Electromagnetic Navigation Bronchoscopy: GPS like navigation throughout the lung
This is an adjunct to standard flexible bronchoscopy.
Flexible bronchoscopy is safe and effective procedure that allows examination of the main tracheal and larger bronchial airways with a fiberoptic scope as shown below.
But due to the physical size and maneuverabilty of the scope, it’s ability to reach the peripheral lung nodules and smaller mid-lung lesions is much less accurate even with X-ray/ fluoroscopic help.
Electromagnetic Navigational Bronchoscopy (ENB)/ Navibronch uses the flexible bronchoscope as an access / delivery platform for insertion of a steerable catheter to navigate through smaller distal airways anywhere in the lung utilizing a system of elctromagnetic navigation that synchronizes the patients CT Scan with their airways, similar to using GPS navigation in your car.
As one of the first Thoracic Surgeons in the country to adopt this technology, I have been doing ENB since 2008 and have performed around a 1000 procedures. We found out early on that this technology was very beneficial to helping us diagnose lung cancer earlier with fewer complications than other methods:
Publication LINK: ENB performed by Thoracic Surgeons: One Center’s early Success
If you watch the next demonstration video you will see my good friend and colleague Dr Kyle Hogarth from University of Chicago demonstrating the specifics and benefits of Navigational Bronchoscopy.
(I have just published a recent paper with Dr Kyle Hogarth, Dr Tom Gildea of Cleavland Clinic and Dr David Wilson on the cost of delayed diagnosis of lung cancer)
Click this link: Analysis of the cost of delays in diagnosing lung cancer
The technology involved is described below:
First a detailed CT scan is performed and the images loaded into a computer that generates a 3D exact virtual image of the patients airways.
Next a pathway leading to the lung nodule in question is planned out. The data plan is transferred to the working navigation computer and bronchoscopy is begun.
The patient is anesthetized, the flexible bronchoscope is inserted via the mouth and airway and the main central airways are examined. Then a steerable guide catheter with a sheath over it is inserted in the bronchoscope.
The patient is lying on a board that generates an electromagnetic field over the chest cavity. Additional sensors are placed to help track and adjust for normal respiratory motion. The computer system synchronizes the patients CT scan images with the examined native airways and allows location sensing and navigation to distal lung lesions similar to navigating your car with GPS.
The CT scan data once uploaded to the computer is then used to generate a “virtual airway” map that is anatomically specific to that patient. Specific points along the airway are identified. Then flexible bronchoscopy is started and the sensor probe is placed down the bronchoscope to identifies and match up the delineated CT Scan points with the live waypoints in the actual airway thus acheiving synchronization. See video below.
Electromagnetic Navigation Bronchoscopy Planning and Registration video
Now movement of the steerable probe is tracked and can be directed via the computer image.
Once the location is reached, needle, brush, forceps biopsies can be done, along with lavage/ washing the area for cells. I addition fiducial markers (gold seeds) can be placement that are used for Cyberknife/ Sterotactic Body Radiation Therapy SBRT or as a Surgical resection aids.
In addition to getting a diagnosis, for small sub-pleural nodules the immediate area can be dye-tattooed to faciltate thorascopic/ robotic resection of a non visible small lung lesion, as demostrated in the video below.
ENB is usually performed by pulmonologists or thoracic surgeons and is done with either concious sedation (mild anesthesia) or general anethesia (fully asleep) depending upon the operators preferance.
It is an outpatient procedure that may take 1.5-2 hours start to finish. You then will be observed in the recovery area for about an hour.
This is an alternative procedure to CT guided biopsy, both which are excellant ways to biopsy a suspicious lung nodule. Each procedure has its own strenths and weaknesses depending mostly upon the size and location of the nodule and the presence of significant lung disease i.e. COPD which can dramatically increase the risk of a pneumothorax (collapsed lung) with CT guided biopsy. Per NIH data the overall average risk of a collapse lung with CT guided/TTNA biopsy is 15%.
A pnemothorax can occur with ENB also, though much less frequent (2-5%). This is why all patients get a post procedure chest X-ray looking for a collapsed lung, and are observed for a while. Usually if they have a pneumothorax they complain of shortness of breath and have some chest pain, but not always. If it is small in size the patient may just be watched for a while, possibly in hospital overnight. If it is large or expanding they may require a chest tube.
This is a small drain placed between the ribs to evacuate air that has leaked out from the lung into the chest caivty. This usually is in place for 2-3 days while the lung heals before it can be removed.
The other riskes to any lung biopsy procedure are mainly bleeding and shortness of breath. You may also have a sore throat and some mild chest pain for a day after and ENB due to the breathing tube used. It is common to cough up small amounts of old dark blood for 1-2 days after your biopsy. Any develoupment of worsening chest pain, shortness of breath or continued amounts of blood coughed up requires immediate attention and your doctor should be notified or go to the closest emergeny room.
In general these procedures are very safe and ENB has been performed over 60,000 times world-wide in the past 10 years with overall excellant published results.
We have a pathologist in the room looking at some of the biopsies to give us feedback regarding the character of the biopsy and if it reflects abnormal lung tissue. This information helps us redirect biopsies if we are not getting diagnostic material. We always share whatever information the pathologist tells us with the patient and family that day, however this does not mean we will have a definitive answer that day.
All specimens are carefully analyzed and cultures started so final pathologic results may take at least 2-3 working days and the cultures planted looking for possible slow growing atypical infections like fungus and tuberculosis are monitored for up to six weeks.
Electromagnetic Navigation Bronchoscopy may be a good option for you, check with your pulmonologist or thoracic surgeon to see if this is available at your hospital. This Technology has greatly enhanced our ability to safely diagnose, target lung cancers for minimally invasive surgical resection and Cyberknife radio-surgical treatment.
But never forget our most powerful weapon against cancer is always Hope!