Interventional Radiology (IR) is a medical specialty of Radiology utilizing minimally invasive image guided procedures to diagnose and treat diseases in nearly every organ system. The Interventional Radiologists are the Radiologists with an additional specialized training to perform the procedure.
Most IR procedures are minimally invasive alternatives to open and Laparoscopic (key hole) surgery and the procedures start with passing a needle through the skin and advancing a catheter under imaging guidance, most commonly Fluoroscopy but also ultrasound (USG) and Computed Tomography (CT) to the target. Hence the procedure is also known as Pin Hole Surgery. The procedures are performed under local anesthesia with reduced Hospital stay. The recovery is faster and patient is mobilized in short period of time.
Two main categories of diseases included in the IR procedures:-
Vascular IR: Organs or diseases treated via the blood vessel supplying the organ
To increase the blood flow : Angioplasty & Stenting
Thrombolysis + Thromboaspiration
To decrease the blood flow : Embolisation
Filter placement
Non-vascular : Diseases treated by directly puncturing the organ or diseased tissue
Why Do Blood Vessel Get Blocked?
Blood vessel is like a pipe and gets blocked because of causes :
Within the Lumen : Blood Clot
Dislodge Plaque Material
Foreign Material
Diseases of the Wall : Atherosclerosis
Fibromuscular Dysplasia
Aorto-Arteritis, etc.
Compression from Outside: Mass from Outside Pressing the Blood Vessel
External Application or Dressing Material
Blood vessels transport blood, O2 and nutrients, etc. to the organ. If vessel is blocked, the supply to the organ reduces or ceases; it leads to dysfunction of the organ or tissue.
What is Angioplasty and Stenting?
Cholesterol, triglycerides etc. are fatty substances, which get deposited on the inner lining of the blood vessel, resulting in reduced luminal diameter of the blood vessel.
In the catheter lab, Interventional Radiologist guides a wire and balloon catheter/ stent upto the site of narrowed blood vessel. The balloon is inflated and stent is deployed to widen the lumen and keeps the segment wide and improved blood flow to the organ. This helps improve the function of the organ.
What is Thrombus and How does IR Helps Treat Thrombosis of a Blood Vessel?
Thrombus is blood clot within the blood vessel. It can form at a site or may get dislodged from anywhere upstream in the vascular system.
The clot blocks the flow in the blood vessel and often leads to acute, severe dysfunction of the organ or tissue. This needs urgent treatment. IR helps improve or dissolve the blood clot by aspiration or lysis of the clot.
IR directs the catheter upto the site of the clot and applies suction to aspirate or inject clot-dissolving material to lyse the clot.
In certain diseases, there is excessive blood flow to the organ or tissue. This may lead to:
Bleeding
Growth of tumor
Organ or tissue dysfunction
Pain, swelling or redness, etc.
IR can guide a catheter upto the site of bleeding, tumor or painful pathology site and block the excessive blood flow. This is done by either injecting particles, liquid thrombus forming material or devices to plug the blood vessel.
Common conditions where embolisation helps are:
Bleeding anywhere
Before certain surgical procedures / pre op angioembolization
Tumor treatment: Liver, Kidney, Uterus, etc.
What are the Non-Vascular IR Procedures?
Solid tumors, fluid filled collections, painful sites etc. can be treated by IR procedures. Under USG/CT or X-ray guidance, IR can target the disease site and introduce a needle, probe or inject medication to treat the disease. These procedures are:
Biopsy: Remove tissue for histopathological diagnosis
Drainage: Pus, bile, urine, etc.
Ablation: Soft tissue masses and tumors in liver, kidney, lung, etc.
Pain management: Backache, bony pain, abdomen, chest, etc.
Recannalisation: Fallopian tubes, biliary + urinary stenting.
How safe are IR Procedures?
In any disease conditions, as compared to corresponding surgical option of treatment, IR procedures are considered to be safer and better tolerated by patients. Patients prefer this option because:
There are no cuts, sutures or major dissection
Limited anaesthesia
More directed treatment, hence non-target tissue is not affected
Can be undertaken in patients with other co-morbid medical conditions, like heart, lung, and kidney disease.
Hospitalization stay is reduced
Minimal supportive care and early mobilization
What are the Drawbacks of an IR Procedure?
Being often conducted under minimal anesthesia, it can occasionally be painful and need pain management.
Unpredictable complications require close monitoring in the ICU/ward.
Infection control is mandatory
Follow up to assess the outcome is necessary
Recurrence of disease may need repeat intervention or surgery
What should a Patient enquire Before an IR Procedure?
Patient or family members should understand the disease process and urgency for a procedure.
To enquire about success, failure, risks/ complications and limitations of IR.
Discuss other treatment options.
Skill, experience of IR and availability of infrastructures in the institution
Cost comparison with other modalities of treatment.
Cost/ benefits of a procedure and options.
Follow up protocol and additional medical treatment.
Why is the awareness about IR less?
There are few trained and practicing IR in the country.
Very few Institutions have training program in IR.
Awareness in the subject amongst public, general physicians and even certain consultants is limited
Most of the patients are not given an option of the IR procedure
Availability of facilities in majority of institution is limited
Availability of IR material is limited and often expensive
Most of the patients are not given an option of the IR procedure
For a patient it is important to be:
Aware of this minimally invasive procedure and understands its advantages
Google search about the disease treatment options
IR Procedures
• Percutaneous transhepatic biliary drainage (PTBD)
• Ophthalmic artery chemoinfusion
• Angioplasty / Stenting
• Balloon dilatation of strictures
• IVC filter placement
• Thrombolysis of ischemic bowel
• Radiofrequency ablation
• Microwave ablation
• Electroporation
• Liver Tumours
o Transarterial embolization (TAE)
o Transarterial chemoembolization (TACE)
o Transarterial radioembolization (TARE)
• Coiling of Aneurysms
• Angioembolization for GI Bleeding
• Pre op angioembolization of tumors
• Uterine artery embolization
• Vertebroplasty
• Central line access
• Sclerotherapy
• Biopsies
• Transjuglar intrahepatic portosystemic shunt (TIPS)
• Balloon Occluded Retrograde Transvenous Obliteration of vairices (BRTO)
• Percutaneous nephrostomy (PCN)
• DJ stenting
Dr. Imran Nazir Salroo is Interventional Radiologist, Tata Memorial Hospital, Mumbai