In this episode, host Dr. Michael Barraza interviews Dr. Rehan Quadri, interventional radiologist, about the definition, indications and techniques for treating clot in transit.
We begin by defining and describing when to treat clot in transit. Traditionally, the definition is the washing machine mobile clot in the right atrium (RA) or right ventricle (RV). In these situations, the next place for the clot to travel is the pulmonary artery (PA). Mortality in these cases can reach as high as 30%, which is why these cases are considered emergencies. There is another category of clot in transit where a clot is partially adhered to a vessel wall, catheter, or heart valve. They are most commonly diagnosed via an echocardiogram, or found incidentally on a CT angiogram. They commonly present as catheter malfunction with symptoms resembling SVC syndrome.
Dr. Quadri explains his usual method for retrieving clot in transit, though he notes each case is complex and different depending on the etiology and the overall status of the patient. In general, unless there is a massive PE, he treats the clot in transit before the PE. He always ensures with the preoperative echocardiogram that there is no interatrial shunt or patent foramen ovale (PFO). At the beginning of the case he checks PA and RA pressures.
He uses a 24 French Inari Flowtriever with FLEX technology, which helps with tough angles. He uses ICE guidance in all clot in transit cases. To help with orientation when using the ICE catheter, he recommends pointing it anteriorly while entering the RA, then using the Eustachian ridge, an echogenic line in the RA, to confirm you are in the RA and indicating that you should see the tricuspid valve as you advance. He uses the FlowSaver device, and always has 2 units of blood in the room just in case. At the end of the case, he remeasures the PA pressures, then injects through the Inari sheath to verify that there is no residual before finally doing a pulmonary arteriogram. He sends all the clots to pathology, and has seen that the morphology is usually mixed, with some organized fibrin in addition to acute thrombus.