Team sinus 21st March 2012
Since the 1980s, the subspecialty of rhinology has evolved faster than any other discipline within otolaryngology. Just twenty-five years ago, medical therapy for rhinosinusitis focused almost exclusively on antibiotics, with failure resulting in sinus surgery performed through a variety of external incisions, extensive mucosal loss and a long recovery was required. Our pathophysiological understanding of chronic sino-nasal conditions has progressed from simple models of obstruction and airflow, to a more comprehensive understanding of mucosal health and inflammation of a “unified airway”. Much of the sinus surgery performed today is done via the nose, with an endoscopic approach, and recovery time is similar to that required from a simple common cold. The treatment of tumours in and around the paranasal sinuses has also evolved. Many tumours resections, which were routinely performed with disfiguring transfacial incisions and large craniotomies, also utilise the endoscopic approach. It is these innovations in both surgical and scientific knowledge that have led to greater clinical insight and allowed rhinology to develop into a recognised and respected subspecialty.

There are two main themes to our research program:

1. Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is highly prevalent in the community affecting patients of all ages and leads to frequent visits to primary and specialist care.  Estimates from the National Health Survey indicate that, based on respondents’ self-reports, just under 2 million people in Australia (9% of the Australian population 21,498,5403)  had chronic sinusitis in 2007-2008. This makes CRS one of the most frequently reported health conditions in Australia, comparable to asthma (9.9%). The prevalence was higher among females (11%) than males (8.9%), peaking among those aged 55–64 years1. Since 1995, the prevalence from the National Health Survey has not changed significantly from the rate of 10.1%6.Although CRS is often non-life threatening and self-limiting, it can result in hospitalisation. In 2007–08, chronic sinusitis was the principal diagnosis for 10,349 hospital separations, with an average length of stay of 1.3 days. Hospital separation rates for CRS increase with age before peaking at 55–59 years, after which the rate declines.

According to the survey of general practice activity, sinusitis (acute/chronic) was managed in 1.4% of general practice encounters in 2008–094, over half the rate of encounters for asthma. Of these sinusitis encounters, 0.9% were new problems and 0.5% were ongoing problems5. By extrapolating this data to the total MBS item numbers for the year, new encounters of acute and chronic sinusitis could account for over 1,000,000 encounters per year in general practice in Australia.CRS contributes to a significant healthcare expenditure due to direct costs arising from physician visits and medical treatment as well as indirect costs related to absence from work and general loss of productivity due to decreased quality of life of those affected7. CRS suffers have lower quality of life scores than patients with congestive heart failure, angina, chronic obstructive pulmonary disease or back pain7.

There has been an increasing focus on ongoing topical therapies to manage chronic airway inflammation. Our research has focused on the etiology of chronic rhinosinusitis1-4, the effects of nasal irrigation5, techniques to improve distribution6 and the basis for drug exposure7 for future novel topical drug solutions8,9.

The cornerstone of our research program is maintenance of the Rhinology Tissue Bank (SVH 10/187). We currently recruit all willing participants to offer tissue samples from their sinuses during surgery. This bank is a valuable store of respiratory mucosa, available for future study into chronic sino-nasal complaints and management of skull base tumours. We are fortunate to be at the forefront of research and therapies into CRS with much of our program involved in translational research, with direct clinical implications for current patients.

i) Epithelial dysfunction as an Inflammatory basis for CRS

The Rhinology and Skull Base program has a key focus on defining the role of epithelial mediated eosinophillic inflammation in CRS. The pathophysiology models of why patients develop chronic inflammatory disease in the sinuses, often well after bacteria have been removed, has changed dramatically in the past decade. The interaction between the innate and adaptive immune systems that maintain a homeostasis to our mucosal surface is a focus of our group. Epithelial derived cytokines (IL25 and IL 33) have been linked to underlying eosinphillia in CRS patients where the same is not true for TSLP, a mediator not exclusively produced from the epithelium. There is growing acknowledgement of presence of innate non-B, non-T immune cells that may possess the ability to develop into local tissue eosinophilia in inflammatory airway disease. The mechanism of activation of these cells is a focus for future work by our group.

