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Index >  Technique  > Preventing complications
Preventing complications

Until now, we have mainly discussed endoscopic resection from a relatively straightforward theoretical standpoint, but everyday clinical practice is rarely straightforward.

We mentioned earlier that laser resection is palliative rather than curative in the vast majority of cases, i.e., malignant central airway obstruction.

The goal of palliative care is to treat symptoms. In the case of airway obstruction, symptoms must be addressed rapidly and safely, while minimizing discomfort to the patient.

In our view, only the rigid bronchoscope is capable of meeting these goals.

The fiberoptic bronchoscope imposes a number of limitations which make endoscopic resection with this instrument quite fastidious. The bronchoscope must be removed all too often in order to clean the lens and aspirate debris.
In addition, the tip of the laser fiber must be advanced well beyond the lens of the bronchoscope making adjustments difficult. The flexible forceps is too small for adequate removal of large tumor fragments or mechanical debridement. Endoscopic resection with the fiberoptic bronchoscope is therefore slow and often implies prolonged exposure to laser energy, thereby increasing the risk of delayed perforation.
Finally, treatment failures are more common with the flexible bronchoscope because this instrument is not as effective as the rigid bronchoscope in assessing the outcome of a resection.



All of the disadvantages inherent to the flexible fiberoptic bronchoscope make learning to use the rigid bronchoscope worthwhile.

The latter plays a crucial role in preventing complications. It facilitates simultaneous resection, aspiration, and ventilation in a controlled setting.

The suction catheter maintains a clean operating field rendering use of the laser safer, while the large working channel allows ventilation of the patient as needed.

Proper instrumentation and technique are more important to a successful endoscopic resection than the etiology of airway obstruction. Many of our patients are referred to us in respiratory distress.

A patient with malignant tracheal obstruction must be treated rapidly and safely. While it is best to prevent major complications such as hemorrhage or hypoxemia, one must be prepared to deal with them whenever they complicate a given procedure.

Needless to say, it would be hopeless to attempt controlling massive hemorrhage with a fiberoptic instrument.

Besides massive hemorrhage and hypoxemia, the endoscopist will occasionally face other major complications of therapeutic endoscopy, such as airway fire or perforation. Some of these can occur not just during treatment, but also in the immediate post-operative period. For this reason alone, patients undergoing therapeutic endoscopy must be watched closely in the recovery room for at least two hours after the procedure, and hospitalized overnight for observation. In order to avoid procedure related complications, the endoscopic resection must be as complete as possible. Adequate hemostasis and aspiration of secretions, blood and debris at the completion of the procedure are also essential.

The risk of airway perforation is omnipresent, and invariably dangerous, but perforation of certain areas within the tracheobronchial tree can be dramatic.

These include ; The posterior wall of the trachea which is in constant contact with the esophagus, and the distal anterior wall, but also the left main stem origin which is in close proximity to the aorta, pulmonary artery and esophagus, and the left upper lobe bronchus which is surrounded by the pulmonary artery.



The experienced endoscopist will not hesitate to leave tumor behind in these areas in order to avoid a potentially catastrophic situation. It should be noted that the presence of cartilage in the treated airway lumen does not by itself imply perforation. Occasionally, malignant tumors will displace cartilaginous rings toward the airway lumen as they grow. Resection under these circumstances should proceed with extreme caution. In case of perforation, occlusion is possible with « biological glue » (type Tissucol ®). Stenting the airway is another potential solution.

Preventing an airway fire has more to do with common sense than anything else. One must remove all flammable materials such as endotracheal tubes or fiberoptic bronchoscopes from the airway.

High oxygen concentrations should be avoided, and the suction catheter should be transparent and fireproof. By following these simple rules, we have never faced this feared complication in our service.

Both perforation and endobronchial fire are often irreversible. In both cases, prevention is the best option.



Hemorrhage rarely leads to exsanguination by itself. However, a clot obstructing the central airways can cause severe hypoxemia and life-threatening cardiovascular complications. The endoscopist must therefore control even minor bleeding which if left unchecked can lead to a catastrophic clinical scenario equivalent to massive hemorrhage. Continuous aspiration with the rigid bronchoscopic catheter not only keeps the operating field clean by eliminating blood, secretions and smoke from the airway but is also effective in limiting accumulation of secretions in distal airways. On occasion, we face intractable bleeding which can prompt the use of a second catheter in order to facilitate aspiration while at the same time allowing delivery of saline and vasoconstricting drugs to the operating field.

If bleeding does not stop by itself with simple aspiration and rinsing, resection must be interrupted in order to coagulate the bleeding area with the laser.

