Bariatric surgery is conventionally not considered as treatment for hypothalamic obesity syndromes. A female with Prader-Willi syndrome (PWS) due to a micro-deletion on chromosome 15p was first seen by the paediatricians at age 20, and weighed 146kg. Central and obstructive sleep apnoea was treated with CPAP and oxygen. Orlistat was commenced in 2000, followed by apronectomy in February 2003. In April 2003 she weighed 114.2kg.

She was first seen at the Royal Adelaide Hospital in February 2004 aged 31, and weighed 120.8kg (BMI 35.5kg/m²). Orlistat had been discontinued. She lived independently with support from her mother and travelled by bus and train each day to supported work. In July 2004 at 129.4kg Sibutramine 10mg daily was commenced, and December 2004 weight was 120.5kg. During admission for cholecystectomy to another hospital, Sibutramine was stopped and Risperidone commenced. In May 2005 she was 134kg. Previous therapy was restored and weight decreased to 121.9kg in March 2006 but 3 months later was 130.5kg, type 2 diabetes mellitus had developed and metformin was commenced. In September 2006 at 127.2kg, Sibutramine dose was increased to 20mg. Her weight gradually decreased to 106kg by March 2011 when Sibutramine was discontinued following worldwide withdrawal. By July 2012 her weight increased to 116kg and HbA1c from 6.7 to 7.3%. CPAP was changed to BiPAP. She underwent an open Roux-en-Y gastric bypass (RYGB) with a 20mL pouch in May 2013 at a weight of 109.7kg. Recovery was uneventful. At 7 weeks post-op she weighed 98kg. HbA1c was 5.8% on no metformin. There was marked decrease in leg swelling, improved mobility, general well-being and control over food intake.

Prior reports^1-3 of 4 adults (2 LSG, 2 RYGB) and 1 child (LSG) with PWS show excellent results at 1 to 2 years, and a national trial seems warranted.