title: Observations on the mode of action of an intratubal device, the P-block.
abstract: A hydrogelic intratubal device, called P-block, Mark 9, was inserted hysteroscopically with local anesthesia in the intramural part of the fallopian tube of 25 women referred for the procedure as an alternative to abdominal sterilization. Hysterosalpingography revealing bilateral oviductal patency was followed by hysteroscopic checkup verifying bilateral presence of P-blocks, except in three patients who had expulsion of the P-blocks on one side. All of the 22 patients had retention of the P-blocks 6 to 7 months after insertion. None became pregnant. Thus it is suggested that an intratubal device in the isthmic part of the human fallopian tube acts as an intrauterine contraceptive device, preventing intratubal and intrauterine pregnancies. Endeavors to explain the contraceptive effect of a nonocclusive intratubal device are discussed on the basis of our present knowledge of tubal physiology. Distension of part of the human isthmus is likely to disturb normal gamete transport through the isthmus.
mesh_terms: D000328:Adult; D019723:Endoscopes; D004724:Endoscopy / Q000379:methods; D004867:Equipment Design; D005186:Fallopian Tube Patency Tests; D005187:Fallopian Tubes; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007047:Hysterosalpingography; D007433:Intrauterine Device Expulsion; D007434:Intrauterine Devices; D011092:Polyethylene Glycols
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols