Occasionally one is called to the operating room to see a pelvic fracture patient who is already undergoing pelvic fixation or surgery for other injuries. A urethrogram has not been, or cannot be done, and the orthopaedic team has tried, but failed, to pass a catheter urethrally. It is reasonable for the more experienced urologist to make a single attempt to pass a catheter, but if this fails, assume the patient has a urethral rupture. In the ideal world a urethrogram followed by a cystogram would be done on the operating table to establish whether the urethra and bladder are intact or injured. But the world is not ideal. There may be lots of metal work in the way (obscuring that bit of the urethra you're interested in). The patient may not be ideally positioned for a urethrogram. Trying to reposition a patient who is draped in sterile towels and who has just undergone pelvic fixation is never easy. Finally, just to make life even more difficult the radiographer may have been called away to another case and will be
5. TRAUMATIC UROLOGICAL EMERGENCIES 97
busy for hours! One can vainly struggle to do a urethrogram, and sometimes you will be lucky and the images will be good enough for interpretation. More often than not, the exercise proves a frustrating failure. If faced with this situation, the other (simpler) option is to place a suprapubic catheter via a formal open cys-totomy, and to inspect the bladder as you do so for perforations. Get a urethrogram a few days later. The bladder will often already have been exposed (for fixation of the pelvis). You will know for sure that the bladder is not perforated (and will have repaired it, if it is), and the patients will have adequate drainage of their bladder. Leaving a posterior urethral injury, if present, for subsequent repair is entirely reasonable.
An additional advantage of opening the bladder is that this allows retrograde ureterography to be performed or ureteric stents or catheters to be placed if the ureters have not been adequately visualised on preoperative imaging. Inadequate visualisation of the ureters occurs frequently since in the trauma situation the IVU is often not a complete examination, but is limited to just one or two images, such that the ureter may not be completely opacified. Such limited IVUs will miss a substantial number of ureteric injuries (Presti and Carroll 1996). Indeed, in a series of 50 patients undergoing single-shot intraoperative IVU, the renal collecting system and ureter were not visualised at all in 35% of cases and in only 36% of cases was ureteral detail seen on one or both sides (Morey et al. 1999). In many trauma centres the IVU has been completely replaced by the abdominal and pelvic CT scan, which provides less precise imaging of the ureters than does an IVU or retrograde ureterogram. An abdominal x-ray taken 10 to 15 minutes after administration of contrast for the CT scan can visualise the ureters, but for the same reasons that a limited IVU may not visualise the entire length of the ureter, so too may it be difficult with such an x-ray to confidently exclude a ureteric injury. As for on-table urethrography, performing retrograde ureterography on the operating table is easier said than done in the trauma situation. If in doubt, assume that there might be a ureteric injury and place ureteric stents or catheters.