Viewed from the patient's side, the anatomy of the right hilum is a triangle with the pulmonary artery at the apex, the vein anterior, and the bronchus posterior (Fig. 62-1A). 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 pulmonary artery and to perform the paratracheal lymphadenectomy.
Right upper lobectomy. A. The anatomy of the hilum viewed from the patient's side forms a triangle. B. The azygos vein, which caps the triangle, can be divided to gain proximal control of the pulmonary artery.
Harvesting the mediastinal nodes is an important part of the procedure and can give more proximal exposure to the pulmonary artery 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 pulmonary artery and superiorly all the way to the subclavian artery at the thoracic inlet (Fig. 62-1B). 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 62-4).
Table 62-4. Potential Hazards of Right Paratracheal Node Dissections |Favorite Table|Download (.pdf)
Table 62-4. Potential Hazards of Right Paratracheal Node Dissections
- The superior aspect of the right pulmonary artery is present at the inferior aspect of the nodal packet.
- The right recurrent nerve is present at the apex of the nodal packet.
- Small venous branches off the superior vena cava (or the cava itself) can be injured during dissection.
- The pericardium and aorta lie deep into the packet and can be injured in patients who have received preoperative chemoradiation.
While many ascribe importance to the order of division of the hilar structures, there are no studies to confirm either a technologic or 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 In any case, a small benefit would be superseded by a surgical mishap.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 pulmonary artery first, then the vein, and then the bronchus, unless the artery is covered by the vein, in which case the vein, then artery, and then bronchus are divided in that order.
After dividing the upper lobe branch of the superior vein and the main upper lobe pulmonary artery (which may be present as two or three branches), a single small, more inferior branch of the ongoing pulmonary artery usually ascends superiorly to the upper lobe (Fig. 62-2). 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 62-5).
Right upper lobectomy. Pulmonary arterial anatomy pertinent to right upper lobectomy. A single, more inferior branch of the pulmonary artery usually ascends superiorly to the right upper lobe and must be controlled and divided.
Table 62-5. Potential Hazards of Right Upper Lobectomy |Favorite Table|Download (.pdf)
Table 62-5. Potential Hazards of Right Upper Lobectomy
The pulmonary artery can be injured:
- While developing the plane between the right upper lobe bronchus and the pulmonary artery.
- While identifying and dividing the recurrent posterior artery.
The phrenic nerve can be injured:
- While taking down apical adhesions.
- While dividing the anterior parietal pleura.
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 pulmonary artery anteriorly, the vein is approached and the middle lobe vein identified and preserved (Fig. 62-3). 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 62-6).
Right upper lobectomy, hilar exposure. If the superior vein lies anterior to the pulmonary artery, the middle lobe vein must be identified and preserved.
Table 62-6. Types of Staplers |Favorite Table|Download (.pdf)
Table 62-6. Types of Staplers
- Vascular staplers, either gray, white, or red, usually with a 2.5-mm gap. They are used to close the pulmonary artery or single pulmonary veins.
- Medium-thickness staplers, blue, usually with a 3.5-mm gap. They are used to divide parenchyma or to control left atrium.
- Heavy-thickness staplers, green, usually with a 4.8-mm gap. They are used for thick pulmonary parenchyma or for bronchi.
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 pulmonary artery. 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 pulmonary artery (see Fig. 62-2). 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. 62-4). 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.
Right upper lobectomy. After the vasculature is controlled, the bronchus is dissected.
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. 62-5). 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.
Right upper lobectomy. The horizontal fissure is divided with a stapler. Note that the middle lobe vein serves as a guide for locating the minor fissure between the upper and lower lobes.
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, prior to closing the chest to ensure complete resection (Table 62-7).
Table 62-7. Checking the Margins |Favorite Table|Download (.pdf)
Table 62-7. Checking the Margins
Check all margins (bronchus, artery, vein, and parenchyma) that appear close.
Bronchial margins are sufficient for most lobectomies.
Cut your own margins.
- To prevent nodal metastases from being read as positive margins:
Clean off all nodal tissue from bronchus, artery, or vein
Wash margin tissue in distilled water to lyse free-floating cells.
Consider additional resection for any positive margin.
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 62-8). 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. 62-6). 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.
Table 62-8. Potential Hazards during Right Middle Lobectomy |Favorite Table|Download (.pdf)
Table 62-8. Potential Hazards during Right Middle Lobectomy
Injuring the ongoing pulmonary artery
- Manipulating the lung after division of the bronchus and vein
- While dissecting out the middle lobe artery in the main fissure
Compromising the bronchus to the lower lobe while dividing the middle lobe bronchus
Right middle lobectomy. Pulmonary arterial anatomy pertinent to right middle lobectomy. Note the middle lobe artery, a single dominant vessel arising from the main trunk on the anterior surface across from the superior segmental artery.
