Effect of intra-abdominal volume increment on kidneys in minipigs with intra-abdominal hypertension after hemorrhagic shock and resuscitation

Abstract

Background: To investigate the effect of intra-abdominal volume increment (IAVI) on intra-abdominal hypertension (IAH) in the kidneys. Methods: Eight minipigs were successfully established as IAH models and were randomly divided into two groups: the IAVI group and the sham-operated group. The intravesicular pressure, inferior vena cava pressure and urine volume were measured before shock, 2 h after IAH, and 22 h after surgery, respectively. The following indices were measured: serum creatinine, urea nitrogen, renal cortical thickness, ratio of abdominal anteroposterior diameter/ transverse diameter, renal thickness, diameter of the renal sinus and the wet/dry ratio of renal tissues. Results: The intravesicular pressure (IVP) of the 8 minipig IAH models was calculated to be 21.16 ± 4.63 mmHg. There was a significant increase in the abdominal anteroposterior diameter/transverse diameter ratio. The minipigs in the IAVI group survived during the observational period, whereas 2 minipigs died at 18 h and 20 h in the sham-operated group. Twenty-two hours after surgery, the animals in the IAVI group displayed increased urinary volume (UV) and decreased Cr and Ur and remarkable decreases of VP and IVCP. After IAH, the renal cortical thickness and the renal thickness increased significantly. The renal wet/dry ratio in the sham-operated group was higher than that in the IAVI group. Conclusion: IAVI helps to control renal dysfunction after IAH, which may be related to lowering the intra-abdominal pressure, thus alleviating renal edema and blood stasis.