Distal Aortic Perfusion and Theophylline in the Augmentation of Postischemic Renal Blood Flow

Abstract

This study was designed to determine the efficacy of pulsatile versus nonpulsatile perfusion in augmenting renal blood flow following renal ischemia. Theophylline was added to assess the additive effect on postischemic renal blood flow. A porcine model was divided into six experimental groups encompassing a total of 48 pigs. Each group underwent cross clamping of the suprarenal aorta for 60 minutes. The control group underwent cross clamping of the suprarenal aorta without femoral cannulation and half of this group received theophylline. The remaining four groups underwent cross clamping of the suprarenal aorta and were placed on pulsatile or nonpulsatile distal perfusion with or without theophylline. Theophylline (2 mg/kg) was administered 30 minutes before the cross clamping of the suprarenal aorta. Renal blood flow was measured by utilizing a flow probe placed on the renal artery and data were recorded for 20 minutes. Baseline recordings were taken as well as recordings during cross clamp and immediately postclamp. Renal ischemia was measured by using serum urea nitrogen, serum creatinine, and urine alpha glutathione-S-transferase (alpha-GST).

Postclamp renal blood flow measurements were standardized as a percentage of preclamp renal blood flow. Treatment with either distal perfusion or distal perfusion with theophylline demonstrated increased renal blood flow in comparison to the controls (p < 0.001). Pulsatile perfusion with theophylline was superior to pulsatile perfusion alone (p < 0.023). Pulsatile perfusion with theophylline was superior to nonpulsatile perfusion with theophylline (p < 0.030). Creatinine 6 hours postoperative showed a significant decrease with both forms of distal aortic perfusion when compared to the control groups (p = 0.002). Creatinine values at 18 hours postoperative were not significant (p = 0.237). Serum urea nitrogen values at 6 (p = 0.239) and 18 (p = 0.460) hours postoperative were not significant. Alpha-GST values at 6 (p = 0.034) and 18 (p = 0.035) hours postoperative showed a significant difference between the control and treatment groups.

Pulsatile distal aortic perfusion with theophylline is superior to nonpulsatile distal aortic perfusion with theophylline in augmenting renal blood flow following renal ischemia in the porcine model.