75: Sleeve Resection/Bronchoplasty for Lung Cancer

The importance of parenchymal preservation during pulmonary surgery was realized over 50 years ago when descriptions of bronchial resection and reconstruction were first published.^1–3 Since then, considerable technical refinement and anatomic insight have expanded indications for lung-sparing operations. Bronchoplastic resections form one category of these procedures with a unique set of indications. These operations are technically more demanding than standard anatomic pulmonary resections, although, the additional time spent performing these procedures is justly rewarded in considerable functional lung preservation.

The terms bronchoplasty and bronchoplastic resection have been applied to a wide variety of operations of main or lobar bronchi. The operations usually involve a concomitant parenchymal resection; resection and reconstruction of the bronchus alone is quite rare. Bronchoplasty refers to resection and reconstruction of a lobar bronchial orifice (e.g., right upper lobe) without removing a segment of main bronchus. This is in contradistinction to a “sleeve” resection in which a circumferential portion (or sleeve) of a central bronchus is included as part of the operation. Because of the gaps that sleeve resections create in the target airways, release maneuvers (to reduce tension on the anastomosis) are usually necessary.

The standard indication for bronchoplastic resection is an endobronchial lesion emanating from either the main bronchus itself or a lobar bronchus with main bronchus encroachment. The extent of the diseased area must allow for safe reconstruction when margins are considered. Etiology is often a low-grade neoplasm such as typical carcinoid or mucoepidermoid cancer⁴ or, rarely, isolated bronchial stenosis secondary to granulomatous disease, trauma, caustic injury, foreign body, or benign neoplasm.^5,6 Bronchoplastic resections can be applied to more invasive cancers, that is, non–small-cell lung cancer (NSCLC) or metastases, when trying to spare lung parenchyma in a patient with marginal pulmonary function. While lung is preserved, oncologic principles, namely, achieving a complete resection (including a negative margin), must not be compromised.⁷ Positive margins are not an acceptable alternative to complete resection.

The issue of N1/N2 lymph node involvement clearly complicates the decision to proceed with a lung-sparing bronchoplastic resection versus pneumonectomy or bilobectomy. To date, there are no data to suggest that larger parenchymal resections provide a higher cure rate for stage II or stage III lung cancer. Therefore, bronchoplasty can be performed for stage II or stage III lung cancer as long as a complete resection can be obtained. In addition, data from several European studies of neoadjuvant chemotherapy and/or radiation therapy suggest that a bronchoplastic resection can be performed without additional morbidity. Of note, radiation therapy completed more than 3 months before the resection considerably increases the technical difficulty and should be considered high risk. Few definitive contraindications exist for bronchoplastic or sleeve resection techniques as long as the patient's performance status allows. One should know in advance whether pneumonectomy is an option in case the sleeve is technically not feasible.

Bronchoscopy is universally required for operative planning. Flexible video bronchoscopy offers a slightly less morbid alternative for diagnosis and initial palliative therapy than does traditional rigid bronchoscopy, though both are acceptable methods to access and treat the central airways. For patients presenting with obstructing pneumonia, airway patency should be restored using endobronchial techniques (i.e., laser, cautery, pneumatic or rigid dilation); any infection should be effectively drained and treated before proceeding with a planned resection.

Noninvasive imaging includes chest computed tomography scan (CT) and, for NSCLC, a PET scan. To complete the staging process, mediastinoscopy should be performed for all lung cancers before attempting a sleeve. If performed at the same setting as the planned resection, mediastinoscopy can be used to mobilize the mainstem bronchi and trachea and serve as an important release strategy. If N2 lymph node involvement is found (for patients with lung cancer), the patient is usually offered induction therapy before the resection or treated definitively with chemoradiation.

Epidural analgesia is recommended to optimize pain control and pulmonary toilet. Ipsilateral lung isolation usually is obtained with a contralateral double-lumen tube and not a single-lumen tube with bronchial blocker.

