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.
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 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).
Table 71-4Potential Hazards of Right Paratracheal Node Dissections ||Download (.pdf) Table 71-4Potential 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 to the packet and can be injured in those patients who have received preoperative chemoradiation
Any patients with granulomatous disease may have chronic inflammation and calcification which can make nodal dissection even more difficult than those patients who have received chemoradiation
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 In any case, a small benefit would be superseded by a surgical mishap.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).
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 71-5Potential Hazards of Right Upper Lobectomy ||Download (.pdf) Table 71-5Potential 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.
Solution—Open the pericardium and control the right main pulmonary artery during dissection.
Identifying and dividing the recurrent posterior artery.
Solution—avoid clipping this artery if you plan stapler division of the parenchyma. Instead, tie or use energy for this small vessel.
The phrenic nerve can be injured:
While taking down apical adhesions.
Solution—identify the phrenic nerve in its usual course on the lateral wall of the superior vena cava and track it superiorly.
While dividing the anterior parietal pleura.
Solution I—the nerve can be encased or trapped in nodes at the takeoff of the phrenic nerve. Carefully mobilize the nerve superior to and inferior to the area of entrapment prior to mobilization away from the base of the superior vein.
Solution II—leave the nerve in its place, and divide the separate branches of the superior pulmonary vein proximal to the area of entrapment.
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.
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 71-6Types of Staplers ||Download (.pdf) Table 71-6Types of Staplers
Vascular staplers, gray, white, or red, usually with a 2.5-mm staple length. They are used to close pulmonary artery or single pulmonary veins.
Medium thickness staplers, blue, usually with a 3.5-mm staple length. They are used to divide parenchyma or to control left atrium when tumor approaches close to the origin of the pulmonary vein.
Heavy thickness staplers, green, usually with a 4.8-mm staple length, or black with 5-mm staple length designed to close tissue up to 3 mm thick. 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 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.
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. 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.
Right upper lobectomy: The horizontal fissure is divided using a stapler. Note 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, before closing the chest to ensure complete resection (Table 71-7).
Table 71-7Checking the Margins ||Download (.pdf) Table 71-7Checking the Margins
Check all margins (bronchus, artery, vein, and parenchyma) that appear close
Bronchial margins are all that is necessary 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
To ensure that the appropriate tissue is evaluated
To prevent “surprise” positive margins, ask your pathologist to “freeze all margins to be subsequently evaluated”
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 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.
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.
Table 71-8Potential Hazards During Right Middle Lobectomy ||Download (.pdf) Table 71-8Potential 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.
Solution for both—dissect the main pulmonary artery and obtain control for any unusually difficult dissections. This allows quick control of the artery if there is injury.
Compromising the bronchus to the lower lobe while dividing the middle lobe bronchus:
Solution—clamp the middle lobe bronchus prior to division, and then inflate the lower lobe. If it does not inflate, consider intraoperative bronchoscopy to evaluate the lower lobe bronchus before dividing the bronchus.
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.
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. 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).
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 then divided.
Table 71-9Potential Hazards During Right Lower Lobectomy ||Download (.pdf) Table 71-9Potential 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.
Solution—clamp the lower lobe bronchus prior to division, and then inflate the right lung to confirm expansion of the middle lobe. If it does not inflate, consider intraoperative bronchoscopy to evaluate the lower lobe bronchus before dividing the bronchus.
Injuring the phrenic nerve while dissecting the hilum of the lower lobe.
Solution—be cognizant that the inferior course of the phrenic nerve may track posteriorly close to the inferior vein.
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.
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. 71-11). 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 vascular has been divided, the parenchyma is divided superior and inferiorly using 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 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.
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 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).
Left upper lobectomy: The proximity of the recurrent laryngeal and phrenic nerves and aorta can pose many obstacles to easy left upper lobectomy.
Table 71-10Potential Hazards During Left Upper Lobectomy ||Download (.pdf) Table 71-10Potential Hazards During Left Upper Lobectomy
Injury to the aorta:
Solution—don't do it!
Injury to the recurrent nerve:
While dissecting the pulmonary artery.
While performing lymphadenectomy.
Solution to both—identify the vagus nerve as it courses over the midpoint of the aorta. If suspicious nodes involve the vagus, the nerve can be divided close to the pulmonary artery, and the nodes teased away from the underside of the aorta, preserving the recurrent nerve.
Injury to the pulmonary artery:
While dividing the short arterial vessels.
While dividing the bronchus.
Solution to both—gain control of the left main pulmonary artery proximally by opening the pericardium, or by dividing the remnant of the patent ductus arteriosus to gain mobility.
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.
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 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.
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 apicoposterior and anterior arterial branches are divided.
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:
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.
Left lower lobectomy: The inferior pulmonary vein is divided in much 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. 71-17).
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.
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.