Researchers announced Tuesday the successful integration of laboratory-grown urinary bladders into patients, signalling a breakthrough in a field beset with hardship and controversy.

According to a report released by the British journal The Lancet, scientists from Wake Forest University School of Medicine and Harvard Medical School used cell samples of a patient’s bladder to re-grow the full-sized organ before surgically inserting it above the old one.

“This is one small step in our ability to go forward in replacing damaged tissues and organs,” said Anthony Atala, director of the Institute for Regenerative Medicine at WFUSM and lead researcher, in a press release.

While other simpler tissues, such as skin and bone cells, have been lab-grown, this marks the first time that a complex organ such as the bladder has been successfully grown and accepted by a patient.

In the past, similar transplants were done using tissue samples from other organs or through organ donors. Building a bladder from other tissue has often resulted in numerous complications, including rejection of the organ, bone loss, and even cancer.

Scientists believe that the widespread use of lab-grown organs may ease the massive shortage of requests for organ transplants, which currently stands at nearly 92,000, according to the United Network for Organ Sharing. Organ requests outpace donations by nearly a two to one margin.

In the study, seven children, aged 4 to 19, born with spina bifida, a spinal defect resulting in excessive bladder pressure and possible kidney damage, were involved in the study. Four years ago, they became the world’s first patients to receive laboratory-grown organs, and have been closely monitored by researchers to ensure the organs were accepted by the body. While the results were not perfect, the procedure has changed the patients’ lives.

“They’re more socially acceptable,” said Alan B. Retik, senior author and chief of urology at Children’s Hospital, in a press release. “I think ultimately it would be a boon for them—both their social and their work lives.”

Before surgery, patients often had to wear diapers and suffered from incontinence.

“Now that I’ve had my transplant, my body actually does what I want it to,” said 16-year-old Kaitlyn McNamara to US News Today, one of recipients of a new bladder. “It kind of boosted my self-esteem.”

Atala said that as this technique matures and becomes more mainstream, other organs such as hearts, livers, kidneys, pancreases can be laboratory-grown.

“This suggests that tissue engineering may one day be a solution to the shortage of donor organs in this country for those needing transplants,” said Atala in the press release.