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BackTable / VI / Article
Splenic Artery Embolization Procedure Considerations
Sai Govindu • Jun 16, 2023 • 220 hits
Splenic artery embolization is becoming a more popular treatment for hypersplenism and splenic artery aneurysms, and thus a nuanced understanding of varied methodologies, potential risks, and patient management strategies is needed to improve patient care for these individuals. Hypersplenism is caused by conditions such as cirrhosis and hematologic disorders. Treatment for hypersplenism involves embolizing specific spleen segments to improve platelet and white blood cell counts. According to interventional radiologist Dr. Chris Grilli, It's crucial to comprehend the morbidity and mortality rates linked to splenic artery embolization procedure and the importance of precise embolization estimation, highlighting the potential value of technologies like cone beam CT. A variety of devices, including coils, particles, and glue, can be used, providing significant flexibility to interventional radiologists. The management of splenic artery aneurysms, while less frequent, requires careful consideration of tools and strategies, with coils and occasionally covered stents serving as principal interventions. Post-procedure patient care, such as addressing vaccination concerns and managing pain after splenic artery embolization, is important.
This article features excerpts from the BackTable Vascular & Interventional Podcast. We've provided the highlights here, and you can listen to the full episode below.
The BackTable Brief
• Hypersplenism can be treated by embolizing and destroying specific portions of the spleen to increase platelet and white blood cell counts. Careful patient consultation is required due to the high morbidity and potential mortality associated with this procedure.
• Determining the proportion of the spleen being embolized can be done using imaging runs, cone beam CT, or more precise methods like measuring the feeding artery. The targeted proportion of the spleen for embolization lies typically between 40% to 70%.
• Different devices used for splenic artery embolization include coils, particles (3 to 500 or 5 to 700 microns), glue, and gel foam. The use of coils allows for precise control and enables a strategy called "tiger striping" where alternate branches are treated, minimizing the risk of a large necrotic area and potential complications such as abscess and sepsis.
• Coils, especially long packing coils, are the primary tools used in splenic artery aneurysm interventions. Other strategies can include using covered stents to maintain splenic flow, or distal and proximal coiling without packing the aneurysm sac.
• Patient care post-embolization often includes hospitalization and pain management strategies like PCAs, steroids, and Toradol. Patients do not need vaccinations after the procedure as long as some spleen is left behind.
Table of Contents
(1) Splenic Artery Embolization for Hypersplenism
(2) Splenic Artery Embolization for Aneurysm
Splenic Artery Embolization for Hypersplenism
Splenic artery embolization can be an effective treatment approach for hypersplenism in patients suffering from conditions such as cirrhosis, lymphoma, leukemia, and hematologic disorders. Hypersplenism treatment focuses on embolizing or effectively terminating flow to specific parts of the spleen, ideally ranging from 40% to 70% of the spleen, to elevate the platelet count and white blood cell count. However, it is critical to remember that this procedure can be associated with high morbidity and mortality rates. Estimating the extent of the spleen being embolized is typically done through imaging runs, although some practitioners may employ cone beam CT for a more precise measurement. An assortment of devices such as coils, particles, and glue can be employed for this procedure, offering considerable versatility to the interventional radiologist.
[Aaron Fritts MD]
Yes. That's good. Hypersplenism, I guess we could let our audience know why these patients are presenting and what the work-up is.
[Chris Grilli MD]
There are a number of reasons why we might embolize a spleen other than trauma hypersplenism being one of the major causes, either in a cirrhotic patient: someone with lymphoma and leukemia, somebody on chemotherapy or somebody with a hematologic disorder. We get a lot of these consults from our cancer center and our oncologists.
When I first started at Christiana, they weren't sending a lot of these, to be honest. Then I happened to have a discussion with an oncologist and with a low platelet patient who was not able to resume chemotherapy.
