Sequelae and complications of pneumonectomy

INTRODUCTION — Pneumonectomy, or surgical removal of an entire lung, is performed most frequently for management of bronchogenic carcinoma. In this setting, pneumonectomy is required over lesser resection, such as lobectomy, when the tumor is located in a main stem bronchus or the proximal bronchus intermedius, adjacent to the right upper lobe orifice, or when the tumor extends across a major fissure [1]. Pneumonectomy may rarely be performed for pulmonary metastases or for a variety of benign diseases, such as inflammatory lung disease (eg, pulmonary tuberculosis, fungal infections, and bronchiectasis), traumatic lung injury, congenital lung disease, and bronchial obstruction with a destroyed lung [2].

Pneumonectomy is associated with a variety of reasonably predictable anatomic changes, significant decrements in pulmonary function, and a number of potential complications that involve the respiratory system, the cardiovascular system, and the pleural space [3] (table 1). The preoperative evaluation of the patient being considered for pneumonectomy, and clinical issues relating to the outcome, sequelae, and complications following pneumonectomy will be reviewed here. A general discussion of preoperative evaluation prior to lung resection surgery is presented separately. (See "Preoperative physiologic pulmonary evaluation for lung resection".)

EXPECTED CHANGES POSTPNEUMONECTOMY

Changes in postpneumonectomy space — Immediately following pneumonectomy, air fills the space previously occupied by the lung (ie, the postpneumonectomy space [PPS]). Unlike the situation with most other forms of thoracic surgery, a chest tube is not inserted following pneumonectomy, and the air is therefore not evacuated. Over time, a number of changes result in a decrease in the size of the PPS, including elevation of the hemidiaphragm, hyperinflation of the remaining lung, and shifting of the mediastinum towards the PPS. At the same time, there is progressive resorption of air in the PPS and replacement with fluid.

Chest radiographic findings immediately after surgery demonstrate the trachea to be midline and the PPS to be filled with air (image 1A-B). Within 24 hours the ipsilateral hemidiaphragm becomes slightly elevated, the mediastinum shifts slightly towards the PPS, and fluid starts accumulating in the PPS. As a general rule, fluid accumulates at a rate of one to two intercostal spaces per day in the immediate postoperative period. The median time to 70 percent opacification (fluid at the level of the main carina on an upright chest radiograph) is three days [4]. As pleural pressure increases, the rate of fluid accumulation decreases, and after two weeks, 80 to 90 percent of the PPS is filled with fluid.

By chest radiograph, complete opacification of the hemithorax after pneumonectomy takes an average of approximately four months, with a range from three weeks to seven months [5]. Unexpectedly rapid accumulation of fluid into the PPS in the immediate postoperative period should raise concerns for hemorrhage into the PPS, infection of the PPS, or the development of a chylothorax. While the chest radiograph typically demonstrates complete opacification of the hemithorax, chest CT scans demonstrate that only a small fraction of patients have obliteration of their PPS, with most patients having residual fluid and/or air [6]. The length of time following pneumonectomy does not correlate with complete obliteration of the space nor the amount of fluid remaining in the space.

The location of vital organs (including the heart and great vessels, liver, and spleen) changes significantly following pneumonectomy as a consequence of mediastinal shift and elevation of the hemidiaphragm (image 2A-C) [3]. After left pneumonectomy, the heart rotates counterclockwise into the vacant left pleural space. Following right pneumonectomy, the heart shifts into the vacant right pleural space [7]. Extreme care must be taken prior to inserting a needle or chest tube into the PPS, due to the risk of injury to vital organs that have shifted position following the surgery [8]. We recommend an imaging study such as ultrasound or CT scan to help locate vital organs prior to any attempt to drain the PPS.

Some of the anatomic changes in the thorax following pneumonectomy can result in complications. As an example, postpneumonectomy syndrome, a rare complication resulting in large airway obstruction due to narrowing and stretching of the main bronchus, is a direct result of severe shifting of the mediastinum after pneumonectomy (see 'Postpneumonectomy syndrome' below). In addition, residual fluid in the PPS can serve as a nidus for infection and result in the development of a postpneumonectomy space empyema.

