LACK OF DISTANT MIGRATION AFTER INJECTION OF A (125)IODINE LABELED DEXTRANOMER BASED IMPLANT INTO THE RABBIT BLADDER

Purpose: In recent years endoscopic treatment of stress incontinence a nd vesicoureteral reflux has been Introduced. Reports of possible part icle migration of the injected material to distant organs in humans an d experimental animals have led to a search for biological nonmigratio n products. An implant found to have a good clinical effect in these c onditions is dextranomer in hyaluronan. We performed this study in rab bits to investigate the possible migration of dextranomer particles. M aterials and Methods: (125)Iodine labeled dextranomer particles were i njected into the submucosal space of rabbit bladders, and samples of b lood and various tissues were examined for radioactivity at scheduled intervals during a 28-day period. Furthermore, whole body autoradiogra phy was performed 1 day, and 1 and 4 weeks after injection. Results: R adioactivity was found in blood samples and in all tissues but it rema ined at the background activity level except in the thyroid, where upt ake representing free (125)iodine was detected. In the bladder 41 and 45% of the injected dose remained within the bladder wall 1 day and 4 weeks, respectively, after injection. The remainder of the dose probab ly disappeared from the bladder wall by leakage into the urine shortly after deposition, as indicated by the finding of 10-fold higher urine radioactivity levels at day 1 than at day 28 after injection. Conclus ions: No distant migration of dextranomer particles occurs after submu cosal injection of such an implant in the rabbit bladder wall.