Hair Falling off 4 Years After Hair Transplantation (FUE) Procedure

Dear 34male
Thanks for the question. If necessary, hair transplant can be repeated 3-4 times depending on the density and the number of the hair follicles on the donor site.
A second hair transplant can be planned in cases of continuing rapid hair loss, with patients who desire a high density of hair, for the purpose of providing a hairy scalp on those sites where no prior transplantation has been done, and for the purpose of correcting the outcome with those patients who have had an unsuccessful hair transplant in some other clinic. I wish you all the best.

Hair loss after transplantation can occur for a variety of reasons.  First of all, hair loss which was harvested from the proper location can ultimately be lost.  For this reason, proper surgical planning can be helpful to only harvest hairs which will not be susceptible to androgenic alopecia.  In addition, some patients may have other factors to their hair which can contribute to hair loss which need to be properly evaluated.  Hair loss is a complex medical and surgical problem which requires specialized attention to achieve appropriate results.

We have been performing hair transplants now for over 20 years. It would be my opinion that this is very unusual.
I would suggest going back to the MD that treated you and let them examine.
I would want to see what your hairs look like under magnification. If I see miniaturization, I would begin treating with Laser to kick start the hairs back to the growth phase.