Inert patch with bioadhesive for gentle fetal surgery of myelomeningocele in a sheep model.

OBJECTIVE: Current techniques used in foetal myelomeningocele repair can require considerable manipulation of fragile foetal tissues to obtain tension-free closure. The aim of this study was to assess the feasibility of a simple foetal coverage method without foetal tissue manipulation to provide closure of the neural tube defect in myelomeningocele. STUDY
DESIGN: This is an experimental study performed in 15 foetal sheep with lumbar myelomeningocele, surgically created on day 75 of gestation. Five foetuses remained untreated. Ten underwent coverage with inert sheeting (5 Silastic; 5 Silastic+Marlex) secured by surgical tissue adhesive without suturing on day 95; none of them underwent foetal muscle or skin manipulation. Clinical and subsequent histological examinations were performed at 48h after birth. The Chi-square, Fisher exact, and Mann-Whitney U tests, when appropriate, were used for the comparisons.
RESULTS: The mean operating time for foetal coverage was 7.1 (SD=1.6)min. All untreated animals were unable to walk, had sphincter incontinence, showed an open defect, histological spinal cord damage, and a large Chiari malformation. All covered animals were able to walk, had sphincter continence, showed almost complete closure of the defect with regeneration of several soft tissue layers, and minimum Chiari malformation.
CONCLUSION: In a surgical myelomeningocele model in sheep, a simple, fast and gentle coverage method using a sealed patch avoids foetal tissue manipulation and enables adequate closure of the neural tube defect, providing regeneration of several tissue layers that protect the spinal cord, and significantly reducing Chiari II malformation.