Impact of F1 visa on L1A visa while on sabbatical from employer

I have been working in the United States for almost 5 years and have an approved L1A petition for 2.5 years. I recently (1 month ago) have travelled overseas for personal reasons. I have been accepted to a one year full time program in the US, for which I will need to get a F1 visa. I cannot maintain my L1A status due to the course workload.
My question:
I will be going on a sabbatical from my employer and rejoin after completing the program. What will be the impact on my L1A visa? Will it be cancelled? I do not want to go through the H1B lottery system after completing my course

Thanks in advance for your advice!

After you complete your F-1 program, your employer can file L-1A for you and you can avail the remaining term of L-1 (7 years minus time already spent inside US on L-1 and H-1).