The research described in this PhD thesis follows an extensive literature review of the role of the medical and surgical management of CRS. Despite the utilization of surgery to alleviate the symptoms of CRS refractory to medical therapy, there are clear deficiencies in our understanding of what type of surgery to perform, and how extensive this surgery should be so as to maximize long-term symptom alleviation and control. Particular controversy exists regarding addressing the frontal sinus with a wide variety of philosophies employed, but with limited scientific rationale to support such approaches. Chapter two describes a prospective study to validate a quality of life tool, the Adelaide Disease Severity Score. This study showed a simple 5 question tool directly related to sinus symptoms and visual analogue quality of life score correlated very highly with other more complex rhinological quality of life tools – the SNOT 20/22. It further correlated with radiological disease burden (Lund Mackay CT score) and endoscopic disease (Lund Kennedy endoscopic score) burden. This study validated our use of this tool to measure quality of life and symptom improvement in patients undergoing surgery. Chapter three describes a detailed retrospective study of the outcomes of primary frontal sinus surgery. This is the largest study in the literature of primary frontal surgery and forms the basis to support an approach where the diseased frontal sinus should be addressed surgically to optimize long-term outcomes. It also identified that certain anatomical factors such as a narrow frontal ostium seemed to play a role in persistence of symptoms. This raised questions as to whether these outcomes were as successful for revision and extended frontal sinus surgery. Were there identifiable risk factors for success and failure? The fourth chapter describes the outcomes of primary and revision standard frontal sinus surgery and investigates which patient, anatomical and disease factors were poor prognostic factors for failure. It identified a select cohort of patients that would benefit not just from frontal sinus surgery, but extended frontal sinus surgery (EMLP) in the first instance. The final chapter investigates the outcomes of extended frontal sinus surgery (EMLP) and seeks to determine the risk factors for its success and failure. This study found that the EMLP had excellent outcomes in the majority of patients, but there was a significant minority of patients that had persistence of symptoms. The relevance of the host immune system response to sinonasal microorganisms, and anatomical risk factors was also explored and lays open the basis for further study.Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 201
