answer:After a quick review, the Y method does not appear to be the “only” method, just the most frequently used. The body is propped up underneath the back, creating an arch. The Y method apparently prevents any liquids still in a fluid form from seeping out unexpectedly that still may appear in the chest cavity. The skin can be pulled back conveniently from that initial cut, allowing access to the whole rib cage, and later sewn back together. Awesome question btw.