Flight Sergeant Tony Rohan knows more than most about the importance of blood donations.

The long-term donor said he wasn’t sure if the 45 times he had put his arm out to give blood played a “karmic role”, but it was donated blood that kept him alive during recent open-heart surgery.

Flight Sergeant Tony Rohan’s heart was stopped for three hour during the lifesaving surgery in which his aorta - the largest artery of the human body - was replaced with a Dacron tube.

“During a check-up, it was discovered that I had a dilation on my aorta which could have ruptured and killed me at any time without warning,” Flight Sergeant Rohan said.

“It was blind luck the doctors found the aorta dilation during an unrelated scan.

“Initially, the risk of rupture was low and doctors kept an eye on the dilation until it was time to act, at which point the major surgery was undertaken.

“I was placed on a heart-lung machine that kept me alive while my heart was stopped.

“Donated blood products maintained the right volume of blood in my body.

“I cannot say if my past blood donations played a karmic role, but I feel very lucky, with those 45 donations squaring the ledger."

Flight Sergeant Rohan has been giving blood since 1990, the year after he enlisted in the Air Force to pursue a radio technician apprenticeship after finishing Year 12 at high school in Adelaide.

“I remember my first blood donation was at Radio School at RAAF Base Laverton in 1990 after I’d turned 18,” he said.

“I was posted to No. 492 Squadron and the section would knock off to give blood when the bus to RAAF Base Edinburgh came, so I joined in and quickly gained a sense of gratification to be able to give back to the community."

His donations have helped children.

“In late 2003, I was posted back to Laverton and had an extreme bout of chicken pox," he said.

“Once I recovered, I was put on an accelerated program of blood donations for 12 months as my chicken pox antibodies were in urgent demand in Victorian children’s hospitals to help patients with leukaemia and immune deficiencies."

While he is recovering from his open-heart surgery, Flight Sergeant Rohan said he hoped to continue to donate  blood.

“Once my heart heals and I get the tick from the doc, I look forward to donating again,” he said.

During his career, he has primarily worked on AP-3C Orions, but also had opportunities to work on F/A-18A/B Hornet and PC-9 aircraft.

He currently works in the Air Warfare Engineering Squadron as an avionic systems technician.

Blood supplies are critical to Defence personnel on operations, exercises and to all members of the Defence community in their daily life.

The 2020 Defence Blood Challenge began on September 1 and will run until December 8.