Intravascular Ultrasound Guidance in Percutaneous Mechanical Thrombectomy: A Single-Center Experience From the FLASH Registry.

BACKGROUND

Traditionally, iodinated contrast is utilized during catheter-based mechanical thrombectomy for pulmonary embolism (PE). Recently, there have been disruptive contrast shortages. Furthermore, contrast can cause contrast-induced acute kidney injury especially in patients with pre-existing chronic kidney disease, necessitating an alternative imaging method. We present utilization and feasibility of an intravascular ultrasound (IVUS)-guided strategy for mechanical thrombectomy in PE from the FLASH registry.

METHODS

In this FLASH patient subset, IVUS was used to image the pulmonary arteries (PAs) before and after mechanical thrombectomy with the FlowTriever System at one study site comprising three hospitals. The Philips Visions PV 0.035" IVUS catheter was used for all the IVUS-guided cases in a standardized manner.

RESULTS

Between July 2019 and December 2021, 26 FLASH patients enrolled at this site underwent IVUS-guided thrombectomy. Most patients (96.2 %) had intermediate-risk PE and 3.8 % had high-risk PE. The mean baseline composite RV/LV ratio was 1.36 ± 0.27 and the mean simplified Pulmonary Embolism Severity Index (sPESI) score was 1.9 ± 1.2. A decreasing trend in contrast agent volume usage was observed over time and several later procedures were performed with IVUS guidance alone. Mean PA pressure significantly decreased immediately following thrombectomy from 34.8 ± 8.3 to 25.5 ± 7.3 mmHg (p < 0.0001). Systolic PA pressure also significantly decreased immediately from 55.4 ± 13.9 to 39.5 ± 12.5 mmHg (p < 0.0001). Significant improvements were seen in echocardiographic assessments of RV function at a mean 87-day follow-up compared with baseline.

CONCLUSIONS

In conclusion, the use of IVUS guidance with minimal or no angiographic contrast during mechanical thrombectomy for acute PE is technically feasible.