71: The Five Lobectomies

The ability to select patients appropriately, perform a competent pulmonary lobectomy, and manage patients safely in the postoperative interval epitomizes the skills of a good general thoracic surgeon, more than any other aspect of the job. Lung cancer patients comprise a majority of general thoracic surgical patients, and lobectomy, particularly the extended versions (i.e., sleeve lobectomy and lung and chest wall resection), constitutes most of a general thoracic surgeon's work. In no other endeavor does a thoracic surgeon have more impact on his or her patients.

However, the frequency with which an operation is performed often does not mean that it is well performed. A recent evaluation of the National Cancer Database revealed that many or most lobectomies in the United States were done without checking surgical margins or performing mediastinal lymph node dissections despite extensive evidence that these actions are important for long-term survival after cancer resections.¹

The reason for this lack of uniformity is not entirely clear but it is probably that many surgeons, both general and cardiac, regard general thoracic surgery as a secondary rather than primary occupation.² Whatever the reasons, appropriate performance of this common but potentially dangerous operation is important for our patients.

Lobectomies can be done in many different ways, but the sites of danger usually remain the same. In fact, a surgeon may choose an unusual approach because it lessens the chance of problems for a particular patient compared with the standard approach.

Staging

Preresection staging should be done for all patients undergoing lung resection. At this time, a complete history and physical examination focusing on involvement of lymph nodes and liver masses, followed by chest CT scan and PET scan, are appropriate. The latter evaluation will rule out distant metastases other than brain metastases. Patients without symptoms of headache are unlikely to have brain metastases, and therefore, head CT scan or MRI is not obligatory.

All patients with lung cancer may have mediastinal metastases. Although PET scans are quite sensitive for identifying mediastinal metastases, they remain less accurate than mediastinoscopy (see Chapter 70). Preoperative mediastinoscopy is indicated for all patients with a PET scan-positive mediastinum and should be considered for certain patients with a PET scan-negative mediastinum (i.e., those with enlarged nodes on CT scan or with hilar lesions). Although the PET scan remains useful for ruling out distant metastases, it should not be the only study performed to evaluate the mediastinum. Many patients have been denied resection because their PET scan was positive in the mediastinum, only to find a more knowledgeable physician who, on mediastinoscopy, diagnosed mediastinal granulomatous disease instead and then successfully resected the patient's stage I cancer (Table 71-1).

Thoracoscopic examination and staging of the pleural space benefit patients undergoing lung resection³: Thoracoscopy may identify pleural metastases. Thoracoscopy can be used to determine a suitable incision for resection. Thoracoscopy is not indicated for all patients undergoing routine resection of an apparent stage I cancer but can be used to evaluate small pleural effusions or large cancers believed to be unresectable as a consequence of mediastinal invasion (Table 71-2).

Cardiopulmonary Evaluation (or Minimizing Preoperative Risk)

Immediate perioperative mortality (i.e., death within 2–5 days) is very rare after a lung resection. Most deaths occur within the first week. Postoperative mortality in lung resection patients results mostly from respiratory complications. Predicting perioperative mortality in lung resections relies on identifying those patients who

• might have a perioperative complication and

• might not survive it

Our literature has dealt with this problem primarily by focusing on preoperative lung function or predicted postoperative lung function as a means of identifying patients who would not survive a respiratory complication (Table 71-3).

Right Upper Lobectomy

Viewed from the patient's side, the anatomy of the right hilum is a triangle with the pulmonary artery (PA) at the apex, the vein anterior, and the bronchus posterior (Fig. 71-1A). The azygos vein caps the triangle. It is often adhesed to the bronchus, the artery, or both and can be divided as a first step to gain proximal control of the PA and to perform the paratracheal lymphadenectomy.

