Reconstruction of Cranial Vault With Autologous Graft in Combination With Allogeneic Bone-Plastic Material and Platelet Lysate in Delayed Cranioplasty

INTRODUCTION In patients with cranial vault defects autologous cranioplasty with the bone flap is often accompanied by flap lysis. Bio-conductive factors, including additional biological structures and drugs, can be used to stimulate osteogenesis and integration of the bone flap. THE AIM OF THE STUDY To evaluate the safety of using a modified autologous cranial graft combined with bone-plastic material (BPM) and autologous platelets´ preparations, as well as the dynamics of cranial vault reconstruction in patients with delayed cranioplasty. MATERIAL AND METHODS 7 patients, aged from 32 to 69 years, with diagnoses involving delayed cranioplasty were examined and treated. To increase the bioconductive properties, the bone flap was perforated, saturated with 0,8% allogeneic solution of human type 1 collagen, lyophilized, sterilized with ionizing radiation and stored at 20–22°C. The diastasis region was filled with allogeneic BPM, consisted of 0,8% human type 1 collagen and bone chips. Autologous platelet lysate was used to stimulate the revitalization of the cranial graft. The assessment of reparative processes was performed by multispiral computed tomography (CT) and three-phase osteoscintigraphy after 6, 12 and 18–24 months. RESULTS In all the patients, the postoperative period was uneventful. Edges of the bone flap maintained their stability during all time of observation. In 6 of 7 patients the appearance of bone bridges was observed after 6 months, which led to formation of consolidation sites within 12–24 months. The X-ray density of the bone flap decreased slightly after 12 months without pronounced signs of flap lysis. In the postoperative period, steady decrease in the size of diastasis was noted from 2,0 (2,0; 3,1) mm to 0,9 (0,8; 1,5) mm after 18–24 months. Three-phase scintigraphy showed intensification of blood flow in the bone flap after 6–12 months, which was normalized by 12–24 months. Thus, active repair and regeneration of bone tissue in the area of diastasis began after 6–12 months and lasted for 18–24 months, followed by stabilization of the bone flap. CONCLUSION The use of autologous cranial graft in combination with allogeneic bone-plastic material and platelet preparations was safe for delayed cranioplasty. Within 24 months after surgery, high preservation of the bone flap is observed, followed by gradual regeneration and consolidation of the bone in the diastasis area, which could be observed by CT and three-phase scintigraphy.