Acs0414 Pulmonary Resection


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Acs0414 Pulmonary Resection

  1. 1. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 1 14 PULMONARY RESECTION Ara Vaporciyan, M.D., F.A.C.S. Anatomic resections of the lung (including pneumonectomy and placed in the supine position, with a pillow placed in such a way as lobectomy) are the standard operative techniques employed to to elevate the area of the thorax that will be operated on. treat both neoplastic and nonneoplastic diseases of the lung. Any When the patient is in the lateral decubitus position, several surgeon who intends to operate on the pulmonary system must be measures should be adopted to guard against injury. Adequate keenly aware of the anatomy of the pulmonary vasculature, the padding should be employed to prevent the development of pres- bronchi, and the relation between the two. There is no substitute sure points on the contralateral lower extremity. A low axillary roll for this degree of familiarity. Detailed discussions are available in should be used to prevent injury to the contralateral brachial plexus existing anatomy textbooks. In what follows, I describe several of and shoulder girdle. Finally, adequate padding should be placed the more common techniques employed for anatomic resections of beneath the head to keep the cervical spine in a neutral position. the lung. GENERAL TECHNICAL CONSIDERATIONS Preoperative Evaluation Incisions Detailed discussion of the physiologic evaluation of the patient Posterior lateral thoracotomy remains the standard incision for and of the indications for lobectomy or pneumonectomy is beyond anatomic pulmonary resections; however, safe and complete resec- the scope of this chapter. In general, the patient must have suffi- tions can also be performed through a variety of smaller incisions, cient pulmonary reserve to tolerate the planned resection. In addi- including posterior muscle-sparing, anterior muscle-sparing, and tion, it is essential to carry out a thorough evaluation of all other axillary thoracotomies. In most cases, the thorax is entered at the systems, especially the cardiac system. In patients who have fifth intercostal space, an approach that affords excellent exposure received preoperative chemotherapy, the hematologic and renal of the hilar structures.The anterior muscle-sparing thoracotomy is systems should receive particular attention. generally placed at the fourth intercostal space because of the more caudal positioning of the anterior aspects of the ribs. Although a sternotomy may be employed to gain access to the upper lobes, it Operative Planning does not provide good exposure of the lower lobes and the bronchi. ANESTHESIA Thoracoscopic lobectomy [see 4:10 Video-Assisted Thoracic Surg- Although pulmonary resections can be performed with bilater- ery] is being performed with increasing frequency, especially for al lung ventilation, careful hilar dissection is greatly facilitated by early-stage lesions. This procedure employs two or three 1 cm using unilateral lung ventilation. The advent of double-lumen ports and a utility thoracotomy (frequently in the axillary position) endotracheal tubes and bronchial blockers has made it possible to for instrumentation and removal of the specimen. Rib spreading is isolate the ipsilateral lung and has made it easier for surgeons to not necessary, because visualization is achieved via the thoraco- carry out complex hilar dissections with the required precision. In scope. The various thoracoscopic lobar resections are generally patients with centrally located tumors, care must be taken with similar with regard to isolation and division of the hilar vessels and tube placement: inadvertent trauma to an endobronchial tumor bronchi. Complete nodal dissections are also performed thoraco- during placement of a double-lumen tube can lead to significant scopically. The main advantages of this approach seem to be bleeding and compromise of the airway. Bronchoscopic confirma- reduced postoperative pain and earlier return to normal activity, tion of tube position is recommended after the patient has been but to date, no randomized trials have shown these advantages to positioned. be significant. Because of the technical challenges posed by thora- Requirements for monitoring and intravenous access are deter- coscopic pulmonary resections, surgeons should have a complete mined by the patient’s preoperative status and by the complexity mastery of the hilar anatomy before attempting these procedures. of the resection. In most cases, the standard practice is to place a radial arterial catheter, two large-bore peripheral intravenous cath- Special Intraoperative Issues eters, and a Foley catheter, with more invasive monitoring em- Upon entry into the thoracic cavity, all benign-appearing filmy ployed if mandated by the patient’s clinical condition. Thoracic adhesions should be mobilized. Any malignant-appearing, broad- epidural catheters are also commonly employed for postoperative based, or dense adhesions should be noted, and a decision whether pain control. If carefully placed by an experienced anesthesiologist, to perform an extrapleural dissection or a chest wall resection these catheters can remain in place for as long as 7 days or until should be made on the basis of the depth of involvement and the the chest tubes are removed. preoperative imaging studies. If there is reason to believe that the chest wall or the parietal pleura may be involved, a more aggressive PATIENT POSITIONING approach may be required to achieve a complete resection. These Patients are routinely placed in the lateral decubitus position, techniques are beyond the scope of this chapter. with the table flexed just cephalad to the superior iliac crest. This Once the lung is freed of all adhesions, the inferior pulmonary positioning allows sufficient access for most incisions. If an anteri- ligament is divided and the lung rendered completely atelectatic. or thoracotomy or a sternotomy is planned, the patient may be The entire lung and the parietal pleura are inspected and palpat-
