Moving a shunt

I was diagnosed with normal pressure hydrocephalus at three months of age. My brain hemorrhaged on the right side and I was given a VP shunt. I had five revisions up until 2009, when the shunt clogged up again. The surgeon who operated on me, at the time, was not my regular doctor. After the 90 minute operation, I was sent home and later complained about having severe headaches and nausea. I returned to the hospital and the CT scans showed nothing was and I was thus, sent home again. This pain continued for a year and ten months and on Feb 16, 2011, my shunt stopped working again. During this time, I found a new doctor and changed hospitals. My new doctor that the previous surgeon who operated on me ( 2009 ) had moved the shunt from the right side to the left and re-routed it through the right. Why would he have done this? My new doctor then replaced the valve, placing it on the right side (where it was supposed to be) and also gave me a new ventricular catheter. He couldn't understand why the other doctor had moved the shunt to the left side in the first place. What are some reasons a surgeon would do this?