Confirmation of Biologic Ingrowth into a Polyester Matrix in the Endometrial Cavity in an Animal Model

Abstract

Study Objective: To determine the ability to achieve biologic ingrowth into a polyester matrix in the endometrial cavity in an animal model. The purpose of this is to allow further investigation into the use of polyester to promote biologic ingrowth into the endomyometrium near the uterotubal junction for sterilization purposes. Design: Devices were inserted into four Nubian goats on the same day. Because of anatomic differences from the human model, the devices could not be placed transcervically. A device was placed in each horn via a small hysterotomy incision and secured with non-reactive suture material. The animals were recovered. The uterus was removed from a goat on each of the successive four weeks. The uteri were sent to a pathology lab with expertise in staining for biologic ingrowth. Serial sections were obtained and stained to determine the degree of biologic ingrowth into the polyester matrix. Setting: The devices were inserted into the animal models in a qualified veterinary surgical facility. Measurements and Main Results: Pathologic determination of progressive biologic ingrowth into the polyester matrix was confirmed. By Week 1, early ingrowth was readily identified. By Week 4, ingrowth of tissue into the polyester matrix was confirmed, with the endometrium essentially replaced by ingrowth. The ingrowth provided contact of the polyester to an depth close to the myometrium. Conclusion: Biologic ingrowth into a polyester matrix can be acheived in the endometrial cavity. With the local destruction of the endometrial layer and ingrowth to a depth approaching the myometrium by Week 4, there should be no concern about the device being expelled during menses. Further investigation into the usefulness of this finding is necessary to determine if the concept can be applied to a transcervical sterilization device.