The Biocompatibility of a Cellulose Exopolysaccharide Implant in the Rabbit Bladder When Compared With Dextranomer Microspheres Plus Hyaluronic Acid.

Objective: To evaluate biocompatibility of a cellulosic exopolysaccharide (CEC) as bulking agent in rabbit urinary bladder.

Materials And Methods: The experimental study was developed at the Nucleus for Experimental Surgery or UFPE. The new agent was injected into the bladder of the adult rabbits using a small abdominal incision. Animals were injected with 0.2 mL of dextranomer microspheres (Dx) plus hyaluronic acid and CEC. The animals were studied after 3 days (G1), 90 days (G2), and 11 months (G3). The biocompatibility was evaluated according to the histologic parameters (presence of blood vessels, inflammatory reaction, and collagen deposition) by a quantitative analysis. The Student paired t test was used for continuous variables, and the scores were compared through the chi-square test.

Results: Both materials were structurally homogeneous and free from inflammatory cells or blood vessels (G1). In 3-month samples (G2), CEC areas were densely invaded by fibroblasts and blood vessels. Dx areas were fragmented but still homogeneous and free from cells or blood vessels. Samples from 3 and 11 months showed a significant difference in favor of CEC especially concerning preservation of material in the implant site, as well as the presence of neovascularization. This experimental study represents a positive outcome in terms of reflux resolution in the long term. Further studies may be necessary to confirm its efficacy when in clinical use.

Conclusion: The CEC exhibited low inflammatory response and integrated with the host tissue better than Dx in the long-term follow-up.