Mediastinoscopy

Anesthesia Implications

Position: Supine, Bed turned 90 degrees
Time: 30-60 min (short)
Blood Loss: Low (10-50 ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: Yes

Anesthetic Approaches

  • GETT
The Anesthesia

Myasthenia Gravis – If procedure is thymus related the patient may have myasthenia gravis. Remember to avoid succinylcholine in these patients.

Innominate Artery Compression – If innominate artery compression occurs, alert the surgeon. Compression can cause cerebral ischemia or stroke. To monitor this, an arterial line should be placed in the right radial or axillary artery. Compression can seen by the dampening of the arterial waveform (which can also be observed by the dampening of the pulse-ox waveform if placed on the right upper extremity).

High blood loss risk – Because of the proximity of the surgery to major vessels, there is a high blood loss risk (though not common).
Type and screen is necessary pre-operatively. Get a large bore IV.

BP cuff – keep the cuff on the opposite arm (left arm) of the arterial line.

Positioning – After intubation, the patient is usually turned 90 degrees away from anesthesia machine (surgeon will be standing over the patient’s head).

ETT and Circuit – Make sure to place ETT and circuit tubing away from patient’s neck/chest area. You’ll want to reinforce ETT as patients head will be covered with drapes and the surgeon will be in your space.

Bradycardia – Watch for bradycardia and/or arrhythmias when aortic compression occurs. HR will usually return to normal when compression is released, but keep Robinul and/or atropine on hand.

Arterial line (general considerations): Preoperatively check pulses to gauge the best side to attempt the A-line. Perform an Allen test to ensure adequate blood flow. Have the A-line equipment set up and ready in the room.

The Pathophysiology

The mediastinum is an area between the two pleural cavities, extending to the diaphragm. Most Mediastinoscopies are diagnostic in nature, due to the large about of lymph nodes in this area. Staging lung cancer requires mediastinum lymph node biopsies, so many of these patients are newly diagnosed with lung cancer.

Thymus cancer resection or tumors in the mediastinum also require a mediastinoscopy.

The Surgery

Types of Mediastinoscopy:

Anterior – Transthoracic approach, more risk for bleeding or pleural cavity involvement. Typically done in a hospital OR setting.

Cervical – Small incision is created in the suprasternal notch, then a tunnel is made to the subcarinal area, avoiding the thymus and anterior mediastinum. Typically an outpatient procedure.