Fetal celiac and splenic artery flow velocity and pulsatility index: longitudinal reference ranges and evidence for vasodilation at a low portocaval pressure gradient.

OBJECTIVES: To establish longitudinal reference ranges for the fetal celiac and splenic arteries flow velocity and pulsatility index (PI), and to determine their hemodynamic relationship to venous liver perfusion and distribution and to other essential arteries. METHODS: This was a prospective longitudinal study of 161 low-risk pregnancies. Doppler recordings of the celiac and splenic arteries were made on three to five occasions at 3-5-week intervals to establish reference ranges for blood velocity and PI measurements. Peak systolic velocity in the ductus venosus, a shunt between the umbilical and inferior caval veins, was used to represent the umbilicocaval (i.e. portocaval) pressure gradient, and the left portal vein blood velocity represented the umbilical distribution to the right liver lobe. The correlations between the celiac, splenic and hepatic arteries were determined, and their association with the middle cerebral and umbilical artery PIs (MCA-PI and UA-PI) was assessed. RESULTS: Longitudinal reference ranges for the fetal celiac and splenic arteries were established based on 510 and 521 observations, respectively, during gestational weeks 21-39. Terms for calculating conditional reference ranges to be used for repeat observations are provided. Celiac and splenic artery PIs were low when portocaval pressure and umbilical supply to the right lobe were low (P < 0.0001). Their peak systolic velocity and PI were correlated (r = 0.7 (95% CI, 0.6-0.8) and r = 0.5 (95% CI, 0.3-0.6), respectively), while the PI of the hepatic artery correlated weakly with those of the celiac and splenic arteries. They were positively associated with the MCA-PI and UA-PI (P < 0.0001). CONCLUSION: We provide longitudinal reference ranges for the fetal celiac and splenic arteries Doppler measurements and show that they are involved in maintaining portal liver perfusion independently from the hepatic artery.

A rare case of distal one-third of the transverse colon supplied by a branch from splenic artery.

We observed a rare variation of splenic artery during the routine dissection in the Laboratory of the Anatomy Department. It arose from the splenic artery toward the distal part of transverse colon which typically supplied by the inferior mesenteric artery. Embryologically distal part of the transverse colon is a segment of hindgut. In this case, splenic artery which an artery of foregut supplies an area of hindgut. The knowledge of splenic artery variations has significant importance during surgery of the organs of the upper abdominal region. In this study, we discussed clinical significance and embryological aspects of this anomalous artery.

[Doppler ultrasound to detect Rh: a systematic review]. / Ultrasonido doppler para detección rh: una revisión sistemática.

BACKGROUND: Red cell alloimmunization is an important cause of perinatal morbidlity and mortality. Invasive procedures used to diagnose fetal anemia are associated with serious fetal and maternal complications. The development of noninvasive techniques as Doppler ultrasound can help us in the fetal anemia diagnosis. OBJECTIVES: To evaluate the effect of the Doppler ultrasound in prediction of fetal anemia caused by red cell alloimmunization. Strategy search: Relevant studies were identified by reviewing the registry of COCHRANE, and OVID, PROQUEST, MEDLINE and EMBASE data bases from 1966 to 2004. SELECTION CRITERIA: All prospective studies with clinically relevant results with comparison of Doppler ultrasound in fetal umbilical artery, fetal descendent aorta, middle cerebral fetal artery or esplecnic fetal artery with hemoglobin or fetal hematocrit. DATA COLLECTION AND ANALYSIS: Data were extracted from each report. The quality revision of the studies and the data compilation were made by the reviewers. MAIN RESULTS: Eighteen articles were included. Two studies reached the level of evidence 1 for diagnostic tests. The diagnostic tests had variations depending on the different cut-off of each study. Studies with level 1 of evidence reported detection of 100% for moderate to severe fetal anemia. CONCLUSIONS: Implementation of Doppler ultrasound for prediction of fetal anemia in complicated pregnancies with alloimmunization could reduce the number of invasive procedures and therefore its complications. The level of present evidence reveals to us that the studies do not fulfill the criteria of methodological quality.

Splenic artery Doppler in the prediction of the small-for-gestational age infant.

OBJECTIVES: We hypothesized that, as with other areas of the peripheral circulation, fetal splenic artery blood flow undergoes changes in small-for-gestational age (SGA) fetuses due to a redistribution of cardiac output, and that the Doppler peak systolic velocity (PSV) reflects such changes and thus may be used to predict fetuses being SGA. METHODS: Splenic artery Doppler PSV, end-diastolic velocity (EDV), resistance index (RI) and umbilical artery RI were measured prospectively in fetuses at risk for being SGA at birth. Normal reference data were generated from appropriately grown fetuses delivering at > or = 37 weeks without complications, and SGA was defined as birth weight < 10th percentile. The Doppler indices were expressed as multiples of the normal median (MoM) for gestational age. Using receiver operating characteristic curves, optimal Doppler thresholds for the detection of SGA cases were determined and the areas under the curves calculated. The analysis was limited to singleton pregnancies delivered within 2 weeks of the last Doppler examination. RESULTS: There were 88 study patients of which 60 had SGA babies. The mean gestational age at Doppler examination was 31.4 weeks with a mean interval of 5.6 days from Doppler to delivery. The splenic artery PSV was lower in SGA, compared to normal cases: mean PSV (MoM), 0.93 vs. 1.09, respectively (P = 0.0001). The sensitivity, specificity and area under the curve were 70.0%, 72% and 0.734, respectively (P < 0.003), for the PSV in the prediction of delivery of a SGA fetus. For the splenic artery RI, values were 70%, 46% and 0.539, respectively (not significantly different), and for umbilical artery RI these were 70%, 61% and 0.689, respectively (P < 0.01). Splenic artery EDV was significantly reduced in SGA vs. normally grown fetuses (0.924 MoM vs. 1.145 MoM, P = 0.007). CONCLUSIONS: Fetal splenic artery PSV decreases in SGA infants, and is a strong predictor of the delivery of a SGA infant. It appears to be superior to the standard Doppler index, the RI, in predicting this outcome.

Blood flow velocity waveforms of the abdominal arteries in appropriate- and small-for-gestational-age fetuses.

The aim of this study was to describe flow velocity waveforms of abdominal arteries in the appropriate- and small-for-gestational-age fetus. Splenic artery, superior mesenteric artery, hepatic artery and renal artery velocity waveforms were obtained from 57 appropriate-for-gestational-age and nine small-for-gestational-age fetuses with color flow Doppler ultrasonography. The pulsatility index was used to quantify the arterial waveforms. Repeated measure analysis of variance indicated significant differences in the pulsatility index values in both the appropriate-for-gestational-age and small-for-gestational-age fetuses. A multiple comparison test revealed a significantly lower value for the pulsatility index in the splenic artery when compared to that of the other vessels for both the appropriate- and small-for-gestational-age fetuses. In the small-for-gestational-age fetuses, a lower pulsatility index value was observed at the superior mesenteric artery level when compared to the renal artery. Because of its lower frequency of successful insonation, the hepatic artery was not considered for the analysis. In the normal fetus, the splenic artery had the lowest pulsatility index when compared to the other arteries we investigated. This difference remained in small-for-gestational-age fetuses, reflecting a lower vascular resistance at the fetal spleen in both normal and small-for-gestational-age fetuses. It appears that in small-for-gestational-age fetuses the renal artery has a higher pulsatility index than the superior mesenteric artery, suggesting a preferential distribution of blood flow to the bowel.