By Stephanie Stahl

PHILADELPHIA (CBS) — Formerly conjoined twins are recovering after being separated at Children’s Hospital of Philadelphia. CHOP has done more surgeries to separate conjoined twins than any other hospital in the country.

They’re complicated, difficult operations that take months of planning.

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It was a special delivery at CHOP where Addy and Lilly Altobello were born on November 18, 2020. Maggie and Dom didn’t even know they were having twins until their first ultrasound.

“I thought, what is that? Is there two of them?” mom Maggie said.

Another surprise, the twins were conjoined.

“That’s OK, we’ll just separate them,” Maggie said.

That meant heading to CHOP, one of the few hospitals in the country that specializes in separating conjoined twins.

First was the delivery.

“They were just so tiny and so beautiful and rosy, and I just loved their little noises. I could hear noise from them,” Maggie said.

“The twins had separate hearts, completely separate, in that they were normal in their anatomy in terms of their hearts, and we knew the liver was joined. We knew their chest wall and body wall was joined, we knew that their diaphragms were joined,” the doctor said.

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Addy and Lilly spent 11 months in CHOPS NICU so they could be strong enough for the surgery that happened last October.

“We were crying with excitement and nervousness and love and just like you girls have no idea what is about to happen,” dad Dom said.

Once the surgeons had separated the girls, they had to move to another table and begin the reconstruction process. After the 10 hour surgery, seeing the girls separated for the first time was an emotional moment.

There were a couple more months recovering from surgery and just before Christmas, the entire Altobelli family returned home to Chicago.

“No matter what’s happening in the world, there’s a whole lot of good every single hour, every single day,” Dom said.

The girls still need assistance breathing, but doctors hope they’ll be off the ventilators soon.

CHOP is also about to open a new hospital in King of Prussia. CBS3’s Stephanie Stahl received a tour Friday.

The facility has 52 rooms and the first dedicated pediatric emergency department in the suburban Philadelphia area.

CHOP-KOP will offer a broad range of services including specialists in orthopedics and plastic surgery.

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The new CHOP location will officially open next Wednesday, Jan. 26.

Stephanie Stahl