Diagnostic ultrasound ( PDFDrive )

1912 PART V Pediatric Sonography
may be seen with micturition. 222 Benign polyps in the male urethra
can arise from a stalk near the verumontanum and cause urinary
tract obstruction.
Trauma
Trauma to the lower urinary tract in children is most oten caused
by blunt trauma. Foreign bodies and complications of surgery
are less frequent causes. he bladder in children is in a more
intraabdominal position than in adults, and therefore bladder
rupture is usually intraperitoneal. Spontaneous bladder rupture
is rare in children and is seen primarily in neonates with urinary
ascites secondary to urethral obstruction or neurogenic bladder.
FIG. 54.68 Rhabdomyosarcoma of Bladder Wall. Large, complex,
polypoidlike mass (arrows) arises from base of the bladder (B) in this
9-year-old boy with painless hematuria. Asymmetrical bladder wall
thickening was noted posterolaterally on patient’s left (arrowhead).
B
Preexisting abnormalities of the vesical wall, such as tumors,
stones, tuberculosis, diverticula, and surgical scars, can predispose
a child to spontaneous rupture of the bladder. 223 Sonography
can demonstrate urinary ascites in cases of intraperitoneal rupture
or a loculated luid collection (urinoma) in the retropubic or
perivesical space in extraperitoneal rupture.
Postoperative Bladder
Sonography has assumed an important role in the evaluation of
the postoperative bladder. Ureteral reimplantation is a common
surgical procedure for the correction of persistent vesicoureteral
relux. he reimplanted ureteral segment is submucosal and
contiguous to the bladder mucosa. Sonograms reveal an echogenic,
ixed, tubular, submucosal structure without acoustic shadowing
at or just above the trigone. Occasionally the reimplanted ureter
appears only as an area of focal thickening of the posterior bladder
wall. 224 Sonography is also useful for the demonstration of the
echogenic mound present ater treatment with Delux
(dextranomer–hyaluronic acid copolymer) as a irst-line treatment
for high-grade vesicoureteral relux 225 (Fig. 54.70).
Bladder augmentation is now a widely accepted surgical
procedure for the reconstruction of small-capacity bladders caused
by exstrophy, neurogenic bladder, or tumor. Segments of bowel,
usually the sigmoid, cecum, or ileum or the ileocecal segment,
are anastomosed to the bladder to increase the size of the urinary
reservoir. Sonography of the augmented bladder reveals a thick
or irregularly shaped bladder wall (Fig. 54.71). Pseudomasses
within the bladder lumen, representing bowel folds, mucous
collections, or bowel that was surgically intussuscepted into the
reconstructed bladder to prevent relux, are a common inding.
Fine debris and linear strands oten loat within the urine and
probably represent mucus. Active peristalsis within the bowel
segment can be identiied on real-time imaging. Complications
of bladder reconstructive surgery can be detected on ultrasound
and include enterocystic anastomotic strictures, ureteral relux
BL
BL
A
FIG. 54.69 Prostatic Rhabdomyosarcoma With Bladder Invasion in 11-Month-Old Boy With Pelvic Pain. (A) and (B) Transverse and sagittal
sonograms of the pelvis demonstrate a large, solid mass arising inferior to the bladder neck (BL) invading the bladder base.
B