Jane Grocott, 66, was injured when a medical device moved during the procedure at Birmingham's Queen Elizabeth Hospital, causing blood vessel damage.
Hospital chiefs have apologised to the grandmother of three, of Rowley Park, Stafford, who was left with severe memory problems and reduced speech. She is now registered blind, uses a wheelchair and cannot feed herself.
The trust said the housewife's treatment had fallen "significantly below expectations," that equipment had been replaced and lessons learned as a result.
In a letter to her husband Chris, the trust's chief executive Professor David Rosser stated: “I am very sorry that Jane did not receive the level of care that she was entitled to expect from the trust and that we aim to provide to all our patients.
“I would like to offer the trust’s sincere apology and regret that there was a failure to treat Jane appropriately and we are sorry that this resulted in Jane suffering a serious brain injury which has had such as significant effect on both of you.”
Mrs Grocott was initially referred to a specialist after attending an opticians complaining of reduced vision. This led to surgery being carried out on October 11, 2018. The following day a scan showed she had suffered a stroke.
She spent two months in hospital before being discharged to a rehabilitation unit where she stayed for four months before returning home.
Mr Grocott , a retired dentist, said: “Before Jane’s stroke we really enjoyed life as a family and were looking forward to our retirement. She used to be such a fun and outgoing person. She could strike up a conversation with anyone and I used to say ‘Jane could talk for England’.
“Sadly, that’s all in the past for us now, and seeing my wife struggle day after day is heartbreaking. Jane used to be independent and looked after all of us but now she needs everyone else to help care for her.
“Jane has very poor short-term memory and little to no spontaneous speech. She will answer questions but cannot strike up a conversation, which is so different to how she used to be.
“It’s difficult not to get upset at how our lives, but particularly Jane’s, have changed forever because of the failings in her care.
“However, as a family we also don’t want to try and dwell on the past. The admission by the trust means we can now focus on getting Jane the best care possible, allowing her the best quality of life she can have.
“We just hope that by speaking out we can help raise awareness of the impact a stroke can have and try and prevent what happened to Jane from happening to others.”
University Hospitals Birmingham NHS Foundation Trust said a full investigation into the case had taken place, lessons had been learned and actions implemented.
A spokesman added: “We would like to once again offer our sincere apologies to Jane and her family. The treatment that she received whilst in our care fell significantly below everyone’s expectations.
Medical negligence lawyer Emma Rush, of Irwin Mitchell, said: “The catastrophic and avoidable injuries Jane suffered have had a devastating effect, not only on her but her family.
“The last few years and trying to come to terms with how life has changed has been incredibly difficult.
“While nothing can make up for what’s happened we’re pleased that we have been able to provide the family with the answers they deserve.
“We welcome the trust’s apology and continue to work with it to ensure Jane receives the specialist support, care and therapies she will require for the rest of her life.
“However, it’s also vital that lessons are learned from what happened to improve patient safety.”