Spring break: Interventional neuroradiology clinical interlude

At the end of last semester, my classmates and I were required to complete a clinical interlude. I spent mine in the emergency room then followed a cardiothoracic case (aortic dissection) upstairs to the operating room. I enjoyed the clinical interlude so much that I decided to spend a couple days out of my Spring break doing something similar.

I wanted to get exposure to neurosurgery/neurology/radiology and so arranged to shadow a neurosurgeon who practices interventional neuroradiology. It was really a perfect fit.

Interventional neuroradiology: Procedures

My clinical interlude started with an embolization procedure to fix an arteriovenous malformation, which is basically just a tangle of blood vessels in the brain that predisposes the patient to a constellation of complications (e.g. intracranial hemorrhage). The whole point of the embolization procedure is to selectively block off blood flow to the region of malformation to make surgical resection of the malformation easier. It's common for patients to have many embolization procedures before surgical resection, each time blocking off a few more blood vessels feeding the malformation. Yesterday was this patient's fourth embolism procedure.

It's extraordinary, when you think about it, that such a procedure is even possible. A catheter is inserted in the femoral artery in the groin area. From there, a wire is fed up through the abdominal and thoracic aorta, through the aortic arch, and into the brain via the carotid or vertebral arteries. What's even more amazing is what happens once the wire is inside the blood vessels of the brain, which get smaller and smaller as they continue to branch off.

Doctor S. navigated the maze of tortuous arteries simply by twisting the wire in his hands so the tip of the wire would point one direction or another. Meanwhile, he tracked his progress in real time using fluoroscopy. In this way, he was able to make his way to the arteriovenous malformation in the frontal lobe. Once there, a thick liquid substance called onyx was slowly injected into the artery to occlude it. The onyx moves through the artery like lava and interacts with components in the blood to harden and form a permanent plug. The onyx injection is also tracked in real time: it appears on the screen as a black blob that gradually fills the vessels surrounding the malformation. One of the primary concerns in tracking the onyx injection is to make sure that it doesn't enter the venous outflow, because then blood flowing into the malformation from other arteries would have fewer routes of escape and pressure would build up.

Fluoroscopy imaging involves radiation, which means that everyone in the operating room must wear protective lead shielding, including a lead neacklace to protect the thyroid. After so many hours, that lead sure did feel heavy! Also, I was excited that I got to scrub in. There's a particular way to put on the surgical gown and gloves in a sterile manner that has a way of exposing a novice. Being a first-year medical student, I have license to own up to my inexperience, and the nurses were great at showing me the ropes. During a diagnostic angiogram today, the nurse also took the time to explain to me how all the different types of catheters and wires work, which I greatly appreciated.

Academic day: Conferences

Tuesdays are academic days, so today after rounds in the neuro intensive care unit (NICU), I attended two conferences. The first was a neuro-oncology conference during which neurosurgeons, oncologists, radiologists, and pathologists all meet to discuss cases. This was a nice course correlate, considering I was recently studying pathology for Disease and Defense.

The second was a "Morbidity and Mortality" conference during which neurosurgeons presented recent cases that had complications. The real purpose of this conference, it seems, is to identify mistakes to learn from them and prevent them from happening again. Although the majority of complications were straightforward, a few cases prompted some animated debate. It was fascinating to watch this group of neurosurgeons think through a case together and argue their differing opinions (all in a collegial atmosphere, of course). There was also one patient who had intracranial bleeding that a resident explained by acknowledging that he had made a mistake. Mistakes happen; they are a reality of training. Still, I was somewhat surprised to hear it discussed so matter-of-factly. The resident obviously did not appear too pleased with himself, but the attending neurosurgeons talked through the case in an academic manner that highlighted the factors that led to the mistake. I'm glad that I was able to get a glimpse into this aspect of training.

Overall impressions

Even though it meant a shorter vacation back home, I'm very glad that I decided to set aside these two days of my Spring break for an unofficial clinical interlude: a welcome refresher of why I'm in medical school. I got my exposure to neurosurgery/neurology/radiology, I learned a lot about embolization and angiograms specifically, and I also networked with many doctors and residents who invited me to come back when I get the chance.

Now, it's time for a real vacation.