Trauma Surgery

The Chicken & The Egg

Which came first, the chicken or the egg?

Ancient Paradox

PPP vs Angiography, how comes first when facing an unstable patient with a pelvic fracture?

The two techniques should be complementary, as we may think!  But up to now, we are still lacking first quality proofs on which goes first. 

As we may know the majority of patients (around 80% of all the pelvic trauma) bleed from the venous plexus of the sacrum and pelvis. This is true, meaning that most of our patients will be treated with a pelvic binder. But here you have to pay a lot of attention: the more unstable the patient is, the more likely the bleeder is arterial! 

So, in a physiological stable patient with a pelvic fracture the pelvic binder is the first choice due to the venous bleeding, but in an unstable patient what should we do after the pelvic binder? Almost half of them (40% arterial and 60% venous in the study by Montmany et al.) are bleeding from an artery and the other half are bleeding from the venous plexus, depending also on the trauma mechanism!

Let’s start with reviewing how the two techniques work:

Angiography

It obviously works on arterial bleeding, we do not doubt that closing an artery won’t affect the venous bleeding (especially in the pelvis where the venous bleeding is from a wide net of small veins). To perform an angiography we need to have a proper radiology suite and an interventional radiologist. We cannot go deeper into this procedure because we lack a radiologist writing something for us, but what we need to know is that this procedure can and must be done with a pelvic binder on site. The pelvic binder can be moved a bit distally (and not cranially) to let the radiologist work, the radiologist may have to puncture the femoral artery a bit more cranially than usual but to open the pelvic binder with active bleeding will cause the patient bleeding even more!

PrePeritoneal Pelvic Packing

It works by decreasing/occupying the “empty” volume of a fractured pelvis. It needs to be combined with some sort of pelvic binder in order to “close” the pelvis from the outside and the inside. To perform it you just need a surgeon and a few instruments, nothing more. The PPP should also be done in the trauma bay without taking the patient to the OR! 

To do it, start with an infraumbilical midline incision or a Pfannenstiel incision, we prefer the midline: open the aponeurosis alone (not the peritoneum), you should find the hematoma coming out, it should have already done the dissection for you, if not you’ll have to dissect the Retzius space bilaterally to reach the sacrum and fill the space with laparotomy gauzes. Two different gauzes positioning school:

  • The first school says to use a Klemmer and open gauzes (better packing with no dead spaces, high risk to injure the patient due to the use of the Klemmer or yourself if you use your hands); 
  • The second school uses rolled up gauzes without pressing too much, put 3-4 per side (less potential lesion to the patient and yourself but more dead space among the gauzes).

Now that you have filled the Retzius space with gauzes you can close the skin (not the aponeurosis… You’ll have to take out those gauzes!)

The increasing pressure in the pelvis (coming from the inside due to the packing and from the outside due to the binding) should control the venous bleeding and the minor arterial bleedings! 

As you may remember from high school, the geometrical shape of the pelvis is a truncated cone, where the volume is:

Volume = (1/3) * π * Depth * (r² + r * R + R²) 

where R is a radius of the base of a cone and r of top surface radius.

Meaning any dislocation of pelvic bones will lead to a bigger radius, a bigger volume, and, consequently, to a bigger hematoma (i.e. blood loss)!!!

So it is natural that the first thing to do is to minimize the volume of the pelvis, starting with a pelvic binder (close the pelvis from the outside!).

Ok, this is the starting point… and now? 

If the patient stabilizes we can go on with the resuscitation, but what should we do if the patient is still unstable?

We do have to remember that every patient bleeding actively from the pelvis needs two treatments:

  1. Mechanical treatment (i.e. pelvic binder, PPP, angiography);
  2. Blood/plasma support transfusion and good resuscitation protocol!

There is a very interesting article from Gaski et al. from Oslow, reporting that the use of a good transfusion protocol reduces the need for PPP and angiography in pelvic trauma!

Gaski IA, et al.

