ENDOTRACHEAL INTUBATION
Endotracheal
intubation is a lifesaving procedure that requires familiarity with anatomy,
physiology, pharmacology, and the necessary equipment required to perform the
procedure.
Choice of the correct size of endotracheal tube is fundamental. The average man will accept a cuffed tube with an inner diameter of 8.0 or 8.5 mm. For women, the tube diameter is 0.5 to 1.0 mm smaller. Smaller tubes have more resistance to airflow and may not allow passage of a bronchoscope, but larger tubes may increase injury to the glottis and lower airway.
TRACHEAL RESECTION AND ANASTOMOSIS
Tracheal stenosis can be idiopathic but is most commonly the result of prior intubation or tracheostomy. Common areas of stenosis were previously located in the mid-trachea related to high-pressure, low-volume endotracheal tube cuffs; however, contemporary endotracheal appliances have low-pressure cuffs. Today stenotic lesions are typically found in the proximal or subglottic trachea at the site of a prior stoma. Mid- to distal tracheal resections are more likely performed as therapy for benign or malignant airway tumors. In most cases of symptom-producing stenosis of the trachea, conservative therapy, consisting of repeated dilatations, is either contraindicated or has proven to be ineffective. Consequently, surgical correction is necessary. The procedure of choice is resection of the stenotic tracheal segment with primary reconstruction via an end-to-end anastomosis (see illustration).
REMOVAL OF MEDIASTINAL TUMORS
Tumors of the mediastinum are a challenging group both diagnostically and in terms of treatment. A host of pathologic entities is involved, and for many of these, surgical excision is the treatment of choice. Recognition and identification of mediastinal abnormalities are almost always based on chest radiographs. Although the radiologic appearance is sometimes characteristic or (rarely) pathognomonic, most often it is the location within the mediastinum that is most influential in correct diagnostic interpretation.
SUBLOBAR RESECTION AND SURGICAL LUNG BIOPSY
Resection of lung tissue anatomically less than a lobe is carried out for localized lesions such as benign tumors, granulomas, tuberculous foci, bronchiectasis, metastatic cancers, and others and to obtain tissue specimens required for the diagnosis of diffuse pulmonary disease processes. Recent evidence suggests anatomic segmentectomy may provide survival equivalent to lobectomy for small (2 cm) primary lung cancers in the absence of regional node involvement.
LOBECTOMY
Lobectomy is a more difficult procedure to perform than pneumonectomy, particularly in the presence of chronic inflammatory changes or where tumor (or involved lymph nodes) involves the lobar hilum. Not only must the critical lobar structures be individually identified and controlled by the surgeon, but the remaining structures must be painstakingly protected and preserved. Incomplete fissures may add to the problem, and the surgeon must possess a precise knowledge of hilar anatomy and common anomalies.
PNEUMONECTOMY
Pneumonectomy was first successfully performed in 1933 by Evarts Graham. The procedure was carried out for bronchogenic carcinoma in a fellow physician, James Gilmore, who eventually outlived his surgeon. The event is a milestone in surgical history. The technique of pneumonectomy has been improved and standardized in the intervening years, and the results are quite gratifying when the operation is carefully performed in appropriately selected cases. Current indications are chiefly as an operation for cure for lung cancer (usually centrally located) or for a destroyed lung as a result of infection or trauma. Palliative pneumonectomy is generally not warranted unless it is directed at alleviation of sepsis or control of recurrent hemorrhage. Before embarking upon resection of an entire lung, the surgeon must have a histologic diagnosis and a full assessment of the patient’s cardiopulmonary reserve; little is gained if the pneumonectomized patient survives but has severe respiratory disability.
VIDEO-ASSISTED THORACOSCOPIC SURGERY
Video-assisted thoracoscopic surgery (VATS) has become a common tool for thoracic surgeons. It is useful in the evaluation and management of patients with pleural disease, benign and malignant pulmonary parenchymal neoplasms or diseases, mediastinal masses or adenopathy, and esophageal pathology and for resection of posterior mediastinal neurogenic tumors or conditions responsive to sympathectomy. A VATS operation is defined by use of two or more port incisions and video display of the involved hemithorax on operating room monitors, and it does not involve rib spreading. Most standard thoracic surgical instruments have been modified for thoracoscopic surgery.
LUNG VOLUME REDUCTION SURGERY
The goal of lung volume reduction surgery (LVRS) is to safely palliate dyspnea in patients with emphysema. Successful LVRS demands attention to the details of patient selection, preoperative preparation, intraoperative anesthetic and surgical technique, and multidisciplinary postoperative care. Expertise and effective communication among pulmonary medicine, thoracic surgery, thoracic anesthesia, pain management services, critical care medicine, respiratory therapy, and rehabilitation medicine departments are vital components to any LVRS program. In experienced centers, bilateral approaches yield nearly twice the physiologic benefit to unilateral LVRS without adversely affecting operative morbidity or mortality. Current practice favors stapled bilateral resection over plication or laser ablation to achieve lung volume reduction.
LUNG TRANSPLANTATION
Clinical lung transplantation was first attempted in the 1960s, but little success was achieved until the availability of more effective immunosuppressive drugs (cyclosporine) and improved surgical techniques in the early 1980s. The annual number of lung transplant procedures has increased steadily from fewer than 100 per year in the 1980s to more than 2700 transplants reported by 150 worldwide transplant centers in 2007. Lung transplantation is now an accepted therapy for all forms of advanced lung disease.
MORBIDITY OF
ENDOTRACHEAL INTUBATION AND TRACHEOSTOMY
Nasotracheal tubes may be more easily inserted, less easily dislodged, and sometimes better tolerated than orotracheal tubes. However, they can cause nasal necrosis and maxillary sinusitis. “Blind insertion” may result in vocal cord trauma, which can be minimized by visualization, as with oral intubation. Nasotracheal tubes have small lumina, making suctioning and weaning from mechanical ventilation difficult. Orotracheal tubes are larger and more readily permit suctioning or bronchoscopy than nasotracheal tubes. However, they are less comfortable, more easily dislodged, and can be kinked or damaged by the patient’s teeth.
