Lead Researchers:
Professor Ian Cook, Ms Julia Maclean, Mr Michal Szczesniak, Dr Ian Cole, Dr Michael Farrell
Significance
Although we take swallowing for granted (we do it subconsciously 1200 times each day!), when swallowing is dysfunctional, it can be lethal. The most common cause of swallow dysfunction is stroke. Around 50% of stroke patients have swallowing difficulties. If this is associated with aspiration, this leads to death in 45% of affected patients within 12 months. Head and neck or oesophageal cancer are also frequent causes of swallow dysfunction.
Major Achievements
The St George Hospital has multidisciplinary Swallow Clinic which has an established reputation in providing expert assessment, diagnosis and treatment of a range of complex swallowing disorders. The team includes professionals from the fields of Speech Pathology, Gastroenterology, ENT, Nutrition and Dietetics and basic science and physiology.
Mr Michal Szczesniak and Prof Ian Cook have defined the biomechanical defects in a range of disorders of the pharyngo-oesophageal segment including diseases such as Parkinson’s, inflammatory muscle disease, and stroke. They have developed innovative measurement techniques, which will improve the way in which we can assess the relationship between throat muscle contractions and flow during normal and disordered swallowing. This work has had an impact on indicators of outcome following treatment and aids in treatment selection for specific patients.
This work has highlighted the need for systematic evaluation of pharyngeal biomechanics before and after laryngectomy in order to design consistent and appropriate reconstructive techniques to achieve a better functional swallow post-operatively and thereby reduce morbidity in these patients.
Ms Julia MacLean in the Department of Speech Pathology discovered that swallowing difficulties are far more prevalent following total laryngectomy than the traditionally believed figures of 16-50%. They showed that 70% of laryngectomy patients have significant swallowing difficulties with over a quarter being unable to eat out socially because of the problem. In auditing surgical techniques, she has found marked variability among Australian head and neck surgeons in pharyngeal reconstruction techniques following total laryngectomy. This work has highlighted the need for systematic evaluation of pharyngeal biomechanics before and after head and neck surgery in order to design consistent and appropriate reconstructive techniques to achieve a better functional swallow post-operatively and thereby reduce morbidity in these patients.
Current and Future Research
Mr Michal Szczesniak and Prof Ian Cook are conducting studies, which are elucidating the mechanisms of oesophageal dysfunction during swallowing and in chest pain syndromes where traditional endoscopic and radiographic studies do not yield a diagnosis. They are pioneering the application of novel measurement techniques (eg combined manometry, intraluminal impedance) in defining the importance of various types of poorly understood oesophageal contractions to the transport of food through the oesophagus.
Ms Julia MacLean is measuring swallowing instrumentally (using a combination of video, radiography and pressure recordings) laryngectomy patients in order to define the biomechanical consequences of different reconstructive techniques as well as the functional consequences of concurrent radiotherapy and chemotherapy in head and neck cancer patients. It is hoped that this important research will lead to improvements in reconstructive techniques and to improved clinical outcome.
Recent publications
Williams RB, Wallace KL, Ali GN, Cook IJ. Biomechanics of failed deglutitive upper esophageal sphincter relaxation in patients with neurogenic dysphagia. Am J Physiol 2002;283:G16-G26.
Williams RB, Grehan MJ, Hersch M, Andre J, Cook IJ. Biomechanics, diagnosis, and treatment outcome of inflammatory myopathy presenting as oropharyngeal dysphagia. Gut 2003;52(4):471-478.
Szczesniak MM, Rommel N, Dinning P, Fuentealba S, Cook I, Omari T. Optimal criteria for detecting bolus passage across the pharyngo-oesophageal segment during the normal swallow using intraluminal impedance recording. Neurogastroenterol Mot. 2008: In Press.
Maclean J, Cotton S and Perry A. Variation in surgical methods used for total laryngectomy in Australia. Journal Laryngology and Otology, 2008 (In press)
Chen CL, Szczesniak MM, Cook IJ. Identification of impaired oesophageal bolus transit and clearance by secondary peristalsis in patients with non-obstructive dysphagia. Neurogastroenterol Motility 2008; In Press.
