Robert Morgan, St George’s University Hospitals NHS Foundation Trust, London, UK, discusses the role of interventional radiologists (IRs) in trauma embolization; and whether other clinical specialties with aspirations to perform these techniques should be involved in offering this treatment. Working at a major trauma centre, Morgan, who sees between 100 and 200 traumatic haemorrhage cases a year, highlights the difficulty of the embolization techniques, and explains how important it is that only specialists with proper training should perform these procedures.
At the recent Global Embolization Cancer Symposium and Technologies (GEST) US meeting (9–12 May, Miami, USA), there was a discussion on the topic of embolization and turf. What recent developments suggest that trauma embolization is the next battleground for IRs?
GEST (US) is a North American meeting, and it may be the case that there are more concerns about turf issues in embolization in North America than there are in Europe. However, that is not to say that European IRs should be complacent about this. I think that there are potential issues regarding inadequately trained non-IRs performing embolization procedures, certainly in the trauma field. I am aware that this already occurs in some centres in Europe. In some European hospitals, non-IR trauma specialists advocate that they should be able to perform the full range of treatments for trauma, and that this should include embolization for haemorrhage. These individuals have stated that this approach would be better for patients, without any real evidence base for it.
From my point of view, I disagree with the view that embolization for traumatic haemorrhage is a technique that can be learnt relatively easily by other specialties with no formal training in catheter/guidewire/embolization techniques. I know that our vascular surgical colleagues perform some embolization procedures in connection with EVAR such as plug embolization of the internal iliac arteries and in a few European centres, embolization of endoleaks. However, I do not think that there is a growing enthusiasm from vascular surgeons to take this to the next level and perform embolization of haemorrhage using microcatheters. In the main, I do not see the likelihood of non-IRs performing embolization of haemorrhage as an imminent problem in the UK, and also probably in Europe. However, this is not to say that IRs should be complacent about their role in embolization for haemorrhage.
In my opinion, it is difficult to say that certain specialists cannot perform specific procedures that other specialists do, such as embolization. We have already experienced turf issues between IRs and other specialties in terms of the endovascular treatment of lower limb peripheral vascular disease. From this experience, I do not consider that it is productive to state that one specialty cannot do a procedure that another specialty does. We have to rely on best practice, and ask the question whether the person who wants to take on that procedure is trained to do it sufficiently well enough, according to published professional Standards of Practice guidelines for that specific procedure. It is evident from prior experience with other clinicians who want to perform procedures performed by IRs (for example, uterine artery embolization, or dialysis interventions) that this may not always be the case.
How important is embolization in treating trauma patients?
Embolization is very important for haemorrhage management in trauma. Certainly, not all cases of traumatic haemorrhage require management by embolization. However, there is a subset of patients with haemorrhage from certain abdominal organs, where the standard of care is focused on embolization rather than surgery. Therefore, embolization is integral to the management of some patients with traumatic haemorrhage.
In an interventional radiology list of seven to 12 cases, maybe one or two of those cases will be embolization procedures. In terms of embolization for trauma, maybe one case in 30 to 50 cases. A typical scenario is the patient who has been involved in a road traffic accident and has sustained splenic trauma, usually in the middle of the night.
What constitutes adequate training to perform trauma embolization?
Trauma embolization is just one of the spectrum of cases that are treated by embolization. The procedures are often challenging, requiring endovascular access to small vessels in tortuous arterial territories. Therefore, you need to acquire the skills to be able to access the site of haemorrhage using standard catheters and microcatheters, and standard wires and microwires. You also need to have knowledge of the different types of embolic agents, in which situations to use them and the skills to be able to use them safely. These are not easy skills to acquire. The catheter and guidewire skills necessary to manipulate catheters and guidewires around the relevant arterial territories take time to acquire, and are a considerable step up from the ability to manipulate catheters into relatively large visceral arteries such as renal arteries. Some people never acquire these advanced skills. To master the smaller and more challenging tools that are used for embolization also takes a considerable time.
Embolization of haemorrhage is one of the most challenging tasks in vascular interventional radiology. In terms of how long these skills take to acquire, this will depend on the individual’s endovascular abilities. In terms of absolute numbers at least 50, and probably more than 100, embolization cases using microcatheters would be necessary to acquire the skills to perform embolization of haemorrhage, safely and effectively. To maintain these skills once learned, you would need to be doing between three and five embolization procedures a month. It is not just the catheter and guidewire skills that are essential, it is also the pattern recognition skills of small and large vessel arterial territories on CT angiography and catheter angiography and also the appearance of haemorrhage on these imaging modalities that need to be acquired and maintained.
Finally, embolization for haemorrhage in major trauma patients needs to be done as quickly as possible. Trauma patients usually have skeletal or other injuries that may require urgent surgical management after the bleeding has been stopped by embolization. Therefore, the interventionalist performing an embolization procedure in these critically ill patients needs to work under time pressures, with constant interruptions calling for the patient to be sent elsewhere for other procedures. In these situations, the interventionalist doing the embolization must be highly experienced and able to perform the procedure quickly and successfully under these difficult circumstances.
There is an understanding that non-IR specialties are undertaking simple embolization procedures, in some cases perhaps without adequate training…
I am aware that vascular surgeons undertake embolization in some abdominal arteries as a part of the EVAR (endovascular aneurysm repair) procedure and some surgeons also embolize endoleaks. Many vascular surgeons spend time working in interventional radiology departments, so that they are able to acquire the skills required in those situations. I would reiterate that I do not say for a minute that other specialties should not do those procedures, only that people need adequate training to do them safely and effectively.
As long as there is a recognition by doctors and also hospital administrators that certain procedures should be done by the specialty most suited in terms of training and experience to do them, embolization for haemorrhage will be performed successfully and with minimal procedural complications. In view of the extensive time that IRs spend in acquiring the skills required to use microcatheters and embolic agents, in the vast majority of hospitals IRs should be the specialists who are called upon to perform embolization for traumatic haemorrhage.
In many hospitals, the skills of interventional radiologists in trauma embolization are well-recognised and, as in my hospital, IRs are an important component of the protocols in place for the management of major trauma patients.
What are the key considerations when making the choice between embolization and surgery for traumatic haemorrhage?
- The condition of the patient—the patient may be in extremis and may be better off going straight to the operating room for surgery. The patient must be fit enough to come to the angiosuite for the embolization procedure, and anaesthetic support is usually required. Patients must be able to lie flat and immobile throughout the embolization procedure.
- Time is important. You need to have enough time to do the embolization procedure—patients with very rapid bleeding need immediate haemorrhage control and should be treated surgically.
- The area of haemorrhage that you want to embolize needs to be suitable for embolization, and not more suitable for treatment by any other cause; for example, somebody who is bleeding from a lacerated femoral artery requires surgery, and does not require embolization. Large vessel trauma requires surgery or endovascular stent grafting. Therefore, there is only a small subset of patients with traumatic haemorrhage who are actually suitable for, or require, embolization. Most of these patients will have sustained solid organ abdominal trauma, most commonly the spleen. Pelvic trauma often requires embolization, and occasionally the liver and kidney.
In summary, IRs have the requisite training and experience for the embolization of traumatic arterial haemorrhage and should be an integral part of the team involved in the management of trauma. National government agencies involved in healthcare provision should ensure that sufficient IRs are in place at each hospital that manages trauma to provide a comprehensive embolization service for these patients. Ensuring that there is sufficient cover by a well-staffed interventional radiology service is preferable to an ad hoc service provided by other non-IR clinicians, who seldom have the required skills, training or experience to perform embolization for these challenging and critically ill patients.