Biopsy of Mediastinal Lesions

Abstract

Image-guided percutaneous needle biopsy allows access to lesions in virtually all mediastinal locations. A direct mediastinal approach that enables extrapleural needle placement is the preferred method for avoiding the risk of pneumothoraces. Using computed tomography (CT) or ultrasound (US) guidance, the parasternal, paravertebral, transsternal, and suprasternal approaches all allow extrapleural access to many mediastinal lesions. The parasternal approach is used for biopsy of an anterior or middle mediastinal lesion when the lesion or intervening mediastinal fat extends to the anterior chest wall, lateral to the sternum; injury to the internal mammary vessels is a potential complication. The posterior paravertebral approach permits extrapleural needle placement for biopsy of subcarinal and other posterior mediastinal lesions; saline injection is often used with this technique to widen the mediastinum. The transsternal approach, which involves needle placement through the sternum, is used for biopsy of anterior or middle mediastinal lesions that are not safely accessible by the parasternal approach. The suprasternal approach can be used to biopsy superior mediastinal lesions. An alternative to these direct mediastinal approaches for biopsy of mediastinal lesions involves advancing the needle through the pleural space created by an existing pleural effusion or iatrogenic pneumothorax. The transpulmonary approach involves needle traversal of the lung and visceral pleura and is associated with a substantial risk of pneumothorax. This chapter reviews the various approaches used for image-guided percutaneous mediastinal needle biopsy and discusses the anatomic and technical aspects, advantages, limitations, and potential complications of each technique as well as briefly describing several alternative methods for accessing mediastinal lesions.