Abstract Intestinal ischemia–reperfusion (I/R) injury is a major complication of aortic occlusion during resuscitative thoracotomy or resuscitative endovascular balloon occlusion of the aorta (REBOA). We investigated whether targeted intra-arterial delivery of hemoglobin vesicles (HbV) attenuates intestinal I/R injury in a rat thoracic aortic cross-clamping model. Male Wistar rats underwent 60 minutes of thoracic aortic occlusion followed by 60 minutes of reperfusion. Animals received intra-arterial HbV (1.25 mL/kg every 10 minutes; n=5) or saline (n = 5) via the femoral artery; sham animals (n = 3) underwent instrumentation only. Compared with saline controls, HbV-treated rats demonstrated higher postreperfusion systolic blood pressure (56 ± 4 vs 34 ± 8 mmHg; P=.002) and lower plasma lactate levels (2.7 ± 0.4 vs 7.5 ± 0.4 mmol/L; P < .001). Intestinal injury was significantly attenuated in the HbV group, with lower Chiu scores (median 2.0 vs 4.0; P=.018), reduced TUNEL-positive area fraction (P = .003), and decreased inducible nitric oxide synthase–positive area fraction (P = .006). Targeted intra-arterial HbV administration significantly reduced early intestinal I/R injury in this exploratory proof-of-concept model and may represent a promising adjunctive oxygen-carrying strategy to protect distal organs during prolonged aortic occlusion.
Tsuruta et al. (Sun,) studied this question.