All bronchoplastic procedures include reconstruction of the airway. Familiarity with parenchymal and vascular anatomy is essential. No consensus exists regarding the optimal suture type or technique one should use, and personal preference prevails with regard to these details. We favor the use of monofilament material.

Finally, my personal preference is to buttress all bronchoplasty reconstructions. Transposed tissue pedicles include thymic (epicardial) fat pad, pleura, pericardium, and occasionally, muscle flap. The most common muscle pedicle is adjacent intercostal, though some do not recommend wrapping this type of flap circumferentially for anecdotal concern of heterotopic ossification from retained periosteum. Serratus anterior can also be used as a buttress for reconstructions after induction chemoradiation therapy.

Bronchotomy Closure

The most basic bronchoplastic technique is hand-sewn closure of a bronchial stump divided close to its takeoff from the mainstem bronchus. Often, a flap of membranous airway can be turned back over the open stump and sewn in place with interrupted 4-0 monofilament suture (Fig. 75-1). This maneuver is predicated on having enough uninvolved membranous airway. As with all of these procedures, intraoperative frozen section analysis of the margins must be performed. Some short bronchial stumps can be closed by simple anteroposterior reapproximation (Fig. 75-2). The surgeon must assess the quality of the tissue and have a sense of the tension under which the bronchus is reapproximated. Closely spacing the interrupted sutures helps to distribute tension but will not compensate for a marked mismatch. Airway compliance should be assessed carefully before considering a bronchotomy closure. In older patients, calcium within the anterior bronchial rings can make simple closure of a tight bronchial stump more risky, and surprisingly, the more complex sleeve resection is often the safer operation. Conversely, in younger patients, even if a small amount of the mainstem bronchus is plicated during the closure, results are typically excellent. Only rarely should primary closure be attempted after wedge bronchotomy (Fig. 75-3). Although this type of reconstruction can be performed with minimal tension, the resulting kink in the airway can lead to obstruction postoperatively. Intraoperative bronchoscopy is an important tool to assess the geometry of the airway after reconstruction and judge the suitability of the reconstructed anatomy.

Bronchial Sleeve Resection

Most bronchial sleeve resections occur in the context of parenchymal (lobar) resection. Rarely, pathology isolated to the left mainstem bronchus or bronchus intermedius mandates an isolated resection of the airway alone.

Important factors to consider are (1) will the operation result in a complete resection, (2) can the repair be constructed tension-free, and (3) if not, what are the fallback options? To this end, the etiology of the disease becomes important. Specifically, for lung cancer, accurate staging is mandatory. Also, a history of prior chest surgery makes complete mobilization of the lung more difficult, and a previous coronary artery bypass may complicate a hilar release. A mediastinoscopy performed several weeks before will make it difficult to mobilize the carina and distal trachea for right-sided resections. Finally, can the patient tolerate a bilobectomy or pneumonectomy if the planned bronchoplastic resection cannot be completed safely or with an adequate margin?

Any lobar resection can be accompanied by a sleeve of resected bronchus. Left-sided resections are more challenging because the aortic arch and heart tend to limit exposure. Mediastinoscopy is useful not only from a cancer staging standpoint but also in mobilizing the proximal left and right mainstem bronchi and carina. The surgeon must confirm the anatomy of the airway lesion with bronchoscopy.

Right Upper Lobe Sleeve Resection

Right upper lobe sleeve resection is the most common and straightforward sleeve resection. A left-sided double-lumen tube is placed during induction of anesthesia, and the patient is positioned for a lateral thoracotomy. Muscle-sparing techniques can be used to enter the hemithorax at the fourth or fifth interspace. Some trapezius and posterior latissimus musculature may require division if the fourth interspace is entered. An intercostal muscle pedicle can be harvested for later use.

