Cervical and retrosternal approach to the left thoracic cavity using a flexible endoscope

Mediastinoscopy remains the gold standard for surgical exploration of the mediastinum. The use of this approach to access the left thoracic cavity could be complicated by vascular or neurological lesion. The aim of this experimental work was to describe a new approach to the left thoracic cavity through a cervical incision and retrosternal space using a flexible endoscope as a unique instrument.

We conducted an experimental work on 12 refrigerated and non-embalmed cadavers. Through a cervical incision, we dissected the retrosternal space to the level of Louis angle and then opened the left mediastinal pleura. We introduced the flexible endoscope through this pleural window into the left thoracic cavity. We defined three distances between the borders of the endoscope entry point, the phrenic nerve and the mammary artery: Distance 1: between the medial edge of the endoscope entrance point and the medial edge of the left mammary artery, Distance 2: between the top of the endoscope entrance point and the penetration of phrenic nerve in the left thoracic cavity and Distance 3: between the lateral edge of the entrance point of the endoscope and the medial edge of the phrenic nerve. To measure these distances, we performed a left postero-lateral thoracotomy.

Procedure was successfully executed in 10 of the 12 studied subjects. The mean distances 1, 2 and 3 were 17.1 (range 2-40), 39.5 (17-80) and 19.1 mm (10-40), respectively. The minimal Distance 1 was in two subjects 0.2 and 0.5 mm.

This approach avoids the para-aortic and supra-aortic zone; this access could be less dangerous than already described access techniques. Despite the limits of our work on cadavers, and the two failures in the application of the access, the mean distances we calculated show the potential safety of our approach concerning the phrenic nerve and the mammary artery. An experimental protocol on living animals is currently underway with the aim of confirming the safety of our approach.