Back to 2014 Fall Congress Meeting Posters

Background: Bladder augmentation has proven to be of great value in preserving renal function and providing continence in patients with low bladder capacity and poor bladder compliance. However, this operation carries with it specific risks, the most significant of which is bladder perforation. The prompt and accurate diagnosis of this potentially fatal complication is vital in order to prevent long-term morbidity and mortality. To date, it remains common practice to diagnose this condition using standard cystography. We sought to evaluate the accuracy of CT cystography (CTc) in the evaluation of spontaneous perforation of the augmented bladder (SBP).
Methods: Our institutional review board approved this HIPAA-compliant study. We identified all patients younger than age 20 from 2003-2013 who underwent CTc for the evaluation of spontaneous perforation of an augmented bladder. We reviewed presenting symptoms, clinical and laboratory findings, and CTc reports for presence of contrast extravasation, ascites, and pneumoperitoneum. Ascites was graded retrospectively and categorized as follows; small- confined to the rectovesical pouch (RVP), moderate- beyond the RVP, large- beyond the pelvis. Generalized estimating equation methods for categorical data were used to compare the prevalence of findings in children with or without spontaneous bladder perforation.
Results: Eighty-nine patients underwent a total of 133 CTc (M: F 47:42). Average age at time of CTc was 11.6 years (range 4.2-19.8 years). SBP was diagnosed in 19/133 (14.3%) studies. Presenting symptoms of abdominal pain, tenderness, distension, peritoneal signs, and decreased urine output were significantly more common in children with SBP (p<0.05). In 79% (15/19) of patients identified as having a perforation, CTc demonstrated contrast extravasation; 15.8 % (3/19) had only pneumoperitoneum, and 5.3% (1/19) had only large ascites. If amount of abdominal fluid alone was used for analysis, only 1 of 98 patients with fluid limited to the rectovesical pouch was found to have a SBP.
Conclusion: CTc is extremely accurate in identifying patients who have experienced a spontaneous bladder rupture follow bladder augmentation. While extraluminal contrast extravasation was seen on CTc in most cases of SBP (15/19, 79%), the remainder demonstrated either pneumoperitoneum or large ascites. If the sole variable of free abdominal fluid volume was used to predict SBP, then only 1% of patients with fluid limited to the rectovesical pouch were found to have SBP. Future studies to evaluate whether pelvic US may be effective as a screening tool in low risk patients are warranted