A 26-hour operation has successfully separated conjoined twins at the age of 10 months old in Houston.

Elysse Mata gave birth last year at only 31 weeks pregnant to twin girls she named Knatalye Hope and Adeline Faith Mata. They were joined at the chest and the abdomen, according to a CBS News report.

A team of doctors at Texas Children’s Hospital spent 26 hours in surgery attempting to separate the girls, a difficult surgery for doctors as they had to be separated from the chest wall, lungs, lining of hte heart, the diaphragm, liver, intestines, colon, and pelvis, according to the report.

The girls shared several organ systems, making it a delicate procedure that took months for the team to prepare for. The team worked with radiology experts to construct a 3D model of the organs and conducted simulations of the actual surgery, according to Dr. Darrell Cass, a pediatric surgeon who serves as co-director of Texas Children’s Fetal Center.

Doctors were able to separate the twins after 18 hours, but it required a little extra work after that, with doctors working on Knatalye for 23 hours and Adeline for 26 hours. It required specialists in pediatric surgery, plastic surgery, liver transplant surgery, and a host of other practices to perform the separation.

The children will receive care in the Pediatric Intensive Care Unit for their months-long recovery, and they are likely to have additional surgeries in the future with no release date schedule.

Mata said she was “grateful” to everyone who worked on her daughters.