The lung must be fully mobilized. The anterior and posterior pleural reflections over the hilum are divided. The inferior pulmonary ligament is divided up to the inferior pulmonary vein. The chest should be surveyed carefully to ensure that no obvious contraindications for the procedure exist (e.g., pleural metastases, interlobar spread). Separation of the pulmonary arterial and venous supplies to the upper lobe and completion of the horizontal fissure and cephalad aspect of the major fissure follow.

Once the lobe is isolated, the subcarinal space is dissected until the pericardium and carina are easily visualized. This entails mobilizing the esophagus from the airway. The subcarinal lymph node packet is removed. The anterior aspect of the right mainstem bronchus and bronchus intermedius are freed from loose fibroareolar attachments of the pulmonary artery. The ongoing pulmonary artery is distracted from the airway with gentle traction inferiorly and anteriorly. Finally, the distal trachea is gently mobilized while preserving the lateral vascular stalks.

Umbilical tapes are passed around the proximal right mainstem bronchus and the bronchus intermedius (Fig. 75-4). Unless disease extends close to the carina, the proximal right mainstem bronchus should not be skeletonized. The azygos vein seldom needs to be divided. The airway is transected in a perpendicular fashion proximally and distally (Fig. 75-4, inset). The specimen is sent for margin analysis. Determining the exact location for airway division can be aided by bronchoscopy. To reduce tension on the bronchial anastomosis, proximal and distal release maneuvers are performed. Standard proximal release maneuvers involve dissection of the anterior and, if necessary, posterior mainstem bronchus and trachea from investing fibroalveolar tissues. Since most of the proximal airway vascular supply is segmental and delivered through lateral pedicles, the airway is mobilized circumferentially above and below these lateral attachments without compromising the blood supply. Extensive, complete circumferential dissection results in ischemia at the anastomosis. For right-sided bronchoplastic resections, the left mainstem bronchus is easily mobilized by adhering to the same principles. The right mainstem bronchus, however, cannot be easily dissected for left-sided resections. Little is gained by extended (≥5 cm) anterior and posterior mobilization because the proximal airway will remain tethered by its lateral vascular attachments.

For distal release, in addition to completely dividing the inferior pulmonary ligament, a full hilar release may be required (Fig. 75-5). This entails the circumferential division of the pericardium investing the right hilum. An incision in the pericardium is made anteriorly over the superior pulmonary vein and carried out in a caudad fashion until the base of the inferior pulmonary vein has been exposed. The pericardial division is then reflected posteriorly (and superiorly) around the posterior aspect of the left atrium in a C-loop toward where the pulmonary artery exits the pericardium. This maneuver fully mobilizes the hilum and should markedly reduce the tension on the airway anastomosis.

If the resection margins are free of disease, a few choices for reconstructing the airway can be considered. Interrupted suture technique has been demonstrated to be effective and reliable. For anastomoses of well-matched bronchi, a continuous suture technique simplifies the reconstruction. Before beginning the anastomosis, the cut ends of the airway are oriented (Fig. 75-6) and tested for a tension-free coaptation. Stay sutures placed at the membranous–cartilaginous junction facilitate coaptation (Fig. 75-7). It is easy to become disoriented because if viewed from posterolateral vantage point, the airway will be rotated almost perpendicular to its native position during the reconstruction. Palpation permits identification of the membranous airway and should be repeated frequently if orientation becomes unclear during the anastomosis. Once proper alignment is established, a running suture (usually 4-0 monofilament) is begun at the medial membranous–cartilaginous junction (which will project as the most posterior aspect of the anastomosis from the posterolateral thoracotomy vantage). The anastomosis proceeds in a medial–lateral fashion in both directions. The entire membranous airway can be reapproximated with this running suture and tied to a second anchoring suture placed at the lateral cartilaginous–membranous junction. The lateral (corner) stitch then is run medially (to reapproximate the cartilaginous airway) toward the apex of the airway, where it is tied to the running suture sewn in the other direction. Alternatively, the cartilaginous portion is closed with a running suture performed from medial to lateral. The posterior membranous portion can be closed as described above. All knots are kept on the outside of the lumen.

