Thrombosis of the superior mesenteric vein

Mesenteric venous thrombosis is a disorder in which local blood clotting interferes with venous return of blood to the intestines. Intestinal venous thrombosis is common in the superior mesenteric vein. Although mesenteric vein thrombosis is a relatively rare condition, mortality remains high due to nonspecific symptoms, delayed diagnosis, and inadequate clinician awareness of this pathology. .

1.1 Definition Mesenteric vein thrombosis is a disease that occurs due to a decrease in the return of the mesenteric veins in the intestine due to local coagulation. Primary mesenteric vein thrombosis is considered idiopathic, while secondary mesenteric vein thrombosis is the result of intestinal or systemic diseases. This pathology can lead to mesenteric ischemia and accounts for 5 to 15% of the causes of this complication.
There are three veins that carry blood from the intestine to the portal venous return:
The superior mesenteric vein. The inferior mesenteric vein. Splenic vein. Mesenteric vein thrombosis almost always involves the small intestine (superior mesenteric venous drainage) and rarely the colon (lower mesenteric venous drainage). In other words, superior mesenteric vein thrombosis occurs more often than inferior mesenteric vein thrombosis.
1.2. Venous thromboembolism is primarily the result of blood flow stagnation, vascular damage, and hypercoagulability (Virchow's triangle).
Acute thromboembolism of one or more mesenteric veins reduces perfusion pressure due to increased mesenteric vein resistance. When blood flow is stalled, venous pressure increases resulting in increased blood flow into the tissues, causing edema of the intestinal wall, which can lead to submucosal hemorrhage. If the accessory venous arches, rectal veins, and other veins returning from the intestinal wall are completely obstructed, intestinal infarction will occur.
The deposition of fluid in the intestinal lumen combined with edema of the large bowel wall leads to a decrease in relative volume and systemic hypotension. As a result, arterial flow is also reduced, exacerbating ischemia. Arterial spasm is another factor thought to be important in the pathogenesis of ischemia and infarction associated with mesenteric vein thrombosis. Under experimental conditions, arterial spasm can occur in the presence of venous occlusion.
The anatomical site associated with acute mesenteric vein thrombosis is usually the ileum (64-83%) or the jejunum (50-81%), followed by the colon (14%) and the duodenum. 4 - 8%).
Distribution of inferior mesenteric veins is less common for reasons that are not well understood but may be related to accessory flow through the internal iliac system, rectal venous plexus, or systemic circulation through the venous system. left renal vein, splenic vein, and mesenteric vein, although this has not been proven. Meanwhile, the superior mesenteric vein has less accessory flow, so when there is a blood clot in this vein, the phenomenon of superior mesenteric ischemia is more likely to occur.

Local inflammatory processes in the abdomen such as pancreatitis, inflammatory bowel disease or trauma such as splenectomy increase the risk of mesenteric vein thrombosis.
Inherited thrombophilia such as Protein C or Protein S deficiency, Antithrombin III deficiency, Factor V Leiden mutation, Prothrombin gene mutation, sickle cell disease. Acquired thrombosis is seen in hematologic diseases such as polycythemia vera, myelofibrosis, myeloproliferative disease, monoclonal gammopathy, JAK2 mutation, antiphospholipid antibodies, paroxysmal nocturnal hemoglobinuria , disseminated intravascular coagulation , thrombocytopenia due to Heparin... Acquired thrombocythemia in nephrotic syndrome , malignancies , hormone replacement therapy , hormonal contraceptive use , Hyperhomocysteinemia , women pregnant or postpartum women. Other conditions such as cirrhosis, portal hypertension, congenital venous malformation, heart failure, splenomegaly.