  2. 2. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 2 ed. In patients with malignant disease, biopsies of any suspicious often apply staples only to the proximal side of the bronchus and nodules are performed. The presence or absence of pleural fluid divide the bronchus distal to the staple line. Once the stapler is should be noted; if fluid is present, it should be aspirated and sent applied, every effort should be made to minimize its movement for immediate cytologic analysis. during firing, so as to prevent injury to the remaining proximal Frequently, the fissures are incomplete as a consequence of bronchial segment. With the stapler applied but not yet fired, the congenital absence, inflammatory disease, or a neoplasm. If the remaining lung should be ventilated to determine whether there adhesions within the fissure are filmy, they may be divided sharply is any impairment of ventilation secondary to placement of the or with the electrocautery while the lung is being ventilated. If the stapler too close to a proximal lobar bronchus. Only when the adhesions are more densely adherent, the fissures may have to be absence of ventilatory impairment has been confirmed should the completed with staplers. During resection for malignancy, any evi- stapler be fired. When bronchial length is limited, one may per- dence of tumor extension across a fissure or of hilar nodal involve- form suture closure of the bronchial stump rather than attempt to ment should be noted. A decision is then made regarding the force a stapler around the bonchus. Whenever there is a high risk extent of the required resection. If there is only minor extension, of bronchial stump dehiscence (e.g., after chemotherapy, radio- wedge resection of a portion of the additional lobe is indicated. If, therapy, or chemoradiotherapy; in patients for whom adjuvant however, the involvement is significant, segmentectomy, bilobec- therapy is planned; or after right pneumonectomy), a vascularized tomy, or pneumonectomy may be indicated. Often, I develop the rotational tissue flap (e.g., from the pericardium, the pericardial fat fissures during ventilation until a dense or incomplete region is pad, or intercostal muscle) should be used to reinforce the bron- encountered, at which point I complete the remainder of the fis- chial closure. sure with staples. For this approach to work, the vascular and bronchial anatomy must already have been completely delineated. Closure and Drainage If the vascular structures cannot be identified in the fissure Once the bronchial closure is complete, the next step is to test because the fissure is fused, the pulmonary artery branches will its adequacy. The bronchial stump is submerged under normal have to be approached from the anterior and posterior hilum. saline, and the lung is inflated to a tracheal pressure of 45 cm H2O. Traditionally, during a lobectomy, the arterial branches are Any area of hilar dissection and divided fissures should be evalu- divided first, followed by the venous branches. However, if condi- ated in a similar fashion. Significant parenchymal air leaks should tions exist that limit exposure (e.g., a centrally placed tumor or be repaired with interrupted fine sutures (e.g., 4-0 polypropylene). significant inflammation and scarring), the surgeon should start If the air leak is from a diffuse raw surface, especially after upper with the structures that provide the most accessible targets. Veins lobectomy, construction of a pleural tent should be considered. may be ligated first. Proponents of this approach believe that it Any air leak from the bronchial stump should be assessed very may limit the escape of circulating tumor cells (an event that carefully. A simple repair with fine absorbable sutures may suffice, rarely, if ever, occurs); opponents claim that initial vein ligation or the entire closure may have to be redone. Strong consideration may lead to venous congestion and retention of blood that is sub- should be given to reinforcing the stump with vascularized tissue sequently lost with the specimen, though peribronchial venous (see above). channels will frequently prevent this result. The bronchus may The chest is usually drained with two chest tubes that are posi- also be ligated first. However, there are two points that should be tioned anteriorly and posteriorly and exit through separate stab kept in mind if this is done. First, the distal limb of the bronchus incisions in the chest wall. If an epidural or a paravertebral catheter (the specimen side) should be oversewn to prevent drainage of is being employed for postoperative pain management, the chest mucus into the chest. Second, after division of the bronchus, the tubes should exit through an intercostal space that is no more than lobe is much more mobile; therefore, to prevent avulsion of the two spaces below the intercostal space used for entry into the pulmonary artery branches, care should be taken not to employ chest. Failure to follow this recommendation is likely to result in excessive torsion or traction. pain originating from the chest tube site that will not be ade- The techniques used for dissection, ligation, and division of pul- quately addressed postoperatively and will lead to a significant monary arteries and their branches differ from those used for increase in discomfort. other vessels. Pulmonary vessels are low-pressure, high-flow, thin- After a pneumonectomy, the chest tubes can be omitted. If this walled, fragile structures. Accordingly, for rapid and safe dissec- option is chosen, a needle should be used to aspirate 1,000 to