Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

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Surgeons have constantly sought to achieve the most aesthetic scar. A major factor determining the final cosmetic appearance of a cutaneous scar is the tension acting on the wound edges during the healing phase. Since Theodor Kocher pioneered the alignment of skin incisions with Langer's lines in 1892, surgical techniques that attempt to overcome closing tension have become standard. Yet, no treatment has been available to minimize underlying muscle contractions, which are the major cause of this tension. Botulinum toxin A is a potent drug that produces temporary muscular paralysis when injected locally. It has proven to be safe and effective in the treatment of a variety of disorders, including hyperkinetic facial lines. The objective of this randomized, double-blind, placebo-controlled primate study was to investigate the efficacy of a single injection of botulinum toxin A to improve the cosmetic appearance of cutaneous scars. Symmetric pairs of standardized excisions were performed on either side of the forehead of six primates. The half foreheads were randomized to the botulinum toxin A treatment side versus the placebo injection side. A panel of three blinded facial surgeons assessed the cosmetic appearance of the mature scars 3 months postoperatively. The wounds that had been immobilized with botulinum toxin A were rated as significantly better in appearance than the control wounds (p < 0.01). Histologic examination confirmed that all scars were mature. Blinded, randomized, placebo-controlled human clinical trials are presently under way at the Mayo Clinic.

A persistent cerebrospinal fluid (CSF) leak is potentially lethal, and surgical treatment is often required. CSF leak repair is an infrequently performed procedure, and only limited information is available on the long term success of the surgical techniques that are used. This retrospective chart review includes 95 patients who underwent various types of repair surgery for CSF rhinorrhea at the Mayo Clinic. The purpose of this study was to extract factors such as the choice of sealing material, etiology, location of defect(s), surgical approach, and previous procedures, and to analyze their association with the long term success and failure of surgical repair. The mean time interval in this study between unsuccessful surgery and recurrence was 50.8 months, and the mean follow-up 109 months. Among the various approaches, defects repaired endonasally had the lowest recurrence rate. Local nasal mucosa advancement flaps failed more frequently (83.3% failure) than other types of graft material (p = 0.023). These failures took place in a delayed fashion (mean interval until failure: 80 months). Local osteo-mucoperiosteal or chondro-mucoperichondrial flaps (22.2% recurrence rate) and free graft material (15.6% recurrence rate) had the best outcome. The use of fibrin glue to fixate free grafts did not improve the result in this series. Transcranial procedures were associated with a higher complication rate than extracranial procedures (12.9% versus 3.2%). Overall, successful repair was achieved in 91.6% of the patients. We discourage the use of mucosa advancement flaps and advocate free grafts or pedicled osteomucoperiosteal or chondro-mucoperichondrial flaps as sealing material of choice in the majority of cases. The occurrence of delayed failure has to be considered when evaluating reports of CSF rhinorrhea after surgical repair.