Editing Stones: Lower Urinary Tract Calculi (section)

==== Risk factors ====

# '''<span style="color:#ff0000">Bladder outlet obstruction (most common cause)</span>'''
#* Associated with decreased fluid intake with the resultant production of concentrated acidic urine
# '''<span style="color:#ff0000">Neurogenic or spinal cord injury</span>'''
#* '''Intermittent catheterization decreases the risk of bladder stone formation in comparison to an indwelling catheter.'''
#* '''Suprapubic provides no benefit compared to urethral catheterization in terms of the development of bladder calculi'''
# '''<span style="color:#ff0000">Augmented bladders and urinary diversion</span>'''
#* The incidence of bladder calculus after augmentation cystoplasty ranges from 10-52.5%
#** '''High risk of stone formation due to (6):'''
#**# '''Metabolic abnormalities'''
#**# '''Recurrent infections with urease-splitting organisms'''
#**# '''Prolonged urinary stasis''' and incomplete bladder emptying
#**# '''Prolonged exposure of urine to non-absorbable materials'''
#**# '''Anatomical changes following diversion'''
#**# '''Reflux of mucous into the upper tract'''
#** '''<span style="color:#ff0000">Most common stone types are magnesium ammonium phosphate (struvite) and calcium phosphate</span>'''
#** The role of intestinal mucus in stone formation remains controversial
#* Unlike the nonaugmented population, '''females who have undergone augmentation cystoplasty are more likely to develop bladder calculi than males,''' likely owing to the higher incidence of cloacal abnormalities, which require additional procedures to establish continence.
# '''<span style="color:#ff0000">Kidney or pancreas transplant</span>'''
#* Risk factors for stone formation
#*# Nonabsorbable suture material used for the anastomosis.
#*# Incomplete bladder emptying due to diabetic cystopathy.
#*# Bacteriuria associated with included duodenal segments.
#*# Metabolic acidosis due to bicarbonate leak
#'''<span style="color:#ff0000">Foreign body</span>'''
#*Suture material or clip used during radical prostatectomy

'''<span style="color:#ff0000">In contrast to renal stones, bladder stones in adults are usually composed of uric acid (in non-infected urine) or struvite (in infected urine).</span>'''

* '''Calcium oxalate or cystine stones in the bladder suggests the ureteral passage of calculi originating in the kidney with subsequent entrapment in the bladder'''