Purpose Drainage catheters allow fluid to be released from collections and structures. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here
Essential equipment Embolotherapy is the deliberate blockage of blood vessels; embolization may be lifesaving when used to stop haemorrhage. Embolization is increasingly used as an adjunct to surgery and in the treatment of a variety of benign and malignant tumours. Many embolic agents are available to block vessels of different sizes, from large arteries to capillaries. The choice of the agent used depends on the individual…
Purpose Inferior vena cava (IVC) filters are placed to prevent pulmonary embolism. They are most often used when there is a contraindication to anticoagulation. Despite the name, they are occasionally used in the superior vena cava. Description IVC filters use a form of wire lattice, often umbrella-shaped, to catch large blood clots, while allowing flow through the inferior vena cava. They are introduced in a constrained…
Purpose Covered stents provide an impermeable conduit and are used in both the vascular and non-vascular system. In the vascular system, they are called ‘stent grafts’. Vascular The most important indications are treating aneurysms and arterial rupture. Other indications are TIPS and in certain circumstances to manage stenotic and occlusive disease. Non-vascular Outside the vascular world, they tend to be called ‘covered stents’. In the majority…
Purpose Stents are scaffolds used to maintain luminal patency in many systems, e.g. vascular, biliary, gastrointestinal and tracheobronchial. They act by exerting an outward radial force to overcome stenoses/occlusions and elastic recoil after angioplasty. Stents may also reduce the likelihood of distal embolization during angioplasty by trapping plaque/thrombus against the vessel wall. Description Stents comprise a metal strut latticework, they have a high expansion ratio allowing…
Purpose The only way to be certain a balloon is being used at the correct pressure is to use an inflation handle with a pressure gauge ( Fig. 19.1 ). Besides precision, the inflation handle allows you to effortlessly generate and sustain high pressures without hurting your skilled hand. Description These are modified syringes, the plunger is driven into the syringe barrel with a screw thread…
Purpose of equipment These are mostly used to dilate blood vessels but can be equally useful for strictures in other systems. Description Although there is a huge variety of different angioplasty balloons, they all boil down to a straight catheter with an inflatable balloon at the distal end. All angioplasty balloons have a channel for a guidewire and a separate channel to allow balloon inflation There…
Purpose Snares are essentially wire loops, which are used to capture/manipulate/remove wires, catheters and various other ‘foreign bodies’. Description All snares are variations on the good old cowboy lasso, in other words, they have a loop that can be rotated and manoeuvred onto a target and then tightened by advancing a catheter to close the loop. Simple single-loop lasso design The nitinol Amplatz GooseNeck snare is…
Purpose Even the strongest angiographer cannot hand inject rapidly enough for aortic runs. Pump injectors are used to deliver a rapid controlled bolus of contrast while you stand back and reduce your radiation dose. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here
Taps Purpose Just as with domestic taps, these are turned on and off to control flow and there is even a mixer version. Description Only two types of tap are of importance but there are some important caveats: Two-way taps These taps have two positions – on and off – they are often used on the end of connecting tubes. Two-way taps come in two styles:…
Sheaths and guide-catheters are designed to allow the coaxial passage of other devices. There is overlap between the structure and function and recently, introducer guides have developed as a crossover group. There are differences in sizing and usage, so the devices will be discussed separately. Sheaths Purpose Sheaths act as atraumatic access conduits for other equipment. There are two main designs: the vascular access sheath and…
Purpose Microcatheters allow catheterization and delivery of embolic material to the smallest and most tortuous of vessels ( Fig. 13.1 ). Microcatheters are ideal for super-selective hepatic, visceral and peripheral catheterization. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here
Purpose Non-selective catheters with multiple sideholes are used for rapid injection of contrast into large–medium-sized arteries. Selective catheters may have sideholes or just a single endhole; they are shaped to allow the catheter to enter branch vessels or direct guidewires into them. Description Catheters come in a wide range of shapes, sizes and constructions. Simple rules govern catheter choice. Most interventional radiologists rely on a relatively…
Purpose Guidewires are used in conjunction with catheters to navigate to a target, in addition they provide support and in the majority of cases, catheters, balloons and other devices are advanced into position over a previously positioned wire. Nearly all guidewires are constructed with a relatively flexible tip section of variable length and a less flexible shaft of variable stiffness. The performance of a guidewire depends…
Purpose An access kit allows the least traumatic (i.e. smallest) initial needle puncture of the target and provides a method to convert the 22G puncture to standard 0.035-inch guidewire access. Description A typical set comprises: A one- or two-part 22G needle for the initial puncture A short 0.018-inch guidewire with flexible tip and supportive shaft An interlocked dilator system. This varies from kit to kit. Those…
Purpose The ideal biopsy needle provides a diagnostic tissue sample at the lowest possible risk. Description Needles are usually characterised by their mechanism of action into aspiration and core biopsy needles. Aspiration needles Purpose To safely provide a sample of a few cells for cytological, biochemical and microbiological analysis. Cytology can be enough to confirm malignancy but doesn't give any “architectural” information. Description Most aspiration samples…
Purpose Puncture needles are vital for getting from the skin to the target as a prelude to access with a guidewire, aspiration of fluid or placement of a drain. Not all needles are equal and you need to know what to request. Description You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member.…
Outpatient clinics are an essential component of contemporary practice. Some interventional radiologists have held outpatient clinics for many years but for others, this will be a new experience. The functions of the clinic should simply be extensions of various aspects of daily practice. The challenge of the clinic is to deliver this in time-limited encounters. Broadly speaking, the roles of the clinic can be understood as…
Oh dear, we are still in the introductory section and already complications are rearing their ugly heads. One thing is certain, during a career in interventional radiology, there will be cases which do not follow the script. There are of course many things that can and do go wrong. Your job is to: Minimize predictable/preventable errors Recognize problems as early as possible Limit damage to the…
Pain control – forward planning Many interventional radiology procedures do not require any analgesia; some procedures are intrinsically painful, especially if they are prolonged, and others are unpredictably uncomfortable. The procedure will be simpler and the patient less distressed if pain can be kept to a minimum; they will be even happier if pain can be avoided altogether. Preventing severe pain is likely to increase everyone's…