Abstract
I
The authors also claim that intraoperative detection of ureteral duplication through endoscopy and fluoroscopy in patients without a prior diagnosis by means of imaging modalities is sufficient and does not affect surgical outcomes.
Talking of preoperative imaging work-up, we can speculate whether an enhanced abdominal CT before retrograde stone endoscopic treatment (implying preliminary identification of ureteral duplication if present) would have been essential or simply useful. Probably it is not essential, assuming that ureteral duplication is not accidentally overlooked, since according to the present study, this knowledge seems to have no evident impact on ureteroscopic outcomes, whereas the lacking execution of this kind of imaging additionally spares X-ray exposure to the patient and healthcare system costs.
On the other hand, EAU guidelines on urolithiasis 4 recommend a contrast study if stone removal is planned and the anatomy of the collecting system needs to be assessed with a Grade of Recommendation A based on a Level of Evidence 3. Following these suggestions, the preoperative diagnosis of ureteral duplication might prove to be useful for a number of reasons.
In the era of tailored therapies and personalized treatments, the urologist could inform the patient about this congenital anomaly, especially about its possible implications on the planned surgery. In fact, duplicated ureters have a particular anatomic arrangement and a smaller caliber, 2,5 therefore getting ureteral access might be more demanding, with the possible need of presenting for passive dilation, enhancing ureteral compliance to both ureteral access sheath and retrograde ureteroscope. 6 To avoid complications and instead of a two-step retrograde endoscopy, miniaturized percutaneous access may become an option, especially in those cases where high intrarenal pressures and related uroseptic risk should be absolutely avoided (like in diabetic patients or in case of infectious stones). 7,8
Consequently, an adequate endoscopic armamentarium (including pediatric and miniaturized endoscopes for both retrograde and antegrade access and small-caliber accessories) could be set up in advance, with the aim to adapt the instruments to the patients, and not vice versa, 9 and to respect the particular anatomy of their collecting system. The authors work in a high-volume, tertiary referral center, therefore they may not have this problem, but when extending their conclusions to the daily clinical practice in smaller urologic centers, this issue might become relevant.
In the era of preventive medicine, we could also consider that ureteral duplication—although often asymptomatic 2,3 —might be associated with other congenital anomalies 2,5 and produce stasis of urine, causing urinary tract infections and urolithiasis, especially in the complete and bilateral forms. The timely identification of such an anatomic variant would allow patients to undergo regular follow-up examinations (urinalysis, urine culture, and ultrasound examination) to prevent recurrent urinary tract infections with possible secondary pyelonephritis and/or the formation of large stone burdens. 10
In conclusion, preoperative detection of ureteral duplication by means of enhanced CT is not necessary and does not affect ureteroscopic outcomes. All the same, the preoperative assessment of the anatomy of the collecting system containing the stone is always useful to tailor both surgical treatment and future follow-up based on the patient's features.