BikeNZ and High Performance Sport medical staff believed the problem related to narrowing in the main artery in her leg, a medical issue that is not uncommon with cyclists because of their riding position. The surgery last month was a success. BikeNZ high performance director Mark Elliott said Hanlen was back on her bike and on target for Glasgow.
"It's a real relief for Karen because she has had issues for the last couple of years and unable to pinpoint the reasons for her slow opening lap in races that would see her drift back through the field," Elliott said.
"She already feels the benefits and her training programme has her back on track for Glasgow.
"Even with this issue, her results in New Zealand and the world cup were sufficient to earn a nomination, which has been supported by the New Zealand Olympic Committee."
Hanlen plans to head to Europe next month for a lead-up race ahead of the Commonwealth Games. She joins fellow mountain bikers Anton Cooper, Sam Gaze and Fluker for the cross country race on Tuesday July 29.