Harvesting the mediastinal nodes is an important part of the procedure and can give more proximal exposure to the PA and bronchus, if needed, and is a good first step. The nodes are resected by dividing the azygos vein and harvesting the nodal packet (typically 3 × 1.5 × 1.5 cm) and by, in turn, dividing the mediastinal pleura posterior to the superior vena cava and anterior to the trachea. The nodes extend inferiorly to the PA and superiorly all the way to the subclavian artery at the thoracic inlet (Fig. 71-1B). However, overly aggressive manipulation in this area can lead to right true vocal cord paralysis. Consequently, the dissection should stop well inferior of the subclavian artery (Table 71-4).

Although many ascribe importance to the order of division of the hilar structures, there are no studies to confirm either a technologic or an oncologic benefit to a particular sequence. In any case, a small benefit would be superseded by a surgical mishap. Consequently, many do what is most appropriate for the particular patient (usually this means whichever is easiest). My preference is to divide the PA first, then the vein, then the bronchus, and finally the parenchyma, unless the artery is covered by the vein, in which case the vein, then artery, then bronchus are divided in that order. In both cases, the parenchyma is divided last to prevent air leaks.

The hilum is first approached by dividing the parietal pleura around the hilum, being careful to avoid the phrenic nerve, which should be swept medially. If the superior vein covers the PA anteriorly, the vein is approached and the middle lobe vein identified and preserved (Fig. 71-2). The vein then may be divided with a stapling device or with ligatures and suture ligatures proximally and distally. Pulmonary vessels should be controlled with two sutures proximally (e.g., either two ties or a tie and suture ligature) or a stapling device (e.g., gray, red, or white). Single ties or suture ligatures are not adequate. Small branches can be doubly clipped (Table 71-5).

After dividing the upper lobe branch of the superior vein and the main upper lobe PA (which may be present as two or three branches), a single small, more inferior branch of the ongoing PA usually ascends superiorly to the upper lobe (Fig. 71-3). This artery must be controlled and divided to complete the upper lobectomy, and often this can be the most challenging part of the procedure. Sometimes the vessel can be identified from the anterior aspect of the dissection, after the main arterial branch to the upper lobe has been divided. Otherwise, it is at risk when the bronchus is dissected and can be identified in the crotch between the takeoff of the right upper lobe bronchus. It should be divided before dissection and division of the bronchus. Small clips are recommended (Table 71-6), but may be avulsed if the parenchyma is subsequently divided with stapling devices. More recent experience demonstrates that an energy device (specifically Ligasure) safely divides the small vessel.

Developing the plane between the bronchus and the artery is the most dangerous part of a right upper lobectomy. Granulomatous disease, preoperative chemoradiation, and even mediastinoscopy may result in adhesions between the posterior wall of the artery and the anterior wall of the bronchus that may lead to injury to the artery. If there is evidence of such adhesions the azygos vein must be divided to obtain proximal control of the PA. The arterial anatomy to the right upper lobe varies significantly, sometimes present as a single large trunk or two or three smaller branches off the main PA (Fig. 71-3). Three single branches to respective segments of the upper lobe is the most unusual presentation, but when present, the branches can be doubly clipped and divided. A large main trunk may either be divided with a stapler or clipped and closed with running Prolene (3-0 or 4-0) or silk (3-0). After the vessels to the right upper lobe segments are identified and divided, a recurrent or posterior ascending branch, usually smaller than the main branches to the upper lobe, can be identified in most patients. Clipping is the best way to control it.

With the vasculature controlled, the bronchus is carefully dissected, first with scissors and then with a finger (Fig. 71-4). Nodes around the bronchus should be harvested both for staging and to permit better closure of the bronchus. The bronchus then can be divided after closure with a stapling device (heavy tissue or green loads should be used), or it can be divided with scissors or blade (being careful to leave enough tissue to close it without tension) and closed with interrupted absorbable sutures (PDS, usually 2-0 or 3-0). If stapled, the stapler's long axis should lie along the axis of the membranous trachea. By doing so, the flexible membranous trachea will seal the cartilaginous trachea.

