Protecting the Intercostal Nerve at Thoracotomy

Following standard muscle sparing thoracotomy I insert the rib spreader but place one blade under the scapular to allow access to the rib immediately above the thoracotomy incision.
Cautery is used to divide the periosteum over approximately a 5cm length where the upper blade upper retractor will eventually sit.
A sharp periosteal elevator is then used to raise a periosteal flap from the rib inferiorly.
A blunter periosteal elevator is then used to detach the neuro-vascular bundle from the notch on the under surface of the ribs.
Care is taken not to macerate the neurovascular bundle during dissection.
The dissection only needs to be the width of the retractor blade.
The upper blade of the retractor is now inserted directly adjacent to the rib applying no pressure to the intercostal nerve.
A second rib spreader is placed at right angles to retract the muscles.
Three or four pericostal sutures are placed to appose the ribs. The sutures are placed in such a way that the neurovascular bundle is elevated. The lower intercostal nerve is protected by the groove in the rib. Drilling holes in the rib or trying to place the suture between the rib and the nerve proved to have no advantage.