My 93 Year Old Mother Just Had An Out-patient Procedure

My 93 year old mother just had an out-patient procedure for a biopsy of a tumor found on her ureter tube. The result came back as non-diagnostic due to the lack of tissue for testing. Now the doctor wants to put her back in the hospital to do the same procedure again and try to gather a larger sample of tissue for testing. Now, I'm beginning to question the doctors proficiency.