Reporter’s Notebook: News From SIR 2019
Vol. 20 No. 5 P. 26
EDITOR’S NOTE: This article is based on press materials provided by the Society of Interventional Radiology at its recent Annual Scientific Meeting in Austin, Texas.
Training Model Improves Stroke Care Access, Maintains Quality
Training interventional radiologists to perform endovascular thrombectomies results in positive outcomes for patients experiencing stroke, according to a study presented at SIR 2019. Expanding access to this treatment provides patients timely access to this gold-standard treatment.
“With a limited availability of providers, thrombectomy is only available to 2% to 3% of eligible patients in the United States,” said Kelvin Hong, MD, FSIR, an associate professor and division chief of IR at Johns Hopkins University in Baltimore. “Patients don’t plan where and when they have a stroke. Our model of training board-certified interventional radiologists can expand access to quality, evidence-based care, and reduce the lifelong disability associated with stroke.”
Thrombectomy increases the survival rates among those suffering an acute ischemic stroke, reduces the likelihood of resulting disabilities, and speeds function recovery. However, to gain these benefits, thrombectomies must be initiated and performed quickly. Many hospitals do not have providers available to perform these treatments and must transfer patients to a facility where they can get this care, losing valuable time.
To determine an efficient and sustainable way to expand access to thrombectomy, the researchers developed an IR stroke team at Suburban Hospital, a community hospital in Montgomery County, Maryland. The team consisted of four interventional radiologists who were specially trained by a neurointerventional radiologist for six months. The entire team was available 24/7 with the neurointerventional radiologist helicoptered to the hospital for every case during this training period.
“We looked to change the dynamic in stroke care, where instead of transporting medically fragile patients, we brought in a specialist to perform this care and build the infrastructure necessary to provide this treatment to a community with limited stroke care resources,” said Ferdinand Hui, MD, a neurointerventional radiologist and associate professor of radiology and radiological science at Johns Hopkins University. “In a situation where every minute counts, we wanted to design our program to provide the training and organization necessary to bring 24/7 highly trained stroke interventionalists online as quickly as possible.”
Once the interventional radiologists were conducting the treatments independently, researchers measured the technical success of the thrombectomies performed by the newly trained physicians in 35 stroke cases using the Thrombolysis in Cerebral Infarction scale and found no significant differences compared with the 2016 HERMES meta-analysis of endovascular thrombectomy outcomes performed by other practitioners, such as neurointerventional radiologists and neurosurgeons. Additionally, 14% mortality in the first 90 days after the procedure was similar to 15.3% 90-day mortality among patients at stroke centers evaluated through the Journal of the American Medical Association–published HERMES trial. The median interval from symptom onset to the point when blood flow was restored was 325 minutes, compared with 285 minutes in previous research.
A limitation of the study may be in whether hospitals of varying sizes and resources can reproduce the program with the same outcomes. The research team plans to reevaluate the program after two years of data collection. They also plan to further evaluate the technical outcomes and time metrics in a second-year study with a goal of further reducing the time to treat each patient by improving efficiency and optimization year over year.
GEMS IR Scholarship Program Promotes Diversity
The Grants for Education of Medical Students (GEMS) program was announced at SIR 2019 by former SIR President Alan H. Matsumoto, MD, FSIR. Matsumoto, a professor in and chair of the department of radiology and medical imaging at the University of Virginia in Charlottesville, said the GEMS program is intended to attract medical students from diverse backgrounds to IR by providing scholarships to fund visiting clerkships/rotations in the specialty. Students who are seeking to be the first generation of physicians in their families and identify as being from racial or ethnic groups that are underrepresented in the medical field, female, or LGBTQ are eligible to apply for these scholarships, as are students who come from socioeconomically disadvantaged backgrounds.
“GEMS will allow medical students to gain an in-depth understanding of IR through a more personal experience in a new environment. As a prelude to the residency application and interview process, GEMS will enable selected third- and fourth-year medical students a chance to develop early mentoring relationships in IR and to broaden their professional networks,” Matsumoto said. “This program will facilitate connections between IR training programs and the next generation of [interventional radiologists] who might not otherwise have the opportunity to attend these clerkships.”
“SIR and SIR Foundation are incredibly grateful to Dr. Matsumoto, his family, and our inaugural industry sponsors—Boston Scientific, Penumbra, Siemens Healthineers, Gore, and Cook—for supporting this important initiative to engage diverse groups of medical students in interventional radiology,” said SIR President M. Victoria Marx, MD, FSIR, an interventional radiologist and professor of clinical radiology and diagnostic radiology residency program director at the Keck School of Medicine of the University of Southern California in Los Angeles. “Through this program, they are helping us achieve our vision to increase the diversity of IRs to better represent the patient populations we serve.”
For more information about GEMS, visit sirfoundation.org/gems.
Virtual Reality Enables Internal View of Patient Anatomy During Treatment
Immersive virtual reality (VR) may enable interventional radiologists to improve treatments using real-time 3D images from inside a patient’s blood vessels. Research presented at SIR 2019 shows that the interactive technology could provide faster, more efficient treatment with less radiation exposure and greater precision, ease, and confidence.
“Virtual reality will change how we look at a patient’s anatomy during an IR treatment,” said Wayne Monsky, MD, PhD, FSIR, a professor of radiology at the University of Washington in Seattle and lead author of the study. “This technology will allow physicians to travel inside a patient’s body instead of relying solely on 2D black-and-white images.”
