From Finding Problems to Saving Lives: The Evolution of Interventional Radiology

Interventional radiology (IR) is on the front lines of innovation in healthcare. The story of its evolution from a diagnostic imaging specialty to a therapeutic powerhouse is a stand-out example of the great things that can happen when innovative physicians look at problems in new ways.

What is interventional radiology?

IR is a medical specialty that delivers minimally invasive diagnostic and therapeutic treatments throughout the body using real-time radiological imaging guidance to see inside the body.

Imaging technologies used in IR can include:

  • X-ray fluoroscopy
  • Computed tomography (CT)
  • Ultrasound
  • Magnetic resonance imaging (MRI)

Broadly, interventional radiologists perform procedures in every part of the body except two: the heart and the brain. Those two areas are covered by other IR-related specialties that use minimally invasive techniques, including interventional cardiology (heart) and neuro-interventional radiology (brain). However, IR’s area of specialization is continuing to expand: in 2019, the Society of Interventional Radiology encouraged stroke treatment training for IR physicians, to take advantage of their expertise and save lives for more stroke sufferers.[1]

The importance of minimally invasive treatments

“Minimally invasive” is one of healthcare’s favorite buzz phrases. Although the term can reasonably be applied to any technique that avoids cutting into the patient’s body, thus minimizing the treatment’s traumatic impact, “minimally invasive” is what IR physicians do every day.

One example of a minimally invasive technique is the endovascular approach. Endovascular techniques use thin tubes, called catheters, threaded through the blood vessels to reach the area to be treated. The physician accesses the blood vessels through a pin-sized puncture in one of the body’s arteries or veins, typically at the groin. The physician uses real-time, high-definition X-ray fluoroscopy or other imaging technologies to track the catheter’s progress and perform any number of interventions.

Minimally invasive techniques have been associated with positive patient outcomes, including:

  • Lower risk of complications, including bleeding
  • Less scarring
  • Shorter hospital stays (many are outpatient procedures)
  • Less pain
  • Faster recovery
  • Less impact on the patient’s immune system
  • Lower cost

[sidebar] What Does IR Do?

Here are a few examples of the many diagnostic and therapeutic procedures performed by IR physicians:

  • Aneurysm coiling
  • Angiography
  • Biopsies
  • Chemoembolization
  • Cryoablation
  • Drains
  • Embolization
  • Feeding tubes
  • Fistula declot
  • Hemodialysis access
  • IVC (inferior vena cava) filter placement
  • Lumbar punctures
  • Myelograms
  • Prostatic artery embolization
  • Radiofrequency ablation of tumors
  • Stent placement
  • Thrombolysis treatments
  • Uterine fibroid embolization
  • Vascular and venous stenting, angioplasty, and venoplasty
  • Vertebroplasty, Kyphoplasty

The genesis of IR treatments

Charles Dotter, MD is widely considered the father of IR. A prodigiously talented physician with an eccentric personality and determined manner, Dr. Dotter became the youngest ever chair of a radiology department at only 32 years old. In the 1960s, radiologists used minimally invasive, catheter-based procedures solely as a diagnostic tool. They used catheters and imaging to identify the source of a problem.

In June 1963, Dr. Dotter delivered a speech at the Czechoslovak Radiological Congress (CRC) in which he described his vision of catheter-based, minimally invasive treatments. “The angiographic catheter can be more than a tool for passive means of diagnostic observation; used with imagination, it can become an important surgical instrument.”[2]

Six months after that presentation, in January 1964, Dr. Dotter was asked to identify the site of a blockage in a vein. The 82-year-old patient had no blood flow to her lower leg, and part of her foot had become gangrenous. Her surgeon planned to amputate, and Dr. Dotter was asked to identify where in her leg the blockage was, so that the surgeon would know how much of the leg needed to be amputated. The patient, however, did not want her leg amputated.

Using femoral angiography, Dr. Dotter threaded a catheter into the patient’s leg and saw the blockage on the X-rays. Despite the notation on the order – underlined, and in capital letters –  from the surgeon to “visualize, but do not try to fix!!!” the blockage, Dr. Dotter had found the perfect test case. He expanded the clogged artery from the inside.

The patient was able to avoid amputation. She walked out of the hospital and remained mobile until her death more than two years later.

As news of Dr. Dotter’s successful procedure – the first angioplasty – spread, IR took off and began to spawn more innovations. In the following years, IR specialists pioneered amazing technologies for minimally invasive treatments all over the body. Examples include:

Embolization

Embolization refers to blocking the flow of blood to an area of the body, using medicine or physical materials. It began as a way to stop people from bleeding to death, but it has evolved into a powerful treatment modality. Embolization has immense therapeutic potential, from emergency management of trauma patients to treating cancer and dozens of other conditions as well.

Embolization can be used to:

  • Stop bleeding
  • Cut off blood flow to a tumor, “starving” it
  • Deliver radioactive agents to a specific tumor site
  • Zap connections between specific arteries and veins to address malformation
  • Treat aneurysms

Balloon angioplasty

A procedure that expands clogged or blocked blood vessels using a thin, balloon-tipped catheter threaded into the vessel and expanded. This lifesaving technique is a cornerstone of peripheral artery disease (PAD) treatment and works anywhere in the vascular system.

Emerging cancer treatments

One of the reasons cancerous tumors grow so rapidly is that they hijack the body’s blood vessels and use them to feed the tumor. IR techniques can shrink and destroy tumors in a number of ways:

  • Chemoembolization – delivering chemotherapy medication directly to the tumor while also cutting off the blood flow
  • Radioembolization – delivering radioactive material to the tumor while also blocking the tumor’s blood flow to shrink or treat the tumor, without damaging the healthy tissue nearby
  • Cryoablation – applying cold to destroy tumor cells
  • Radiofrequency – applying radiofrequency energy (heat) to destroy tumor cells

Spinal fracture treatments

Vertebral compression fractures are excruciating and damaging to a person’s mobility. Kyphoplasty and vertebroplasty treat compression fractures without incisions, shoring up the fractured vertebra and typically enabling the patient to walk out of the hospital the same day.

Cutting-edge innovations for bone cysts

A great example of IR innovation occurred when an IR physician developed a new way to treat a child who had a recurring cyst growing in her arm bone, weakening it significantly and causing multiple fractures. The IR physician used a minimally invasive approach to burn the cyst wall and attach a bone graft – all through two pin-sized incisions. The radiofrequency energy killed the cyst wall cells, preventing regrowth, while the bone graft allowed new, healthy bone to form at the site. One year after the procedure, the patient is back to full strength and activity.[3]

Conclusion

IR’s spectacular birth and rapid rise is a lesson in the potential of creative new approaches to medical and surgical interventions. There is no telling what procedures IR will develop in the future, but one thing is clear: minimally invasive options are good for patients.

[1] Society for Interventional Radiology. Sir Strategic Initiative Plan: IR Involvement in Endovascular Stroke Care. March 7, 2019. https://www.sirweb.org/contentassets/b953d2208b9f43ffaac237488f09bb10/update_stroke_advisory_3_7_19.pdf

[2] Hillman, Bruce and Jeff Goldsmith. The Sorcerer’s Apprentice: How Medical Imaging Is Changing Health Care. Oxford: Oxford UP, 2010.

[3] Lurie Children’s Hospital Blog. “Interventional Radiology Cutting-Edge Procedure Puts Brooklyn Back in the Game.” (October 2019) https://www.luriechildrens.org/en/blog/interventional-radiology-cutting-edge-procedure-puts-brooklyn-back-in-the-game/ Accessed October 30, 2019.