Stagnation of portal blood flow

Thrombosis is often secondary to: ① portal vein congestion and portal vein blood flow stagnation caused by cirrhosis or extrahepatic compression; ② purulent infections in the abdominal cavity, such as gangrenous appendicitis, ulcerative colitis, strangulated hernia, etc. Some blood abnormalities, such as true erythrocytosis, hypercoagulability caused by oral contraceptives; ④ injuries caused by trauma or surgery, such as mesenteric hematoma, splenectomy, right colonectomy and so on. About a quarter of patients have no obvious cause and are called primary mesenteric venous thrombosis. Venous thrombosis can continue to spread proximally and distally. When the venous return of the affected bowel is completely obstructed, the intestinal canal is congested and edema, and the blood under the serosa is spotted first, and then spreads into pieces. Intestinal wall and mesentery thickened and edema. Following this, intestinal flexure developed a hemorrhagic infarction, which was dark purple. A large amount of bloody fluid leaks from the intestinal wall and mesentery to the intestinal cavity and abdominal cavity. Acute venous occlusion can still cause reflexes of visceral arteries and thrombosis, and accelerate the process of intestinal necrosis. Finally, it also leads to hypovolemia and toxic shock.