Successful fetal surgery for the repair of a 'myelomeningocele-like' defect created in the fetal rabbit.

OBJECTIVE: To study the correction of a 'myelomeningocele-like' defect in fetal rabbits. METHODS: Twelve pregnant rabbits had a spinal defect surgically created in 40 of their fetuses at 23 days of gestation. Immediate repair was performed in 30 fetuses (group I), and 10 remained uncorrected (group II). After 30 days, the fetuses were harvested and the anatomopathological aspects where compared using Fisher's exact test. RESULTS: Three different techniques to apply a cellulose graft were used for correction in 8 (technique A), 7 (technique B), and 15 animals (technique C), but only one (technique C) was successful. The survival rate at 30 days was 66.7% (10/15) in group I and 80% (8/10) in group II. A 'myelomeningocele-like' defect was present in all fetuses in group II, while in group I the defect was successfully repaired in 80% of the surviving fetuses (p < 0.01). CONCLUSION: The surgically created spinal defect was successfully repaired, and also the fetal rabbit could be established as a model for the study of intrauterine correction of a myelomeningocele-like defect.

Estudo de uma nova técnica para criação cirúrgica de um defeito semelhante a meningomielocele em fetos de coelhos / Study of a new technique to surgical create of a myelomeningocele like defect in the fetal rabbit

OBJETIVO: Avaliar a sobrevida fetal usando uma nova técnica cirúrgica para criação de um defeito semelhante a meningomielocele em fetos de coelho. MÉTODOS: Foram utilizadas seis coelhas da linhagem Nova Zelândia que tiveram um defeito espinhal criado em seus fetos no 23º dia de gestação. O defeito foi criado em 19 fetos e a tentativa de correção foi feita em 15 casos (grupo I), 4 fetos permaneceram sem correção (grupo II). No 30º dia de gestação, os fetos foram submetidos a avaliação anátomo-patológica. RESULTADOS: No 30º dia a meningomielocele estava presente em todos os fetos sobreviventes. A sobrevida total foi de 73,68 por cento (14/19), 11 fetos sobreviveram no grupo I, e 3 no grupo II. CONCLUSÃO: A técnica modificada apresenta sobrevida fetal satisfatória, no modelo experimental de criação de defeito espinhal em fetos.

A different technique to create a 'myelomeningocele-like' defect in the fetal rabbit.

OBJECTIVE: To evaluate the fetal survival rate using a modified technique to surgically create a 'myelomeningocele-like' defect in a rabbit model. METHODS: Six white New Zealand rabbits had a spinal defect created in their fetuses at 23 days of gestation. At 30 days of gestation, the fetuses were harvested for anatomo-pathologic evaluation. RESULTS: The defect was created in 19 fetuses and an attempt to correct it was made in 15 cases (group I), and 4 fetuses where left without correction (group II). At 30 days, a 'myelomeningocele-like' defect was present in all surviving fetuses. The total survival rate was 73.68% (14/19); 11 fetus survived in group I and 3 in group II. CONCLUSION: The technical modifications, including fetal positioning and exposure of its back prior to the incision of the lamina, associated with a different technique for myometrium closure, offer an alternative and probably safer method to surgically create a spinal defect in the fetal rabbit.