Nearly a year after poachers in South Africa hacked off her horn and left her for dead, six-year-old rhino "Hope" has undergone a groundbreaking procedure to close the wound on her face. 

The surgery, which involves a crank-and-pulley system designed to help the gaping injury heal, was performed by wildlife vet Dr Johan Marais and his colleagues at the University of Pretoria's Department of Veterinary Sciences.

This is the same system used on abdominal injuries in human patients, where the walls of a wound are slowly stretched together to encourage cell regeneration. Developed in Canada, it's designed to help repair large injuries where skin and tissue have been lost.

To date, only ten rhinos have received this kind of operation, which took the team nearly two years to develop. Hope's case was made particularly challenging because poachers removed a portion of her upper jaw along with her horn. The young rhino was found critically wounded in a game reserve in South Africa's Eastern Cape in May last year. 

"Hope’s poachers were not professionals," says Marias. "Poachers normally know exactly where a rhino’s horn ends and the upper jaw begins, but these poachers thought the more they cut, the more horn they’d get." Marais is founder of non-profit group Saving the Survivors, which was established to treat rhinos and other endangered wildlife that have been victims of gunshot wounds, snaring and facial mutilation.

Her latest reconstructive surgery may not be Hope's last, and this resilient survivor has already endured five major operations to restore her face. 

“Hope still has a long road to travel, and it will take about a year before she is completely recovered," adds Marias. "If we can reduce the wound by 1 cm now, it will already be progress.” Initially a staggering "one metre by half a metre" in size, the gash now needs to close enough to allow the team to cover what's left of it with a collagen matrix, which will allow Hope's own cells to grow together the rest of the way. 

Hope is fit to breed, but she has been noticeably shy and cautious around other rhinos over the past year. While some concerned members of the public have asked whether it might be more humane to put her down, Marias is optimistic that Hope can recover.

"She's moving around, she's feisty – so I think we're doing the right thing here. Hope is a real ambassador for [the fight against] rhino poaching."