I told them about this and they seemed shocked and amazed that this was doable. They sent a patient who had a very robust response in their platelets and since then we've gotten quite a few more consults for these. This is a completely different reason than our trauma and a completely different way we do these cases. At the most basic level in the hypersplenism's platelet sequestration type case, we're looking to embolize and kill off part of the spleen rather than just slow flow into it. They did look at doing proximal embolizations and see if it had any effect on platelets. There were a couple of studies showing a little bump but I don't really believe them.
In general, the rule is a proximal embolization is not really going to have any effect on the size of the spleen or the platelet sequestration. Now we're talking about actually going into the segmental branches and taking out flow to certain portions of the spleen. The classic teaching is, well you take out about 40% to 70% of the spleen and that will give you a safe bump in your platelets, a reliable bump in your platelets, and even in your white blood cell count a little bit as well without having a ton of complications or not having very high complications.
This procedure is actually a pretty morbid procedure and I don't think people appreciate how dangerous this procedure can be. Certainly, when I get a consult for the oncologist, I want to see that patient in my IR clinic before I schedule them for the case because they need to know, the oncologist isn't telling them. They're telling the patient “they're going to do a noninvasive procedure, it's going to be fine, your platelets are going to bump up and then we're going to resume chemotherapy.” I need to talk to them seriously about the morbidity and mortality even with this procedure in the office.
I also explain to them that, "Hey, it's not going to be a smooth, smooth road. You'll probably be in the hospital a few days after the procedure. Pain after splenic artery embolization can be a lot, even though I'm going to give you a ton of pain medications. You're going to be nauseous. You're going to have this post-embolization syndrome and even after you get discharged, you're going to feel pretty beat up for a little bit.” It's not a procedure to be taken lightly as some of the referrers seem to think of it.
[Aaron Fritts MD]
You said about 40%, right? Is the target percentage roughly?
[Chris Grilli MD]
Yes, 40 to 70% depending on what you read.
[Aaron Fritts MD]
You're in the middle of your procedure. How do you determine percentage in? Do you use cone beam CT when you're looking for? Then you do like an injection and look for roughly calculating that percentage based off of enhancement? How do you determine that?
[Chris Grilli MD]
I would say the majority of the time I'm not using cone beam CT. However, it is definitely a good thing to use. I just tend to be inpatient and want to get out of the room as fast as possible. A lot of people do use cone beam CT to really get an accurate depiction of how much spleen you're actually taking out. I'm doing runs and trying sometimes different obliquities because you can get tripped out on a single view. I’m trying to estimate based on the runs, how much of the spleen roughly I'm taking on. I know it's not dead-on accurate and I have used cone beam in the past, but it gives me a general idea.
There's actually a really crazy study out of Japan where they actually looked into this and they measured the feeding artery and were able to accurately predict how much of the spleen they were devascularizing from taking out that feeding artery. That would be pretty cool to do, although you'd have to start measuring every artery and doing calculations along the side. Although it's neat, I don't see a ton of people doing that. The risk is you can go from and certainly I've been in this situation where I was at 40% and I'm like, "I want a little more, so I'll take one." Then boom, you're at 80% with the next embolization. It can go from too little to too much very quickly, so you got to be careful with that.
[Aaron Fritts MD]
Sounds like maybe a neat AI project if somebody could create an algorithm. I don't know if there’s really a product market fit there or like the need for it, but there's definitely a market fit. But I don't know if it is with the number of hypersplenism cases being done in the United States.
[Chris Grilli MD]
Probably be a little low.
[Aaron Fritts MD]
Stuff like that could be applied.
[Chris Grilli MD]
My gosh, totally. You could do a run. It can map out the arteries. You do a spin once in the beginning and then estimate based on what you've taken out. I could see that happening, measuring how much spleen you're taking out per branch. That'll be down the road. Just like in trauma, there's also a different number of devices we could use for this. We touched on this already. Going from gel foam, you could use coils, glue, and particles which are probably the most common.
