Best Of AAST #11: Hard Signs Of Vascular injury

The next abstract in this series poses a challenge to long-held dogma. More than three decades ago, examination of vascular injuries was divided into “hard signs” vs “soft signs.” Hard signs consisted of findings like pulsatile hemorrhage, expanding hematoma, absent distal pulses, thrill, or bruit. These were believed to be absolute indications to proceed directly to the operating room for exploration and repair.

But now, in this day and age of CT angiography  (CTA)and all manner of endovascular techniques and tools, things seem to be changing. There is more reliance on CTA, and a willingness to image patients with hard signs before considering an operation. But is this prudent?

The AAST established the Prospective Observational Vascular Injury Treatment (PROOVIT) database as a multi-institutional effort involving major trauma centers around the country in 2013. A group based at the Massachusetts General Hospital massaged the data to study current patterns in assessment and management of patients with penetrating extremity vascular injury. Specifically, they were interested in examining the presence of hard signs and the outcomes after initial imaging and operative management.

Here are the factoids:

  • A total of 1,910 database records were reviewed, of which 1108 (58%) presented with hard signs of injury
  • 83% of the patients with hard signs had either active hemorrhage or expanding hematoma; only 15% had ischemia
  • CTA was used in a quarter of patients with hard signs (24% hemorrhagic, 40% ischemic)
  •  Two thirds of patients with hard signs were taken to OR without imaging (70% hemorrhagic, 45% ischemic)
  • Open repair was performed in about two thirds of hemorrhagic and ischemic patients both with and without imaging, but endovascular  or hybrid repairs were 5x more likely (2% vs 10%) in patients who underwent imaging first
  • There were no differences in outcomes (amputation, mortality, blood transfusions, reoperation) between the open and endovascular/hybrid repair groups

The authors concluded that stable patients with hard signs of vascular injury may benefit from preop imaging to help plan the specific mode of repair to be performed (open vs endovascular / hybrid).

Here are my comments: This was a retrospective review of prospectively collected data. The database has a wealth of detail, and this is a simple and clean analysis of a specific question. The results and analyses were straightforward and easy to follow.

What this study does is to call into question the old dogma of rushing straight to the operating room with any patient who has hard signs of vascular injury. The advent of endovascular tools and techniques has allowed us to more easily address some vascular injuries that were previously problematic due to their location and accessibility.

Being a descriptive study only, it showed us “what we did” with vascular injuries during the time period of the database. And it also showed that the surgeons were more likely to use endovascular techniques if they were able to take the time for preop imaging. Most importantly, it demonstrated that gross outcomes like death, reoperation, and amputation were not increased by the delay needed to obtain that imaging.

I consider this to be a pilot project. And the authors correctly state that the next step is a true prospective study to confirm that this should be the new way of thinking about hard signs in the future.

Here are some questions for the presenter and authors.

  • Please provide more information on the database records used. Which years were included? What were the inclusion criteria? Were any patients excluded?
  • What was the definition of a vascular injury to the extremity? Did it include the very proximal brachial artery or the distal subclavian? These may increase the likelihood of choosing an endovascular repair.
  • Did you stratify by type of penetrating injury (stab vs gunshot) or velocity (assault rifles and shotguns)? These will increase the likelihood of proceeding directly to OR and potentially skew the data.
  • Some data from the abstract is missing, typically p values. This appears to be a glitch with the abstract entry system, since it is a problem in other abstracts as well.
  • How long do you think it will take to collect adequate data from a prospective study so that preop imaging in stable patients becomes the new standard of care?

This was a fun abstract to read! I’m looking forward to the presentation next week.

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