Shaw-Posterior Surgical Technique
Routine measures for lung resection should be undertaken, such as use of preoperative antibiotics, deep vein thrombosis prophylaxis, and a double-lumen endotracheal tube. Central venous line placement is prudent for reliable IV access and central venous pressure monitoring and in most patients should be placed on the contralateral side to keep the line out of the surgical field. Radial arterial pressure monitoring is also recommended and also should be placed on the nonoperative side in case subclavian artery manipulation is required. It is also wise to coordinate surgical scheduling with a spine specialist (neurosurgeon of orthopedic) for backup in case of vertebral body or other neurologic involvement.
After induction of general anesthesia, the patient is intubated with a double-lumen endotracheal tube. The patient is placed in the lateral decubitus position with an axillary roll under the “down” side (Fig. 80-6). The incision begins above the angle of the scapula, halfway between it and the spinous processes (i.e., thoracoplasty technique), and extends inferiorly, angling anteriorly around the tip of the scapula. The subcutaneous tissue is divided, followed by trapezius and rhomboid muscles. Although we generally try to spare the posterior superior serratus muscle, occasionally, this too needs to be divided to allow adequate exposure.
(Inset) Patient positioning and incision. The subcutaneous tissue and trapezius and rhomboid muscles, followed by the posterior superior serratus, are divided.
The intercostal muscle overlying the fourth rib is incised. A Finochietto retractor is placed between the top of the fourth rib and the scapula superiorly. Since double-lumen intubation is used for the operation, the lung is already collapsed. The fourth interspace is opened. Alternatively, this can be done using the cautery. The surgeon places a hand in the patient's chest to palpate the tumor and determine its extent, the number of ribs involved, and the length of each rib to be resected (Fig. 80-7). If the tumor is large, a lower interspace may be used. If possible we generally try to preserve the intercostal muscle flap thus developed, to use for later reinforcement of the airway stump (especially after induction therapy). Anteriorly, the ribs are divided with the rib shears after ligating, dividing, or clipping the neurovascular bundle under each rib. The dissection is carried up to and through the first rib. Posteriorly, the ribs are sheared off with an osteotome, taking the rib at the level of the transverse processes, disarticulating the ribs or taking a small segment of vertebrae, if necessary. The intercostal bundles may be cauterized or clipped. This is carried through the third, second, and first ribs. Patients with CT evidence of tumor invading the vertebrae are generally considered inoperable. However, if at operation the tumor is found to lie adjacent to the vertebrae, a margin of vertebrae is taken with the osteotome. Preparation by involvement of a neurosurgical or orthopedic team may be prudent in this situation.
The intercostal muscle overlying the fourth rib is incised, the fourth interspace is opened, and the tumor is palpated to determine the extent of resection.
After the first rib is cut anteriorly and posteriorly, the surgeon inserts the index finger from one hand in the front and the index finger from the other hand from the back to palpate the tumor (Fig. 80-8) and identify its relationship to the T1 and C8 nerve roots, the lower trunk of the brachial plexus, and the axillary subclavian artery and vein (Fig. 80-9). The scalenus anticus and medius muscles are divided with the finger holding the en bloc section anteriorly and inferiorly. Caution is taken to avoid injury to the artery or vein. The T1 nerve root is divided posteriorly, and the segment is lifted up with the tumor. The C8 nerve root is visualized and may be divided if necessary. The anterior part of the T1 nerve root is divided. The subclavian artery is dissected from the tumor. If the artery is involved, an interposition graft, such as autogenous saphenous vein, is used. This is usually not the case because the adventitia protects the artery from tumor invasion.
After the rib is cut anteriorly, the index fingers are inserted to palpate the tumor.
Using both index fingers as described, the surgeon determines the relationship of the tumor to the T1 and C8 nerve roots, lower trunk of the brachial plexus, and axillary subclavian artery and veins.
A lobectomy optimally is performed after the en bloc chest wall resection. Segmental resection of the lung can considered if the patient is very high risk or no residual tumor is found. In general, these patients have had higher incidence of local recurrences. The chest wall is closed with Marlex if anterior in location. For posterior tumors, however, the scapula covers the posterior area, and usually no chest wall reconstruction is necessary (Fig. 80-10). If the fifth rib is removed, the scapula tip may get hooked under the sixth rib. If it appears that this may be a possibility, the tip of the scapula can be excised (Fig. 80-11). The wound is closed in layers with interrupted 0 Nurolon sutures in a figure-of-eight fashion (Tom Jones stitch), running 2-0 Vicryl in the subcutaneous tissues, and skin clips in the skin.
After en bloc resection of the chest wall, a lobectomy or segmental resection of the lung is performed. With anterior tumor, the chest wall is reconstructed with Marlex. For posterior tumors, the scapula usually overlies the posterior area of the chest wall and reconstruction with Marlex is not required.
If the fifth rib was removed during en bloc chest wall resection and it appears that the tip of the scapula may get hooked under the sixth rib, the tip of the scapula is excised.
