Merit Medical Supplement 2018: Transradial Embolotherapy

September 2018

E D U C AT I O N A L S U P P L E M E N T

THINK EDUCATION. ™ DISCOVER MERIT.

PARTNERING WITH US FOR YOUR PATIENTS – TRANSRADIAL EMBOLOTHERAPY

This educational supplement has been sponsored by Merit Medical.

This educational supplement has been sponsored by Merit Medical

Contents

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Microcatheters for prostatic artery embolization Attila Kovács, Bonn, Germany

Transradial access with HepaSphereTM Microspheres Darren Klass, Vancouver, Canada

Transradial fibroid embolization as a day-case procedure Mark Little, Reading, UK

Transradial access will be of paramount importance Bella Huasen, Preston, UK

Using the transradial approach in emergency embolization for trauma David Wells and Kader Allouni, Stoke-on-Trent, UK

MICROCATHETERS FOR PROSTATIC ARTERY EMBOLIZATION Attila Kovács of the Mediclin Robert Janker Clinic in Bonn, Germany, specialises in interventional radiology and neuroradiology. Here, he presents two cases in which the patient refused surgery.

Instead, microcatheters were used to perform prostatic artery embolization, using different techniques, strategies and microcatheters. The SwiftNINJA® and PursueTM microcatheters (both from Merit Medical) were utilised by Kovács in the following two cases.

Case 1: “Roundabout” prostatic artery embolization using the SwiftNINJA microcatheter

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67-year-old male patient with severe lower urinary tract syndrome (LUTS) and a markedly compromised quality of life presented for prostatic artery embolization (PAE).

The underlying pathology was an advanced benign prostatic syndrome (BPS). An additional prostatic malignancy could be ruled out by a slightly elevated prostate-specific antigen (3.5ng/ml) and an inconspicuous MRI. Symptoms had been refractory to medical therapy for over one year. The patient refused surgery for

religious reasons. Preinterventional MRI confirmed a slight left-sided dominance of the prostatic enlargement.

PAE was started with dominant left side.

Digital subtraction angiography revealed the absence of a direct vascular supply of the left prostatic lobe from the left side, but a mighty and winding collateral crossing to the right side (Fig 1). The SwiftNINJA microcatheter was able to pass all windings, simultaneously straightening the vessel (Fig 2). The tip of the SwiftNINJA was positioned at the origin of the

Patient

67-year-old male Benign pancreatic syndrome, no prostatic malignancy Severe lower urinary tract syndrome (International Prostate Symptom Score 27) refractory for medical therapy Not amenable for surgery for religious reasons (Jehovah's Witness) retrogradely supplying artery of the left prostatic lobe (single arrow). A protective coiling (double arrows) prevented the retrograde wash-out of the spheres into the paternal vessel on the right side. From this functional “wedge”-position, a safe embolization of the left prostatic lobe was carried out.

Fig. 1. The SwiftNINJA microcatheter at the origin of the tortuous collateral from

Fig. 2. The SwiftNINJA was advanced up to the origin of the supplying artery of the left

the left to the right side.

prostatic lobe (single arrow). Platinum coils (double arrows) were deployed to prevent the retrograde wash-out of the spheres into the paternal vessel on the right side

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Case 2: PErFecTED prostatic artery embolization using the Pursue TM microcatheter Patient

59-year-old male Benign prostatic syndrome without prostatic malignancy Severe lower urinary tract syndrome (International Prostate Symptom Score 21) refractory for medical therapy Patient refused surgery in order to preserve his sexual function

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Attila Kovács

59-year old, employed male patient with severe lower urinary tract syndrome (LUTS) and markedly compromised quality of life suffered predominantly from nocturia.

The underlying pathology was an advanced benign prostatic syndrome with a pronounced intravesical prostatic protrusion (IPP) causing a bladder outlet obstruction (BOO) refractory for medical therapy. A prostatic malignancy was ruled out in MRI. The patient refused surgery in order to preserve his sexual function.