Interrupted suture technique is also an option (particularly for a size mismatch), but the organization of the sutures can become cumbersome and frustrating. When there is a size discrepancy between the right mainstem bronchus and the bronchus intermedius, a telescoping anastomosis can be performed with the membranous portion run and the anterior cartilaginous airway interrupted.

Once the bronchoplasty is completed, the anastomosis is leak tested at 25 to 30 cm H₂O of pressure. No air leak can be tolerated from the reconstructed airway. It is customary to buttress the anastomosis with a pedicled flap of autologous tissue (e.g., thymic fat pad, pleura, or intercostal muscle), although this is of no proven benefit to airway healing. Importantly, buttressing is not the solution for lack of pneumostasis of the bronchoplasty and will not salvage a poorly constructed anastomosis. Buttressing does, however, separate the anastomosis from the pulmonary artery. This is especially important if bronchial and arterial sleeve resections are performed concomitantly.

Patients should be extubated in the OR. The effectiveness of steroids postoperatively is unproved.⁸ Although induction steroids have the theoretical benefit of diminishing edema and maximizing airway patency.

Early postoperative bronchoscopy is rarely required but recommended for unexpected airway leak. Mild pulmonary dysfunction from ipsilateral pulmonary edema is common. Chest tube management is identical to that in nonbronchoplastic resections. We perform bronchoscopy at 6 weeks to assess airway healing. Some surgeons perform bronchoscopies, scheduled at yearly intervals, up to 5 years, for cancer surveillance.

Other Sleeve Resections

Resection of any other lobe can be combined with a bronchoplastic procedure (Fig. 75-8). Although the principles of reconstruction are the same for all, tension-free anastomosis with negative margins, there are slight differences in the anatomic concerns of each.

For tumors of the orifice of the right middle lobe bronchus (usually carcinoid), the position of the involved bronchus and tumor in relation to the superior segmental and composite basilar bronchi becomes important. It can become a very tedious, often treacherous, undertaking to attempt reconstruction if the lower lobe bronchus is cut back to the orifices of the segmental bronchi. Scalloping the distal airway in an attempt to save the superior segment complicates and jeopardizes the repair (Fig. 75-9). Because this maneuver produces a patulous membranous airway, reanastomosis can result in stenosis of the superior segment orifice and chronic atelectasis of the associated lung. In these instances, it is often better to resect the superior segment and create a more linear sewing margin.

A right lower lobe sleeve resection is complicated primarily by the size discrepancy between the remaining middle bronchus and the bronchus intermedius. Depending on tumor location, a flange of tissue around the middle lobe orifice can be saved and will be a much better size match for reconstruction (Fig. 75-10). When a size mismatch cannot be avoided, a telescoping technique of interrupted sutures can be used. Occasionally, the membranous portion of the bronchus intermedius can be plicated to improve sizing issues (Fig. 75-11).

Left-sided resections are relatively rare and more difficult. The problem lies with exposure. The left pulmonary artery (anteriorly) and the aortic arch (posteriorly) limit access to the left mainstem bronchus from the left posterolateral approach. Extensive mobilization of the aorta often is required, and because of the difficult exposure, interrupted suture technique is the best option for reconstruction. For resection and reconstruction of the left mainstem bronchus, these issues become critical. For an isolated proximal left mainstem tumor, the bronchoplastic procedure can also be performed through a sternotomy, with or without cardiopulmonary bypass. The left mainstem bronchus is located from this exposure through the posterior pericardium just cephalad to the main pulmonary artery and to the left of the ascending aorta. Injury of the left recurrent nerve can complicate any left-sided bronchoplastic procedure. Alternatively, a proximal left mainstem bronchial tumor can be approached from a right posterolateral thoracotomy with good exposure to the posterior aspect of the carina and proximal left mainstem. Airway control in this setting can be tedious with the need for cross-table ventilation and a brief ECMO run can facilitate the procedure.