The parenchyma then is divided and sealed. The anterior (minor) fissure between the upper and lower lobes is sometimes absent or is incomplete. In this case, a stapler can be used to divide the parenchyma between the upper and lower lobes. The middle lobe vein is used as a landmark to identify the fissure (Fig. 71-5). After the bronchus is divided, the upper lobe and bronchus should be lifted toward the apex of the chest and the parenchyma divided using multiple fires of a GIA stapler or clamps and then oversewn. The division is begun anteriorly just caudad to the middle lobe vein and then completed with sequential firings of the stapler, first completing the parenchymal division between the upper and middle lobes, identifying and avoiding the artery deep, and then completing the division posteriorly between the upper and lower lobes. The subcarinal and paratracheal nodes should be harvested, the lung inflated to test for air leaks, and the inferior pulmonary ligament taken down.

The paratracheal and subcarinal nodes are harvested and sent to the pathologist. The middle lobe is tacked to the lower lobe with 3-0 Vicryl sutures and the chest policed for bleeding points. Bronchial margins should be checked, at least, before closing the chest to ensure complete resection (Table 71-7).

Right Middle Lobectomy

Right middle lobectomies are rarely done alone and probably are done more commonly as bilobectomies, together with an upper lobectomy or a lower lobectomy (Table 71-8). The pulmonary arterial anatomy during a middle lobectomy is not straightforward. A single dominant vessel arises from the main trunk on the anterior surface directly across from the takeoff of the superior segmental artery and inferior to most of the middle lobe parenchyma (Fig. 71-6). It branches quickly into two short vessels that subsequently branch again. If the anterior aspect of the major fissure (between the lower and middle lobes) is complete or can be completed without significant air leaks, the middle lobe artery often can be divided first. If not, however, it must be divided last.

The middle lobe vein is identified as the smaller inferior branch of the superior vein. Rarely, a middle lobe vein can ascend from the inferior vein. This vein is small enough that it can be doubly clipped and divided or suture ligated (Fig. 71-7). The tissue deep to the vein then should be swept posteriorly to reveal the middle lobe bronchus. It should be stapled (many surgeons use a blue stapler load only for the middle lobe bronchus, using green or thick tissue loads for all the other bronchi) or divided and then closed with interrupted absorbable sutures (2-0 or 3-0 Vicryl or PDS). If the middle lobe artery has not been controlled, it is now either clipped or suture ligated.

The parenchyma between the upper and middle lobes then is divided with multiple firings of the stapler, and the specimen margins are sent to the pathologist. Subcarinal and paratracheal nodes are harvested and the lung inflated to test the bronchial and parenchymal closure. The chest should be policed for bleeding points and instrument counts confirmed.

Right Lower Lobectomy

When the major fissure is complete, a right lower lobectomy is the most straightforward of the lobectomies. The artery to the lower lobe, which branches into two trunks – the superior segmental and the basilar segment arteries (Fig. 71-8) – can be identified in the fissure. The takeoff of the middle lobe artery must be identified and preserved, and the lower artery then should be encircled and divided inferior to that takeoff but superior to the superior segmental artery (Fig. 71-9). Alternatively, the basilar segmental artery and superior segmental artery can be divided separately (Table 71-9).

The inferior vein is identified by taking down the inferior pulmonary ligament, harvesting the level 8 and 9 nodes at this time (Fig. 71-10). The phrenic nerve lies close along the anterior aspect of the ligament and must be protected and preserved. The inferior vein then is encircled and either divided with a vascular load stapler or clamped and oversewn with a running Prolene suture.

The parenchyma is divided anteriorly and posteriorly with a stapler (Fig. 71-11). This leaves only the bronchus, which must be divided in such a way as to protect the middle lobe bronchus.

When the fissure is not complete or scarring in the fissure prevents identification of the artery, a lower lobectomy can be done cephalad to caudad. In the right lower lobe, the vein, bronchus, and artery lie almost in a line (from caudad to cephalad) and can be divided in that order. With this approach, the inferior pulmonary ligament is taken down and the vein identified. It is divided and controlled either with a stapler or clamps and sutures, and the lower lobe then is elevated caudad. The pleural reflections anteriorly and posteriorly are divided, and the bronchus now comes into view. In patients with granulomatous disease or other inflammatory processes, the artery and bronchus will be adhesed. The bronchus must be carefully dissected away from the artery and then divided as described earlier. If the artery can be dissected away from the parenchyma and divided, that is ideal. Alternatively, the vein and bronchus can be retracted inferiorly, and blue (intermediate) stapler loads can be used to divide the parenchyma and artery together. From experience, it is safe to include the artery with parenchyma in an intermediate stapler load, as long as the bronchus has been divided and retracted away.

