What Causes Fluctuating Creatinine Level And Slight Blood In Urine After Nephrectomy?

In June 2013 I had a partial nephrectomy of my right kidney due to a cancerous cyst.The surgeon took out the cyst and approx. 15% of the kidney. The biopsy showed that the walls of the cyst and the part of the kidney that was removed were clear and no cancer cells were found. After the surgery my Creatinine level started to go up and went up to 204 and then it started to come back down to 167 where it is today. There is also some microscopic blood in the urine. I was sent to a Nephrologist who has given me numerous blood test, a ultrasound, a cystoscopy, a kidney biopsy and a 24 hour urine test. They have found nothing that would cause this condition. ( No protein in urine.) My surgeon said I would have blood in my urine for 2 years or more due to the surgery but my Nephrologist disagrees, I also read that after a partial kidney removal the creatinine level could go up and then go down levelling off between 141 – 159 which he also disagrees with. I have an appointment with him again on Feb 11 and he said if the Creatinine level hasn’t gone down I would have to start a 6 month treatment of high dosage prednisone. I do not want to do this as the side effects of prednisone are terrible. I would really like to get a second opinion due to the difference of opinions I am getting from my doctors.Thank you.