Tag Archives: abstract

Best of AAST #10: Pediatric Contrast Extravasation And Pseudoaneurysms

There is a significant amount of variation in the management of pediatric solid organ injury. This is well documented between adult and pediatric trauma centers in t, but also apparently between centers in different countries. A poster from a Japanese group in Okinawa Japan will be presented this week detailing the relationship between contrast extravasation after spleen or liver injury and pseudoaneurysm formation.

In adults, the general rule is that pseudoaneurysms just about anywhere slowly enlarge and eventually rupture. This group sought to define this relationship in the pediatric age group. They performed a multi-center observational study of retrospectively enrolled children, defined as age 16 and less. Those who had contrast extravasation on initial CT were monitored for later pseudoaneurysm formation.

Here are the factoids:

  • 236 patients were enrolled across 10 participating centers, with about two-thirds having liver injury and the remainder with splenic injury
  • 80% of patients underwent followup CT scan (!!)
  • 33 patients (15%) underwent angiography (!!!!)
  • 17 patients with CT scan (2%) had pseudoaneurysm formation and 4 of them had a delayed rupture
  • Overall, pseudoaneurysms occurred in 29% of those with contrast extravasation and 5% without extravasation
  • The authors concluded that contrast extravasation was significantly associated with pseudoaneurysm formation after adjusting for variables such as ISS, injury grade, and degree of hemoperitoneum

Bottom line: This is an abstract, so a lot is missing. What was the age distribution, especially among those who underwent angiography? Was the data skewed by a predominantly teenage population, whose organs behave more like adults? The abstract answers a question but ignores the clinical significance.

For those trauma professionals who routinely care for pediatric patients, you know that contrast extravasation in children doesn’t act like its adult counterpart. Kids seldom decompensate, and for those who are mistakenly taken for angiography, the extravasation is frequently gone. The authors even admitted in the conclusion that aggressive screening and treatment for pseudoaneurysm was carried out.

The real question is, what is the significance of a solid organ pseudoaneurysm in children? Based on my clinical experience and reading of the US literature, not much. Of course, there is a gray zone as children move into adulthood in the early to mid-teens. But this does not warrant re-scanning and there should be no routine angiography in this age group. Contrast extravasation in pediatric patients warrants close observation for a period of time. But intervention should only be considered in those who behave clinically like they have ongoing bleeding. 

Reference: Association between contrast extravasation on CT scan and pseudoaneurysm in pediatric blunt splenic and hepatic injury: a multi-institutional observational study. Poster 31, AAST 2018.

Best of AAST #9: Popliteal Atery Injury Repair

Injury of the popliteal artery is potentially devastating. Since this vessel is essentially and end artery, any complication resulting in thrombosis can result in limb loss. Traditionally, significant injuries have been treated with open repair and/or bypass. However, endovascular therapies have been making inroads in this area. Short-term outcomes appear to be equivalent. But what happens in the long term? Is one better than the other?

Scripps Mercy in San Diego (yes, same as yesterday’s abstract!) performed a retrospective review of the same California state discharge database. This time, they focused on patients with popliteal artery injury, and the attendant complications of fasciotomy and amputation. They stratified the patients into open and endovascular groups.

Here are the factoids:

  • 769 patients with popliteal artery injury were identified over an 8-year period
  • 59% were managed with an open operation, 4% using endovascular techniques, 2% combined, and 34% nonoperatively
  • Fasciotomies were performed significantly more often in the open group (41% vs 19%)
  • More amputations were performed in open cases, but this was not significantly different (11% vs 3% [1 patient in the endovascular group])
  • Embolism or thrombosis was significantly more likely during the first admission in endovascular or combined endo/open cases
  • Patients requiring both endo and endo+open procedures  were 5x more likely to undergo a later amputation, and 4x more likely to die after discharge

Bottom line: First, remember the limitations of this study: (very) small numbers, and a large database that precludes teasing out details. It suggests that open repair of popliteal injury is superior to endovascular due to higher thrombosis/embolism and amputation rates. Performing a fasciotomy is somewhat subjective, and may be done by surgeon preference to protect the limb. But amputation is more objective.

Unfortunately, we will not get anything more definitive any time soon. This 8-year analysis of a huge state database yielded only 769 cases, or 96 per year. In a state with 39 million people. That’s three injuries (reported) per million people per year. We will never generate a study that will tell us the full answers. But in the meantime, consider endovascular repair of popliteal artery injury only in patients for whom an open procedure is more challenging or risky (e.g. obesity, associated wounds).

Reference: Outcomes for popliteal artery injury repair after discharge: a large-scale population-based analysis. Session XXII Paper 55, AAST 2018.