Esophageal collagen content and mechanical strength after endoscopic sclerotherapy of esophageal varices. An experimental study in rabbits.

Twenty-five rabbits with esophageal varices were randomized to no treatment (n = 10) or endoscopic paravenous sclerotherapy of the varices (n = 15). Five other rabbits served as sham-operated controls. When they were killed, the mechanical strength and collagen content of the esophagus were determined at proximal, middle, and distal levels. The esophagus was examined histologically at proximal and distal levels. Animals treated by sclerotherapy showed histologic edema and inflammation of the esophageal wall after 2 days. This was not accompanied by any decrease in collagen content or mechanical strength. Ten days after sclerotherapy a slight but non-significant increase in collagen content and mechanical strength at middle and distal levels was observed. After 30 days the increase in collagen content at middle and distal levels was significant, and the mechanical strength was significantly increased at the middle level.