Category Archives: Pelvis

Pelvic Fracture Intervention And Venous Thromboembolism Risk

Earlier this year, I wrote a series of posts on the two commonly used pelvic fracture interventions: preperitoneal packing (PPP) and angioembolization (AE). To sum up, both are equally effective in controlling hemorrhage, but the hospital costs for patients undergoing angioembolization are significantly less. This is probably because there is no need to perform repeated operations to insert and remove the preperitoneal packs when angiography is used.

But what about venous thromboembolism risk? Patients with pelvic fractures are already at high risk for it. Couldn’t the increase in pressure on the pelvic veins or the use of thrombogenic materials increase the risk? Authors from several well-known trauma centers collaborated to re-analyze data from the CLOTT study. This is another cute acronym for an extensive study, the Consortium of Leaders in the Study of Traumatic Thromboembolism. It looked at the incidence and risk factors for VTE in trauma patients. This analysis focused on VTE risk in patients with pelvic fractures, comparing those undergoing one of the two interventions with those who had neither.

Here are the factoids:

  • The original data were derived from a 17-center study conducted from 2018-2020; this study only included 1,387 patients who had pelvic fractures (as well as other injuries).
  • The primary outcome was the development of VTE during the hospitalization. DVT was detected using duplex ultrasound, and PE was detected by CT angiography. If pulmonary clots were seen without concomitant DVT, they were not considered to be of embolic origin.
  • For all comers, the overall incidence of VTE was 5.6%
  • Breaking them down by type, there were 2.7% PE, 2.7% DVT, and 1.9% pelvic thrombi (some patients had more than one event)
  • Chemical prophylaxis appeared to be very effective. If started within 24 hours, the incidence was 2.9% vs. 8.4%* if started later.
  • Missed doses did not appear to increase the incidence of VTE (about 5% for both groups)
  • Patients with PPP had a 9% incidence of VTE, pelvic angioembolization had 2.6%, and patients with ORIF had 16%. The incidence was 5.7% if no interventions at all were performed and 16% if more than one occurred.

Bottom line: There are a lot of tidbits in this paper. Most importantly, the use of PPP or AA does not significantly increase VTE risk. Interestingly, ORIF of the pelvis increases it. It’s not clear whether this is due to the procedure itself or is just a surrogate for the severity of pelvic injury. Multivariate analysis suggests that this is not a significant risk factor.

The finding that early chemoprophylaxis reduced VTE incidence to only 3% is very interesting. All too often, prophylaxis is delayed due to solid organ or head injuries. If it can be started safely in such patients, it should be to reduce the occurrence of this complication. One of the banes of management of major trauma is the potential need for repeated surgical procedures, which leads to a phenomenon known as “prophylaxis interruptus.” Thankfully, this study did not find that this increased VTE risk, although it did not stratify by how many doses were missed.

So put your mind at ease about increasing the risk of VTE risk by using procedures to decrease bleeding through mechanical means. But do remember to begin chemoprophylaxis soon and you safely can.

Reference: Does preperitoneal packing increase venous thromboembolism risk among trauma patients? A prospective multicenter analysis across 17 level I trauma centers. Journal of Trauma and Acute Care Surgery 97(5):p 791-798, November 2024.

Preperitoneal Packing vs Angioembolization For Pelvic Fracture

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.

 

The Peri-Mortem C-Section

The perimortem C-section (PMCS) is a heroic procedure designed to salvage a viable fetus from a moribund mother. Interestingly, in some mothers, delivery of the fetus results in return of spontaneous circulation.

The traditional teaching is that PMCS should be started within 4-5 minutes of the mother’s circulatory arrest. The longer it is delayed, the (much) lower the likelihood that the fetus will survive.

The reality is that it takes several minutes to prepare for this procedure because it is done so infrequently in most trauma centers. Recent literature suggests the following management for pregnant patients in blunt traumatic arrest (BTA):

  • Cover the usual BTA bases, including securing the airway, obtaining access and rapidly infusing crystalloid, decompressing both sides of the chest, and assessing for an unstable pelvis
  • Assess for fetal viability. The fundus must measure at least 23 cm.
  • Assess for a shockable vs non-shockable rhythm. If shockable, do two cycles of CPR before beginning the PMCS. If non-shockable, move straight to this procedure.

