We define a follicular unit as a naturally occurring group of hair follicles, typically containing between one and four hairs. These are the grafts extracted during a hair transplant and later implanted into the recipient area. However, this process is not performed one graft at a time. Instead, hundreds of follicular units are first harvested and then implanted. During the period in which they remain outside the body, proper follicle preservation is essential.
A follicular unit remains viable thanks to the continuous supply of oxygen and nutrients delivered through the blood vessels in the scalp. Hair loss occurs when susceptible follicles progressively lose this support, causing the hair to miniaturize and eventually stop growing. During a hair transplant, once a living follicle has been removed from the scalp, it must be maintained under optimal conditions to preserve its viability and maximize its survival after implantation.
At Instituto Médico del Prado, we use premium preservation solutions specifically designed to protect living tissue. These are similar to the solutions used to preserve organs such as the heart, liver, pancreas, and kidneys prior to transplantation. By maintaining the follicular units under these optimal conditions, survival rates can approach 100%.
Other factors involved in follicle preservation
The preservation solution is only one of several factors that influence graft survival. Hair transplantation is a highly precise medical procedure in which every stage plays an important role in achieving the best possible outcome. At Instituto Médico del Prado, every procedure follows a strict quality protocol.
Dr. Espinosa Custodio personally performs both the extraction and implantation phases using state-of-the-art surgical instruments. One of his priorities is ensuring that the clinic always uses the most advanced medical technology available. This helps achieve precise graft extraction and implantation while minimizing trauma to both the donor and recipient areas.
Every member of the medical team at Instituto Médico del Prado has been trained according to Dr. Espinosa Custodio’s surgical protocols. His methods focus on maximizing graft survival through meticulous technique, efficient workflow, and careful handling of every follicular unit. During each procedure, he is assisted by experienced technicians specialized in hair transplantation.
In addition, Dr. Espinosa Custodio generally limits each surgical session to approximately 1,500 follicular units per day, except in carefully selected cases. As a result, most procedures are carried out over at least two consecutive days. This approach reduces fatigue-related errors, allows every graft to be implanted with maximum precision, and contributes to consistently high survival rates.
Frequently Asked Questions
What quality standards does Dr. Espinosa Custodio follow?
Hair transplants performed at the Madrid clinic fully comply with all healthcare regulations established by the Community of Madrid, in addition to the strict internal quality standards established by Dr. Espinosa Custodio himself. These protocols further enhance patient safety and help maximize the chances of a successful outcome. The doctor also offers a guarantee on his hair transplant procedures.
How long do the follicles remain outside the body?
Time is a critical factor during hair transplantation. From the moment a follicular unit is extracted until it is implanted, it undergoes a period known as ischemia, during which its viability gradually declines. For this reason, follicles should remain outside the body for as little time as possible. Dr. Espinosa Custodio alternates extraction and implantation throughout the procedure to minimize out-of-body time and maximize graft survival.
Is time outside the body the only factor that can damage a follicle?
No. Follicular units can be affected at several stages of the procedure. The experience and skill of both the surgeon and the assisting technicians are essential in minimizing these risks. Every step—including extraction, handling, preservation, and implantation—must be performed with exceptional care to avoid damaging the follicle, as trauma can compromise its survival and long-term growth.
Dr. Espinosa Custodio works at Instituto Médico del Prado, his hair clinic in Madrid, and performs hair transplants in Mexico, twice a year. If you would like to make an appointment, you can contact us on +34 912 468 664, on WhatsApp +34 627 396 322 or on the contact page of our website. From Mexico you can contact us at +52 55 4590 9909.


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