Apparently your patient has disease confined to the oesophagus; surgery is
the only possibility to cure her.
The spirometry data do not seem too bad and are , in fact, what you can
expect in a heavy smoker (most patients with esoph cancer, in our
experience). What we would do in a fragile patient like this is admit her 2
weeks before surgery and start a regimen of parenteral nutrition and
intensive chest physiotherapy. The most appropriate procedure would be, in
my opinion, the Akyama operation. I do not suppose that the position of the
stomach conduit (mediastinal or retrosternal) has much influence on
respiratory complications. Postoperative early enteral feeding (needle
jejunostomy) seems to be beneficial.