4 LAYER VERSUS 1 LAYER SMALL INTESTINAL SUBMUCOSA FOR CORRECTION OF PENILE CHORDEE: EXPERIMENTAL STUDY IN A RABBIT MODEL

Abstract

We evaluated the use of 4 vs 1 layer small intestinal submucosa (SIS) for covering defects in the ventral surface of the tunica albuginea to correct severe chordee. A total of 18 New Zealand white rabbits underwent implantation of a 10 x 5 mm SIS graft following excision of a rectangular area in the ventral surface of the tunica albuginea. In 9 rabbits 4 layer SIS was used to cover the defect and in the remaining animals 1 layer SIS was used. The animals were sacrificed at 2, 6 and 12-week intervals postoperatively, respectively. The surface area of the grafts was measured and the percent of contracture was calculated. Transverse sections of the penis at the graft site were stained with hematoxylin and eosin, and Masson's trichrome, and examined microscopically. : None of the animals had hematoma or bleeding. At autopsy contracture was not seen in any of the rabbits with 1 layer SIS. On the contrary, there was 21% and 25% contracture at 6 and 12 weeks, respectively, in the 4 layer SIS group. At 12 weeks the 1 layer SIS graft was completely replaced by well collagenized tissue similar to that of normal tunica albuginea without inflammatory infiltrate, while the multilayer SIS graft was replaced by dense fibrous tissue with areas of chronic inflammation and other focal areas of calcification. Four layer SIS undergoes contracture and calcification when used to cover defects in the tunica albuginea. On the other hand, 1 layer SIS can be safely and reliably used for corporeal grafting.