I have to agree with Jo and Di.. In my opinion less is best in the beginning.. We never know what the future holds..

My TOS was Neurogenic and Vascular. I had the scalenectomy. A Section of the Anterior and Middle Scalene muscles and neuroplasty of the brachial plexus, long thoracic nerve, ulnar and axillary nerve's. I had a supraclavicular approach and Transaxillary approach. It will be a year ago on the 23rd of this month.
I will be going back into the OR with Dr Filler to have redeveloping adhesions removed from my first TOS surgery on the 24th.
I have heard of other scaleneectomys as well as rib resections redeveloping adhesions down the road.

There have been other members on the board that have had sever vascular and arterial TOS etc. and have had surgery very similar to mine and didn't have a rib resection and are doing well to this date.. But then everyones situation is differant and requires differant interventions..
I'm sure you and your Dr will make the right decision for you when your surgery date nears.

Do you have Dr Sander's Book- Thoracic Outlet Syndrome "A Common Sequela of Neck Injuries” It is a great book, A little pricey.. I believe I paid $80.00 plus postage for it.. I ordered it from his office and it arrive a day or two later.. It will answer so many of your questions..

I wish you the best of luck. What ever your decision is I pray that you have a positive outcome and an uneventful recovery..

Keep us posted..

((Many Gentle Hugs))
Dawn