Vanquish with one kidney.
Since you do have metal clamps near your kidney, it would be safest to contact the manufacturer, BTL, and ask them if Vanquish would be safe for your special medical condition.
Vanquish Safe with only one kidney
Vanquish can safely be performed on patients with only one kidney. The primary contraindication for treatment with Vanquish is the presence of metal implant or metal device, including a pacemaker or defibrillator. While Vanquish does rely on the excretory system, the procedure should not put undue stress on your remaining kidney. Of course, it is vital to make your provider aware of your condition and surgical history. Best of luck with your treatments!
Unless you have a permamently inserted metallic object close to the areas to be treated, there would not be a problem using Vanquish. you can go ahead and have the treatment safely if you only have one functioning kidney.