MATERIALS AND METHODS: This is prospective controlled trial. Peripheral venous blood sample is obtained from 20 patients with AAA and 36 normal control subjects. MMP-9 concentration levels were determined by an enzyme-linked immunosorbent assay and compared with subjects abdominal ultrasonography or computed tomography of abdomen.
RESULTS: Mean (± SE) MMP-9 was 23.94 ± 0.60 ng/mL in normal control subjects and 21.39 ± 1.03 ng/mL in patients with AAAs (p ← 0.05 versus normal control subjects). MMP-9 correlate significantly with AAA (p=0.004). There was no correlation of MMP-9 levels with age, gender, or other risk factors. The cutoff point is 12.54 for aorta size <3.0 cm. The sensitivity and specificity of MMP-9 were 60% and 64% respectively.
CONCLUSIONS: MMP-9 levels correlate significantly with AAA with a cutoff point of 12.54. However, the utility of MMP-9 as a diagnostic test is limited due to low sensitivity and specificity. An elevated MMP-9 has limited use to predict the presence of AAA (positive predictive value: 60%) and a normal MMP-9 level was insufficient to determine the absence of AAA (negative predictive value: 36.1%).
PATIENT CONCERNS: A 73-year-old Asian gentleman with underlying hypertension, hyperlipidaemia, chronic renal failure, and history of chronic smoking presented to the emergency department with acute left lower limb swelling of 1 day. On examination, the patient was tachycardic (110 beats/minute) and hypertensive (168/84 millimeters mercury (mmHg)). The entire left lower limb was swollen with notable pitting oedema, tenderness, and warmth; left calf swelling was measured to be 4 centimeters (cm).
DIAGNOSES: The patient's Wells score of 4 placed him in the high-risk group for deep vein thrombosis. Serum D-dimer was subsequently found to be elevated at 926 nanograms/milliliter (ng/ml). Compression ultrasonography revealed a thrombus in the left deep femoral vein, confirming the diagnosis of deep vein thrombosis. The ultrasonographic evaluation was extended to the abdominal aorta due to the patient's high risk of abdominal aortic aneurysm, and a 7-cm aneurysm was indeed found. Further computed tomography and magnetic resonance imaging localized it to the infrarenal region, with left common iliac vein compression resulting in stagnant venous return.
INTERVENTIONS: Emergency endovascular repair was performed with insertion of an inferior vena cava filter.
OUTCOMES: The patient was subsequently monitored in the intensive care unit and uneventfully discharged after 2 weeks.
LESSONS: Such clinical presentations of deep vein thrombosis are rare, but physicians are reminded to consider screening for abdominal aneurysms and other anatomical causes before heparinization in patients who seemingly do not have thromboembolic risk factors. This is especially so for the high risk group of male deep vein thrombosis patients aged 65-75 years with a history of smoking who have yet to be screened for abdominal aortic aneurysms, in line with United States Preventive Services Task Force recommendations.