Thoracotomy may be described as posterior, postero-lateral, lateral, anterolateral and anterior.
The patient is positioned on their contralateral side ensuring that
the arm is flexed at the shoulder, drawing the scapula up
the trunk is ‘broken’ at the subcostal margin with a sandbag and bent table.
the knee and ankles are protected with jellybags to prevent injury to the common peroneal nerve
Find the tip of the scapula by sliding the scapula down to abut the fingers of the opposite hand.
Find the midway point between the medial border of the scapula and the vertebral column. Join the two points in a curving line parallel to the circumference of the ribs, flowing inferiorly as the incision becomes more anterior. This is the skin incision. Avoid going deeper than the skin with the scalpel to minimise bleeding.
Latissimus dorsi (lat dorsi) is cut anteriorly, revealing serratus anterior deep to it.
Trapezius is encountered posteriorly. Further posterior are the erector spinae and the spinal ligaments.
Undermine the muscles to create a flap for closure later on.
Once the ribs are seen, slide the hand between the scapula and the ribcage. Count the rib spaces from the 1st rib. The posterior scale muscle can be encountered attaching to the 1st and 2nd ribs.
The periosteum is incised using the diathermy in the centre. Feel the boundaries of the rib to accurately estimate the centre as the fascia and muscles can obfuscate it.
The periosteal elevator is used to lift off the periosteum and the muscle superiorly over the rib. Its tip is inserted into the freed space and dragged along the superior border of the rib to free the intercostal muscles, thus entering the pleural cavity.