Posterolateral thoracotomy incision is still used when thorascopic or laparoscopic approaches are not indicated, even though the general trend in surgery over the last twenty years is toward less invasive surgical approaches.
Indications for Posterolateral Thoracotomy
This posterolateral thoractomy incision is used for gaining surgical access to the structures on the left side of the thoracic (chest) cavity, including the left lung, heart, aorta, the lower esophagus, and diaphragm.
Preoperative Workup and Preparation
Assessment of pulmonary function is mandatory for all patients who undergo posterolateral thoracotomy. This can be accomplished by formal testing in the pulmonary function laboratory or by assessing the ability of a patient to walk up three flights of stairs without stopping.
In posterolateral thoracotomy, patients are typically given a dose of antibiotics preoperatively if they are not already receiving a course for underlying pathology.
Many patients receive preoperative education and incentive spirometry training as to the importance of adequate inspiration postoperatively to prevent atelectasis (lung collapse) that can lead to consolidation (pneumonia.)
The exact placement of the posterolateral thoractomy incision is dependent on the area of the thoracic cavity where the maximum exposure is desired. For best exposure of the upper thoracic area (e.g., for repair of congenital heart defects such as coarctation of the aorta and patent ductus arteriosus) the incision is made at the level of the 5th rib.
For maximum exposure of the left lower thoracic area (e.g., lower esophageal or diaphragmatic surgery), the posterolateral thoracotomy incision is made at the level of the 6th or 7th rib. Although not optimal, if exposure is still problematic, ribs may be transected or in a last case scenario resected.
The operative surgeon performing the posterolateral thoracotomy is positioned to the right of the patient to make the incision. The posterolateral thoracotomy incision is started at point midway between the medial border of the scapula and the thoracic spine. The incision travels parallel to the spine and then curves 3 cm below the tip of the scapula and turns to run parallel with the ribs and extends to the submammary crease.
In cases where the upper thoracic area requires maximum exposure, the incision continues to run parallel to the ribs towards the sternal edge. If lower exposure of the 6th or 7th rib space is desired, the incision is curved into the epigastrium.
Surgical Details of the Procedure
1. The patient is positioned in posterolateral thoracotomy in the right lateral decubitus position (lying on their right side) with the left arm placed above the head on a padded armrest.
2. The lower (right leg) is flexed at the knee with a large pillow placed on it.
3. The upper leg (left leg) is placed on top of the pillow in an extended manner.
4. An axillary roll (rolled sheet or blanket) is placed under the right shoulder to support the shoulder girdle and upper chest wall.
5. In posterolateral thoracotomy, the lower (right) arm is extended and placed on a roll board at 90 degrees to the operating room table.
6. A wide band of adhesive tape is placed over the hips and securely fashioned to each side of the metal frame of the operating room table.
7. The skin incision is made with a No. 10 scalpel as described above.
8. Although some thoracic surgeons in posterolateral thoractomy perform a muslce splitting technique, many surgeons still transect the latissimus dorsi and serratus anterior muscles using the No. 10 scalpel or Bovie cautery.
9. In posterolateral thoractomy, many surgeons elevate these muscles by placing their finger or a large dissecting forceps into the ausculatory triangle formed by an opening in the muscle layer where the latissimus, trapezius, and the medial border of the scapula intersect.
10. Posteriorly, the muscle layers of the rhomboid and trapezius are incised, with care taken to avoid dividing the spinal accessory nerve (which innervates the trapezius) by remaining parallel to the spine.
11. The scapula is then retracted superiorly with firm pressure.
12. The surgeon then reaches under the cut edges of the musles and palpates for the widened intercostal distance of the first intercostal space (between the 1st and 2nd rib.)
13. The surgeon then counts down to the appropriate rib level by moving his hand down the rib cage and palpating for each bony rib protuberance.
14. The pleural space maybe entered by either incising the musculature between the ribs or via an osteotomy through the middle of the desired rib.
15. In the osteotomy technique, a No. 10 blade is used to incise the periosteum in the middle portion of the desired rib.
16. A periosteal elevator is used to raise the sacrospinalis muscle.
17. Coryllos and Hedbloom periosteal elevators are then used to strip the periosteum off the rib in a posterior to anterior fashion.
18. An incision is made through the rib with care taken to confirm that the lung falls away from the chest wall cavity.
19. If the pleural cavity is entered through the intercostal (between the ribs) manner, care must be taken to transect the muscles on the superior border of the ribs to avoid injuring the neurovascular bundle.
20. Care must be taken to identify and carefully ligate the branches of the vascular trunks (usually with 2-0 or 3-0 silk) that run across the posterior intercostal spaces to supply the rib below.
21. Once the thoracic wall has been incised through all layers by one of the two methods described above, the pleural sac is appreciated and open with a fine-tipped scissors.
22. A ratched, self-retaining chest wall retractor such as a Finichetto retractor is then carefully placed between the ribs at the incision site and slowly opened. Care must be taken to avoid causing rib fractures because of a too small incision for the expected area of exposure.
23. After the posterolateral thoracotomy procedure is completed, mechanical drainage tubes must be placed to drain the pleural cavity.
24. Most thoracic surgeons use large diameter (26Fr.) chest tubes placed along the diaphragm and posteriorly for complete thoracic cavity drainage.
25. The stab wounds are made in the skin with a knife in the midaxillary line.
26. The lower cut edges of the serratus anterior and latissimus dorse are retracted superiorly with a Kelly clamp used to make a tunnel from the site of the skin stab wound and into the chest cavity away from the incision.
27. The end of the chest tube is grasped inside of the chest and pulled outward through the just formed tunnel onto the skin.
28. Some surgeons in posterolateral thoracotomy place untied nonabsorbable sutures in a U-stitch fashion that are tied when the tube is removed to close the skin defect.
29. The chest tube is then sutured in place using a large silk suture.
30. The chest tube(s) are then attached to underwater negative suction to promote reexpansion of the lung and to evacuated any acculumating blood or air.
31. After the posterolateral thoracotomy procedure is completed and the chest tubes are placed, the thoracic cavity must be closed in a careful, layered manner.
32. A rib approximator is placed on the superior and medial bone edges of the incision (i.e., on the top and bottom edges of the rib transected in the midline or on the ribs above and below the level of the intercostal incision.)
33. The rib approximator is closed and No.1 chromic or No. 1 vicryl sutures are placed to encircle the bone along the length of the incision. Silk sutures are to be avoided as it increases postoperative pain.
34. Care must be taken to approximate and encircle all rib fragments.
35. The cut rhomboid and serratus anterior muscles are then approximated using interrrupted large sutures such as 1-0 Vicryl.
36. The cut ends of the trapezius and latissimus dorsi muscles are then approximated and sutured together using a large absorbable suture.
37. As the posterolateral thoracotomy incision follows a plane where there is much muscle movement, the subcutaneous tissue is closed using an interrupted 3-0 absorbable sutures.
38. Finally, to complete the posterolateral thoracotomy, the skin is closed using surgical clips or a running 4-0 subcuticular stitch such as Monocryl.