3.1. History There are no clinical features specific to superior mesenteric vein thrombosis and all forms of mesenteric ischemia. Therefore, the patient's personal and family history should be carefully considered. A personal or family history of deep vein thrombosis or pulmonary embolism is present in approximately half of patients with acute superior mesenteric vein thrombosis.
3.2. Clinical symptoms The clinical features of superior mesenteric vein thrombosis are determined by the location and time of thrombus formation, divided into acute, subacute and chronic
3.2.1. Acute phase Some authors suggest that the definition of acute mesenteric vein thrombosis should be limited to symptomatic duration of less than 4 weeks. Symptoms resemble acute mesenteric ischemia, suggested by the onset of episodic abdominal pain that persists for at least several hours. The onset is less abrupt, the pain is often a dull ache that may be accompanied by fever. Abdominal examination revealed abdominal distension, without abdominal wall or peritoneal reaction. Hidden blood may be found in the stool. Abdominal distention, inaudible bowel sounds occur as ischemia is increasing. In the later stages, there may be abdominal wall or peritoneal reactions. 3.2.2. Subacute phase The subacute form of superior mesenteric vein thrombosis occurs in cases where the venous occlusion is sufficient to produce ischemia but is sufficiently compensated through the accessory vessels to permit recovery. Symptoms are often very poor. Non-specific abdominal pain, dull pain around the navel, vague abdominal pain. 3.2.3. Chronic stage Often asymptomatic and discovered incidentally through imaging tools. Common symptoms include intermittent pain after eating. Venous bleeding or ascites due to portal hypertension. 3.3. Subclinical Computed tomography (CT-scan) with or without oral contrast. Magnetic resonance imaging (MRI). In doubtful cases, CT-scan of blood vessels or MRI of blood vessels is recommended. In addition to more accurately differentiating the arterial and venous forms of acute mesenteric ischemia, catheter-based angiography provides access to targeted therapies. thrombosis and other interventions. 3.4. Differential diagnosis Other causes of abdominal pain Lactic acidosis Intestinal infections Hypovolemic shock Gallstones Volvulus of the stomach Helicobacter pylori infection Large bowel obstruction Myocardial infarction Kidney stones Septic shock

The goals of treatment for superior mesenteric venous thrombosis are to prevent the expansion of thrombus and intestinal infarction in the short term and to prevent the recurrence of the thrombus in the long term.
4.1. Medical treatment Give the patient rest. Nasal aspiration, gastric aspiration for patients with abdominal distension, intestinal obstruction and intractable nausea or vomiting. Intravenous infusion. Abdominal pain control. Broad-spectrum antibiotics are used in patients with thrombophlebitis or mesenteric thrombophlebitis and in patients with bacterial superinfection translocated from intestinal infarction. Red blood cell transfusion in gastrointestinal bleeding. Anticoagulation: Unfractionated Heparin should be used immediately at diagnosis, the advantage of using unfractionated Heparin is that it is safe in the presence of renal failure and when invasive procedures are planned. Low molecular weight heparin is eliminated by the kidneys with a half-life of 6 to 12 hours and cannot be used in the presence of renal impairment. When the patient's condition improved and invasive procedures were not required, switch to Warfarin therapy. The duration of anticoagulation is approximately 6 months for patients who respond to the drug. Thrombolysis: Catheter fibrinolysis may be considered in patients with severe acute mesenteric vein thrombosis who have not responded to anticoagulation. Contraindications to catheter fibrinolysis include history of stroke or intracranial hemorrhage, primary or metastatic CNS malignancy, history of or ongoing bleeding, history of recent surgery, previous history of recent trauma and mesenteric infarction. 4.2. Surgical treatment Interventional radiological options are considered for patients at risk for intestinal infarction but without peritonitis.
Thrombectomy: Catheter-assisted thrombectomy can be considered as an adjunct to fibrinolysis and anticoagulation, especially in cases of large vessel thrombosis. Options include percutaneous mechanical thrombectomy, angioplasty and stenting, and thrombectomy. Intestinal resection: Indicated in cases of mesenteric vein thrombosis leading to hemodynamic instability, peritonitis and intestinal infarction. Surgical procedures include laparotomy or laparoscopy. Recurrence of mesenteric vein thrombosis after bowel resection is as high as 60%, with the majority of recurrences at the intestinal anastomosis site Mesenteric thrombosis in general and superior mesenteric vein thrombosis in particular is a The disease is rare, so the diagnosis and treatment is quite complicated and not widely available. Therefore, when detecting any of the above abnormal symptoms, patients should immediately go to the nearest medical facility for examination and treatment by specialized doctors.
Vinmec International General Hospital is a prestigious health examination address with a team of highly qualified doctors, modern equipment and machinery. Therefore, when there are any health problems, patients can go to Vinmec to be checked as soon as possible.