Post-pneumonectomy Complications


The mortality rate following pneumonectomy is approximately 6%, which is three times higher than after lobectomy. Complications are more common following right pneumonectomy than left. The major causes of death are pneumonia (mortality 25%), pulmonary edema, pulmonary embolism, myuocardial infarction, empyema, and bronchopleural fistula. 


In the normal post-pneumonectomy chest the potential pleural space is replaced by liquid from bleeding, weeping from lymphatics, and passive transudation. Gas is usually resorbed with 7 to 14 days, but the process can require up to 6 months and in some patients a small amount of gas persists indefinitely. Rapid opacification of the potential pleural space may reflect hemorrhage. Chylothorax secondary to thoracic duct injury can also occur. The mediastinum and heart gradually shift toward the side of the pneumonectomy and the remaining lung will expand across the mid-line. A contralateral mediastinal shift of up to 3.5 cm with expiration is acceptable. On long term follow-up, CT demonstrates that approximately two-thirds of patients maintain a liquid filled space with thick fibrous margins, while the remaining patients have fibrous tissue or normal mediastinal structures.  

Cardiac herniation/torsion

Initial film post right pneumonectomy. Chest probably should have been reopened before this x-ray was taken.

Inject air into drain makes more obvious

Putting a Swan-Ganz in helps delineate the anatomy


Bronchopleural Fistula:


Clinical:


The incidence of bronchial stump leak is 5% with a mortality rate of 16-23%. It is more common following right pneumonectomy. Leakage during the first week is likely due to poor closure requiring re-operation. Leakage in the second or third week is usually due to poor healing. Radiologic signs of PBF include failure of the potential pleural space to fill with liquid, inspiratory shifting of the mediastinum to the contralateral (non-operated) side, and an abrupt decrease in the gas-liquid level greater than 2 cm in height. BPF can lead to empyema formation (about 5% of empyemas are associated with bronchopleural fistulas. 

o       Causes:

         Necrosis of bronchial stump

         Dehiscence of suture line

o       More common on the right

o       Increased risk in association with

         Residual carcinoma

         Preoperative radiation

         Diabetes

o       Clinical

         Sudden onset of dyspnea

         Expectoration of bloody fluid

o       Imaging findings

         Return to midline of a previously shifted mediastinum

         A drop in the fluid level by more than 2 cm is abnormal

 

 

Top image demonstrates an air-fluid level normal for the 5th post-operative day;
the lower image taken two weeks later shows a drop in the
height of the fluid level highly suggestive of a bronchopleural fistula

 

         Thin-section CT may demonstrate the BP fistula

 


Pulmonary Edema:


Clinical:


Post-pneumonectomy pulmonary edema can result from volume overload or abrupt hyperperfusion- typically within 24 to 48 hours after surgery. It occurs in 1-5% of post-pneumonectomy patients . The condition occurs more commonly after right pneumonectomy (the remaining left lung has a smaller volume) and should be treated aggressively with diuretics. 


Post-pneumonectomy Syndrome:


Clinical:


Post-pneumonectomy syndrome is a rare, delayed complication of right pneumonectomy (rarely left pneumonectomy in patients with right aortic arches). The syndrome occurs secondary to severe mediastinal shift which results in rotation of the heart and great vessels, and herniation of the remaining lung into the contralateral hemithorax. The airway can be compressed by the thoracic spine, descending aorta, ligamentum arteriosum, or pulmonary artery. Patients present with dyspnea and recurrent infections in the remaining lung. Surgical repositioning of the mediastinal structures can be curative. 


Stump Clot:


Clinical:


Stump clot is not uncommon. Clot is more frequent on the right due to a longer stump. The main risk is for propagation or migration into the remaining pulmonary circulation which could be fatal , however, this risk of this is uncertain.

Recurrent neoplasm

Hemorrhage

Chylothorax

Empyema