Pulmonary Vascular Sleeve Resections

Sleeve resection of the airway spares lung parenchyma and vascular sleeve of the pulmonary artery can be used similarly when pathology dictates. This might require resection of either a noncircumferential part (arterioplasty) or complete segment of the pulmonary artery (sleeve resection) to be resected. To perform a pulmonary arterial sleeve resection, classic vascular surgical principles of proximal and distal control are required. Proximal control of the main pulmonary artery is best obtained in an intrapericardial fashion, while distal control may be obtained by clamping or looping the distal margin at the appropriate extrapericardial level. Low-dose systemic heparinization before clamping is recommended (2000–3000 units).⁹

A simple arterioplasty might suffice if only a small segment of the pulmonary artery is involved and the resulting defect in the artery can be repaired primarily without narrowing the outflow by greater than 10% to 20%. However, if the lumen compromise is greater, a patch angioplasty will be required. A variety of grafts can be used including native (our preference) or bovine pericardium, decellularized collagen matrices, or autologous vein (e.g., azygos). It is important to avoid any undue laxity in the patch to minimize kinking of the vessel when lung is reexpanded.

When tumors involve a significant portion of the circumference of the pulmonary artery, a segmental resection should be employed. Following resection, a primary anastomosis can be performed with a running 5-0 monofilament nonabsorbable suture. As with any vascular anastomosis, de-airing maneuvers should be performed. Should the resection of a long segment of the artery be necessary, pericardial conduits can be constructed.¹⁰ If a concomitant bronchial sleeve resection is also performed, the arterial anastomosis is usually performed to reperfuse the lung, but care must be taken to avoid traumatizing the newly repaired vessel during the airway reconstruction. Routine use of tissue buttresses is advocated in these cases to minimize development of a life-threatening bronchovascular fistula. We do not reverse heparin at the end of the case and favor low-dose aspirin on the first postoperative day along with standard subcutaneous heparin as venous thromboembolism prophylaxis.

Segmental resection of a pulmonary vein is seldom, if ever, indicated, and its reconstruction is highly susceptible to thrombosis and life-threatening thromboembolism.

Lung tumors that are amenable to sleeve resection usually present with an endobronchial component that result in some degree of obstructive physiology with dependent alveolar hypoxia and vasoconstriction. Once the lesion is removed and the remaining lung parenchyma is allowed to fully ventilate, the V–Q mismatch within the preserved parenchyma is typically improved over the subsequent 3 to 8 months.¹¹ There may also be an increase in FEV1, perhaps attributable to compensatory hyperinflation of the remaining ispsilateral lung. Though there are no randomized data available, several large case-control studies (and meta-analyses) suggest improved survival and lower postoperative mortality of sleeve lobectomy over pneumonectomy.¹² Local recurrence is minimal at 1% and bronchial complication rate is observed in only 1% to 2% of patients when performed by experienced surgeons. Importantly, stage-adjusted 5-year survival is comparable to that seen after standard lobectomy.^13–16 Though there has been some concern that neoadjuvant therapy might increase anastomotic complications, this has not been borne out.^17,18

Although more complex than standard parenchymal resections, bronchoplastic procedures provide lung-sparing alternatives to pneumonectomy or bilobectomy without compromised cancer-related outcomes. Patient selection is critical, but in appropriately screened patient populations, and when performed by experienced surgeons, excellent outcomes can be achieved.

I agree that in the current era, the use of sleeve resections as popularized by Rendina et al.^8,10 should exceed the use of pneumonectomy. If mediastinoscopy is to be done (which I do routinely), one should schedule the subsequent resection in less than 2 weeks to avoid development of significant scarring. I routinely use an intercostal muscle flap wrapped around the anastomosis. In addition, when performing a bronchial and vascular sleeve, the muscle flap helps protect the pulmonary artery from erosion by the prolene/PDS knots.