What have you been doing for activity? Walking, sitting, etc.
Seems like gravity must be involved so avoiding standing might help. Maybe he even elevating your hips to get the fluid to drain back out of the canal.
My reading implies that aspiration raises the risk of infection. The surgeon will want to wait a long time to avoid that possibility.
Can you give some details of the situation? Type of hernia, repair material, etc. Not clear why a lymph node would be removed. Good luck.