tion, a perivascular plane, known as the plane of Leriche, should 1,200 ml of air from the hemithorax operated on after closure of be sought.This plane may be absent in the presence of long-stand- the skin. If a chest tube is used, a balanced drainage system is ing granulomatous or tuberculous disease, after major chemother- employed without suction. At most institutions, suction is apy, after thoracic radiotherapy, and in cases of reoperation. In employed postoperatively for all other resections (i.e., lobectomy, these situations, proximal control of the main pulmonary artery segmentectomy, and wedge resection); however, careful use of and the two pulmonary veins may be necessary before the more water seal in selected patients (i.e., those with small air leaks whose peripheral arterial dissection can be started. Before any pulmo- lungs do not collapse while on water seal) may allow earlier with- nary vessel is divided, it should be controlled either with two sep- drawal of the tube. arate suture ligatures proximal to the line of division or with vascu- lar staples; stapling devices are especially useful for larger vessels. Exposure of the bronchus should not involve stripping the Operative Technique bronchial surface of its adventitia. Aggressive dissection may com- RIGHT LUNG promise the vascular supply and lead to impaired healing and bronchial dehiscence. Overlying nodal tissues should be cleared, and major bronchial arteries should be clipped just proximal to the Right Upper Lobectomy point of division. Bronchial closure has been greatly facilitated by Dissection begins within the interlobar fissure, and the pul- the use of automatic staplers. Because the bronchus is frequently monary artery is exposed at the junction of the major and minor the last structure to be divided before removal of the specimen, I fissures [see Figure 1]. In many cases, the artery is partially
  3. 3. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 3 obscured by a level 11 interlobar lymph node, which should be fired, the right lung is ventilated to confirm that the bronchus removed. Also present is the posterior segmental branch of the intermedius has not been compromised. The stapler is fired, the superior pulmonary vein, which traverses the fissure in a posterior- bronchus is divided, and the specimen is removed. to-anterior direction.The pulmonary artery lies medial and inferi- To prevent middle-lobe syndrome resulting from torsion of the or to this venous branch. narrow hilum of the middle lobe after an upper lobectomy, the Once the pulmonary artery is identified, the branches within middle lobe should be secured to the lower lobe. Once the lungs the fissure are exposed, including the posterior ascending artery are reexpanded, a small portion of the lower lobe and a compara- to the right upper lobe, the right middle-lobe artery, the superior ble portion of the middle lobe are grasped along the major fissure. segmental artery to the right lower lobe, and the basilar branch- A single application (or, at most, two applications) of a TA stapler es to the right lower lobe. If the exposure is adequate, the poste- should suffice to secure the lobes to each other at this site and thus rior ascending branch can be ligated and divided. If additional prevent middle-lobe torsion. length is required, the fissure between the superior segment of the lower lobe and the posterior segment of the upper lobe can Right Middle Lobectomy be completed. This is accomplished by opening the pleura in the The initial steps in a right middle lobectomy are similar to those posterior hilum along the lateral edge of the bronchus inter- in a right upper lobectomy. The pulmonary artery and its branch- medius. A level 11 lymph node will be encountered between the es are identified within the fissure.The middle-lobe artery is iden- right upper-lobe bronchus and the bronchus intermedius. tified [see Figure 1]. Not infrequently, there are two middle-lobe Removal of this interlobar node (sometimes referred to as the arteries. When this is the case, the most proximal branch is com- sump node) will expose the posterior ascending branch. Either monly located across from the posterior ascending branch to the the branch can be directly ligated and divided via this exposure, right upper lobe. Once the anatomy has been confirmed, the arte- or the fissure can be completed with gastrointestinal anastomo- rial branches to the middle lobe can be individually ligated and sis (GIA) staplers, with the vessel ligated and divided after com- divided. If additional exposure is needed before ligation, the fis- pletion of the fissure. The lung is then rotated posteriorly, and the pleura is incised posterior to the course of the phrenic nerve, which usually passes Right close to the base of the superior pulmonary vein. The phrenic Middle Lobe nerve is carefully and gently mobilized anteriorly.The superior pul- Interlobar monary vein is dissected, and the apical, anterior, and posterior Pulmonary Artery Right Middle- branches are encircled [see Figure 2]. Care is taken to preserve the Lobe Artery Posterior middle-lobe branches. The branches draining the upper lobe are Segmental Basilar Segmental then ligated and divided or controlled with a vascular stapler. Branch of Arteries to Right Division of the veins before division of the arterial supply will not Right Superior Lower Lobe cause the lobe to become engorged. Instead, through collateral Pulmonary Vein Right venous drainage to the middle lobe or via bronchial venous chan- Lower nels, blood will be shunted away from the upper lobe. Lobe The interlobar (or truncus posterior) branch of the right pul- monary artery will be visible as it courses posterior to the superior pulmonary vein branches. Dissection continues along the lateral surface of the interlobar artery. Once the branches to the middle- lobe