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. 62-7). 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.
Right middle lobectomy. Middle lobe vein is double-clipped and divided 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.
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. 62-8)—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. 62-9). Alternatively, the basilar segmental artery and superior segmental artery can be divided separately (Table 62-9).
Right lower lobectomy. Pulmonary arterial anatomy pertinent to right lower lobectomy. The artery to the lower lobe branches into two segments, the superior segment and basilar segment.
Right lower lobectomy. After identifying the middle lobe artery, which is preserved, the basilar segmental artery is encircled and divided.
Table 62-9. Potential Hazards during Right Lower Lobectomy |Favorite Table|Download (.pdf)
Table 62-9. Potential Hazards during Right Lower Lobectomy
- Injuring the right middle lobe artery during dissection of the lower lobe arteries.
- Compromising the lumen of the right middle lobe bronchus while dividing the right lower lobe bronchus.
- Injuring the phrenic nerve while dissecting the hilum of the lower lobe.
The inferior vein is identified by taking down the inferior pulmonary ligament, harvesting the level 8 and 9 nodes at this time (Fig. 62-10). 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.
Right lower lobectomy. The inferior pulmonary ligament is taken down, with caution to avoid injury to the phrenic nerve, to expose the inferior pulmonary vein. This vein is encircled and divided or clamped and oversewn.
The parenchyma is divided anteriorly and posteriorly with a stapler (Fig. 62-11). This leaves only the bronchus, which must be divided in such a way as to protect the middle lobe bronchus.
Right lower lobectomy. After the vasculature has been divided, the parenchyma is divided superiorly and inferiorly with a stapler, leaving only the bronchus, which is carefully dissected away from the artery and then divided.
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.
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 1–1.5 cm of additional margin on the inferior vein is now available to resect the lower lobe without requiring a pneumonectomy (Fig. 62-12).
Pericardiectomy. A 1- to 1.5-cm margin of inferior pulmonary vein is available for resecting the lower lobe without necessitating pneumonectomy.
A left upper lobectomy truly is done in “tiger country.” The main pulmonary artery 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. 62-13 and Table 62-10).
Left upper lobectomy. Owing to the proximity of the recurrent laryngeal and phrenic nerves, left upper lobectomy poses many obstacles to easy resection.
Table 62-10. Potential Hazards during Left Upper Lobectomy |Favorite Table|Download (.pdf)
Table 62-10. Potential Hazards during Left Upper Lobectomy
Injury to the aorta
Injury to the recurrent nerve
- While dissecting the pulmonary artery
- While performing lymphadenectomy
Injury to the pulmonary artery
- While dividing the short arterial vessels
- While dividing the bronchus
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 pulmonary artery and allows sequential division of the pulmonary arterial vessels, the anterior and apicoposterior branches of the artery, and the lingular artery (Fig. 62-14). 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 pulmonary artery or branches of the pulmonary artery.
Left upper lobectomy. Pulmonary arterial anatomy pertinent to left upper lobectomy, which can be approached anteriorly, superiorly, posteriorly, or inferiorly.
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 apico posterior arterial branch (sometimes both the apico posterior and anterior branches) is divided after the main pulmonary artery is encircled with tape to control it (Fig. 62-15). 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.
Left upper lobectomy. A superior approach to access a peripheral lung mass in the left upper lobe. The main pulmonary artery is encircled with tape to establish control, and the apico-posterior and anterior arterial branches are divided.
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 pulmonary artery can make access to the pulmonary artery difficult. In this case, the adventitia and pleura that reflect off the aorta toward the pulmonary artery can be divided and the mass mobilized inferiorly. This allows access to the proximal left pulmonary artery, which then can be controlled just beyond its takeoff from the main pulmonary artery.
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 pulmonary artery 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.
The phrenic nerve lies just anterior to the hilum and is at risk during dissection or from tumor invasion.
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. 62-16) or identified anteriorly by taking down the inferior ligament and encircling the vein. The vein then is divided in a standard fashion.
Left lower lobectomy. The inferior pulmonary vein is divided in much the same fashion as the pulmonary artery. The vein is identified and dissected away from the bronchus.
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. 62-17).
Left lower lobectomy. The lower lobe superior segment bronchus is closed with a stapler or interrupted absorbable sutures after the parenchyma between the upper and lower lobes has been divided.