Is it permissible to allocate most of the Zakat al-Mal (obligatory charity on wealth) to purchase surgical staplers for indigent patients, and to reduce the surgeon's fees, considering a portion of this reduction as Zakat al-Mal?

Reducing the cost of medical treatment with the intention of it being Zakāt is not permissible. This is because it is not permissible to account as Zakāt something that was not initially established as a debt owed by the poor person. Furthermore, the poor person must be given ownership of the Zakāt money so that they can dispose of it as they wish. However, purchasing staplers and giving them to the poor with the intention of Zakāt is permissible according to those who allow the disbursement of monetary value in Zakāt.