PALO ALTO, California—Stanford surgeons have successfully separated conjoined twins Angelica and Angelina Sabuco on Tuesday afternoon, after eight hours of surgery. “The surgeons are happy with the progress of the operation so far,” said Lucile Packard Children’s Hospital spokesman Reena Mukamal.

The two-year-old sisters were moved into separate operating rooms for reconstructive surgery by 3 p.m. PDT, the first time in their brief lives they have ever been apart. Without the procedure, the San Jose, California, twins—fused at their liver—would have faced a troubled future, with curved spines, muscle problems and the emotional challenges of intimately shared lives.

But the rare procedure posed the threat of massive bleeding or the catastrophic introduction of an air bubble into the venous system, causing heart attack or stroke.

A team of 20 doctors and nurses participated in the delicate procedure, which is performed about six times a year in the United States.

The girls have separate hearts, which made surgery feasible. In addition, their digestive systems function independently. And although their sternums were joined, their ribs are separate. But their livers were tightly fused together. This worried doctors, due to the risk of blood loss or embolism.

Pediatric surgeon Gary Hartman first incised the girls’ skin and muscle; plastic surgeon Peter Lorenz cut through their rib bones. Then the girls’ diaphragms and livers were divided. Finally, Hartman cut any adhesions between the girls’ bowels, as well as any last bit of shared skin.

Reconstructive surgery is needed to rebuild the girls’ chest and abdominal walls. Afterward, the girls will be in intensive care, where they’ll recover for four to five days before being moved to a regular room for another week or so. Then they’ll head home to San Jose to start their lives as two ordinary little girls. (MCT-San Jose Mercury News)

In Photo: Conjoined twins Angelina and Angelica Sabuco sit with their aunt Marita Sabuco before undergoing separation surgery on Tuesday, in Stanford, California. Angelica and Angelina are classified as thoraco-omphalopagus, joined at the chest and abdomen. Their livers, diaphragms, breastbones, chest and abdominal wall muscles are fused. They have separate hearts, brains, kidneys, stomachs and intestines. (AP)