75% of the world's conjoined twins are joined at the chest and abdomen, with connections at other parts being extremely rare.
For this pair of conjoined sisters, the situation where the base of the skull and cervical vertebrae are joined is even rarer; there's no report in the literature, making the challenge for Yang Ping apparent.
The scientific training has made Yang Ping not just a doctor who treats and performs surgery, but also a doctor capable of solving unknown problems, because he is a scientist among doctors, not simply a surgical craftsman.
In previous surgeries on conjoined twins, shared organs weren't truly shared but mixed-use between two sets of organs. For example, the stomachs are connected, and the surgery needs to separate the stomachs and repair the connecting tissues, as with other substantial organs. So-called sharing is due to interconnection through blood circulation or other pathways.
