Pulmonary tissue biopsy

A transthoracic biopsy is performed by a radiologist using a scanner. The patient undergoes a thoracic scan during which the radiologist locates the lesion sought and the biopsy is performed via a needle inserted into the skin (anesthetized in advance) of the rib cage facing the pulmonary lesion. The progression of the needle and its positioning at the heart of the lesion are monitored by the images sent to the thoracic scanner. Once in place the samples are collected by the forward/backward movements of the internal part of the needle. “Mini-core sampling” of the lung tissues to be analyzed are obtained in this way.

This technique can be performed on an out-patient basis, with a 4 to 6 hour monitoring period in hospital after the process. The most frequent risks are pneumothorax (10-50% of cases) and local hemorrhage (20-40% of cases). The chances of making the diagnosis using this technique are very high at almost 90%

As its name indicates, an endobronchial biopsy is performed inside the airways. It is performed by the pulmonologist and requires the use of a bronchoscope which is a flexible endoscope the size of an electric cable and which has a miniaturized camera at its end. This enables the progression of the endoscope from the mouth (or nose) to be monitored up to the lesion via natural airways. The instrument follows the same path as the air when the patient breathes. Based on the location of the lesion (lung or mediastinum nodes), this technique in performed in conjunction with ultrasound identification (in order to avoid accidental puncture of blood vessels) or with electromagnetic guidance (an equivalent to GPS used in cars).

This technique can also be performed on an outpatient basis requiring several hours of hospital monitoring after the process. However, the vast majority of cases require general anesthesia of 30 to 40 minutes to ensure the comfort of the patient and the movement precision of the examiner.

All these techniques are performed routinely by the interventional pulmonology unit at the HUG, and some of them such as guidance by electromagnetic navigation are pioneering in Switzerland. The risks of pneumothorax (1-5% of cases) and local hemorrhage (3-5% of cases) are much lower than with a transthoracic biopsy. The chances of making a diagnosis using endoscopy vary from 70 to >90%, depending on the collection technique used (direct, ultrasound, electromagnetic navigation)