Bottom line: Any time you receive a pregnant patient in blunt arrest, have someone open the C-section pack while you assess and try to improve the mother’s viability. As soon as you complete the three tasks above, start the procedure! You don’t need to wait 4 minutes! And by the way, this is usually a procedure for surgeons only. They have the speed and skills to get to the right organs quickly. If unavailable, do what you need to do but recognize that the outcome may be even worse than it usually is.

Early Operative Fixation of Pelvic Fractures And Functional Outcome

Disruption of the pelvic bones takes a huge amount of energy, and results in significant bleeding and morbidity from other causes. Repair typically consists of surgical fixation, frequently with temporary external fixation in the interim. These patients require intensive therapy postoperatively, with inpatient rehab prior to discharge home.

How well do patients with severe pelvic fractures do in the longer term? The group at the University of Tennessee in Memphis did a lengthy followup study spanning 18 years of severe pelvic fractures treated at their hospital. These patients had sustained fractures with significant bleeding, an open book component, or SI joint disruption with vertical shear.

open book pelvis pre

The authors used phone interviews and a standardized measurement instrument (Activity Measure for Post-Acute Care, AM-PAC) to gauge daily activity of affected patients. They then looked for factors predictive of functional outcome.

Here are the factoids:

  • 401 patients were identified over the 18 year study period
  • Of these only 71% survived (285), and the study documented followup in 145 (51%)
  • Average ISS was 27 (fairly high) and patients tended to be older (mean 53 years)
  • Even after 8 to 20 years, mobility and activity were significantly impaired as measured by AM-PAC
  • Time to fixation was the only identifiable factor that had an impact on decreased mobility or activity

Bottom line: Early definitive fixation of the pelvis was the only variable found that had an impact on future mobility and activity. Frequently, external fixation is applied soon after admission. But remember, your trauma patient is at their healthiest as they roll through the doors of your ED. The sooner they get all of their problems fixed, the better (and safer).

Impact of early operative pelvic fixation on long-term functional outcome following sever pelvic fracture. AAST 2016, Paper 60.

Pelvic Binder Orthosis vs Pelvic External Fixation

In the “old” days, the recommended management for an unstable pelvis was application of an external fixator. In some textbooks, it was even suggested that this should be done (by orthopedics) in the resuscitation room. High volume trauma centers with ortho residents could actually pull this off, but not many others.

As the idea of pelvic orthotic binders caught on (T-POD, sheeting, etc) and was adopted by prehospital providers, and then trauma teams, the use of initial external fixation dropped off. But the idea that external fixation was the most desirable or most effective lingered on. A study from Memphis finally sheds some light on the answer to this question.

A 10 year retrospective review was carried out on patients presenting with multiple or severe pelvic ring fractures who had early stabilization of the pelvis. Stabilization consisted of external fixation early on, and gradually shifted to pelvic orthotic devices over the study period. They ultimately analyzed outcomes for 93 patients in each treatment group.

The authors found that transfusion needs were dramatically reduced with the orthotic devices (5 units vs 17 units at 24 hours) compared to the orthotics. About a quarter of patients in each group went to angiography, and even in those patients the transfusion need remained lower in the orthotic device group. Hospital length of stay was also significantly shorter in this group (17 vs 24 days). There was no difference in mortality.

Bottom line: Although this is a small, retrospective study it easily showed significant results and will probably never be repeated. Use of a pelvic orthotic device (POD) resulted in less blood replacement and shorter stays in hospital. This technique is simple, cheap and quick, an ideal combination. But does a sheet count as an orthotic device? We don’t know. It’s really cheap, but probably a bit less controlled than a POD. If you have a real POD in your ED or your ambulance, use it. If not, apply the sheet as described below.

Reference: Emergent pelvic fixation in patients with exsanguinating pelvic fractures. JACS 204:935-942, 2007.