Left costomediastinal recess of the pleura, the potential pleural space anterior to the heart.

OBJECTIVE

To investigate clinical implications of the left costomediastinal recess of the pleura.

METHODS

The left anterior pleural anatomy was studied in 12 cadavers. Chest computed tomography (CT) scans of 68 healthy/near-healthy patients were reviewed for the recess. Twenty pleural lesions in the recess were analyzed on CT. Eight cases of left paracardiac pericardiocentesis were analyzed for pleural complications.

RESULTS

Two fresh cadavers showed the recess to be wider downward, measuring 75 and 55 mm in width at the sixth intercostal space. None of the 68 healthy/near- healthy CT scans displayed the recess. Twenty recess lesions were connected to similar pleural lesions surrounding the left lung (n = 19) or showed an isolated lesion therein only partly facing the left lung (n = 1). Ipsilateral pleural effusion complicated 3 of 7, successful left paracardiac pericardiocentesis.

CONCLUSION

Regardless of their contiguity with the lung, the differential diagnosis of precordial lesions should include pleural diseases in the recess. Left anterior pericardiocentesis unavoidably violates the intervening recess, sometimes causing pleural effusion.