Morphometric Features of the Latissimus Dorsi Muscle in Fetal Cadavers With Meningomyelocele for Prenatal Surgery.

Purpose: Latissimus dorsi (LD) flaps are frequently used in the prenatal meningomyelocele (MMC) repairs; on that basis, this study aims to reveal the morphometric features of LD, thoracodorsal artery (TDA) and nerve (TDN) in fetal cadavers with MMC defects, with an anatomical perspective.

Methods: The study was conducted on 7 formalin-fixed human fetal cadavers (4 males and 3 females) with MMC defects, aged from 18 to 27 weeks of gestation. The size of LD, TDA, and TDN including their area, length, and width were measured by a digital caliper and digital image analysis software. Our direct measurements were compared with the corresponding estimations of a previous study in the literature which provides regression formulae based on gestational age.

Results: The fetal cadavers with MMC had bilateral LD. No significant differences were found in the numerical data of anatomical structures between the sides or the sexes. LD size (ie, area, length and width) was approximately 3% to 10% smaller in the fetuses with MMC defects than that of the normal fetuses. Unilateral LD flap in a 22-week-old fetus with a large MMC was evaluated as insufficient to close the defects.

Conclusion: Ten percent shrinkage in the area of LD might be too critical to be disregarded by surgeons during the closure of MMC defects. The dimensional findings about LD (area, length, and width) may be helpful in planning of LD flap harvesting for the repairs of MMC.