Vascular resistance Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2009;31(9):427-432
DOI 10.1590/S0100-72032009000900002
PURPOSE: to evaluate the repercussion of portal hypertension in the indexes of the ovarian, uterine and luteus body periphery arterial resistance, at the medium luteal phase of the menstrual cycle. METHODS: in an observational study with transversal cohort, 28 patients with hepatosplenic schistosomiasis mansoni, submitted to splenectomy and ligation of the left gastric vein (HESO), a similar group of 28 patients who had not had the surgery (HESNO) and 29 healthy volunteers (HV) were submitted to Doppler fluxmetry in the medium luteal phase of the menstrual cycle. Pourcelot's resistance index has been used as RI=[(S-D)/S], in which S means the highest systolic speed, and D, the end of diastole. The best record in the ascendant branch of the uterine artery, in the ovarian artery, when accessible, or in the intraovarian artery, was chosen. When the luteus body was present, the RI was measured in its periphery. The data obtained were analyzed by Kruskal-Wallis and Mann-Whitney tests. RESULTS: there was no significant difference among the groups, concerning the mean RI of the ovarian arteries (Kruskal-Wallis, p=0.50). There was a tendency for higher right uterine artery RI in the HESNO group (Kruskal-Wallis, p<0.07), but it was similar in the left uterine artery (Kruskal-Wallis, p=0.14). Arterial RIs significantly lower have been observed in the luteus body periphery, when compared to the contralateral ovarian arteries in all the groups (Mann-Whitney, p<0.0001). CONCLUSIONS: there was no difference among the groups, regarding the ovarian and uterine RIs. The portal hypertension in patients with hepatosplenic schistosomiasis does not affect the natural phenomenon of arterial RI decrease in the ovary where ovulation occurs.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2009;31(9):427-432
DOI 10.1590/S0100-72032009000900002
PURPOSE: to evaluate the repercussion of portal hypertension in the indexes of the ovarian, uterine and luteus body periphery arterial resistance, at the medium luteal phase of the menstrual cycle. METHODS: in an observational study with transversal cohort, 28 patients with hepatosplenic schistosomiasis mansoni, submitted to splenectomy and ligation of the left gastric vein (HESO), a similar group of 28 patients who had not had the surgery (HESNO) and 29 healthy volunteers (HV) were submitted to Doppler fluxmetry in the medium luteal phase of the menstrual cycle. Pourcelot's resistance index has been used as RI=[(S-D)/S], in which S means the highest systolic speed, and D, the end of diastole. The best record in the ascendant branch of the uterine artery, in the ovarian artery, when accessible, or in the intraovarian artery, was chosen. When the luteus body was present, the RI was measured in its periphery. The data obtained were analyzed by Kruskal-Wallis and Mann-Whitney tests. RESULTS: there was no significant difference among the groups, concerning the mean RI of the ovarian arteries (Kruskal-Wallis, p=0.50). There was a tendency for higher right uterine artery RI in the HESNO group (Kruskal-Wallis, p<0.07), but it was similar in the left uterine artery (Kruskal-Wallis, p=0.14). Arterial RIs significantly lower have been observed in the luteus body periphery, when compared to the contralateral ovarian arteries in all the groups (Mann-Whitney, p<0.0001). CONCLUSIONS: there was no difference among the groups, regarding the ovarian and uterine RIs. The portal hypertension in patients with hepatosplenic schistosomiasis does not affect the natural phenomenon of arterial RI decrease in the ovary where ovulation occurs.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(3):147-152
DOI 10.1590/S0100-72032007000300006
PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed an observational, longitudinal and prospective study evaluating 34 healthy and ovulatory women. All women were submitted to Doppler scan of the eye to evaluate the vascular resistance of the central retinal arteries, either lying down or on a seated position, during four phases of the menstrual cycle. Confirmation of ovulation was performed by measuring serum progesterone during the luteal phase. We analyzed the pulsatility and resistance index and the maximum, minimum and mean velocity. RESULTS: mean age was 29.7 years. No differences were observed between the indexes obtained in both eyes, therefore a mean index was used for comparisons. As the comparison between the positions used for the exams showed a higher PI for the seated position, the analyses were performed separately. The pulsatility index in the lying position was different among the different phases of the menstrual cycle. The arterial resistance was significantly lower during the intermediate follicular and the periovulatory phases, as compared to the early follicular and luteal phases. When the comparison was performed with the patient in the seated position, no differences were observed. CONCLUSIONS: Our results demonstrate a reduction in the vascular resistance of the cerebral microcirculation and a posterior reversal, as shown by changes in the PI.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(3):147-152
DOI 10.1590/S0100-72032007000300006
PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed an observational, longitudinal and prospective study evaluating 34 healthy and ovulatory women. All women were submitted to Doppler scan of the eye to evaluate the vascular resistance of the central retinal arteries, either lying down or on a seated position, during four phases of the menstrual cycle. Confirmation of ovulation was performed by measuring serum progesterone during the luteal phase. We analyzed the pulsatility and resistance index and the maximum, minimum and mean velocity. RESULTS: mean age was 29.7 years. No differences were observed between the indexes obtained in both eyes, therefore a mean index was used for comparisons. As the comparison between the positions used for the exams showed a higher PI for the seated position, the analyses were performed separately. The pulsatility index in the lying position was different among the different phases of the menstrual cycle. The arterial resistance was significantly lower during the intermediate follicular and the periovulatory phases, as compared to the early follicular and luteal phases. When the comparison was performed with the patient in the seated position, no differences were observed. CONCLUSIONS: Our results demonstrate a reduction in the vascular resistance of the cerebral microcirculation and a posterior reversal, as shown by changes in the PI.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(7):387-392
DOI 10.1590/S0100-72032005000700004
PURPOSE: to assess peak systolic velocity (PSV) and the resistance index (RI) in the middle cerebral artery (MCA), suprarenal aorta (SRA) and infrarenal aorta (IRA) of the fetus and in the umbilical artery (UA) between the 22nd and 38th week of gestation. METHODS: a prospective study which evaluated the parameters of 33 normal fetuses in the 22nd, 26th, 30th, and 38th week of gestation. Pregnant women with a singleton fetus with no diseases or complications and who agreed to participate were included in the study. Exclusion criteria were fetal malformations, discontinuation of prenatal care visits and mothers who smoked, used alcohol or illicit drugs. Ultrasound examinations were performed by a single observer. For the acquisition of the Doppler velocimetry tracing in the MCA, SRA, IRA and UA, the sample volume was 1 to 2 mm, placed in the center of the arteries. The insonation angle was 5º to 19º in the MCA, below 45º in the SRA and IRA, and less than 60º in the UA. We used a wall filter of 50-100 Hz. The parameters were calculated automatically with the frozen image, three measurements being made. The final result was obtained by the arithmetic mean of the three values. Data were analyzed by analysis of variance (ANOVA), post hoc Bonferroni test, Pearson's correlation, and regression analysis. The level of significance was set at p<0.05 in all analyses. RESULTS: PSV increased from 26.3 to 57.7 cm/s in the MCA between the 22nd and the 38th week of gestation (p<0.05). In the SRA and in the IRA, PSV increased between the 22nd and 34th week of gestation, from 74.6 and 59.0 cm/s to 106.0 and 86.6 cm/s, respectively (p<0.05). In the UA, PSV increased between the 22nd and the 34th week of gestation, but decreased from 55.5 to 46.2 cm/s between the 34th and the 38th week of gestation. In the MCA, the RI was lower in the 22nd (0.81) and 38th week of gestation (0.75) and higher (0.85) in the 26th week (p<0.05). In the SRA, the RI values were stable in all weeks and in the IRA they were stable in most weeks (p>0.05). In the UA, RI decreased from 0.69 to 0.56 between the 22nd and 38th week of gestation (p<0.05). CONCLUSION: in normal fetuses, in the second half of gestation PSV increased in the MCA, SRA and IRA, decreasing in the UA between the 34th and 38th week of gestation. RI was lower in the 22nd and 38th weeks of gestation in the MCA, decreased between the 22nd and the 38th week in the UA, and was constant in most of the gestational weeks in the SRA and IRA.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(7):387-392
DOI 10.1590/S0100-72032005000700004
PURPOSE: to assess peak systolic velocity (PSV) and the resistance index (RI) in the middle cerebral artery (MCA), suprarenal aorta (SRA) and infrarenal aorta (IRA) of the fetus and in the umbilical artery (UA) between the 22nd and 38th week of gestation. METHODS: a prospective study which evaluated the parameters of 33 normal fetuses in the 22nd, 26th, 30th, and 38th week of gestation. Pregnant women with a singleton fetus with no diseases or complications and who agreed to participate were included in the study. Exclusion criteria were fetal malformations, discontinuation of prenatal care visits and mothers who smoked, used alcohol or illicit drugs. Ultrasound examinations were performed by a single observer. For the acquisition of the Doppler velocimetry tracing in the MCA, SRA, IRA and UA, the sample volume was 1 to 2 mm, placed in the center of the arteries. The insonation angle was 5º to 19º in the MCA, below 45º in the SRA and IRA, and less than 60º in the UA. We used a wall filter of 50-100 Hz. The parameters were calculated automatically with the frozen image, three measurements being made. The final result was obtained by the arithmetic mean of the three values. Data were analyzed by analysis of variance (ANOVA), post hoc Bonferroni test, Pearson's correlation, and regression analysis. The level of significance was set at p<0.05 in all analyses. RESULTS: PSV increased from 26.3 to 57.7 cm/s in the MCA between the 22nd and the 38th week of gestation (p<0.05). In the SRA and in the IRA, PSV increased between the 22nd and 34th week of gestation, from 74.6 and 59.0 cm/s to 106.0 and 86.6 cm/s, respectively (p<0.05). In the UA, PSV increased between the 22nd and the 34th week of gestation, but decreased from 55.5 to 46.2 cm/s between the 34th and the 38th week of gestation. In the MCA, the RI was lower in the 22nd (0.81) and 38th week of gestation (0.75) and higher (0.85) in the 26th week (p<0.05). In the SRA, the RI values were stable in all weeks and in the IRA they were stable in most weeks (p>0.05). In the UA, RI decreased from 0.69 to 0.56 between the 22nd and 38th week of gestation (p<0.05). CONCLUSION: in normal fetuses, in the second half of gestation PSV increased in the MCA, SRA and IRA, decreasing in the UA between the 34th and 38th week of gestation. RI was lower in the 22nd and 38th weeks of gestation in the MCA, decreased between the 22nd and the 38th week in the UA, and was constant in most of the gestational weeks in the SRA and IRA.