Pros and Cons of Anterior and Posterior Approaches to Pancoast Tumors: Posterolateral Superior Sulcus Tumor Resections

Chest radiograph and CT scan of right superior sulcus tumor. This chest radiograph shows a right-sided superior sulcus tumor (A). Unless large, they are often missed, obscured by the clavicle and first rib. The preoperative CT (B) demonstrates invasion of the chest wall and first rib, and it appears to involve the great vessels. This patient, like most patients with extensive Pancoast tumors, received neoadjuvant therapy. It is important to re-image these patients before surgery (C).

Tumor invading brachial plexus. The ideal tumor for the posterolateral approach is situated posterior in the superior sulcus and does not invade the anterior structures of the thoracic inlet. It may, however, invade the vertebral bodies, or with regard to the thoracic inlet structures, the brachial plexus. The C8 and T1 nerve roots are most commonly invaded. It is important to assess the patient’s neurologic function preoperatively and to counsel the patient on the potential neurological postoperative morbidity.

Incision. The patient is in the lateral decubitus position. A posterolateral thoracotomy incision is made extending from the anterior axillary line around the scapula to the base of the neck. Note the transected trapezius, latissimus dorsi, and rhomboids. The dorsal scapular nerve and scapular artery branches should be avoided when dividing the rhomboids at their insertion to the medial border of the scapula. These muscles will all be meticulously reapproximated at the end of the case. (Figure adapted from Nesbitt JC, Wind GG, Rusch VW (consulting ed.), Walsh GL (consulting ed.): Superior Sulcus Tumor Resection in Nesbitt JC, Wind GG (eds.): Thoracic surgical oncology: Exposures and techniques. Philadelphia, Lippincott Williams & Wilkins, 2003; p 162-193, with permission.¹²)

Thoracotomy. A thoracotomy is made in the fourth intercostal space. In the case of a smaller tumor, the thoracotomy can be made below the third rib. However, it is important to be at least one rib space below the tumor for adequate margins. The surgeon palpates the tumor before extending the thoracotomy. Next, the surgeon proceeds to divide the serratus anterior from the uppermost ribs. This permits the scapula’s elevation off of the chest wall. Figure 4 demonstrates the scapula being elevated with the superior retractor blade underneath the scapula and the inferior blade in the thoracotomy. (Figure adapted from Nesbitt JC, Wind GG, Rusch VW (consulting ed.), Walsh GL (consulting ed.): Superior Sulcus Tumor Resection in Nesbitt JC, Wind GG (eds.): Thoracic surgical oncology: Exposures and techniques. Philadelphia, Lippincott Williams & Wilkins, 2003; p 162-193, with permission.¹²)

Division of scalenes. After the scapula has been elevated, attention is directed toward the scalenes. Dividing the scalenes exposes the structures of the thoracic inlet. Note the insertions of the anterior and middle scalene on the first rib. Also of note is the phrenic nerve lying on the anterior surface of the anterior scalene. This, as well as the subclavian vein and artery, should be identified before dividing the anterior scalene. (Figure adapted from Nesbitt JC, Wind GG, Rusch VW (consulting ed.), Walsh GL (consulting ed.): Superior Sulcus Tumor Resection in Nesbitt JC, Wind GG (eds.): Thoracic surgical oncology: Exposures and techniques. Philadelphia, Lippincott Williams & Wilkins, 2003; p 162-193, with permission.¹²)

Anterior division of ribs. Once the first rib is adequately exposed, the lower trunk of the brachial plexus is apparent as well. At this point, we proceed to divide the ribs with shears anteriorly in this order: fourth rib, third rib, second rib. The neurovascular bundles are ligated and divided anteriorly, as well.

Right upper lobectomy. Once the anterior division of the fourth through second ribs is accomplished, a standard right upper lobectomy is performed. A wedge resection is an option but is not recommended.¹ A standard mediastinal lymph node dissection should be done at this point.

Division of first rib. The anterior division of the first rib is accomplished using a Gigli saw after carefully dissecting around the rib with a right-angled clamp. The subclavian vessels may be gently retracted with a soft-tipped clamp before dividing the rib. Another option to protect the vessels is to lay a ribbon “retractor” on the vessels, placing the ribbon between the vessels and the Gigli saw. If the space around the artery is violated, it is easy to notice the saw grinding against the ribbon before any damage should occur.

Assesment of C8 and T1 nerve roots. With all four ribs divided anteriorly, and the lobectomy done, attention is directed toward the tumor’s involvement with the brachial plexus. At this point, the tumor is still fixed posteriorly. The C8 and T1 nerve roots are apparent. Even if involved with tumor, every effort should be made to spare the C8 nerve root to avoid the morbidity of loss of function of the intrinsic muscles of the hand. When the T1 nerve root is divided, there is usually only a sensory deficit along the medial aspect of the hand.

Posterior division of ribs. The ribs are divided posteriorly next. First, the paravertebral muscles are divided exposing the spine. The ribs are divided from inferior to superior with an osteotome at the costotransverse junction. When the osteotome pops into the costotransverse junction, this leverage exposes the neurovascular bundle for ligation. It is extremely important to ligate the neurovascular bundles. Potential complications include tension pneumocephalus, cerebrospinal fluid leak, or a progressive hematoma causing spinal compression. If there is bleeding, temporary packing can be placed but must be removed during the procedure to prevent embolism. (Figure adapted from Nesbitt JC, Wind GG, Rusch VW (consulting ed.), Walsh GL (consulting ed.): Superior Sulcus Tumor Resection in Nesbitt JC, Wind GG (eds.): Thoracic surgical oncology: Exposures and techniques. Philadelphia, Lippincott Williams & Wilkins, 2003; p 162-193, with permission.¹²)

Vertebral body articulation. If the transverse process is involved with tumor, rather than division at the costotransverse junction (A), the rib should be divided as in (B). (Figure adapted from Nesbitt JC, Wind GG, Rusch VW (consulting ed.), Walsh GL (consulting ed.): Superior Sulcus Tumor Resection in Nesbitt JC, Wind GG (eds.): Thoracic surgical oncology: Exposures and techniques. Philadelphia, Lippincott Williams & Wilkins, 2003; p 162-193, with permission.¹²)

Closure of defect. Once the ribs have been divided posteriorly, the tumor (still attached to the chest wall) is removed as one specimen. At this point, a routine evaluation of the margins is done, obtaining biopsies and placing clips to direct postoperative radiation. The divided muscles seen in Figure 3 must be reapproximated. Chest tubes are placed. A defect of three or more ribs, or a defect over the tip of the scapula, should be closed with synthetic mesh (eg, Gore-Tex®). Superiorly, the mesh is sewn to the scalenes and fascia surrounding the clavicle. Anteriorly, it is sewn to the intercostal fascia and muscle and around the cut rib ends. Posteriorly, it is sewn to the paraspinous muscles and fascia. Inferiorly it is sewn around (pericostal) the intact rib. Meticulous reapproximation and closure with mesh prevents major morbidity in respiratory chest wall motion.