Tag Archives: spleen

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.

Do Children With Low Grade Solid Organ Injury Need To Transfer To A Pediatric Trauma Center?

Pediatric trauma centers have an excellent reputation when it comes to caring for children when compared to their adult counterparts. Overall mortality for major trauma is lower. Splenectomy rates and the use of angiography are less in children with solid organ injury. And because of this expertise, it is common for surrounding trauma centers of all levels transfer these patients to the nearest pediatric trauma center.

But is this always necessary? Many of these children have relatively minor injury, and the pediatric trauma centers can be few and far between unless you are on one of the coasts. Researchers at the University of Washington, Harborview, and Seattle Children’s looked at their experience with pediatric transfers (or lack thereof) with spleen injury.

They retrospectively looked at 15 years of transfer data. The Seattle hospitals are the catchment area for a huge geographic area in the northwest, and the state trauma system maintains detailed records on all transfers to a higher level of care. Patients 16 years or younger with low grade (I-III) spleen injury were included. In an effort to narrow the focus to relatively isolated spleen injury, patients were excluded if they had moderate injuries in other AIS body regions.

Here are the factoids:

  • During the study, over 54,000 patients were admitted to hospitals, but only 1,177 had isolated, low grade spleen injury
  • About 20% presented directly to a Level I or II trauma center, 30% presented to a lower level center and were transferred, and 50% stayed put at the lower level center they to which they presented
  • 40 patients (3%) underwent an abdominal operation presumably for their spleen, but there was no difference based on which hospital they presented to or whether they were transferred
  • The incidence of total splenectomy was not different among the three groups
  • Likewise, there was no difference in ICU admission or ICU length of stay
  • The only significant difference was that patients who were not transferred to a pediatric center usually spent an extra day in the hospital

Bottom line: Injured children tend to do well, regardless of where they are treated. This study is huge and retrospective, which can cause analysis problems. And even given the size, the total number eligible for the study was relatively small. But it is the best study to date that shows that it is possible to treat select low grade injuries at non-pediatric, non-high level trauma centers. However, before going down this path, it is extremely important to define specific “safe” injuries to manage, and to have an escape valve available in case the patient takes an unexpected turn.

Post-Embolization Syndrome In Trauma

A reader requested that I write about post-embolization syndrome. Not being an oncologist or oncologic surgeon, I honestly had never heard about this before, let alone in trauma care. So I figured I would read up and share. And fortunately it was easy; there’s all of one paper about it in the trauma literature.

Post-embolization syndrome is a constellation of symptoms including pain, fever, nausea, and ileus that occurs after angio-embolization of the liver or spleen. There are reports that it is a common occurrence (60-80%) in patients being treated for cancer, and there are a few papers describing it in patients with splenic aneurysm. But only one for trauma.

Children’s Hospital of Boston / Harvard Medical School retrospectively reviewed 12 years of their pediatric  trauma registry data. For every child with a spleen injury who underwent angio-embolization, they matched four others with the same grade of injury who did not. A total of 448 children with blunt splenic injury were identified, and (thankfully) only 11 underwent angio-embolization. Nine had ongoing bleeding despite resuscitation, and two had developed splenic pseudoaneursyms.

Here are the factoids:

  • More of the children who underwent embolization had extravasation seen initially and required more blood products.  They also had longer ICU (3 vs 1 day) and hospital stays (8 vs 5 days). Not surprising, as that is why they had the procedure.
  • 90% of embolized kids had an ileus vs 2% of those not embolized, and they took longer to resume regular diet (5 vs 2 days)
  • Respiratory rate and blood pressure were higher on days 3 and 4 in the embolized group, as was the temperature on day 5 (? see below)
  • Pain was higher on day 5 in the embolized group (? see below again)

Bottom line: Sorry, but I’m not convinced. Yes, I have observed increased pain and temperature elevations in patients who have been embolized. Some have also had an ileus, but it’s difficult to say if that’s from the procedure or other injuries. And this very small series just doesn’t have enough power to convince me of any clinically significant differences in injured children.

Look at the results above. “Significant” differences were only identified on a few select days, but not on the same days across charts. And although the authors may have demonstrated statistical differences, are they clinically relevant? Is a respiratory rate of 22 different from 18? A temp of 37.8 vs 37.2? I don’t think so. And length of stay does not reveal anything because the time in the ICU or hospital is completely dependent on the whims of the surgeon.

I agree that post-embolization syndrome exists in cancer patients. But the findings in trauma patients are too nondescript. They just don’t stand out well enough on their own for me to consider them a real syndrome. As a trauma professional, be aware that your patient probably will experience more pain over the affected organ for a few days, and they will be slow to resume their diet. But other than supportive care and patience, nothing special need be done.

Related posts:

Reference: Transarterial embolization in children with blunt splenic injury
results in postembolization syndrome: A matched
case-control study. J Trauma 73(6):1558-1563, 2012.

Does Trauma Center Level Make A Difference In Treating Solid Organ Injury?

In the last two posts, I reviewed contrast anomalies in solid organs, specifically the spleen. Today, I’ll be more general and examine a recent paper that compared management and outcomes after the other major solid organ injury, liver, at Level I vs Level II trauma centers.