This technique is somewhat counter-intuitive. Instead of firing the laser directly at the bleeding site, the goal is to treat the periphery of the lesion thereby reducing blood flow to the area. This effect is seen when the tissues surrounding the bleeding lesion are treated. Naturally, it is difficult to specify a given power setting or time interval. Generally, it’s the density of power that counts. It should be weak. Using the YAG laser, 35-40 watts at a distance of 5 mm for approximately one second intervals is often sufficient. During this treatment, the suction catheter must remain in contact with the bleeding lesion aspirating as much blood as possible.

The initial coagulation phase of laser resection often determines the risk of bleeding during a given procedure. The endoscopist should be particularly careful when treating tumors such as carcinoids which can bleed profusely. When a pedunculated tumor is being resected, it is always best to treat the base or pedicle of the tumor where a feeding vessel frequently lies embedded. This vessel must be coagulated thoroughly prior to proceeding with resection in order to avoid massive bleeding.



Perhaps the most common complication encountered during therapeutic endoscopy is hypoxemia. Common causes of hypoxemia during laser resection include ; bleeding, accumulation of debris or secretions in the treated airway, or hypoventilation, to name a few. Whatever the cause, hypoxemia must be corrected immediately in order to avoid serious cardiovascular complications such as life-threatening arrhythmias. The entire team must be vigilant and trained in the proper response to hypoxemia, as the slightest hesitation can lead to catastrophic consequences for the patient.

Fortunately, the advent of continuous pulseoxymetry monitoring has made timely detection of this feared complication possible and rendered therapeutic endoscopy much safer.

The etiology of hypoxia, whether it occurs during or after the procedure, may be multi-factorial, involving the anesthetic, the resection technique, and/or the underlying illness. Naturally, it is difficult to assess the relative importance of all of these factors. Regardless of the cause, treatment of hypoxemia relies heavily on the successful ventilation of healthy lung tissue. For example, in case of unilateral disease, periodic retraction of the tip of the bronchoscope to the level of the carina will allow adequate ventilation of the unaffected lung.



Respiratory decompensation during therapeutic bronchoscopy is common.

For this reason, an inexperienced endoscopist must only treat simple lesions at first, such as moderate sized tumors obstructing a main stem bronchus.

Complex cases such as carinal lesions, bilateral disease, or recurrent tumor following pneumonectomy should be left in the hands of experienced bronchoscopists.

Complex cases characterized by severe obstruction are difficult to treat. In order to ventilate healthy lung parenchyma distal to the obstructed airway, the endoscopist might be forced to advance the bronchoscope forcefully past the obstructing tumor. This is a delicate process which mandates use of the rigid bronchoscope. Either way, one must proceed with extreme caution. Proper technique is essential : First, the lesion must be thoroughly coagulated. Then, the suction catheter is used to probe the lesion in search of a potential passageway for the bronchoscope using the airway’s cartilaginous rings as key landmarks that must be identified before proceeding. The bronchoscope is then advanced in a corkscrew motion.



The exact position of the airway wall and its cartilage are identified by the tactile feedback provided by the bronchoscope itself.

When a tumor fragment is detached it should be immediately removed through the bronchoscope’s side-port using the suction catheter.

Bleeding is limited by the bronchoscope itself which effectively tamponades the airway wall as it advances.

Once the beveled tip of the bronchoscope has overcome the obstacle, retained secretions can be suctioned and the patient ventilated successfully.

Upon completion of the procedure, the rigid bronchoscope should be removed carefully. Any bleeding that takes place can be coagulated with the laser.

It should be noted that this technique is particularly risky in patients who have undergone pneumonectomy. In such cases, the endoscopist must proceed with extreme caution.

Patients with unilateral disease who bleed profusely may be placed in the lateral decubitus position in order to avoid flooding of both lungs. Once hypoxemia is under control, the laser can be used to control the bleeding. A close collaboration between endoscopist and anesthesiologist is essential. Resection must be interrupted at the first sign of hypoxemia. A prompt response to this common complication of therapeutic bronchoscopy is the best guarantee of success.

Unusual complications of therapeutic bronchoscopy include :

Laryngeal dyspnea

This complication may be associated with the treatment of sub-glottic lesions.

The risk is greatest in the setting of vocal cord paralysis, granulomatous inflammation, supra-glottic stenosis, or sub-optimal placement of a Montgomery T tube.

Laryngospasm can be seen in the recovery room and requires prompt attention. If the cause is a Montgomery tube, the stent should be replaced.

Nebulized epinephrine or steroids may also be used on occasion, but sometimes, endotracheal intubation or tracheostomy are necessary.



Mediastinal emphysema or pneumothorax

These are rare complications associated with therapeutic bronchoscopy and are often the result of bronchial perforation or puncture. Chest pain is a common presenting symptom. Auscultation, percussion, and radiographs confirm the diagnosis. In general, no specific treatment is necessary. Chest tube drainage is rarely needed.

Post-operative hyperthermia

This is an unpredictable complication of the procedure.
The treatment is essentially anti-inflammatory. This complication is more common in complicated lengthy cases.

 
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