At Washington University, our preferred approach for bilateral LVRS is via median sternotomy. It provides excellent exposure and increased flexibility with a minimum of morbidity. Median sternotomy avoids injury to chest wall muscles and intercostal nerves both from the operative approach and from the chest tubes, which are brought out below the costal arch. However, other groups have obtained similar results using a bilateral video-assisted thoracic surgery (VATS) approach.
Many patients with severe emphysema have a significant element of chronic bronchitis with increased sputum production. After induction of anesthesia, a single-lumen tube is placed, and flexible bronchoscopy is carried out to suction secretions and obtain a specimen for culture and for STAT Gram stain. If thick, tenacious secretions are encountered, a minitracheostomy may be inserted at the end of the operative procedure to facilitate postoperative pulmonary toilet. After bronchoscopy, the endotracheal tube is replaced with a left-sided double-lumen tube.
Ventilation to both lungs is briefly suspended just before sternal division. A rolled sponge is advanced upward behind the sternum from the subxiphoid position and used to sweep the pleura away from the retrosternal area (Fig. 87-2). This keeps the mediastinal pleura intact on both sides as the sternum is divided. While ventilation is suspended, the sternum is divided with a sternal saw. The right mediastinal pleura is incised sharply, taking care to visualize and avoid injury to the phrenic nerve near the apex of the chest. Ventilation is maintained to the right lung until just prior to entrance into the pleural space because this facilitates assessment of the degree of emphysematous damage in various portions of the lung. Demarcation of the fissures or lack thereof is best seen when the lung is fully inflated. Ventilation to the right lung then is suspended while ventilation to the left lung is continued. Care is taken by the anesthesiologist to avoid overinflating the left lung, and airway pressures generally are restricted to 15–20 cm H2O pressure. Hypercapnia occasionally occurs, but this is usually well tolerated.
The pleura is swept off the underside of the sternum before median sternotomy to prevent injury to the emphysematous lungs.
Most candidates for LVRS have upper lobe predominant disease. Several minutes after ventilation is suspended to the right lung, the right middle and lower lobes are usually well deflated and become progressively atelectatic. The pulmonary ligament is divided, and adhesions are taken down under direct vision (Fig. 87-3). Dense adhesions are not common but may be encountered if there have been prior episodes of pneumonia. We occasionally use an extrapleural dissection adjacent to adhesions to avoid injuring the fragile lung parenchyma.
As a consequence of the asymmetric emphysema, the right upper lobe remains hyperinflated despite single-lung ventilation to the left lung.
For upper lobe disease, 70–80% of the right upper lobe is excised with multiple applications of a linear stapler buttressed with strips of bovine pericardium. It is often easier to apply the stapler to the deflated lung, and this can be accomplished rapidly by using the cautery to fenestrate the apex of the right upper lobe (Fig. 87-4). The marked collateral ventilation leads to prompt collapse. A long, straight intestinal clamp can be applied to the lung to create a linear “crush” mark prior to application of the linear stapler (Fig. 87-5). We currently staple straight across the upper lobe beginning medially above the hilum and ending up just above the upper extent of the oblique fissure. Care should be taken to avoid crossing the fissure because this may damage the superior segment of the lower lobe (Fig. 87-6). In addition, stapling across the fissure may tether the superior segment of the lower lobe to the remaining upper lobe and prevent the superior segment from fully expanding and filling the apex of the chest. After the first two applications of the linear stapler, it may be awkward to insert the stapler into the chest again to complete the excision. An endoscopic stapler fitted with pericardial strips is well suited to reach deeply into the chest to complete the excision. We prefer to use a single line of excision to remove most of the right upper lobe rather than multiple excisions. It is important to remember that the goal is to adequately reduce volume, not to remove all areas of diseased lung.
A cautery can be used to facilitate deflation of the upper lobe. This is performed on an area that will be excised and makes it easier to apply the mechanical staplers.
The lung is marked with an atraumatic clamp to guide the generous wedge resection.
The wedge is performed with a buttressed stapler with all due care to avoid injury of the superior segment of the lower lobe.
Occasionally, the apex of the upper lobe will be densely adherent to the apex of the chest and to the superior mediastinum. In such cases, it may be easier to first transect the upper lobe as described earlier before attempting to dissect the apical and mediastinal adhesions (Fig. 87-7). Once the transection has been accomplished, the specimen can be detached more easily from the chest wall and mediastinum using blunt or sharp dissection, cautery, or even a linear stapler, leaving a small remnant of the lung attached to the mediastinum, if necessary. It is imperative to avoid injury to the phrenic nerves, a complication that will severely compromise postoperative recovery.
