Relation of interlobar collaterals to radiological heterogeneity in severe emphysema
- 1Lung Transplant Service, Department of Allergy, Immunology and Respiratory Medicine, The Alfred Hospital, Melbourne, Victoria, Australia
- 2Department of Cardiothoracic Surgery, The Alfred Hospital, Melbourne, Victoria, Australia
- 3Department of Radiology, The Alfred Hospital, Melbourne, Victoria, Australia
- 4Monash University Department of Epidemiology and Preventive Medicine, The Alfred Hospital, Melbourne, Victoria, Australia
- Correspondence to:
Dr G I Snell
Lung Transplant Service, The Alfred Hospital, Commercial Road, Melbourne 3004, Victoria, Australia;
- Received 8 August 2005
- Accepted 25 January 2006
- Published Online First 7 February 2006
Background: A study was undertaken to assess the prevalence of interlobar collateral ventilation in patients with severe emphysema to identify factors that may help to predict patients with significant collateral ventilation.
Methods: Between April 2002 and August 2003, ex vivo assessment of the lungs 17 consecutive patients with smoking related severe emphysema was performed. To assess collateral flow, all lobes of explanted specimens were selectively intubated using a wedged cuffed microlaryngeal intubation tube and then manually ventilated using a bagging circuit. Interlobar collateral ventilation was defined as the ability to easily inflate a non-intubated lobe at physiological pressures. Pre-transplant demographic characteristics, physiological data, radiological results, and explant histology were assessed for retrospective relationships with the degree of interlobar collateral ventilation in the explanted lung.
Results: A total of 23 lungs were evaluated, 15 of which (66%) had significant collateral interlobar airflow. There were no significant differences in any demographic, physiological, or pathological variables between patients with collateral ventilation and those with no collateral ventilation. However, there was a significant relationship between the presence of interlobar collateral ventilation and radiological scores (p<0.05).
Conclusions: Interlobar collateral ventilation occurs to a much greater extent in patients with radiologically homogeneous emphysema than in those with heterogeneous emphysema. Heterogeneity of emphysema may predict patients with a significantly reduced risk of interlobar collateral ventilation.
- FEV1, forced expiratory volume in 1 second
- FVC, forced vital capacity
- LVRS, lung volume reduction surgery
- Tlco, carbon monoxide transfer factor
- ULPR, upper/lower perfusion ratio
Published Online First 7 February 2006
Competing interests: none declared.