Acute mesenteric ischemia (AMI) results when oxygen delivery to the mesenteric artery is compromised, and is a serious diagnosis that should be considered in patients of all ages to avoid significant morbidity and mortality. The majority of cases are due to arterial embolism, arterial thrombus, or intestinal hypoperfusion (non-occlusive). Acute mesenteric venous thrombosis (MVT) accounts for only 2% to 10% of AMI cases, and only 0.01% of emergency surgery admissions.1 A large systematic review showed a 44% mortality rate for MVT, in contrast to 66% to 89% for all other forms of AMI.2 The typical age range for MVT is reported between 45 and 60 years, with a slight male predominance.3 Dull, central abdominal pain is the most frequently reported symptom of MVT, although it is generally less impressive than the pain described in other forms of AMI.3Along with the hallmark of abdominal pain out of proportion to the examination, other gastrointestinal symptoms include weight loss and non-specific altered bowel function (constipation, diarrhea, abdominal distention, and bloating), which are present in half of all patients with MVT.1 Peritoneal signs and bloody stools portend poor outcomes, as they often occur with disease progression.4
Case
A 26-year-old man presented to the ED with periumbilical and lower abdominal pain for 1 week. The pain was described as constant and dull, worsened by movement and oral intake, and improved with lying flat. He described bloating and decreased volume of bowel movements. He denied nausea, vomiting, fever, colicky pain, blood in stool, testicular pain, urinary complaints, trauma, or any similar episodes in the past. The patient had no known medical conditions or surgical history, except for a remote history of alcohol dependence (in remission) and tobacco use. There was no personal or family history of coagulopathy. Of note, he was seen by his primary care physician a few days prior to his ED presentation and had been instructed to take acetaminophen, which did not provide relief.
The patient’s vital signs at presentation were: blood pressure, 122/70 mm Hg; heart rate, 93 beats/min; respiratory rate, 18 breaths/min; and temperature, 37.5°C (99.5°F). Oxygen saturation was 99% on room air. The physical examination was remarkable only for mild abdominal tenderness diffusely, greater in the lower and central abdomen than in the upper abdomen. The remainder of the physical examination was unremarkable.
Laboratory studies ordered included a complete blood count, comprehensive metabolic profile, lipase, and urinalysis. The patient did have a mild transaminitis (aspartate aminotransferase, 48 U/L; alanine aminotransferase, 84 U/L); the remainder of the studies were normal. A serum lactate, drawn after the 1 L of normal saline was administered intravenously (IV), was within normal limits (0.7 mmol/L). No prior laboratory studies were available for comparison.
The patient’s continued abdominal pain and transaminitis prompted an ED bedside right upper quadrant ultrasound, which showed a small gallbladder polyp; no signs of gallbladder disease were present. The patient required three doses of morphine 4 mg IV without complete pain relief. Given the concern for pain out of proportion to physical examination, a computed tomography (CT) scan of the abdomen/pelvis with IV and oral contrast was ordered. The radiologist interpreted the scan as showing a superior mesenteric vein (SMV) thrombus extending into the splenic/portal vein confluence and the intrahepatic portal veins (Figures 1 and 2).
Figure 1.
Figure 2.
Ciprofloxacin and metronidazole were administered IV for antibiotic prophylaxis, and the patient was placed on bowel rest with advancement to regular diet as tolerated. Propranolol was given for variceal prophylaxis. The patient was discharged home the following day in stable condition. Although he still had mild abdominal tenderness, the vital signs and physical examination were within normal limits. The patient was placed on a 6-month course of rivaroxaban therapy. Coagulopathy testing was scheduled at a later date, since ongoing anticoagulation treatment could interfere with test results. Unfortunately, the patient did not attend follow-up appointments to obtain testing.