All bronchoplastic procedures include reconstruction of the airway. (The techniques of airway surgery are reviewed.) Familiarity with the parenchymal anatomy is a necessity. Although there are standards regarding the conduct of these operations, consensus is lacking regarding the specific suture technique or type of suture one should use, and personal preference prevails with regard to these details.
Finally, my personal preference is to buttress all bronchoplasty sites. Transposed tissue pedicles include thymic (epicardial) fat pad, pleura, pericardium, and occasionally, muscle flap. The most common muscle pedicle is the intercostals. Although some do not recommend wrapping the flap circumferentially around the anastomosis out of concern for heterotopic ossification from retained periosteum, a recent series did not find this to be a problem. The serratus anterior can be used as a buttress for reconstructions after induction chemoradiation therapy.
The most basic bronchoplastic technique is hand-sewn closure of a bronchial stump divided close to its takeoff from the mainstem bronchus or trachea. 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. 66-1). This maneuver is predicated on having enough uninvolved membranous airway to allow the repair. As with most of these procedures, accurate intraoperative margin pathology must be available. Some short bronchial stumps can be closed by simple anteroposterior reapproximation (Fig. 66-2). The surgeon must assess the quality of the tissue and have a sense of the tension under which the bronchus is plicated. Closely spacing the interrupted sutures helps to distribute tension but will not compensate for a gross error in judgment. 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 very 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 excellent. Rarely should a primary closure be attempted after wedge bronchotomy (Fig. 66-3). Although this type of reconstruction often can be performed with minimal tension, the resulting kink in the airway can become a mechanical and functional obstruction postoperatively.
Bronchoplastic removal (A) and closure (B) of a bronchial stump using a flap of the membranous airway.
Alternative technique for bronchoplastic removal (A) and closure (B) of a short bronchial stump involving simple suture reapproximation.
Primary closure of a wedge bronchotomy (A) can result in severe angulation of the airway and mechanical obstruction (B).
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 a true resection and reconstruction of the bronchus itself. Regardless, the technique of airway surgery is similar.
Important factors to consider specific to these operations are (1) will the planned 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. Finally, can the patient tolerate a bilobectomy or pneumonectomy if the planned bronchoplastic resection cannot be completed safely, as would be the case if the pulmonary artery or mainstem bronchus were irreparably injured?
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 main stem bronchi and carina. Unfortunately, mediastinal adhesions that form after a remote mediastinoscopy will complicate airway mobilization. Intraoperative flexible bronchoscopy after induction of anesthesia is mandatory in every patient to confirm the location and extent of the pathology.
Right Upper Lobe Sleeve Resection
The right upper lobe sleeve resection is the most common and straightforward sleeve resection one can perform. A left-sided double-lumen tube is placed during induction of anesthesia, and the patient is positioned for a posterolateral thoracotomy. Muscle-sparing techniques can be used to enter the hemithorax at the fourth or fifth interspace. Some trapezius and posterior latissimus muscles 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 back 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, etc.). 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 then are freed from loose fibroareolar attachments to the pulmonary artery. The ongoing pulmonary artery is distracted from the airway with gentle traction inferiorly and anteriorly.
Umbilical tapes are passed around the proximal right mainstem bronchus and the bronchus intermedius, and the proximal airway should be completely mobile (Fig. 66-4). Unless disease extends close to the carina, the proximal right mainstem bronchus should not be skeletonized, and the azygos vein seldom needs to be divided. The airway is transected in a perpendicular fashion proximally and distally (Fig. 66-4, 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 principle. 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 still will be tethered by its lateral vascular attachments.
Right upper lobe sleeve resection. After the anterior aspect of the right mainstem bronchus and bronchus intermedius are mobilized from the pulmonary artery, the artery is distracted with gentle traction inferiorly and anteriorly. Umbilical tapes are passed around the proximal right mainstem bronchus and the bronchus intermedius. (Inset) The airway is transected proximally and distally.
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 primarily by avoiding the complex array of multiple untied sutures used for the interrupted anastomosis. Before beginning the anastomosis, the cut ends of the airway are oriented properly and tested for a tension-free coaptation. Stay sutures placed at the membranous-cartilaginous junctions facilitate coaptation (Fig. 66-5). Because of the posterolateral view, it is easy to become disoriented because the airway will be rotated almost perpendicular to its native position during the reconstruction. Palpation permits immediate 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 polypropylene) 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 mediolateral fashion in both directions. The entire membranous airway is 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 first from medial to lateral; this avoids injury to the pulmonary artery. Thereafter, the posterior membranous portion can be closed as well.
Running anastomosis technique. A. Stay sutures are placed at the membranous-cartilaginous junctions of both proximal and distal airways for orientation purposes. B. Running suture technique is begun on the medial aspect of the anastomosis and proceeds laterally (in both directions) to coapt the entire membranous component and the medial half of the cartilaginous airway. C. The membranous suture is secured to a lateral anchor stitch, and this second suture is run medially toward the apex of the cartilaginous airway.
Interrupted suture technique is also an option (particularly for a size mismatch), but again, the organization of the multiple sutures becomes cumbersome. When there is a size discrepancy between the right mainstem bronchus and the bronchus intermedius, a telescoping anastomosis is performed with the membranous portion run and the anterior cartilaginous airway interrupted.
Once the bronchoplasty is completed, the anastomosis is leak tested at 25–30 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.
Most patients should be extubated in the OR. The effectiveness of steroids postoperatively is unproved, but I favor an induction dose.9
Early postoperative bronchoscopy is recommended only for symptoms or air leak not explained by a parenchymal source. Mild pulmonary dysfunction from ipsilateral pulmonary edema is common. Chest tube management is identical to that in nonbronchoplastic resections. Bronchoscopy is performed at 6 weeks to assess airway healing. Unless abnormal findings are encountered, bronchoscopies are scheduled at yearly intervals, up to 5 years, for cancer surveillance.
Resection of any other lobe can be combined with a bronchoplastic procedure (Fig. 66-6). While the principles of reconstruction are the same for all, there are slight differences in the anatomic concerns of each.
Diagrams demonstrating other possible bronchoplastic resections.
For tumors 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. 66-7). 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. Technical problems can arise when the airway is scalloped to accommodate an inferior takeoff of the right middle lobe during a sleeve resection of the lobe. B. Sacrifice of the superior segment may be a better alternative.
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. 66-8). 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. 66-9).
If possible, leaving a flange of airway around the middle lobe orifice of intermediate size is a better match and simplifies reconstruction after right lower lobe sleeve resection.
Plication of the membranous airway also can reduce a size mismatch.
Left-sided resections are more 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 are most critical. For an isolated proximal left main stem tumor, the bronchoplastic procedure also can 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, an isolated left main stem bronchial tumor can be approached from a right thoracotomy with good exposure posterior to the carina.