Postoperative pulmonary function — Pulmonary function predictably decreases following pneumonectomy, but many of the changes are less than anticipated for the amount of lung tissue that has been removed. (See "Preoperative physiologic pulmonary evaluation for lung resection".)

Specific changes include the following [3,9]:

●Postpneumonectomy lung volumes fall, but typically less than expected for removal of approximately 50 percent of the original lung tissue. This is especially true for residual volume and is a consequence of overexpansion of the remaining lung. However, despite this overexpansion, there is no pathological evidence of emphysema in the remaining lung.

●Forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) usually decrease by less than 50 percent.

●Diffusing capacity for carbon monoxide (DLCO) also decreases by less than 50 percent and is usually normal when corrected for lung volume.

●Lung compliance decreases, airway resistance increases, and dead space may either increase or decrease.

●Arterial oxygen saturation, PO₂, and PCO₂ at rest do not change in those patients with little or no disease in the remaining lung.

There is little subsequent decline in lung function that can be attributed to pneumonectomy beyond one year after the procedure. Long-term studies have demonstrated minimal further change in FEV₁ up to 20 years after pneumonectomy, with annual decrements in FEV₁ that are 3 to 4 mL per year, which is less than that expected for the general population [10]. Patients with adequate lung function post pneumonectomy have been reported to tolerate other major surgeries including cardiovascular bypass, cardiac valve replacement, esophagectomy, and contralateral lung resection [11,12].

Postoperative cardiovascular function — Studies have addressed changes in cardiovascular function after lung resection, with conflicting results [7,13-15].

Right ventricular ejection fraction decreases, right ventricular end-diastolic volume increases, and left ventricular function does not change, according to one prospective cohort study that evaluated 31 patients before and two days after pneumonectomy using echocardiography [15].

In contrast, another study used dynamic magnetic resonance imaging to assess the cardiac function of 15 patients five years after pneumonectomy [7]. Right ventricular end-diastolic volume was low and left ventricular function was normal among patients who underwent right pneumonectomy, while right ventricular end-diastolic volume was normal and left ventricular function was low among patients who underwent left pneumonectomy [7]. In all patients, resting heart rate was elevated and stroke volume was low.

The reason for the conflicting results is uncertain but could be due to the different durations since the pneumonectomy or the different imaging techniques used. As long as the remaining lung is relatively normal, there is no significant change in resting values of systolic pulmonary artery pressure, pulmonary vascular resistance index, or central venous pressure after lung resection [14]. Maximal oxygen consumption decreases between 17 and 28 percent after pneumonectomy [16,17].

PULMONARY COMPLICATIONS — Potential pulmonary complications following pneumonectomy include postpneumonectomy pulmonary edema, postpneumonectomy syndrome, and intraoperative spillage of material into the remaining lung.

Pulmonary edema — Postpneumonectomy pulmonary edema occurs with an overall frequency of 2 to 5 percent, and it is three times more common following right than left pneumonectomy. Although the pathogenesis is unknown and probably multifactorial, it is thought to represent a form of the acute respiratory distress syndrome (ARDS). It does not appear to be a complication of cardiac dysfunction, sepsis, pneumonia, or aspiration. (See "Acute respiratory distress syndrome: Epidemiology, pathophysiology, pathology, and etiology in adults".)

Postpneumonectomy pulmonary edema is characterized clinically by respiratory distress and hypoxemia within 72 hours of surgery. A single intraoperative dose of Solu-Medrol (250 mg administered just prior to ligation of the pulmonary artery) may decrease the risk of developing this complication [18]. When it occurs, mortality rates exceed 50 percent. One review of postpneumonectomy pulmonary edema suggests that the underlying mechanism of injury may be due to high inspired oxygen concentrations, associated with single-lung ventilation, or ischemic and reperfusion injury to the remaining lung [19].

Postpneumonectomy syndrome — Postpneumonectomy syndrome reflects extrinsic compression of the distal trachea and mainstem bronchus due to shifting of the mediastinum and hyperinflation of the remaining lung (image 3) [20,21]. It occurs more than six months following surgery and has even been reported 35 years after surgery. It is more common in patients who undergo surgery in childhood and is almost exclusively seen after right pneumonectomy [22-24].

