We usually approach and execute the revision hair transplant in the following manner:
Number one is to counsel the patient for a realistic expectation and chances of success & failure. In many cases, the implanted grafts have grown, but the patient expected a surgically impossible density. We carefully evaluate the results of patients to make a fair assessment of post-operative results. And there are many reasons the results may not show up, i.e., smoking, no proper care after the hair transplant, not following the instructions.
In many cases, a revision may be the solution. But we recommend our patients to wait for 12-18 months, and if there are no expected results, you may need a professional assessment for revision surgery.