Pericardiectomy

Rarely, a tumor invading the pericardium around the inferior vein can be resected with an incision in the pericardium that avoids the phrenic nerve. This is usually easy because the phrenic nerve lies farther from the hilum at the level of the inferior vein than at the superior vein. After the pericardium is opened, approximately 1 to 1.5 cm of additional margin on the inferior vein is now available to resect the lower lobe without requiring a pneumonectomy (Fig. 71-12). This intrapericardial approach is more commonly used for pneumonectomy.

Left Upper Lobectomy

A left upper lobectomy truly is done in “tiger country.” The main PA appears in the left pleural space from the arch of the aorta. Both are close to the recurrent nerve and to the phrenic nerve (Fig. 71-13 and Table 71-10).

Order of Technique

While the right upper lobe almost always has to be taken from superior to inferior, the left upper lobe can be approached anteriorly, superiorly, posteriorly, or inferiorly. Approached anteriorly, the superior vein is mobilized away from the artery and then divided first. This uncovers the anterior aspect of the PA and allows sequential division of the pulmonary arterial vessels, the anterior and apicoposterior branches of the artery, and the lingular artery (Fig. 71-14). The parenchyma then is divided and finally the bronchus. This approach is best followed when the tumor adheres to the artery and dividing the vein can give better access to the main PA or branches of the PA.

If the mass lies in the lung periphery, a superior approach is usually best for two reasons—the arterial supply can be controlled first, and the fissure can be stapled and sealed easily. For this approach, the pleural reflection is first divided, and then the apicoposterior arterial branch (sometimes both the apicoposterior and anterior branches) is divided after the main PA is encircled with tape to control it (Fig. 71-15). The superior pulmonary vein then is divided. This usually leaves the bronchus and the lingular arteries. Ideally, the arteries and parenchyma should be harvested first and the bronchus last. However, the bronchus can be taken before the arteries if care is taken to avoid avulsing the arteries. As earlier, the bronchi can be closed with a heavy (green load) stapler or can be sewn with interrupted absorbable sutures (Vicryl 3-0 or PDS 3-0). The margins should be checked for evidence of disease, and the aortopulmonary nodes and subcarinal nodes should be harvested.

Problem Areas

Proximity to the aorta: Even tumors arising in the proximal upper lobe approaching the aorta seldom invade the aorta. However, bulk in the window at the origin of the PA can make access to the PA difficult. In this case, the adventitia and pleura that reflect off the aorta toward the PA can be divided and the mass mobilized inferiorly. This allows access to the proximal left PA, which then can be controlled just beyond its takeoff from the main PA. In addition, a large bulky tumor can potentially put torque on the main PA causing an adventitial “crack” which can lead to a full thickness injury and tear. If additional access is needed, two maneuvers can give additional mobility:

• Opening the pericardium

• Dividing the remnant of the patent ductus arteriosus

Either of these maneuvers put the recurrent nerve at risk.

The recurrent nerve: The vagus nerve descends from the neck in the coronal midline and crosses the aorta at the peak of the arch. The recurrent nerve branches off the vagus and curves superiorly toward the neck from the underside of the aorta. It is at risk with any mobilization of the PA and especially with aortopulmonary lymphadenectomy. The nerve should be visualized, and direct resection or injury should be avoided, but one must remember that the nerve is very sensitive to indirect injuries such as distant cautery or even mild traction.

Postoperative Clinical Note

After left upper lobectomy and nodal dissection, patients should be carefully evaluated for voice strength and potential aspiration within the first 12 hours after surgery. Any suspicious findings (hoarseness or coughing after drinking) should prompt video swallowing evaluation. Those patients with aspiration should not eat or drink until they receive successful swallowing therapy or vocal cord medialization.