The syndrome is characterized by development of progressive dyspnea, cough, inspiratory stridor, and recurrent pneumonia in patients at least six months after surgery. It can be fatal if left untreated. Treatment consists of surgical repositioning of the mediastinum and filling of the postpneumonectomy space (PPS) with a non-absorbable material; saline breast implants have been used successfully for this purpose [21,23,25].

Two rare variants of PPS have been described. One occurs when the esophagus becomes compressed, resulting in dysphagia [26]. The other occurs due to compression of the remaining pulmonary vein resulting in dyspnea [27]. Surgical repositioning of the mediastinum improves symptoms.

Intraoperative spillage — In patients undergoing pneumonectomy for suppurative lung disease, purulent material can spill into the unoperated lung at the time of surgery. Respiratory failure and death have been reported from this complication. Prevention of intraoperative spillage is therefore critically important and includes such measures as endobronchial separation with a double-lumen endotracheal tube, prone positioning, and perioperative bronchoscopy to remove secretions.

PLEURAL SPACE COMPLICATIONS — Several complications affecting the pleural space, either the postpneumonectomy space or the contralateral pleural space, are considered here. The main categories of pleural space complication include infection, fistula formation, bleeding, chylothorax, and contralateral pneumothorax.

Postpneumonectomy empyema — Empyema in the postpneumonectomy space complicates approximately 5 percent of pneumonectomies. Early empyema occurs within 10 to 14 days of surgery and is commonly associated with a bronchopleural fistula. Late empyema, in which infection is most often acquired via a hematogenous route, occurs more than three months after pneumonectomy and has been reported up to 40 years following surgery. The most common organisms causing postpneumonectomy empyema are Staphylococcus aureus and Pseudomonas aeruginosa. Almost 50 percent of cases of both early and late empyemas are polymicrobial. (See "Epidemiology, clinical presentation, and diagnostic evaluation of parapneumonic effusion and empyema in adults".)

Early empyema frequently presents with fever and occasionally expectoration of purulent sputum. The infection may rarely "necessitate," ie, spread directly through the chest wall and drain through the overlying skin. Late empyema frequently presents with nonspecific symptoms such as flu-like symptoms, weight loss, low grade fever, and anorexia.

Chest radiographs may be helpful in suggesting the diagnosis. Specific radiographic findings include a shift of the mediastinum away from the postpneumonectomy space (PPS), failure of the mediastinum to shift normally in the immediate postoperative period, development of a new air-liquid level, or a sudden change in a preexisting air-liquid level (image 4). However, changes in fluid levels in the postpneumonectomy space have been described in asymptomatic patients, a condition called “benign emptying of the postpneumonectomy space,” and may not require any intervention [28]. The diagnosis of postpneumonectomy empyema is confirmed by sampling the fluid in the PPS. (See "Pleural fluid analysis in adults with a pleural effusion".)

Treatment includes drainage of the PPS and systemic antibiotics, plus repair of any coexisting bronchopleural or esophagopleural fistula once the PPS is sterilized [29]. Patients with large (>3 mm) bronchopleural fistulas should be treated with aggressive surgical debridement, irrigation of the pleural cavity, and closure of the pneumonectomy stump with an omental patch (Clagett procedure) [30-32]. A less invasive approach using video-assisted thoracoscopy may be useful in the absence of a bronchopleural fistula, and in those with a small (<3 mm) fistula [33,34]. (See "Management and prognosis of parapneumonic pleural effusion and empyema in adults".)

Bronchopleural fistula — Bronchopleural fistula occurs with a frequency ranging from 1.5 to 4.5 percent and is associated with a mortality ranging from 29 to 79 percent. Bronchopleural fistulas occurring within one week of surgery are not necessarily associated with an empyema, whereas those occurring more than two weeks after surgery are associated with an empyema. Risk factors for formation of a bronchopleural fistula include right-sided procedures, a large diameter (>25 mm) bronchial stump, residual tumor, concurrent radiation therapy or chemotherapy, age greater than 60 years, poor wound healing, and prolonged postoperative mechanical ventilation [35-37]. (See "Bronchopleural fistula in adults".)

Signs and symptoms include fever, productive cough, hemoptysis, subcutaneous emphysema, and persistent air leak from a chest tube. Later development of a bronchopleural fistula and empyema may just be associated with nonspecific symptoms, as described earlier for a late PPS empyema. Chest radiographs frequently demonstrate a new air-liquid level in the PPS, multiple air-liquid levels in the PPS, or a change in a preexisting air-liquid level.

