Can someone travel on B1 visa after Middle name removed from renewed Passport

My father has removed his middle name from his new passport(removed kumar. Why he has done it is because all his other documents except 10th MarkSheet not having middle name). He has both B1 visa and old passport with his middle name(middle name kumar). Can he travel with his existing B1 visa to US? He got his affidavit saying old name(with middle name) and new name(without middle name). I am waiting for this query to get resolved so that they can travel next month. Thanks for your help!