It is sometimes easier to perform the wedge resection before separating the pleural adhesions. If there are dense mediastinal adhesions, the phrenic nerve must be identified and protected. A paralyzed diaphragm is catastrophic in these patients. If the adhesions are so dense that the phrenic nerve is not well identified, it is better to leave a little lung parenchyma attached to the mediastinal pleura.
After the upper lobe resection, the chest is partially filled with warm saline, and the lung is gently inflated. Air leaks at this time are unusual, but the reexpanded remaining lung often does not completely fill the apex of the chest. We have explored the use of a pleural tent in this situation but now reserve it for rare instances, in particular when the remaining lung is still tethered in the chest by virtue of adhesions to the chest wall or diaphragm. It has not been our practice to perform mechanical or talc pleurodesis, even if the patient is not a potential candidate for subsequent lung transplantation.
Two chest tubes are placed in the pleural space and brought out near the midline through small subcostal stab wounds. The posterior tube is brought across the dome of the diaphragm and halfway up the posterior chest. The anterior tube is brought to the apex of the chest near the mediastinum.
Ventilation is shifted from the left lung to the right lung, and the mediastinal pleura is then opened on the left side. Particular care should be taken to visualize the phrenic nerve and avoid injury to it when opening the upper portion of the mediastinal pleura because the anatomic location of the left phrenic nerve makes it vulnerable to injury. With upper lobe predominant disease, the goal is to excise the superior subdivision of the left upper lobe, leaving the lingula intact, because this is usually much less diseased (Fig. 87-8). The left pulmonary ligament usually is divided, but this requires displacement of the heart. If exposure is limited, the ligament is left intact, and adhesions between the left lower lobe and the diaphragm are taken down. Unlike the anatomic situation on the right side, the superior segment of the left lower lobe usually easily reaches to the apex of the chest, even without division of the pulmonary ligament.
A generous left upper lobe wedge is shown. Most of the lingula is left in place.
The upper half to two-thirds of the left upper lobe is excised with multiple applications of the linear GIA stapler. This is facilitated by deflating the apex of the upper lobe with cautery puncture. The long, straight intestinal clamp is often useful in helping to identify and demarcate the proposed line of excision. The line of excision usually is parallel to the oblique fissure separating the upper and lower lobes. Similar to the right side, care is taken to avoid stapling across the fissure into the superior segment of the left upper lobe.
After left upper lobe excision, the lung is reinflated and inspected for air leaks. Two chest tubes are placed, and the mediastinal pleuras are closed on both sides. A small window of pleura is left open inferiorly to allow drainage of any mediastinal fluid collection into the pleural spaces. Mediastinal chest tubes are not necessary. Many volume-reduction patients are on steroids before surgery. To prevent wound dehiscence, we use an overlapping figure-of-eight stainless steel wire closure of the sternum. Virtually all patients are extubated in the OR. If excessive secretions are present after the procedure or during the initial bronchoscopy, a 4-mm-diameter minitracheostomy is inserted at the time of extubation to facilitate aggressive pulmonary toilet.
Pain control is essential to ensure adequate postoperative respiratory function. An epidural catheter is placed, and it is imperative to confirm that a bilateral block has been established before beginning the procedure. Although this is not absolutely necessary, we use fluoroscopy to allow placement of the catheter at the tip of T4. During induction, hypotension can result from air trapping as well as pneumothorax. Air trapping leading to “pulmonary tamponade” is treated by removing the patient from the ventilator and allowing him or her to exhale to the atmosphere. Bronchodilators and prolonged exhalation times are also helpful, but it is often necessary to remove the patient from the ventilator during exhalation.
During the procedure, our anesthesiologists avoid narcotics and limit the use of benzodiazepines to limit long-term respiratory depression. The inspiratory pressures are limited to 15–20 cm H2O during one-lung ventilation to avoid excessive pressure on the fresh staple lines. Most of these patients have an element of CO2 retention, and permissive hypercapnia is tolerated. During emergence, patients may be drowsy, and it is not unusual to have initial PaCO2 values as high as 90 mm Hg. This is transient and will come down as the patient receives nebulizers and chest physical therapy in the recovery room.