A 50-year-old male is admitted with acute renal failure. He has type 2 diabetes and chronic kidney disease and hypertension. Although IV hydration is performed, BUN and creatinine do not return to normal. The physician performs a nephrotomy with exploration, which reveals ureteropelvic junction obstruction. The physician proceeds with renal endoscopy through nephrostomy with ureteropyelography, ureteral catheterization, injection of contrast, insertion of a stent, and biopsy of the left kidney. Which codes should be assigned?