A common question that is asked from time to time is how does a hair follicle or graft grow after it is transplanted? This is a great question and an important one.
Follicle grafts are taken from the safe zones in men via Follicular Unit Extraction (FUE) or by the standard strip/Follicular Unit Transplant (FUT) method and are transplanted into the scalp where hair is needed which is also called the recipient area. Small slits are used to create the “sites” at which the follicle grafts will reside. The depth of the slit is within 1-2mm and usually sub-dermal. The follicle grafts are carefully “placed” into the scalp with fine instruments and orientated in a natural fashion designed by the hair transplant or hair restoration professional. Now what happens?
Follicle grafts are immediately cut from capillary circulation and thus the source of nutrients and oxygen are cut off during an FUT or FUE procedure.  For this reason alone it is critical to provide these follicle grafts a bridge until they can re-establish themselves another source of nutrients and oxygen, although some oxygen can be extracted from ambient air. The bridge/s until this occurs are in two different areas.
1. A holding or storage solution before they are transplanted.
2. The recipient area within the scalp.

  1. Physiological Saline or 0.9% NACL is the standard holding solution and is still used today in many hair transplant clinics. If the grafts are going to be stored for a relatively short period of time, then chilled saline (around 5 degrees Celsius) can be highly effective to keep follicle grafts from desiccation and not have osmotic instability such as in hypo-tonic or hyper-tonic environments. Follicle hair grafts can survive outside of the body up to 12 hours but they do have an exponential decrease in yield after 12 hours. In comparison to other transplanted organs and tissue:  The heart must be extracted, sewn back in and beating within 4 hours. The liver and pancreas must be transplanted within 2 to 14 hours after physiological death. The lungs must be transplanted 4 to 6 hours after a physiological death. Corneas, when preserved in specific media can last up to and over 14 days. So one can conceive that follicle hair grafts are very hardy outside of the scalp but time is of essence when the 12th hour approaches. The reason for a decreased yield is that these follicle grafts are alive with cells actively respiring. They are continually using the nutrients from their surroundings and while this is occuring, the waste by products from cellular respiration can decrease the Ph balance of Saline. A lower Ph can cause cellular damage. The absence of a continuous nutrient source can also cause these cells to go into what is called apoptosis (programmed cellular death).  Other issues that occur are associated with what are called “free radicals”. Free radicals are released during trauma such as the dissection of follicle grafts. Free radicals are also damaging to cells in follicle grafts.

Different medias are now employed today to combat Ph changes, nutrients, and free radical problems. Medias such as Plasmalyte A, Lactated Ringers, hypothermosol and balancing salts solution are used in lieu of physiological saline. All of these media are a great addition to hair restoration however not exactly necessary if the hair clinic is efficient in the extraction and and transplanting of the follicle grafts.
The next area of concern for follicle grafts is the recipient area in which they are transplanted. Below is an image showing the natural capillary circulation to each and every follicle in the human scalp.
Part II coming soon…
Thomas Ortiz
Surgical Technician