artery are identified, the dissection should reach the region previously dissected within the fissure. The fissure between the middle lobe and the upper lobe can now be completed through serial application of GIA staplers. The right upper lobe is then rotated more inferiorly to provide a better view of the superior aspect of the hilum. This step allows complete exposure of the truncus anterior branch. Frequently, the truncus anterior branch originates from the main right pulmonary artery medial to the course of the superior vena cava; some ele- Right ments of the pericardium may also encircle the artery at this loca- Upper Lobe tion. Once the vessel is exposed, it is either suture-ligated and divided or transected with an endovascular stapler. Superior The upper lobe is retracted superiorly and posteriorly, and the Posterior Ascending Segmental Branch to Right Branch to Right interlobar artery is gently retracted anteriorly.The bronchus to the Upper Lobe Lower Lobe right upper lobe is circumferentially exposed, and all nodal tissue surrounding the right upper-lobe bronchus is swept distally so that Figure 1 Right upper lobectomy. Shown is the surgeon’s view of it can be included with the specimen. Every effort is made to avoid the right interlobar fissure. The fissures have been completed, and the segmental arteries to the upper, middle, and lower lobes have devascularizing the bronchus. Once an adequate length of the been identified. The posterior ascending branch to the upper lobe right upper-lobe bronchus is exposed, the lung is rotated anterior- most commonly varies with respect to size and origin. This vessel ly to allow visualization of the course of the bronchus intermedius may be absent or diminutive and may arise from the superior [see Figure 3].The bronchus is ligated with a transverse anastomo- segmental branch to the lower lobe. The posterior segmental vein sis (TA)–30 stapler loaded with 4.8 mm staples. Care is taken to draining into the superior pulmonary vein (not seen) is clearly achieve close apposition of the anterior wall to the posterior mem- visualized in the right upper lobe, lateral to the pulmonary artery branous wall of the bronchus. With the stapler applied but not branches.
  4. 4. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 4 Phrenic Right Mainstem Pericardium Nerve Bronchus Right Superior Pulmonary Artery Vena Cava Trachea Right Superior Pulmonary Vein Azygos Vein Middle-Lobe Vein Vagus Nerve Pulmonary Ligament Posterior Segmental Right Vein to Right Upper Lobe Upper Lobe Truncus Anterior Branch Interlobar Artery Figure 2 Right upper lobectomy. Shown is the surgeon’s view of the anterior right hilum. The apical venous branches of the superior pulmonary vein obscure the interlobar pulmonary artery and, to a lesser degree, the truncus anterior branch. Division of these venous branches during upper lobectomy improves exposure of the truncus anterior. The splitting of the main pulmonary artery into its two main branches may occur more proximally, and care should be taken to identify both branches before either one is divided. Another significant possible variation is a branch of the middle-lobe vein that arises from the intrapericardial portion of the superior pulmonary vein. sures can be completed to yield added exposure of a proximal mid- dle-lobe artery. Once the arteries are divided (or if additional exposure is required), the lung is rotated posteriorly to expose the superior pulmonary vein [see Figure 2].The branches to the middle lobe are carefully identified, doubly ligated, and divided.The posterior seg- mental branch of the superior pulmonary vein should now be eas- ily identifiable, originating just cephalad to the middle-lobe vein and coursing posteriorly (lateral to the interlobar artery) to drain the posterior segment of the right upper lobe. As noted (see above), this venous branch is easily identified during dissection of the interlobar artery within the fissure. To complete the fissure between the upper and middle lobes, dissection continues along the caudal and lateral surface of the posterior segmental venous branch until the previously performed dissection of the interlobar artery within the fissure is reached. The fissure is then completed through serial application of GIA staplers. When the fissure is complete, the surgeon has a clear view of the posterior segmental Figure 3 Right upper lobectomy. Shown is the surgeon’s view of branch of the superior pulmonary vein and the interlobar branch the posterior right hilum. The carina, the right mainstem of the pulmonary artery coursing posterior and medial to the bronchus, the right upper lobe, and the bronchus intermedius are veins. If the proximal arterial branch to the middle lobe could not easily seen. The interlobar sump node has been removed and the be safely ligated from the fissure before, it should be easily acces- fissure completed, and the posterior ascending branch of the pul- monary artery is visible. Care should be taken not to injure this sible now. vessel during division of the fissure. It can be ligated via this The middle lobe is then rotated superiorly and posteriorly to approach if it cannot be adequately exposed from the fissure. expose the right middle-lobe bronchus [see Figure 4], which usual- Both the truncus anterior and the posterior ascending branch of ly arises anterior and inferior to the right middle-lobe branches of the pulmonary artery lie directly anterior to the right upper-lobe the pulmonary artery. The basilar artery branches to the right bronchus, and care should be taken not to injure these vessels lower lobe are gently mobilized posteriorly to expose the bronchus during bronchial encirclement. The bronchial arteries course intermedius and the origin of the right middle-lobe bronchus. along the medial and lateral edges of the bronchus intermedius.
