A Different Technique to Create a ‘Myelomeningocele-Like’ Defect in the Fetal Rabbit

Abstract

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.

Anesthetic management in intrauterine surgery to evaluate an experimental model of myelomeningocele in non human primates (Macaca mulatta)

“…In the last years there has been diverse research in animals, like the one performed by Heffez et al 6,7 , in rats, Pedreira et al 8 . in rabbits, Meuli et al 9 in sheep, Pedreira et al 10 in ovine fetuses and Michjeda 11 in non human primates Macaca mulatta; creating intrauterine surgical models to reproduce different diseases and perform its correction.…”

Validation of the ovine fetus as an experimental model for the human myelomeningocele defect

“…With the objective of utilizing the endoscopic approach in correcting myelomeningocele, we attempted to simplify the classic neurosurgical technique, which we consider difficult to employ via endoscopy. To do so we used the rabbit fetus, and in the first study [8][9] , we modified the defect-producing technique. In the second study 10 , we successfully developed a new corrective technique, using cellulose film to cover the deformity.…”

Biosynthetic cellulose induces the formation of a neoduramater following pre-natal correction of meningomyelocele in fetal sheep

“…BC was used as a dura-mater substitute by Mello et al 14 in dogs submitted to craniotomies, with encouraging findings. After this, Pedreira et al (2003) 16 successfully tested BC in rabbit fetuses for MMC repair. Mello et al 14 stated that the BC might be dissolved in tissue alkalis, however, during a maximum 270 day period, they found no evidence of BC digestion or absorption.…”

“…The same perioperative conditions used for the defect creation were repeated for the corrective procedure up to the point of fetal back exposure. Both materials were applied over the damaged neural tissue according to the previously developed technique used in the fetal rabbit model 16 . Briefly, we under cut 1.0 cm of the skin beyond the margins of the defect and placed either HADM or BC over the exposed neural tissue and under the skin edges; skin was then approximated to cover all the material (Figure 1).…”

“…This Brazilian manufactured membrane is a low-cost material that has been used in plastic surgery as a temporary skin substitute for second degree burns. BC has been used during corrective surgery to cover the exposed spinal cord in a fetal rabbit model and showed no signs of rejection 16 . The aim of this study is to compare the effectiveness of HADM and BC in protecting neural tissue after in utero surgery to correct experimentallyinduced MMC in a fetal ovine model.…”