Pediatric cranio-facial surgery. First-year's experience with a gun applying bioabsorbable tacks

AIM: In 2001 a prototype of a gun to apply bioabsorbable tacks in cranio-facial surgery has been developed. METHODS: From May 2001 to May 2002 this device has been used in the University Hospital of Innsbruck (Austria) for different cranioplasty procedures, in 34 children, showing its reliability for cranio-facial bone fixation. The children were affected by isolated craniosynostosis or by syndromical synostosis (Apert, Crouzon) and in a case of benign tumor of the parietal skull vault. The range of age, at the time of surgery, was between 3 months and 204 months of age. Bone segments were fixed using self-reinforced polylactide plates and tacks. RESULTS: Firm fixation was obtained intra-operatively and the operative time was reduced about 25-30 minutes as compared to use of plates and screws. This device has just one limitation in its own spring force: sometimes the bone thinner than 1 mm has been broken applying the tacks. CONCLUSION: After the first-year's experience it is possible to confirm that this device reduces, in selected cases, operative time, blood loss, risk of infection and, as a result, the costs.

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

Electronic absorption and fluorescence spectra based on transmission measurements of thin layers obtained from new perylene−zeolite L composites and new dye1,dye2−zeolite L sandwich composites, the latter acting as antenna systems, have been investigated and analyzed. The influence of extra- and intraparticle self-absorption on the spectral shape and fluorescence quantum yield is discussed in detail. Due to its intraparticle origin, self-absorption and re-emission can often not be avoided in organized systems such as dye−zeolite L composites where a high density of chromophores is a prerequisite for obtaining the desired photophysical properties. We show, however, that it can be avoided or at least minimized by preparing dye1,dye2−zeolite L sandwich composites where donors are present in a much larger amount than the acceptors because they act as antenna systems.