There are several papers that have detailed overall differences in outcomes, and specifically mortality, at Level I and II centers. Some of these show outcomes that are not quite as good at Level II centers when compared to Level I. On paper, it looks like these two levels should be very similar. Take away research and residents, and maybe a few of the more esoteric capabilities like reimplantation, and aren’t they about the same?

Well, not really. They can be, though. Level I criteria are fairly strict, and the variability between difference Level I centers is not very great. Level II criteria are a bit looser, and this allows more variability. Many Level II centers function very much like a Level I, but a few are only a bit higher functioning than a Level III with a few extra surgical specialists added in.

A paper currently in press used the Michigan Trauma Quality Improvement Program (MTQIP) data from all 29 ACS verified Level I and II centers in the state (wow!). Six years of information was collected, including the usual demographics, outcome data, and management. A total of 538 patients met inclusion criteria, and this was narrowed down to 454 so statistical comparisons of similar patients could be made for Level I vs Level II centers.

Here are the factoids:

  • Mortality was significantly higher in Level II centers compared to Level I (15% vs 9%) and patients were more likely to die in the first two days, suggesting hemorrhage as the cause
  • Patients were more likely to die in the ED at Level II centers, despite a significantly lower Injury Severity Score (ISS)
  • Pneumonia and ARDS were significantly more likely to develop in Level II center patients
  • Level II centers used angiography less often and took patients to the OR more frequently
  • Level II centers admitted fewer patients to the ICU, but ICU admission was associated with significantly decreased mortality
  • Complications were fewer at Level II centers, but they were less likely to rescue patients when they occurred

Bottom line: Level I and II centers are supposed to be roughly the same, at least on paper. But a number of studies have suggested that there are more disparities than we think. Although this paper is a retrospective review, the sheer number of significant differences and its focus on one particular injury makes it more compelling.

So what to do? Tighten up the ACS Orange Book criteria? That’s a slow and deliberate process that won’t help our patients now. The quickest and most effective solution is for all centers to adopt uniform practice guidelines so they all perform like the highly successful Level I programs in the study. There are plenty of them around. If you are not yet using one, I urge you to have a look at the example below. Tweak it to fit your center. And use your PI program to trend the outcomes!

Related post:

Reference: Variability in Management of Blunt Liver Trauma and Contribution of Level of ACS-COT Verification Status on Mortality. J Trauma, in press, Dec 1, 2017.

Natural History of the Splenic Blush

In my last post, I described the two types of solid organ “blushes.” I also described my thoughts on the natural history of these findings. Now, a multicenter study on the natural progression of the splenic “blush” has just been published. I found this paper very interesting, because it challenged some of my own existing beliefs. But once I read it, my enthusiasm faded.

The Western Trauma Association sponsored a multicenter (17 Level I and II centers) review of data collected prospectively over an unspecified period of time. Patients were excluded if their injury was older than 24 hours, if they had a previous splenic injury, and if they had any number of diseases or hereditary conditions that might affect the spleen. Strict definitions of nonbleeding and actively bleeding injuries were applied, and detailed information on intervention and outcomes was collected.

Here are the factoids:

  • 200 patients were enrolled from 17 centers, but the paper does not state how long that took
  • 20% were low grade (1 or 2) and 80 % high grade (3-5)
  • 29% had a pseudoaneurysm, and 83% showed extravasation, which means that several patients had both
  • 15% underwent early splenectomy, 59% underwent angiography, and 26% were observed
  • For those with initial angiography, 6% had repeat angio and 7% eventually underwent splenectomy
  • Of those were were initially observed, 9% had delayed angio and 8% underwent splenectomy
  • Based on a read by an expert radiologist, an actively bleeding injury was associated with a 41% splenectomy rate
  • The authors conclude that the majority of patients with spleen injury with pseudoaneurysm or extravasation are managed with angio and embolization and that splenectomy remains a rare event (??)

Bottom line: This paper just doesn’t do it for me. The biggest problem is that it is what I call a “we do it the way we do it” study. It examines how 17 different centers evaluate and treat patients with significant splenic injury. There was no guidance or guideline on how to treat, so they each did it their way. And the number of patients was small.

They don’t tell us anything about the use or effectiveness of angio by grade. Or whether the specific hospitals routinely rely on angio rather than just going to the OR for high grade injuries (typically if angio response times are long).

Unfortunately, this paper gives the appearance of containing a lot of interesting stuff. But a 15% initial splenectomy rate is not a “rare event” in my book. Everything published here is at odds with what I’ve observed over the years for centers with well developed management guidelines and easy access to angio (< 5% splenectomy rate in hemodynamically stable patients with nonoperative management).

My recommendation is to send all stable patients with pseudoaneursym and/or extravasation to angio immediately! Yes, some will have nothing found by the time they get to angio, and you’ll have to come up with a plan at that point. But most have something wrong, and it won’t stop until it’s been plugged up (or your patient bleeds to death, whichever comes first)!

This article has all the right buzzwords: multicenter, prospective data, etc. But it’s already been moved to my recycle bin. 

Related post:

Reference: Natural history of splenic vascular abnormalities after blunt injury: A Western Trauma Association multicenter trial. J Trauma 83(6):999-1005, 2017.