INTERVENTION RADIOLOGY

INTRODUCTION

Interventional radiology (IR) is a medical subspecialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices.

Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct.

In therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement (e.g., stents), and angioplasty of narrowed structures.

Diagnostic interventional radiology

Angiography: Imaging the blood vessels to look for abnormalities with the use of various contrast media, including iodinated contrast, gadolinium based agents .

•Cholangiography: Imaging the bile dcts within the liver to look for areas of blockage.

•Biopsy: Taking of a tissue sample from the area of interest for pathological examination from a percutaneous or transvenous approach.

Therapeutic interventional radiology

Vascular

•Balloon angioplasty/stent: Opening of narrow or blocked blood vessels using a balloon, with or without placement of metallic stents to aid in keep vessel patent.

•Endovascular aneurysm repair: Placement of endovascular stent-graft across an aneurysm to prevent expansion or progression of the defective vessel.

•Embolization: Placement of a metallic coil or embolic substance (gel-foam, poly-vinyl alcohol) to block blood through to a blood vessel, either to stop bleeding or decrease blood flow to a target organ or tissue

HISTORY OF IR

In 1953 Swedish doctor Svenlvar Seldinger introduced Seldinger technique which laid down the foundation of IR.

In 1963, Charles Dotter first proposed the idea of IR (The father of IR)

In 1964, Charles Dotter done percutaneous angioplasty through accidental operation.

Endovascular stent was proposed in 1969.

Percutaneous coronary angioplasty is applied in 1977.

TIPSS started from 1986. Charlse Dotter.

PRINCIPLE

What is Seldinger technique?

Seldinger technique is the medical procedure to obtain safe access to the blood vessel and other hollow organs…

HISTORY

IN 1953, SVEN IVAR SELDINGER PUBLISHED A METHOD FOR PERCUTANEOUS ARTERIAL CATHETERISTION THAT OPENED THE DOORS TO THE FIELD OF ANGIOGRAPHY & INTERVENTIONAL RADIOLOGY.

Seldinger technique for introducing catheters

•  This technique allows entry into an area without a cut down and because small gauge needles are used .

•   There is minimal trauma to surrounding tissues.

Less pain and faster recovery

Equipements

  • Seldinger needle
  • Guide wire
  • Dilator
  • Sheath /Catheter

TECHNIQUE

•Insert needle into vessel

Stabilize needle.

• Stabilize needle with the other hand to prevent it from dislodging .

• Advance wire into vessel

Remove needle and wire cover.  The guide wire needs to be securely held during the procedure to limit further advancement into the vessel, Advanced dilator over the wire 1 to 1 half inches into the insertion point and rotate back and forth . Remove dilator. Advanced sheath/ catheter over the guide wire into the vessel, Remove guide wire . Flush and secure catheter to skin with sutures.. Wrap to provide additional stabilization.

SELDINGER NEEDLE

Mostly used 18 gauge angiographic needle

Guide wire is introduced directly through the needle

Advanced dilator over the wire 1 to 1 half inches into the insertion point and rotate back and forth .

Remove dilator.

Advanced sheath/ catheter over the guide wire into the vessel  Remove guide wire . Flush and secure catheter to skin with sutures..  Wrap to provide additional stabilization.

PREPARATION

IR SUIT

• Specifically designed to accommodate the quantity of equipment needed & the large number of people involved in the procedure Personnel in the IR room , Interventional Radiologist ( or other specialist)

Radiologic Technologists , Nurse , Sometimes Anesthesiologist depending on the procedure.

Prepare Room/ consent forms

•Provide radiographic positioning /Dr assistance

•Knowledge of exam, anatomy, pathology

•Prepare sterile tray, prep patient

•Knowledge of catheters and guide wires

•Know sterile technique/ safe clean up

•Monitor ECG + pressure

•Patient care skills and pharmacology

EQUIPMENT

Seldinger needle

• Mostly used 18 gauge angiographic needle .

• Guide wire is introduced directly through the needle .

Guide wire

It’s a long and flexible ,fine metal wire.

•They are the stainless steel metallic structures that guides the catheter through the blood vessels for placements. 

•Guide wires are used for interventional procedures .

Catheter

•Catheter is a tubular, thin ,flexible instrument

•It can be inserted into a body cavity, duct or vessel.

