X-ray urethrography characterizes urethral strictures for those patients with urethral stricture disease. As strictures are often impassable by cystoscopy, such studies are necessary to understand stricture length for operative planning. X-ray urethrography can be performed in a retrograde (RUG) fashion or matched with a voiding cystourethrogram (VCUG), which can be particularly informative for visualizing the posterior urethra. While sonography and magnetic resonance imaging are increasingly used, urethrography remains the undisputed preoperative test of choice.

In contrast, the role of urethrogram in the postoperative period is evolving. Urethrography after urethroplasty has traditionally been used to confirm a well-healed anastomosis. The presence of extravasation often results in a clinical decision to increase the duration of catheterization. Of late, there is growing evidence that extravasation is rare after 2–3 weeks of catheterization. This has led some to omit this test altogether in their postoperative urethroplasty pathway. There are existing urological parallels: cystogram is not routinely employed to check the status of the vesicourethral anastomosis after prostatectomy nor is a retrograde pyelogram regularly performed after pyeloplasty.

Figure. Example of post-urethroplasty contrast extravasation 14 days after anastomotic urethroplasty.

Recent evidence from a single center series published by Hoy et al suggests ventral onlay buccal mucosal graft urethroplasty incurs a risk of contrast extravasation of only 3.1%.¹ Likewise, the Trauma and Urologic Reconstructive Network of Surgeons (TURNS) reported (among 1,101 patients treated with varied urethroplasty techniques) an overall extravasation rate of 4.9%.² Specifically for excision and primary anastomosis, there was a 2.3% extravasation rate. Given these findings, one may question the dedication of resources and added stress to the patient in the pursuit of a postoperative urethrogram as a routine enterprise.

Furthermore, in the recent TURNS study postoperative urinary tract infection (12.9% vs 2.7%; p <0.01) and wound infection (7.4% vs 2.6%; p=0.04) were observed more frequently in patients with extravasation vs no extravasation.² One could hypothesize these complications are actually signs of ongoing urine extravasation or poor healing. Such clinical signs may help to identify patients in whom postoperative urethrography may reveal extravasation. Furthermore, patients with longer strictures and complex repairs including grafts were more likely to have extravasation detected. Extravasation on postoperative urethrogram was strongly correlated with anatomical recurrence at 1 year. Of course, the relationship between anatomical recurrence identified on cystoscopy and functional recurrence requiring repeat procedure is yet another controversy. Indeed, another recent retrospective single center series noted extravasation was not predictive for stricture relapse accounting for stricture etiology, location, length and type of surgery in multivariate analysis among 630 patients (HR: 1.57; 95% CI: 0.8–3, p=0.173).³

One criticism of available studies is a question of heterogeneous techniques: pull-back RUG, peri-catheter RUG, or VCUG are all options after catheter removal. Over pressurization may reveal extravasation that would not otherwise be present with physiological voiding pressures. Under pressurization may lead to false-negative results. The inter-observer agreement for performing and interpreting these studies is unknown. There also is likely a difference between a wisp of extravasation and a completely failed anastomosis in terms of management and pathophysiology. Grossgold et al, in grading the extent of extravasation, identified that increased extravasation length and width appeared to predict anatomical recurrence.⁴

There are additional arguments that favor continued postoperative urethrogram. The available literature summarizes surgical results among expert surgeons. The steep learning curve for urethral stricture treatment is well characterized. One may hypothesize increased extravasation rates for surgeons with less experience. Such information provides tangible feedback for the surgeon. Consistent followup after urethroplasty remains a challenge. In the TURNS protocol, for instance, less than 50% of patients return for cystoscopy. Therefore, the RUG/VCUG potentially represents an opportunity for a surgeon to collect objective feedback. Moreover, there is psychological benefit for nervous patients (and surgeons) knowing the repair has healed in a watertight fashion that in some cases supersedes anxieties about the test itself.

Like most things in life, the best approach may require nuance. For more complex surgery, in particular long urethral repairs employing grafts, postoperative urethrogram may help drive postoperative decision making. Early career surgeons should likely rely more heavily on postoperative urethrogram to guide catheter management as well as serve as a quality control check. On the other hand, for straightforward cases postoperative imaging may be omitted at the discretion of an experienced surgeon. If extravasation is noted, given the potential increased risk of anatomical recurrence, more stringent surveillance should be encouraged.