Preoperative pulmonary nodule localization

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Preoperative pulmonary nodule localization is a CT-guided procedure where a marker is applied to a usually small lung lesion to assist its surgical identification and resection. The widespread use of video-assisted thoracic surgery (VATS) and the advance in robotically assisted surgical interventions have increased the need for preoperative markers, as small lesions will not always be identified by surgeons visual inspection and palpation.

Indications

Although preoperative marking may be applied to potentially any focal pulmonary lesion, it is most commonly indicated in small solid nodules or groundglass opacities:

  • smaller than 10-15 mm
  • located more than 5-10 mm in depth from the pleural surface

Contra-indications 

Contra-indications would be similar to a pulmonary biopsy, including:

  • uncooperative patient
  • lack of safe access
  • uncorrectable bleeding diathesis (abnormal coagulation indices)

Procedure 

Usually, cases have been already discussed in a multidisciplinary meeting and radiologists and thoracic surgeons from the same institution are familiar with a specific type of marker and procedure technique.

Preprocedural evaluation

Review of previous scans is mandatory for approach planning.

Marker 
  • metallic marker  
    • gold fiducial markers
      • disadvantages: potential embolization into a pulmonary vein (rare)
    • hook-wire
      • disadvantages: skin entry do be determined in accordance with the surgeon, surgery must be performed immediately after, and potential wire dislodgement (up to 9% of cases)
    • micro coils
  • injected material through a fine needle
    • methylene blue
      • disadvantages: need to perform the surgery immediately after the injection due to its diffusion to surrounding tissues over time, surgical approach restricted to the injection path, spillage into the pleural space
    • radio nucleotide: Tc 99m
      • disadvantages: need to perform the surgery in the same day after the injection due to the radiotracer half-life, spillage into the pleural space, need for a gamma probe in theater, radiation exposure to all involved medical staff, regulations for of use radioisotopes, and costs
    • india ink
    • barium
      • disadvantages: may cause local inflammation and impact in the pathology assessment
    • ethiodized oil (lipiodol) 
      • disadvantages: potential risk of embolism (intravascular injection)
    • indocyanine green (fluorescence tracer)

Complications

  • pneumothorax: of minimal concern if the surgery is performed immediately after