•Functionally ,they allow drainage , administration of fluid or gases, access by surgical instruments diameter is given in French(Fr)—3Fr=1mm

COMMON IR PROCEDURE

  • Angiography
  • Angioplasty (balloon /stent)
  • Ablation
  • Biliary intervention
  • Biopsy ,Cholecystostomy
  • Drain insertions 
  • Endovascular aneurism
  • Endovenous laser treatment
  • Embolization
  • IVC filters
  • Nephrostomy ,Radiologically inserted gastrostomy —
  • Thrombolysis
  • Vertibloplasty

IMAGING MODALITIES

  • Fluoroscopic unit
  • Computed Tomography (CT)
  • Ultrasound
  • Magnetic Resonance Imaging

APPLICATION

ANGIOGRAM

Imaging the blood vessels to look for abnormalities with the various contrast media

HISTORY

The first angiogram was performed only months after Roentgen’s discovery of X rays. Two physicians injected mercury salts into an amputated hand and created an image of the arteries Postmortem injection of mercury salts in Jan,1896.

ANGIOPLASTY

Opening of narrow or blood vessels using a balloon, may include placement of metallic stents as well.

ABLATION

Radiofrequency ablation (RF/RFA) localized destruction of tissue (e.g., tumours ) by heating. Cryoablation localized destruction of tissue by freezing &Microwave ablation localized destruction of tissue by heating.

ANEURISM

Aneurism is a localized , blood filled balloon like bulge in the wall of blood vessels.

Aneurism can occur in any blood vessels

Minimally invasive techniques have been developed for many types of aneurism.

BRAIN INSERTIONS

Placements of tubes into different parts of the body to drain fluids (e.g. abscess drain to remove pus, pleural drains)

BIOPSY

Taking a tissue sample from the area of interest for pathological examination from a percutaneous apprroch.

CHOLECYSTOSTOMY

Placement of a tube into the gallbladder to remove infected bile in patients with cholecystitis: an inflammation of gallbladder , who are too frail or too sick to undergo surgery

EMBOLISATION

Embolisation is a way of blocking abnormal blood vessels(to stop the extra function).  Various substances can be used to block the blood vessels, including medical glue, medical putty, tiny metal coils or plastic beads.

NEPHROSTOMY

Placing a catheter directly into the kidney to drain urine in situations where normal flow of urine obstructed.

RISK/COMPLICATION

Bleeding at puncture site

Thrombus formation

Embolus formation –plaque dislodged from vessel wall by catheter,Dissection of vessel.

Puncture site infection (contaminated sterile field) , Contrast reaction.

ADVANTAGES & BENEFITS

Increased Effectiveness: Medical imaging technology gives radiologists high visibility throughout the procedure which increases the accuracy of the diagnosis and improves patient outcomes through targeted treatment.

Reduced Risks: Compared to conventional surgery, IR offers less blood loss and a lower risk for infection and other common complications that come with open surgery. Also, those who are at higher risk from anesthesia benefit as only local anesthesia and/or moderate sedation is used. Lastly, since the guidance is so precise, the likelihood of damage to surrounding healthy body parts is reduced.

Outpatient vs. Inpatient Stays: The IR procedures performed at UDMI are done on an outpatient basis. That means the patient is able to return home the same day treatment is received.

Lower Costs: Outpatient procedures are often significantly less costly than inpatient hospital stays. Additionally, your health insurance provider may cover a higher portion of outpatient procedures resulting in lower out-of-pocket costs for you.

Less Pain: IR procedures are performed through small incisions, so no stitches, staples, or large bandages are required. A local anesthesia is used so pain experienced during or after the procedure is moderate.

Quicker Recovery Time: Due to their minimally invasive nature, IR procedures require little recovery time. Generally, patients are able to return to daily life quicker than they otherwise would following traditional surgery.

The main benefits of interventional radiology techniques are that they can reach the deep structures of the body through a body orifice or tiny incision using small needles and wires.

That decreases risks, pain, and recovery compared to open procedures. Real-time visualization also allows precision guidance to the abnormality, making the procedure or diagnosis more accurate

These benefits are weighed against the additional risks of lack of immediate access to internal structures (should bleeding or a perforation occur), and the risks of radiation exposure such as cataracts and cancer.

DISADVANTAGES

The increased use of interventional radiological procedures brings with it an increased risk of cancer induction due to the possible high radiation levels used.

This risk must be balanced against any viable alternatives and should take into account the individual risks and benefits.

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