Can we travel abroad the US on a B2 visa for medical reasons?

We've been living in the US for 5 years on a L1 and L2. Our visa is due on January 31, 2017. Our will is to return to Europe as soon as possible. However, I was diagnosed with breast cancer in February 2015 and that's been a long winding road with 6 surgeries so far and scheduled for number 7 in February 2017. It's our priority that the next and hopefully last surgery is performed by the same doctor here in the US. Therefore, we're willing to apply for a change of status to convert our L1 visa into a B2 visa. We're quite confident that we'll be granted with the visa and can stay in US until I'm fully recovered and healthy again. The whole process could take between 3 to 6 months. The problem is that today we had a meeting with an immigration lawyer and according to her we're not allowed to travel outside the US and have granted the reentry while we're with a visa B2. My husband is actively looking for a job in Europe and he'll potentially have to travel two or three times if he's asked for an interview in person. What if he's not allowed to entry the country? I'd really appreciate some advice in here. Thanks in advance!