Any type of surgery has risks and the potential for complications afterwards. Sometimes adverse events occur during the procedure while others are postoperative. Some postoperative problems occur immediately. Others don’t crop up for weeks, months, or even a year or two.
Because of liability, surgeons must inform all patients of all potential risks — even if these are unlikely to happen. Some patients have certain risk factors that can increase the chances of something unfortunate happening. For example, with spinal surgery, we know that older age (65 and older) is a red flag risk factor. So is an extensive (invasive) spinal procedure.
Surgeons are usually very careful in their patient selection. They want the patients to have a successful outcome. That’s why assessing and discussing risks for complications is an important part of the pre-operative work up. The decision to have surgery, the type of surgery, and the invasiveness of the procedure can be influenced in part by considering potential complications.
Your mother’s decision to cancel her surgery may really be the best thing right now — either based on what the surgeon told her, her own gut feelings, or both. This may be just a postponement for now. She can always reschedule the procedure at a later time if further information reveals less risk for her than she thought.