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Question 9#

The following are true of bladder calculi, except:

a. In the Western world bladder calculi are most commonly composed of uric acid
b. Malnutrition and low phosphate diets predispose to endemic bladder stones in the developing world
c. More than 90% of men with bladder calculi require surgery for bladder outflow obstruction
d. Cystolitholopaxy should be undertaken before bladder outflow surgery where the procedures are combined
e. The holmium laser may be used to treat large bladder calculi as an alternative to open stone removal

Correct Answer is C

Comment:

Answer C

The incidence of bladder calculi in the Western world has been declining because of improved nutrition and better control of urinary tract infection. However, in the developing world, bladder stones remain a significant problem especially in the paediatric population because of malnutrition and low phosphate diets.

Certain conditions predispose to bladder calculi formation in the adult population. Bladder outflow obstruction leading to incomplete bladder emptying and urinary stasis is a common cause of bladder stones and was once considered an absolute indication for bladder outflow surgery. However, a recent study that evaluated men with bladder calculi using pressure-flow studies found that only about half had bladder outflow obstruction [13]. Moreover, these findings were maintained even after stone surgery suggesting that the presence of the stone within the bladder did not affect the urodynamics results. Patients with long-term indwelling catheters, spinal cord injury patients and those with enteric bladder augmentations are also at higher risk of bladder calculi.

Open cystotomy is still considered by many urologists to be an excellent operation for large (>3 cm) bladder stones and may be combined with an open prostatectomy. However, the holmium laser now allows fragmentation of even very large bladder calculi and where bladder outflow surgery is also required it can be used to resect or enucleate the prostate.