Mediastinoscopy

Historical techniques

Harken technique - not favoured due to technical difficulty and complication rate
Radner technique - biopsy of paratracheal lymph nodes through an incision in the suprasternal notch

Absolute
- Contraindication to GA
- Extreme kyphosis
- Cutaneous tracheostomy after laryngectomy

Positioning
- ETT positioned left corner of mouth
- Neck in hyperextension with shoulder roll
- Drape to allow median sternotomy
- Surgeon stands/sits behind patient's head
2-3cm transverse incision, one fingerbreadth above the manubrium
Separate pre-tracheal muscles vertically in the midline, to expose the anterior surface of the trachea, while the isthmus of the thyroid is retracted superiorly. Expose trachea and pre-tracheal fascia incised, to allow that pre-tracheal plane to continue down into the mediastinum
Blunt dissection in pre-tracheal plane using index finger (stay right on the trachea)
- Palpate for pre-tracheal nodes (easier to feel them than see them)
- Aortic arch to patient's left and innominate artery passing across the top of the operative field
- Develop plane as far down as carina
Insert mediastinoscope, staying right on trachea or main-stem bronchi at all times to avoid vascular injury
Identify right and left mainstem bronchi, and then systematically dissect the subcarinal space, the ipsilateral paratracheal space, and the contralateral paratracheal space
Biopsy nodal stations as needed
- Generally save subcarinal for last as it bleeds the most
Closure
- Approximate strap muscles
- Drain usually not required
- Obliterate dead space if needed
- Close skin

Bleeding
- Most frequently small bronchial arteries running across the subcarinal region
- More serious bleeding from azygos or RUL branch of PA
- Injury to aorta or innominate artery may require sternotomy
Injury to left RLN
Injury to oesophagus or trachea