Tag Archives: angioembolization

Abstracts, Solid organ

Best Of AAST 2022 #6: The “Missed” Splenic Pseudoaneurysm

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Like so many things in trauma, there are two camps when it comes to repeat CT scan after solid organ injury: the believers vs the non-believers. In my experience, a minority of US trauma centers incorporate this repeat CT study in their practice guidelines. 

Yet the question keeps coming up in the literature. Earlier this year, I reviewed a paper from the University of Cincinnati from a group of believers. I was not very kind, and you can read the review here. The biggest problem with most believer papers is that they cite very old literature that overstates the incidence of delayed hemorrhage. They then use this to justify an extra CT scan to find more of these “dangerous” pseudoaneurysms. Unfortunately, those old papers are just not very good and many overstate the problem.

So let’s look at this year’s abstract from the LAC+USC group. They open by stating that the natural history is unclear but that “risk for spontaneous rupture and exsanguination exist.” The authors sought to further define the utility of using a delayed CT angiogram (dCTA) in diagnosing and triggering intervention after high-grade blunt solid organ injury.

They performed a retrospective study of all patients arriving at their Level I center over a nearly five year period with a Grade 3 or higher injury to liver, spleen, or kidney. They excluded the young, patients transferred in, early deaths, and patients who underwent immediate operation on their spleen or kidney. The primary outcome was intervention triggered by the dCTA.

Here are the factoids:

  • A total of 349 patients with 395 high grade solid organ injuries were analyzed (42% liver, 30% spleen, 28% kidney)
  • Median injury grade for each organ was 3
  • Initial management was “typically” nonoperative or angioembolization (liver 83%, spleen 95%, kidney 89%)
  • Delayed CT angiogram was typically performed on day 4 and identified a lesion in 16 spleen, 10 liver, and 6 renal injuries
  • The dCTA prompted an intervention in 12 spleen, 8 liver, and 5 kidney injuries

The authors conclude that delayed CTA identified a significant number of vascular lesions requiring endovascular or surgical intervention. They recommend further examination and consideration of universal screening to avoid missing these pesky pseudoaneurysms.

Bottom line: Once again, we have a paper that conflates finding a pseudoaneurysm with the need to get rid of it. Granted, I was always taught that pseudoaneurysms (in adults) found on initial CT required an intervention. In the old days of “delayed splenic rupture” a pseudoaneurysm was the likely culprit. 

But the majority of centers do not go looking for pseudoaneurysms days later. And there are precious few patients coming back with delayed hemorrhage after discharge. So what gives?

Could it be that there is a difference between a “fresh” pseudoaneurysm and a “delayed” one? Perhaps the fresh ones portend a real risk of bleeding, but delayed ones are just a normal part of the healing process and rarely bleed? We just don’t know for sure.

This paper shows that if you look for a delayed pseudoaneurysm you will find them. And at this center, if you find them you will be compelled to angioembolize or even operate on them. Yet we really don’t know if that is necessary. It certainly adds to length of stay and hospital charges.

My take is that we desperately need a broad tally of patients discharged with a liver or spleen injury who return within a few weeks for bleeding complications. I would exclude kidneys because they act so differently. And I would not look at all returns because most liver injury readmissions are for bile problems. Just focus on readmissions for bleeding. Once we see what the real incidence is, we can decide whether these pseudoaneurysms are a problem significant enough to pursue with delayed scans, etc.

Here are my questions for the authors and presenter:

  1. What is your assessment of the incidence of delayed rupture and exsanguination? Have you read through the old papers in detail to assure yourselves that they are actually correct?
  2. Do you hold patients in the hospital for their delayed CT angiogram? The studies were typically performed on days 3-7. Do you really keep your solid organ injured patients in the hospital that long? At our center, a grade 3 injury could be discharged home in two days!
  3. How do you decide to take a patient to interventional radiology or the OR after the delayed CT? Is it an unwritten rule? It seemed like most, but not all, had some type of intervention. A (very) few had the lesion but nothing was done. Please explain the difference.

This is an interesting paper just because of the intuitive leap it makes from pseudoaneurysm to intervention. I’m anticipating your presentation so I can hear all the details.

Reference: PSEUDOANEURYSMS AFTER HIGH GRADE BLUNT SOLID ORGAN INJURY AND THE UTILITY OF DELAYED CT ANGIOGRAPHY. Plenary paper #34, AAST 2022.

Pelvis, Procedures

Preperitoneal Packing vs Angioembolization For Pelvic Fracture

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In my last post, I laid out the various options available for initial management of major pelvic fracture bleeding. Today, I’ll compare two of the newer tools: embolization (AE) and preperitoneal packing (PPP). In the next post, I’ll look at the data available for REBOA.

Interestingly, the use of AE and PPP vary geographically. Angioembolization has been a mainstay in the US for some time, and PPP has been more commonly used in Europe. The use of both is becoming more widespread, and each has its pros and cons.

Angioembolization requires the presence of a special interventional radiology team and a reasonably stable patient. The procedure can take some time, and the IR suite is not really the place to house an unstable patient. Preperitoneal packing requires a reasonably stable pelvis to hold the packs in place for optimal tamponade, which may require application of an external fixator at the time of the procedure.

