Compared with monopolar transurethral bladder tumor resection , bipolar resection was associated with a significantly lower incidence of severe bladder injury ( @ % vs @ % , OR @ ) , other complications ( @ % vs @ % , OR @ ) , slightly shorter postoperative stay ( mean @ vs @ days , difference -@ % ) and slightly lower total costs ( mean $ @,@ vs $ @,@ ; difference -@ % , all p < @ ) .