Their conclusions are: “Extraperitoneal pelvic packing and angiography rates for exsanguinating pelvic injuries have decreased with improved resuscitation strategies, reducing RBC requirements and hemorrhage-related mortality. However, EPP still has a role as a lifesaving procedure in exsanguinating pelvic injuries not responding to resuscitation and in situations where angiography is not available.”

Now let’s get back to our physiologically abnormal patient even after the positioning of the pelvic binder. What should we do? Let’s follow the last DSTC book and the last WSES guidelines:

Coccolini F, et al.

In WSES IV pelvic lesions (unstable patients independently on the type of fracture), the first line of treatment after the pelvic binder is the PPP and then the angiography/REBOA/external fixation. 

As we know the bleeding site may also depend on the mechanism of the trauma. An open book fracture usually bleeds from the venous plexus as for the lateral compression mechanism, in these two situations the pelvic binder plus the PPP should stop the bleeding. Obviously, if the patient does not respond to these treatments, the next step will be angiography!
On the other side, a vertical sheer lesion will bleed more from an arterial source, meaning those patients should gain more from a pelvic stabilization with a pelvic binder (before closing it remember to realine as you can the two hemipelvis!) and then from angiography. 

It is also true that the PPP is still indicated when:

  • The angiography is not available;
  • Angiography won’t be available in less than 30 minutes (depending on the hospital but the concept is angiography is not immediately available!);
  • The patients cannot be moved to the angiography suite due to hemodynamic instability.

We hope it is stupid to say, but if the patient has intraabdominal bleeding (i.e. positive eFAST), the treatment is the laparotomy in the OR! There, the PPP can/should be done along with the trauma laparotomy!

We know that the guidelines and the actual bibliography are not helping us with a clear flowchart on what to do when facing a grade IV pelvic trauma (look at the red square of the previous flowchart). There are a lot of “+/-” depending on where you are and what is your/your team experience. We decided to create the following flowchart to help a bit clarify this deep fog we’re in. The following flowchart is then created based on the guidelines we have up to now, the courses we teach/have followed and our personal experience, so take it with care!

So, if we take again our first question, PPP and Angiography are complementary? The answer is YES! The difficult thing is to decide when to use one and/or the other. This decision is based on the resources you have (the hospital you’re in and its resources; is it day or night?), your experience, and the patient (every patient is different and you should be able to anticipate his/her physiology in order not to let him/her crash!)

As you have seen, we didn’t speak about pelvic external fixation. It has space if, after all your effort, the patient stabilizes. The patient can then be sent to the OR for temporary stabilization of the pelvis with external fixation done by our friends, the trauma orthopods! 

Remember that the pelvic binder can stay in place even for more than 24 hrs (the faster you can remove it the better), but this means that external fixation of the pelvis can be done also after some hours of physiological stabilization. You should not rush into the OR to fix a pelvis of an unstable patient right after his/her stabilization… He/she has time and needs time to stabilize the clots! 

As always, we hope this was of some help.

See you next time!
Namasté…

References
  1. Gaski IA, et al. Reduced need for extraperitoneal pelvic packing for severe pelvic fractures is associated with improved resuscitation strategies. J Trauma Acute Care Surg 2016;81:644-51.
  2. Montmany S, et al. Source of bleeding in trauma patients with pelvic fracture and haemodynamic instability. Cirugía Española 2015;93:450-4.
  3. Coccolini F, et al. Pelvic trauma: WSES classification and guidelines. World J Emerg Surg 2017;12:5.
  4. Boffard KD. Manual of Definitive Surgical Trauma Care. 5th Ed. Boca Raton, FL: CRC Press; 2019.
  5. Advanced Trauma Life Support: Student Course Manual. 10th Ed. Chicago, IL: American College of Surgeons; 2018.
How to Cite This Post

Marrano E, Navarro S, Bellio G. The Chicken & The Egg. Surgical Pizza. Published on November 29, 2021. Accessed on September 24, 2022. Available at [https://surgicalpizza.org/trauma/the-chicken-and-the-egg/].

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