  5. 5. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 5 Peribronchial lymph nodes located in this region should be dis- sected and removed, with care taken not to injure the bronchial arterial branches. Once the bronchus is free, it is either divided and ligated with an automatic stapler or transected and oversewn as previously described (see above). Right Lower Lobectomy Once again, the pulmonary artery is exposed within the oblique fissure. The pulmonary branches to the superior segment and the basilar segments of the right lower lobe are identified [see Figure 1]. All branches within the fissure are identified, including the middle- lobe artery and the posterior ascending branch to the right upper lobe. The superior segmental artery is encircled and doubly ligat- ed, with care taken not to injure the posterior ascending branch if it arises from or close to the origin of the superior segmental branch. The basilar segmental branches are then encircled and doubly ligated, with the same care taken not to injure the middle- Right Mainstem Inferior lobe branch. Both vessels are then divided. Bronchus Pulmonary Vein The fissure between the superior segment of the lower lobe and the posterior segment of the upper lobe is frequently incomplete. Figure 5 Right lower lobectomy. Shown is the surgeon’s view of If necessary, it is completed as previously described [see Right the right inferior pulmonary vein. For encirclement of this vein, dissection may also have to be performed on its anterior surface. Upper Lobectomy, above]. The pleura is incised along the bron- The branch to the superior segment can be seen overlying the ori- chus intermedius, and the lymph node (sump node) just distal to gin of the superior segmental bronchus. the takeoff of the right upper-lobe bronchus is removed, so that the previously dissected pulmonary artery is exposed. Serial applica- tion of GIA staplers is employed to complete the fissure. plete). The pleura is incised within the anterior hilum to allow The fissure between the middle and lower lobes may also have identification of the superior and inferior pulmonary veins. The to be completed (though in many cases, it is congenitally com- basilar segmental bronchi and the middle-lobe bronchus should be exposed. Removal of lymphoid tissue allows easy application of a GIA stapler to complete the fissure. Ligated Stump The inferior pulmonary vein is then encircled as it exits the peri- of Right Middle- Middle- cardium [see Figure 5]. This step is facilitated by dissecting the Lobe Artery Lobe superior edge of the inferior pulmonary vein with the lung rotated Right Bronchus first anteriorly and then posteriorly. Once encircled, the pulmonary Middle Lobe vein can easily be ligated and divided with a vascular stapler. Right Division of the lower-lobe bronchus is best accomplished Upper Lobe through the fissure; this approach facilitates identification of the middle-lobe bronchus and helps prevent inadvertent damage to or compromise of the origin of this structure. Level 11 and 12 lymph nodes are cleared distally along the bronchi to expose the origin of the superior segmental bronchus [see Figure 6]. In some patients, there is adequate length to permit oblique placement of a stapler for control of all the lower-lobe segmental bronchi without com- promise of the middle-lobe bronchus. If this step is not possible, separate ligation and division of the superior segmental bronchus and of all the basilar bronchi as a unit should be performed. The lung is rotated anteriorly, and the bronchus intermedius is dissected distally until the origin of the superior segmental bron- chus is identified from this side. The branch of the inferior pul- monary vein draining the superior segment will be encountered and should be mobilized distally to allow adequate exposure of the supe- rior segmental bronchus origin. This bronchus can now be encir- cled, ligated, and divided with a stapler or divided and oversewn. Next, the basilar segmental bronchi are encircled at a point where closure will not affect airflow to the middle-lobe bronchus. Appropriate placement is confirmed by asking the anesthesiologist to ventilate the right lung while the stapler or clamp is applied to Right Lower the base of the basilar bronchi. If placement is adequate, the basi- Lobe lar segmental bronchi are ligated and divided. Figure 4 Right middle lobectomy. Shown is the surgeon’s view Right Pneumonectomy of the right middle-lobe bronchus. Gentle retraction of the basi- lar segmental artery to the lower lobe posteriorly allows clear With the pleura incised circumferentially around the hilum, the visualization of the origin of the middle-lobe bronchus. lung is rotated inferiorly and posteriorly [see Figure 2]. The main
  6. 6. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 6 Posterior Segmental Branch of Right Middle- Superior Pulmonary Vein Lobe Artery Right Middle Lobe Posterior Ascending Artery to Right Upper Lobe Divided Inferior Lower-Lobe Pulmonary Vein Bronchus Esophagus Figure 6 Right lower lobectomy. Shown is the surgeon’s view of the right fissure after division of the lower-lobe vessels. The decision whether to divide the bronchi separately or to transect them with a single oblique application of the stapler depends on the prox- imity of the middle-lobe bronchus to the superior segmental and basilar bronchi. Anterior Left Pulmonary Left Recurrent Segmental Artery Laryngeal Nerve Apicoposterior Artery Left Vagus Segmental Artery Nerve Lingular Segmental Artery Aorta Left Upper Lobe Left Lower Lobe Superior Basilar Segmental Artery Segmental Arteries Figure 7 Left upper lobectomy. Shown is the surgeon’s view of the left interlobar fissure. The recurrent laryngeal nerve can be seen coursing lateral to the ligamentum arteriosum. The arterial branches supplying the left upper lobe between the apico- posterior segmental branch and the lingular branch can vary substantially in number and size. Another frequently encountered variation is a distal lingular branch that arises from a basilar segmental branch.
