Enhancement Of Neointestinal Cyst Formation Using Abdominal Wall Musculature In A Rat Model
PANAGIOTIS TRYPHONOPOULOS1, WERVISTON DEFARIA1, MARIA B. TORRES1, PHILLIP RUIZ2,1, ANDREAS TZAKIS1; 1Surgery, University of Miami, Miami, FL; 2Pathology, University Of Miami, Miami, FL
Introduction The implantation of a suspension of rat enterocytes into the abdominal cavity of syngeneic animals results in the formation of a cyst containing neo-intestine. In this study we attempted to enhance the cyst formation by wrapping up the enterocyte suspension in a pouch made of abdominal wall muscle. Materials and methods: The intestine of neonate (6 to 8 days old) DA rats was removed and underwent enzymatic digestion with collagenase and dispase. The resulting organoid units were seeded on a polyglactin polymer absorbable mesh (100.000 units per mesh). The surface of the mesh was covered with the abdominal wall (muscle layer and fascia) that was harvested too from the donor rats, forming a muscular pouch around the mesh and enterocyte suspension. The pouch was then implanted at the peritoneal cavity of an adult syngeneic animal. The omentum of the recipient was sutured loosely around the pouch to assure its vascularization. Animals were sacrificed 4 weeks later and implants were harvested for histologic studies. Paraffin sections of the formed cysts were stained with hematoxylin and eosin for microscopy observation. Results: Our previous experience, consisting of the implantation of the mesh containing the cell suspension, showed that many of the cells dispersed through the mesh in the peritoneal cavity. This would lead sometimes to the formation of multiple small cysts or a multilobulated larger cyst, that were not adequate to work with to study the neo-intestinal function. Using this new method, enterocyte dispersion was minimized and as a result we obtained single cysts, larger than those of our previous experience. On histological examination, that cyst consisted of a muscular wall and its lumen contained intestinal epithelium with villi. The cyst was vascularized by the omentum. Conclusion: The implantation of rat enterocyte suspension in the abdominal cavity of syngeneic animals in a pouch made from abdominal wall musculature, minimizes cell dispersion and leads to the development of a single large cyst. The wall of this cyst is made of muscle tissue and its lumen is lined by intestinal neo-epithelium. Its large size allows us to better study in vivo the properties of the neo-formed intestinal epithelium.
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