Dartevelle Transclavicular Technique
For the anterior approach as described by Dartevelle et al.,41 the patient is positioned supine with the neck hyperextended and turned away from the tumor. A rolled towel behind the shoulders helps with exposure of the operative site.46 The arms can be tucked at the sides, but it may be wise to leave access to the anterolateral chest on the operative side in case an anterolateral thoracotomy is necessary. The patient should be sterilely prepared from the angle of the mandible to below the costal margin and from the midclavicular line of the contralateral chest to the midaxillary line on the side of the tumor and beyond the shoulder superiorly. An L-shaped incision is performed along the anterior border of the sternocleidomastoid muscle, extending horizontally a few centimeters below and parallel to the clavicle into the deltopectoral groove (Fig. 80-12). Depending on the planned area of entry into the thoracic cavity, this transverse incision can be placed over the second, third, or fourth intercostal space.
A. An L-shaped incision is performed along the anterior border of the sternocleidomastoid muscle. Note that the incision is extended horizontally a few centimeters below and parallel to the clavicle into the deltopectoral groove. B. Intraoperative photograph.
The sternal attachments of the sternocleidomastoid muscles are divided, as are the upper digitations of the pectoral muscle on the clavicle; a myocutaneous flap now can be pulled back to expose the thoracic inlet (Figs. 80-13 and 80-14). The medial half of the clavicle is removed (the sternal or Gigli saw works well for this). The omohyoid is divided, if necessary, and the scalene fat pad is removed and checked for metastases. The subclavian vein and its branches, as well as the distal internal jugular vein (depending on the cephalad extent of tumor), are dissected and controlled proximally and distally. On the left it is often necessary to ligate the thoracic duct as it enters the vein. In general, veins should be resected and not reconstructed, realizing that the patient may have edema in that extremity, which can be managed with arm elevation and compression garments. As collaterals develop, the end result is usually not significantly morbid. It can be helpful to divide the anterior, external, and even internal jugular vein to facilitate mobilization and resection of the subclavian vein.
After dividing the sternal attachments of the sternocleidomastoid muscles and upper digitations of the pectoral muscle on the clavicle, the myocutaneous flap created by the incision can be pulled back to expose the thoracic inlet.
Same exposure of the thoracic inlet presented in the intraoperative photograph in Figure 80-12.
The pleural cavity is entered one interspace below the tumor to assess its intrathoracic extent. Next, the anterior scalene muscle can be divided at the first rib, unless it is grossly invaded, in which case it is better to divide it as proximally as possible, taking care to preserve the phrenic nerve (Fig. 80-15). This is followed by dissection of the subclavian artery and its branches, which all can be divided to facilitate mobilization. The exception is that the vertebral artery should be preserved when possible, but if it is invaded by tumor and there is no significant extracranial carotid vascular disease by preoperative duplex study, it should be taken en bloc with the tumor. If it is not possible to free the tumor from the subclavian artery in a subadventitial plane, then preparations should be made to resect and reconstruct it (see below). Next, the middle scalene muscle is taken as high as necessary to better expose the brachial plexus. It may be helpful to have the neurosurgical team assist with neurolysis of the plexus. Nerve roots can be divided but should not be taken higher than C8 (see Fig. 80-15, inset). It is important to ligate the roots to avoid a cerebrospinal fluid leak. If necessary for an R0 resection, the prevertebral muscles along with the paravertebral sympathetic chain and stellate ganglion can be resected safely as well. Many of these patients will have preexisting Horner syndrome, but if not, this possibility should be mentioned when obtaining informed written consent for the operation.
The pleural cavity is entered one interspace below the tumor to assess its intrathoracic extent. Assistance from the neurosurgical team is recommended for neurolysis of the plexus. (Inset) Nerve roots higher than C8 should not be taken.
At this point, the first rib can be divided at the transverse process posteriorly and a few centimeters anterior to the tumor or at the costosternal junction. The second and third ribs also can be resected en bloc with the tumor as needed. This provides an entry point into the pleural space through which the upper lobectomy can be performed. In the past, an accessory anterior or in some cases posterolateral thoracotomy (after repositioning and reprepping the patient) has been made, but with videothoracoscopy assistance, and use of long thoracoscopic instruments and staplers, the additional incisions are less often necessary.
This technique differs from the above-described operation in that the sternoclavicular joint is preserved. The same skin incision is made, and the sternocleidomastoid is mobilized, but the pectoral muscle is split along the fibers a few centimeters below the clavicle rather than separating it from the clavicle (Fig. 80-16). An L-shaped incision is made in the manubrium with the sternal saw to release the upper outer corner adjacent to the sternoclavicular joint. The proximal internal mammary artery is ligated, and the first costal cartilage is resected. Now the clavicle, with attached pectoral and sternocleidomastoid muscles, can be elevated as an “osteomuscular flap” (Fig. 80-17). The remainder of the resection is carried out as described earlier. For closure, the manubrium is reapproximated with two sternal wires. Aesthetic and functional results are reportedly superior to those of claviculectomy owing to preservation of the shoulder girdle architecture. The negative aspects of this technique are again the suboptimal exposure for lung resection and the fact that the vascular dissection deep to the scalene muscles can be more challenging than with the standard Dartevelle incision.46
The clavicle, with attached pectoral and sternocleidomastoid muscles, is elevated as an osteomuscular flap.
