3-Dimensional computerized tomography and virtual reality endoscopy of the reconstructed lower urinary tract

We describe postoperative surgical anatomy after orthotopic reconstruction of the lower urinary tract using 3-dimensional (D) computerized tomography (CT) and virtual reality endoscopy.

Electronic beam CT was performed in 39 men and 15 women a mean of 60 years old with an orthotopic ileal neobladder (50) or ureteroileal rectosigmoidostomy (4), followed by 3-D reconstruction of the pelvic anatomical structures using specialized computer hardware and software. The mean interval between surgery and CT was 15 months (range 3 to 110) and the mean interval between 2 subsequent 3-D CT studies in 22 patients was 6 months (range 3 to 9).

CT time with the patient on the table was 45 minutes and computerized 3-D reconstruction time with the patient off the table was 4 to 5 hours. The pouch had a smooth ovoid shape in 66 and 82% of the patients on the first and second 3-D CT studies, respectively. Mean length of the antireflux nipple was 4 cm. (range 2.5 to 8) and mean length of the afferent limb was 6 cm. (range 3 to 15). There were no radiologically significant sex specific differences in the shape or dimensions of the urinary reservoirs, except for a tendency toward more acute angles between the pouch and remnant urethra. No pathological findings were visible on 3-D CT that were not also evident on conventional CT.

Three-D CT may be clinically useful for surgical planning of a lower abdominal reoperation or unexplained findings and symptoms in patients with bladder substitutions. Cost and time expenditures for processing preclude its routine use in all cases. Virtual reality endoscopy may be a valuable tool for teaching and scientific purposes.