Haemodynamic complications after pneumonectomy: atrial inflow obstruction and reopening of the foramen ovale.

BACKGROUND: Haemodynamic impairments after pneumonectomy are rare complications and present in different forms. Due to a low awareness of these potential complications their diagnosis is difficult and often established late. The most important forms are: firstly reopening of a previously closed foramen ovale (PFO) caused by a combination of changed anatomic position of the left atrium and elevated pulmonary artery pressure leading to a significant right-left shunt; secondly diaphragmatic relaxation can lead to a dislocation of the liver into the right hemithorax, compressing the right atrium with subsequent inflow obstruction.
METHODS: We retrospectively analysed our patient cohort from 1997 to 2006 for occurrence of haemodynamic complications requiring surgical intervention after pneumonectomy.
RESULTS: Five hundred and forty-six pneumonectomies were performed in our centre during the observation period. Five patients (1 female, 4 male, age 59+/-9 years) with haemodynamic complications were identified. Two of those patients were referred with haemodynamic complications after pneumonectomy was performed in a peripheral centre. All patients had undergone right pneumonectomy for NSCLC (n=4) or atypical carcinoid (n=1). Two patients were readmitted 3 months and 2 years postoperatively due to increasing platypnoea and orthodeoxia. After closure of the reopened foramen ovale, which was found as the underlying pathological mechanism, respiratory symptoms were resolved. One patient required reintubation 2h postoperatively; after surgical closure of a PFO the respiratory situation significantly improved. One patient was readmitted due to right atrial inflow obstruction 17 months after right pneumonectomy. Underlying cause was a severe diaphragmatic relaxation with compression of the atrium by the liver. After diaphragmatic plication all symptoms resolved. However 1 year thereafter reoperation for recurrence of diaphragmatic elevation was required. One patient was readmitted 3 months after pneumonectomy and partial atrial resection for cyanosis and dyspnoea. Diagnostics revealed a PFO and a massive raise of the right diaphragm with compression of the right atrium. After surgical correction of the contorted foramen ovale and diaphragmatic plication, symptoms vanished.
CONCLUSION: Haemodynamic alterations due to a reopened foramen ovale or right atrial inflow obstruction are rare, however they are severe complications after pneumonectomy. They occur at variable points in time after pneumonectomy. Diagnostic efforts are often made at a late stage due to a low awareness of the problem. Closure of the PFO either surgical or interventional and/or plication of the elevated diaphragm are mandatory. In our experience these complications occur only after right pneumonectomy.