  7. 7. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 7 Phrenic Nerve suture closure is selected instead, the bronchus is divided with the Superior clamp placed on the distal bronchus to prevent spillage.The open Pulmonary Left Pulmonary end of the bronchus is then closed with nonabsorbable simple Vein Artery sutures, with the cartilaginous wall approximated to the membra- nous wall. To guard against necrosis of the bronchus, care should Aorta be taken not to tie the sutures too tightly. Coverage of the pneu- Apical Left Upper monectomy stump with viable tissue is preferred, especially if the Branch Lobe patient has received or will receive chemotherapy, radiation thera- py, or both. The ideal choice for this purpose is either a rotated intercostal muscle flap or a pericardial fat pad rotational flap. The flap is secured with carefully placed 4-0 polypropylene sutures. In the preceding description, the artery is divided first, followed by the individual veins and finally by the bronchus; however, the steps of this operation can be carried out in any order. The posi- tion of the tumor may make the approach I describe difficult. For example, an anteriorly placed tumor may hinder exposure of the anterior hilum. In this situation, the bronchus can be divided first, and the pulmonary artery can be approached from the posterior hilum. As another example, if the tumor is very proximal, the peri- cardium can be entered via a U-shaped incision along the anteri- or, caudal, and posterior hilum.The pulmonary veins can then be divided en masse as they originate from the left atrium, and the pulmonary artery can be divided as it courses posterior to the ascending aorta. LEFT LUNG Left Lower Left Upper Lobectomy Lobe After the thorax is entered, the lung is rendered atelectatic and the thorax is explored.The inferior pulmonary ligament is divided. The interlobar fissure is developed with a combination of sharp Figure 8 Left upper lobectomy. Shown is the surgeon’s view of and electrocautery dissection. The posterior aspect of the fissure, the anterior left hilum. The apical branches of the superior pul- between the apicoposterior segment of the left upper lobe and the monary vein course anterior to the apicoposterior branches of the superior segment of the left lower lobe, is completed (with a linear pulmonary artery. If additional vessel length is needed because of stapler if necessary) to expose the proximal portion of the pul- the presence of a central tumor, the pericardium may be entered monary artery. and the vein divided at that location. With the lung retracted inferiorly, dissection continues proximal- ly along the pulmonary artery.The pleura is incised under the arch trunk of the right pulmonary artery is exposed as it exits the peri- of the aorta to expose the left main pulmonary artery. A variable cardium posterior to the vena cava. Care is taken not to dissect dis- number of small vessels and vagal branches to the lung are encoun- tally on the vessel and not to encircle only the truncus anterior tered that must be ligated and divided. Care is taken not to injure branch by mistake. Ligation and division of the right pulmonary the recurrent laryngeal nerve as it branches from the vagus and trav- artery can be accomplished in several different ways; either divid- els under the arch just distal to the ligamentum arteriosum. ing the vessel between clamps and oversewing it with 3-0 nonab- The left upper lobe is then retracted anteriorly and superiorly to sorbable suture material or using vascular staplers is acceptable. expose the pulmonary arteries supplying the lobe [see Figure 7]. Next, attention is directed toward the superior pulmonary vein. There is an anterior segmental branch that frequently arises direct- The vessel is mobilized on its superior and inferior aspects with ly opposite the superior segmental branch to the lower lobe, as well blunt and sharp dissection, encircled with blunt dissection, and li- as a more distally situated lingular branch.These vessels should be gated and divided with either clamps or a vascular stapler.With the identified, individually ligated, and divided. Not infrequently, mul- lung retracted superiorly, the inferior pulmonary vein is dissected tiple posterior apical branches are encountered; in fact, as many as as in a right lower lobectomy [see Figure 5]. Once isolated, this vein seven vessels supplying the left upper lobe may be identified. is also ligated and divided as previously described (see above). Next, the whole lung is retracted caudally and inferiorly to With the lung retracted anteriorly, attention is directed toward expose the aortic arch. A large arterial branch supplying the api- the right mainstem bronchus [see Figure 3]. The subcarinal lymph coposterior aspect of the upper lobe is usually encountered. nodes are mobilized, and the bronchial artery on the posterior Although the superior and posterior aspects of this artery are eas- medial aspect of the right mainstem bronchus is controlled. The ily dissected, the anterior aspect is frequently