Establishment of colonic dialysis model in uremic rats by right nephrectomy and left partial nephrectomy

Conventional treatments for patients suffering with end-stage renal disease (ESRD) has several disadvantages, highlighting the importance of other reproducible modalities such as colonic dialysis (CD).

The aim was to establish a CD model in uremic rats and evaluate the effect of two different peritoneal dialysis (PD) solutions.

Thirty-two male Wistar rats were randomly divided into four groups. After right nephrectomy and left partial nephrectomy, a Malone antegrade continence enema (MACE) stoma was created. Seven days after the procedure, blood sampling was performed. In group I (N = 8) no postoperative intervention was performed. In group II (N = 8), CD was started through the MACE stoma by a low osmolar PD solution. Rats of group III (N = 8) underwent the same procedure with a high osmolar PD solution. Rats of group IV (N = 8) underwent CD without nephrectomy in order to evaluate the feasibility of this technique. Mannitol and activated charcoal were also added to both PD solutions. Weekly blood sampling was performed in order to evaluate the plasma creatinine and blood urea nitrogen (BUN) level.

In rats of the control group, the respective mean ± SD creatinine level was 1.5 ± 0.04 mg/dL, 7 days after the surgical procedure, but a lower creatinine level was found in groups II and III (0.8 ± 0.02 and 0.5 ± 0.03, respectively). Despite the fact that the creatinine level was in steady low states after regular CD in group II (1 ± 0.05) and group III (0.6 ± 0.02), it remained at higher levels in the control group (1.7 ± 0.08) 2 weeks postoperatively. Rats of group I did not survive until the third postoperative week, while the creatinine level was still lower in group III than in group II (0.6 ± 0.02 vs. 1.1 ± 0.03). Similar results were obtained for the BUN level at these timepoints. The mean ± SD survival period was 11 ± 2, 20 ± 3, and 33 ± 2 days in the animals of groups I, II, and III, respectively.

To the best of our knowledge, this is the first study of CD establishment in a rat model. Unfortunately, the amount of protein loss, elevation of blood glucose levels, and electrolyte disturbance were not evaluated in the current study because of the limited amount of blood samples. Disturbance of these factors might be a cause of mortality in experimental groups undergoing CD while a significant decrease in BUN and creatinine levels was obtained.

CD with an efficient PD solution through a MACE stoma may be a valuable option when conventional methods are not available.