Is the preservation of the phrenic nerve important after pneumonectomy?

Abstract

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: is the preservation of the phrenic nerve important after pneumonectomy? Altogether more than 49 papers were found using the reported search, of which four represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that care should be taken to preserve the integrity of the phrenic nerve wherever possible. The abnormal diaphragmatic motion which occurs as a consequence of phrenic nerve damage significantly reduces expiratory lung volumes, gas exchange and exercise capacity in already compromised patients. Phrenic nerve injury can also lead to a prolonged need for mechanical ventilation; this alone carries a risk of complication, such as infection. Plication of the paralyzed hemi-diaphragm has proved effective in reducing respiratory insufficiency after pneumonectomy. The aim of this is to fix and flatten the diaphragm, thus mimicking the role of a functioning phrenic nerve. Furthermore, the function of a preserved phrenic nerve remains normal for up to 11 years post pneumonectomy. Therefore, deterioration in function may highlight a recurrence in disease or a change in the post pneumonectomy space.