About our team

Advance Surgical Team Perth

bariatric surgeon jon armstrong

Mr Jon Armstrong

General Surgeon


Mr Armstrong is a UK and Australian trained Bariatric, General and Endocrine Surgeon and is the founder and director of Advance Surgical, Nedlands est. 2013.
Obtaining his fellowship of the Royal Australasian College of Surgeons in 2002.
Mr Armstrong has performed over 3000 bariatric procedures and over 2500 sleeve gastrectomies.
He has published results from his series and has presented these results at several international meetings. Mr Armstrong also performs Endocrine Surgery and General Surgery (except Breast and Colorectal surgery).

Mr Armstrong has worked as a consultant surgeon since 2002 and operates at
St. John of God Hospital Subiaco and
Hollywood Private Hospital.

Patient consultation sessions at
- Hollywood Medical Centre, Nedlands.
- St John of God, Carine Specialist Centre.
- Rockingham Specialist Centre.

Dr Jon Armstrong is a fellow and member of the following :

  • Royal Australasian College of Surgeons (FRACS)
  • International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO)
  • Obesity Surgery Society of Australia and New Zealand (OSSANZ)
  • International Association of Endocrine Surgeons (IAES) International Surgical Society (ISS)
  • Australian and New Zealand Endocrine Surgeons (ANZES)
  • West Australian Endocrine Surgeons (WAES)
Bill Gong bariatric surgeon

Mr Bill Gong

General Surgeon


Bill is a specialist General Surgeon. He completed his training at The Alfred Hospital in Melbourne and obtained his Fellowship with the Royal Australasian College of Surgeons in 2014.

Dr Gong moved to Perth to pursue Fellowship opportunities at Fremantle and Fiona Stanley Hospital. Bill and his family love the beautiful outdoor lifestyle of Perth and decided to call it home.

Bill trained in minimally invasive laparoscopic bariatric surgery as well as gall bladder surgery and complex abdominal wall hernia surgery. Dr Gong also works as a surgeon endoscopist performing both upper and lower endoscopies. He has a special interest in bariatric related endoscopies and also endoscopy as a treatment for reflux disease.

Bill Gong bariatric surgeon

Mr Siva Sundararajan

General Surgeon


Siva obtained his qualifications as a General and Bariatric Surgeon in Australia. Born in India and then migrating to Singapore, where he served in the Singapore Army as a medic for several years. Following on from the Army Services, Siva attended the University of Edinburgh to study Medicine. Surgical training as a specialist General Surgeon was commenced in Scotland before then migrating to Perth. General surgical training was completed in Western Australia and Siva was selected for the Bariatric Fellowship at Box Hill Hospital, Melbourne.

Further training was also attained in Bruges, Belgium, and then returning to Australia as a:

-Specialist Bariatric (weight loss) and General Surgeon,
-Military surgeon in the RAAF.

Main areas of interest are:
- Advanced laparoscopic surgery for weight loss
- Acid reflux and hernias
- Endoscopy and
- Educational assistance to both medical students and training surgeons.

Siva is highly experienced in all types of weight loss surgery including
- gastric bypass
- sleeve gastrectomy and
- all bariatric revision surgery.

Accredited in both public and private hospitals in Perth.

Dr Sarah Harris

GP Bariatric Assessor


Studied medicine at the University of Western Australia – graduating in 1993.

Gaining registration and  Fellowship with the Royal Australian College of General Practitioners in 1998.

Has worked as a bariatric physician and  also as an assistant surgeon for the past 15 years in both general and bariatric surgery.  The duel experience of bariatric physician and assistant surgeon in bariatric surgery has given Dr Harris an encompassing understanding of all aspects of the patient’s weight loss journey.

Witnessing the benefits, both medical and emotional, that follow a patient’s weight loss makes her job extremely rewarding.

Dr Harris is available for all follow-up care post bariatric surgery. Patients that have not had surgery due to a low BMI can also benefit from consultations to discuss options available to them besides surgery.


Practice Manager - Dip Applied Science (Diagnostic Radiography)

Nadia assisted in the start up of Advance Surgical in 2013 and has been an integral part of the Advance Surgical team since.

Qualified as a Medical Imaging Technologist 2003 (specialising in MRI), this previous background of working in the medical field has given her the ability to align easily into the role of Practice Management.

Nadia is involved in the smooth running of the practice and assisting in clinics, arranging theatre lists/bookings and helping with superannuation applications.  She is able to provide you with information on any consultation with Advance Surgical and looking forward to being of assistance to you.

Sarah Flanagan


BSC, Grad Dip (Dietetics), MDAA, APD, AN

Sarah Flanagan divides her time between her private practice and being a mother of two busy children. Born and raised in Perth, Sarah went on to study Dietetics at Curtin University before working in the Goldfields and South East Coastal region of WA. It was there that she met her husband David and decided to travel and work overseas. Sarah gained a broad range of dietetic experience working as a Dietitian overseas (London, Guernsey and Ghana).