The purpose of the study is to demonstrate the feasibility of using a VR headset to see and steer a catheter with electromagnetic sensors through the anatomy to certain blood vessels. Using a CT angiography scan, researchers created a 3D-printed model and a holographic image of blood vessels in a patient’s abdomen and pelvis. Monsky’s team of radiologists guided catheters through the 3D-printed model while a tracking system showed the image from the catheter through the VR headset. They compared the time taken to steer the catheter from the entry point of the femoral artery to three different targeted vessels with the time the process took using conventional fluoroscopic guidance, as well as time taken in similar real-life clinical angiographic procedures.
In 18 simulated procedures, researchers found the mean time to reach the three targeted vessels using VR was much lower than with fluoroscopy, the standard practice that uses an X-ray image. In the first vessel, VR took 17.6 seconds vs 70.3 seconds using the standard practice on the model and 171.2 seconds in the real-life procedure. With the improved efficiency, the researchers believe VR technology will create safer treatments by reducing the amount of radiation exposure to both patient and physician. They say it would also increase access to IR treatments.
“Currently, the life-saving potential of IR is limited to hospitals and areas with the resources to invest in image-guided technology,” Monsky said. “There are 3 billion people worldwide in rural areas who don’t have this access. This technology could allow for portability and accessibility so that these procedures are brought to rural areas using nothing more than a suitcase.”
Researchers also surveyed the practitioners who tried the technology, and they reported that VR improved the ease, precision, and efficiency of the treatment. Additionally, the users said they felt more confident in their abilities.
The VR software was developed through a University of Washington business incubator that supported development of a startup, Pyrus Medical, of which Monsky serves as CMO.
Smart Speakers Harnessed for Hospital Medical Treatments
Smart speakers that are customarily used in your living room can be programmed to act as an aid to physicians in hospital operating rooms, according to research presented at SIR 2019. Smart speakers, such as the Amazon Echo and Google Home, offer a conversational voice interface that allows IR physicians to ask questions and retrieve information needed for their patient treatments without breaking sterile scrub.
“During treatment, [interventional radiologists] rely on nuanced medical information delivered in a timely manner. When you’re in the middle of a procedure, you need to remain sterile, so you lose the ability to use a computer,” said Kevin Seals, MD, a fellow in IR at the University of California, San Francisco and lead author of the study. “This smart speaker technology helps us to quickly and intelligently make decisions relevant to a patient’s specific needs.”
The researchers developed a device-sizing application for the Google Home smart speaker. The application processes questions from a human voice and provides recommendations on the precise sizing of medical devices. For example, if an interventional radiologist needs to know what size sheath to use to implant a stent in a patient’s blood vessel, the smart speaker can quickly and accurately communicate the correct size based on the specific circumstances, which helps the physician in making a final decision.
“There are hundreds of devices—with more being introduced every day—making it difficult to determine the correct sizing or materials needed in every circumstance,” Seals said. “This technology allows physicians to concentrate more closely on the care of their patients, devoting less time and mental energy to device technicalities.”
In developing the application, size specifications were acquired using literature reviews for 475 IR devices, such as catheters, sheaths, stents, vascular plugs, and others. Natural language processing was implemented using Dialogflow, which extracted the information of interest from an input query. Logic operations and other data processing were performed using a Python script deployed to the cloud.
The researchers plan to continue to build on this technology and expand its scope to include information on material costs and inventory databases. Having this information readily available will make treatments more efficient, cost-effective, and beneficial to patients. Further research will look to yield information for physicians in other specialties and provide information from EHRs and patient clinical data, such as allergies or prior surgeries.
‘Tennis Elbow’ Treatment Reduces Pain, Inflammation Without Surgery
Tennis elbow, a painful chronic condition that affects up to 3% of the US adult population, can be effectively treated through transcatheter arterial embolization (TAE), an image-guided, nonsurgical treatment that decreases abnormal blood flow to the injured area to reduce inflammation and pain, according to research presented at SIR 2019. The condition, also known as lateral epicondylitis, stems from repetitive stress injuries that occur in activities such as sports, typing, and knitting, and the injury is common in carpenters, cooks, and assembly line workers, impacting basic tasks that affect job performance and quality of life. While pain is a hallmark symptom, chronic tennis elbow can cause loss of grip and arm strength, limited use of the arm, and burning sensations on the outer portion of the arm.
“Tennis elbow can be difficult to treat, leaving many patients unable to perform the simplest tasks, such as picking up their children, cooking dinner, or even working on a computer. With this frustration, many patients turn to invasive major surgery after years of failed physical therapy and medication use,” said Yuji Okuno, MD, PhD, founder of the Okuno Clinic in Japan and lead author of the study. “We were interested to see if this technique, already in use in other areas of the body, would be effective for this common debilitating condition and help people immediately regain a range of motion that many of us take for granted in our everyday tasks.”
Okuno’s team conducted a prospective study in 52 patients with tennis elbow who did not find relief from other forms of treatment. The patients received TAE between March 2013 and October 2017 and were followed for up to four years after the treatment. The researchers found statistically significant reductions in pain rating scores, using methods including the Quick Disability of the Arm, Shoulder, and Hand scores; visual analog scale pain rating scores; Patient-rated Tennis Elbow Evaluation scores; and pain-free grip strength. Additionally, images taken in 32 patients two years after undergoing TAE showed an improvement in tendinosis and tear scores.
The treatment can be completed in approximately one hour and requires only a needle hole to access the radial artery in the wrist under local anesthesia. A catheter is moved through the wrist to the elbow where the inflamed blood vessels are embolized, preventing excessive blood flow to the affected part of the elbow. The treatment is safe and effective and doesn’t require physical therapy, according to the researchers. No adverse events were observed, and no patients experienced negative effects to the surrounding bones, cartilage, or muscles.