How do you manage a patient who has a persistent urine leak after partial nephrectomy six weeks or more after drain and stent placement?

The stent is fine, but I would add a Foley catheter too for the next two weeks to see if the drainage decreases. Also, pull the drain back 2 cm, as sometimes it will actually keep the fistula open. If, with the drain pulled back, the stent is in the proper position (i.e., definitely in the renal pelvis or upper pole of the kidney - away from the fistulous tract) and with the Foley in place, the drainage does not decrease over 2 weeks, then there are other options before one would need to go and ...

Get a CTU to ensure that the stent is in a good position, that there is no excluded calyx, and that the tip of the drain is in a good position. If okay, continue observation with a Foley catheter.