Glossary

Angiography

Angiography is the x-ray study of the blood vessels. An angiogram uses a radiopaque substance, or dye, to make the blood vessels visible under x ray. Arteriography is a type of angiography that involves the study of the arteries.

Angioplasty

The technique of mechanically widening narrowed or obstructed arteries. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size. The balloon forces expansion of the inner white blood cell/clot plaque deposits and the surrounding muscular wall, opening up the blood vessel for improved flow, and the balloon is then deflated and withdrawn. A stent may or may not be inserted at the time of ballooning to ensure the vessel remains open. 

Balloon Occlusion

The temporary stoppage of blood flow through a major blood vessel can be achieved by balloon occlusion. A flexible tube (catheter) with a balloon attached to its tip is inserted into the blood vessel, positioned appropriately and when the catheter is in the correct position, the balloon is filled with saline. As the balloon expands it blocks the blood vessel. With the vessel blocked, the surgery can be performed. After the surgery, the balloon and catheter are removed and the blood flow is restored. 

Computed Tomography Scanning

A medical imaging procedure that utilizes computer-processed X-rays to produce tomographic images or 'slices' of specific areas of the body. These cross-sectional images are used for diagnostic and therapeutic purposes. Digital geometry processing is used to generate a three-dimensional image of the inside of a patient from a large series of two-dimensional X-ray images taken around a single axis of rotation. 

CT Angiography

A computed tomography technique used to visualize arterial and venous vessels throughout the body. This ranges from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs. 

Digital Subtraction Angiography

A computer-assisted x-ray technique that subtracts images of bone and soft tissue to permit viewing of the cardiovascular system. 

Endovascular Surgery

A form of minimally invasive surgery that was designed to access many regions of the body via major blood vessels. Endovascular techniques were originally designed for diagnostic purposes. Basic techniques involve the introduction of a catheter percutaneously or through the skin, into a large blood vessel. Typically the blood vessel chosen is the femoral artery or vein found near the groin. Access to the femoral artery for example, is required for coronary, carotid, and cerebral angiographic procedures. The catheter is injected with a radio-opaque dye that can be seen on live X-ray or fluoroscopy. As the dye courses through the blood vessels, characteristic images are seen by experienced viewers and can assist in the diagnosis of diseases such as atherosclerosis, vascular trauma, or aneurysms. In recent years, however, the development of intravascular balloons, stents and coils have allowed for new therapies as alternatives to traditional surgeries such as coronary artery bypass surgery (CABG), carotid endarterectomy and aneurysm clipping. Stents and coils are composed of fine wire materials such as platinum that can be inserted through a thin catheter and expanded into a predetermined shape once they are guided into place. Endovascular surgery is performed by radiologists, neurologists, neurosurgeons, cardiologists, and vascular surgeons. The field is rapidly growing as its minimally invasive techniques offer an immediate advantage over more traditional, yet highly invasive surgeries. 

Fluoroscopy

An imaging technique that uses X-rays to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an X-ray source and fluorescent screen between which a patient is placed. However, modern fluoroscopes couple the screen to an X-ray image intensifier and CCD video camera allowing the images to be recorded and played on a monitor. Recent advances include the digitization of the images captured and flat panel detector systems which reduce the radiation dose to the patient. 

Forward Resuscitative Surgery

The urgent initial surgery required to render a patient transportable for further evacuation to medical treatment facilities staffed and equipped to provide for their care. Forward resuscitative surgery is performed on patients with signs and symptoms of initial airway compromise, difficult breathing, and circulatory shock and who do not respond to initial emergency medical treatment and advanced trauma management procedures. 

Hybrid Procedure

A newer adaption of Endovascular Aneurysm Repair, or Endovascular Aortic Repair (EVAR). A hybrid procedure generally occurs in the angiography room and aims to combine endovascular procedures with limited open surgery. In this procedure the stent graft deployment is planned to combine with an open operation to revascularize selected arteries that will be "covered" by the stent graft i.e. deprived of arterial inflow. In this method more extensive EVAR devices can be deployed to treat the primary lesion while preserving arterial flow to critical arteries. 

Hemorrhage Control

Steps or actions taken to control bleeding from a patient who has suffered a traumatic injury or who has a medical condition which has led to bleeding. 

Introducer

A short plastic tube placed within a vein or artery, through which various catheters are passed for local or central diagnostic or therapeutic interventions. 

