"There was a good portion of the last few weeks that I was asleep, as those around me worked tirelessly to keep me alive," he wrote in a tweet he sent today.
"Mel put together a few shots to catch me up and we added a couple from the last two weeks as I've started the rehab process."
During life-saving emergency heart surgery in Sydney, Cairns suffered a stroke in his spine, resulting in paralysis in his legs.
Cairns' family said last month that he would undertake a significant rehabilitation process at a specialist spinal hospital, and the former all-rounder previously posted a video on social media to update fans on his condition.
"Just over six weeks ago I suffered a type A aortic dissection, which essentially means there's a tear in one of the major arteries of the heart," Cairns said. "I had several surgeries and grafts and, very thankfully, the specialists were able to save the heart itself.
Cairns thanked fans for the "uplifting, humble and special" messages he had been sent in the past six weeks and paid particular tribute to those who had treated him.
The former cricketer said he would continue to post and keep fans updated on the rigorous journey he was about to begin.
He has been living and working in Canberra with his wife Melanie and their children for several years.
Cairns had to rebuild his life after walking out of Southwark Crown Court in London in 2015 after being found not guilty of perjury and perverting the course of justice charges in relation to match-fixing allegations.