Preinterventional MRI confirmed a left-dominant prostate spoiling the prostatic urethra to the right.

Prostatic artery embolization (PAE) was started with the dominant side on the left. Digital subtraction angiography revealed the prostatic artery (Fig 1). First an original prostatic artery embolization (oPAE) was performed from a proximal position. The oPAE is a flow-guided embolization—the blood stream carries the spheres towards the periphery. After reaching the endpoint of the oPAE, the stasis in the prostatic artery, the Pursue microcatheter was advanced further into the prostate to perform the second step: the embolization in the PErFecTEDtechnique (Fig 2).

The Pursue microcatheter is very flexible and allows for following successive tortuosities of the vessel, without the risk of spasm.

Fig. 1. Tip of the Pursue microcatheter (arrow) in the proximal position for the flow-guided oPAE

Fig. 2. Tip of the Pursue microcatheter (arrow) in the distal position for the PErFecTED embolisation from the wedge-position. Give attention how flexible the Pursue microcatheter follows the tortuosities of the prostatic artery.

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TRANSRADIAL ACCESS WITH HEPASPHERE TM MICROSPHERES Darren Klass (University of British Columbia; Vancouver, Canada) is a clinical associate professor of interventional radiology, specialising in interventional oncology, aortic intervention, peripheral vascular disease, venous disease, and venous access.

Here, he expands on his experience using transradial access with HepaSphereTM (Merit Medical).

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ercutaneous transradial access for angiography was first described in 1989.

It has been shown to be as efficacious as transfemoral access, as well as safer, more cost effective, and preferred by cardiology patients.

Radial access in interventional oncology has many advantages for both the patient and the operating team.

Lower complications demonstrated in cardiology are relevant to interventional radiology, particularly in patients with poor cardiorespiratory reserve or those patients with coagulopathies, frequently encountered in patients with liver dominant metastatic cancer and primary liver cancer.

The interventional radiology literature has increasing data demonstrating the safety and efficacy of transradial access with large retrospective cohorts published from Mount Sinai1 (New York, USA) and Vancouver General Hospital2 (Vancouver, Canada).

The use of transradial access in liver directed embolotherapy provides many advantages. Ease of cannulation of the visceral vessels and a more stable catheter platform within the target vessel as well as faster ambulation for the patient. The lower dose to both patient and operator was very elegantly demonstrated by Yamada et al3 in a randomised trial for transcatheter arterial chemoembolization (TACE).

Super absorbent polymer microspheres (HepaSphere; Merit Medical) have been used in our practice in Vancouver since 2012. We have studied it extensively, and published on its low adverse event profile and clinical efficacy.4 HepaSphere, due to its loading and design, is extremely compressible; it swells to four times the dry size when exposed to ionic environments, and thus packs the targets vessel on administration.

If administered correctly, a single vial is highly embolic, and therefore provides economic advantages over products requiring two vials per treatment. The favourable loading of HepaSphere5 allows it to be loaded within an hour and stored for up to 14 days.

The low side-effect profile and

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Darren Klass

economic advantages, coupled with the transradial technique, has allowed us to decrease the length of stay of patients post procedure considerably, thus decreasing the pressure on inpatient beds in our institution. Eighty-five per cent of our patients are discharged on the same day following a TACE procedure, including those patients undergoing lobar TACE with appropriate liver function. This shift in care has allowed us to perform TACE late in the day without the risk of an access site bleed, particularly in those patients with coagulopathy. This provides us with the flexibility to triage patients according to clinical need during the day and not cancel patients late in the day, as was our experience with transfemoral TACE, due to the need for prolonged nursing care. Our rapid deflation protocol (PROTEA) using a haemostatic patch (Statseal, Biolife) has further decreased the nursing intensity required post procedure.6 A further addition to our practice has been left distal access (ldTRA), which has provided even faster deflation times, almost half that of PROTEA using a rapid ldTRA protocol (dPROTEA). Our initial data will be presented at CIRSE 2018.

