A comparative study of four permanent cannulation procedures in rats

Permanent implantation of vascular catheters allows multiple blood sampling from the experimental animal. The aim of the study was firstly to establish four cannulation procedures in rats, which will result in high rate of catheter patency after the post surgical recovery period and secondly to determine a suitability of food and water consumption (FC and WC) and body weight gain (BW) as markers for the estimation of the length of recovery period.

Cannulation of the jugular vein (n=12), femoral vein (n=15), ileocolic vein (n=13) and the dual cannulation of the jugular vein/duodenum (n=7) were performed in the rat. Catheter patency was monitored throughout the recovery period. Rats were considered fully recovered after return of BW, FC and WC to the preoperative values.

A decrease of catheter patency in the recovery period followed a linear regression model in all cannulation groups (P<0.01, R(2)>0.87). BW significantly decreased in the rats subjected to ileocolic and jugular/duodenum cannulation procedures only. A significant transient decrease of FC and increase of WC was observed in all cannulation groups. FC returned to the preoperative values more slowly than BW and WC. Therefore FC was considered as the most sensitive parameter for the estimation of the length of recovery period, resulting in the recovery period of 10 days and catheter patency of 75-85% in the case of jugular vein, femoral vein and dual jugular vein/duodenum cannulation procedures. After the cannulation of the ileocolic vein FC did not return to the preoperative values.

The catheter patency at the end of recovery period, which was estimated by the FC, was assured in the majority of rats in all cannulation groups, with the exception of the ileocolic vein cannulation group. In this particular cannulation group FC did not return to preoperative values, thus indicating that further optimization of the ileocolic vein cannulation procedure is required.