Treatment of late bronchopleural fistulas as well as early bronchopleural fistulas associated with empyema includes drainage of the pleural space, systemic antibiotics, and then repair of the air leak once the PPS has been sterilized [31]. Bronchopleural fistulas that occur within one week of surgery and are not associated with an empyema can be surgically closed. The management of bronchopleural fistulas in patients with respiratory failure requiring positive pressure mechanical ventilation is discussed separately. (See "Management of persistent air leaks in patients on mechanical ventilation".)

Esophagopleural fistula — Esophagopleural fistula formation occurs with a frequency of 0.5 percent and is more common after right-sided procedures. Most develop at least a year after pneumonectomy and are due to recurrent tumor eroding into the esophagus. Because esophagopleural fistulas are always associated with an empyema, symptoms are identical to those accompanying a late postpneumonectomy empyema. Diagnosis can be confirmed by performing a barium swallow.

Treatment is supportive if the fistula is due to recurrent tumor. Otherwise, treatment consists of drainage of the PPS, systemic antibiotics, and surgical repair of the fistula once the PPS is made sterile. Mortality approaches 65 percent.

Chylothorax — Chylothorax, which occurs with a frequency less than 1 percent, develops within 15 days of surgery, usually in those patients who undergo concurrent lymph node resection. The diagnosis should be considered when there is rapid filling of the PPS in the immediate postoperative period. (See "Etiology, clinical presentation, and diagnosis of chylothorax".)

Asymptomatic patients with slow accumulation of chyle can be treated conservatively with bowel rest, and the chylothorax eventually resolves spontaneously. Patients with signs and symptoms of elevated central venous pressure, tachycardia, dyspnea, and hypotension as well as radiographic evidence of rapid filling of the PPS require drainage and surgical repair.

Acute hemothorax — Rapid filling of the PPS with blood can occur within 24 hours of surgery (image 5). This complication is more common after pleuropneumonectomy or pneumonectomy for suppurative lung disease. The clinical presentation may be with hypotension and shock due to the loss of intravascular blood volume. The mainstay of treatment is surgical reexploration and control of bleeding sources.

Contralateral pneumothorax — Contralateral pneumothorax is a rare complication that is usually seen in the immediate postoperative period. Proposed mechanisms have included intraoperative damage to the contralateral mediastinal pleura, rupture of preexisting blebs or bullae, or single pleural space (“buffalo chest”; buffalo have a single thoracic cavity). Signs and symptoms include sudden onset of dyspnea and hypoxemia, and the diagnosis is confirmed by chest radiography. Management includes evacuation of the air in the pleural space in order to achieve reexpansion of the underlying lung. Mortality is approximately 50 percent. (See "Clinical presentation and diagnosis of pneumothorax", section on 'Pneumothorax appearance and types' and "Treatment of secondary spontaneous pneumothorax in adults".)

CARDIOVASCULAR COMPLICATIONS — In addition to cardiovascular complications that can occur in association with any type of surgery, such as arrhythmias, myocardial infarction, and pulmonary embolism, other complications such as intracardiac shunting and cardiac herniation are specifically related to the pneumonectomy procedure.

Arrhythmia — Cardiac arrhythmias occur in approximately 20 percent of patients following pneumonectomy, with most (80 percent) presenting within 72 hours of surgery. Atrial fibrillation is by far the most common arrhythmia following lung resection. Reported risk factors for development of a postoperative arrhythmia include age greater than 65 years, right pneumonectomy, male sex, clamshell incision, intrapericardial pneumonectomy, preexisting coronary artery disease, and hypertension [38,39]. Extrapleural pneumonectomy appears to further increase the risk of atrial fibrillation, which occurred in 145 of 328 patients (44 percent) in one large series [40]. (See "Initial management of malignant pleural mesothelioma".)

Atrial fibrillation after lung resection is associated with an increased incidence of other postoperative complications, longer hospitalization, and greater costs [38]. Mortality rates associated with post-pneumonectomy arrhythmias may be as high as 20 percent [39]. Risk factors for developing atrial fibrillation after a pneumonectomy may include increasing age, male sex, and resection stage II or higher lung cancer [41].