But is one better than the other? A number of relatively small studies have been performed, which means that it is time to synthesize them and see if some clearer answers can be found. The trauma group in Newcastle, Australia did just this. They performed a systematic search of the literature, analyzing the impact of each procedure on in-hospital mortality.

Here are the factoids:

  • A total of 18 studies met the authors’ inclusion criteria: 6 studies on AE, 9 studies of PPP, and 3 that compared them to each other
  • ISS was significantly higher in the PPP group vs AE (41 vs 36)
  • Average time to OR in the PPP patients was 60 minutes vs 131 minutes to IR in the AE group (statistically significant)
  • A quarter (27%) of the PPP patients did not get adequate hemorrhage control and required AE
  • In-hospital mortality in the PPP papers was 23% vs 32% in the AE research
  • Mortality in the papers that compared AE directly to PPP wasno different

Bottom line: What does this all mean? Is packing “better” than embolization? The simple answer is that we don’t know yet. Due to the way this study was performed, it is not possible to tease out all of the possible confounders. 

We are taught that control of hemorrhage is paramount. The time to definitive management in the AE group was twice that of the PPP patients. This could have a major impact on mortality. Two hours of bleeding can certainly kill. And the lower mortality in the PPP group occurred even though their injury severity was higher.

Many trauma centers have both of these interventions available to choose from. How should we approach their use? Unfortunately the literature is still to scarce to come to strong conclusions. Until we have better research to learn from, I suggest the following:

  • Time is of the essence. Which procedure can you get the fastest? In many cases, this will be preperitoneal packing since it’s just a trip to your trauma OR, which should be ready and waiting. If you have an IR team standing by or available very quickly, you could consider them first.
  • Pay attention to hemodynamic stability. An IR suite is no place for an unstable patient. The resuscitation equipment is not on par with the OR, and one never knows exactly how long the procedure will last.
  • If you have a hybrid room, use it! This is the ideal situation. The surgeon can start the PPP while the orthopedic surgeon applies a fixator. And the radiologist can be preparing to finish it off with a quick squirt as soon as they move away from the groin.
  • The use of one does not rule out the other. If one fails and the patient has increasing fluid and blood requirements move immediately to the other procedure to try to get control.

Reference: Preperitoneal packing versus Angioembolization for the initial management of hemodynamically unstable pelvic fracture – A Systematic Review and Meta-Analysis. J Trauma, publish ahead of print, Jan 4 2022, doi: 10.1097/TA.0000000000003528.

 

Abdomen

Options For Hemorrhage Control From Pelvic Fracture

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We’ve come a long way in our available treatments to slow or stop bleeding from pelvic fractures. Let’s work our way through the list in today’s post, then look critically at two of the newcomers in the next one.

Pelvic binders. Long ago, these were just sheets wrapped around the patient and secured with clamps.

They were rather crude, as you can see. So of course, several enterprising companies began to offer commercial binders that were easier to place and secure.

Of note in the photo above, the wrap on the left is totally wrong. It is too wide and extends too high, so will not provide effective compression. The image on the right shows proper placement low across the greater trochanters. It is also not secured using metal clamps which may interfere with x-ray imaging.

External fixation of the pelvis. This usually involved a call to your friendly orthopedic surgeon. It could be applied in either the trauma bay or the operating room.

This image also shows improper technique. The horizontal bar should be angulated downwards over the pubis so it will not interfere with the trauma surgeon’s approach to laparotomy.

Internal pelvic packing + internal iliac artery ligation. Since surgeons didn’t have many other good tools, they could actually operate! Unfortunately, neither of these worked terribly well. The laparotomy pads could decompress upwards out of the pelvis and the internal iliac arteries have lots of collateral branches that permit ongoing bleeding from pelvic bones.

Angioembolization. Arterial bleeding from the pelvis occurs more often than you think (upwards of 50% of major pelvic injuries). Angiography and embolization can work very well. Unfortunately they are not suitable for unstable patients since IR suites are poor resuscitation areas. Many trauma centers do not have hybrid operating rooms where hemodynamically compromised patients can be taken for combined IR and open procedures if needed. So unstable patients must go to a regular OR first to attempt stabilization.

Preperitoneal packing. This is the new OR procedure kid on the block. Instead of placing packs in the pelvis, they are placed next to the broken pelvic bones but just outside the peritoneum. This permits better tamponade, and the intraperitoneal viscera push out against the packs to help decrease bleeding.

Zone 3 REBOA. And this is the very newest kid on the block. The balloon tipped catheter is inserted to a level above the aortic bifurcation but below the visceral and renal vessels. This is essentially a non-selective, temporary ligation of not just the internal iliac arteries, but everything distal to the aorta. It can be performed in the ED to dramatically slow blood loss, providing more time to get the patient to the OR where more definitive hemorrhage control can be provided (using many of the above techniques).

In my next post, I’ll take a closer look at the effectiveness of preperitoneal packing vs angioembolization.