Abstract 200: A Newly Drug Delivery System Combined With the Resuscitative Endovascular Balloon Occlusion of the Aorta in a Pig With Hemorrhagic Shock Model

Abstract

Background: The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for hemorrhagic shock (HS) has grown in popularity. However, REBOA has a risk of complications related to blocking the blood flow downstream to the visceral organs. Several drugs have been reported so far to mitigate ischemia, including hydrogen gas (H 2 ); however, they could not reach the downstream of REBOA as they are distributed through the bloodstream. This study aimed to develop a system to deliver drugs to the ischemic organs where REBOA blocks the bloodstream. Methods: Herein, a female 40-kg swine volume-regulated HS model was used. In addition to the REBOA in zone 1, a catheter was inserted for drug delivery retrograde into the right femoral artery. The top tip of the catheter was positioned distal to the REBOA balloon. After HS induction (20% of the total blood volume), drug delivery capability was evaluated in three REBOA use patterns, such as controlled HS in normal time of full inflation , uncontrolled HS with liver injury in extended time of full inflation, and partial inflation. Simultaneously with the REBOA inflation, the intra-aortic irrigation of a drug-containing solution, H 2 -dissolved saline, was initiated. Results: The occlusion by the REBOA was achieved in all cases after shock induction (approximately 40 mmHg). In all patterns, the concentration of H 2 in the portal vein, which represents the concentration of outflow from the intestine and inflow to the liver, increased immediately after the irrigation. A full inflation setting required 30 mL/min of irrigation speed to obtain the minimum effective concentration of H 2 (1%), whereas a partial inflation setting required 2 mL/min. Conclusion: A drug delivery system combined with the REBOA was developed, which enabled the drugs to be administered downstream of REBOA. The newly developed system can potentially overcome the major limitations of REBOA.