Vesicoureteric reflux: Viva

Branch 1: Grading and natural history

The candidate should define vesicoureteric reflux as the retrograde flow of urine from the bladder into the ureter and renal pelvis through an incompetent ureterovesical junction. A strong candidate grades this child as grade III on the micturating cystourethrogram, describing the International Reflux Study system from grade I to grade V: grade I is reflux into the ureter only, grade II reaches the pelvis and calyces without dilatation, grade III shows mild dilatation and tortuosity with blunting of the fornices, grade IV shows moderate dilatation with obliterated fornices but preserved papillary impressions, and grade V shows gross dilatation with loss of all papillary impressions. ^[1]

If the examiner presses on the natural history, the candidate should state that the spontaneous resolution rate is proportional to the grade. Low-grade reflux, grades I to II, resolves in up to 80 percent of children over 5 years, and grade III resolves in approximately 50 percent. The resolution occurs because the intramural tunnel lengthens as the bladder grows, which is the anatomical basis of the natural history. The high-grade reflux, grades IV to V, has a much lower resolution rate and is more likely to require surgical correction. ^[1]