A spokesman for the Heart of England NHS Foundation Trust has said that an external review of breast surgery at Solihull Hospital found that Mr Paterson was not following new guidelines.
In a statement, he said:
[A 2007 internal] review ... identified that a surgical technique for mastectomies used by one of its consultants, Mr Ian Paterson, required closer scrutiny to establish whether it represented best practice.
An external review highlighted that this was not a usual procedure and that Mr Paterson had not followed guidelines to introduce a new technique.
This trust's position, after careful consideration, was that the technique was not an approach considered appropriate going forward, and the method was therefore stopped.
An NHS helpline has been set up for patients of the breast cancer surgeon Ian Paterson who is being investigated for possible misconduct.
Dr Aresh Anwar, medical director for Solihull Hospital, said: "We have invited all of Mr Paterson's patients who underwent a mastectomy to see an alternative surgeon for a review of their treatment and care.
"We are keen to hear from any patient who may have concerns or further questions and have set up a helpline to ensure that these can be addressed quickly."
The Heart of England NHS Foundation Trust advice line can be contacted on 0121 424 5473 between 9am and midday, Monday to Friday.
Thompsons Solicitors have also set up a helpline for women who may be affected on 08000 224 224.
Thompsons Solicitors, which is pursuing negligence claims for several women, made the following claims about breast surgeon Ian Paterson.
Mr Paterson allegedly performed invasive breast surgery on 450 women when a biopsy might have been sufficient.
A General Medical Council investigation into Mr Paterson potentially spans up to 700 cases of an unregulated procedure that involved leaving some breast tissue behind after a mastectomy.
The solicitors said the breast surgeon worked at numerous NHS and private hospitals from 1994 - including those run by Heart of England NHS Foundation Trust - which covers hospitals in Sutton Coldfield, Solihull and Birmingham.