Safety and efficacy of fetal surgery techniques to close a spina bifida defect in the fetal lamb model: A systematic review.

OBJECTIVE

To determine the safety and efficacy of different neurosurgical techniques for closure of spina bifida (SB) in the fetal lamb model.

METHOD: Systematic review of studies reporting on fetal lambs undergoing induction and closure of SB compared with non-operated normal lambs (negative controls) and/or lambs not undergoing closure of the defect (positive controls). Primary outcomes were (1) survival at birth (safety) and/or (2) presence of Somatosensory Evoked Potentials on hind limbs and/or improvement in quantitative histological spinal cord findings and/or reversal of hindbrain herniation (efficacy).

RESULTS

Out of 1311, 36 full-text articles were eligible. Nineteen were included for quality assessment. Due to high bias, only 2 adequately powered studies were included in the final analysis. An open approach using a 2-layer closure (muscle flap or acellular-dermal-matrix patch plus skin) was the only safe (patch + skin) and effective (both techniques) technique for prenatal closure in this animal model. No comparable level of evidence was identified for other techniques.

CONCLUSION

The experimental literature on prenatal SB closure underscores the lack of standardization. At present, there is animal experimental evidence that a 2-layer closure by hysterotomy is safe and effective. This technique is currently clinically used in a subset of patients. As new clinical techniques are introduced, it would seem logic to preclinically validate them against this experimental standard.