INDICATIONS/CONTRAINDICATIONS

Carinal resection and reconstruction without pulmonary resection that involves restitution of the carina by suturing the right and left mainstem bronchi together and approximating these to the end of the distal trachea is termed neocarinal reconstruction. This method of reconstruction was one of the first approaches used for tumors involving the distal trachea and tracheal carina. However, in the past it was felt that this technique was less frequently applicable for reconstruction following carinal resection because after approximation of the right and left mainstem bronchi the neocarina is fixed in the middle mediastinum by the aortic arch, making approximation to the trachea challenging. In the modern era, with earlier identification of neoplastic lesions involving solely the tracheal carina, which do not require resection of significant lengths of trachea or mainstem bronchi, neocarinal reconstruction is performed more frequently (Fig. 42.1).

Carinal resection with neocarinal reconstruction is applicable most commonly to low-grade malignant or benign airway tumors and occasionally for very well localized early nonsmall cell lung cancers. Inflammatory lesions in the distal trachea or mainstem bronchi are rarely localized enough to be managed using this type of reconstruction. While the absolute limits of airway resection that can be managed by near carinal reconstruction are variable, certainly more than 3 to 4 cm of proximal tracheal involvement and more than 1 to 1.5 cm of either mainstem bronchial involvement would preclude this option for airway reconstruction.

PREOPERATIVE PLANNING

All patients who are candidates for carinal resection and possible neocarinal reconstruction should undergo a complete preoperative physiologic evaluation. Assessment of pulmonary and cardiac function is important given the potential duration and physiologic stress related to the operative procedure. Complete pulmonary function tests including spirometry lung volumes and diffusion capacity are mandatory. However, with a localized lesion that does not require prior resection, it is infrequent that pulmonary function parameters would limit the patient’s candidacy for resection. On the other hand, a prolonged operative procedure with intermittent ventilation and possible hypoxia increases the risk of cardiac stress and thus a low threshold for cardiac stress testing is indicated for patients with risk factors for coronary artery disease.

Preoperative imaging should include a chest radiograph and a chest CT scan. If the patient has a seemingly localized nonsmall cell lung cancer, accurate staging including positron emission tomography (PET) scanning and brain MRI imaging is mandatory. Some controversy exists about the validity of classifying mediastinal lymph nodes involved by a carinal carcinoma as N2 disease. However, in most cases if there is histologically confirmed metastasis to level 4 or level 2 mediastinal lymph nodes, carinal resection is contraindicated.

Bronchoscopy is an essential and integral part of the preoperative evaluation. Rigid bronchoscopy is the only methodology that allows accurate measurements of the extent of airway involvement. The feasibility of neocarinal reconstruction following carinal resection can only be determined by this modality. In addition, accurate assessment of the histology of the tumor is required. Adenoid cystic carcinomas typically have submucosal or perineural extension to a degree far beyond the gross mucosal disease. Thus, the likelihood of neocarinal resection is extremely limited for this type of low-grade airway malignancy. Rigid bronchoscopy also allows for debulking of central tumors and potential relief of obstructive pneumonitis to optimize the patient’s preoperative status.

SURGERY

Anesthetic Technique

Ideally, anesthesia for carinal resection and reconstruction should allow extubation at the end of the procedure. The goals of maintaining adequate anesthesia and gas exchange while allowing for surgical exposure require close cooperation between the anesthesiologist and the surgeon. In these cases, an extra-long, flexible, armored single-lumen endotracheal tube is used. This is placed in the trachea proximal to the carina at the beginning of the operative procedure. After dissection and isolation of the carinal structures, depending upon the operative approach, transection of the mainstem bronchi is usually performed prior to transection of the trachea. This allows intubation of the left mainstem bronchus across the operative field for maintenance of ventilation and anesthesia during the remainder of the resection and in the initial part of the reconstruction. Once the anastomotic sutures are placed and the initial approximation of the airway is completed, gentle hand ventilation through the proximal endotracheal tube, which has been guided carefully across the anastomosis by the surgeon into the left mainstem bronchus or, alternatively, ventilation with the endotracheal tube proximal to the anastomosis are two options to be used while the anastomotic sutures are being tied. At times, alternative techniques may be required. High-frequency jet ventilation of the right lung concomitant with ventilation of the left lung using an endotracheal tube passed across the operative field may be useful to maintain oxygenation. In occasional circumstances, independent lung ventilation with cross-field ventilation of both mainstem bronchi may be required to provide both adequate ventilation and oxygenation. A final alternative, extracorporeal membrane oxygenation (ECMO) may be employed, but is usually avoided because of concerns of pulmonary hemorrhage resulting from intraoperative manipulation of the lung.

Surgical Approach

Right posterolateral thoracotomy, median sternotomy, or right anterolateral thoracotomy can be used to approach the tracheal carina. The right posterolateral thoracotomy through the fourth or fifth interspace provides optimal exposure of the carinal structures, particularly if there is significant pleural or posterior mediastinal disease or tumor extension. This approach, however, does not provide optimal access for mobilization of the proximal airway or for the possibility of left hilar release, although the latter is an uncommon requirement for carinal resection without lung resection. Finally, visualization using the right posterolateral thoracotomy incision may be hampered due to ongoing ventilation of the right lung, although in most cases gentle retraction on the right lung, even with active expansion of that lung, will allow adequate exposure of the carina. Median sternotomy provides optimal anterior exposure of the tracheal carina in addition to providing the potential for both laryngeal and bilateral hilar release, if required. In practice, however, for neocarinal reconstruction bilateral hilar release is rarely necessary. Median sternotomy does eliminate the problem of a partially ventilated lung in the operative field. Right anterolateral thoracotomy can be used for carinal exposure, but in the setting of carinal resection without lung resection, may not offer any specific advantage over posterolateral thoracotomy or median sternotomy.

Stay updated, free articles. Join our Telegram channel

Join