Phrenic nerve injury: The phrenic nerve lies just anterior to the hilum and is at risk during dissection or from tumor invasion.

Left Lower Lobectomy: Complete or Nearly Complete Fissure

As with the right lower lobe, the left lower lobe can be approached superiorly if the fissure is complete or nearly so. In this case, the parenchymal division is completed first. The arteries to the superior segment and to the basilar segments in the fissure are divided next. Stapler division with vascular loads or ties with suture transfixation or double ties should be used to control the vessels.

After the arteries are controlled and divided, the vein can be divided in the same fashion as the artery. The vein may be identified posteriorly and dissected away from the bronchus (Fig. 71-16) or identified anteriorly by taking down the inferior ligament and encircling the vein. The vein then is divided in a standard fashion.

The parenchyma between the upper and lower lobes is divided in one of the manners described earlier, and the bronchus is closed either with a stapler or interrupted absorbable sutures (Fig. 71-17).

Left Lower Lobectomy: Absent or Incomplete Fissure

If the fissure is absent or very incomplete, left lower lobectomy can be done from the bottom up—that is, division of vein, bronchus, artery, and parenchyma, in that order. The pulmonary ligament is carefully taken down and the inferior vein is encircled and divided by the preferred method—stapler or suture division. Double ties are seldom used for this vein. The vein is deep to the bronchus which is deep to the artery, which is deep to the parenchyma. The divided vein is retracted inferiorly, and the bronchus, which is adjacent and immediately superior to the vein, is then dissected and divided and then closed either with a stapler or with absorbable sutures. The artery to the lower lobe is divided (being careful to preserve the lingular artery to the upper lobe), and the parenchyma is divided and sealed with stapler division. Alternatively, the artery and the parenchyma can be mass ligated and divided with staplers (blue loads) without problem. From experience, it is safe to include the artery with parenchyma in an intermediate stapler load, as long as the bronchus has been divided and retracted away.

As mentioned above in the description of right lower lobectomy, a tumor invading the pericardium around the inferior vein can be resected with an incision in the pericardium that avoids the phrenic nerve. This is usually easy, as the phrenic nerve lies further away from the hilum at the level of the inferior vein than at the superior vein. After the pericardium is opened, approximately one to one and a half additional centimeters of margin on the inferior vein now are available to resect the lower lobe without requiring a pneumonectomy. Unlike the case with pneumonectomy, the pericardium does not need to be reconstructed when a lobectomy is done.

Performing a careful lobectomy, assessing the margins, and completing a thorough lymphadenectomy are marks of a careful thoracic surgeon. Avoiding common postoperative complications are marks of a thorough clinician. Our patients deserve nothing less.

Dr. Roberts has provided an excellent, detailed description of each of the five lobectomies. Specifically, the hazards and pitfalls of each procedure are carefully described and reviewed. In my experience, the key steps in performing open or thoracoscopic lobectomy are opening the mediastinal pleura, removing the mediastinal and hilar lymph nodes as they are encountered, and then dissecting right onto the adventitia of the pulmonary arteries. Careful sharp dissection can ensure a safe anatomic lobectomy even after preoperative chemoradiation. Although we generally use the endoscopic linear vascular stapler for all the large PA branches, standard double ligation and/or suture ligation is used for smaller vessels to avoid avulsion injury to the PA. Finally, when performing a lobectomy, the left upper lobe PA dissection is the most difficult, in my opinion, as there usually are many short vessels. In contrast, the right upper lobectomy is the most straightforward as the PA usually is a separate trunk. In performing a middle lobectomy, the main pitfall is injury to the underlying main PA behind the branch PA. An option for difficult dissection includes the “bronchus first” approach. This technique, which I learned from surgeons who did many tuberculosis operations, is particularly helpful postchemoradiation in the right and left upper lobe situation. It involves a posterior approach to the upper lobe with sequential bronchial, arterial, and finally venous division.