Treatment varies according to the nature of the arrhythmia, the presence of active bronchospasm or wheezing, and degree of cardiopulmonary compromise associated with the arrhythmia. Guidelines for treatment of the most common of these arrhythmias, atrial fibrillation, in the setting of pneumonectomy are presented in the table (table 2). Urgent electrical cardioversion of supraventricular tachyarrhythmias is indicated if hemodynamic collapse, angina, or heart failure is present. Acute myocardial ischemia and any electrolyte, acid-base, or other metabolic abnormalities, particularly hypokalemia and hypomagnesemia, should be treated or corrected. The treatment of new onset atrial fibrillation and the treatment of atrial fibrillation in patients with COPD are discussed separately. (See "Arrhythmias in COPD", section on 'Atrial fibrillation and supraventricular tachyarrhythmias' and "Atrial fibrillation: Overview and management of new-onset atrial fibrillation".)

Given the high rate of postoperative atrial fibrillation after pneumonectomy (12 to 20 percent), the role of perioperative prophylaxis with agents, such as beta-1 selective agents, calcium channel blockers, amiodarone, and sotalol, is under investigation [42-47]. The prevention of postoperative atrial fibrillation is discussed in greater detail separately. (See "Overview of pulmonary resection".)

Patients taking beta-1 blockers prior to thoracic surgery should continue them perioperatively, as beta-blocker withdrawal can increase the risk of atrial fibrillation [47].

Myocardial infarction — Myocardial infarction following pneumonectomy occurs with a frequency of 1.5 to 5 percent. Management follows the usual considerations for management of myocardial infarction in other settings. Mortality from this complication following pneumonectomy is in excess of 50 percent. (See "Overview of the acute management of ST-elevation myocardial infarction".)

Pulmonary embolism — The incidence of thromboembolic disease complicating pneumonectomy may be as high as 9 percent [48,49]. Pulmonary embolism following pneumonectomy can originate from several sources. In addition to the deep venous system of the lower extremities, thromboembolism can rarely originate from the pulmonary artery stump (image 6), a complication that is more frequent after right pneumonectomy. Patients undergoing pneumonectomy should receive deep venous thrombosis prophylaxis in accordance with established guidelines. (See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients".)

In addition, tumor emboli may occur in patients with tumor invading the left atrium or the main pulmonary artery. Air embolism after pneumonectomy is rare and can usually be avoided by using a split-bronchus endotracheal tube and only ventilating the non-operated lung. (See "Pulmonary tumor embolism and lymphangitic carcinomatosis in adults: Diagnostic evaluation and management" and "Air embolism".)

Management of thromboemboli typically includes anticoagulation, but emergency embolectomy may be required. Successful treatment of pulmonary embolism after lung resection with recombinant tissue plasminogen activator (tPA) has been reported [50]. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults".)

Intracardiac shunting — An unusual complication following pneumonectomy is a right-to-left shunt that develops through a patent foramen ovale or an atrial septal defect. Although such right-to-left shunting can be precipitated by elevation in right heart pressures, it can also occur in the absence of elevated right atrial pressure due to a change in cardiac geometry, directing flow from the inferior vena cava across the interatrial communication. (See "Clinical manifestations and diagnosis of atrial septal defects in adults".)

Symptoms of right-to-left shunting include dyspnea and platypnea, typically developing between two days and one year following surgery. Diagnosis of a right-to-left shunt can be made on a nuclear medicine scan or by performing a shunt study on 100 percent oxygen. The cardiac location of the shunt can be confirmed by contrast echocardiography. Correction of the atrial septal defect or closure of the foramen ovale is curative. (See "Management of atrial septal defects in adults" and "Clinical manifestations and diagnosis of atrial septal defects in adults".)

Cardiac herniation — Cardiac herniation, a rare complication following intrapericardial right or left pneumonectomy, involves herniation of the heart through the defect in the pericardium and into the empty pleural (postpneumonectomy) space [51-53]. This can result in torsion and twisting of the heart (image 7).

Cardiac herniation is usually seen within three days of surgery, presenting as sudden onset of hypotension and shock, cyanosis, chest pain, and superior vena cava syndrome. The acute event is usually preceded immediately by coughing, moving the patient, vomiting, or extubation.

