Leo, who has had 15 surgeries, now breathes through a tracheostomy, instead of his nose and mouth, and is fed via a small button in his tummy connected to a feeding tube.
The family are planning to move to Germany later in the year, which is Anja's homeland, where Leo will get help at a leading paediatric hospital near Hamburg.
Hopefully Leo's cyst problems can be rectified before the option of an airway construction was considered.
Tony said his son was developing well and the prognosis was good.
"He has made huge leaps in his development since he has been home - he's crawling, starting to make noises, is trying food, and is pretty healthy.
"He will learn to eat again, the tracheostomy will come out, but it's just about how long it takes."
Helping the family during the difficult times has been Ronald McDonald House.
Ronald McDonald House, in Wellington, Auckland and Christchurch, provides free accommodation and support for families with children in hospital, which reduces the financial, emotional and practical burdens that families face during a highly stressful time.
The family spent 11 months at Ronald McDonald House in Wellington and Auckland.
They're back home but need support from nurses overnight to monitor Leo because he can't vocalise and he needs to be suctioned.
Anja said Ronald McDonald House had been very important to them.
"I have no idea what we would have done without them.
"The staff have been friendly and very welcoming.
"It almost felt like home."
Tony said Ronald McDonald House had enabled the family to stay together.
"I don't think we could have done it without Ronald McDonald House."
And the family have had a Ronald McDonald retreat in Rotorua.
"That was our first family holiday and was something we wouldn't have been able to do without their help, because we needed a lot of equipment to take with us," he said.
This week is Ronald McDonald House Charities Appeal
People can donate $3 to Ronald McDonald House by texting 'FAMILY' to 4483 or by visiting www.rmhc.org.nz/donate.
There are also donation boxes in every McDonald's restaurant, ASB branch and Heritage hotel.
And a street collection will be held nationwide on Friday.