PUBIC SYMPHYSIS REPAIR STRENGTH IN SIMULATED BLADDER EXSTROPHY USING A SHEEP MODEL

Objectives. To investigate the mechanical strength of various pubic sy mphysis suture material in a simulated animal model of neonatal bladde r exstrophy. Methods. Neonatal lamb pelves, which are the approximate size of neonatal human pelves, were used. Twenty-four neonatal lamb pe lves were divided into four equal groups. A midline symphysotomy was m ade through the cartilaginous pubic symphysis in three groups and repa ired using two figure-of-eight sutures (size 0) placed through the car tilaginous pubis using polypropylene, braided polyester, or polyglacti n. The fourth group served as the control. The pelves were then tested to ultimate load in pure tension at a strain rate of 0.25 mm/s until failure. Results. There was a highly significant difference between th e intact specimens and the repaired specimens (P = 0.0008). For the re paired specimens, there was a significant difference in the ultimate l oad normalized by pubic height between those repaired with polypropyle ne and polyglactin (P = 0.025), but not for those repaired with polypr opylene and braided polyester (P = 0.11) or braided polyester and poly glactin (P = 0.11). Conclusions. Braided resorbable sutures are recomm ended for pubic symphysis repair, because they have a lower tendency t o cut out of the cartilage. UROLOGY 52: 336-340, 1998. (C) 1998, Elsev ier Science Inc. All rights reserved.