Evaluation of Lower Extremities' Vascular Characteristics in Myelomeningocele Patients: A Case-Control Study

Myelomeningocele (MMC) is the most common neural tube defect. Patients with MMC have multiple risk factors for venous thrombosis, but this complication rarely occurs. This lower rate of venous thrombosis in MMC children could be related to some characteristics of the vessels in the lower extremities. This study aimed at finding explanations for this dilemma.

A case-control study was designed in the Children's Hospital Medical Center, Tehran considering paraplegic patients with MMC as the case group and nonparaplegic MMC patients as a control group. Doppler ultrasound was performed to evaluate femoral and popliteal arterial and venous properties.

Patients aged from 8 months to 12 years were evaluated. The mean diameter of the femoral arteries was 3.73 ± 0.23 and 4.72 ± 0.39 mm among paraplegic and nonparaplegic MMC patients, respectively (p = 0.02). The femoral artery flow was 0.52 ± 0.08 and 0.75 ± 0.06 L/min, respectively in the case and control groups (p = 0.015). The diameters of the femoral veins were 4.85 ± 0.34 and 5.13 ± 0.32 mm in the case and control groups, respectively (p > 0.05). Besides, the blood flows of the case and control groups' femoral veins were 0.27 ± 0.08 and 0.14 ± 0.01 L/min, respectively (p = 0.6). It turned out that lower extremities' arteries in the case group had significantly lower blood flow and diameter compared to those of the control group. However, the same venous properties did not show any significant differences.

The decreased arterial flow along with the unchanged venous properties leads to less stasis and better drainage of the blood, which in turn might result in a lower incidence of deep vein thrombosis.