obscured by an api- remaining peribronchial tissues are then mobilized distally with cal branch of the superior pulmonary vein; division of this venous blunt and sharp dissection. To avoid leaving a long bronchial branch may improve exposure and facilitate control of the artery. stump, exposure of the bronchus to within 1 cm of the carina is Once the artery is encircled, it is ligated and divided. To prevent advisable. avulsion of this vessel from the main pulmonary artery, care must The bronchus can be closed with a TA stapler loaded with 4.8 be taken not to exert excessive traction on the lung. mm staples. The staples should be oriented so as to allow good With the lung now retracted posteriorly, the mediastinal pleura approximation of the anterior and posterior membranous walls. If is opened parallel to and posterior to the course of the phrenic
  8. 8. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 8 Upper-Lobe Left Pulmonary the lingula and the lower lobe is completed with serial application Bronchus Artery of GIA staplers [see Figure 9].The left upper lobe bronchus is encir- cled and either clamped or controlled with a TA stapler.To prevent inadvertent injury, the pulmonary artery branches to the lower lobe should be gently retracted posteriorly during stapler placement. With the stapler applied (or the clamp in place), the anesthesiolo- gist ventilates the left lung to verify that air is flowing freely to the entire left lower lobe. Once unobstructed airflow is confirmed, the stapler is fired and the bronchus divided. Left Lower Lobectomy As in a left upper lobectomy, dissection begins within the inter- lobar fissure. The pulmonary artery is identified, and the branches to the upper and lower lobes are dissected [see Figure 7].The supe- rior segmental artery is encircled first and is ligated and divided; not uncommonly, there are actually two separate superior segmental arteries. The basilar segmental arteries are then encircled distal to the origin of the lingular artery. These vessels are also ligated and divided, with care taken not to encroach on the blood flow to the lingula. The lung is rotated superiorly to expose the inferior pulmonary vein. As in a right lower lobectomy, the vein is encircled by dissect- ing first on its anterior surface with the lung rotated posteriorly, Figure 9 Left upper lobectomy. Shown is the surgeon’s view of then on its posterior surface with the lung rotated anteriorly [see the left fissure after division of the upper-lobe arteries. Care Figure 10]. Once the vein is encircled, it is ligated and divided. should be taken not to injure the pulmonary artery inadvertently Attention is then redirected toward the interlobar fissure, and when applying a stapler. the left lower lobe bronchus is identified [see Figure 11].The origin of the bronchus is cleared by sweeping nodal tissue distally with blunt and sharp dissection. The upper-lobe branches of the pul- nerve [see Figure 8].The superior pulmonary vein can then be iden- monary artery are gently retracted superiorly to allow placement of tified easily. If the apical branch was not previously ligated, the sur- a TA stapler on the bronchus. With the stapler applied, the anes- geon should make every effort not to damage the pulmonary artery thesiologist ventilates the left lung to confirm the adequacy of air- branches that lie posterior to this portion of the vein.The majority flow to the upper lobe. The stapler is fired, and the bronchus is of the superior pulmonary vein lies anterior to the left upper lobe divided distal to the staple line. bronchus. Once this vein is encircled, it is ligated and divided. Attention is then redirected toward the fissure, and the peri- Left Pneumonectomy bronchial nodal tissue surrounding the left upper lobe bronchus is The initial steps of a left pneumonectomy are similar to those of swept distally with blunt and sharp dissection.The fissure between a left upper lobectomy.The lung is retracted caudally, and the pleu- Upper-Lobe Bronchus Left Pulmonary Artery Figure 10 Left lower lobecto- my. Shown is the surgeon’s view of the left inferior pul- monary vein. The left side, unlike the right side, affords only limited access to the sub- carinal space. However, the length of the inferior pul- monary vein outside the peri- cardium is greater on the left side than on the right. Lower-Lobe Bronchus Inferior Pulmonary Vein Esophagus
