A graft is a generic term for any piece of hair-bearing tissue that is transplanted into the scalp. Whether it is a modern follicular unit, a mini-micro, or one of the large 4-millimeter “plugs” of yesteryear, they are all technically considered grafts. Grafts can be harvested from all over the body, but they are usually selected from the occipital scalp (the back of scalp known as the donor zone) due to the hair’s high levels of sustainability in that region. Their overall size and shape are determined by the technology, tools, and surgical approach.
In general, hair grafts are created by removing tissue from the donor zone. The ultimate goal is to remove a small amount of tissue that can grow hair and transplant it to the area of the scalp that needs to grow hair (recipient scalp). Hair-bearing tissue from the donor zone can be removed either in a fleshy strip all out once (known as follicular unit strip surgery, or FUSS), or by removing the follicular units directly from the donor zone one at a time (known as follicular unit extraction, or FUE).
With FUSS (sometime incorrectly referenced as “FUT”), grafts are harvested from the donor strip. After the strip is removed from the occipital scalp, the physician’s team must dissect the follicular units from the donor strip using stereoscopic dissecting microscopes. These follicular units are then preserved and prepared for insertion into the recipient scalp as individual hair grafts. A follicular unit typically yields 2-3 hairs, though this is not universal. Next, the physician makes incisions on the recipient scalp that are the exact same size as the graft (called recipient sites). The grafts are then inserted one by one into each recipient site at the appropriate depth and angle with the goal or replicating nature.
With FUE, the physician does not need to remove a donor strip. Instead, the follicular units are individually extracted directly from the recipient scalp itself. These follicular units are then preserved and transplanted into the scalp in the same fashion as FUSS.
It is crucial that as many of the hair grafts survive the transplant from their original area into the recipient scalp as possible. Unfortunately, a number of factors can go awry:
The average follicular unit is considered to have 2 to 4 hairs, but some clinics will further divide follicular units into even smaller grafts with even fewer hairs. This step allows for an additional layer of refinement during the procedure, but also artificially inflates the graft numbers. Always ask your hair physician for a hair count evaluation before your surgery and compare this to your hair counts that are documented after your surgery.