Ischemia Reperfusion Injury

Tissue ischemia (restriction in blood supply) with inadequate oxygen supply followed by successful reperfusion (restoration of blood supply) initiates an array of inflammatory responses that may both aggravate local injury as well as induce impairment of remote organ function. Conditions under which ischemia-reperfusion injury is encountered include the different forms of acute vascular occlusions (stroke, myocardial infarction, limb ischemia) with the respective reperfusion strategies (thrombolytic therapy, angioplasty, operative revascularization) but also routine surgical procedures (organ transplantation, free-tissue-transfer, cardiopulmonary bypass, vascular surgery) and major trauma/shock. 

Magnetic Resonance Imaging

A medical imaging technique used in radiology to visualize internal structures of the body in detail. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body. MRI can create more detailed images of the human body than possible with X-rays. An MRI scanner is a device in which the patient lies within a large, powerful magnet and information is recorded to construct a 2D or 3D image of the scanned area of the body. MRI provides good contrast between the different soft tissues of the body, which makes it especially useful in imaging the brain, muscles, the heart, and cancers compared with other medical imaging techniques such as computed tomography (CT) or X-rays. Unlike CT scans or traditional X-rays, MRI does not use ionizing radiation. 

MR Angiography

A group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of the arteries in order to evaluate them for stenosis (abnormal narrowing), occlusion or aneurysms (vessel wall dilatations, at risk of rupture). MRA is often used to evaluate the arteries of the neck and brain, the thoracic and abdominal aorta, the renal arteries, and the legs.  

Proximal Control

The basic principle of vascular repair is to gain proximal and distal control of the relevant vessel before investigating the site of injury. Direct exploration of a wound that is actively bleeding will inevitably lead to failure to control the hemorrhage and collateral damage to neighboring structures. Proximal control is best achieved through a separate incision away from the site of injury. Distal control similarly is best achieved via a second incision. Once proximal and distal control is achieved, the site of injury can be explored and control made closer to the injury site. It may be tempting to directly explore a wound that is not actively bleeding. However, profuse hemorrhage can rapidly obscure the operative field once clot is dislodged from around the site of vascular injury.

RAPTOR Suite

Resuscitation with Angiography, Percutaneous Techniques and Operative Repair (RAPTOR) suites are becoming available in a small number of centers. These suites allow emergent percutaneous therapies to be performed in the same physical location as open interventions, resuscitation and critical care, preventing the need for transfer of patients from one venue to another (trauma bay v. operating theatre v. angiography suite v. intensive care unit). RAPTOR suites offer the ability to treat all aspects of a patient’s critical injury (i.e., fixed angiography system, operating room, interventional radiology suite and intensive care unit). 

Seldinger Technique

A method to obtain safe access to blood vessels and other hollow organs. It is named after Dr. Sven-Ivar Seldinger (1921-1998), a Swedish radiologist who introduced the procedure in 1953. The desired vessel or cavity is punctured with a sharp hollow needle called a trocar, with ultrasound guidance if necessary. A round-tipped guide wire is then advanced through the lumen of the trocar, and the trocar is withdrawn. A "sheath" or blunt cannula can now be passed over the guide wire into the cavity or vessel. After passing a sheath of tube, the guide wire is withdrawn. If a sheath is used, it can be used to introduce catheters or other devices to perform endoluminal procedures, such as angioplasty. Fluoroscopy may be used to confirm the position of the catheter and to maneuver it to the desired location. Injection of radiocontrast may be used to visualize organs. Interventional procedures, such as thermoablation, angioplasty, embolization or biopsy, may be performed. Upon completion of the desired procedure, the sheath is withdrawn. 

Sheath

A tool that consists of a tube that is inserted into the body to provide an access point to allow the insertion of other instruments into an artery. The introducer sheath is used during percutaneous procedures such as angiography, angioplasty and stent placement. After the procedure, the introducer sheath is removed. 

Stent

An artificial 'tube' or metal mesh inserted into a vessel in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow access for surgery. 

Stent Graft

A tubular device, which is composed of special fabric supported by a stent. Usually a stent has no covering. Stent grafts are used mainly for vascular intervention and endovascular surgery. Stent grafts are used to support weak points in arteries, commonly known as aneurysms, and are most commonly used in the repair of an abdominal aortic aneurysm, in a procedure called an Endovascular Aneurysm Repair, or Endovascular Aortic Repair (EVAR). Once in place inside the aorta, the stent graft acts as a false lumen for blood travel through, instead of pooling in the aneurysm sack. 

Vascular Surgery

A specialty of surgery in which diseases of the vascular system, or arteries and veins, are managed by medical therapy, minimally-invasive catheter procedures, and surgical reconstruction. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system except that of the heart and brain. Cardiothoracic surgeons manage surgical disease of the heart and its vessels. Neurosurgeons manage surgical disease of the vessels in the brain (e.g. intracranial aneurysms). 

Wire

A long and flexible fine spring used to introduce and position an intravascular angiographic catheter