Safety of untreated autologous cranioplasty after extracorporeal storage at − 26 degree celsius

Abstract

Background. Given the improved survival of patients requiring decompressive craniectomies, the frequency of subsequent cranioplasties are on the rise. The most feared complication of autologous cranioplasty is infection and one method for reducing the rate of infection, is to store the bone flaps at subnormal temperatures. However, to date there is no defined temperature for flap storage and temperature ranges from − 18 to − 83°C have been described in literature. Considering our limited resources it has been the practice at our center to store bone flaps at − 26°C. In this study, we have retrospectively reviewed our practice and have audited this choice of temperature with respect to the frequency of infections. Methods. A retrospective review was conducted for all cranioplasties performed at our center between January 2001 to March 2011, using autologous bone which was cryopreserved according to institutional protocol. During this period the operative and cryopreservation protocol remained the same. All patient records including charts, notes and laboratory findings were reviewed with a specific focus to identify infections. Results. Of the 88 patients included in the study, only 3 (3.40%) patients were found to show signs of infection. Of these, two patients had superficial surgical site infections which resolved with oral antibiotics (Co-Amoxiclav 1 gm BD for 7 days). However the third patient developed deep surgical site infection requiring re-exploration and washout. All three patients had complete resolution of infection with preservation of autologous bone. Conclusion. Despite our method of keeping the bone flap in freezer at − 26°C we have reported an acceptable rate of infection and raised the notion whether there is a justification for sophisticated and costly equipment for bone flap preservation, especially in resource depleted setups.