RESUMO
OBJECTIVE: To describe mesenteric and cerebral blood flow velocities after surgical patent ductus arteriosus (PDA) closure in premature infants. STUDY DESIGN: We measured middle cerebral artery (MCA), celiac artery (CA), and superior mesenteric artery (SMA) Doppler ultrasound scanning blood flow velocity (BFV) preoperatively, 3 and 24 hours after ligation. RESULTS: We studied 32 infants, with a mean (+/- SD) birthweight of 762 +/- 170 g and gestational age of 25.6 +/- 1.4 weeks at a mean age of 34 +/- 13 days. Significant changes in end-diastolic (EDV), average velocity (AV), and vascular resistance were measured in all 3 vessels by 3 hours. AV increased significantly in the CA and SMA within 3 hours; however, no significant increase in MCA AV was found until 24 hours after surgery. CONCLUSION: PDA ligation significantly changes BFV in the MCA, CA, and SMA. In the MCA vascular tone is acutely modulated, with no change in AV at 3 hours. In the CA and SMA, AV increases acutely after ligation. These different patterns of change in BFV suggest region-specific adaptation to surgical PDA closure.