  9. 9. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 9 Left Upper Left Mainstem divided first to facilitate arterial exposure (see below). Lobe Bronchus Once the pulmonary artery is encircled, the vessel can be ligat- ed and divided. My preferred method is to use an endovascular GIA stapler, the advantages of which include its rapidity of use, its consistently reproducible results, and its ability to control the vessel along a broad surface. Mass ligation is not advisable, because the risk of dislocation of the tie is too great. When the length of exposed artery is too short or a stapler cannot be placed safely, the surgeon may apply vascular clamps to the proximal and distal portions of the vessel instead. Once the vessel is divided, the proximal end may be oversewn with a continuous polypropylene suture. If additional vessel length is required because of the presence of a proximal tumor, the ligamentum arteriosum may be divided.The recurrent laryngeal nerve should be identified and preserved. In dividing the left pulmonary artery proximal to the ligamentum arteriosum, care should be taken not to narrow the main pul- monary artery and thereby reduce right-side blood flow. For max- imal safety, systemic blood pressures and oxygenation should be evaluated for 1 to 2 minutes after application of the clamp or sta- pler but before ligation. Figure 11 Left lower lobectomy. Shown is the surgeon’s view of With the lung retracted posteriorly, the pleura is incised posteri- the left fissure after division of the lower-lobe vessels. In this pro- or to the course of the phrenic nerve, and the superior pulmonary cedure, a single oblique transection of the entire left lower-lobe vein is identified [see Figure 8].The vein is encircled with blunt dis- bronchus can be employed without any concern that a proximal bronchus will be compromised; this step would not be feasible in section, then ligated and divided. As noted (see above), the apical a right lower lobectomy, in that the right middle-lobe bronchus branch usually travels across the apical branch of the pulmonary arises from the bronchus intermedius. artery, and care should be taken not to injure this vessel during dissection. The lung is then retracted superiorly to expose the inferior pul- ra is incised along the course of the aortic arch [see Figure 7]. The monary vein. Dissection is performed on the anterior and posteri- superior and posterior surfaces of the pulmonary artery are dissect- or aspects of the inferior pulmonary vein, and blunt dissection is ed as it enters the thorax under the aortic arch. Once the perivas- used to achieve complete encirclement of the vein [see Figure 10], cular space is entered, the entire vessel can usually be encircled with which is ligated and divided. blunt dissection. If the superior pulmonary vein’s apical branch lim- Next, the lung is retracted anteriorly and superiorly. Complete its access to the anterior surface of the pulmonary artery, the branch dissection of the subcarinal lymph nodes is performed, facilitated may be ligated and divided first to improve exposure of the artery; by division of one or two pulmonary branches of the left vagus alternatively, the superior pulmonary vein itself may be ligated and nerve and both bronchial arteries. Gentle traction is applied in Stumps of Left Pulmonary Artery Left Inferior Figure 12 Left pneumonectomy. Pulmonary Shown is the surgeon’s view of the Vein posterior left hilum. The carina is located deep under the aortic arch. A left-side double-lumen tube or bronchial blocker may have to be withdrawn to afford better exposure of the proximal left mainstem bronchus. The ori- Aorta entation of the superior pul- monary vein and the pulmonary artery (anterior and superior to the bronchus, respectively) should Pericardium Stump of be noted. Left Mainstem Bronchus Left Vagus Nerve Left Superior Pulmonary Vein
  10. 10. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 4 THORAX 14 PULMONARY RESECTION — 10 conjunction with blunt dissection to allow encirclement of the the bronchus is divided distal to the staple line. proximal left mainstem bronchus [see Figure 12]. An effort should Frequently, the position of the bronchial stump under the aor- be made to encircle the bronchus within 1 cm of the carina. A TA tic arch and deep within the mediastinum renders coverage of the stapler is then passed around the left mainstem bronchus and stump unnecessary. If the surgeon is concerned about possible applied at this point. If excessive traction is required to achieve stump dehiscence (e.g., in a patient who has undergone high-dose this placement, the bronchial stump can be left slightly longer: 1 preoperative radiotherapy), coverage with a flap from the pericar- to 1.5 cm, as measured from the carina. The stapler is fired, and dial fat pad or intercostal muscle is appropriate. Selected Reading Fell SC, Kirby TJ: Technical aspects of lobectomy. tions. General Thoracic Surgery, 6th ed. Shields TW, Pearson FG, Cooper JD, Deslauriers J, et al, Eds. General Thoracic Surgery, 6th ed. Shields TW, LoCicero J, Ponn RB, et al, Eds. Lippincott Williams & Churchill Livingstone, Philadelphia, 2002, p 974 LoCicero J, Ponn RB, et al, Eds. Lippincott Williams & Wilkins, Philadelphia, 2005, p 470 Wilkins, Philadelphia, 2005, p 433 Martini N, Ginsberg RJ: Lobectomy. Thoracic Surgery, Hood RM: Techniques in General Thoracic Surgery, 2nd ed. Pearson FG, Cooper JD, Deslauriers J, et al, 2nd ed. Lea & Febiger, Philadelphia, 1993 Eds. Churchill Livingstone, Philadelphia, 2002, p 981 Acknowledgment Kirby TJ, Fell SC: Pneumonectomy and its modifica- Waters PF: Pneumonectomy.Thoracic Surgery, 2nd ed. Figures 1, 2, and 4 through 12 Alice Y. Chen.