Introduction

A clamshell thoracotomy provides almost complete exposure to both thoracic cavities. In general, the indications for performing a clamshell thoracotomy are when you need access to both sides of the chest, or just when you need better access than a unilateral thoracotomy can give you. For example:

• To improve exposure and access to the heart (especially right sided structures) following a left anterolateral thoracotomy performed for profound hypotension or traumatic arrest
• To provide access to the right chest in transmediastinal injuries or multiple penetrating injury to both the left and right chest.
• To allow cardiac massage following a right-sided thoracotomy.

The only part of the thoracic cavity that is not easily reached through a clamshell incision is the very superior mediastinal vessels. If there is an injury here, the sternum can be split to provide wide exposure to this area.

Technique

The clamshell thoracotomy usually starts as a standard left anterolateral thoracotomy - often an emergency department thoracotomy for traumatic arrest as in this case. The left thoracotomy is placed in the 5th intercostal space (just below the nipple).

Access following a left anterolateral thoracotomy is fairly limited. The clamshell is made by performing a right sided thoracotomy in the same interspace:

Once the full thoracotomy has been completed on both sides, the sternum must be split. This can be accomplished with a Gigli saw or, more usually, a heavy pair of trauma scissors or other shears:

(Note the correct technique for bimanual cardiac massage and a cross clamp on the descending aorta in the above picture)

Dividing the sternum will also divide the inferior mammary arteries on both sides. Usually these do not bleed at this stage due to profound hypotension, but will start to bleed once blood volume and flow is restored. These will need to be ligated at some point in the future.

The rib retractor is placed between the cut ends of the sternum and opened. The fibrofatty tissue between the sternum and the anterior pericardium should be divided with scissors.

This allows the sternum to be fully elevated and provides excellent exposure to the heart and both thoracic cavities.

The patient in this series had a gunshot injury to the right middle lobe and main pulmonary artery.

Closing the incision

Don't forget to check the inferior mammary arteries and ligate both ends if you haven't done so already.

Large bore chest drains should be placed in both thoracic cavities, the mediastinum and pericardium (if opened).

The thoracotomy incision is closed in layers as with the standard anterolateral thoracotomy. The sternum can be re-approximated with sternal wires or with 5 Ethibond sutures.

Occasionally attempts to close the chest will result in cardiac arrest as the heart has become so oedematous it does not tolerate the compression. In this case, a temporary closure is performed with a plastic bag (3L cystostomy irrigation fluid bag or similar) and the chest closed at a subsequent procedure when the swelling has subsided.

References

trauma.org (10:4) April 2005