Complicated urinary tract infections.

Complicated urinary tract infections (UTIs) are defined as those infections causing severe complications, such as urosepsis, renal scarring, and end-stage renal disease. Major complicating factors are infection stones, infected atrophic kidney, renal papillary necrosis, indwelling catheters, and other causes of bacterial persistence, as well as vesicoureteral reflux and urinary tract obstruction in recurrent UTI. Operative therapy is mandatory in all types of persistent UTI besides chronic bacterial prostatitis, as well as in UTI associated with urinary tract obstruction. Recurrent UTI complicated by vesicoureteral reflux, on the other hand, should be managed conservatively.