Comparison of manual and ultrasonographic evaluation of bladder size in patients prior to laparoscopy

Background: Catheterization of the bladder may reduce laparoscopic complications although an enlarged bladder may be impalpable in overweight patients or following pre vious lower abdominal surgery. Methods: This study assessed bladder size by manual examination and transcutaneous ultrasound (US). Consecutive patients (n = 90; median age 55 years [20-85]; 61 females) undergoing laparoscopy were studied prospectively. All patients voided preoperatively and catheterization was performed if estimated US bladder volumes exceeded 300 ml. Results: Manual assessment failed to detect bladder enlargement in any patients (sensitivity: 0%; specificity: 4.4%), whereas ultrasound identified four patients at risk of bladder injury due to unsuspected enlargement (4.4%), Three of these patients were either overweight or obese and one patient had previous lower abdominal surgery. Of 12 patients (13%) catheterized, three had or developed urinary tract infections. Conclusions: Preoperative voiding does not guarantee bladder emptying. Manual examination does not detect bladder enlargement reliably in the obese patient. Ultrasonography may improve patient selection for catheterization.