VUJ calculus causing hydroneprosis

53 year old man presented with left loin pain. He had previous history of passing out stones many times in the last 10 years. Blood test done by his GP showed grossly elevated creatinine level.
Scans of his right kidney showed irregular renal margin and parenchymal thinning. This is consistent with chronic pyelonephritis.

 Scans of his left kidney showed significant scarring in the upper pole and marked parenchymal thinning.

 The left kidney is also hydronephrotic.

There is a 5mm calculus at the left vesico-ureteric junction. This is the cause of left hydronephrosis.
His prostate scans are normal.
It is presumed that his multiple episodes of obstructive uropathy in the past, has led to scaring of both kidneys.