Student or Learner
I am not sure exactly where the commas go in this sentence.
The right kidney and left kidney measures 10.0 cm in length respectively without hydronephrosis or stones.
The right kidney and left kidney (both) measure 10.0 cm in length without hydronephrosis or stones.
There is no need for a comma in this sentence. However, you are referring to two organs, so the verb is plural. Moreover, the organs are the same length. "Respectively" is used in the following way: The right kidney and left kidney measure 10.0 cm and 11 cm in length respectively ...", that is, it refers the order in which I give the lengths of the organs back to the names of the organs in the same order as written.