I've used quite a few different things. I have used particles, 3 to 500 most often, and then sometimes 5 and 700 if we're talking a range micron for the branch, and goes very well. I think it's quick. I've also used a lot of coils. I really like using coils for this. It gives me very, very precise control. I can get into specific branches and I can even do tiger striping where I do a branch, I skip a branch, I do a branch etc. so that you don't have one large area of necrosis because certainly, the big fear is abscess and sepsis after this peritonitis and all the things that go with that.
The theory is you don't create one large necrotic area. Potentially you're going to get around that potential adverse event. Coils are also very, very good for this. They've done studies looking at this. Again, a lot of this is in the Japanese-Asian literature, but they've looked at coils versus gel and found that the complications were the same and the platelet increase was also the same. It really leaves a lot of options for the IR to decide what they want to use.
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Splenic Artery Embolization for Aneurysm
Splenic artery embolization can also be an appropriate treatment for splenic artery aneurysms, which are less frequent than hypersplenism but form an integral part of splenic interventions. Coils such as long packing coils are generally used in these cases. Alternative strategies, such as using covered stents in an effort to preserve flow to the spleen, or employing distal and proximal coiling without packing the aneurysm sac can be implemented based on the patient’s pathology. In most cases, it is recommended to leave a coil’s end sticking out due to the robustness of collateral flow to the spleen. Finally, as long as a spleen is left behind, vaccinations are not always necessary after splenic artery embolizations for aneurysm.
[Aaron Fritts MD]
How's trauma surgery deciding whether or not to send them to IR or take them to the OR? Is it based off of whether stable versus unstable?
[Chris Grilli MD]
In the most simplest form I always tell my residents, if it's a spleen that's unstable, those should be going to the OR. If it's a spleen that's stable, those are the ones that are considered for IR. Now, that's very oversimplified. In fact, there's a UMass study from, I think this year or maybe last year, that they were taking unstables and stables to the IR suite, and the complications and mortality were the same. There are exceptions to that rule. But in general, we're talking about an AAST one, even a two through five. If they're stable, you can do observation. If it's a higher grade, you take them to IR. If they're unstable, they pretty much automatically go to surgery.
Now, have I done unstable patients before in IR? Let's say there's a poor operative candidate or there's some other extenuating circumstance. You have to take each case by itself. Then if you consider, and so I said I'd mentioned this peds patient. For peds patients, it's a little different algorithm. Everything shifts to the left. No matter what their grade is, you're pretty much monitoring them as long as they're stable. It doesn't matter what the size of their hematoma is. Do they have a big peri splenic subcapsular hematoma? It doesn't really matter. You watch those. Only if they start to demonstrate that they're not improving clinically, would you even consider embolization. The criteria is even stricter for those type of patients.
[Aaron Fritts MD]
Are the peds patients more likely to go for embolization versus surgery if they're unstable?
[Chris Grilli MD]
They're more likely to do nothing. They're more likely to observe and it's very rare. If they're largely unstable, they're probably going to go to the OR. IR's role gets crunched a little bit in the middle. Again, this is all very institutionally dependent. A lot of studies have looked at this comparing institution versus institution and everybody has a little bit of a different algorithm, but definitely that's the trend that's seen out there. There's plenty of data in the trauma literature telling what we need to do. They have meta-analysis of 10,000 patients looking at grade four and fives and demonstrating a much-improved salvage rate with doing embolization versus just observation.
[Aaron Fritts MD]
In the peds population?
[Chris Grilli MD]
In the adult population. There are smaller studies in the ped population.
Podcast Contributors
Dr. Chris Grilli
Dr. Christopher Grilli is a practicing interventional radiologist with the ChristianCare Interventional Radiology Group in Delaware.
Dr. Aaron Fritts
Dr. Aaron Fritts is a Co-Founder of BackTable and a practicing interventional radiologist in Dallas, Texas.
Cite This Podcast
BackTable, LLC (Producer). (2022, December 9). Ep. 270 – Treatment Algorithms for Splenic Artery Embolizations [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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