# Closed-loop obstruction

Closed-loop obstruction

This occurs when the bowel is obstructed at both the proximal and distal points ( Figure 78.2 ). The distension is principally confined to the closed loop; distension proximal to the obstructed segment is not typically marked. A classic form of  closed-loop obstruction is seen in the presence of  a malignant stricture of  the colon with a compe tent ileocaecal valve (present in up to one-third of  individuals). This can occur with lesions as far distally as the rectum. The inability of  the distended colon to decompress itself  into the small bo wel results in an increase in luminal pressure, which is August Gottlieb Richter , 1742–1812, lecturer in surgery , Göttingen, Germany , described this form of  hernia in 1777. Jacob Benignus Winslow , 1669–1760, Professor of  Anatomy , Physic and Surgery , Paris, France. greatest at the caecum, with subsequent impairment of  blood flow in the wall. Unrelieved, this results in necrosis and perfo - ration ( Figure 78.3 ). 

(a)
(b)
Figure 78.2
Distension. Closed-loop obstruction around a constrict
-
ing band (arrow) with impending strangulation, mild distension of the
proximal limb
(a)
and collapse of the distal limb
(b)
of small bowel.