OBJECTIVE: To investigate the relation between placental embolisation and the diastolic notch in the uterine artery flow velocity waveform of pregnant ewes under general anaesthesia. METHODS: Seven pregnant ewes at a gestation 16 to 17 weeks were anaesthesized and microbeads of gelfoam were injected into the uterine artery; changes in the uterine circulation were assessed by Doppler velocimetry. RESULTS: Gelfoam embolisation reduced uterine blood flow in a dose-dependent manner, from a mean (95%, CI) of 568 mL/min (495-641) to 159 mL/min (131-187) after the injection of 30 mg of gelfoam, and increased the uterine vascular resistance from 135 mmHg x min x L(-1)(103-167) to 498 mmHg x min x L(-1) (422-574). A diastolic notch in uterine artery flow velocity waveform was observed after 20 mg to 25 mg of gelfoam in two ewes and after injection of 30 mg of gelfoam in all seven animals. Injection of 30 mg of gelfoam increased the pulsatility index to 2.4 (1.9-2.9) from 0.6 (0.5-0.7). The mean uterine vascular resistance at the time of the appearance of a diastolic notch was 414 mmHg x min x L(-1)(377-451). CONCLUSION: These findings suggest that an elevated pulsatility index and the presence of a diastolic notch in the uterine artery flow velocity waveform are indicators of increased uterine vascular resistance and impaired uterine circulation.
OBJECTIVE: To investigate the relation between placental embolisation and the diastolic notch in the uterine artery flow velocity waveform of pregnant ewes under general anaesthesia. METHODS: Seven pregnant ewes at a gestation 16 to 17 weeks were anaesthesized and microbeads of gelfoam were injected into the uterine artery; changes in the uterine circulation were assessed by Doppler velocimetry. RESULTS: Gelfoam embolisation reduced uterine blood flow in a dose-dependent manner, from a mean (95%, CI) of 568 mL/min (495-641) to 159 mL/min (131-187) after the injection of 30 mg of gelfoam, and increased the uterine vascular resistance from 135 mmHg x min x L(-1)(103-167) to 498 mmHg x min x L(-1) (422-574). A diastolic notch in uterine artery flow velocity waveform was observed after 20 mg to 25 mg of gelfoam in two ewes and after injection of 30 mg of gelfoam in all seven animals. Injection of 30 mg of gelfoam increased the pulsatility index to 2.4 (1.9-2.9) from 0.6 (0.5-0.7). The mean uterine vascular resistance at the time of the appearance of a diastolic notch was 414 mmHg x min x L(-1)(377-451). CONCLUSION: These findings suggest that an elevated pulsatility index and the presence of a diastolic notch in the uterine artery flow velocity waveform are indicators of increased uterine vascular resistance and impaired uterine circulation.
Authors: Jimmy Espinoza; Roberto Romero; Yeon Mee Kim; Juan Pedro Kusanovic; Sonia Hassan; Offer Erez; Francesca Gotsch; Nandor Gabor Than; Zoltan Papp; Chong Jai Kim Journal: J Perinat Med Date: 2006 Impact factor: 1.901
Authors: Jimmy Espinoza; Roberto Romero; Jyh Kae Nien; Ricardo Gomez; Juan Pedro Kusanovic; Luis F Gonçalves; Luis Medina; Sam Edwin; Sonia Hassan; Mario Carstens; Rogelio Gonzalez Journal: Am J Obstet Gynecol Date: 2007-04 Impact factor: 8.661