Nonvascularized Bone Graft Reconstruction of the Irradiated Murine Mandible

Autor: Steven R. Buchman, Noah S. Nelson, Joseph E. Perosky, Russell E. Ettinger, Alicia Snider, Kevin M. Urlaub, Yekaterina Polyatskaya, Jessie M Hoxie, Alexis Donneys
Rok vydání: 2019
Předmět:
Zdroj: Journal of Craniofacial Surgery. 30:611-617
ISSN: 1049-2275
DOI: 10.1097/scs.0000000000005032
Popis: Nonvascularized bone grafts (NBGs) represent a practical method of mandibular reconstruction that is precluded in head and neck cancer patients by the destructive effects of radiotherapy. Advances in tissue-engineering may restore NBGs as a viable surgical technique, but expeditious translation demands a small-animal model that approximates clinical practice. This study establishes a murine model of irradiated mandibular reconstruction using a segmental iliac crest NBG for the investigation of imperative bone healing strategies. Twenty-seven male isogenic Lewis rats were divided into two groups; control bone graft (CBG) and irradiated bone graft (XBG). Additional Lewis rats served as graft donors. The XBG group was administered a fractionated dose of 35Gy. All rats underwent reconstruction of a segmental, critical-sized defect of the left hemi-mandible with a 5mm NBG from the iliac crest, secured by a custom radiolucent plate. Following a 60-day recovery period, hemi-mandibles were evaluated for bony union, bone mineralization, and biomechanical strength (p < 0.05). Bony union rates were significantly reduced in the XBG group (42%) compared to controls (80%). Mandibles in the XBG group further demonstrated substantial radiation injury through significant reductions in all metrics of bone mineralization and biomechanical strength. These observations are consistent with the clinical sequelae of radiotherapy that limit NBGs to non-irradiated patients. This investigation provides a clinically relevant, quantitative model in which innovations in tissue engineering may be evaluated in the setting of radiotherapy to ultimately provide the advantages of NBGs to head and neck cancer patients and reconstructive surgeons.
Databáze: OpenAIRE