Vaginas have been grown in laboratories and implanted in human patients for the first time.
Four teenage girls received vaginal organs that had been grown with their own cells in a laboratory at the Wake Forest Baptist Medical Centre's Institute for Regenerative Medicine, North Carolina.
Published in the Lancet, all four women were born with a rare genetic condition where the vagina and uterus are underdeveloped or missing. The condition, Mayer-Rokitansky-Küster-Hauser syndrome, affects around one in 5,000 girls.
Research leader Anthony Atala said: "This pilot study is the first to demonstrate that vaginal organs can be constructed in the lab and used successfully in humans.
The women were between 13 and 18 years old at the time of their surgeries, which were performed between 2005 and 2008. Eight years on, the findings show the organs had retained normal function."This may represent a new option for patients who require vaginal reconstructive surgeries. In addition, this study is one more example of how regenerative medicine strategies can be applied to a variety of tissues and organs."
The women also filled out a Female Sexual Function Index questionnaire showing they had normal sexual function, including pain-free intercourse and desire.
Atlantida-Raya Rivera, lead author of the paper, said: "Tissue biopsies, MRI scans and internal exams using magnification all showed that the engineered vaginas were similar in makeup and function to native tissue."
How were the vaginas grown?
Researchers engineered the vaginas using muscle and epithelial cells, which line the body's cavities, from each patient's external genitals. The cells were then extracted and expanded before being placed on a biodegradable material that had been hand sewn into a vagina-like shape tailor-made to fit each patient.
Six weeks after the biopsy, surgeons created a canal in each of the women's pelvis and sutured the scaffold to the reproductive structures. Once implanted, the nerves and blood vessels form and the cells expand to form tissue. The scaffolding material is absorbed by the body and the cells form a permanent support structure to replace it.
Tests showed the difference between native tissue and the lab grown vaginas was indistinguishable, while the scaffold had developed into vaginal tissue.
Breakthrough treatment for MRHK
At present, treatment for MRHK includes reconstructive surgery using a variety of materials, including skin grafts and tissue that lines the abdominal cavity. These often lack normal muscle layer, however, and patients can end up with a narrowing or contracting of the vagina.
Complication rate for these treatments is high, with three in four women experiencing problems.
Researchers say that their treatment could also be applied to patients with vaginal cancer of injuries. However, they said that it is important to gain further clinical experience, as the current research is based on such a small sample.
Hope for the future
A comment piece in the Lancet discussing the study said: "Of course, progression from first-in-human experiences is in only a few patients, such as those reported by Raya-Rivera and Fulco and their colleagues to a full integration into health systems involves many steps, and is often an uphill struggle.
"There is a need for larger trials, with efficacy shown in larger patient cohorts with long-term follow-up; meanwhile, clinical grade processing, scale-out and commercialisation all incur substantial time and cost. However, these barriers are not unique to tissue engineering, and many countries now have large translational income streams, engaged biotech companies and streamlined regulatory processes that might lower these barriers."
What is Mayer-Rokitansky-Küster-Hauser?
MRKH is a disorder that affects around one in every 5,000 girls. It mainly affects the reproductive system, causing the vagina and uterus to be underdeveloped or absent. Women who have MRKH normally do not have periods because of their missing uterus.
The first noticeable sign of MRKH is when menstruation has not started by the age of 16. They have normally functioning ovaries and female external genitalia. Their breasts also develop normally. Women with the syndrome cannot normally have children naturally, but it is possible with assisted reproduction.
The cause of MRKH is unknown, although researchers believe it is likely a combination of genetic and environmental factors.