Surgery

Measures directed against microorganisms on living tissue, distinct from merely covering a wound or deodorising a discharge.

A hollow tube introduced into the body; a historical tapping instrument leaves it in place after the trocar is withdrawn.

A pointed instrument used with a surrounding cannula to enter a fluid-containing cavity.

Withdrawal of fluid from the peritoneum with a needle or catheter, for diagnosis or relief of ascites.

A penetrating instrument and associated tube used historically to enter and drain a cavity. Its historical use does not establish safety for modern ovarian-mass management.

A vascular cushion of the anal canal; symptomatic bleeding, enlargement or prolapse constitutes haemorrhoidal disease.

Protrusion through an aperture within the abdominal cavity, rather than through its external wall.

A lateral anterior-wall hernia, including the defect through the semilunar region lateral to the rectus sheath.

Displacement of a hernia and its sac while a constriction remains, so apparent disappearance of the external swelling need not mean safe reduction.

A hernia trapping only part of the bowel wall; severe vascular compromise may occur without complete obstruction of the lumen.

A crack is an internal separation surface, or a curve in a two-dimensional reduction, across which a displacement can have distinct traces. In the ideal traction-free model its two faces carry zero imposed traction. A crack tip or front terminates this separation and can produce a singular stress field. The stress intensity factor measures the leading singular amplitude, while the energy release rate measures the reduction in equilibrium potential energy per increment of crack extent.