Diagnosing and treating occult vesicoureteric reflux using PIC cystography: Is it influenced by abnormalities on DMSA?

Background: Positioning the Instillation of Contrast cystography (PICc) is used to identify occult vesicoureteric reflux (VUR) in patients with recurrent urinary tract infections (UTI) despite optimized bladder and bowel function and without VUR demonstrated on conventional imaging.

Aim: To determine the incidence of finding occult VUR in such patients usingPICc and the benefit, if any, of treating it. We also assessed if this was influenced by abnormalities on the pre-operative DMSA.

Patients And Methods: This was a retrospective review of PICc in our hospital between 2016 and 2018 and involved three paediatric urologists. The primary indication for PICc was two or more culture proven UTIs despite optimized bladder and bowel function and no reflux on voiding cystourethrography (VCUG) or indirect radionuclide cystography (I-RNC). All children had a preoperative DMSA scan to document any abnormalities. PICc was performed in a standardized way to each ureteric orifice. If occult reflux was found, it was treated concomitantly by cystoscopic injection of Deflux®. To assess the influence of the pre-operative DMSA status, the cohort was subdivided into two groups based on the DMSA scan: Group 1-abnormal DMSA, Group 2-normal DMSA. The median follow-up was 26 months (range 3-39 months).

Results: PICc was performed in 25 patients [23 females and 2 males; median age: 7 years (range 2-16 years; IQR = 4)]; 17 from Group 1 and 8 from Group 2. Occult VUR was identified in 22 patients (88%); 15/17 (88.2%) in Group 1 and 7/8 (87.5%) in Group 2 (p = 0.9). After cystoscopic treatment, 21/25 (84%) became infection free and this was not influenced by the preoperative DMSA status (p = 0.6). Fig 1.

Discussion: In this challenging group of patients, looking for and treating occult reflux appears to be clinically useful and beneficial. The ability to test and treat at the same sitting is an added advantage of PICc. The DMSA results did not influence the diagnostic or therapeutic aspect of the process. Our results concur with other published literature.

Conclusion: There is a high incidence of finding occult reflux using PICc in this cohort of patients. Concomitant cystoscopic treatment led to 84% of children becoming infection free on follow up. Abnormalities on DMSA did not influence either the likelihood of finding occult reflux or the likelihood of successful treatment.