All posts by The Trauma Pro

Abdomen, Abstracts, Solid organ

Best of AAST #10: Pediatric Contrast Extravasation And Pseudoaneurysms

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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.

Abstracts, Extremity

Best of AAST #9: Popliteal Atery Injury Repair

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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.

Abstracts, Complications

Best of AAST #8: Complications After Trauma Laparotomy

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With the introduction of damage control laparotomy (DCL) in the early 1990s, the trauma literature has focused on the nuances of this procedure. A significant amout of research has looked at patient selection, techniques, optimum time to closure, and complications afterwards. Studies on the single-look trauma laparotomy (STL) seem to have fallen behind. When compared to DCL, it seems to have relatively few complications.

But is that really so? A paper from the 1980s showed a nearly 50% complication rate after STL, but this included some trivial things like atelectasis which padded the numbers. A group at Scripps Mercy in San Diego looked at long-term complications after  STL in a state-wide California database. They were able to identify patients who underwent STL who were then readmitted for complications at a later date. They studied this data over an 8-year period.

Here are the factoids:

  • A total of 2,113 patients had a STL during the study period
  • One third (712) were readmitted at least once, with a median time to first readmission of 110 days
  • 30% of these patients had a surgery-related complication:
    • bowel obstruction 18%
    • infection 9%
    • incisional hernia 7%
  • Mechanism of injury was not related to development of complications

Bottom line: More than 10% of patients undergoing single-look trauma laparotomy develop significant complications. This is much higher than the complication rate seen after typical general surgical procedures. The difference between these groups and the reasons are not clear. Additional work must be done to tease out the risk factors, and our patients should be counseled on these potential complications and when to return for evaluation. Finally, the trauma surgeon should always use their best judgment to avoid an unnecessary trauma laparotomy.

Reference: Long-term outcomes after single-look trauma laparotomy: a large population-based study. Session IV Paper 14, AAST 2018.

Technology

Best of AAST #7: What’s New With Reboa

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Despite all you read about it these days, REBOA is still very new. The first papers describing use in humans are barely 5 years old! A few select centers have been early adopters and are publishing a regular flow of research on their experience.

But we need more numbers! Many trauma centers have considered, or actually adopted the use of REBOA already. However, we are still working out a lot of the nuts and bolts of this very invasive procedure. The group at University of Arizona – Tucson reviewed the national experience over a two year period by massaging the data in the Trauma Quality Improvement Program (TQIP) database. All Level I-III trauma centers in the US are required to report their experience to this large, detailed collection of trauma data.

They performed a retrospective review of REBOA vs non-REBOA patients matched for demographics, prehospital and emergency department vital signs, mechanism of injury, degree of pelvic disruption in pelvic fracture patients, solid organ injuries, and lower extremity fractures and vascular injuries. The studied outcomes were complications and mortality.

Here are the factoids:

  • Nearly 600,000 records were scanned for the two year period, and only 140 REBOA patients were identified (!)
  • These 140 REBOA patients were matched with 280 similar non-REBOA patients
  • Average age was 44 and average ISS was 29, 74% were males and 92% were blunt trauma
  • Overall complication rate was 7.4% and mortality was 25%
  • There was no difference in 4-hour or 24-hour numbers of blood, plasma, or platelets transfused
  • ICU and hospital length of stay were identical
  • 24-hour mortality in the REBOA group was significantly higher (36% vs 19%)
  • REBOA patients were significantly more likely to require amputation (5% vs 1%)

Bottom line: These are not great numbers for REBOA! What gives? There are a number of possibilities:

  • It’s a database study, so some key information might be missing
  • The numbers remain small, only 140 patients out of half a million records in two years!
  • There is no way to know how the patients were selected for REBOA
  • The experience and skill level at the hospital performing the procedure is not known
  • The interplay of other injuries and comorbidities is unclear
  • And many more…

BUT, the numbers are concerning. The early adopter centers have better outcomes, and this has prompted many centers with fewer eligible patients to jump on the bandwagon. We all need to remember that this is a brand new procedure and we are still learning the nuances. It is extremely important that every center performing REBOA contribute their results to a national registry. We still need to figure out which patients will benefit from it, how it should be used, and how we can minimize complications and maximize survival in our patients.

Reference: Nationwide analysis of resuscitative endovascular balloon occlusion of the aorta (REBOA) in civilian trauma. Session I Paper 5, AAST 2018.

Thorax

Best of AAST #6: Antibiotics For Chest Tubes??

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For as long as I can remember (nearly 50 years worth of literature) there has been some debate about giving antibiotics after chest tube insertion to decrease the infection rate. The pendulum moved back and forth for decades, never getting very far into the “give antibiotics” side. It’s been quite a while since I remember any new papers on this, and I thought the debate had been resolved in favor of never using them.

But then I see an abstract from the AAST multi-institutional trials group studying presumptive antibiotics after chest tube insertion! They conducted a prospective, observational study at 22 Level I trauma centers, enrolling nearly 2,000 patients. They matched patients in antibiotic and no antibiotic groups, arriving at (only) 272 patients in each group.

Here are the results:

Bottom line: First, it’s a little disappointing that the numbers were so low with a trial that includes 22 trauma centers. Did they have a hard time finding centers that would give antibiotics? Or was it just hard to match patients for the variables they were looking at? Regardless, there were no significant differences in infectious complications, and a non-clinically significant difference in ICU stay with antibiotics.

Why won’t this die? If there are so few papers that show an actual benefit from giving antibiotics after chest tube insertion with 50 years of data, then it’s very unlikely that it will ever be shown to be necessary!

Reference: Presumptive antibiotics for tube thoracostomy for traumatic pneumothorax. Session XXII Paper 49, AAST 2018.