A 17-year-old girl presented to her nephrologist with complaints of nausea, vomiting, and dysuria. Her medical history was signiﬁcant for renal failure secondary to nephritis associated with systemic lupus erythematosus. Two years prior to her presentation, she had received a renal transplant from a living-related donor. She also reported a history of recurrent urinary tract infections while on prophylactic therapy.
W. Forrest Carson, MD, Robert Bechtold, MD,
Ray Dyer, MD
from the Department of Radiology; and Joel C. Hutcheson, MD from
the Department of Urology, Wake Forest University School of
Medicine, Winston-Salem, NC.
A 17-year-old girl presented to her nephrologist with complaints
of nausea, vomiting, and dysuria. Her medical history was
significant for renal failure secondary to nephritis associated
with systemic lupus erythematosus. Two years prior to her
presentation, she had received a renal transplant from a
living-related donor. She also reported a history of recurrent
urinary tract infections while on prophylactic therapy. Despite
having just completed a 10-day course of antibiotics, her urine
culture was positive for
. A urologic consultant recommended a computed tomography (CT)
examination to exclude anatomic causes for the recurrent urinary
tract infections (Figure 1).
Hanging bladder stone
An unenhanced CT image through the pelvis, above the bladder,
shows mild hydronephrosis in the right iliac fossa transplant
kidney (Figure 1A). The ureteroneocystostomy can be identified
entering the right anterior aspect of the bladder (Figure 1B). An
image obtained at a slightly lower level reveals a stone hanging
from the anterior bladder wall near the ureterovesical junction
(Figure 1C). At cystoscopy, the stone was dangling from the
anterior wall of the bladder, attached by nonabsorbable suture.
Removal of the stone necessitated division of the suture (Figure
Bladder calculi are divided into migrant, primary endemic, and
Migrant calculi are the most common, forming in the kidney and
migrating down the ureter into the bladder. Once in the bladder,
they are usually mobile and, if imaged before they pass, they will
fall to a dependent position.
They can remain in the bladder in cases of bladder outlet
obstruction, where they may enlarge. Primary endemic calculi
usually occur in children and young adults and are related to the
diet in underdeveloped countries.
Secondary bladder calculi are often seen in adults as a consequence
of urinary stasis. In men, this is most commonly the result of
prostatic enlargement with outflow obstruction. In women, stones
may develop as a result of cystocele formation. A neurogenic
bladder with associated urinary stasis may be a cause in both
An uncommon, but well-recognized, cause of secondary bladder
calculi is formation on a foreign body. The foreign body may serve
as a nidus for crystallization with resultant stone formation.
Bladder stones appearing to defy gravity and hanging from the
anterior bladder wall were first described by Levack in 1955.
As in this case, the stones in the original report formed on
nonabsorbable suture material. Stone formation has also been
reported on bladder catheter balloons,
mesh used for treatment of incontinence,
and other nonabsorbable material chronically exposed to urine.
The diagnosis of a hanging stone may be difficult by standard
radiographic examinations. The CT finding of a curious,
nondependent stone location should prompt review of the patient's
history for a surgical procedure involving nonabsorbable material.
In this case, the anastamosis of the transplant ureter with the
bladder was created using a nonabsorbable, running prolene suture
that served as the nidus for stone formation. In the modern era of
CT examination, this old stone, "just hanging around," is revealed
in a new way.