Objective: Endoscopic images of the colonic mucosal venous structure in eight cirrhotic patients with esophageal varices and in eight noncirrhotic subjects were analyzed to qualitatively determine whether or not the vasculature be altered by persisting portal hypertension.
Methods: On the endoscopic images, a venous network consisting of confluent venous branches draining into one penetrating vein was as a whole defined as one "venous unit." For each venous unit, the area of vein bed was calculated by means of an image processor. Each venous network was idealized to be a graphic representation consisting of lines (venous routes) and dots (origins, terminations, branching or anastomosing), on which two topological variables, the total number of zero-dimensional cells (a0) and the Betti number of dimension-1 (beta 1[K]), signifying the complexity and the number of venous anastomoses, respectively, were determined.
Results: The area of vein bed (mean +/- SD) was significantly greater (p < 0.01) for the cirrhotic patients (41 +/- 37 mm2) than for the noncirrhotic subjects (24 +/- 12 mm2). The a0 was also greater (p < 0.01) for the patients (68 +/- 29) than for the noncirrhotic subjects (42 +/- 17). The beta 1[K] for the patients was significantly greater (p < 0.01) for the cirrhotic subjects (7.1 +/- 4.4) than for the noncirrhotic subjects (2.6 +/- 2.9).
Conclusion: The image processing and topological analysis of the colonic mucosal veins demonstrated that persistent portal hypertension alters the colonic mucosal venous structure by increasing the caliber of the veins and the number of merges (branching or anastomosing) between them.