Above: Jennifer Gould, MD, focuses on the monitor as MIR resident Wei Wang, MD, helps her perform a procedure.
The journey of interventional radiology is defined not by destinations but by the paths traveled. Procedures that once required surgery, sutures, scars, hospitalizations and lengthy recoveries can be completed via a brief trip to an IR suite, followed by a bandage and good night’s sleep at home.
“We cross many organ systems and disease states. The underlying theme is that we do minimally invasive, image-guided procedures,” says Michael D. Darcy, MD, professor of radiology and chief of interventional radiology at Mallinckrodt Institute of Radiology (MIR), “The vast majority are done through a tiny skin nick that doesn’t need a stitch.”
Interventional radiology, or IR, was recognized as its own primary specialty in 2012 by the American Board of Medical Specialties. IR procedures have replaced surgical options in addressing many injuries and diseases. Its scarcely invasive approaches have been proven to reduce recovery time, hospital stays and risks.
Many interventional radiology procedures formerly handled in operating rooms have become commonplace in the IR suite. Implanting permanent vascular access, treating hepatic and renal cancers, and opening vessels with implantable stents, to name a few. In addition, “a transplant program or a Level 1 trauma center can’t be accredited without interventional radiology,” says Darcy. “There are procedures that simply can’t be done with standard surgical techniques.”
MIR’s interventional radiology service, which was established in 1987 at Washington University School of Medicine, is one of the 12 largest in the U.S. Few major IR centers are located in the Midwest. “The closest comparable center – that provides the full range of services and handles the complicated cases that we do –would be in Chicago,” Darcy says.
Charles Dotter, MD, a radiologist at Oregon Health & Science University, is credited with the genesis of interventional radiology in the 1960s. His first patient, not considered a surgical candidate, was at risk of losing her foot due to an arterial blockage. Dotter passed catheters across the narrowing, re-established blood flow and the foot healed. And thus began the IR revolution.
Dotter’s groundbreaking procedure was followed by a rapid rise of IR techniques. Radiologists have expanded the range and scope of interventions in step with advances in imaging and devices. Key to IR’s evolution is innovation resulting from radiologists’ collaboration with device manufacturers.
“We would think of an idea and the catheter companies would build it,” Darcy says. “Or they would come to us with a new device and we would say, ‘What can we use it for?’” Innovation grew with new needs.
Large catheters used for the embolization of colonic bleeding 35 years ago have been replaced. “The tools they used blocked off fairly large vessels and there was a very high infarction rate,” Darcy says. “Now we have a slew of micro-embolic devices that allow us to go to the wall of the bowel and block a very selective blood vessel.”
As interventional radiology grew, so did its applications.
“With the technology that we possess in IR, there is no vessel in the body that we cannot reach, whether it is in the brain or in the feet,” says Raja Ramaswamy, MD, assistant professor of radiology and surgery. “What brought me to interventional radiology was working with virtually all organ systems and a wide scope of diagnoses and disease processes. It is a very innovative field.”
Above: Michael D. Darcy, MD, professor of radiology and chief of interventional radiology at MIR.
“Something new is always coming,” adds Jennifer Gould, MD, associate professor of radiology. “The complexity of much of what we do is increasing. Now when I insert a catheter, chances are I am going to do more than a diagnosis. I am going to do a minimally invasive procedure that could make a profound difference for a patient. They could go home that day or the next.”
Darcy has devoted much of his research to transjugular intrahepatic portosystemic shunts (TIPS) to address portal hypertension, where a stent is placed in the cirrhotic liver from the portal vein to a hepatic vein.
The procedure lasts about an hour and the patient goes home the next day. TIPS basically has replaced the surgical procedure, says Darcy. “In the era of surgical portacaval shunts there was a major incision, multiple days if not weeks in the hospital, usually weeks of recovery and mortality was much higher.”
Approaching lesions with catheters rather than scalpels spares healthy tissue and may help patients avoid surgery. Uterine fibroid patients, for example, may be eligible for an IR procedure rather than a hysterectomy.
“We combine the techniques of catheterization and injection to block arterial supply to the fibroids,” Darcy says. “That shrinks the fibroids and in many cases takes care of the problems without surgery.”
Ramaswamy expects interventional radiologists increasingly will deploy embolization to treat prostate disease. More than half of men over the age of 60 have enlarged prostates and about 3 million men in the U.S. are diagnosed with prostate cancer annually. “IR can offer a minimally-invasive treatment approach by going into the vascular supply and delivering medications that help to decrease the size of the prostate,” he says.
IR also is an adjunct to surgery when postoperative complications arise. In the past, if a patient developed bleeding or post-operative abscess they would go to surgery and have a large incision made, Ramaswamy says. “Now in IR we make an incision the size of a pin, go directly to the site, and stop the bleeding or drain the infection.”
The ability to deliver chemotherapy, embolization and ablation through the narrowest pathways presents interventional radiology with opportunities for prominence in oncology treatment.
“Chemo doesn’t work very well by itself for some liver cancers and many patients present beyond the point of surgical resection,” Darcy says. “We can insert a probe percutaneously under CT guidance and ablate the tumor with heat or cold. We can prolong life and sometimes achieve cures. For some small tumors the results are close to what can be accomplished surgically.”
IR delivery will assure the precise placement of coming chemotherapies, Ramaswamy says. “The future of oncology is more targeted drug therapies including nanoparticles to treat tumors. If we know the exact biology of the tumor we can make a personalized drug that specifically targets the tumor.”
The Clinic Experience
Early on, IR founder Dotter advocated for interventional radiologists to assume greater patient management responsibilities. It didn’t make sense, he argued, for radiologists to return patients to practitioners unfamiliar with IR procedures.
“We are very aggressive about following our patients,” Darcy says. “We had a formal clinic here 30 years ago, long before many IR groups did.”
The ability to treat various organ systems is what attracted Raja Ramaswamy, MD, to interventional radiology.
The clinic provides a much better way of assessing patients and gives the interventional radiologists time to discuss the procedure and its ramifications with the patient. “It also makes things much easier for the referring doctors because we take care of precertifications and arrange admissions,” says Darcy.
“The clinic experience is something I love about the field,” says Sarah Connolly, MD, who joined the interventional radiology section in July after completing an IR fellowship at MIR. “It plays an important role in allowing us to establish the physician-patient relationship and provides an opportunity for teaching.”
The Accreditation Council for Graduate Medical Education approved dedicated integrated interventional radiology residencies in 2014. Mallinckrodt Institute of Radiology organized one of the first programs and matched its first two residents in 2016.
“It’s a five-year program, following one year of internship, that compresses diagnostic radiology down to three years and a couple of months and leaves the remaining time, almost two years, for interventional radiology training,” says Gould, who also is MIR’s diagnostic radiology residency program director. “The traditional way to become an interventional radiologist had been to do a four-year diagnostic radiology residency followed by a one-year IR fellowship.”
Connolly looks forward to the continued development of IR education at Mallinckrodt. “The passion and innovation historically applied to developing new tools and procedures in IR also needs to be applied to the training of IR residents,” she says. “The broad case mix in IR and the benefits of deliberate practice suggest a role for incorporating standardized and graduated simulation into IR residency training and I look forward to being a part of this moving forward.”