Table 3 Challenges and resolutions associated with surgery

• Initial intubation resulted in high CO₂ pressure

• Nasal intubation via right nostril also resulted in high CO₂ pressure

• Paediatric and adult anaesthetists with experience in MPS disorders present

• Intubation via left nostril successful

• Patient’s short neck made central line insertion difficult

• Ultrasound-guided central line insertion by paediatric anaesthetist

• Pericardial adhesions from previous mitral valve replacement surgery at the age of 24 years

• MPS-associated valvular pathology

• Adhesions removed

• Fibrous tissue, calcification and GAGs removed from mitral valve

• Physically small patient

• Paediatric catheters used to remove excess blood from ventricles

• Smallest adult replacement valve used (size 19 mm CarboMedics Top Hat® mechanical prosthesis)

• Tracheostomy required because of narrow trachea, but difficult for paediatric and adult anaesthetists to perform

• ENT surgeon assisted

• Pre-surgery 3D CT of chest and trachea, and fluoroscopy results were used to identify optimal site

• No cardiology expertise in hospital performing surgery^a

• Medical files provided by the treating doctor

• Surgeons discussed surgery with treating doctor to understand MPS-specific requirements

• Patient and family did not wish ERT to be interrupted by surgery^a

• ERT infusions arranged to occur during recovery at hospital performing surgery

• Patient had a short stature and restricted respiratory function^b

• Neurosurgeon had extensive experience in paediatric patients

• High cardiovascular risk

• Pre-surgery cardiac and respiratory function tests

• Risk that patient may not tolerate procedure or epithelium may be pierced

• Make preparations in case general anaesthesia is required

• Risk of graft rejection

• Endothelium preserved, resulting in reduced risk