Treatment involves emergent surgery to reposition the heart and close the pericardial defect to prevent recurrence. Cardiac herniation may be prevented by primary closure of the pericardial defect at the time of pneumonectomy, or by suturing the edges of the pericardial defect to the myocardium [54].

OTHER COMPLICATIONS — A variety of miscellaneous complications have also been described following pneumonectomy.

Esophageal motility disorders — Esophageal studies following pneumonectomy have demonstrated abnormalities in esophageal sphincter pressure, esophageal body pressure, and peristalsis. Because these changes have not been extensively studied, their clinical implications are unknown. However, symptoms of dysphagia appear to be infrequent.

Gastric volvulus — Gastric volvulus is a rare complication that has been seen more than one year following surgery. It probably occurs as a result of anatomic changes after surgery [55].

Acute kidney injury — The incidence of acute kidney injury (AKI) after pneumonectomy may be as high as 14 percent. Risk factors include underlying hypertension, diabetes, peripheral vascular disease, decreased preoperative renal function, preoperative use of angiotensin II receptor blockers, and intraoperative use of hydroxyethyl starch [56].

Lactation — Lactation can rarely occur after thoracotomy as a result of irritation of the anterior branches of the thoracic nerves. Treatment options include oral estrogen and progesterone, or nerve block.

Pneumopericardium — Pneumopericardium is a rare complication that occurs as a result of direct communication between a bronchopleural fistula, the bed of the pulmonary artery, and the pericardium. In some cases, it may be complicated by development of cardiac tamponade. Diagnosis can be suggested by a pericardial "crunch" on physical examination or by a chest radiograph; treatment requires emergent surgery.

Postpneumonectomy paralysis — Postpneumonectomy paralysis is a rare complication due to intraoperative injury to the left lower intercostal arteries. These vessels feed the arteria magna, which in turn provides much of the blood supply to the thoracolumbar region of the spinal cord. This complication can also result from development of an epidural hematoma.

Postpneumonectomy scoliosis — Ninety percent of patients develop mild thoracic scoliosis after pneumonectomy due to shrinkage of the thoracic cage after surgery. Associated symptoms have not been reported in the postoperative period.

PROGNOSIS

Mortality — Contemporary 30-day mortality rates range from 2 to 11 percent, based upon both retrospective and prospective studies that have been published since 1990, each containing over 100 patients [57-61]. Thirty-day mortality for pneumonectomy for benign lung disease may be as high as 26 percent [62,63]. While some cohort studies report ten-year survival rates for patients who underwent pneumonectomy for non-small cell lung cancer that range from 67 to 85 percent [64], other studies suggest the overall five-year survival may be as low as 21 percent [60]. Several risk factors are associated with an increased 30-day mortality:

●Right-sided pneumonectomy is associated with a higher mortality rate than left-sided pneumonectomy (10 to 12 versus 1 to 3.5 percent, respectively) [65,66]. While the reasons are not certain, likely factors include several life-threatening complications that are encountered more frequently after right pneumonectomy; these include postpneumonectomy space empyema, bronchopleural fistula, and postpneumonectomy pulmonary edema.

●The specific type of surgical resection is an independent risk factor for mortality. As an example, pleuropneumonectomy and pneumonectomy with chest wall resection are associated with a threefold increase in mortality compared to a simple or intrapericardial pneumonectomy [66]. Completion pneumonectomy (ie, a reoperation to remove the remaining portion of a previously, partially resected lung) for both benign and malignant disease has been associated with an operative mortality of 10 percent [67].

●Pneumonectomy performed emergently for trauma or massive hemoptysis is associated with a mortality rate exceeding 35 percent, likely reflecting the severity of the underlying process [2,68]. (See "Evaluation and management of life-threatening hemoptysis".)

●Several comorbid medical illnesses have been identified as risk factors for increased mortality. These include underlying lung disease, coronary artery disease, heart failure, atrial fibrillation, hypertension, hemiplegia, active cigarette smoking, poor nutritional status, and weight loss greater than 10 percent within the six months preceding surgery [58,59,69,70].