In 2014, we transitioned to the smaller HepaSphere size (30–60µm) from the larger particle (50–100µm).

We have compared the outcomes of our experience with the 50–100µm as well as other proprietary loadable beads

available in Canada,7 and HepaSphere showed consistently higher disease control rates. We have subsequently compared this data to our experience with HepaSphere 30–60µm, which has further demonstrated improved disease control rates. One of the hypotheses is that due to the compressibility of the microsphere, the effective 120–240µm size compresses into smaller vessels, providing a better embolic effect.

The stability of the bead once loaded decreases the systemic release of the doxorubicin, which is one of the many factors contributing to the low adverse events demonstrated.4 The addition of 20–40µm HepaSphere is an exciting prospect given its loaded size will effectively be 80–120µm, potentially providing a better locoregional effect.

We will undoubtedly study this microsphere, as we have with the former in order to better understand the complex science behind tumour biology and embolic efficacy.

Transradial embolization using HepaSphere provides good clinical efficacy and allows for same day discharge. This, coupled with the lower volume of embolic required to achieve stasis, provides both clinical and economic advantages. We all have to take a step back and remember we are treating patients with a non-resectable disease, and that any technique we can employ to decrease the amount of time they need to spend in hospital, taking precious time away from loved ones, is priceless.

Darren Klass is an interventional radiologist with Vancouver Coastal Health and Vancouver Imaging in Vancouver, Canada.

References: 1. Posham R, Biederman DM, Patel RS, et al. Transradial Approach for Noncoronary Interventions: A Single-Center Review of Safety and Feasibility in the First 1,500 Cases.

JVIR 2016 Feb;27(2):159–66.

2. Thakor AS, Alshammari MT, Liu DM, et al. Transradial Access for Interventional Radiology: Single-Centre Procedural and Clinical Outcome Analysis. CARJ 2017 Aug;68(3):318–327.

3. Yamada R, Bracewell S, Bassaco B, et al. Transradial Versus Transfemoral Arterial Access in Liver Cancer Embolization: Randomized Trial to Assess Patient Satisfaction. JVIR 2018 Jan;29(1):38–43.

4. Klass D, Owen D, Buczkowski A, et al. The effect of doxorubicin loading on response and toxicity with drug-eluting embolization in resectable hepatoma: a dose escalation study. Anticancer Res. 2014 Jul;34(7):3597–606 5. Liu DM, Kos S, Buczkowski A, et al. Optimization of doxorubicin loading for superabsorbent polymer microspheres: in vitro analysis. CVIR 2012 Apr;35(2):391–8.

6. N De Korompay, J Chung, S Ho, et al. Safety and efficacy of a rapid deflation algorithm for patent hemostasis following radial intervention (PROTEA) JVIR 2017 (28)2:S131 7. Co SJ, Peixoto R, Ho S, et al. Retrospective analysis of 70–100um compared to 100–300um or 50–100um HepaSphere Doxorubicin drug eluting bead embolization in patients with non-resectable hepatocellular carcinoma: Preliminary results. Abstract 3109.6 CVIR 2013 Sept;36 Suppl 3:S251

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TRANSRADIAL FIBROID EMBOLIZATION AS A DAY-CASE PROCEDURE Mark Little is a consultant interventional radiologist at the Royal Berkshire NHS Foundation Trust, Reading, UK, and lectures in Anatomy and Embryology at Keble College, University of Oxford. In this interview, he discusses transradial access for uterine fibroid embolization, and his conviction that this approach benefits patients by providing greater autonomy and dignity, as well as a swifter pathway to recovery.

What led you to undertake the transradial approach for uterine artery embolization?

My aim was to establish a pathway to give patients the option to undergo this procedure as a day-case procedure.