ii) Novel topical therapies

Defining CRS subpopulations, or endotypes, that may benefit from specific novel topical therapies and avoid the need for multiple sinus surgeries has been very successful in recent years. The St. Vincent’s Pathology department, with Dr Peter Earls, has helped us to establish a unique reporting system that identifies these sub-groups. This system has been subsequently used in the USA and Canada. The novel delivery of topical steroid to the paranasal sinuses is a research focus. The increased distribution of anti-inflammatory agents to the sinuses has been associated with a dramatic increase in the clinical success of managing patients with chronic rhinosinusitis. Along with research into alternative or adjunct topical agents, such as antiobiotics, we are now able to offer patients a 93% success of controlling their condition with simple topical therapies and thus avoid systemic therapies or multiple surgeries10.

 2. Extended endoscopic skull base surgery

The skull base is at a crossroads: it is a meeting point for anatomical regions, surgical specialties, and surgical philosophies.  Skull base surgery is a dynamic subspecialty and the last decade has witnessed the application of endoscopic techniques to the ventral skull base using an endonasal corridor.   The transition from external approaches to an endonasal corridor has seen a significant decline in patient morbidity and inpatient care. Multidisciplinary collaborations in managing complex pathologies of the skull base have defined the nascent field of Neurorhinology. For lesions encompassing the ventral skull base and paranasal sinuses, this interaction with other specialities, notably otolaryngologists and neurosurgeons, has allowed procedures to be developed that offer significant advantages to treatment modalities from 25years ago. Our research has focused on the management of certain pathologies11,12, endoscopic access to various areas on the skull base13,14, reconstruction of the defect14,15 and improving the quality of life/function post treatment  

i) Evolving surgical methods and techniques

As technological advancements and novel surgical instruments were developed for use in inflammatory disorders, complex procedures have been performed endoscopically. The Rhinology and Skull Base unit has been at the forefront of advancements in the development of new surgical techniques to reconstruct the skull base15,16, access to difficult to reach anatomical sites14,17, adapting traditional surgical techniques to manage the type of pathologies18 now addressed endoscopically and ensuring that clear anatomical landmarks can be identified during the surgery13.

ii) Quality-of-Life and post-treatment function

St Vincent’s Hospital is fortunate to have a skilled skull base surgical team. Common endoscopic skull base tumour surgery at St Vincent’s includes meningioma, pituitary tumours, craniopharyngiomas and chordomas. Additionally, St Vincent’s Hospital provides endoscopic approaches to some vascular lesions and the latest management of nose and sinus tumours.  The focus of surgical treatment in these conditions is always to control disease and cure patients, however, we continue to make efforts to reduce the impact of our therapies. This focus is not just on reducing recovery time and perioperative morbidity but also on decreasing the long term impact of having a tumour removed. Retaining good nose and sinus function from the area in which the tumour was located is a secondary but critical endpoint.

Current projects include:

1. Mometasone irrigation in the treatment of chronic rhinosinusitis (RCT) (SVH 10/011)
2 .Eotaxin 3 single nucleotide polymorphisms in Chronic Rhinosinutis
3. Eotaxin 3 expression in CRS and its association to eosinophillia
4. IL25, IL33 and TSLP regulation in CRS
5. Staph Aureus resistance patterns in CRS
6. Lysine aspirin desensitization therapy for nasal polyps and chronic rhinosinusitis (SVH 10/092)
7. Mupirocin Lavage in the treatment of chronic rhinosinusitis (SVH 10/012)
8. Structured histopathological reporting in CRS
9. Cochrane Review: Topical or Systemic Antifungal Therapy for the Symptomatic Treatment of Chronic rhinosinusitis or Allergic Fungal Sinusitis19.
10. Outcome assessment of external septal reconstruction20
11. Quality of life in endoscopic skull base surgrical patients
12. Lateral frontal sinus access in endoscopic skull base surgery17
13. Efficacy of vidian neurectomy in the management of non-allergic rhinitis
14. Diagnostic Triptan treatment protocols for facial/non-sinus pain