Multi-level surgeries are a thing. What they are is you have a 15 step 30 hour surgery you need to do. You do steps 1-8 for x hours sew up or cover up, rest for several hours for both the surgeon and the patient, then complete steps 9-15 at a later date.

10-15 hour surgeries are relatively common but 36 hour surgeries are nearly never done all at once unless the patient will die very soon without the surgery and they cannot afford a few hours of rest. Most likely in that situation they would have an extremely high likelihood of death during the surgery so most times these surgeries would never be done and family wishes talks come into play.

Usually traumas get the special service of repeated surgeries with long total operative time with ALSO an extremely high risk of death within the next few hours that would prevent taking breaks. But even then patients can be stabilized long enough to take breaks, breaks for the patient are usually more important than breaks for the surgeon.