Individualised patient care is crucial to achieve this. I see all my patients in a dedicated fibroid clinic with a specialist embolization nurse. In addition to discussing the indication and risks with my patients, I take time to explain what to expect during the procedure and during recovery. The key driver towards a transradial approach has been to allow patients to mobilise immediately after the procedure. There is certainly a psychological benefit to not having to lie flat for two hours, and patients have found it more comfortable to be able to sit or lie in a position they find most comfortable, minimising pain and enabling a day-case pathway. Patient feedback has revealed that a transradial approach is extremely well tolerated, with greater patient autonomy and preservation of dignity compared to the femoral approach.

Could you comment on your experience with the procedure?

Like most operators, I previously performed uterine artery embolization for a number of years from the traditional femoral approach. The Royal Berkshire NHS Foundation Trust has long been at the vanguard of techniques for uterine artery embolization. Since becoming one of the early adopters of this procedure at the end of the last century, we have performed over 1,000 cases. I transitioned to transradial access for the

procedure last year, having been convinced of the benefits of greater patient choice.

What have the results been so far?

The results have been fantastic!

The procedure is technically straight-forward from a left radial artery puncture, enabling fast procedural times and consequently low radiation dose to patient and operator.

The closure of the radial arteriotomy is straightforward using the Safeguard RadialTM Compression Device (Merit Medical).

How do you select patients for this approach?

I take a lot of time in clinic explaining the procedure, and discuss both the femoral and radial access routes. Ultimately it is down to patient choice.

However, I particularly favour a radial approach for patients with high body mass index (BMI), and also find that recovery is faster in our interventional radiology recovery unit, which is one of the factors permitting a day-case pathway.

What are the benefits that patients have seen with this approach?

Patients like the fact that they can sit up straight after the procedure, and many find that this helps reduce abdominal discomfort that arises following embolization. Patients are able to move around and find the most comfortable position without the fear of bleeding from the groin.

What is the pain protocol that you use?

We have been using intra-arterial lidocaine following embolization with good analgesic effect. We

are also working closely with our anaesthetic colleagues and have created a dedicated oral analgesia protocol permitting a day-case uterine artery embolization pathway.

I would recommend anyone practicing this procedure to spend some time with the pain specialists in their institution to develop a specific analgesic regimen for these patients. I think analgesia and sedation in interventional radiology will be another important area of development in the coming years.

Do you have any tips or tricks regarding performing uterine artery embolization using the transradial approach?

Like all of interventional radiology, getting in and getting out are the most important steps.

I always take time to scan the full length of the radial, brachial and axillary arteries using ultrasound. I look for variant anatomy and radial loops that can complicate access. I perform a Barbeau test to ensure patency of the deep palmar arch prior to puncture. It is important to infiltrate glycerine trinitrate and lidocaine around the distal radial artery, to vasodilate the vessel and provide analgesia. I will then haemodilute 2.5mg Verapamil, 200mcg glycerine trinitrate and 2,000IU heparin in a 20ml syringe, which is then slowly injected into the radial artery through the sheath to minimise spasm.

I use a hydrophilic guidewire and Berenstein catheter (Merit Medical) to engage the anterior division of the internal iliac arteries. It is important to visualise the passage of wire and catheter from the left subclavian artery into the descending

Mark Little

thoracic aorta, to ensure that the left vertebral artery or common carotid are not selected.

Embolization is performed using 500–700micron Embosphere® Microspheres through a microcatheter in the standard way. I leave space at the end of embolization to inject 1% lidocaine into the uterine artery for analgesia. The dose of lidocaine is calculated from the patient’s weight, and the amount already infiltrated prior to arterial puncture.

Do you have all the tools that you require in order to perform this procedure with the transradial approach?

We are routinely performing transradial uterine artery embolization at the Royal Berkshire NHS Foundation trust, and the programme continues to grow. Embracing transradial access has provided my colleagues and myself with an additional access option; consequently, I have performed a range of interventions with a radial approach.