Osteomuscular-sparing approach with preservation of the sternoclavicular joint. The pectoral muscle is split along the fibers a few centimeters below the clavicle rather than separating it from the clavicle.
Hemiclamshell or Trapdoor Incision
The hemiclamshell or trapdoor incision (when extended above the clavicle or along the sternocleidomastoid) was proposed originally for trauma to the great vessels or for mediastinal tumors. It provides excellent exposure of the anterior mediastinum and chest apex and has been used with some success for superior sulcus tumors as well. The basic incision consists of a median sternotomy down to the fourth interspace with lateral extension through the intercostals (Fig. 80-18). A standard sternal retractor then may be used to elevate the sternum, or a mammary retractor can be helpful to elevate sternal and intercostal aspects of the incision. Several modifications have been suggested, including extension along the sternocleidomastoid or superior to the clavicle. In this case, the mammary artery should be ligated proximally. Some surgeons recommend resection of the medial clavicle, as in the Dartevelle approach.46 Another alternative is to resect the first costal cartilage and costoclavicular ligament to preserve the architecture of the shoulder girdle while allowing improved mobility of the anterior chest wall and better exposure and control of the distal subclavian vessels.47 The incision is closed by wiring the sternum, reapproximating the intercostal space, and then suturing the pectoral muscles if disturbed during the dissection. A major advantage to this incision is better exposure of the pulmonary hilum. However, the posterior aspect of the thoracic inlet is difficult to dissect with this technique; also, the incision maybe excessive for a smaller, anterior, truly apical tumor.
Hemiclamshell or trapdoor incision provides excellent exposure of the anterior mediastinum and chest apex. Incision consists of a median sternotomy down to the fourth interspace with lateral extension through the intercostals.
Before deciding on the need for vascular resection, the artery should be properly exposed. The vein should be mobilized as described earlier and divided proximal and distal to the tumor if invaded. Next, the artery should be prepared for proximal and distal control by dividing the anterior scalene muscle, preserving the phrenic nerve if not invaded by tumor. The internal mammary artery and ascending cervical artery are divided; the vertebral artery is sacrificed if involved or if the adjacent subclavian artery is involved. In many cases, the tumor can be dissected away from the subclavian artery in the subadventitial plane (Fig. 80-19A). If the media of the artery has been invaded by tumor, steps should be taken for resection (see Fig. 80-19B). Systemic heparinization should be performed, usually with 5000 units of IV heparin. Then the artery can be clamped proximally and distally to permit en bloc resection of the involved portion with the tumor. Reconstruction should be delayed until the rest of the tumor resection is performed. In some cases, it may be helpful to generously wedge the tumor-bearing portion of the upper lobe to be removed with attached ribs and vascular structures so that the vascular reconstruction can be completed immediately, and the heparin then can be reversed. In this way, the completion lobectomy can be performed off heparin. Another option is to give heparin, clamp the artery, complete all the resection en bloc, and then perform the vascular reconstruction, but the vessels will be clamped for a longer period of time.
A. Tumor can be dissected away from the subclavian artery in the subadventitial plane. B. If the media of the artery is invaded, the affected portion is reconstructed.
Reconstruction often can be end-to-end because the distance to traverse is diminished after first rib resection. Otherwise, the material of choice for vascular reconstruction is ringed polytetrafluoroethylene (6 or 8 mm) with end-to-end anastomoses, followed by reversal of heparin with protamine. In the series reported by Fadel et al. 9, the graft length was 1.5 to 4 cm. Shunts were not used. There is no need to place a tissue flap between the vascular graft and the lung. Artery ligation is not an option; if all collaterals are divided during tumor resection and mobilization of the artery, limb ischemia will occur.
Postoperative care is similar to that of any lung resection. With extensive chest wall resection, atelectasis is more common.45 Good postoperative analgesia, adequate pleural drainage, and aggressive pulmonary toilet cannot be overemphasized. Routine mechanical ventilatory support is not necessary. Special attention must be paid to the involved extremity when vascular resection is required, with hourly vascular checks initially. Some surgeons recommend IV heparinization within 4 to 6 hours postoperatively, and then aspirin, once the patient is ambulatory and continued for 6 months postoperatively.46 When concomitant venous ligation is necessary, it can be challenging to assess the perfusion of the extremity, and frequent Doppler checks may be reassuring. Arm elevation and lymphatic massage may help to alleviate edema. Wound healing can be more of a problem when extensive collaterals are ligated along the subclavian artery; diligence for this is encouraged, with aggressive debridement if wound necrosis occurs. When the clavicle has been divided and rewired, an arm sling for stabilization for 4 to 6 weeks postoperatively is recommended.
After arterial resection, follow-up duplex studies should be carried out at 3 and 6 months and annually thereafter. In addition, the blood pressure should be measured in both upper extremities at each follow-up visit. If symptoms of arterial insufficiency occur or duplex study suggests significant stenosis (>80%), angiography is recommended.9 In case of graft occlusion (most often from radiation fibrosis), it may not require intervention in the absence of symptoms. Reported 5-year patency rates are 85%.7