In 1976, Richard Selzer wrote Mortal Lessons: Notes on the Art of Surgery as a dramatic account of his early life and love of anatomy that led him to become a successful surgeon. The book is partially a factual account of his experiences, and partially a poetic look at the feelings and emotions of surgery, which can be a traumatic experience for both surgeon and patient.
One enters the body in surgery, as in love, as though one were an exile returning at last to his hearth, daring uncharted darkness in order to return home.
It is the stillest place that ever was... when the blood sluices fierce as Niagara, when the brain teems with electricity, and the numberless cells exchange their goods in ceaseless commerce -- why is it so quiet? Has some priest in charge of these rites utters the command "Silence"? ... Soon you shall know surgery as a Mass served with Body and Blood, wherein disease is assailed as though it were sin.
(Selzer, Mortal Sins, Google Books)
The comparison to Catholic Mass is apt because of the allegory for the Communion taken as "blood and flesh of Christ." The pilgrim returns to the love of God at the Mass from darkness, fleeing the sin outside and met with love and forgiveness; the surgeon returns to the body to purge the sin of disease, giving the body kindness through his work. Additionally, while many surgeries are performed with music to relax the surgeon (similar to musical hymns), many others are performed in silence so as not to break concentration.
In short, while the Mass is meant to cleanse and heal the soul from its sins and iniquities through metaphorical blood and flesh, the surgery is meant to heal the body of its disease through literal blood and flesh.