5% of aortic dissections occurring in patients < 21 years.
  • Mortality:
    • Overall mortality rates of pediatric cases noted to be ~13% [Fikar, 2009]
    • It is estimated, however, that for untreated dissecting aortic dissections that the mortality rate is 1-2% per hour over the 1st 48 hours of symptom onset. [Fikar, 2000]

Acute Aortic Dissection in Children: Associated Factors

  • Initiation and propagation of aortic dissections is believed to be related to: [Fikar, 2000; Hua, 2015]
    • Underlying Risk Factors:
      • Genetics and Predisposing conditions (ex, Marfan’s, Turner’s)
        • Up to 20% of patients with an aneurysm or dissection have a single-gene mutation that confers high risk. [Milewicz, 2019]
      • Inflammatory processes
      • Hypertension
      • Drugs (ex, Cocaine)
    • Intimal Tear
    • Dynamic forces that propagate the hematoma expansion
  • Trauma is a leading cause of cases (12-42%) [Fikar, 2009; Kothakota, 2014; Hua, 2015]
  • Non-Traumatic Associations [Fikar, 2000; Fikar, 2009]
    • Congenital Cardiovascular disorders
    • Connective Tissue Disorders
      • Marfan Syndrome
      • Turner Syndrome [Bondy, 2008]
      • Ehlers-Danlos Syndrome
      • Familial Cystic Medial Degeneration
      • Tuberous Sclerosis
    • Hypertension
    • Inflammatory Processes (ex, Giant-Cell Aortitis)
    • Pregnancy
    • Iatrogenic / Post-operative
    • Weight lifting/training
    • Idiopathic – cases with no identifiable risk factors. [Ngan, 2006; Matsushita, 2021]

Acute Aortic Dissection in Children: Presentation

Commonly reported symptoms are: [Kothakota, 2014; Hua, 2015]

  • Sharp pain in chest or back or abdominal pain
  • Pain often described as having an “abrupt” onset
  • Substantial drop in Blood Pressure
  • Pulse Deficit
  • Syncope

Acute Aortic Dissection in Children: Management

  • There are no current clinical guidelines on the management of pediatric acute aortic dissection. [Matsushita, 2021]
  • There is debate over optimal management of this rare condition in children. [Kothakota, 2014; Milewicz, 2019; Matsushita, 2021]
    • Need to factor in patient’s age and potential for continued growth.
    • Some advocate delaying repairs until the patient is 8-10 years of age, when a vascular graft of a sufficient size can be used.
    • If risk of rupture is high, may need to use smaller graft as a bridge and replace later.
  • Type A (involving the ascending aorta) generally is managed with surgical options.
    • Stent grafting has become the surgical intervention of choice for adults…
    • In children, currently available stents and potential for further growth limits their use.
  • Type B (involving the distal aorta) is often managed conservatively, unless complications are evident (ex, occlusion of branch artery).
    • Efforts to decrease factors that propagate the dissection
      • Decrease the blood pressure
      • Decrease the arterial impulse
    • Beta-Blockers (ex, esmolol, labetalol, or metoprolol) can reduce the pressure and the shear forces.
    • Vasodilators (ex, nitroprusside) can further aide in BP reduction.

Moral of the Morsel

  • It may be Rare, but if the child has it, they don’t care about probabilities. It is important for us to find a way to remain vigilant, but reasonable in our approach however.
  • Abrupt and Sharp Pain! Children are not aliens, and they actually present with Acute Aortic Dissection similarly to adults… we just need to listen to them.
  • This job is difficult. ‘Nuf said.

References:

Author

Sean M. Fox
Sean M. Fox
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