To explore the ultrasonic appearance and the relevant mechanism of combined treatments of dexamethasone, verapamil and continuous low flow reperfusion in protecting the unilateral testicular incomplete torsion ischemia-reperfusion injury in a rabbit model.

Thirty healthy adult male rabbits were randomly divided into control group, dexamethasone group (group DS), verapamil group (group VP), continuous 30 seconds low flow reperfusion group (group H) and combined treatment group (group L). Each group had 6 rabbits. The unilateral testicular incomplete ischemia model was made under the ultrasonic monitoring. The control group was reperfused immediately, while the other groups were given dexamethasone, verapamil, continuous 30 seconds low flow reperfusion and the combined treatment, respectively. They were reperfused completely after 10 minutes. Before reperfusion and 3 days later, the contrast-enhanced ultrasound was made respectively, and the peak intensity (PI), time to peak (TTP), mean transmit time (MTT) and area under curve (AUC) were analyzed. The levels of malonaldehyde (MDA), superoxide dismutase (SOD), xanthine oxidase (XOD) and hypoxia inducible factor-1α (HIF-1α) were tested after the operated testicular tissue removed 3 days later.

Before the reperfusion, ultrasonic parameters showed no statistical significance between groups (F_PI=0.85, F_TTP=1.31, F_MTT=1.84, F_AUC=0.60, all P>0.05); and time-peak curve had the same ?slow in and slow out? form. Three days after the reperfusion, the control group′s time-peak curve appeared ?fast in slow out?, while the L group′s was ?same in same out?. In each treatment group, the MDA was lower, SOD was higher, XOD was lower, HIF-1α was higher than control group. They were statistically significant (F_MDA=13.62, F_SOD=61.16, F_XOD=9.23, F_HIF-1α=57.64, all P<0.01). Compared with group H, group L′s SOD was higher and XOD was lower (t=2.938, 4.263, both P<0.01). Group L′s XOD was lower and HIF-1α was higher than group DS (t=2.64, P<0.05; t=6.47, P<0.01). Compared with group VP, Group L′s HIF-1α was higher, and they were statistically significant (t=3.45, P<0.01).

Contrast microbubble ultrasound can observe tissue microcirculation changes of testicular torsion/detorsion in real time. The dexamethasone, verapamil and continuous low flow reperfusion were different in the therapeutic effect of ischemia-reperfusion injury after testicular incomplete torsion/detorsion, and the combined treatment obtained a better curative effect.