-centesis

A puncture or perforation of a body cavity.

Greek kentēsis, pricking.

This forms medical terms that relate to making a puncture in order to remove fluid or gas for diagnostic or therapeutic purposes. Examples are amniocentesis (Greek amnion, caul), a process in which amniotic fluid is sampled using a hollow needle inserted into the uterus, to screen for abnormalities in the developing fetus; paracentesis (Greek para, beside), the perforation of a body cavity, especially with a hollow needle to remove fluid or gas; and pericardiocentesis, removal of excess fluid from within the pericardium, the sac surrounding the heart.