Re-approximating the divided diaphragm after a left thoracoabdominal incision is not that easy. Running or interrupting suturing?
Interrupting sutures are the best option. Use a number 2 absorbable suture and start from the most posterior end as long as the chest wound is still opened. Prefer horizontal matress suturing starting from the abdominal cavity. This way the knots will not be on the chest cavity.
Carry on suturing until 3-4 stitches are still needed to complete the closure. Put the last sutures as previously described but avoid tying them. Let them loose hanging with a hemostatic clip on each one.
At this stage, close the ribs with isolated heavy absorbable sutures (number 2), and after the chest ribs are approximated tie all the loosing sutures.