Pattern Recognition of Abdominal Vasculature on Color Doppler in the Fetus as a Tool for Early Diagnosis of Bladder Exstrophy in the First and Early-Second Trimester: Initial Observations

Abstract

Early prenatal diagnosis of bladder exstrophy is challenging because of its variable size and presentation. This article brings forth new signs on color Doppler (CD) to help establish the diagnosis in a suspected case. Two cases of omphalocele-exstrophy-imperforate anus-spinal defects complex presenting as a solid-cystic ventral mass at 11 weeks and a solid lower abdominal wall mass at 20 weeks, with nonvisualization of the urinary bladder, were studied by gray-scale and CD in sagittal and transverse-bladder views of the abdomen. The sagittal view on CD revealed an altered intrafetal course of umbilical artery (UA), widened UA-aorta angle (K angle), a break in the intersection of UA, and umbilical vein (UV) at the umbilicus—broken “X-sign” with distortion of the equilateral triangle normally formed by aorta, UA, and UV. The transverse-bladder view showed an altered divergent course of single-UA. Combination of these findings substantiated early diagnosis of bladder exstrophy, thus facilitating prenatal counseling. Key Messages

Color Doppler evaluation of umbilical arteries in relation to bony landmarks in the fetal pelvis as a clue to the mid‐trimester diagnosis of bladder exstrophy: A novel observation

“…1 It can be isolated or syndromic and omphalocele-exstrophy-imperforate-anus-spinal (OEIS) complex is a common association. 1,2 OEIS complex does not distinguish between cloacal exstrophy and bladder exstrophy. 3 The lack of uniformity of imaging features and the low incidence makes the diagnosis challenging especially in the absence of an obvious infraumbilical mass bulge.…”

“…The UAs subsequently traveled alongside surface irregularity of presumably exteriorized bladder, with convergence at the cord insertion on omphalocele. There appears to be “X‐sign” 2 loss as the point of emergence of UAs from pelvis is far below the point of entry of umbilical vein in the abdomen at the cord‐insertion (Figure 6A). The “elephant trunk” like soft tissue projection did not fill with color suggesting prolapsed bowel.…”

“…The sagittal view CD reveals obliquely ascending UAs (one behind the other) alongside urinary bladder, from their origin against iliac crest forming an acute “K angle” between UA and aorta (AO) in a normal fetus 1 . The UAs emerge at the umbilicus to intertwine with umbilical vein (UV) to form “X‐sign” 2 and an equilateral triangle between AO, UA, UV 2 (Figure 1A,B and Video S1). Normally UAs do not descend to the ischial tuberosity (IT) from their origin and never emerge from pelvis below the umbilicus.…”

“…CD in axial‐oblique view through iliac crest (white dotted line in Figure 1A) reveals UAs that arise from internal iliac arteries (which are parallel to iliac crest), flank and converge across urinary bladder (perivesical course), and travel together to emerge at the umbilicus to form a “Y”configuration 2 (Figure 1C). Axial‐oblique view through ischial tuberosity and genital tubercle (green dotted line in Figure 1A) do not show urinary bladder, UAs and the “Y” configuration (Figure 1D and Video S2).…”

“…The reported incidence is 1 in 40 000 live births 1 . It can be isolated or syndromic and omphalocele‐exstrophy‐imperforate‐anus‐spinal (OEIS) complex is a common association 1,2 . OEIS complex does not distinguish between cloacal exstrophy and bladder exstrophy 3 .…”