Should micturating cystourethrogram be routinely done for pyeloplasty patients?
Routine performance of micturating cystourethrogram (MCUG) is not necessary for all patients with pelviureteric junction obstruction (PUJO), as the outcome of pyeloplasty appears to be independent of the presence of concomitant vesicoureteral reflux (VUR), suggests a Singapore study.
“[W]e propose that an MCUG should be reserved for those cases with both hydronephrosis and hydroureter on ultrasound scan (US) or history of recurrent urinary tract infection (UTI),” according to researchers.
Pyeloplasty was performed in 119 PUJO patients during the study period and MCUG in 88 patients (74 percent), of whom eight had VUR. These eight patients had unilateral PUJO while two had bilateral VUR. [Proceedings of Singapore Healthcare 2019;28:26-30]
High-grade VUR (grade 4) was found in only two patients, and they also had hydroureter seen on US. Spontaneous resolution of reflux occurred in all patients with VUR. Outcomes for patients with and without VUR showed no statistically significant difference in terms of the need for redo surgery and improvement in differential renal function after pyeloplasty.
“Traditionally MCUG was performed as part of routine work-up for hydronephrosis, but it is not without risk. There is a lower incidence of concomitant VUR with PUJO and also of lesser severity in our population as compared to previously published data,” researchers said.
Previous studies have reported that the coexistence of VUR may compromise the successful management of PUJO, while high-grade VUR may compromise the healing of PUJ anastomosis, potentially leading to stricture and impaired drainage across the anastomosis. [J Urol 1989;142:490-493]
While surgeons have conventionally supported an MCUG to detect VUR as an integral part of preoperative assessment for all PUJO patients undergoing pyeloplasty, performing MCUG has its own snags. One of which is the incidence of post-MCUG UTI, reported to be 7–42 percent without antibiotic prophylaxis and 0–13 with antibiotic prophylaxis. [Lancet 1978;312:1191-1192; Lancet 1979;1:103; J Surg Pak 2010;15:68-72; Pediatr Nephrol 2005;20:1449-1452; Lancet 1976;2:1107-1110]
Other problems associated with MCUG include pain, discomfort from urethral catheterization and cost of the procedure.
“In our study, all patients with concomitant PUJO and VUR had spontaneous resolution of VUR and uncomplicated pyeloplasty surgery. We did not have any secondary PUJO in our study cohort. However, in cases of secondary PUJO due to high-grade reflux, the presence of US-detectable hydroureter is expected to be high,” researchers said.
“As the management for this group of patients would be different, it is important to confirm the diagnosis. Therefore, we propose that only if PUJO is associated with hydroureter or other congenital anomalies of the genitourinary tract, then MCUG should be performed to exclude concomitant high-grade reflux,” they added.
In the present study, researchers conducted a retrospective review of clinical records of all patients who underwent pyeloplasty between 2003 and 2015. Data collected included patient demographics, clinical presentation, radiological procedures performed, operative details and postoperative outcomes.