Then returning to Western Australia, working at a number of Perth hospitals before taking on the role of Public Health Dietitian at The National Heart Foundation of Australia where she worked for over 2 years.

In 2004 and after having her 2 children, Sarah started her own private practice. For over 10 years, Sarah has been working predominantly in the field of bariatric (weight loss) surgery. In addition to this, Sarah provides on-going mentorship for Dietitians and has worked with Edith Cowan University as a Clinical Supervisor. Sarah is a Patron for the Charity, Kalparrin, and devotes a lot of her spare time promoting the importance of supporting families of children with special needs and disabilities.

Anne Marie Stanley


BSc, Grad Dip (Dietetics), APD, AN

Anne Marie has been a Dietitian for 23 years since graduating from Curtin University. She has been dedicated to private practice throughout most of these years however; she also has experience working in public and private hospitals, with Diabetes WA and on community based projects. Anne Marie has a special interest in aged care having worked in both restorative and residential care settings.

She has extensive experience as a Dietitian consulting with individuals undergoing Bariatric surgery, being one of the first dietitians in Perth to undertake this role. She has been a keen advocate of the multidisciplinary approach to weight management surgery and has also been involved in research related to the effectiveness, long term outcomes and health impact of these surgeries.

Anne Marie recently returned to Perth after living in Singapore for a few years with her family. She enjoyed sharing the cultural experience of living in a foreign country with her children and is grateful to have been able to contribute some of her time there as a volunteer for Habitat for Humanity and Ronald McDonald House. Supporting families with critically ill children at Ronald McDonald House and working side by side with families to build their first homes in Malaysia and Indonesia, are experiences she will remember forever. Volunteering has become a passion that she and her family now share and have continued since arriving back in Australia.

Margaret Hays


Bsc (Nutrition), Grad Dip (Dietetics), Grad Dip (Diabetes Education)

Margaret has been a Dietitian for 28 years and currently works in Private Practice seeing clients one on one in Corporate Health. Margaret also works in Indigenous remote communities with Chronic Disease Specialist Teams and has worked as both a Community Nutritionist and a Dietitian in the Food Industry both here and overseas.

Preventative Health is one of Margaret’s passions, so working with clients to lower their risk of Chronic Disease is a high priority for her. She also works with people that already have Diabates, Heart Disease, Weight Issues and other Health Conditions to improve their health through better food and nutrition choices. She is able to help clients make lasting changes to their food and lifestyle habits in a manner that is helpful, supportive, practical and friendly.

As a Senior Media Spokesperson for the Dietitians Association of Australia, Margaret is often called upon to provide both Diet and Nutrition related comments for National TV, Newspaper and Radio.

Melanie Greenfeld

Melanie Greenfeld

Specialist Psychologist


Melanie is a Specialist Psychologist who has spent many years specializing to help overweight and obese adults lose weight, and maintain their weight losses. For many years her focus has been on the care and support of bariatric surgery patients, helping them achieve the behavioural, psychological and lifestyle changes necessary to ensure the best possible weight loss and quality of life outcomes from surgery.

Overweight and obesity are complex conditions, resulting from a combination of biological, psychological and social factors unique to the individual. Successful treatment involves understanding how these factors have combined to cause problems for each individual.

Melanie is committed to providing outstanding care matched to the specific needs of her clients, within a supportive, respectful environment.

Shirley Armstrong

Shirley Armstrong


Shirley has worked in the medical sector for over 15 years.
She is exceedingly competent and knowledgeable, and she can help you with all aspects of our practice.  She is responsible for overseeing the services provided to you from your initial telephone enquiry, until you are discharged from the care of your Surgeon.

She is extremely compassionate and an asset to our team.

Shirley Armstrong

Kirstie Potter


Kirstie has worked in the medical sector for many years.
She is knowledgeable in all aspects of Bariatric and General surgery, and can assist you with everything from initial consultation, bookings for procedures and then all follow up required.  She is a great part of the team at Advance Surgical.


DEXA scan for Body Composition

Dexa Body Composition Scan.

Modern technology has made it possible to safely “see inside” a person’s body. A DEXA body composition scan can be a useful tool when diagnosing and treating:

Obesity and weight management
Body fitness ( as the scanner can calculate your metabolic rate)
Osteoporosis ( the scanner will calculate your bone density). A DEXA body composition scan allows you to see exactly where you are before weight loss surgery and then allows you to monitor your progress as you lose weight. Your DEXA body composition scan can answer questions like:

Are you losing or gaining muscle?
Is there a reduction in the central/visceral fat?

It also allows you to see your bone density and calculate your lean muscle mass and metabolic rate. These differences in X-Ray absorption are used to determine bone mineral density (BMD) and body composition values

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Contact Advance Surgical


Hollywood Medical Centre Suite 8, 85 Monash Avenue Nedlands WA 6009 (Perth)


+61 8 9386 2634


+61 8 9386 2167


Monday - Friday: 9am - 5pm