Reconstructed urinary bladder following radical cystectomy for bladder cancer. Multidetector CT evaluation of normal findings and complications

Abstract

Purpose.

The aim of this paper is to report the normal and pathological multidetector computed tomography (MDCT) findings in the morphofunctional evaluation of the orthotopic ileal reservoir in patients treated with radical cystectomy for transitional cell carcinoma.

Materials and methods.

During a clinical and imaging follow-up of 43 months, 30 patients (27 men and three women) with prior cystectomy and urinary reconstruction with an orthotopic ileal neobladder [six Studer and 24 Paduan Ileal Bladder (VIP)] underwent multislice CT scan with multiplanar reconstruction (MPR), volume rendering and virtual endoscopic evaluation of the contrast-filled neobladder. The following CT data were considered: neobladder position within the pelvis, neobladder capacity, sphericity index, vesico-urethral angle, vesico-ureteral reflux, pseudo-diverticular herniation, visualisation of ileal folds and parietal thickness. The CT scan results were correlated with those of the urodynamic assessment (uroflowmetry and enterocystometry).

Results.

Right-sided dislocation was observed in 12/30 neobladders (six VIP and six Studer); mean capacity was around 254 ml; six VIP were spherical whereas the others were oval. The vesico-urethral angle was less than 90° in five patients (normal range: 90°–170°). One patient had grade-3 unilateral, passive, vesico-ureteral reflux and nine patients had active or passive bilateral reflux. One patient had pseudo-diverticular herniation. The ileal folds in the afferent limb of the neobladder could be visualised in all six patients with Studer neobladders. Mean parietal thickness was 3.59 mm (SD 1.34 mm). Increased endoluminal pressure, evaluated by uroflowmetry, was associated with lateralisation of the new reservoir during straining in nine patients, with decreased neobladder capacity in six patients, vesico-ureteral reflux in five patients and pseudo-diverticular herniation in one case. Decreased urinary flow was correlated with vesico-urethral angle less than 90° in four patients and with low sphericity index in five patients. No significant correlation was found between parietal thickness, presence of ileal folds and urodynamic data. Absorbed dose due to the two additional scans of our CT protocol was 10 mSv for 4-row CT and 15 mSv for 16- row CT.

Conclusions.

MDCT of the contrast-filled neobladder is useful for the morphological and, in part, functional evaluation of the neobladder during postoperative follow-up and helps detect surgical complications. Radiation protection concerns do not, however, support the routine use of the method, even if the MDCT data are in part correlated to the urodynamic data and may in many cases provide a morphological explanation to the presence of functional alterations.