Patients coming out from the OR following a thoracotomy for either wedge resection or lobectomy usually have 2 chest tubes placed. They are both pleural tubes. One is positioned posteriorly and curved toward the base of the lung for drainage of blood that collect in the dependent lung area. The second one is positioned anteriorly toward the lung apex for evacuation of air that have been introduced during the surgery.
These tubes usually meet via a Y-connector that is attached to a pleur-evac system. The surgeons where I work have different preferences as far as applying wall suction to the pleur-evac. Two of them keep suction applied the night following surgery and then places the pleur-evac to water seal the next day if there is no air leak. The other one leaves the pleur-evac on water seal immediately post-op.
After surgery, the affected lung usually compensates by filling up the space where the tissue was removed by shifting of the mediastinum, elevation of hemidiaphragm, and narrowing of intercostal spaces on the affected side. However, there are instances when a pneumothorax persists after surgery. I would suppose the surgeon would prefer to keep the pleur-evac on suction if this is the case to facilitate emptying of that air. However, if the size of the air-filled space is not considerably large, no further surgical intervention is needed as this should resolve in time.