A new biocompatible material (Lyoplant) for the therapy of congenital abdominal wall defects: first experimental results in rats.

Congenital abdominal wall defects are impressive and dramatic malformations. Common surgical therapy for omphalocele and gastroschisis is to place the herniated viscera back into the abdomen and to close the fascia. Small defects can be closed directly by surgical treatment. In large defects, resorbable and non-resorbable artificial materials are necessary to close the fascia. The aim of this study is to find out whether new biocompatible materials might be suitable for the treatment of such abdominal wall defects. A median laparotomy was performed in young Wistar rats with a body weight of 75-100 g. Then a full thickness defect was created by excising a 1.5 x 2.5 cm segment including fascia, muscles and peritoneum. These defects were then closed by implantation of a PTFE mesh (Dual-Mesh, n = 6), a PPP mesh (Prolene, n = 6) or a new biocompatible mesh (NBM; Lyoplant, n = 6). Each rat was examined daily after treatment. Bodyweight was determined and the possible development of a hernia was monitored. After 6 weeks, the abdomen was opened again. Adhesions to the intestine were measured and the abdominal wall was removed for histological and tensiometric examination. (1) Compared to the untreated controls, all animals showed physiologic growth and normal bodyweight curve. (2) Only in one rat (Prolene) did an abdominal hernia develop. (3) In contrast to PTFE and PPP mesh, NBM showed only minimal adhesion to the intestine. (4) Tensiometry revealed high stability for non-resorbable materials. However, the characteristics of NBM were very similar to untreated abdominal wall. Our initial results indicate that biocompatible materials can also be used for the therapy of congenital abdominal wall defects.