Tumors invading the tracheobronchial angle or the carina represent a challenge due to the complexity of airway reconstruction and management. The first historical report of a right tracheal sleeve pneumonectomy comes from Abbott  who, in 1950, reported surgical resection of the carina, tracheal wall and contralateral bronchial wall in patients undergoing right pneumonectomy. In 1959 Gibbon  described a patient who survived for 6 months after a resection of the distal trachea during right pneumonectomy and anastomosis of the left bronchus to the residual trachea. In Europe, sleeve pneumonectomy was reported for the first time by Mathey  in 1966, who presented two cases of right sleeve pneumonectomy among 20 tracheal and tracheobronchial resections performed over a period of 15 years. In 1972 Jensik  published the first large series of 17 cases of tracheal sleeve pneumonectomy for advanced bronchial carcinoma, with two intraoperative deaths and three long-term survivors.
Other series focusing on carinal resection were published by different authors in the 1980s [5-9]), however early and long-term results remained unsatisfactory. Only in recent years, some authors [10-15] reported large series with low operative mortality and acceptable survival rates. The standardization of anastomotic techniques and the availability of different ventilation modalities were recognized as determinants of the improved perioperative outcome, with marked reduction in mortality (30% before 1990) and morbidity rates. Furthermore, the increased long-term survival over time was probably due to the better selection of candidates for surgery.
Carinal resection is a complex and aggressive procedure for the treatment of bronchial tumors involving the carina, the tracheo-bronchial angle or the distal portion of the trachea (Figure 1). The airway is reconstructed by anastomosis of the opposite main bronchus (tracheal sleeve pneumonectomy) or both bronchi (isolated carinal resection) to the lower trachea (Figure 2). The most common indication for a sleeve pneumonectomy is a tumor involving the origin of right main bronchus or extending into the lower trachea. Left sleeve pneumonectomy is rarely indicated since the left main bronchus is considerably longer than the right one and, in the case of carinal infiltration, tumor usually invades the structures in the subaortic space as well, which frequently implies inoperability. An isolated carinal resection and reconstruction may be applicable for centrally located, low grade and small tumors of the carina not extending so far to the main bronchi. Carinal resection represents a challenge for thoracic surgeons and anesthesiologists related to demanding intraoperative airway management, the technique of anatomic reconstruction and the risk of significant postoperative morbidity, mortality and poor long-term outcome .
All patients scheduled to undergo carinal resection should receive a complete medical evaluation, especially focused on cardio-pulmonary function, comorbidity and concurrent medications. Particular attention should be given to the presence of long-term steroid therapy, diabetes or prior mediastinal irradiation. Pulmonary function is assessed using basal and exercise stress testing and arterial blood gas analysis. For those patients with an FEV1 of less than 2 L a ventilation–perfusion scan should be obtained. A predicted postoperative FEV1 greater than 1 L is used as a cutoff to determine functional operability.
Cardiac function is assessed based on a physical examination, electrocardiography, and transthoracic echocardiography in all patients. Radiological work-up includes standard chest X-ray, total body CT-scan, bone scintigraphy and PET scan, where indicated. All patients should be submitted to rigid bronchoscopy (Figure 3) and sometimes to virtual bronchoscopy (Figure 4) to precisely assess the extent of invasion and the required resection. Mediastinoscopy (in case of malignant tumors), performed at the time of planned resection, may be useful to discover potentially involved lymph nodes, to evaluate the mediastinal and extraluminal spread of the neoplasm and to dissect the pretracheal plane, enhancing the mobility of upper trachea and reducing the risk of recurrent laryngeal nerve injury.
Under general anesthesia, the patient is ventilated through a left-sided double-lumen tube that is pulled back into the trachea during the carinal resection. The anastomotic step can be performed during ventilation with a separate sterile endotracheal tube across the operative field, through a high frequency jet ventilation (HFJV) catheter (Figure 5) or using a combined mode. The use of HFJV permits an optimal ventilation and oxygenation, allowing an easier placement of single stitches with a greater accuracy. Moreover, the tying of sutures is facilitated by using a small bore catheter, eliminating the need for intermittent withdrawal and reinsertion of the endotracheal tube. After completion of planned reconstruction, the endotracheal tube is first positioned above the anastomosis to test for air leakage, then is advanced beyond the line of suture and ventilation can be delivered in a standard fashion. In our experience, cardiopulmonary bypass is usually not necessary as support during this kind of surgery. However, in case of left tracheal sleeve pneumonectomy, the use of CPB should be indicated for some reasons: important traction on vascular structures is frequently necessary to perform anastomoses and ventilation of the right lung may be difficult. Moreover, the use of CPB does not appear to increase the risk of cancer dissemination.
