SONOGRAPHIC AND DOPPLER ASSESSMENT OF THE INFERIOR MESENTERIC-ARTERY - NORMAL MORPHOLOGIC AND HEMODYNAMIC FEATURES

Background: We wanted to evaluate prospectively the feasibility of son ographic and Doppler assessment of the inferior mesenteric artery (IMA ) and to provide data on its normal morphological and hemodynamic char acteristics. Methods: Sonography and Doppler study of the IMA were per formed on 116 patients without splanchnic vessel pathology. Vessel dia meter, systolic, diastolic, and time-averaged mean flow velocities, pu lsatility index values, and flow volumes were correlated with patient age (< 50 years vs. greater than or equal to 50 years) using the Wilco xon rank-sum test. Findings were verified by splanchnic angiography in 11 cases. Results: Technically valid studies were obtained in 103/116 cases (88.8%). Flowmetric data showed high peripheral resistance (mea n +/- SD: systolic flow velocity, 1.41 m/s +/- 0.48; minimal diastolic flow velocity, 0.10 m/s +/- 0.16; pulsatility index, 3.49 +/- 0.49). Mean flow volume calculated in 80 cases was 0.13 L/min +/- 0.06. Older subjects presented significantly higher time-averaged mean flow veloc ities and lower resistance than those younger than 50 years. Conclusio ns: The success rate for sonographic and Doppler study of the IMA is s imilar to that observed with larger splanchnic vessels. Knowledge of i ts normal characteristics is necessary for recognition of pathological conditions and for studies of its physiological behavior.