ptt level high with clearance?

i went to a hematologist and they did so many test my ptt level was 46 but everything else is normalshe said there is nothing wrong with my lab work except my ptt level she can't find anything that can be causing it she wrote down a clearance letter for my surgeon should i listen to my hematologist or should i just cancel my surgery even tho I'm cleared .. my labs where normal back in may last year i couldn't get surgery due to a personal issue .. now its high with no explanation.