Allogeneic fetal bone cranioplasty in Macaca mulatta.

Area of Science:

• Veterinary Surgery
• Developmental Biology
• Neuroscience

Background:

• Teratogen exposure can cause neural tube defects like encephalocele.
• Encephalocele, a herniation of the occipital lobes, is often associated with cranium bifidum.
• Surgical intervention is necessary for managing these congenital abnormalities.

Purpose of the Study:

• To evaluate the efficacy of in utero and postnatal surgical repair of teratogen-induced encephalocele in non-human primates.
• To assess the viability and integration of fetal allogeneic cranial bone grafts for cranioplasty.
• To determine the optimal timing for cranioplasty to ensure successful graft integration and cosmetic outcomes.

Main Methods:

• Monkey fetuses (Macaca mulatta) with teratogen-induced encephalocele underwent surgical repair.
• Cranioplasty was performed using fresh frozen fetal allogeneic cranial bone and bone paste.
• Repairs were conducted either in utero or at different postnatal stages (1-2 weeks vs. 2-3 months).

Main Results:

• Early repair (in utero or 1-2 weeks postpartum) resulted in strong bone graft union with the calvarium.
• Early repairs provided excellent protection for neural tissue and dura, with smooth surfaces.
• Cranioplasty performed at 2-3 months of age led to bone graft rejection.
• Good cosmetic-reconstructive results were achieved with early surgical intervention.

Conclusions:

• Early surgical intervention, including in utero or immediate postnatal cranioplasty, is crucial for successful encephalocele repair in primates.
• Fetal allogeneic bone grafts are effective for cranioplasty when performed during the early developmental window.
• Delayed cranioplasty significantly increases the risk of graft rejection, highlighting the importance of timing in reconstructive surgery for congenital defects.