We are now moving to transradial access for our prostate artery embolization programme.

Because of the increasing number of patients we are treating, there is an immediate need for longer catheters—particularly in taller men having prostate artery embolization.

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TRANSRADIAL ACCESS WILL BE OF PARAMOUNT IMPORTANCE Bella Huasen is a clinical radiologist with a subspecialty interest in vascular interventional radiology at the Royal Preston hospital (Preston, UK). Huasen speaks to Interventional News about her experiences attending Merit Medical training courses, highlighting the transformative impact this education has had on her patient care.

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ith recent limitations to education funds—whether via industry sponsorship or directly through the NHS—educational courses, such as those run by Merit Medical, have become a major source of continued educational development and an increasingly important route for the introduction of new services to healthcare systems around the world.

Whilst a consultant interventional radiologist and throughout my endovascular training, Merit Medical has flourished in its variety of educational courses. A wide range of dates has been made available to cater for busy schedules and on-going conferences. Course content (including topics such as prostate embolization, radial access, fibroid embolization, transarterial chemoembolization), course organiser names and the meeting location are all made available to clinicians in a yearly timetable to allow for advance planning. The speakers and course organisers are always the elite of their field, and a wide range of educational methods are used to deliver content, supporting different learning methods and techniques.

The radial access course I attended during my final year of training was one of the best hands-on courses I have experienced. The quality of cadavers used to practice radial access was second to none. I was very fortunate to have one-toone teaching from interventional radiology consultant Darren Klass (Vancouver, Canada); during this course, he was kind enough to share his tips and tricks, and, most importantly, troubleshooting techniques, especially when starting up this service. The hand-outs were fantastic, and included forms that can be used to start up the service in your own department (such as monitoring, recording and dosage of drugs used, and wrist band air release advice). A lot of useful information was provided which was of great help for those in need of a business case to

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Bella Huasen

start up this service. I met an amazing group of colleagues there who remain close friends to this day, and now form part of my close network of interventional radiology advisors.

You would be amazed at the level of skill and knowledge of some of the attendees, meaning that not only do you learn from the organisers, but also from the wealth of knowledge the attending colleagues bring to the course.

We had a star guest appearance from the pioneer and father of transradial access, Ferdinand Kiemeneij (Amsterdam, The Netherlands), who shared the story behind the development of this vascular access method, and how it became the gold standard technique for the endovascular management of cardiac patients. His passion for this technique, the hard work and effort that went into developing catheters and sheaths to cater for safety and ease, and his ability to transform what was initially a local project

into an international trend was truly inspiring!

I would say transradial access has made a dramatic impact on my fibroid embolization patients. The transfemoral access procedure can be, at times, uncomfortable even with good analgesia and nerve block.

So patients find it empowering; the ability to move around with only a wristband to consider, especially those who have had in the past groin puncture to compare it to. This access has become my first approach for these patients, and often I get asked to “go through the wrist not the groin please”.

Most of my colleagues and senior consultants use a transradial approach for many embolization procedures such as transarterial chemoembolization, prostate and mesenteric work. I have only been taught the transradial approach for transarterial chemoembolization and cannot imagine doing it differently.

With the rapid and constant development in both medical systems and medical techniques, I believe transradial access will be of paramount importance to any clinician working in the endovascular field. I would highly recommend this Merit Medical course to any colleague who has not started up the service, is about to start up, or would like more tips and tricks to develop their skills.

This also applies to the entire Merit course portfolio available each year.

For those who have not considered nerve blocks in fibroid embolization, I would highly recommend attending this course: with live cases on the day, you are able to directly see the impact this technique has on patient care.

I hope Merit continues running these courses, and continues to take into account our feedback so future generations can benefit from the knowledge and skills out there as I have. Who knows—maybe the future Darren Klass or Ferdinand Kiemeneij can be inspired by these courses, and a new star will be born with a new idea to improve and transform our health care offering!

