Mesenterialvene

The mesenterial veins, or venae mesentericae, are a group of arteries in the mesentery that drain blood from the intestines and deliver it to the hepatic portal venous system. The two principal vessels are the superior mesenteric vein and the inferior mesenteric vein.

The superior mesenteric vein collects blood from the midgut, including the small intestine (jejunum and ileum), the cecum, and parts of the colon (ascending and proximal transverse colon). Its tributaries include intestinal veins, ileocolic veins, right colic veins, and middle colic veins. The inferior mesenteric vein drains the hindgut, including the left colon, sigmoid colon, and upper rectum, via left colic, sigmoid, and superior rectal veins. In most individuals, the superior mesenteric vein and the splenic vein join behind the neck of the pancreas to form the portal vein, which then transports nutrient-rich blood to the liver. In some anatomical variants, the inferior mesenteric vein drains into the splenic vein or directly into the portal system.

Clinical significance: mesenteric venous thrombosis is a serious condition that can obstruct venous outflow from the intestine, potentially causing mesenteric ischemia and abdominal pain. Risk factors include hypercoagulable states, pancreatitis, inflammatory bowel disease, and abdominal surgery. Diagnosis commonly employs contrast-enhanced CT angiography or MR venography, with Doppler ultrasound as an adjunct. Treatment centers on anticoagulation, with escalation to thrombolysis or surgical intervention in severe cases. Knowledge of mesenteric venous anatomy is important in abdominal surgery, radiology, and the assessment of portal hypertension.