In the cecal sidewall adhesion model, an incision is made into the peritoneal space. The cecum is externalized and abraided by gently rubbing with sterile gauze until puncate bleeding is observed. Simultaneously, a small defect in the peritoneal lining is created, proximal to the cecal abraision.

For drug treatments, application of the test article can be before, during or after the surgical procedure, depending on the drug's mode of action. For coated implants, they are generally sutured in place covering the peritoneal defect placing them in apposition to the abraided cecum.The cecum is returned and the surgical incision is closed.

After the specified duration (anywhere between 7 and 14 days and often in a time-course with multiple time-points), the animal is euthanized and the peritoneum is re-opened to assess the degree of adhesion formation, as shown in the pictures below.

The rabbit cecal sidewall adhesion model is, in our experience, an extremely sensitive model for adhesion formation. This sensitivity is, simultaneously, the model's biggest advantage and disadvantage. The model tends to produce "all or nothing" results with good performing test articles reducing the amount of adhesion formation from 100% in controls, to 70%-0%. The fact that even good performing materials may still have up to 70% adhesions is sometimes frustrating to customers, but with suitable animal numbers (and given the fact that this model represents a "worst case" scenario) the model is highly effective and reproducible and can produce statistically significant results.

It should be noted that an alternative to the rabbit cecal sidewall adhesion model is a similar model in rats. However, BRIDGE PTS has found this model to be extremely unreliable. Publications that describe this model often describe multiple adhesions that can be enumerated to show differences between tests and controls. However, our experience is that these adhesions are often extremely loose and may tear during the preparations for assessments. As such, we discourage the use of the rat variation of this model for our customers.

1. Orita H, Fukusawa M, Girgis W, diZerega GS. Inhibition of postsurgical adhesions in a standardized rabbit model: intraperitoneal treatment with tissue plasmogen activator. Int J Fertil. 1991 May-Jun;36(3):172-7.