Bella Huasen is an interventional radiology consultant at the Lancashire University teaching Hospitals in Preston, UK

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USING THE TRANSRADIAL APPROACH IN EMERGENCY EMBOLIZATION FOR TRAUMA In this interview, David Wells and Kader Allouni, both consultant interventional radiologists at the University Hospitals of North Midlands NHS Trust in Stoke-on-Trent, UK, speak to Interventional News about the benefits of using the transradial approach during emergency embolization procedures in trauma patients.

Why is emergency embolization for trauma important, and why is the transradial approach a good fit for this procedure?

Interventional radiology has emerged as a fundamental part of modern trauma services. Embolization in trauma and other life-threatening haemorrhagic situations can be the definitive treatment or a precursor or adjunct to formal open surgery; this is best exemplified in splenic trauma.

The transradial approach is wellsuited to these cases for a number of reasons. Trauma patients are often in a pelvic binder, which would need to be removed for femoral access.

Transradial access allows the binder to stay on, maintaining pelvic stability.

This patient group often has some kind of coagulopathy, which would make the risk of a groin access site complication relatively high. The diameters of transradial catheters are suitable for delivering a range of embolics—coils, gel foam, liquid embolics, or even microvascular plugs.

Indeed, some covered stents can be delivered given a large enough radial artery. Treatment goals are to stabilise the patient either as the definitive treatment or as a precursor or adjunct to formal surgery.

What factors would lead you to make the treatment decision to go down the radial route?

Elective patients select themselves!

Women prefer the freedom of movement post uterine fibroid embolization (UFE), as do men after prostate artery embolization (PAE).

Emergency haemorrhages are ideal for a transradial approach, because the anatomy is so much easier to navigate from above. In selecting transradial candidate patients, the operator must ensure that catheters are going to be long enough (distal branches of the IIA are difficult to reach in individuals over 6ft tall, or 183cm) and wide enough to deliver your chosen embolic.

If a covered stent is to be used, to exclude a false aneurysm, for example, then careful planning is required to ensure diameters will be suitable; a

centre. Numbers are small at present, but increasing rapidly, with 100% success so far.

What are the advantages or benefits that patients have seen with this approach?

David Wells

Unlike in the elective setting, the trauma/emergency patient is routinely oblivious to the route of access chosen and are unlikely to benefit from early mobilisation. The benefits are really from the reduced procedural time and reduced dose to patients and operators. Our data in a forthcoming publication shows that the transradial approach can provide as much as a five-fold reduction in radiation dose when compared with a transfemoral approach. Some of this benefit arises from a significantly shorter procedural time.

Are there any complications that you have observed due to the radial approach in this procedure?

We have not observed any complications related to the route of access itself, but we note one case of transient heart block secondary to verapamil administration. We have subsequently reduced the dose of verapamil used and are vigilant when infusing slowly.

Kader Allouni

sheathless guide catheter might need to be used. So selection is based on reviewing imaging, assessing the patient, and planning the procedure to ensure the operator can reach the target and deliver what needs to be delivered successfully at the target site.

Could you share the result of you experience so far?

The vast majority of our transradial experience has come from elective embolization cases: uterine fibroid embolization and prostate artery embolization. However, now that our interventional radiology team is familiar with the technique, we have begun to routinely use the transradial approach for selective trauma and emergency cases at our major trauma

What are the key learnings from performing transradial emergency embolization?

The main one is the importance of communication. Informing the trauma team and anaesthetists to not use the left arm for arterial lines or pressure cuffs.

The anaesthetist also needs to be made aware of the use of glyceryl trinitrate and verapamil, both of which may have cardiac effects.

Experience is also important.

Although the transradial approach seems to be a natural progression for the interventional radiologist operator, the drugs used and the concept itself is often a challenge for nursing staff. A good programme of shared education within the interventional radiologist department and experience in the elective setting should be advocated before emergency cases are attempted.

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