Doppler Sonographic Findings in an Experimental Rabbit Model of Necrotizing Enterocolitis

Objective. The purpose of this study was to examine the clinical applicability of Doppler sonography by evaluating Doppler sonographic findings in an experimental rabbit model of necrotizing enterocolitis (NEC). Methods. Necrotizing enterocolitis was experimentally induced using a combination of endotoxin, hypoxia, and cold stress in 23 rabbits. Doppler sonography was performed to obtain the Doppler spectrum of the superior mesenteric artery. From the flow profile, the peak systolic velocity (PSV) and resistive index (RI) were calculated at 5 time sessions: initial and 1 to 2, 3 to 4, 5 to 6, and 20 to 24 hours. Animals were divided into 2 groups based on pathologic NEC scores (NEC-positive [NEC+] group versus NEC-negative [NEC-] group). Differences between the groups with regard to RI and PSV values were evaluated for each time session. Results. Comparison of RI and PSV values between the NEC+ and NEC- groups revealed a significant increase in the PSV in the NEC+ group during the 1- to 2-hour session (P= .0199). Comparison of RI and PSV differences revealed a significant increase in RI and PSV differences in the NEC+ group during the 1- to 2-hour session (P = .0095 and .0013, respectively). In the other time sessions, there was no difference between the groups. Conclusions. The NEC+ group showed a significant increase in the PSV and RI during the 1- to 2-hour period.