The surgical approach may vary according to the type of planned resection [16-20]. There are a variety of reconstructive possibilities for carinal resection. Choosing among them depends on the patient’s specific anatomy and disease. The surgical approach for most carinal resections is a right posterolateral thoracotomy. Median sternotomy and clamshell incision for isolated carinal resection and for left carinal pneumonectomy may be useful. A median sternotomy provides excellent exposure of the carina, facilitating the anastomosis and resulting in less pain and ventilatory restriction than a posterolateral thoracotomy. In addition, these approaches allow performance of bilateral hilar release as well as better control of relevant blood vessels.
Disadvantages of the sternotomy approach include difficulties in freeing parieto-pleural adhesions as well as risk of hemodynamic instability during mobilization of the heart. For these reasons, in case of a left carinal pneumonectomy, some authors [21-22] have suggested a two-staged procedure with a standard left pneumonectomy through a postero-lateral thoracotomy, leaving the infiltrated bronchial stump as a first step, followed by carinal resection 3 to 5 weeks later by a right-sided approach.
Access to the carina is performed through a right postero-lateral thoracotomy, via the fourth or fifth intercostal space. The azygos vein is divided and the mediastinal pleura is opened to expose and encircle the trachea, the carina, the right and left main bronchus. Lateral dissection of the trachea should be limited to preserve blood supply and to avoid injury to the laryngeal recurrent nerve. Before starting the resection and reconstruction procedure, regardless of the level and the kind of anastomosis, different release maneuvers can be accomplished to reduce tension: division of inferior pulmonary ligament, retrograde mediastinoscopy, hilar release with U-shaped pericardial opening (Video 1), and mobilization of the left main bronchus by gentle blunt dissection from the aortic arch and surrounding tissue. Laryngeal release is rarely required (except in case of extended tracheal involvement) and should be avoided for the risk of potential aspiration.
When a right pneumonectomy has been performed, the trachea is transected at least 1 cm above the tumor, the left main bronchus is incised usually one ring below the carina in healthy tissue and the carina is removed (Video 2). Frozen section is imperative to exclude infiltration of the site of tracheo-bronchial division. Two traction sutures (2-0 Vicryl; Ethicon, Inc, Somerville, NJ) are fixed in the mid-lateral position on the trachea proximally and on the left main bronchus distally (Video 3). These traction sutures will be tied together after the completion of the anastomosis to reduce the tension. The end-to-end airway anastomosis is started with retraction of the tube into the trachea and the high-frequency jet-ventilation (HFJV) catheter is passed through the endotracheal tube and positioned in the left main bronchus (Video 4). A mild flexion of the neck, that allows the upper trachea to be pulled down into the mediastinum, is applied before starting the anastomosis. After the trachea and bronchi are anastomosed, the jet catheter is withdrawn, and the patient can be ventilated through the endotracheal tube left in place above the anastomosis. After this maneuver, three interrupted 3-0 polyglactin stitches (Vicryl; Ethicon, Inc, Somerville, NJ) are placed on the deepest part, at the level of the left membranous–cartilaginous angle and tied with the knots outside the lumen (Video 5). Several interrupted 3-0 polyglactin stitches are then placed in the remaining part of the anastomosis, about 2 to 3 mm from each other, and are tied after all of them have been placed to correct for size discrepancies (Video 6). The stitches applied on the membranous portion are tied at the end to avoid any traction and potential tears (Video 7).
When the suture lines are completed and tested for air leak, the anastomosis can be covered with a circumferential flap of viable tissue (e.g. pericardium, pericardial fat pad, thymic tissue, intercostals muscle or parietal pleura flap) for the purpose of buttressing.
At the end of the procedure, the anastomosis is checked using bronchoscopy, and secretions are removed from the airways. The patient may be extubated in the operating room.
In isolated carinal resection and reconstruction, applicable for centrally located, low grade and small tumors (Video 8), the right and left main bronchi can be medially sutured to create a new carina, that is subsequently anastomosed to the distal trachea (Figure 2C and Video 9). A less common technique provides the resection of the carina followed by an end-to-end anastomosis between the left main bronchus and the trachea, followed by anastomosis of the right main bronchus to the lateral, cartilaginous wall of the trachea, paying attention to stay at least 2 cm above the first anastomosis (Figure 6). When more advanced tracheal involvement is present, two alternative techniques may be used to avoid excessive tension: an end-to-end anastomosis between the right main bronchus and the trachea, followed by anastomosis of the left main bronchus to the lateral, cartilaginous wall of the bronchus intermedius or an end-to-end anastomosis between the left main bronchus and the trachea, followed by anastomosis of the right main bronchus to the lateral, cartilaginous wall of the left main bronchus (Figure 7). In all of cases a wide hilar release is mandatory to reduce tension on the anastomoses.