●While some studies have demonstrated that increased age (eg, >60 to 75 years) is a risk factor for increased mortality with pneumonectomy, others have not [71-73].

●The level of experience of the surgeon performing the operation may affect the mortality rate [73,74]. A lower mortality rate for lung cancer resection has been demonstrated when the surgery is performed by a thoracic surgeon rather than a general surgeon [74].

●It remains unclear whether preoperative chemotherapy and/or radiation therapy increase operative mortality and morbidity, as studies have found conflicting results [75,76].

●Perioperative blood transfusions do not appear to increase mortality [77].

Quality of life — Quality of life in patients who have undergone pneumonectomy has been reported to be significantly lower than the general population [78]. Patients over age 70 and those with low preoperative quality of life appear more likely to have an unacceptable quality of life six months following pneumonectomy than other patients [79].

SUMMARY AND RECOMMENDATIONS

●Consequences of pneumonectomy – Pneumonectomy is associated with a variety of reasonably predictable anatomic changes, significant decrements in pulmonary function, and a number of potential complications that involve the respiratory system, the cardiovascular system, and the pleural space [3] (table 1). (See 'Introduction' above.)

•Early postoperative changes – Chest radiographic findings immediately after surgery demonstrate the trachea to be midline and the postpneumonectomy space (PPS) to be filled with air (image 1A-B). Within 24 hours, air absorption leads to small shifts in the hemidiaphragm and mediastinum, as well as fluid accumulation. As a general rule, initially fluid accumulates at a rate of one to two intercostal spaces per day. After two weeks, 80 to 90 percent of the PPS is filled with fluid. The location of vital organs (including the heart and great vessels, liver, and spleen) changes significantly following pneumonectomy as a consequence of mediastinal shift and elevation of the hemidiaphragm (image 2A-C). (See 'Changes in postpneumonectomy space' above.)

•Pulmonary function – Postpneumonectomy lung volumes and diffusing capacity for carbon dioxide (DLCO) fall, but typically less than expected for removal of approximately 50 percent of the original lung tissue. (See 'Postoperative pulmonary function' above.)

•Hemodynamics – As long as the remaining lung is relatively normal, there is no significant change in resting values of systolic pulmonary artery pressure, pulmonary vascular resistance index, or central venous pressure after lung resection. (See 'Postoperative cardiovascular function' above.)

•Quality-of-life – Unlike patients who have had lobectomies and wedge resections, patients who have had pneumonectomies have a lower quality of life with regard to of overall physical function, pain, and dyspnea. (See 'Quality of life' above.)

•Mortality – Thirty-day mortality rates after pneumonectomy range from 2.4 to 11.6 percent, and ten-year survival rates for patients who underwent pneumonectomy for non-small cell lung cancer range from 67 to 85 percent, depending on size and stage of the tumor. (See 'Mortality' above.)

●Complications of pneumonectomy

•Postpneumonectomy pulmonary edema – Postpneumonectomy pulmonary edema is a form of noncardiogenic pulmonary edema that occurs with an overall frequency of 2 to 5 percent. It is three times more common following right than left pneumonectomy. (See 'Pulmonary edema' above.)

•Postpneumonectomy syndrome – This syndrome arises from extrinsic compression of the distal trachea and mainstem bronchus due to shifting of the mediastinum and hyperinflation of the remaining lung (image 3). It occurs more than six months following surgery and has even been reported 35 years after surgery. It is more common in patients who undergo surgery in childhood and is almost exclusively seen after right pneumonectomy. (See 'Postpneumonectomy syndrome' above.)

•Pleural complications – Postpneumonectomy complications affecting the pleural space include infection, fistula formation, bleeding, chylothorax, and contralateral pneumothorax. (See 'Pleural space complications' above.)

•Cardiac complications – Intracardiac shunting can develop postpneumonectomy with a right-to-left shunt through a patent foramen ovale or an atrial septal defect, due to elevated right atrial pressure or a change in cardiac geometry. Cardiac herniation can result in torsion and twisting of the heart (image 7). (See 'Cardiovascular complications' above.)

•Less common complications – Other potential complications include esophageal dysmotility, gastric volvulus, lactation, pneumopericardium, postpneumonectomy paralysis, and postpneumonectomy scoliosis. (See 'Other complications' above.)