Surgery to Separate Twins Continues

Neurosurgeons performing a marathon operation to separate Iranian sisters joined at the head grappled today with rerouting a vein as thick as a finger that helps blood flow through their brains.

The operation on 29-year-old Ladan and Laleh Bijani was entering a crucial phase, said a spokesman for Singapore’s Raffles Hospital. The surgery is expected to last two to four days.

Surgeons planned to begin separating the twins’ brains later today after encountering an unexpected delay in cutting through the skulls when the bone turned out to be denser than anticipated, Dr. Prem Kumar said. “There are some twists and turns that we will have to navigate. The twins are taking to the procedure quite well.”