Left tracheal sleeve pneumonectomy is a rare operation in the surgical series reported and many controversies ride on which is the better surgical approach. A one- or a two-staged operation may be planned; the one-stage approach is performed by a clamshell incision or a median sternotomy with or without anterior left thoracotomy . The procedure carries on with exposure of lower trachea and carina through the transpericardial way. After left pneumonectomy and carinal resection the anastomosis between the lower trachea and the right main bronchus is completed in the same fashion as standard right sleeve pneumonectomy (Video 10). The two-staged procedure can be done in different ways: standard left pneumonectomy by left thoracotomy followed by carinal resection and anastomosis between trachea and right main bronchus with a standard right-sided approach; carinal resection and reconstruction through a right thoracotomy followed by a minimally invasive, video-assisted left pneumonectomy .
Tracheal sleeve lobectomy is a challenging operation usually required for management of neoplasms involving the trachea or the carina and the proximal right main bronchus extending to the origin of the right upper bronchus (Figure 8). In cases of contraindication for sleeve pneumonectomy or in case of low-grade neoplasm, the carina, right main bronchus, and right upper lobe may be removed. The reconstruction consists of an end-to-end anastomosis of the left main bronchus to the trachea, and creation of a secondary end-to-side anastomosis of the bronchus intermedius either to the trachea (Figure 9) or more frequently to the left main bronchus (Figure 10), because elevating the bronchus intermedius to the side of the trachea often creates excessive tension, with high risk of fistula or stenosis.
Reconstruction of the airways begins with an end-to-end anastomosis between the left main bronchus and the trachea in a manner similar to sleeve pneumonectomy (Video 11). Two pedicled flaps of the posterior pericardium (overlying the left atrium and posterior to the SVC) are mobilized and one is used to cover the primary anastomosis (Video 12).
For the anastomosis of the bronchus intermedius on the trachea a window in the trachea (Video 13) or in the left main bronchus is created; this opening should be completely within the cartilaginous part and also generous (to avoid malacia and stenosis), removing at least 2 cartilaginous rings. In case of tracheal reconstruction the window must be performed at least 2 cm above the primary anastomosis to avoid necrosis of the intervening part of the trachea. The end-to-side anastomosis is performed with single stitches starting from the cartilagineous part (Video 14); then the second pericardial flap is passed to surround the anastomosis (Video 15). Bronchoscopic evaluation of the anastomoses is mandatory to follow the correct healing (Video 16).
Tumors involving the carina or right tracheo-bronchial angle may involve the superior vena cava (SVC), either directly or by nodal extracapsular infiltration. In these cases, a combined surgical procedure is mandatory and represents a challenging operation because in addition to the technical complexity, each procedure requires contradictory intraoperative fluid management. In the last decade some authors [25-27] demonstrated the feasibility of either partial or complete resection of SVC in association with sleeve pneumonectomy with acceptable early and long-term results in case of T4 tumors, while mediastinal nodal involvement negatively affected the prognosis. We do not consider direct invasion of the SVC by primary tumor a contraindication for sleeve pneumonectomy, but we exclude from surgery those patients with SVC involvement by metastatic paratracheal lymph-nodes.
The primary lung tumor usually infiltrates the lateral wall of the SVC requiring in most cases simply direct suture of the SVC or patch reconstruction (Video 17) . The indication for complete SVC replacement is limited to the case of an infiltration of more than 50% of the circumference of the vessel. The SVC can usually be replaced by using a polytetrafluoroethylene (PTFE) prosthesis (Video 18) , an heterologous (bovine) pericardial prosthesis  or a tube constructed from autologous pericardium (Figure 11) . Before clamping, intravenous sodium heparin 5000 UI, Solumedrol 4 mg and Mannitol 250 ml are given to prevent any brain damage.
The reported surgical mortality ranges from 4% to 16%, with morbidity rates between 11.3% and 51%. The most common surgical and postoperative complications include anastomotic leakage (from 1.8% to 25.1%), acute respiratory distress syndrome (ARDS), contralateral pulmonary edema, pneumonia, empyema, cardiac herniation, supraventricular arrhythmia, recurrent nerve palsy and chylothorax.
The short- and long- term results in the literature are summarized in Table 1.
|Author||Year||Number of patients||Mortality (%)||Morbidity (%)||Anastomotic complications (%)||5-year survival (%)|
|De Perrot ||2006||119||7.6||47||10||44|
The most important factors affecting the long-term outcome are the completeness of resection and the absence of nodal involvement.
In experienced centers resection of carina may be a safe approach in highly selected patients, with acceptable morbidity and mortality and good long-term survival.
Publication Date: 24-Aug-2012
Last Modified: 2-Oct-2012