The commonest cause for moality in Iver levis operations -
Ivor Lewis operation - is subtotal esophagectomy done for Ca esophagus in the lower third of esophagus. Pa of stomach and esophagus are resected and remnants of both anastomosed. Anastomotic leak is the most logical answer. I have also confirmed it from Senior residents of surgery. Ref : Bailey & love, 25/e p1033
Pulmonary atelectasis
Anastomotic leak
Thoracic duct fistula
Subdiaphragmatic collection
G.I.T